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Sample records for acute hypercapnic ventilatory

  1. Morphine has latent deleterious effects on the ventilatory responses to a hypoxic-hypercapnic challenge.

    PubMed

    May, Walter J; Henderson, Fraser; Gruber, Ryan B; Discala, Joseph F; Young, Alex P; Bates, James N; Palmer, Lisa A; Lewis, Stephen J

    2013-08-28

    This study explored the concept that morphine has latent deleterious actions on the ventilatory control systems that respond to a hypoxic-hypercapnic challenge. In this study, we examined the ventilatory responses elicited by hypoxic-hypercapnic challenge in conscious rats at a time when the effects of morphine (10 mg/kg) on arterial blood-gas chemistry and minute ventilation had subsided. Morphine induced pronounced changes in arterial blood-gas chemistry (e.g., an increase in pCO2, decreases in pO2 and sO2) and decreases in minute ventilation. Despite the complete resolution of the morphine-induced changes in arterial blood-gas chemistry and minute ventilation and almost complete resolution of the effects on peak inspiratory flow and peak expiratory flow, subsequent exposure to hypoxic-hypercapnic challenge elicited markedly blunted increases in minute ventilation and in peak inspiratory and expiratory flows. These findings demonstrate that (1) the changes in arterial blood-gas chemistry elicited by morphine parallel changes in minute ventilation rather than PIF and PEF, and (2) morphine has latent untoward effects on the ventilatory responses to hypoxic-hypercapnic challenge. These novel findings raise the possibility that patients deemed to have recovered from the acute ventilatory depressant effects of morphine may still be susceptible to the latent effects of this opioid analgesic. The mechanisms underlying these latent effects remain to be elucidated. PMID:25045592

  2. Controversies involving hypercapnic acidosis in acute respiratory distress syndrome.

    PubMed

    Nardelli, Liliane; Rocco, Patricia Rieken Macedo; Garcia, Cristiane Sousa Nascimento Baez

    2009-12-01

    Acute respiratory distress syndrome is characterized by a diffuse inflammatory reaction of lung parenchyma induced by a direct insult to the alveolar epithelium (pulmonary acute respiratory distress syndrome) or an indirect lesion through the vascular endothelium (extrapulmonary acute respiratory distress syndrome). The main therapeutic strategy for acute respiratory distress syndrome is the ventilatory support. However, mechanical ventilation can worsen lung injury. In this context, a protective ventilatory strategy with low tidal volume has been proposed. The use of low tidal volume reduced the mortality rate of acute respiratory distress syndrome patients, but result in hypercapnic acidosis. The current article presents a review of literature on the effects of permissive hypercapnia in acute respiratory distress syndrome. To that end, we carried out a systematic review of scientific literature based on established criteria for documental analysis including clinical and experimental articles, using as data bases MedLine, LILACS, SciELO, PubMed, Cochrane. Hypercapnic acidosis has been considered by some authors as a modulator of the inflammatory process of acute respiratory distress syndrome. However, clinical and experimental studies on the effects of hypercapnic acidosis have shown controversial results. Therefore it is important to better elucidate the role of hypercapnic acidosis in acute respiratory distress syndrome.

  3. Periaqueductal gray matter modulates the hypercapnic ventilatory response.

    PubMed

    Lopes, Luana T; Patrone, Luis G A; Bícego, Kênia C; Coimbra, Norberto C; Gargaglioni, Luciane H

    2012-08-01

    The periaqueductal gray (PAG) is a midbrain structure directly involved in the modulation of defensive behaviors. It has direct projections to several central nuclei that are involved in cardiorespiratory control. Although PAG stimulation is known to elicit respiratory responses, the role of the PAG in the CO(2)-drive to breathe is still unknown. The present study assessed the effect of chemical lesion of the dorsolateral and dorsomedial and ventrolateral/lateral PAG (dlPAG, dmPAG, and vPAG, respectively) on cardiorespiratory and thermal responses to hypercapnia. Ibotenic acid (IBO) or vehicle (PBS, Sham group) was injected into the dlPAG, dmPAG, or vPAG of male Wistar rats. Rats with lesions outside the dlPAG, dmPAG, or vPAG were considered as negative controls (NC). Pulmonary ventilation (VE: ), mean arterial pressure (MAP), heart rate (HR), and body temperature (Tb) were measured in unanesthetized rats during normocapnia and hypercapnic exposure (5, 15, 30 min, 7 % CO(2)). IBO lesioning of the dlPAG/dmPAG caused 31 % and 26.5 % reductions of the respiratory response to CO(2) (1,094.3 ± 115 mL/kg/min) compared with Sham (1,589.5 ± 88.1 mL/kg/min) and NC groups (1,488.2 ± 47.7 mL/kg/min), respectively. IBO lesioning of the vPAG caused 26.6 % and 21 % reductions of CO(2) hyperpnea (1,215.3 ± 108.6 mL/kg/min) compared with Sham (1,657.3 ± 173.9 mL/kg/min) and NC groups (1,537.6 ± 59.3). Basal VE: , MAP, HR, and Tb were not affected by dlPAG, dmPAG, or vPAG lesioning. The results suggest that dlPAG, dmPAG, and vPAG modulate hypercapnic ventilatory responses in rats but do not affect MAP, HR, or Tb regulation in resting conditions or during hypercapnia.

  4. Ventilatory function assessment in safety pharmacology: Optimization of rodent studies using normocapnic or hypercapnic conditions

    SciTech Connect

    Goineau, Sonia; Rompion, Sonia; Guillaume, Philippe; Picard, Sandra

    2010-09-15

    Although the whole body plethysmography for unrestrained animals is the most widely used method to assess the respiratory risk of new drugs in safety pharmacology, non-appropriate experimental conditions may mask deleterious side effects of some substances. If stimulant or bronchodilatory effects can be easily evidenced in rodents under standard experimental conditions, i.e. normal air breathing and diurnal phase, drug-induced respiratory depression remains more difficult to detect. This study was aimed at comparing the responsiveness of Wistar rats, Duncan Hartley guinea-pigs or BALB/c mice to the respiratory properties of theophylline (50 or 100 mg/kg p.o.) or morphine (30 mg/kg i.p.) under varying conditions (100% air versus 5% CO{sub 2}-enriched air, light versus dark day phase), in order to select the most appropriate experimental conditions to each species for safety airway investigations. Our results showed that under normocapnia the ventilatory depressant effects of morphine can be easily evidenced in mice, slightly observed in guinea-pigs and not detected in rats in any day phase. Slight hypercapnic conditions enhanced the responsiveness of rats to morphine but not that of guinea-pigs and importantly they did not blunt the airway responsiveness of rats to the stimulation and bronchodilation evoked by theophylline, the most widely used reference agent in safety pharmacology studies. In conclusion, hypercapnic conditions associated with the non-invasive whole body plethysmography should be considered for optimizing the assessment of both the ventilatory depressant potential of morphine-like substances or the respiratory stimulant effects of new drugs in the rat, the most extensively used species in rodent safety and toxicological investigations.

  5. Hypercapnic ventilatory response in humans before, during, and after 23 days of low level CO2 exposure

    NASA Technical Reports Server (NTRS)

    Elliott, A. R.; Prisk, G. K.; Schollmann, C.; Hoffmann, U.

    1998-01-01

    Alterations in ventilation and the chemoreceptor response to CO2 during 23 d of 1.2% inspired CO2 were studied in four male subjects. Resting ventilation (VE), tidal volume (VT), respiratory frequency (fR), inspired and end tidal O2 and CO2 and the hypercapnic ventilatory response (HCVR) measured by CO2 rebreathing were measured once before entering the chamber, on days 2, 5, 11, and 22 of CO2 exposure, and one day after. Resting VE slightly increased (5%) on day 2 of exposure and significantly increased (22%) by day 5 followed by a progressive decrease to pre-chamber levels by day 22 and on the first day of recovery. Tidal volume and fR were not statistically different. During the exposure PetCO2 was significantly elevated with day 2 having the largest increase (19.6%). PetCO2 returned to normal within 24 h post exposure. The HCVR was characterized by the slope (SHCVR), intercept at zero ventilation (B), and the ventilation at a PCO2 = 60 mmHg (VE60). The SHCVR decreased (14%) on day 2, but was not significant; the SHCVR on the other exposure days were also not different. The SHCVR on the first recovery day significantly increased (37%). The HCVR B was shifted to the right on day 2 by 5.2 mmHg, then progressively returned to the pre-exposure position. On recovery the B significantly shifted 6.9 mmHg to the right of pre-exposure B. The VE60 decreased by approximately 32% and 16% on day 2 and 5, respectively, then returned within pre-exposure range for the remainder of the exposure and during recovery. During the early phase and one day after the exposure the HCVR was right shifted. One day after exposure chemoreceptor sensitivity to elevated CO2 was increased but, the B was right shifted resulting in a reduced HCVR below PCO2 of 60 mmHg and a greater HCVR above 60 mmHg.

  6. Applying a low-flow CO2 removal device in severe acute hypercapnic respiratory failure.

    PubMed

    Sharma, Ajay S; Weerwind, Patrick W; Strauch, Uli; van Belle, Arne; Maessen, Jos G; Wouters, Emiel F M

    2016-03-01

    A novel and portable extracorporeal CO2-removal device was evaluated to provide additional gas transfer, auxiliary to standard therapy in severe acute hypercapnic respiratory failure. A dual-lumen catheter was inserted percutaneously in five subjects (mean age 55 ± 0.4 years) and, subsequently, connected to the CO2-removal device. The median duration on support was 45 hours (interquartile range 26-156), with a blood flow rate of approximately 500 mL/min. The mean PaCO2 decreased from 95.8 ± 21.9 mmHg to 63.9 ± 19.6 mmHg with the pH improving from 7.11 ± 0.1 to 7.26 ± 0.1 in the initial 4 hours of support. Three subjects were directly weaned from the CO2-removal device and mechanical ventilation, one subject was converted to ECMO and one subject died following withdrawal of support. No systemic bleeding or device complications were observed. Low-flow CO2 removal adjuvant to standard therapy was effective in steadily removing CO2, limiting the progression of acidosis in subjects with severe acute hypercapnic respiratory failure.

  7. Noninvasive ventilatory correction as an adjunct to an experimental systemic reperfusion therapy in acute ischemic stroke.

    PubMed

    Barlinn, Kristian; Balucani, Clotilde; Palazzo, Paola; Zhao, Limin; Sisson, April; Alexandrov, Andrei V

    2010-01-01

    Background. Obstructive sleep apnea (OSA) is a common condition in patients with acute ischemic stroke and associated with early clinical deterioration and poor functional outcome. However, noninvasive ventilatory correction is hardly considered as a complementary treatment option during the treatment phase of acute ischemic stroke. Summary of Case. A 55-year-old woman with an acute middle cerebral artery (MCA) occlusion received intravenous tissue plasminogen activator (tPA) and enrolled into a thrombolytic research study. During tPA infusion, she became drowsy, developed apnea episodes, desaturated and neurologically deteriorated without recanalization, re-occlusion or intracerebral hemorrhage. Urgent noninvasive ventilatory correction with biphasic positive airway pressure (BiPAP) reversed neurological fluctuation. Her MCA completely recanalized 24 hours later. Conclusions. Noninvasive ventilatory correction should be considered more aggressively as a complementary treatment option in selected acute stroke patients. Early initiation of BiPAP can stabilize cerebral hemodynamics and may unmask the true potential of other therapies. PMID:21052540

  8. Review of ventilatory techniques to optimize mechanical ventilation in acute exacerbation of chronic obstructive pulmonary disease

    PubMed Central

    Reddy, Raghu M; Guntupalli, Kalpalatha K

    2007-01-01

    Chronic obstructive pulmonary disease (COPD) is a major global healthcare problem. Studies vary widely in the reported frequency of mechanical ventilation in acute exacerbations of COPD. Invasive intubation and mechanical ventilation may be associated with significant morbidity and mortality. A good understanding of the airway pathophysiology and lung mechanics in COPD is necessary to appropriately manage acute exacerbations and respiratory failure. The basic pathophysiology in COPD exacerbation is the critical expiratory airflow limitation with consequent dynamic hyperinflation. These changes lead to further derangement in ventilatory mechanics, muscle function and gas exchange which may result in respiratory failure. This review discusses the altered respiratory mechanics in COPD, ways to detect these changes in a ventilated patient and formulating ventilatory techniques to optimize management of respiratory failure due to exacerbation of COPD. PMID:18268918

  9. Prevention of experimental stroke by hypercapnic-hypoxic preconditioning.

    PubMed

    Yakushev, N N; Bespalov, A G; Kulikov, V P

    2008-09-01

    The effectiveness of hypercapnic hypoxic training in the prevention of acute disturbances in cerebral circulation was studied under experimental conditions. Hypercapnic hypoxic training was followed by a significant decrease in the severity of neurological deficit and locomotor and coordination disorders after cerebral ischemic injury. PMID:19240841

  10. [Acute altitude sickness and ventilatory function in subjects intermittently exposed to hypobaric hypoxia].

    PubMed

    Saldías, F; Beroíza, T; Lisboa, C

    1995-01-01

    Aiming to assess the magnitude of acute mountain sickness symptoms and ventilatory function in subjects intermittently exposed to hypobaric hypoxia, we studied 48 healthy men aged 32.6 +/- 8.2 years old who worked in a gold mine at a altitude of 4600 m, using a schedule of 8-12 days of work at the mine followed by 4 days of rest at the sea level. Studies were performed at the sea level (A), during the first two days of ascension (B) and after three or four days of stay at 4600 m (C). Mountain sickness symptoms were evaluated with a questionnaire devised in the 1991 International Hypoxia Symposium and respiratory function was assessed with a Collins Eagle II respirometer, following American Thoracic Society recommendations. Subjects reported mild to moderate symptoms during the first 24 hours of ascending (mean score of 6.4 +/- 3.1 for a maximum of 15). Forced vital capacity fell significantly in period B and returned to normal in period C and forced expiratory volume in 1 s did not change in any period. However, maximal expiratory flow and maximal midexpiratory flow rate significantly increased and remained elevated during the four days stay at the mine. No correlation was found between acute mountain sickness symptoms and changes in ventilatory function.

  11. Ventilatory effects of substance P-saporin lesions in the nucleus tractus solitarii of chronically hypoxic rats

    PubMed Central

    Fu, Zhenxing; Powell, Frank L.

    2011-01-01

    During ventilatory acclimatization to hypoxia (VAH), time-dependent increases in ventilation lower Pco2 levels, and this persists on return to normoxia. We hypothesized that plasticity in the caudal nucleus tractus solitarii (NTS) contributes to VAH, as the NTS receives the first synapse from the carotid body chemoreceptor afferents and also contains CO2-sensitive neurons. We lesioned cells in the caudal NTS containing the neurokinin-1 receptor by microinjecting the neurotoxin saporin conjugated to substance P and measured ventilatory responses in awake, unrestrained rats 18 days later. Lesions did not affect hypoxic or hypercapnic ventilatory responses in normoxic control rats, in contrast to published reports for similar lesions in other central chemosensitive areas. Also, lesions did not affect the hypercapnic ventilatory response in chronically hypoxic rats (inspired Po2 = 90 Torr for 7 days). These results suggest functional differences between central chemoreceptor sites. However, lesions significantly increased ventilation in normoxia or acute hypoxia in chronically hypoxic rats. Hence, chronic hypoxia increases an inhibitory effect of neurokinin-1 receptor neurons in the NTS on ventilatory drive, indicating that these neurons contribute to plasticity during chronic hypoxia, although such plasticity does not explain VAH. PMID:21593425

  12. Acute effects of jaw clenching using a customized mouthguard on anaerobic ability and ventilatory flows.

    PubMed

    Morales, Jose; Buscà, Bernat; Solana-Tramunt, Mònica; Miró, Adrià

    2015-12-01

    The latest findings on the ergogenic effects of a dentistry-design, bite-aligning mouthpiece require additional research to assess its impact on anaerobic ability and ventilatory parameters. This paper was aimed at determining the ergogenic acute effects of wearing a custom-made mouthpiece on oral airflow dynamics, 30-s Wingate Anaerobic Test performance parameters. Twenty-eight healthy and physically-active male subjects (age: 24.50 ± 3.32, height: 181.34 ± 7.4, weight: 78.14 ± 8.21), were voluntarily studied. The subjects were first briefed on the test protocols, and then performed the 30s Wingate test and Spirometer test. The experimental trials were performed in a random counterbalanced order. We evaluate maximum expiratory volume (VEmax L min(-1)), mean power (W kg(-1)), peak power (W kg(-1)), time to peak (s), rate to fatigue (Ws(-1)) and lactate production (mMol L(-1)), rate of perceived exertion (RPE). There were significant differences between mouthguard and no-mouthguard conditions in mean power (W kg(-1)), peak power (W kg(-1)), time to peak (s), and rate to fatigue (Ws(-1)) for the 30-s Wingate Anaerobic Test. Significantly lower lactate production (mMol L(-1)) was observed, in mouthguard condition but no significant differences were found in RPE. In airflow dynamics, the VEmax L min(-1) was significantly higher when comparing the mouthguard and the no mouthguard conditions in both forced and unforced conditions. In conclusion, wearing a customized mouthguard improves anaerobic ability and increases forced expiratory volume. This study will help practitioners improve athlete's performance in anaerobic activities where high intensity action might provoke jaw-clenching, contributing in reductions of lactate and fatigue, and improving ventilatory parameters.

  13. Ventilatory function in rubber processing workers: acute changes over the workshift.

    PubMed Central

    Governa, M; Comai, M; Valentino, M; Antonicelli, L; Rinaldi, F; Pisani, E

    1987-01-01

    When considering rubber tyre manufacturing from an occupational health viewpoint, three areas may be identified in which exposure to respirable materials are potentially harmful: the processing, curing, and talc areas. A study of the ventilatory function of the entire work force employed in the processing area in a rubber tyre manufacturing plant was undertaken to determine whether an acute reduction in lung function occurs over the course of their working shift (the plant worked a three shift system) and whether a chronic exposure to the occupational airborne contaminants causes permanent changes in lung function. The ventilatory function was measured at the worksite at the beginning and immediately after the end of the workshift. No evidence of chronic obstructive pulmonary disease was found and in most cases no significant decline in FEV1 was observed. Only one of the 79 individuals showed a moderate obstruction, measured by the ratio FEV1/FVC which gave the value of 0.55, with no variation over the shift. For non-smokers, the FVC, FEV1, and FEF25-75% were lower in those exposed for more than five years than in those exposed for five years or less. A similar pattern was also observed in the FVC and FEV1 of the smokers. None of these differences was statistically significant. Within each exposure group the pulmonary function of the smokers was lower than that of the non-smokers, but the only significant difference was found in the values of FEF25-75%. Only one man showed a decline in the FEV1/FVC ratio over the shift, but during each shift, a decrease in all the lung function tests was observed. The decrease was smallest during the first of the three shifts. These results are thought to support the hypothesis that there are acute adverse effects over an eight hour shift. Further investigations are needed to discover whether these acute changes in lung function result from a chemical stimulation or irritant receptors in the airways. PMID:3814549

  14. Effects of clinically relevant acute hypercapnic and metabolic acidosis on the cardiovascular system: an experimental porcine study

    PubMed Central

    2013-01-01

    Introduction Hypercapnic acidosis (HCA) that accompanies lung-protective ventilation may be considered permissive (a tolerable side effect), or it may be therapeutic by itself. Cardiovascular effects may contribute to, or limit, the potential therapeutic impact of HCA; therefore, a complex physiological study was performed in healthy pigs to evaluate the systemic and organ-specific circulatory effects of HCA, and to compare them with those of metabolic (eucapnic) acidosis (MAC). Methods In anesthetized, mechanically ventilated and instrumented pigs, HCA was induced by increasing the inspired fraction of CO2 (n = 8) and MAC (n = 8) by the infusion of HCl, to reach an arterial plasma pH of 7.1. In the control group (n = 8), the normal plasma pH was maintained throughout the experiment. Hemodynamic parameters, including regional organ hemodynamics, blood gases, and electrocardiograms, were measured in vivo. Subsequently, isometric contractions and membrane potentials were recorded in vitro in the right ventricular trabeculae. Results HCA affected both the pulmonary (increase in mean pulmonary arterial pressure (MPAP) and pulmonary vascular resistance (PVR)) and systemic (increase in mean arterial pressure (MAP), decrease in systemic vascular resistance (SVR)) circulations. Although the renal perfusion remained unaffected by any type of acidosis, HCA increased carotid, portal, and, hence, total liver blood flow. MAC influenced the pulmonary circulation only (increase in MPAP and PVR). Both MAC and HCA reduced the stroke volume, which was compensated for by an increase in heart rate to maintain (MAC), or even increase (HCA), the cardiac output. The right ventricular stroke work per minute was increased by both MAC and HCA; however, the left ventricular stroke work was increased by HCA only. In vitro, the trabeculae from the control pigs and pigs with acidosis showed similar contraction force and action-potential duration (APD). Perfusion with an acidic

  15. Enhanced non-eupneic breathing following hypoxic, hypercapnic or hypoxic-hypercapnic gas challenges in conscious mice

    PubMed Central

    Getsy, Paulina M.; Davis, Jesse; Coffee, Gregory A.; May, Walter J.; Palmer, Lisa A.; Strohl, Kingman P.; Lewis, Stephen J.

    2014-01-01

    C57BL6 mice display non-eupneic breathing and spontaneous apneas during wakefulness and sleep as well as markedly disordered breathing following cessation of a hypoxic challenge. We examined whether (1) C57BL6 mice display marked non-eupneic breathing following hypercapnic or hypoxic-hypercapnic challenges, and (2) compared the post-hypoxia changes in non-eupneic breathing of C57BL6 mice to those of B6AF1 (57BL6 dam × A/J sire) and Swiss-Webster mice, which display different ventilatory responses than C57BL6 mice. C57BL6 mice displayed marked increases in respiratory frequency and non-eupneic breathing upon return to room-air after hypoxic (10% O2, 90% N2), hypercapnic (5% CO2, 21% O2, 74% N2) and hypoxic-hypercapnic (10% O2, 5% CO2, 85% N2) challenges. B6AF1 mice displayed less tachypnea and reduced non-eupneic breathing post-hypoxia, whereas Swiss-Webster mice displayed robust tachypnea with minimal increases in non-eupneic breathing post-hypoxia. These studies demonstrate that non-eupneic breathing increases after physiologically-relevant hypoxic-hypercapnic challenge in C57BL6 mice and suggest that further studies with these and B6AF1 and Swiss-Webster mice will help define the genetics of non-eupneic breathing. PMID:25242462

  16. Chronic intermittent hypoxia alters ventilatory and metabolic responses to acute hypoxia in rats.

    PubMed

    Morgan, Barbara J; Adrian, Russell; Wang, Zun-Yi; Bates, Melissa L; Dopp, John M

    2016-05-15

    We determined the effects of chronic exposure to intermittent hypoxia (CIH) on chemoreflex control of ventilation in conscious animals. Adult male Sprague-Dawley rats were exposed to CIH [nadir oxygen saturation (SpO2), 75%; 15 events/h; 10 h/day] or normoxia (NORM) for 21 days. We assessed the following responses to acute, graded hypoxia before and after exposures: ventilation (V̇e, via barometric plethysmography), V̇o2 and V̇co2 (analysis of expired air), heart rate (HR), and SpO2 (pulse oximetry via neck collar). We quantified hypoxia-induced chemoreceptor sensitivity by calculating the stimulus-response relationship between SpO2 and the ventilatory equivalent for V̇co2 (linear regression). An additional aim was to determine whether CIH causes proliferation of carotid body glomus cells (using bromodeoxyuridine). CIH exposure increased the slope of the V̇e/V̇co2/SpO2 relationship and caused hyperventilation in normoxia. Bromodeoxyuridine staining was comparable in CIH and NORM. Thus our CIH paradigm augmented hypoxic chemosensitivity without causing glomus cell proliferation. PMID:26917692

  17. Behavioral, Ventilatory and Thermoregulatory Responses to Hypercapnia and Hypoxia in the Wistar Audiogenic Rat (WAR) Strain

    PubMed Central

    Giusti, Humberto; Oliveira, José Antonio; Glass, Mogens Lesner; Garcia-Cairasco, Norberto

    2016-01-01

    Introduction We investigated the behavioral, respiratory, and thermoregulatory responses elicited by acute exposure to both hypercapnic and hypoxic environments in Wistar audiogenic rats (WARs). The WAR strain represents a genetic animal model of epilepsy. Methods Behavioral analyses were performed using neuroethological methods, and flowcharts were constructed to illustrate behavioral findings. The body plethysmography method was used to obtain pulmonary ventilation (VE) measurements, and body temperature (Tb) measurements were taken via temperature sensors implanted in the abdominal cavities of the animals. Results No significant difference was observed between the WAR and Wistar control group with respect to the thermoregulatory response elicited by exposure to both acute hypercapnia and acute hypoxia (p>0.05). However, we found that the VE of WARs was attenuated relative to that of Wistar control animals during exposure to both hypercapnic (WAR: 133 ± 11% vs. Wistar: 243 ± 23%, p<0.01) and hypoxic conditions (WAR: 138 ± 8% vs. Wistar: 177 ± 8%; p<0.01). In addition, we noted that this ventilatory attenuation was followed by alterations in the behavioral responses of these animals. Conclusions Our results indicate that WARs, a genetic model of epilepsy, have important alterations in their ability to compensate for changes in levels of various arterial blood gasses. WARs present an attenuated ventilatory response to an increased PaCO2 or decreased PaO2, coupled to behavioral changes, which make them a suitable model to further study respiratory risks associated to epilepsy. PMID:27149672

  18. Acute ventilatory responses to hypoxia during voluntary and electrically induced leg exercise in man.

    PubMed Central

    Pandit, J J; Robbins, P A

    1994-01-01

    1. The acute ventilatory response to a brief period of hypoxia (AHVR) was measured in six subjects (a) at rest, (b) during electrically induced leg exercise (EEL), (c) during voluntary leg exercise at an external work rate matched to electrical exercise (EV1) and (d) during voluntary leg exercise at an internal work rate (i.e. metabolic rate) matched to electrical exercise (EV2). The end-tidal PO2 during hypoxia was 50 mmHg and the end-tidal PCO2 was held constant at 1-2 mmHg above resting values throughout each of these four protocols. 2. EEL was produced by surface electrode stimulation of the quadriceps muscles so as to cause the legs to extend at the knee and lift a set of weights via a pulley system. During EV1, each subject lifted the same weight through the same height and at the same frequency as during his EEL protocol. During EV2, the weight, the height through which it was lifted and the frequency of voluntary contractions were altered to produce a similar O2 consumption and CO2 production as during EEL. 3. In each subject, end-tidal PCO2 values showed no change between the four protocols, and in three subjects in whom they were measured, arterial PCO2 values were also similar between the protocols. Venous lactate levels did not increase after EEL or EV2. 4. The AHVR during EEL (14.1 +/- 1.42 l min-1; mean +/- S.E.M) was significantly increased (Student's paired t test) compared with rest (7.55 +/- 1.10 l min-1; P < 0.003).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8071883

  19. Lung Transcriptomics during Protective Ventilatory Support in Sepsis-Induced Acute Lung Injury

    PubMed Central

    Acosta-Herrera, Marialbert; Lorenzo-Diaz, Fabian; Pino-Yanes, Maria; Corrales, Almudena; Valladares, Francisco; Klassert, Tilman E.; Valladares, Basilio; Slevogt, Hortense; Ma, Shwu-Fan

    2015-01-01

    Acute lung injury (ALI) is a severe inflammatory process of the lung. The only proven life-saving support is mechanical ventilation (MV) using low tidal volumes (LVT) plus moderate to high levels of positive end-expiratory pressure (PEEP). However, it is currently unknown how they exert the protective effects. To identify the molecular mechanisms modulated by protective MV, this study reports transcriptomic analyses based on microarray and microRNA sequencing in lung tissues from a clinically relevant animal model of sepsis-induced ALI. Sepsis was induced by cecal ligation and puncture (CLP) in male Sprague-Dawley rats. At 24 hours post-CLP, septic animals were randomized to three ventilatory strategies: spontaneous breathing, LVT (6 ml/kg) plus 10 cmH2O PEEP and high tidal volume (HVT, 20 ml/kg) plus 2 cmH2O PEEP. Healthy, non-septic, non-ventilated animals served as controls. After 4 hours of ventilation, lung samples were obtained for histological examination and gene expression analysis using microarray and microRNA sequencing. Validations were assessed using parallel analyses on existing publicly available genome-wide association study findings and transcriptomic human data. The catalogue of deregulated processes differed among experimental groups. The ‘response to microorganisms’ was the most prominent biological process in septic, non-ventilated and in HVT animals. Unexpectedly, the ‘neuron projection morphogenesis’ process was one of the most significantly deregulated in LVT. Further support for the key role of the latter process was obtained by microRNA studies, as four species targeting many of its genes (Mir-27a, Mir-103, Mir-17-5p and Mir-130a) were found deregulated. Additional analyses revealed 'VEGF signaling' as a central underlying response mechanism to all the septic groups (spontaneously breathing or mechanically ventilated). Based on this data, we conclude that a co-deregulation of 'VEGF signaling' along with 'neuron projection

  20. Ventilatory response to acute hypoxia in transgenic mice over-expressing erythropoietin: effect of acclimation to 3-week hypobaric hypoxia.

    PubMed

    Villafuerte, Francisco C; Cárdenas-Alayza, Rosa; Macarlupú, José Luis; Monge-C, Carlos; León-Velarde, Fabiola

    2007-09-30

    We used transgenic mice constitutively over-expressing erythropoietin ("tg6" mice) and wild-type (wt) mice to investigate whether the high hematocrit (hct), consequence of Epo over-expression affected: (1) the normoxic ventilation (V (E)) and the acute hypoxic ventilatory response (HVR) and decline (HVD), (2) the increase in ventilation observed after chronic exposure to hypobaric hypoxia (430mmHg for 21 days), (3) the respiratory "blunting", and (4) the erythrocythemic response induced by chronic hypoxia exposure. V (E) was found to be similar in tg6 and wt mice in normoxia (FIO2=0.21). Post-acclimation V (E) was significantly elevated in every time point in wt mice at FIO2=0.10 when compared to pre-acclimation values. In contrast, tg6 mice exhibited a non-significant increase in V (E) throughout acute hypoxia exposure. Changes in V (E) are associated with adjustments in tidal volume (V(T)). HVR and HVD were independent of EE in tg6 and wt mice before chornic hypoxia exposure. HVR was significantly greater in wt than in tg6 mice after chronic hypoxia. After acclimation, HVD decreased in tg6 mice. Chronic hypoxia exposure caused hct to increase significantly in wt mice, while only a marginal increase occurred in the tg6 group. Although pre-existent EE does not appear to have an effect on HVR, the observation of alterations on V(T) suggests that it may contribute to time-dependent changes in ventilation and in the acute HVR during exposure to chronic hypoxia. In addition, our results suggest that EE may lead to an early "blunting" of the ventilatory response.

  1. Repeated acute hypoxia temporarily attenuates the ventilatory respiratory response to hypoxia in conscious newborn rats.

    PubMed

    Matsuoka, T; Yoda, T; Ushikubo, S; Matsuzawa, S; Sasano, T; Komiyama, A

    1999-07-01

    We asked whether repeated hypoxic exposures during the early neonatal periods could affect the ventilatory control, such as the lung volume-dependent ventilatory inhibition (HBR), pulmonary ventilation (VE), and CO2 production (VCO2). Within each litter of rats, one group of pups (experimental group H) was exposed to 6% O2 (30-min duration twice a day from postnatal d 1 to 4). The other group (control group C) was exposed to air. At 5 d after birth, the HBR was triggered by lung inflation via negative body surface pressure (10 cm H2O). Measurements of VE and VCO2 were done by plethysmography and the inflow-outflow CO2 difference, respectively. At 2 wk of age, VE and VCO2 measurements were repeated by the barometric technique and the inflow-outflow CO2 difference, respectively. Each conscious pup was breathing normoxia (21% O2) and then hypoxia (10% O2). Results were as follows: 1) during normoxia, HBR was stronger and both VE and VCO2 were higher in H pups than in C pups; 2) during hypoxia, the HBR of C was as in normoxia, whereas that of H was increased above the normoxic value; 3) during hypoxia, C maintained VE, whereas H decreased it; 4) in hypoxia, VCO2 was reduced significantly in both groups; 5) at 2 wk of age, VE and VCO2 did not differ between H and C during normoxia or in response to 10% hypoxia. We conclude that in rat pups, repeated hypoxic episodes can modify the HBR and, at least temporarily, reduce the VE response to hypoxia with a decrease in VCO2. The findings are in agreement with the view that repeated hypoxic exposures in the neonatal period could interfere with the development of respiratory control and could possibly be involved in the mechanisms of neonatal apnea or sudden infant death syndrome. PMID:10400145

  2. Hypoxic ventilatory responses in Tibetan residents of 4400 m compared with 3658 m.

    PubMed

    Curran, L S; Zhuang, J; Droma, T; Land, L; Moore, L G

    1995-06-01

    Lifelong Tibetan residents of 3658 m ventilate as much and have hypoxic and hypercapnic ventilatory responsiveness as least as great as acclimatized newcomers, and likely greater than lifelong North or South American high-altitude residents. To determine whether Tibetans residing at altitudes > 3658 m maintained similar levels of ventilation, hypoxic and hypercapnic ventilatory responses, we transported 20 lifelong residents of > or = 4400 m to 3658 m for comparison with 27 similarly-aged male Tibetan residents of 3658 m. At 3658 m, the 4400 m compared with the 3658 m Tibetans had similar levels of minute ventilation and arterial O2 saturation, higher respiratory quotients but lower hypoxic ventilatory responses. We conclude that Tibetan residents of > or = 4400 m ventilate as much as Tibetan residents of 3658 m despite an altitude-associated blunting of their hypoxic ventilatory responses. Thus, factors other than hypoxic ventilatory chemosensitivity are likely to be important contributors to resting ventilation among Tibetan high altitude residents.

  3. Lung Protective Ventilation (ARDSNet) versus APRV: Ventilatory Management in a Combined Model of Acute Lung and Brain Injury

    PubMed Central

    Davies, Stephen W.; Leonard, Kenji L.; Falls, Randall K.; Mageau, Ronald P.; Efird, Jimmy T.; Hollowell, Joseph P.; Trainor, Wayne E.; Kanaan, Hilal A.; Hickner, Robert C.; Sawyer, Robert G.; Poulin, Nathaniel R.; Waibel, Brett H.; Toschlog, Eric A.

    2014-01-01

    Background Concomitant lung/brain traumatic injury, results in significant morbidity and mortality. Lung protective ventilation (ARDSNet) has become the standard for managing acute respiratory distress syndrome (ARDS); however, the resulting permissive hypercapnea may compound traumatic brain injury (TBI). Airway pressure release ventilation (APRV) offers an alternative strategy for management of this patient population. APRV was hypothesized to retard the progression of acute lung/brain injury to a greater degree than ARDSNet in a swine model. Methods Yorkshire swine were randomized to ARDSNet, APRV, or sham. Ventilatory settings and pulmonary parameters, vitals, blood gases, quantitative histopathology, and cerebral microdialysis were compared between groups using chi-square, Fisher’s exact, Student’s t-test, Wilcoxon rank-sum, and mixed effects repeated measures modeling. Results 22 swine (17 male, 5 female), weighing 25±6.0kg, were randomized to APRV (n=9), ARDSNet (n=12), or sham (n=1). PaO2/FiO2 (P/F) ratio dropped significantly while intracranial pressure increased significantly for all three groups immediately following lung and brain injury. Over time, peak inspiratory pressure, mean airway pressure, and P/F ratio significantly increased, while total respiratory rate significantly decreased within the APRV group compared to the ARDSNet group. Histopathology did not show significant differences between groups in overall brain or lung tissue injury; however, cerebral microdialysis trends suggested increased ischemia within the APRV group compared to ARDSNet over time. Conclusion Previous studies have not evaluated the effects of APRV in this population. While our macroscopic parameters and histopathology did not observe a significant difference between groups, microdialysis data suggest a trend toward increased cerebral ischemia associated with APRV over time. Additional and future studies should focus on extending the time interval for observation to

  4. Acute effects of an arginine-based supplement on neuromuscular, ventilatory, and metabolic fatigue thresholds during cycle ergometry.

    PubMed

    Zak, Roksana B; Camic, Clayton L; Hill, Ethan C; Monaghan, Molly M; Kovacs, Attila J; Wright, Glenn A

    2015-04-01

    The purpose of the present study was to examine the effects of an acute dose of an arginine-based supplement on the physical working capacity at the fatigue threshold (PWCFT), lactate threshold (LT), ventilatory threshold (VT), and peak oxygen uptake during incremental cycle ergometry. This study used a double-blinded, placebo-controlled, within-subjects crossover design. Nineteen untrained men (mean age ± SD = 22.0 ± 1.7 years) were randomly assigned to ingest either the supplement (3.0 g of arginine, 300 mg of grape seed extract, and 300 mg of polyethylene glycol) or placebo (microcrystalline cellulose) and performed an incremental test on a cycle ergometer for determination of PWCFT, LT, VT, and peak oxygen uptake. Following a 1-week period, the subjects returned to the laboratory and ingested the opposite substance (either supplement or placebo) prior to completing another incremental test to be reassessed for PWCFT, LT, VT, and peak oxygen uptake. The paired-samples t tests indicated there were significant (P < 0.05) mean differences between the arginine and placebo conditions for the PWCFT (192 ± 42 vs. 168 ± 53 W, respectively) and VT (2546 ± 313 vs. 2452 ± 342 mL·min(-1)), but not the LT (135 ± 26 vs. 138 ± 22 W), absolute peak oxygen uptake (3663 ± 445 vs. 3645 ± 438 mL·min(-1)), or relative peak oxygen uptake (46.5 ± 6.0 vs. 46.2 ± 5.0 mL·kg(-1)·min(-1)). These findings suggested that the arginine-based supplement may be used on an acute basis for delaying the onset of neuromuscular fatigue (i.e., PWCFT) and improving the VT in untrained individuals.

  5. Women at altitude: ventilatory acclimatization at 4,300 m.

    PubMed

    Muza, S R; Rock, P B; Fulco, C S; Zamudio, S; Braun, B; Cymerman, A; Butterfield, G E; Moore, L G

    2001-10-01

    Women living at low altitudes or acclimatized to high altitudes have greater effective ventilation in the luteal (L) compared with follicular (F) menstrual cycle phase and compared with men. We hypothesized that ventilatory acclimatization to high altitude would occur more quickly and to a greater degree in 1) women in their L compared with women in their F menstrual cycle phase, and 2) in women compared with men. Studies were conducted on 22 eumenorrheic, unacclimatized, sea-level (SL) residents. Indexes of ventilatory acclimatization [resting ventilatory parameters, hypoxic ventilatory response, hypercapnic ventilatory response (HCVR)] were measured in 14 women in the F phase and in 8 other women in the L phase of their menstrual cycle, both at SL and again during a 12-day residence at 4,300 m. At SL only, ventilatory studies were also completed in both menstrual cycle phases in 12 subjects (i.e., within-subject comparison). In these subjects, SL alveolar ventilation (expressed as end-tidal PCO(2)) was greater in the L vs. F phase. Yet the comparison between L- and F-phase groups found similar levels of resting end-tidal PCO(2), hypoxic ventilatory response parameter A, HCVR slope, and HCVR parameter B, both at SL and 4,300 m. Moreover, these indexes of ventilatory acclimatization were not significantly different from those previously measured in men. Thus female lowlanders rapidly ascending to 4,300 m in either the L or F menstrual cycle phase have similar levels of alveolar ventilation and a time course for ventilatory acclimatization that is nearly identical to that reported in male lowlanders.

  6. Notable Australian contributions to the management of ventilatory failure of acute poliomyelitis: with special reference to the Both respirator and Dr. John A. Forbes.

    PubMed

    Trubuhovich, Ronald V

    2006-12-01

    When Australia's 1937 epidemic of poliomyelitis created an urgent need for extra ventilating machines to compensate for respiratory paralysis, Edward Both, an innovative Adelaide biomedical engineer, invented a wooden-cabinet respirator capable of being made relatively quickly in sufficient quantity. His device, here called "the Both", alleviated the problem at Adelaide's Northfield Infectious Diseases Hospital and others, and in late 1938 was introduced into England when Both was visiting there. Appreciating its merits, Lord Nuffield financed assembly-line production at the Morris motor works in Cowley, Oxford. Then, through the Nuffield Department of Anaesthetics in Oxford's Radcliffe Infirmary, he had the Both distributed Commonwealth-wide, as a gift for treating ventilatory failure in polio - especially in children. For the 1937 epidemic in Victoria, and to the design of Melbourne University's Professor of Engineering, Aubrey Burstall, nearly 200 of another wooden-cabinet respirator were ultimately built. Some were installed at the Acute Respiratory Unit of the Infectious Diseases Hospital at Fairfield, then others "all over Australia". However, by the early 1950s, the Both had replaced Fairfield Hospital's "Burstall", which had functioned as Victoria's favoured respirator since 1937. Dr John Forbes at Fairfield became the foremost Australian clinician for expertise with the Both. Before the advent of intermittent positive pressure ventilation, the Both's usefulness had seen it tried for ventilatory failure in some non-polio conditions, but uptake of that application was limited. Nonetheless, Nuffield's philanthropy with the (Nuffield-)Both ultimately furthered progress along the 20th century pathway to intensive care medicine.

  7. Correlates of obesity-related chronic ventilatory failure

    PubMed Central

    Manuel, Ari R; Hart, Nicholas; Stradling, John R

    2016-01-01

    Introduction Only a third of obese patients develop chronic ventilatory failure. This cross-sectional study assessed multiple factors potentially associated with chronic ventilatory failure. Materials/patients and methods Participants had a body mass index (BMI) >30 kg/m2, with or without chronic ventilatory failure (awake arterial partial pressure of carbon dioxide >6 kPa or base excess (BE) ≥2 mmols/L). Factors investigated were grouped into domains: (1) obesity measures, (2) pulmonary function, (3) respiratory and non-respiratory muscle strength, (4) sleep study derivatives, (5) hypoxic and hypercapnic responses, and (6) some hormonal, nutritional and inflammatory measures. Results 71 obese participants (52% male) were studied over 27 months, 52 (SD 9) years and BMI 47 (range 32–74) kg/m2. The best univariate correlates of BE from each domain were: (1) dual-energy X-ray absorptiometry measurement of visceral fat (r=+0.50, p=0.001); (2) supine forced expiratory volume in 1 s (r=−0.40, p=0.001); (3) sniff maximum pressure (r=−0.28, p=0.02); (4) mean overnight arterial oxygen saturation (r=−0.50, p<0.001); (5) ventilatory response to 15% O2 breathing (r=−0.28, p=0.02); and (6) vitamin D (r=−0.30, p=0.01). In multivariate analysis, only visceral fat and ventilatory response to hypoxia remained significant. Conclusions We have confirmed that in the obese, BMI is a poor correlate of chronic ventilatory failure, and the best independent correlates are visceral fat and hypoxic ventilatory response. Trial registration number NCT01380418. PMID:26918192

  8. Ventilatory failure, ventilator support, and ventilator weaning.

    PubMed

    Tobin, Martin J; Laghi, Franco; Jubran, Amal

    2012-10-01

    The development of acute ventilatory failure represents an inability of the respiratory control system to maintain a level of respiratory motor output to cope with the metabolic demands of the body. The level of respiratory motor output is also the main determinant of the degree of respiratory distress experienced by such patients. As ventilatory failure progresses and patient distress increases, mechanical ventilation is instituted to help the respiratory muscles cope with the heightened workload. While a patient is connected to a ventilator, a physician's ability to align the rhythm of the machine with the rhythm of the patient's respiratory centers becomes the primary determinant of the level of rest accorded to the respiratory muscles. Problems of alignment are manifested as failure to trigger, double triggering, an inflationary gas-flow that fails to match inspiratory demands, and an inflation phase that persists after a patient's respiratory centers have switched to expiration. With recovery from disorders that precipitated the initial bout of acute ventilatory failure, attempts are made to discontinue the ventilator (weaning). About 20% of weaning attempts fail, ultimately, because the respiratory controller is unable to sustain ventilation and this failure is signaled by development of rapid shallow breathing. Substantial advances in the medical management of acute ventilatory failure that requires ventilator assistance are most likely to result from research yielding novel insights into the operation of the respiratory control system. PMID:23720268

  9. Comparative human ventilatory adaptation to high altitude.

    PubMed

    Moore, L G

    2000-07-01

    Studies of ventilatory response to high altitudes have occupied an important position in respiratory physiology. This review summarizes recent studies in Tibetan high-altitude residents that collectively challenge the prior consensus that lifelong high-altitude residents ventilate less than acclimatized newcomers do as the result of acquired 'blunting' of hypoxic ventilatory responsiveness. These studies indicate that Tibetans ventilate more than Andean high-altitude natives residing at the same or similar altitudes (PET[CO(2)]) in Tibetans=29.6+/-0.8 vs. Andeans=31.0+/-1.0, P<0.0002 at approximately 4200 m), a difference which approximates the change that occurs between the time of acute hypoxic exposure to once ventilatory acclimatization has been achieved. Tibetans ventilate as much as acclimatized newcomers whereas Andeans ventilate less. However, the extent to which differences in hypoxic ventilatory response (HVR) are responsible is uncertain from existing data. Tibetans have an HVR as high as those of acclimatized newcomers whereas Andeans generally do not, but HVR is not consistently greater in comparisons of Tibetan versus Andean highland residents. Human and experimental animal studies demonstrate that inter-individual and genetic factors affect acute HVR and likely modify acclimatization and hyperventilatory response to high altitude. But the mechanisms responsible for ventilatory roll-off, hyperoxic hyperventilation, and acquired blunting of HVR are poorly understood, especially as they pertain to high-altitude residents. Developmental factors affecting neonatal arterial oxygenation are likely important and may vary between populations. Functional significance has been investigated with respect to the occurrence of chronic mountain sickness and intrauterine growth restriction for which, in both cases, low HVR seems disadvantageous. Additional studies are needed to address the various components of ventilatory control in native Tibetan, Andean and other

  10. Weaning from ventilatory support.

    PubMed

    Lessard, M R; Brochard, L J

    1996-09-01

    Resumption of spontaneous unassisted breathing after an episode of acute respiratory failure often is achieved without major difficulty. In a significant number of patients however, weaning from mechanical ventilation is a long and difficult process that markedly increases the duration of mechanical ventilation and consumes a significant fraction of critical care resources. Some criteria have been suggested to predict early and more accurately the moment the patient is ready to be separated from the ventilator. At the present time, the f/VT ratio (rapid shallow breathing index) appears to yield the best predictive power. None of these indices, however, is powerful enough to be relied on solely, and their use should be limited to that of aids to the critical care physician. The inability to sustain spontaneous ventilation usually is the consequence of an imbalance between respiratory demand and respiratory muscle capacity. Increased elastic workload, increased resistive workload, and increased VE are the main causes of excessive demand imposed on the respiratory system. Respiratory muscle pump failure usually relates to peripheral nerve dysfunction or muscular dysfunction. Left ventricular dysfunction also is an important cause of weaning failure. The usual methods of weaning from mechanical ventilation are T-piece trials with abrupt definitive discontinuation of mechanical ventilation if tolerated or with progressive intermittent trials, IMV, and PSV. All have their advantages and disadvantages, and the method of weaning per sé is not the only critical factor. Although their conclusions were different regarding the best method of weaning, however, two recent clinical trials suggest that ventilatory management has a major influence on the outcome of weaning from mechanical ventilation in difficult-to-wean patients. The global management of such patients requires a systematic approach with consideration of all factors involved in the process of separation from the

  11. Ventilatory strategies in trauma patients

    PubMed Central

    Arora, Shubhangi; Singh, Preet Mohinder; Trikha, Anjan

    2014-01-01

    Lung injury in trauma patients can occur because of direct injury to lung or due to secondary effects of injury elsewhere for example fat embolism from a long bone fracture, or due to response to a systemic insult such as; acute respiratory distress syndrome (ARDS) secondary to sepsis or transfusion related lung injury. There are certain special situations like head injury where the primary culprit is not the lung, but the brain and the ventilator strategy is aimed at preserving the brain tissue and the respiratory system takes a second place. The present article aims to delineate the strategies addressing practical problems and challenges faced by intensivists dealing with trauma patients with or without healthy lungs. The lung protective strategies along with newer trends in ventilation are discussed. Ventilatory management for specific organ system trauma are highlighted and their physiological base is presented. PMID:24550626

  12. Hypoxic ventilatory responsiveness in Tibetan compared with Han residents of 3,658 m.

    PubMed

    Zhuang, J; Droma, T; Sun, S; Janes, C; McCullough, R E; McCullough, R G; Cymerman, A; Huang, S Y; Reeves, J T; Moore, L G

    1993-01-01

    Lifelong high-altitude residents of North and South America acquire blunted hypoxic ventilatory responses and exhibit decreased ventilation compared with acclimatized newcomers. The ventilatory characteristics of Himalayan high-altitude residents are of interest in the light of their reportedly lower hemoglobin levels and legendary exercise performance. Until recently, Sherpas have been the only Himalayan population available for study. To determine whether Tibetans exhibited levels of ventilation and hypoxic ventilatory drives that were as great as acclimatized newcomers, we compared 27 lifelong Tibetan residents of Lhasa, Tibet, China (3,658 m) with 30 acclimatized Han ("Chinese") newcomers matched for age, body size, and extent of exercise training. During room air breathing, minute ventilation was greater in the Tibetan than in the Han young men because of an increased respiratory frequency, but arterial O2 saturation and end-tidal PCO2 did not differ, indicating similar levels of effective alveolar ventilation. The Tibetan subjects had higher hypoxic ventilatory response shape parameter A values and hypercapnic ventilatory responsiveness than the Han subjects. Among the Han subjects, duration of high-altitude residence correlated with the degree of blunting of the hypoxic ventilatory drive. Paradoxically, hyperoxia (inspired O2 fraction 0.70) increased minute ventilation and decreased end-tidal PCO2 in the Tibetan but not in the Han men. We concluded that lifelong Tibetan residents of high altitude neither hypoventilated nor exhibited blunted hypoxic ventilatory responses compared with acclimatized Han newcomers, suggesting that the effects of lifelong high-altitude residence on ventilation and ventilatory response to hypoxia differ in Tibetan compared with other high-altitude populations.

  13. Adenosine receptors mediate the hypoxic ventilatory response but not the hypoxic metabolic response in the naked mole rat during acute hypoxia.

    PubMed

    Pamenter, Matthew E; Dzal, Yvonne A; Milsom, William K

    2015-02-01

    Naked mole rats are the most hypoxia-tolerant mammals identified; however, the mechanisms underlying this tolerance are poorly understood. Using whole-animal plethysmography and open-flow respirometry, we examined the hypoxic metabolic response (HMR), hypoxic ventilatory response (HVR) and hypoxic thermal response in awake, freely behaving naked mole rats exposed to 7% O₂ for 1 h. Metabolic rate and ventilation each reversibly decreased 70% in hypoxia (from 39.6 ± 2.9 to 12.1 ± 0.3 ml O₂ min(-1) kg(-1), and 1412 ± 244 to 417 ± 62 ml min(-1) kg(-1), respectively; p < 0.05), whereas body temperature was unchanged and animals remained awake and active. Subcutaneous injection of the general adenosine receptor antagonist aminophylline (AMP; 100 mg kg(-1), in saline), but not control saline injections, prevented the HVR but had no effect on the HMR. As a result, AMP-treated naked mole rats exhibited extreme hyperventilation in hypoxia. These animals were also less tolerant to hypoxia, and in some cases hypoxia was lethal following AMP injection. We conclude that in naked mole rats (i) hypoxia tolerance is partially dependent on profound hypoxic metabolic and ventilatory responses, which are equal in magnitude but occur independently of thermal changes in hypoxia, and (ii) adenosine receptors mediate the HVR but not the HMR.

  14. Adenosine receptors mediate the hypoxic ventilatory response but not the hypoxic metabolic response in the naked mole rat during acute hypoxia

    PubMed Central

    Pamenter, Matthew E.; Dzal, Yvonne A.; Milsom, William K.

    2015-01-01

    Naked mole rats are the most hypoxia-tolerant mammals identified; however, the mechanisms underlying this tolerance are poorly understood. Using whole-animal plethysmography and open-flow respirometry, we examined the hypoxic metabolic response (HMR), hypoxic ventilatory response (HVR) and hypoxic thermal response in awake, freely behaving naked mole rats exposed to 7% O2 for 1 h. Metabolic rate and ventilation each reversibly decreased 70% in hypoxia (from 39.6 ± 2.9 to 12.1 ± 0.3 ml O2 min−1 kg−1, and 1412 ± 244 to 417 ± 62 ml min−1 kg−1, respectively; p < 0.05), whereas body temperature was unchanged and animals remained awake and active. Subcutaneous injection of the general adenosine receptor antagonist aminophylline (AMP; 100 mg kg−1, in saline), but not control saline injections, prevented the HVR but had no effect on the HMR. As a result, AMP-treated naked mole rats exhibited extreme hyperventilation in hypoxia. These animals were also less tolerant to hypoxia, and in some cases hypoxia was lethal following AMP injection. We conclude that in naked mole rats (i) hypoxia tolerance is partially dependent on profound hypoxic metabolic and ventilatory responses, which are equal in magnitude but occur independently of thermal changes in hypoxia, and (ii) adenosine receptors mediate the HVR but not the HMR. PMID:25520355

  15. The successful treatment of hypercapnic respiratory failure with oral modafinil

    PubMed Central

    Parnell, Helen; Quirke, Ginny; Farmer, Sally; Adeyemo, Sumbo; Varney, Veronica

    2014-01-01

    Hypercapnic respiratory failure is common in advanced chronic obstructive pulmonary disease and is usually treated by nasal ventilation. Not all patients requiring such ventilation can tolerate it, with anxiety and phobia influencing their reaction, along with treatment failure. We report the case histories of six patients with hypercapnic respiratory failure who were at risk of death due to refusal of nasal ventilation or its failure despite ongoing treatment. We report their improvement with oral modafinil 200 mg tablets used as a respiratory stimulant, which led to discharge, improved arterial blood gases, and offset further admissions with hypercapnic respiratory failure. This drug is licensed for narcolepsy and is said to stimulate the respiratory system via the central nervous system. Its use in respiratory failure is an unlicensed indication, and there are no case reports or studies of such use in the literature. Its respiratory stimulant effects appear better than those with protriptyline, which was a drug previously used until its production was discontinued. Our findings suggest that a study of modafinil in hypercapnic respiratory failure would be warranted, especially for patients with treatment failure or intolerance to nasal ventilation. This may offer a way of shortening hospital stay, improving outcome and quality of life, and reducing death and readmissions. PMID:24812505

  16. Psychophysical Differences in Ventilatory Awareness and Breathlessness between Athletes and Sedentary Individuals

    PubMed Central

    Faull, Olivia K.; Cox, Pete J.; Pattinson, Kyle T. S.

    2016-01-01

    Purpose: Breathlessness is a complex set of symptoms that are comprised of both sensory and affective (emotional) dimensions. While ventilation is now understood to be a potential limiter to performance in highly-trained individuals, the contribution of breathlessness-anxiety in those nearing maximal ventilation during intense exercise has not yet been considered as a limiter to performance. Methods: In this study, we compared the physiology and psychology of breathlessness in 20 endurance athletes with 20 untrained age- and sex-matched sedentary controls. Subjects completed baseline spirometry and anxiety questionnaires, an incremental exercise test to exhaustion and a steady-state hypercapnic ventilatory response test, with concurrent measures of breathlessness intensity and breathlessness-anxiety. Results: Compared with sedentary subjects, athletes reported equivalent breathlessness intensity but greater breathlessness-anxiety at maximal exercise (athletes vs. sedentary (mean ± SD): breathlessness intensity (0–100%) 80.7 (22.7) vs. 72.5 (17.2), p = 0.21; breathlessness-anxiety (0–100%), 45.3 (36.3) vs. 22.3 (20.0), p = 0.02). Athletes operated at higher proportions of their maximal ventilatory capacity (MVV) (athletes vs. sedentary (mean ventilation ± SD; % MVV): 101.6 (27.2) vs. 73.7 (30.1), p = 0.003). In the athletes there was a positive linear correlation between ventilation and breathlessness score during the hypercapnic challenge that was not observed in the sedentary controls. Conclusion: The results of this study indicate that whilst operating at high proportions of maximal ventilation, breathlessness-anxiety becomes increasingly prominent in athletes. Our results suggest that ventilatory perception pathways may be a target for improved athletic performance in some individuals. PMID:27378940

  17. The Effects of Lung Protective Ventilation or Hypercapnic Acidosis on Gas Exchange and Lung Injury in Surfactant Deficient Rabbits

    PubMed Central

    Hummler, Helmut D.; Banke, Katharina; Wolfson, Marla R.; Buonocore, Giuseppe; Ebsen, Michael; Bernhard, Wolfgang; Tsikas, Dimitrios; Fuchs, Hans

    2016-01-01

    Background Permissive hypercapnia has been shown to reduce lung injury in subjects with surfactant deficiency. Experimental studies suggest that hypercapnic acidosis by itself rather than decreased tidal volume may be a key protective factor. Objectives To study the differential effects of a lung protective ventilatory strategy or hypercapnic acidosis on gas exchange, hemodynamics and lung injury in an animal model of surfactant deficiency. Methods 30 anesthetized, surfactant-depleted rabbits were mechanically ventilated (FiO2 = 0.8, PEEP = 7cmH2O) and randomized into three groups: Normoventilation-Normocapnia (NN)-group: tidal volume (Vt) = 7.5 ml/kg, target PaCO2 = 40 mmHg; Normoventilation-Hypercapnia (NH)-group: Vt = 7.5 ml/kg, target PaCO2 = 80 mmHg by increasing FiCO2; and a Hypoventilation-Hypercapnia (HH)-group: Vt = 4.5 ml/kg, target PaCO2 = 80 mmHg. Plasma lactate and interleukin (IL)-8 were measured every 2 h. Animals were sacrificed after 6 h to perform bronchoalveolar lavage (BAL), to measure lung wet-to-dry weight, lung tissue IL-8, and to obtain lung histology. Results PaO2 was significantly higher in the HH-group compared to the NN-group (p<0.05), with values of the NH-group between the HH- and NN-groups. Other markers of lung injury (wet-dry-weight, BAL-Protein, histology-score, plasma-IL-8 and lung tissue IL-8) resulted in significantly lower values for the HH-group compared to the NN-group and trends for the NH-group towards lower values compared to the NN-group. Lactate was significantly lower in both hypercapnia groups compared to the NN-group. Conclusion Whereas hypercapnic acidosis may have some beneficial effects, a significant effect on lung injury and systemic inflammatory response is dependent upon a lower tidal volume rather than resultant arterial CO2 tensions and pH alone. PMID:26840779

  18. Ventilatory adaptation to hypoxia occurs in serotonin-depleted rats.

    PubMed

    Olson, E B

    1987-08-01

    To test the hypothesis that serotonin mediated respiratory activity is involved in ventilatory adaptation to hypoxia, rats were treated with parachlorophenylalanine (PCPA), a potent, long-acting inhibitor of tryptophan hydroxylase, the rate-limiting enzyme in the biosynthesis of serotonin. In normoxia, a single, intraperitoneal injection of 300 mg PCPA/kg body weight decreased the Paco2 from a control level at 39.1 +/- 0.6 Torr (mean +/- 95% confidence limits) to 34.0 +/- 0.6 Torr measured during a period from 1 to 48 h following PCPA treatment. This PCPA-produced hyperventilation corresponds to an increase of 3.7 +/- 0.5 in the VA (BTPS)/Vco2 (STPD) ratio. Hyperventilation during ventilatory adaptation to hypoxia (PIO2 approximately equal to 90 Torr) was superimposed in an additive fashion on the underlying hyperventilation due to PCPA pretreatment. Specifically, PCPA pretreatment caused an average 3.5 +/- 1.2 increase in the VA/VCO2 ratio determined in acute (1 h) hypoxia, chronic (24 h) hypoxia and acute return to normoxia following chronic hypoxia. Since ventilatory adaptation to hypoxia occurred in rats treated with PCPA, the prolonged, serotonin mediated respiratory activity described by Millhorn et al. (1980b) is probably not important in ventilatory acclimatization to - or deacclimatization from - hypoxia. PMID:2957766

  19. The state of cerebral hemodynamics in conditions of prolonged adaptation to hypercapnic hypoxia.

    PubMed

    Kulikov, V P; Bespalov, A G; Yakushev, N N

    2009-03-01

    Intermittent hypercapnic hypoxia was accompanied by increases in cerebral vascular resistance, decreases in the reactivity of cerebral vessels to hypercapnia, and increases in the collateral reserve and rate of autoregulation of brain blood flow. These changes were an important component of the mechanism increasing the tolerance of the brain to ischemia in response to training with hypercapnic hypoxia. PMID:19234804

  20. Depressed Hypoxic and Hypercapnic Ventilatory Responses at Early Stage of Lethal Avian Influenza A Virus Infection in Mice

    PubMed Central

    Pollock, Zemmie; Harrod, Kevin S.; Xu, Fadi

    2016-01-01

    H5N1 virus infection results in ~60% mortality in patients primarily due to respiratory failure, but the underlying causes of mortality are unclear. The goal of this study is to reveal respiratory disorders occurring at the early stage of infection that may be responsible for subsequent respiratory failure and death. BALB/c mice were intranasally infected with one of two H5N1 virus strains: HK483 (lethal) or HK486 (non-lethal) virus. Pulmonary ventilation and the responses to hypoxia (HVR; 7% O2 for 3 min) and hypercapnia (HCVR; 7% CO2 for 5 min) were measured daily at 2 days prior and 1, 2, and 3 days postinfection (dpi) and compared to mortality typically by 8 dpi. At 1, 2, and 3 dpi, immunoreactivities (IR) of substance P (SP-IR) in the nodose ganglion or tyrosine hydroxylase (TH-IR) in the carotid body coupled with the nucleoprotein of influenza A (NP-IR) was examined in some mice, while arterial blood was collected in others. Our results showed that at 2 and 3 dpi: 1) both viral infections failed to alter body temperature and weight, V˙CO2, or induce viremia while producing similarly high lung viral titers; 2) HK483, but not HK486, virus induced tachypnea and depressed HVR and HCVR without changes in arterial blood pH and gases; and 3) only HK483 virus led to NP-IR in vagal SP-IR neurons, but not in the carotid body, and increased density of vagal SP-IR neurons. In addition, all HK483, rather than HK486, mice died at 6 to 8 dpi and the earlier death was correlated with more severe depression of HVR and HCVR. Our data suggest that tachypnea and depressed HVR/HCVR occur at the early stage of lethal H5N1 viral infection associated with viral replication and increased SP-IR density in vagal neurons, which may contribute to the respiratory failure and death. PMID:26808681

  1. [Ventilatory strategy for ARDS].

    PubMed

    Yoshida, Takeshi; Takegawa, Ryousuke; Ogura, Hiroshi

    2016-02-01

    Fifteen years have passed since lung protective strategy to the patients with acute respiratory distress syndrome (ARDS) established. Recently, the new Berlin Definition of ARDS has been developed and this classified ARDS into three stages (mild, moderate, and severe ARDS), depending on the PaO2/FiO2. After this new definition of ARDS, each treatment to the patients with ARDS should be considered, depending on the severity of lung injury, such as prone position to the patients with severe ARDS, muscle paralysis to the patients with severe ARDS. In this review article, we review the history of lung protective strategy and ARDS definition, discuss the novel physiological approaches to minimizing ventilator-induced lung injury, and highlight a numbers of experimental/clinical studies to support these concepts. PMID:26915253

  2. Ventilatory response to transient hypoxia in O2 divers.

    PubMed

    Melamed, Y; Kerem, D

    1988-05-01

    This study addresses the question of whether repeated acute exposure to hyperbaric oxygen, such as encountered in O2 diving, affects the peripheral oxygen chemosensors. Groups of nondivers, active O2 divers, and ex-O2 divers, as well as active air scuba divers, were given 1 or both of 2 tests that measure the ventilatory response to transient hypoxia. Results showed that all groups of divers have a mean response similar to or higher than that of nondivers as well as that of normal subjects, as reported in the literature. A repeat test on 10 diving candidates before and after 200 h of accrued O2 diving also did not show an impairment in the hypoxic ventilatory response. Oxygen diving within the established depth and time limits does not seem to cause cumulative damage to the peripheral O2 chemosensors.

  3. Attenuated ventilatory responses to hypercapnia and hypoxia in assisted breath-hold drivers (Funado).

    PubMed

    Masuda, Y; Yoshida, A; Hayashi, F; Sasaki, K; Honda, Y

    1982-01-01

    The steady-state ventilatory responses to hypercapnia and hypoxia in 7 assisted breath-hold divers (Funado) were compared with those in 7 normal sedentary controls. Ventilatory response to hypercapnia was measured from the slope of the hyperoxic VN-PETCO2 line, where VN was normalized minute ventilation using the allometric coefficient and PETCO2 end-Tidal PCO2. The slope of this line in the Funado (1.48 +/- 0.54 liters . min-1 . Torr-1) was significantly less than in the control (2.70 +/- 1.08 liters . min-1 . Torr-1) (p less than 0.025). On the other hand, hypoxic sensitivity estimated by hyperbolic and exponential mathematical equations was not found to be significantly different between the two groups, although estimated increments in ventilation using the hyperbolic equation exhibited significantly lower response in the Funado than in the control only when PETO2 decreased lower than 50 Torr (p less than 0.05). These findings in the Funado were different from our previous observations obtained in unassisted breath-hold divers (Kachido), in whom no obvious attenuations in CO2 sensitivity were seen. This difference was assumed to be derived from more hypercapnic and hypoxic conditions produced in the Funado than in the Kachido during diving activities.

  4. The effects of large-dose flumazenil on midazolam-induced ventilatory depression.

    PubMed

    Flögel, C M; Ward, D S; Wada, D R; Ritter, J W

    1993-12-01

    Flumazenil, a benzodiazepine antagonist, clearly reverses midazolam-induced sedation; reversal of ventilatory depression has not been as well demonstrated. Thirty-two subjects completed this randomized, double-blind, placebo-controlled study investigating the dose-response relationship and duration of flumazenil's effects on ventilatory depression and hypnosis induced by a continuous midazolam infusion. A computer-controlled infusion of midazolam was used to titrate the predicted midazolam plasma concentration to a level at which subjects were unresponsive to verbal commands and then to maintain that concentration. Measurements of ventilation and hypnosis were repeated at predetermined intervals: before midazolam administration, before test drug (flumazenil [1, 3, or 10 mg] or placebo), and 5, 30, 60, 120, and 180 min after test drug administration. Ventilation and tidal volume were measured during an isocapnic hyperoxia clamp at a PETCO2 of 46 mm Hg (VE46 and VT46, respectively). A pseudo-rebreathing technique was used to measure the hypercapnic ventilatory response (HCVR) slope and ventilation intercept at a PETCO2 of 58 mm Hg (VE58). Midazolam reduced VE46, VT46, and VE58, as well as hypnosis scores, in all test drug groups. The reduction in HCVR slope, however, was significant only when all 32 subjects were considered in aggregate. All three doses of flumazenil reversed hypnosis and also reversed the reduction in VE46 and VT46 within 5 min. The reduction in VE58, however, was reversed less consistently. Flumazenil's effect on VE46 and VT46 lasted at least 30 min after 1 mg and at least 60 min after 3 mg, paralleling the effect of these doses on hypnosis.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. Always Consider the Possibility of Opioid Induced Respiratory Depression in Patients Presenting with Hypercapnic Respiratory Failure Who Fail to Improve as Expected with Appropriate Therapy

    PubMed Central

    Steynor, Martin; MacDuff, Andrew

    2015-01-01

    Hypercapnic respiratory failure is a frequently encountered medical emergency. Two common causes are acute exacerbations of chronic obstructive pulmonary disease (COPD) and as a side effect of opioids. The two causes may coexist leading to diagnostic confusion and consequent delay in optimal management. We report a case of what was initially thought to be an exacerbation of COPD. The patient failed to improve with treatment as expected which led to the empirical administration of naloxone resulting in a dramatic reversal of her respiratory failure. The patient was subsequently discovered to be taking regular dihydrocodeine for chronic back pain. PMID:25893118

  6. Associative conditioning with leg cycling and inspiratory resistance enhances the early exercise ventilatory response in humans.

    PubMed

    Turner, Duncan; Stewart, Jamie D

    2004-12-01

    Repeated trials of hypercapnic exercise [deltaPET CO2 = 7 (1) mmHg] augment the increase in inspired minute ventilation and tidal volume (V(T)) in the early phase of subsequent trials of unencumbered exercise alone. The increase in V(T) in the first 20 s of exercise was correlated to the increase in V(T) evoked during hypercapnic exercise trials, suggesting that the evoked increase in V(T) during conditioning may be a factor in mediating associative conditioning. To test this hypothesis, inspiratory resistive loading (IRL) was employed to evoke an increase in V(T) [deltaV(T) = 0.4 (0.1) I(BTPS)] during conditioning exercise trials [IRL + EX; deltaP(ET)CO2 = 2 (l) mmHg]. IRL + EX associative conditioning elicited a significant augmentation of the early minute ventilation (+46%) and V(T) (+100%) responses to subsequent unencumbered exercise. The latter was correlated to the evoked increase in V(T) during associative conditioning with IRL + EX. The results support the hypothesis that an evoked increase in V(T) during associative conditioning could be a factor in eliciting long-term modulation of minute ventilation in subsequent unencumbered exercise. The results further indicated that the modulation of ventilation early in exercise is not due to sensitisation to repeated trials of either IRL or exercise alone. Associative conditioning may shape the ventilatory response to exercise through a process of motor learning. Data are presented as mean (SEM) unless otherwise stated.

  7. Evaluation of ventilatory therapy for acid aspiration.

    PubMed

    Flint, L; Gosdin, G; Carrico, C J

    1975-10-01

    Aspiration of hydrochloric acid in experimental animals results in severe, progressive hypoxia which is due to intrapulmonary shunting and depressed cardiac output. This preparation is useful therefore in studying the therapy of hypoxia. Mongrel dogs were subjected to acid aspiration and the effects of several ventilatory patterns on intrapulmonary shunt fractions and lung water accumulation observed. The combination of large tidal volumes (30 c.c. per kilogram) with positive end-expiratory pressure was effective in preventing intrapulmonary shunting and other ventilatory patterns were ineffective. Pulmonary edema uniformly followed acid aspiration and was not affected by ventilatory therapy. When ventilatory therapy was delayed for 4 hours, the progression of shunting apparently was limited, but the existing shunt was not reduced.

  8. [Management of acute exacerbations of COPD].

    PubMed

    Rabbat, A; Guetta, A; Lorut, C; Lefebvre, A; Roche, N; Huchon, G

    2010-10-01

    Exacerbations of COPD are common and cause a considerable burden to the patient and the healthcare system. To optimize the hospital care of patients with exacerbations of COPD, clinicians should be aware of some key points: management of exacerbations is broadly based on clinical features and severity. Initial clinical evaluation is crucial to define those patients requiring hospital admission and those who could be managed as outpatients. In hospitalized patients, the appropriate level of care should be determined by the initial severity and response to initial medical treatment. Medical treatment should follow recent recommendations, including rest, titrated oxygen therapy, inhaled or nebulized short-acting bronchodilators (Beta2-agonists and anticholinergic agents), DVT prevention with LMWH, steroids in most severely ill patients, unless there are contraindications and antibiotics in the case of a clear bacterial infectious aetiology. Severe exacerbations may lead to acute hypercapnic respiratory failure. Unless contraindicated, non-invasive ventilation (NIV) should be the first line ventilatory support for these patients. NIV should be commenced early, before severe acidosis ensues, to avoid the need for endotracheal intubation and to reduce mortality and treatment failures. Several randomised controlled clinical trials support the use of NIV in the management of acute exacerbations of COPD, demonstrating a decreased need for mechanical ventilation and an improved survival. In most severe cases, NIV should be provided in ICU. Although it has been shown that for less severe patients (with pH values>7.30), NIV can be administered safely and effectively on general medical wards, a lead respiratory consultant and trained nurses are mandatory. Mechanical ventilation through an endotracheal tube should be considered when patients have contraindications to the use of NIV or fail to improve on NIV. The duration of mechanical ventilation should be shortened as much as

  9. [Mechanical ventilation in chronic ventilatory insufficiency].

    PubMed

    Schucher, B; Magnussen, H

    2007-10-01

    Mechanical ventilation has become an important treatment option in chronic ventilatory failure. There are different diseases which lead to ventilatory failure and to home mechanical ventilation (HMV). A primary loss of in- and expiratory muscle strength is the reason for respiratory deterioration in neuromuscular disease. In most of these diseases ventilatory failure develops because of the progressive character of muscular damage. Initially, ventilatory failure can be found during night-time. In the case of hypercapnia at daytime, life expectancy is strongly reduced, especially in amyotrophic lateral sclerosis and Duchenne muscular dystrophy. HMV leads to a prolongation of life and to an increase in quality of life, if bulbar involvement is not severe. Impressive clinical improvements under HMV have been found in restrictive disorders of the rib cage like kyphoscoliosis or posttuberculosis sequelae, with an increase of quality of life, walking distance and a decrease in pulmonary hypertension. Only few data are published about long-term results of HMV in Obesity Hypoventilation. In terms of retrospective analyses of clinical data HMV seems to improve survival in this population. Some patients only need CPAP treatment, but most patients have to be treated with ventilatory support. The application of HMV in patients with chronic ventilatory failure due to chronic obstructive pulmonary disease (COPD) is growing, but there are controversial results in randomised clinical trials. Analysis of these data suggest better results of HMV in patients with severe hypercapnia, with the application of higher effective ventilatory pressure and a ventilator mode with a significant reduction in the work of breathing. Under such conditions HMV leads to a reduction of hypercapnia, an improvement in sleep quality, walking distance and quality of life, but until now there is no evidence in reduction of mortality in COPD. PMID:17620231

  10. Time domains of the hypoxic ventilatory response in ectothermic vertebrates.

    PubMed

    Porteus, Cosima; Hedrick, Michael S; Hicks, James W; Wang, Tobias; Milsom, William K

    2011-04-01

    Over a decade has passed since Powell et al. (Respir Physiol 112:123-134, 1998) described and defined the time domains of the hypoxic ventilatory response (HVR) in adult mammals. These time domains, however, have yet to receive much attention in other vertebrate groups. The initial, acute HVR of fish, amphibians and reptiles serves to minimize the imbalance between oxygen supply and demand. If the hypoxia is sustained, a suite of secondary adjustments occur giving rise to a more long-term balance (acclimatization) that allows the behaviors of normal life. These secondary responses can change over time as a function of the nature of the stimulus (the pattern and intensity of the hypoxic exposure). To add to the complexity of this process, hypoxia can also lead to metabolic suppression (the hypoxic metabolic response) and the magnitude of this is also time dependent. Unlike the original review of Powell et al. (Respir Physiol 112:123-134, 1998) that only considered the HVR in adult animals, we also consider relevant developmental time points where information is available. Finally, in amphibians and reptiles with incompletely divided hearts the magnitude of the ventilatory response will be modulated by hypoxia-induced changes in intra-cardiac shunting that also improve the match between O(2) supply and demand, and these too change in a time-dependent fashion. While the current literature on this topic is reviewed here, it is noted that this area has received little attention. We attempt to redefine time domains in a more 'holistic' fashion that better accommodates research on ectotherms. If we are to distinguish between the genetic, developmental and environmental influences underlying the various ventilatory responses to hypoxia, however, we must design future experiments with time domains in mind. PMID:21312038

  11. Breathing pattern and ventilatory chemosensitivity of the 1-day old Muscovy duck (Cairina moschata) in relation to its metabolic demands.

    PubMed

    Mortola, Jacopo P; Toro-Velasquez, Paula Andrea

    2014-01-01

    Adult birds have a ventilatory equivalent (pulmonary ventilation-oxygen consumption ratio, V˙ E/ [Formula: see text] ) lower than mammals because of the superior gas exchange efficiency of their respiratory apparatus. In particular, adult Muscovy ducks (Cairina moschata) have been reported to have an extraordinary low ventilatory equivalent (~14mL STPD·mL BTPS(-1)). We asked if similar high efficiency was already apparent in duck hatchlings. Breathing pattern and V˙E were measured by the barometric technique and [Formula: see text] by an open-flow methodology in 1-day old Muscovy duck hatchlings (N=21); same measurements were performed on chicken hatchlings (N=21) for purpose of comparison. During air breathing V˙E/ [Formula: see text] was slightly, yet significantly, lower in ducklings (20.8) than in chicks (25.3), mostly because of a lower breathing frequency (f). The hatchlings of both species (N=14 per group) responded to inspired hypoxia (15 or 10% O2) or hypercapnia (2 or 4% CO2) with a clear hyperventilation; however, in ducklings the hypercapnic hyperventilation was smaller than in chicks because of a smaller increase in tidal volume and lower f. We conclude that duck and chicken hatchlings just a few hours old have the high ventilatory efficiency typical of birds, although possibly not as high as their adults. The low f and blunted V˙E response to hypercapnia of the newborn duck could be related to the aquatic habitat of the species. In such a case, it would mean that these characteristics are genetic traits, the phenotypic expression of which does not require diving experience. PMID:24055760

  12. Onset and early development of hypoxic ventilatory responses and branchial neuroepithelial cells in Xenopus laevis.

    PubMed

    Pan, Tien-Chien F; Burggren, Warren W

    2010-12-01

    Onset and ontogeny of the O₂ chemoreceptive control of ventilation was investigated in Xenopus laevis. The density and size of branchial serotonin-immunoreactive neuroepithelial cells (5-HT-IR NECs) were also determined using confocal immunofluorescent microscopy. Larvae started gill ventilation at 3 days post-fertilization (dpf), and, at this early stage, acute hypoxic exposure produced an increase in frequency from 28 ± 4 to 60 ± 2 beats x min⁻¹. Concurrent with the onset of ventilatory responses, 5-HT-IR NECs appeared in the gill filament bud. Lung ventilation began at 5 dpf and exhibited a 3-fold increase in frequency during acute hypoxia. At 10 dpf, gill ventilatory sensitivity to hypoxia increased, as did NEC density, from 15 ± 1 (5 dpf) to 29 ± 2 (10 dpf) cells x mm of filament⁻¹. Unlike ventilation frequency, gill ventilation amplitude and lung expired volume were unaltered by acute hypoxia. Chronic exposure to moderate hypoxia, at a P(O₂) of 110 mmHg, attenuated acute responses to moderate hypoxia at 10 and 14 dpf but had no effect at more severe hypoxia or at other stages. Chronic hypoxia also stimulated 5-HT-IR NECs growth at 21 dpf. Collectively, larvae at 5 dpf exhibited strong O₂-driven gill and lung ventilatory responses, and between 10 and 21 dpf, the early hypoxic responses can be shaped by the ambient P(O₂).

  13. 20 CFR 410.430 - Ventilatory studies.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false Ventilatory studies. 410.430 Section 410.430 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL COAL MINE HEALTH AND SAFETY ACT OF 1969, TITLE IV-BLACK LUNG BENEFITS (1969- ) Total Disability or Death Due to Pneumoconiosis § 410.430...

  14. 20 CFR 410.430 - Ventilatory studies.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Ventilatory studies. 410.430 Section 410.430 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL COAL MINE HEALTH AND SAFETY ACT OF 1969, TITLE IV-BLACK LUNG BENEFITS (1969- ) Total Disability or Death Due to Pneumoconiosis § 410.430...

  15. [The role of adenosine Al receptors and mitochondrial K+ATP channels in the mechanism of increasing the resistance to acute hypoxia in the combined effects of hypoxia and hypercapnia].

    PubMed

    Tregub, P P; Kulikov, V P; Stepanova, L A; Zabrodina, A S; Nagibaeva, M E

    2014-01-01

    We studied the role of the role of mitoK+ATp channels and Al-adenosine receptor in the mechanism of increasing the resistance to acute hypoxia after hypoxic, hypercapnic and hypercapnic-hypoxic preconditioning. It is shown that mitochondrial ATP-sensitive potassium channels and Al-adenosine receptors, an important mechanism of preconditioning have a high value to increase the resistance to acute hypoxia/ischemia in the combined effect of hypoxia and hypercapnia. However, with regard to the adenosine receptor, this mechanism is realized without the participation hypercapnic component, which apparently starts neuroprotection without activation of the adenosine Al receptors. PMID:25980226

  16. Ventilatory drive during face immersion in man.

    PubMed Central

    Mukhtar, M R; Patrick, J M

    1986-01-01

    Four series of experiments have been performed in normal subjects to determine whether face immersion gives rise to a reduction in ventilatory drive. Such a response might be advantageous, like the cardiovascular components of the 'diving response', in prolonging breath-hold diving. In the first series, ventilatory drive was measured indirectly as the maximal voluntary breath-holding time, starting each breath-hold at the same alveolar partial pressures and at the same lung volume. When the face was immersed in cold water, breath-holding times were increased by 14%. The breaking point occurred at a higher alveolar PCO2 and the rate of rise of PCO2 was not affected. Control immersions in warm water had no effect. In the second and third series, subjects lay prone and breathed either air or 5% CO2 through a valve in the bottom of a bowl. Minute ventilation was measured before, during and after 5 min of face immersion in cold water. Transient hypoventilations of 13% and 10% respectively were seen, accompanied by small rises in alveolar PCO2. In control experiments, immersion of the forearm in cold water produced the opposite responses. In the fourth series, a cold wet pack was applied to the face during moderate steady-state exercise. A small irregular hypoventilation was seen, but not in control experiments when a warm pack was applied. Face temperatures fell by about 10 degrees C in these experiments. No material changes were found in the temperatures of the inspired air or of the aural canal. It is concluded that face immersion in cold water causes a modest reduction in ventilatory drive in man. This appears to be a component of the 'diving response'. PMID:3083097

  17. Intermittent hypercapnia induces long-lasting ventilatory plasticity to enhance CO2 responsiveness to overcome dysfunction

    NASA Astrophysics Data System (ADS)

    Mosher, Bryan Patrick

    The ability of the brain to detect (central CO2 chemosensitivity) and respond to (central CO2 chemoresponsiveness) changes in tissue CO2/pH, is a homeostatic process essential for mammalian life. Dysfunction of the serotonin (5-HT) mechanisms compromises ventilatory CO 2 chemosensitivity/responsiveness and may enhance vulnerability to pathologies such as the Sudden Infant Death Syndrome (SIDS). The laboratory of Dr. Michael Harris has shown medullary raphe contributions to central chemosensitivity involving both 5-HT- and gamma-aminobutyric acid (GABA)-mediated mechanisms. I tested the hypothesis that postnatal exposure to mild intermittent hypercapnia (IHc) induces respiratory plasticity, due in part to strengthening of bicuculline- and saclofen-sensitive mechanisms (GABAA and GABAB receptor antagonists respectively). Rats were exposed to IHc-pretreatment (8 cycles of 5 % CO2) for 5 days beginning at postnatal day 12 (P12). I subsequently assessed CO2 responsiveness using an in situ perfused brainstem preparation. Hypercapnic responses were determined with and without pharmacological manipulation. In addition, IHc-pretreatment effectiveness was tested for its ability to overcome dysfunction in the CO2 responsiveness induced by a dietary tryptophan restriction. This dysfunctional CO2 responsiveness has been suggested to arise from a chronic, partial 5-HT reduction imparted by the dietary restriction. Results show IHc-pretreatment induced plasticity sufficient for CO2 responsiveness despite removal of otherwise critical ketanserin-sensitive mechanisms. CO2 responsiveness following IHc-pretreatment was absent if ketanserin was combined with bicuculline and saclofen, indicating that the plasticity was dependent upon bicuculline- and saclofen-sensitive mechanisms. IHc--induced plasticity was also capable of overcoming the ventilatory defects associated with maternal dietary restriction. Duration of IHc-induced plasticity was also investigated and found to last far into

  18. Mass Law Predicts Hyperbolic Hypoxic Ventilatory Response

    NASA Astrophysics Data System (ADS)

    Severinghaus, John W.

    The hyperbolic hypoxic ventilatory response vs PaO2, HVRp, is interpreted as relecting a mass hyperbolic relationship of cytochrome PcO2 to cytochrome potential Ec, offset 32 torr by the constant diffusion gradient between arterial blood and cytochrome in CB at its constant metabolic rate dot VO_2 . Ec is taken to be a linear function of redox reduction and CB ventilatory drive. As Ec rises in hypoxia, the absolute potentials of each step in the citric acid cycle rises equally while the potential drop across each step remains constant because flux rate remains constant. A hypothetic HVRs ( dot VE vs SaO2) response curve computed from these assumptions is strikingly non linear. A hypothetic HVRp calculated from an assumed linear HVRs cannot be fit to the observed hyperbolic increase of ventilation in response to isocapnic hypoxia at PO2 less than 40 torr. The incompatibility of these results suggest that in future studies HVRs will not be found to be linear, especially below 80% SaO2 and HVRp will fail to be accurately hyperbolic.

  19. Ventilatory Dysfunction in Parkinson’s Disease

    PubMed Central

    Baille, Guillaume; De Jesus, Anna Maria; Perez, Thierry; Devos, David; Dujardin, Kathy; Charley, Christelle Monaca; Defebvre, Luc; Moreau, Caroline

    2016-01-01

    In contrast to some other neurodegenerative diseases, little is known about ventilatory dysfunction in Parkinson’s disease (PD). To assess the spectrum of ventilation disorders in PD, we searched for and reviewed studies of dyspnea, lung volumes, respiratory muscle function, sleep breathing disorders and the response to hypoxemia in PD. Among the studies, we identified some limitations: (i) small study populations (mainly composed of patients with advanced PD), (ii) the absence of long-term follow-up and (iii) the absence of functional evaluations under “off-drug” conditions. Although there are many reports of abnormal spirometry data in PD (mainly related to impairment of the inspiratory muscles), little is known about hypoventilation in PD. We conclude that ventilatory dysfunction in PD has been poorly studied and little is known about its frequency and clinical relevance. Hence, there is a need to characterize the different phenotypes of ventilation disorders in PD, study their relationships with disease progression and assess their prognostic value. PMID:27314755

  20. Ventilatory endurance in athletes: a family study.

    PubMed

    Martin, B J; Chen, H I

    1982-05-01

    Endurance athletes possess superior ability to sustain high ventilation. However, it remains unknown if this high ventilatory endurance is an effect of training. As one approach to this question, we compared the breathing endurance of eight distance runners with that of eight of their siblings who were untrained. In two separate tests involving seated isocapnic hyperpnea, the athletes had greater ability to sustain high VE than did their brothers and sisters. In the first test, VE was voluntarily incremented by 30 l/min each 4 min. Before exhaustion, the athletes reached a VE that was a significantly greater fraction of their 12-s maximal voluntary ventilation than did the untrained siblings (75 vs. 62%; P less than 0.01). In the second test, 80% of the 12-s MVV was sustained until exhaustion. Endurance times for the athletes doubled those of the untrained siblings (7 vs. 3 min; P less than 0.05). The failure of elevated ventilatory endurance to occur in family clusters suggests that it may primarily result from training.

  1. [Prognostic factors for COPD patients with chronic hypercapnic respiratory failure and home ventilation].

    PubMed

    Budweiser, S; Jörres, R A; Heinemann, F; Pfeifer, M

    2009-09-01

    The prevalence of patients with severe COPD and chronic hypercapnic respiratory failure (CHRF) receiving non-invasive home ventilation has greatly increased. With regard to disease severity, a multidimensional assessment seems indicated. Base excess (BE), in particular, reflects the long-term metabolic response to chronic hypercapnia and thus constitutes a promising, easily accessible, integrative marker of CHRF. Infact, BE as well as nutritional status and lung hyperinflation have been identified as independent predictors of long-term survival. In addition and in a review with the literature, a broad panel of indices including frequent comorbidities are helpful for assessment and monitoring purposes of patients with CHRF. Accordingly, in view of the patients' individual risk profile, the decision about the initiation of NIV should probably not rely solely on symptoms and chronic persistent hypercapnia but include a spectrum of factors that specifically reflect disease severity. Owing to the physiologically positive effects of NIV and according to retrospective data, patients with COPD and recurrent hypercapnic respiratory decompensation and patients with prolonged mechanical ventilation and/or difficult weaning could also be considered for long-term non-invasive ventilation. This, however, has to be corroborated in future prospective trials. PMID:19750411

  2. Time Domains of the Hypoxic Ventilatory Response and Their Molecular Basis

    PubMed Central

    Pamenter, Matthew E.; Powell, Frank L.

    2016-01-01

    Ventilatory responses to hypoxia vary widely depending on the pattern and length of hypoxic exposure. Acute, prolonged, or intermittent hypoxic episodes can increase or decrease breathing for seconds to years, both during the hypoxic stimulus, and also after its removal. These myriad effects are the result of a complicated web of molecular interactions that underlie plasticity in the respiratory control reflex circuits and ultimately control the physiology of breathing in hypoxia. Since the time domains of the physiological hypoxic ventilatory response (HVR) were identified, considerable research effort has gone toward elucidating the underlying molecular mechanisms that mediate these varied responses. This research has begun to describe complicated and plastic interactions in the relay circuits between the peripheral chemoreceptors and the ventilatory control circuits within the central nervous system. Intriguingly, many of these molecular pathways seem to share key components between the different time domains, suggesting that varied physiological HVRs are the result of specific modifications to overlapping pathways. This review highlights what has been discovered regarding the cell and molecular level control of the time domains of the HVR, and highlights key areas where further research is required. Understanding the molecular control of ventilation in hypoxia has important implications for basic physiology and is emerging as an important component of several clinical fields. PMID:27347896

  3. The acute effect of mouth only breathing on time to completion, heart rate, rate of perceived exertion, blood lactate, and ventilatory measures during a high-intensity shuttle run sequence.

    PubMed

    Meir, Rudi; Zhao, Guang-Gao; Zhou, Shi; Beavers, Rosalind; Davie, Allan

    2014-04-01

    This study investigated the effect of restricting nasal breathing during a series of 20-m shuttle runs. Ten male participants (mean age = 21.7 ± 2.4 years, height = 1.80 ± 0.62 m, mass = 79.2 ± 10.4 kg, sum of 4 skinfolds = 54.5 ± 7.8 mm) were required to either (a) dive on the ground and complete a rolling sequence (condition = GRD) or (b) complete the shuttles while staying on their feet and tagging the line with 1 foot, at the end of each 20-m segment (condition = STD). The shuttle runs were completed with and without a nose clip (no clip = nc; with a clip = clip) under 4 different trial conditions in a randomized order (GRDnc; GRDclip; STDnc; and STDclip), requiring the participants to return on 4 separate occasions separated by 5-7 days. Heart rate was recorded throughout each trial, and the rate of perceived exertion (RPE) was measured at the completion of each shuttle sequence. Pretrial and posttrial lactate and respiratory function measures were also recorded. The general linear model with repeated measures analysis indicated that there was a significant effect for Roll (GRD > STD) (p ≤ 0.05) but not for Clip (p > 0.05) on total time to completion in the trials. There was no significant interaction of the conditions (Roll × Clip) for RPE (p > 0.05). Similarly, there was no significant effect for blood lactate measured 3 minutes post the last shuttle for Roll (p > 0.05) and Clip (p > 0.05). There was a significant main effect on the HR across all 6 time points (i.e., pre, intervals 1-4 and 10 minutes post) (p ≤ 0.05) and for Roll (GRD > STD) (p ≤ 0.05), but not for Clip (p > 0.05). No significant effect of Roll or Clip was found for any of the recorded ventilation measures (p > 0.05). On the basis of these findings, the use of restricted nasal breathing, while performing a high-intensity shuttle sequence as a method of increasing the acute training effect on athletes, is questionable, so strength and conditioning coaches should carefully consider

  4. Proportional assist ventilation and neurally adjusted ventilatory assist.

    PubMed

    Kacmarek, Robert M

    2011-02-01

    Patient-ventilator synchrony is a common problem with all patients actively triggering the mechanical ventilator. In many cases synchrony can be improved by vigilant adjustments by the managing clinician. However, in most institutions clinicians are not able to spend the time necessary to ensure synchrony in all patients. Proportional assist ventilation (PAV) and neurally adjusted ventilatory assist (NAVA) were both developed to improve patient-ventilator synchrony by proportionally unloading ventilatory effort and turning control of the ventilatory pattern over to the patient. This paper discusses PAV's and NAVA's theory of operation, general process of application, and the supporting literature.

  5. Naked mole rats exhibit metabolic but not ventilatory plasticity following chronic sustained hypoxia.

    PubMed

    Chung, Danielle; Dzal, Yvonne A; Seow, Allison; Milsom, William K; Pamenter, Matthew E

    2016-03-30

    Naked mole rats are among the most hypoxia-tolerant mammals identified and live in chronic hypoxia throughout their lives. The physiological mechanisms underlying this tolerance, however, are poorly understood. Most vertebrates hyperventilate in acute hypoxia and exhibit an enhanced hyperventilation following acclimatization to chronic sustained hypoxia (CSH). Conversely, naked mole rats do not hyperventilate in acute hypoxia and their response to CSH has not been examined. In this study, we explored mechanisms of plasticity in the control of the hypoxic ventilatory response (HVR) and hypoxic metabolic response (HMR) of freely behaving naked mole rats following 8-10 days of chronic sustained normoxia (CSN) or CSH. Specifically, we investigated the role of the major inhibitory neurotransmitter γ-amino butyric acid (GABA) in mediating these responses. Our study yielded three important findings. First, naked mole rats did not exhibit ventilatory plasticity following CSH, which is unique among adult animals studied to date. Second, GABA receptor (GABAR) antagonism altered breathing patterns in CSN and CSH animals and modulated the acute HVR in CSN animals. Third, naked mole rats exhibited GABAR-dependent metabolic plasticity following long-term hypoxia, such that the basal metabolic rate was approximately 25% higher in normoxic CSH animals than CSN animals, and GABAR antagonists modulated this increase.

  6. Vocal Cord Paralysis and Hypercapnic Respiratory Failure in a Patient with Familial Amyloidotic Polyneuropathy.

    PubMed

    Pıhtılı, Aylin; Bingol, Züleyha; Durmuş, Hacer; Parman, Yeşim; Kıyan, Esen

    2016-01-01

    We herein report a patient case with familial amyloidotic polyneuropathy (FAP) who presented with vocal cord paralysis (VCP). A 60-year-old man with FAP (Gly89Gln) presented with hoarseness and snoring for the previous two years. A chest X-ray demonstrated cardiomegaly and bilateral diaphragmatic elevation. The findings of a restrictive pattern on spirometry and daytime hypercapnia were consistent with respiratory muscle weakness related to neuropathy [forced expiratory volume (FEV1): 38%, forced vital capacity (FVC): 39%, FEV1/FVC: 77, partial pressure of arterial oxygen (PaO2): 80 mmHg, partial pressure of carbon dioxide in arterial blood (PaCO2): 52 mmHg]. An ear-nose-throat examination showed VCP. Polysomnography revealed severe obstructive sleep apnea (OSA). FAP may cause OSA by VCP and hypercapnic respiratory failure by respiratory muscle weakness. Therefore, an ear-nose-throat examination, spirometry, arterial blood gases analysis and polysomnography are important for these patients.

  7. Ventilatory and metabolic responses to acute hyperoxia in newborns.

    PubMed

    Mortola, J P; Frappell, P B; Dotta, A; Matsuoka, T; Fox, G; Weeks, S; Mayer, D

    1992-07-01

    Hyperoxia has previously been found to increase metabolic rate (oxygen consumption [VO2] and CO2 production [VCO2]) in newborn mammals. We asked whether the same occurs in the newborn infant. Breathing pattern was measured in 25 full-term infants, 1 to 2 days of age, from the spirometric record obtained with a pneumotachograph attached to a face mask. Concentrations of O2 and CO2 were continuously measured at the mouth; VO2 and VCO2 were computed as the product of VE and the difference between inspired and expired concentration of the respective gases, 5 min of air (FIO2 = 0.21) and 5 min of O2 (FIO2 = 1). A bias flow through the mask and pneumotachograph delivered the inspired gas and eliminated the effects of the instrumental dead space. In neither case did measurements at 1 min significantly differ from those taken at 5 min. In hyperoxia VE increased in 22 of the 25 infants, in average +18% (p less than 0.001, paired two-tailed t test). Because of a rise in tidal volume (+35%, p less than 0.001) and a decrease in breathing rate (-11%, p less than 0.005) alveolar ventilation (VA) increased by about 58% (p less than 0.001). VO2 and VCO2 increased by 25% and 17%, respectively (p less than 0.001). The rise in VO2 was too large to be explained by the greater respiratory work of the hyperventilation, whereas that of VCO2 was not large enough to fully explain the increase in VA. We conclude that in newborn humans, as in other newborn species, the normoxic metabolic rate seems to be limited by the availability of O2.(ABSTRACT TRUNCATED AT 250 WORDS)

  8. Rh protein expression in branchial neuroepithelial cells, and the role of ammonia in ventilatory control in fish.

    PubMed

    Zhang, Li; Michele Nawata, C; De Boeck, Gudrun; Wood, Chris M

    2015-08-01

    Bill Milsom has made seminal contributions to our understanding of ventilatory control in a wide range of vertebrates. Teleosts are particularly interesting, because they produce a 3rd, potentially toxic respiratory gas (ammonia) in large amounts. Fish are well known to hyperventilate under high environmental ammonia (HEA), but only recently has the potential role of ammonia in normal ventilatory control been investigated. It is now clear that ammonia can act directly as a ventilatory stimulant in trout, independent of its effects on acid-base balance. Even in ureotelic dogfish sharks, acute elevations in ammonia cause increases in ventilation. Peripherally, the detection of elevated ammonia resides in gill arches I and II in trout, and in vitro, neuroepithelial cells (NECs) from these arches are sensitive to ammonia, responding with elevations in intracellular Ca(2+) ([Ca(2+)]i). Centrally, hyperventilatory responses to ammonia correlate more closely with concentrations of ammonia in the brain than in plasma or CSF. After chronic HEA exposure, ventilatory responsiveness to ammonia is lost, associated with both an attenuation of the [Ca(2+)]i response in NECs, and the absence of elevation in brain ammonia concentration. Chronic exposure to HEA also causes increases in the mRNA expression of several Rh proteins (ammonia-conductive channels) in both brain and gills. "Single cell" PCR techniques have been used to isolate the individual responses of NECs versus other gill cell types. We suggest several circumstances (post-feeding, post-exercise) where the role of ammonia as a ventilatory stimulant may have adaptive benefits for O2 uptake in fish.

  9. Characterization of Ventilatory Modes in Dragonfly Nymph

    NASA Astrophysics Data System (ADS)

    Roh, Chris; Saxton-Fox, Theresa; Gharib, Morteza

    2013-11-01

    A dragonfly nymph's highly modified hindgut has multiple ventilatory modes: hyperventilation (i.e. jet propulsion), gulping ventilation (extended expiratory phase) and normal ventilation. Each mode involves dynamic manipulation of the exit diameter and pressure. To study the different fluid dynamics associated with the three modes, Anisopteran larvae of the family Aeshnidae were tethered onto a rod for flow visualization. The result showed distinct flow structures. The hyperventilation showed a highly turbulent and powerful jet that occurred at high frequency. The gulping ventilation produced a single vortex at a moderate frequency. The normal ventilation showed two distinct vortices, a low-Reynolds number vortex, followed by a high-Reynolds number vortex. Furthermore, a correlation of the formation of the vortices with the movement of the sternum showed that the dragonfly is actively controlling the timing and the speed of the vortices to have them at equal distance from the jet exit at the onset of inspiration. This behavior prevents inspiration of the oxygen deficient expirated water, resulting in the maximization of the oxygen intake. Supported by NSF GRFP.

  10. [Follow-up of respiratory symptoms and pulmonary ventilatory function in jute textile workers].

    PubMed

    Zuskin, E; Mustajbegović, J; Kanceljak, B

    1992-01-01

    The acute and chronic effects of exposure to jute dust on respiratory function was studied in a group of textile workers over a 19-year period. During the initial study the prevalence of all chronic respiratory symptoms was higher among the exposed workers compared with the controls. These differences in the prevalence were statistically significant at the time of the follow-up study, 19 years later. Four textile workers developed symptoms of occupational asthma during exposure to jute dust. Measurement of ventilatory capacity at both surveys demonstrated small but statistically significant mean acute reductions of FVC and FEV1 over the work shift. The values for FVC and FEV1 measured at the time of the follow-up study were significantly lower than the predicted normal values. The mean annual decrease for FVC and FEV1 was 35 ml/year what is greater than expected. Our data suggest that exposure to jute dust may in sensitive workers lead to the development of respiratory symptoms and diseases with less pronounced changes in ventilatory capacity.

  11. Cerebral blood flow regulation in women across menstrual phase: differential contribution of cyclooxygenase to basal, hypoxic, and hypercapnic vascular tone.

    PubMed

    Peltonen, Garrett L; Harrell, John W; Aleckson, Benjamin P; LaPlante, Kaylie M; Crain, Meghan K; Schrage, William G

    2016-08-01

    In healthy young women, basal cerebral blood flow (CBF) and cerebrovascular reactivity may change across the menstrual cycle, but mechanisms remain untested. When compared with the early follicular phase of the menstrual cycle, we hypothesized women in late follicular phase would exhibit: 1) greater basal CBF, 2) greater hypercapnic increases in CBF, 3) greater hypoxic increases in CBF, and 4) increased cyclooxygenase (COX) signaling. We measured middle cerebral artery velocity (MCAv, transcranial Doppler ultrasound) in 11 healthy women (23 ± 1 yr) during rest, hypoxia, and hypercapnia. Subjects completed four visits: two during the early follicular (∼day 3) and two during the late follicular (∼day 14) phases of the menstrual cycle, with and without COX inhibition (oral indomethacin). Isocapnic hypoxia elicited an SPO2 = 90% and SPO2 = 80% for 5 min each. Separately, hypercapnia increased end-tidal CO2 10 mmHg above baseline. Cerebral vascular conductance index (CVCi = MCAv/MABP·100, where MABP is mean arterial blood pressure) was calculated and a positive change reflected vasodilation (ΔCVCi). Basal CVCi was greater in the late follicular phase (P < 0.001). Indomethacin decreased basal CVCi (∼37%) and abolished the phase difference (P < 0.001). Hypoxic ΔCVCi was similar between phases and unaffected by indomethacin. Hypercapnic ΔCVCi was similar between phases, and indomethacin decreased hypercapnic ΔCVCi (∼68%; P < 0.001) similarly between phases. In summary, while neither hypercapnic nor hypoxic vasodilation is altered by menstrual phase, increased basal CBF in the late follicular phase is fully explained by a greater contribution of COX. These data provide new mechanistic insight into anterior CBF regulation across menstrual phases and contribute to our understanding of CBF regulation in women. PMID:27225949

  12. Effects of chronic normobaric hypoxic and hypercapnic exposure in rats: Prevention of experimental chronic mountain sickness by hypercapnia

    NASA Astrophysics Data System (ADS)

    Lincoln, B.; Bonkovsky, H. L.; Ou, Lo-Chang

    1987-09-01

    A syndrome of experimental chronic mountain sickness can be produced in the Hilltop strain of Sprague-Dawley rats by chronic hypobaric hypoxic exposure. This syndrome is characterized by polycythemia, plasma hemoglobinemia, pulmonary hypertension and right ventricular hypertrophy with eventual failure and death. It has generally been assumed that these changes are caused by chronic hypoxemia, not by hypobaric exposure per se. We have now confirmed this directly by showing that chronic normobaric hypoxic exposure (10.5% O2) produces similar hematologic and hemodynamic changes. Further, the addition of hypercapnic exposure to the hypoxic exposure blunted or prevented the effects of the hypoxic exposure probably by stimulating respiration, thus increasing the rate of oxygen delivery to the cells. Changes in the rate-controlling enzymes of hepatic heme metabolism, 5-aminolevulinate synthase and heme oxygenase, and in cytochrome(s) P-450, the major hepatic hemoprotein(s), were also measured in hypoxic and hypercapnic rats. Hypoxia decreased 5-aminolevulinate synthase and increased cytochrome(s) P-450, probably by increasing the size of a “regulatory” heme pool within hepatocytes. These changes were also prevented by the addition of hypercapnic to hypoxic exposure.

  13. Ventilation and hypoxic ventilatory responsiveness in Chinese-Tibetan residents at 3,658 m.

    PubMed

    Curran, L S; Zhuang, J; Sun, S F; Moore, L G

    1997-12-01

    When breathing ambient air at rest at 3,658 m altitude, Tibetan lifelong residents of 3,658 m ventilate as much as newcomers acclimatized to high altitude; they also ventilate more and have greater hypoxic ventilatory responses (HVRs) than do Han ("Chinese") long-term residents at 3,658 m. This suggests that Tibetan ancestry is advantageous in protecting resting ventilation levels during years of hypoxic exposure and is of interest in light of the permissive role of hypoventilation in the development of chronic mountain sickness, which is nearly absent among Tibetans. The existence of individuals with mixed Tibetan-Chinese ancestry (Han-Tibetans) residing at 3,658 m affords an opportunity to test this hypothesis. Eighteen men born in Lhasa, Tibet, China (3,658 m) to Tibetan mothers and Han fathers were compared with 27 Tibetan men and 30 Han men residing at 3,658 m who were previously studied. We used the same study procedures (minute ventilation was measured with a dry-gas flowmeter during room air breathing and hyperoxia and with a 13-liter spirometer-rebreathing system during the hypoxic and hypercapnic tests). During room air breathing at 3,658 m (inspired O2 pressure = 93 Torr), Han-Tibetans resembled Tibetans in ventilation (12.1 +/- 0.6 vs. 11.5+/- 0.5 l/min BTPS, respectively) but had HVR that were blunted (63 +/- 16 vs. 121 +/- 13, respectively, for HVR shape parameter A) and declined with increasing duration of high-altitude residence. During administered hyperoxia (inspired O2 pressure = 310 Torr) at 3,658 m, the paradoxical hyperventilation previously seen in Tibetan but not Han residents at 3,658 m (11.8 +/- 0.5 vs. 10.1 +/- 0.5 l/min BTPS) was absent in these Han-Tibetans (9.8 +/- 0.6 l/min BTPS). Thus, although longer duration of high-altitude residence appears to progressively blunt HVR among Han-Tibetans born and residing at 3, 658 m, their Tibetan ancestry appears protective in their maintenance of high resting ventilation levels despite

  14. Defining obstructive ventilatory defect in 2015

    PubMed Central

    Affes, Zied; Rekik, Salaheddine; Ben Saad, Helmi

    2015-01-01

    Introduction There is no clear consensus as to what constitutes an obstructive ventilatory defect (OVD): Is it FEV1/FVC

  15. Hypoxic ventilatory response of rats born at simulated altitude.

    PubMed

    Scotto, P; Barillari, R; Turek, Z; Kreuzer, F

    1988-04-01

    Steady-state ventilatory response to isocapnic hypoxia was measured in awake rats: a) resident at sea level (Control); b) born at sea level and acclimatized to a simulated altitude of 3500 m (Newcomers); c) born and raised for two generations at a simulated altitude of 3500 m (HA-II Generation). Arterial PO2, PCO2, and pH were measured at the same time as ventilation. Resting ventilation (mean +/- SE) on room air in Control, Newcomers, and HA-II Generation was 707 +/- 25, 811 +/- 28 and 878 +/- 21 ml.min-1.kg-1, respectively. The ratios of ventilations measured at PaO2 55 and 100 Torr were 1.61 for Control, 1.52 for Newcomers, and 1.60 for HA-II Generation and were not significantly different from one another. The ventilatory response to 5% CO2 in air was also similar in all three groups. After four days at sea level, ventilatory responses of HA-II Generation to normoxia or isocapnic hypoxia were the same as those of sea level control. We conclude that the HA-II Generation groups had ventilatory responses to hypoxia that did not differ from those of Newcomers acclimatized to the same altitude. Unlike man, rats that were born and raised at altitude for two generations did not show any "blunting" of the ventilatory response to hypoxia.

  16. Vocal Cord Paralysis and Hypercapnic Respiratory Failure in a Patient with Familial Amyloidotic Polyneuropathy.

    PubMed

    Pıhtılı, Aylin; Bingol, Züleyha; Durmuş, Hacer; Parman, Yeşim; Kıyan, Esen

    2016-01-01

    We herein report a patient case with familial amyloidotic polyneuropathy (FAP) who presented with vocal cord paralysis (VCP). A 60-year-old man with FAP (Gly89Gln) presented with hoarseness and snoring for the previous two years. A chest X-ray demonstrated cardiomegaly and bilateral diaphragmatic elevation. The findings of a restrictive pattern on spirometry and daytime hypercapnia were consistent with respiratory muscle weakness related to neuropathy [forced expiratory volume (FEV1): 38%, forced vital capacity (FVC): 39%, FEV1/FVC: 77, partial pressure of arterial oxygen (PaO2): 80 mmHg, partial pressure of carbon dioxide in arterial blood (PaCO2): 52 mmHg]. An ear-nose-throat examination showed VCP. Polysomnography revealed severe obstructive sleep apnea (OSA). FAP may cause OSA by VCP and hypercapnic respiratory failure by respiratory muscle weakness. Therefore, an ear-nose-throat examination, spirometry, arterial blood gases analysis and polysomnography are important for these patients. PMID:27374684

  17. Increased hypoxic ventilatory sensitivity during exercise in man: are neural afferents necessary?

    PubMed Central

    Pandit, J J; Bergstrom, E; Frankel, H L; Robbins, P A

    1994-01-01

    1. The acute ventilatory response to 3 min periods of hypoxia (AHR) was examined in nine patients with clinically complete spinal cord transection (T4-T7) during (a) rest and (b) electrically induced leg exercise (EEL). 2. EEL was produced by surface electrode stimulation of the quadriceps muscles so as to cause the legs to extend at the knee against gravity. End-tidal PCO2 was held constant 1-2 mmHg above resting values throughout both protocols. 3. On exercise, the average increase in metabolic CO2 production (VCO2 +/- S.E.M.) was 41 +/- 5 ml min-1. Venous lactate levels did not rise with exercise. 4. Baseline euoxic ventilation did not increase significantly with EEL, but there was a consistent and highly significant increase in the ventilatory response to hypoxia during EEL (mean delta AHR +/- S.E.M. of 1.6 +/- 0.21 min-1). 5. We conclude that an increase in hypoxic sensitivity during exercise can occur in the absence of volitional control of exercise and in the absence of afferent neural input from the limbs. PMID:8071884

  18. Effects of hypercapnia and hypocapnia on ventilatory variability and the chaotic dynamics of ventilatory flow in humans.

    PubMed

    Fiamma, Marie-Noëlle; Straus, Christian; Thibault, Sylvain; Wysocki, Marc; Baconnier, Pierre; Similowski, Thomas

    2007-05-01

    In humans, lung ventilation exhibits breath-to-breath variability and dynamics that are nonlinear, complex, sensitive to initial conditions, unpredictable in the long-term, and chaotic. Hypercapnia, as produced by the inhalation of a CO(2)-enriched gas mixture, stimulates ventilation. Hypocapnia, as produced by mechanical hyperventilation, depresses ventilation in animals and in humans during sleep, but it does not induce apnea in awake humans. This emphasizes the suprapontine influences on ventilatory control. How cortical and subcortical commands interfere thus depend on the prevailing CO(2) levels. However, CO(2) also influences the variability and complexity of ventilation. This study was designed to describe how this occurs and to test the hypothesis that CO(2) chemoreceptors are important determinants of ventilatory dynamics. Spontaneous ventilatory flow was recorded in eight healthy subjects. Breath-by-breath variability was studied through the coefficient of variation of several ventilatory variables. Chaos was assessed with the noise titration method (noise limit) and characterized with numerical indexes [largest Lyapunov exponent (LLE), sensitivity to initial conditions; Kolmogorov-Sinai entropy (KSE), unpredictability; and correlation dimension (CD), irregularity]. In all subjects, under all conditions, a positive noise limit confirmed chaos. Hypercapnia reduced breathing variability, increased LLE (P = 0.0338 vs. normocapnia; P = 0.0018 vs. hypocapnia), increased KSE, and slightly reduced CD. Hypocapnia increased variability, decreased LLE and KSE, and reduced CD. These results suggest that chemoreceptors exert a strong influence on ventilatory variability and complexity. However, complexity persists in the quasi-absence of automatic drive. Ventilatory variability and complexity could be determined by the interaction between the respiratory central pattern generator and suprapontine structures. PMID:17218438

  19. Cardiopulmonary resuscitation interface adapted for postextubation continuous noninvasive ventilatory support.

    PubMed

    Bach, John R; Saporito, Louis Ralph

    2015-09-01

    The authors report that a new oral interface designed for cardiopulmonary resuscitation and use during anesthesia permitted the successful extubation of an "unweanable" 27-yr-old woman with nemaline rod myopathy to continuous noninvasive ventilatory support. She had failed two previous extubation attempts. Tracheotomy and institutional care were avoided as a result. PMID:26135377

  20. Measurement of oxygen extraction fraction (OEF): An optimized BOLD signal model for use with hypercapnic and hyperoxic calibration.

    PubMed

    Merola, Alberto; Murphy, Kevin; Stone, Alan J; Germuska, Michael A; Griffeth, Valerie E M; Blockley, Nicholas P; Buxton, Richard B; Wise, Richard G

    2016-04-01

    Several techniques have been proposed to estimate relative changes in cerebral metabolic rate of oxygen consumption (CMRO2) by exploiting combined BOLD fMRI and cerebral blood flow data in conjunction with hypercapnic or hyperoxic respiratory challenges. More recently, methods based on respiratory challenges that include both hypercapnia and hyperoxia have been developed to assess absolute CMRO2, an important parameter for understanding brain energetics. In this paper, we empirically optimize a previously presented "original calibration model" relating BOLD and blood flow signals specifically for the estimation of oxygen extraction fraction (OEF) and absolute CMRO2. To do so, we have created a set of synthetic BOLD signals using a detailed BOLD signal model to reproduce experiments incorporating hypercapnic and hyperoxic respiratory challenges at 3T. A wide range of physiological conditions was simulated by varying input parameter values (baseline cerebral blood volume (CBV0), baseline cerebral blood flow (CBF0), baseline oxygen extraction fraction (OEF0) and hematocrit (Hct)). From the optimization of the calibration model for estimation of OEF and practical considerations of hypercapnic and hyperoxic respiratory challenges, a new "simplified calibration model" is established which reduces the complexity of the original calibration model by substituting the standard parameters α and β with a single parameter θ. The optimal value of θ is determined (θ=0.06) across a range of experimental respiratory challenges. The simplified calibration model gives estimates of OEF0 and absolute CMRO2 closer to the true values used to simulate the experimental data compared to those estimated using the original model incorporating literature values of α and β. Finally, an error propagation analysis demonstrates the susceptibility of the original and simplified calibration models to measurement errors and potential violations in the underlying assumptions of isometabolism

  1. Ventilatory strategies in obstructive lung disease.

    PubMed

    Parrilla, Francisco José; Morán, Indalecio; Roche-Campo, Ferran; Mancebo, Jordi

    2014-08-01

    Chronic obstructive pulmonary disease (COPD) is characterized by expiratory flow limitation (EFL) due to progressive airflow obstruction. The various mechanisms that cause EFL are central to understanding the physiopathology of COPD. At the end of expiration, dynamic inflation may occur due to incomplete emptying the lungs. This "extra" volume increases the alveolar pressure at the end of the expiration, resulting in auto-positive end-expiratory pressure (PEEP) or PEEPi. Acute exacerbations of COPD may result in increased airway resistance and inspiratory effort, further leading to dynamic hyperinflation. COPD exacerbations may be triggered by environmental exposures, infections (viral and bacterial), or bronchial inflammation, and may result in worsening respiratory failure requiring mechanical ventilation (MV). Acute exacerbations of COPD need to be distinguished from other events such as cardiac failure or pulmonary emboli. Strategies to treat acute respiratory failure (ARF) in COPD patients include noninvasive ventilation (NIV), pressure support ventilation, and tracheal intubation with MV. In this review, we discuss invasive and noninvasive techniques to address ARF in this patient population. When invasive MV is used, settings should be adjusted in a way that minimizes hyperinflation, while providing reasonable gas exchange, respiratory muscle rest, and proper patient-ventilator interaction. Further, weaning from MV may be difficult in these patients, and factors amenable to pharmacological correction (such as increased bronchial resistance, tracheobronchial infections, and heart failure) are to be systematically searched and treated. In selected patients, early use of NIV may hasten the process of weaning from MV and improve outcomes.

  2. Ventilatory strategies in obstructive lung disease.

    PubMed

    Parrilla, Francisco José; Morán, Indalecio; Roche-Campo, Ferran; Mancebo, Jordi

    2014-08-01

    Chronic obstructive pulmonary disease (COPD) is characterized by expiratory flow limitation (EFL) due to progressive airflow obstruction. The various mechanisms that cause EFL are central to understanding the physiopathology of COPD. At the end of expiration, dynamic inflation may occur due to incomplete emptying the lungs. This "extra" volume increases the alveolar pressure at the end of the expiration, resulting in auto-positive end-expiratory pressure (PEEP) or PEEPi. Acute exacerbations of COPD may result in increased airway resistance and inspiratory effort, further leading to dynamic hyperinflation. COPD exacerbations may be triggered by environmental exposures, infections (viral and bacterial), or bronchial inflammation, and may result in worsening respiratory failure requiring mechanical ventilation (MV). Acute exacerbations of COPD need to be distinguished from other events such as cardiac failure or pulmonary emboli. Strategies to treat acute respiratory failure (ARF) in COPD patients include noninvasive ventilation (NIV), pressure support ventilation, and tracheal intubation with MV. In this review, we discuss invasive and noninvasive techniques to address ARF in this patient population. When invasive MV is used, settings should be adjusted in a way that minimizes hyperinflation, while providing reasonable gas exchange, respiratory muscle rest, and proper patient-ventilator interaction. Further, weaning from MV may be difficult in these patients, and factors amenable to pharmacological correction (such as increased bronchial resistance, tracheobronchial infections, and heart failure) are to be systematically searched and treated. In selected patients, early use of NIV may hasten the process of weaning from MV and improve outcomes. PMID:25111641

  3. Ibuprofen Blunts Ventilatory Acclimatization to Sustained Hypoxia in Humans.

    PubMed

    Basaran, Kemal Erdem; Villongco, Michael; Ho, Baran; Ellis, Erika; Zarndt, Rachel; Antonova, Julie; Hopkins, Susan R; Powell, Frank L

    2016-01-01

    Ventilatory acclimatization to hypoxia is a time-dependent increase in ventilation and the hypoxic ventilatory response (HVR) that involves neural plasticity in both carotid body chemoreceptors and brainstem respiratory centers. The mechanisms of such plasticity are not completely understood but recent animal studies show it can be blocked by administering ibuprofen, a nonsteroidal anti-inflammatory drug, during chronic hypoxia. We tested the hypothesis that ibuprofen would also block the increase in HVR with chronic hypoxia in humans in 15 healthy men and women using a double-blind, placebo controlled, cross-over trial. The isocapnic HVR was measured with standard methods in subjects treated with ibuprofen (400 mg every 8 hrs) or placebo for 48 hours at sea level and 48 hours at high altitude (3,800 m). Subjects returned to sea level for at least 30 days prior to repeating the protocol with the opposite treatment. Ibuprofen significantly decreased the HVR after acclimatization to high altitude compared to placebo but it did not affect ventilation or arterial O2 saturation breathing ambient air at high altitude. Hence, compensatory responses prevent hypoventilation with decreased isocapnic ventilatory O2-sensitivity from ibuprofen at this altitude. The effect of ibuprofen to decrease the HVR in humans provides the first experimental evidence that a signaling mechanism described for ventilatory acclimatization to hypoxia in animal models also occurs in people. This establishes a foundation for the future experiments to test the potential role of different mechanisms for neural plasticity and ventilatory acclimatization in humans with chronic hypoxemia from lung disease.

  4. Increased ventilatory variability and complexity in patients with hyperventilation disorder.

    PubMed

    Bokov, Plamen; Fiamma, Marie-Noëlle; Chevalier-Bidaud, Brigitte; Chenivesse, Cécile; Straus, Christian; Similowski, Thomas; Delclaux, Christophe

    2016-05-15

    It has been hypothesized that hyperventilation disorders could be characterized by an abnormal ventilatory control leading to enhanced variability of resting ventilation. The variability of tidal volume (VT) often depicts a nonnormal distribution that can be described by the negative slope characterizing augmented breaths formed by the relationship between the probability density distribution of VT and VT on a log-log scale. The objectives of this study were to describe the variability of resting ventilation [coefficient of variation (CV) of VT and slope], the stability in respiratory control (loop, controller and plant gains characterizing ventilatory-chemoresponsiveness interactions) and the chaotic-like dynamics (embedding dimension, Kappa values characterizing complexity) of resting ventilation in patients with a well-defined dysfunctional breathing pattern characterized by air hunger and constantly decreased PaCO2 during a cardiopulmonary exercise test. Compared with 14 healthy subjects with similar anthropometrics, 23 patients with hyperventilation were characterized by increased variability of resting tidal ventilation (CV of VT median [interquartile]: 26% [19-35] vs. 36% [28-48], P = 0.020; slope: -6.63 [-7.65; -5.36] vs. -3.88 [-5.91; -2.66], P = 0.004) that was not related to increased chemical drive (loop gain: 0.051 [0.039-0.221] vs. 0.044 [0.012-0.087], P = 0.149) but that was related to an increased ventilatory complexity (Kappa values, P < 0.05). Plant gain was decreased in patients and correlated with complexity (with Kappa 5 - degree 5: Rho = -0.48, P = 0.006). In conclusion, well-defined patients suffering from hyperventilation disorder are characterized by increased variability of their resting ventilation due to increased ventilatory complexity with stable ventilatory-chemoresponsiveness interactions. PMID:26869707

  5. Human diaphragm efficiency estimated as power output relative to activation increases with hypercapnic hyperpnea.

    PubMed

    Finucane, Kevin E; Singh, Bhajan

    2009-11-01

    Hyperpnea with exercise or hypercapnia causes phasic contraction of abdominal muscles, potentially lengthening the diaphragm at end expiration and unloading it during inspiration. Muscle efficiency in vitro varies with load, fiber length, and precontraction stretch. To examine whether these properties of muscle contractility determine diaphragm efficiency (Eff(di)) in vivo, we measured Eff(di) in six healthy adults breathing air and during progressive hypercapnia at three levels of end-tidal Pco(2) with mean values of 48 (SD 2), 55 (SD 2), and 61 (SD 1) Torr. Eff(di) was estimated as the ratio of diaphragm power (Wdi) [the product of mean inspiratory transdiaphragmatic pressure, diaphragm volume change (DeltaVdi) measured fluoroscopically, and 1/inspiratory duration (Ti(-1))] to activation [root mean square values of inspiratory diaphragm electromyogram (RMS(di)) measured from esophageal electrodes]. At maximum hypercapnea relative to breathing air, 1) gastric pressure and diaphragm length at end expiration (Pg(ee) and Ldi(ee), respectively) increased 1.4 (SD 0.2) and 1.13 (SD 0.08) times, (P < 0.01 for both); 2) inspiratory change (Delta) in Pg decreased from 4.5 (SD 2.2) to -7.7 (SD 3.8) cmH(2)O (P < 0.001); 3) DeltaVdi.Ti(-1), Wdi, RMS(di), and Eff(di) increased 2.7 (SD 0.6), 4.9 (SD 1.8), 2.6 (SD 0.9), and 1.8 (SD 0.3) times, respectively (P < 0.01 for all); and 4) net and inspiratory Wdi were not different (P = 0.4). Eff(di) was predicted from Ldi(ee) (P < 0.001), Pg(ee) (P < 0.001), DeltaPg.Ti(-1) (P = 0.03), and DeltaPg (P = 0.04) (r(2) = 0.52) (multivariate regression analysis). We conclude that, with hypercapnic hyperpnea, 1) approximately 47% of the maximum increase of Wdi was attributable to increased Eff(di); 2) Eff(di) increased due to preinspiratory lengthening and inspiratory unloading of the diaphragm, consistent with muscle behavior in vitro; 3) passive recoil of the diaphragm did not contribute to inspiratory Wdi or Eff(di); and 4) phasic

  6. Orexin receptors in the developing piglet hypothalamus, and effects of nicotine and intermittent hypercapnic hypoxia exposures.

    PubMed

    Hunt, Nicholas J; Waters, Karen A; Machaalani, Rita

    2013-05-01

    Orexin and its receptors (OxR1 and OxR2) play a significant role in arousal and sleep regulation. Using developing piglets, we aimed to determine the effects of nicotine and Intermittent Hypercapnic Hypoxia (IHH), alone or in combination, on orexin receptor expression in the hypothalamus. Four piglet groups were studied: control (n=14), nicotine (n=14), IHH (n=10) and nic+IHH (n=14). Applying immunohistochemistry for OxR1 and OxR2 expression, eight nuclei/areas of the hypothalamus: dorsal medial nucleus (DMN), arcuate nucleus (ARC), perifornical area (PFA), paraventricular nucleus (PVN), lateral hypothalamic area (LHA), ventral medial nucleus (VMN), supraoptic nucleus, retrochiasmatic part (SONr) and tuberal mammillary nucleus (TMN), were studied. Compared to controls, OxR1 and OxR2 were increased due to exposures, however this was region dependent. Nicotine increased OxR1 in the DMN (P<0.001) and SONr (P=0.036), and OxR2 in the DMN (P<0.001), VMN (P=0.014) and the TMN (P=0.026). IHH increased OxR1 in the DMN, PVN, VMN and SONr (P<0.01 for all), and OxR2 in DMN (P<0.001), PFA (P=0.001), PVN (P=0.004), VMN (P=0.041) and the TMN (P<0.001). The nic+IHH exposure increased OxR1 expression in all nuclei (TMN excluded) however, the changes were not significantly different from IHH alone. For OxR2, the increased expression after nic+IHH was significant compared to IHH in the DMN, ARC and SONr. These results show that nicotine increases orexin receptor expression in a region dependent manner. IHH induced increases were specific to arousal and stress related regions and nic+IHH results suggest that for OxR1, nicotine has no additive effect whereas for OxR2 it does, and is region dependent. PMID:23500635

  7. Carotid body hyperplasia and enhanced ventilatory responses to hypoxia in mice with heterozygous deficiency of PHD2

    PubMed Central

    Bishop, Tammie; Talbot, Nick P; Turner, Philip J; Nicholls, Lynn G; Pascual, Alberto; Hodson, Emma J; Douglas, Gillian; Fielding, James W; Smith, Thomas G; Demetriades, Marina; Schofield, Christopher J; Robbins, Peter A; Pugh, Christopher W; Buckler, Keith J; Ratcliffe, Peter J

    2013-01-01

    Oxygen-dependent prolyl hydroxylation of hypoxia-inducible factor (HIF) by a set of closely related prolyl hydroxylase domain enzymes (PHD1, 2 and 3) regulates a range of transcriptional responses to hypoxia. This raises important questions about the role of these oxygen-sensing enzymes in integrative physiology. We investigated the effect of both genetic deficiency and pharmacological inhibition on the change in ventilation in response to acute hypoxic stimulation in mice. Mice exposed to chronic hypoxia for 7 days manifest an exaggerated hypoxic ventilatory response (HVR) (10.8 ± 0.3 versus 4.1 ± 0.7 ml min−1 g−1 in controls; P < 0.01). HVR was similarly exaggerated in PHD2+/− animals compared to littermate controls (8.4 ± 0.7 versus 5.0 ± 0.8 ml min−1 g−1; P < 0.01). Carotid body volume increased (0.0025 ± 0.00017 in PHD2+/− animals versus 0.0015 ± 0.00019 mm3 in controls; P < 0.01). In contrast, HVR in PHD1−/− and PHD3−/− mice was similar to littermate controls. Acute exposure to a small molecule PHD inhibitor (PHI) (2-(1-chloro-4-hydroxyisoquinoline-3-carboxamido) acetic acid) did not mimic the ventilatory response to hypoxia. Further, 7 day administration of the PHI induced only modest increases in HVR and carotid body cell proliferation, despite marked stimulation of erythropoiesis. This was in contrast with chronic hypoxia, which elicited both exaggerated HVR and cellular proliferation. The findings demonstrate that PHD enzymes modulate ventilatory sensitivity to hypoxia and identify PHD2 as the most important enzyme in this response. They also reveal differences between genetic inactivation of PHDs, responses to hypoxia and responses to a pharmacological inhibitor, demonstrating the need for caution in predicting the effects of therapeutic modulation of the HIF hydroxylase system on different physiological responses. PMID:23690557

  8. Effect of exercise level on ventilatory adaptation to respirator use.

    PubMed

    Harber, P; Shimozaki, S; Barrett, T; Fine, G

    1990-10-01

    The effect of exercise on the adaptation to an air-purifying respirator type load (dead space + inspiratory resistance) was studied in a group of 13 volunteers with a rapidly incremental exercise protocol. The difference between loaded and unloaded breathing at each exercise level was determined for each subject for a series of parameters describing the ventilatory work to overcome the respirator load pattern of breathing and metabolic work. Linear regression and t tests determined the average effect of the respirator load and the extent to which this effect was affected by the level of exercise. The inspiratory time and duty cycle were increased by the load, and exercise did not significantly affect the magnitude of this adaptation. High exercise did, however, increase the magnitude of the effect of the respiratory load on ventilatory work. These findings suggest that constraints to respiratory pattern adjustment, which may decrease respirator tolerance, occur at high exercise levels. PMID:2262825

  9. Ventilatory responses to dynamic exercise elicited by intramuscular sensors

    NASA Technical Reports Server (NTRS)

    Smith, S. A.; Gallagher, K. M.; Norton, K. H.; Querry, R. G.; Welch-O'Connor, R. M.; Raven, P. B.

    1999-01-01

    PURPOSE: Eight subjects, aged 27.0+/-1.6 yr, performed incremental workload cycling to investigate the contribution of skeletal muscle mechano- and metaboreceptors to ventilatory control during dynamic exercise. METHODS: Each subject performed four bouts of exercise: exercise with no intervention (CON); exercise with bilateral thigh cuffs inflated to 90 mm Hg (CUFF); exercise with application of lower-body positive pressure (LBPP) to 45 torr (PP); and exercise with 90 mm Hg thigh cuff inflation and 45 torr LBPP (CUFF+PP). Ventilatory responses and pulmonary gas exchange variables were collected breath-by-breath with concomitant measurement of leg intramuscular pressure. RESULTS: Ventilation (VE) was significantly elevated from CON during PP and CUFF+PP at workloads corresponding to > or = 60% CON peak oxygen uptake (VO2peak) and during CUFF at workloads > or = 80% CON VO2peak, P < 0.05. The VO2 at which ventilatory threshold occurred was significantly reduced from CON (2.17+/-0.28 L x min(-1)) to 1.60+/-0.19 L x min(-1), 1.45+/-0.15 L x min(-1), and 1.15+/-0.11 L x min(-1) during CUFF, PP, and CUFF+PP, respectively. The slope of the linear regression describing the VE/CO2 output relationship was increased from CON by approximately 22% during CUFF, 40% during PP, and 41% during CUFF+PP. CONCLUSIONS: As intramuscular pressure was significantly elevated immediately upon application of LBPP during PP and CUFF+PP without a concomitant increase in VE, it seems unlikely that LBPP-induced increases in VE can be attributed to activation of the mechanoreflex. These findings suggest that LBPP-induced reductions in perfusion pressure and decreases in venous outflow resulting from inflation of bilateral thigh cuffs may generate a metabolite sensitive intramuscular ventilatory stimulus.

  10. Exercise ventilatory inefficiency in mild to end-stage COPD.

    PubMed

    Neder, J Alberto; Arbex, Flavio F; Alencar, Maria Clara N; O'Donnell, Conor D J; Cory, Julia; Webb, Kathy A; O'Donnell, Denis E

    2015-02-01

    Ventilatory inefficiency during exercise is a key pathophysiological feature of chronic obstructive pulmonary disease. Currently, it is unknown how this physiological marker relates to clinically relevant outcomes as resting ventilatory impairment progresses across disease stages. Slope and intercept of the linear region of the ventilation-carbon dioxide output relationship and the ratio between these variables, at the lowest point (nadir), were contrasted in 316 patients with Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages 1-4 (forced expiratory volume in 1 s, ranging from 148% pred to 12% pred) and 69 aged- and gender-matched controls, Compared to controls, slope and intercept were higher in GOLD stages 1 and 2, leading to higher nadirs (p<0.05). Despite even larger intercepts in GOLD stages 3 and 4, slopes diminished as disease evolved (from mean±sd 35±6 in GOLD stage 1 to 24±5 in GOLD stage 3, p<0.05). As a result, there were no significant differences in nadirs among patient groups. Higher intercepts, across all stages (p<0.01), and to a lesser extent lower slopes in GOLD stages 2-4 (p<0.05), were related to greater mechanical constraints, worsening pulmonary gas exchange, higher dyspnoea scores, and poorer exercise capacity. Increases in the ventilation intercept best indicate the progression of exercise ventilatory inefficiency across the whole spectrum of chronic obstructive pulmonary disease severity.

  11. Ventilatory Function in Young Adults and Dietary Antioxidant Intake

    PubMed Central

    Garcia-Larsen, Vanessa; Amigo, Hugo; Bustos, Patricia; Bakolis, Ioannis; Rona, Roberto J.

    2015-01-01

    Dietary antioxidants may protect against poor ventilatory function. We assessed the relation between ventilatory function and antioxidant components of diet in young Chileans. Forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), and the ratio FEV1/FVC were measured in 1232 adults aged 22–28 years, using a Vitalograph device. Dietary intake was ascertained with a food frequency questionnaire (FFQ) designed for this study, from which nutrient and flavonoid intakes were estimated. Dietary patterns were derived with Principal Component Analysis (PCA). After controlling for potential confounders, dietary intake of total catechins was positively associated with FVC (Regression coefficient (RC) of highest vs. lowest quintile of intake 0.07; 95% CI 0.01 to 0.15; p per trend 0.006). Total fruit intake was related to FVC (RC of highest vs. lowest quintile 0.08; 95% CI 0.003 to 0.15; p per trend 0.02). Intake of omega 3 fatty acids was associated with a higher FEV1 (RC for highest vs. lowest quintile 0.08; 95% CI 0.01 to 0.15 L; p per trend 0.02) and with FVC 0.08 (RC in highest vs. lowest quintile of intake 0.08, 95% CI 0.001 to 0.16; p per trend 0.04). Our results show that fresh fruits, flavonoids, and omega 3 fatty acids may contribute to maintain ventilatory function. PMID:25884660

  12. Ventilatory patterns differ between maximal running and cycling.

    PubMed

    Tanner, David A; Duke, Joseph W; Stager, Joel M

    2014-01-15

    To determine the effect of exercise mode on ventilatory patterns, 22 trained men performed two maximal graded exercise tests; one running on a treadmill and one cycling on an ergometer. Tidal flow-volume (FV) loops were recorded during each minute of exercise with maximal loops measured pre and post exercise. Running resulted in a greater VO2peak than cycling (62.7±7.6 vs. 58.1±7.2mLkg(-1)min(-1)). Although maximal ventilation (VE) did not differ between modes, ventilatory equivalents for O2 and CO2 were significantly larger during maximal cycling. Arterial oxygen saturation (estimated via ear oximeter) was also greater during maximal cycling, as were end-expiratory (EELV; 3.40±0.54 vs. 3.21±0.55L) and end-inspiratory lung volumes, (EILV; 6.24±0.88 vs. 5.90±0.74L). Based on these results we conclude that ventilatory patterns differ as a function of exercise mode and these observed differences are likely due to the differences in posture adopted during exercise in these modes.

  13. [Effect of diaphragmatic fatigue on ventilatory response to carbon dioxide].

    PubMed

    Wakai, Y; Yoshimura, A; Katagiri, S; Yoshino, K; Konno, K

    1992-12-01

    To clarify the effect of respiratory muscle fatigue on ventilatory response to carbon dioxide, we performed CO2 rebreathing study before and after diaphragmatic fatigue in nine healthy males. Diaphragmatic fatigue was induced by inspiratory resistor loading and confirmed by the increase in Tension Time Index and the decrease in Pdi max at FRC. The effects of diaphragmatic fatigue were as follows: 1) S and B value of VE-CO2 curve did not change. 2) P1-CO2 curve shifted to the left but the slope of the curve did not change. 3) delta Ppl response to CO2 decreased, but delta Pdi response to CO2 did not change. 4) The increase in respiratory accessory muscle EMG was more prominent, compared to diaphragmatic EMG. 5) Rib cage movement became more marked. In conclusion, diaphragmatic fatigue (with 60 percent decrease in Pdi max at FRC) does not affect on ventilatory response to carbon dioxide. To maintain the homeostasis of the chemical ventilatory feedback system, diaphragmatic dysfunction is compensated by the increased activity of respiratory accessory muscles with possible increase in neural drive. PMID:1306216

  14. Ventilatory function in young adults and dietary antioxidant intake.

    PubMed

    Garcia-Larsen, Vanessa; Amigo, Hugo; Bustos, Patricia; Bakolis, Ioannis; Rona, Roberto J

    2015-04-15

    Dietary antioxidants may protect against poor ventilatory function. We assessed the relation between ventilatory function and antioxidant components of diet in young Chileans. Forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), and the ratio FEV1/FVC were measured in 1232 adults aged 22-28 years, using a Vitalograph device. Dietary intake was ascertained with a food frequency questionnaire (FFQ) designed for this study, from which nutrient and flavonoid intakes were estimated. Dietary patterns were derived with Principal Component Analysis (PCA). After controlling for potential confounders, dietary intake of total catechins was positively associated with FVC (Regression coefficient (RC) of highest vs. lowest quintile of intake 0.07; 95% CI 0.01 to 0.15; p per trend 0.006). Total fruit intake was related to FVC (RC of highest vs. lowest quintile 0.08; 95% CI 0.003 to 0.15; p per trend 0.02). Intake of omega 3 fatty acids was associated with a higher FEV1 (RC for highest vs. lowest quintile 0.08; 95% CI 0.01 to 0.15 L; p per trend 0.02) and with FVC 0.08 (RC in highest vs. lowest quintile of intake 0.08, 95% CI 0.001 to 0.16; p per trend 0.04). Our results show that fresh fruits, flavonoids, and omega 3 fatty acids may contribute to maintain ventilatory function.

  15. Physiological impact of patent foramen ovale on pulmonary gas exchange, ventilatory acclimatization, and thermoregulation.

    PubMed

    Lovering, Andrew T; Elliott, Jonathan E; Davis, James T

    2016-08-01

    The foramen ovale, which is part of the normal fetal cardiopulmonary circulation, fails to close after birth in ∼35% of the population and represents a potential source of right-to-left shunt. Despite the prevalence of patent foramen ovale (PFO) in the general population, cardiopulmonary, exercise, thermoregulatory, and altitude physiologists may have underestimated the potential effect of this shunted blood flow on normal physiological processes in otherwise healthy humans. Because this shunted blood bypasses the respiratory system, it would not participate in either gas exchange or respiratory system cooling and may have impacts on other physiological processes that remain undetermined. The consequences of this shunted blood flow in PFO-positive (PFO+) subjects can potentially have a significant, and negative, impact on the alveolar-to-arterial oxygen difference (AaDO2), ventilatory acclimatization to high altitude and respiratory system cooling with PFO+ subjects having a wider AaDO2 at rest, during exercise after acclimatization, blunted ventilatory acclimatization, and a higher core body temperature (∼0.4(°)C) at rest and during exercise. There is also an association of PFO with high-altitude pulmonary edema and acute mountain sickness. These effects on physiological processes are likely dependent on both the presence and size of the PFO, with small PFOs not likely to have significant/measureable effects. The PFO can be an important determinant of normal physiological processes and should be considered a potential confounder to the interpretation of former and future data, particularly in small data sets where a significant number of PFO+ subjects could be present and significantly impact the measured outcomes. PMID:27418686

  16. Upper airway CO2 receptors in tegu lizards: localization and ventilatory sensitivity.

    PubMed

    Coates, E L; Ballam, G O

    1987-01-01

    1. Tidal volume, end-tidal CO2, and ventilatory frequency in Tupinambis nigropunctatus were measured in response to CO2 (1-4%) delivered to either the mouth or nares. Additionally, the sensitivity of the ventilatory response to nasal CO2 was evaluated at CO2 concentrations less than 1%. The ventilatory parameters were also measured in response to CO2 (1-4%) delivered to the nares after the olfactory peduncle was transected. 2. It was found that (0.4-4%) nasal CO2 depressed ventilatory frequency by 9% to 83% respectively, while tidal volume was not significantly altered. CO2 (1-4%) delivered to the mouth produced no apparent changes in any of the ventilatory parameters. Following transection of the olfactory peduncle, nasal CO2 was ineffective in producing any change in ventilatory frequency or depth. 3. These findings indicate that CO2-sensitive receptors are located in either the nasal or vomeronasal membranes of tegu lizards and that the olfactory peduncle must be intact for these receptors to affect ventilatory changes in response to elevated CO2 concentrations. The receptors are capable of mediating a ventilatory response to CO2 concentrations lower than those found in either expired air or in confined spaces such as occupied burrows. 4. The discrepancies in the ventilatory responses of lizards and snakes to inspired CO2 reported in past experiments may be partially explained by the presence of nasal or vomeronasal CO2-sensitive receptors.

  17. Inhomogeneity of ventilatory unit volume and its effects on reactive gas uptake

    SciTech Connect

    Mercer, R.R.; Anjilvel, S.; Miller, F.J.; Crapo, J.D. )

    1991-05-01

    This study addressed the question of whether variations in the volume of alveoli and alveolar ducts forming single units of ventilation can significantly influence the distribution and uptake of inspired reactive gases. Quantitative serial section analyses of vascular perfusion-fixed rat lungs were used to determine the anatomic dead space proximal to specific ventilatory units as well as the gas volume of these ventilatory units. Three reconstructions, each consisting of ventilatory units distal to a specific bronchus, were carried out. The number of ventilatory units for each reconstruction varied from 26 to 71. The average ventilatory unit volume for the three reconstructions (0.53 {plus minus} .03 (SE) mm3) was not significantly different from measurements based on random sampling. The distribution of ventilatory unit volume was diverse, with 15% of the population having a volume less than 0.3 mm3 and 9% of the population having a volume greater than 1.0 mm3. For a gas of relatively low reactivity (e.g., oxygen) the predicted oxygen uptake per unit surface area did not vary significantly between ventilatory units. The predicted oxygen uptake was approximately 92% of the uptake in the absence of gradients in oxygen concentration between ventilatory units. For a highly reactive gas (e.g., ozone), the predicted uptake per unit surface area in the proximal portions of larger ventilatory units was significantly greater than the average uptake. These results suggest that focal areas of injury likely result from exposure to inhaled reactive gases.

  18. Posthypoxic ventilatory decline during NREM sleep: influence of sleep apnea.

    PubMed

    Omran, Amal M; Aboubakr, Salah E; Aboussouan, Loutfi S; Pierchala, Lisa; Badr, M Safwan

    2004-06-01

    We wished to determine the severity of posthypoxic ventilatory decline in patients with sleep apnea relative to normal subjects during sleep. We studied 11 men with sleep apnea/hypopnea syndrome and 11 normal men during non-rapid eye movement sleep. We measured EEG, electrooculogram, arterial O(2) saturation, and end-tidal P(CO2). To maintain upper airway patency in patients with sleep apnea, nasal continuous positive pressure was applied at a level sufficient to eliminate apneas and hypopneas. We compared the prehypoxic control (C) with posthypoxic recovery breaths. Nadir minute ventilation in normal subjects was 6.3 +/- 0.5 l/min (83.8 +/- 5.7% of room air control) vs. 6.7 +/- 0.9 l/min, 69.1 +/- 8.5% of room air control in obstructive sleep apnea (OSA) patients; nadir minute ventilation (% of control) was lower in patients with OSA relative to normal subjects (P < 0.05). Nadir tidal volume was 0.55 +/- 0.05 liter (80.0 +/- 6.6% of room air control) in OSA patients vs. 0.42 +/- 0.03 liter, 86.5 +/- 5.2% of room air control in normal subjects. In addition, prolongation of expiratory time (Te) occurred in the recovery period. There was a significant difference in Te prolongation between normal subjects (2.61 +/- 0.3 s, 120 +/- 11.2% of C) and OSA patients (5.6 +/- 1.5 s, 292 +/- 127.6% of C) (P < 0.006). In conclusion, 1) posthypoxic ventilatory decline occurred after termination of hypocapnic hypoxia in normal subjects and patients with sleep apnea and manifested as decreased tidal volume and prolongation of Te; and 2) posthypoxic ventilatory prolongation of Te was more pronounced in patients with sleep apnea relative to normal subjects. PMID:14990552

  19. Ventilatory effects of atenolol and bevantolol in asthma.

    PubMed

    Lammers, J W; Folgering, H T; van Herwaarden, C L

    1985-10-01

    The cardioequipotency of 400 mg bevantolol and 100 mg atenolol was determined by measuring the exercise heart rate in healthy subjects. The beta-blockers were then used in these doses to investigate their ventilatory effects in patients with asthma. The effects of both drugs on forced expiratory flow parameters for large and small airways were assessed at rest and during and after exercise. A dose-response curve was then plotted after inhalation of the beta 2-adrenoceptor agonist terbutaline. Bevantolol significantly decreased the forced expiratory volume in 1 second (FEV1) and the peak expiratory flow rate (PEFR) at rest, while there was no such change with placebo or atenolol. Both beta-blockers decreased the maximal expiratory flow rates at 50% of forced vital capacity (MEF50) and after expiration of 75% of the forced vital capacity (MEF25) at rest; the decrease was larger after bevantolol than after atenolol. During atenolol there was a decrease in FEV1 and in PEFR (P less than 0.01) 15 minutes after exercise in comparison with preexercise values. There was no significant difference between pre- and postexercise values of MEF50 and MEF25 during atenolol dosing. After bevantolol there was only a small change in PEFR after exercise, probably because of the low preexercise values of the ventilatory indices with this drug. Inhalation of terbutaline up to a dose of 2 mg significantly improved all ventilatory indices measured, but with bevantolol the values after 2 mg inhaled terbutaline were lower than the initial values.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Ventilatory endurance in athletes and non-athletes.

    PubMed

    Martin, B J; Stager, J M

    1981-01-01

    Do the ventilatory muscles (VM) of normal persons become fatigued while high ventilation is maintained during strenuous exercise? If so, then one effect of the intense training performed by endurance athletes should be an increase in VM endurance. To investigate this possibility, eight female endurance-athletes and eight female non-athletes were compared in studies of both short-term and long-term maximal ventilation. The two groups were matched for age, body size, and vital capacity. While athletes and non-athletes had similar short-term maximal ventilation (12-s MVV), the athletes displayed greater ventilatory endurance on two-long-term breathing tests. In the first, ventilation was increased 30 1/min every 4 min. Before exhaustion, athletes reached a ventilation that was a significantly greater fraction of their 12-s MVV (75% vs 67%, P less than 0.01), than did non-athletes. Although the energy cost (VO2) of submaximal levels of ventilation was identical in the two groups, athletes reached a significantly greater peak VO2 during this progressive test (P less than 0.05). In the second test of ventilatory endurance, 80% of the 12-s MVV was sustained until exhaustion. Endurance times averaged 11 min for athletes and 3 min for non-athletes (P less than 0.01). While these results do not rule out the possibility of genetic predisposition to high VM endurance in athletes, they are consistent with the possibility that VM training may occur in normal persons during forms of endurance exercise training.

  1. Ventilatory oscillations at exercise: effects of hyperoxia, hypercapnia, and acetazolamide

    PubMed Central

    Hermand, Eric; Lhuissier, François J; Larribaut, Julie; Pichon, Aurélien; Richalet, Jean-Paul

    2015-01-01

    Periodic breathing has been found in patients with heart failure and sleep apneas, and in healthy subjects in hypoxia, during sleep and wakefulness, at rest and, recently, at exercise. To unravel the cardiorespiratory parameters liable to modulate the amplitude and period of ventilatory oscillations, 26 healthy subjects were tested under physiological (exercise) and environmental (hypoxia, hyperoxia, hyperoxic hypercapnia) stresses, and under acetazolamide (ACZ) treatment. A fast Fourier transform spectral analysis of breath-by-breath ventilation evidenced an increase in peak power under hypercapnia (vs. normoxia and hyperoxia, P < 0.001) and a decrease under ACZ (vs. placebo, P < 0.001), whereas it was not modified in hyperoxia. period was shortened by exercise in all conditions (vs. rest, P < 0.01) and by hypercapnia (vs. normoxia, P < 0.05) but remained unchanged under ACZ (vs. placebo). peak power was positively related to cardiac output () and in hyperoxia (P < 0.01), in hypercapnia (P < 0.001) and under ACZ (P < 0.001). period was negatively related to and in hyperoxia (P < 0.01 and P < 0.001, respectively), in hypercapnia (P < 0.05 and P < 0.01, respectively) and under ACZ (P < 0.05 and P < 0.01, respectively). Total respiratory cycle time was the main factor responsible for changes in period. In conclusion, exercise, hypoxia, and hypercapnia increase ventilatory oscillations by increasing and , whereas ACZ decreases ventilatory instability in part by a contrasting action on O2 and CO2 sensing. An intrinsic oscillator might modulate ventilation through a complex system where peripheral chemoreflex would play a key role. PMID:26109194

  2. Ventilatory response to exercise in diabetic subjects with autonomic neuropathy.

    PubMed

    Tantucci, C; Bottini, P; Dottorini, M L; Puxeddu, E; Casucci, G; Scionti, L; Sorbini, C A

    1996-11-01

    We have used diabetic autonomic neuropathy as a model of chronic pulmonary denervation to study the ventilatory response to incremental exercise in 20 diabetic subjects, 10 with (Dan+) and 10 without (Dan-) autonomic dysfunction, and in 10 normal control subjects. Although both Dan+ and Dan- subjects achieved lower O2 consumption and CO2 production (VCO2) than control subjects at peak of exercise, they attained similar values of either minute ventilation (VE) or adjusted ventilation (VE/maximal voluntary ventilation). The increment of respiratory rate with increasing adjusted ventilation was much higher in Dan+ than in Dan- and control subjects (P < 0.05). The slope of the linear VE/VCO2 relationship was 0.032 +/- 0.002, 0.027 +/- 0.001 (P < 0.05), and 0.025 +/- 0.001 (P < 0.001) ml/min in Dan+, Dan-, and control subjects, respectively. Both neuromuscular and ventilatory outputs in relation to increasing VCO2 were progressively higher in Dan+ than in Dan- and control subjects. At peak of exercise, end-tidal PCO2 was much lower in Dan+ (35.9 +/- 1.6 Torr) than in Dan- (42.1 +/- 1.7 Torr; P < 0.02) and control (42.1 +/- 0.9 Torr; P < 0.005) subjects. We conclude that pulmonary autonomic denervation affects ventilatory response to stressful exercise by excessively increasing respiratory rate and alveolar ventilation. Reduced neural inhibitory modulation from sympathetic pulmonary afferents and/or increased chemosensitivity may be responsible for the higher inspiratory output.

  3. Incorporating inheritance into models for understanding ventilatory behavior.

    PubMed

    Strohl, K P; Subramanian, S; Han, F; Principe, K; Dick, T E

    2001-01-01

    Ventilation and its components (frequency and tidal volume) appear to be determined to a significant extent by inheritance. Gene manipulation, gene identification, and functional genomics now offer powerful tools to identify the strength and mode of inheritance for ventilatory behavior under steady-state and non-steady-state conditions, in health and in disease. Conscious integration of genetic principles into existing explanatory models may increase the likelihood of detecting traits that correlate with protein systems responsible for the structures and the functional components of respiration.

  4. Ventilatory response of rabbits and goats to chronic progesterone administration.

    PubMed

    Smith, C A; Kellogg, R H

    1980-03-01

    We assessed the ventilatory response to chronic progesterone administration of 37 male rabbits and 4 castrated male goats. Rabbits, in response to 2.72 mg.kg-1.day-1 of progesterone, did not chronically hyperventilate as measured by changes in CSF [HCO-3]. Two goats given 10 mg/kg/day of progesterone by intramuscular injection, alone or in combination with estradiol or testosterone, manifested no convincing ventilatory changes. Two goats were given progesterone in the form of progesterone-containing Silastic implants. Serum progesterone levels of 8-27 ng/ml were maintained over the course of 45 days. The hyperventilation in these goats, unlike that of man, was slow to develop (8-15 days), slow to decay (10-30 days), and relatively small (resting PETCO2 fell 3-5 mm Hg relative to control); and there was no change in slope of the CO2 response curves. We conclude that goats and rabbits do not respond to progesterone like man, and therefore are not good models with which to study the mechanism(s) by which progesterone produces hyperventilation in man. PMID:7384660

  5. Ventilatory Efficiency in Children and Adolescents: A Systematic Review

    PubMed Central

    Parazzi, Paloma Lopes Francisco; Marson, Fernando Augusto de Lima; Ribeiro, Maria Angela Gonçalves de Oliveira; Schivinski, Camila Isabel Santos; Ribeiro, Jose Dirceu

    2015-01-01

    Introduction. The index of ventilatory efficiency (VE/VCO2) obtained by the progressive exercise test has been considered the gold standard in the prognosis of adults with heart failure, but few studies have evaluated this approach in children. Objective. To verify the scientific evidence about the VE/VCO2 in pediatric and adolescents patients. Methods. A systematic literature review was carried out using the key words VE/VCO2, children, and adolescents using the PEDro and PubMed/MedLine databases. Clinical trials published from 1987 to 2014, including children, adolescents, and young adults up to 25 years, addressing the VE/VCO2 index as a method of evaluation, monitoring, and prognosis were considered. Results. Initially, 95 articles were found; 12 were excluded as the title/abstract did not contain the VE/VCO2 index or because they included patients greater than 25 years of age. From the remaining 83, 58 were repeated between the databases. The final sample consisted of 32 studies including healthy children and children with respiratory and other diseases. Conclusion. There are few studies involving cardiorespiratory assessment by ventilatory efficiency. The studies highlight the fact that high VE/VCO2 values are associated with a worse prognosis of patients due to the relationship with the decrease in pulmonary perfusion and cardiac output. PMID:26063959

  6. Origin of the unique ventilatory apparatus of turtles.

    PubMed

    Lyson, Tyler R; Schachner, Emma R; Botha-Brink, Jennifer; Scheyer, Torsten M; Lambertz, Markus; Bever, G S; Rubidge, Bruce S; de Queiroz, Kevin

    2014-11-07

    The turtle body plan differs markedly from that of other vertebrates and serves as a model system for studying structural and developmental evolution. Incorporation of the ribs into the turtle shell negates the costal movements that effect lung ventilation in other air-breathing amniotes. Instead, turtles have a unique abdominal-muscle-based ventilatory apparatus whose evolutionary origins have remained mysterious. Here we show through broadly comparative anatomical and histological analyses that an early member of the turtle stem lineage has several turtle-specific ventilation characters: rigid ribcage, inferred loss of intercostal muscles and osteological correlates of the primary expiratory muscle. Our results suggest that the ventilation mechanism of turtles evolved through a division of labour between the ribs and muscles of the trunk in which the abdominal muscles took on the primary ventilatory function, whereas the broadened ribs became the primary means of stabilizing the trunk. These changes occurred approximately 50 million years before the evolution of the fully ossified shell.

  7. HIF-1 and ventilatory acclimatization to chronic hypoxia

    PubMed Central

    Powell, Frank L.; Fu, Zhenxing

    2008-01-01

    Ventilatory acclimatization to hypoxia (VAH) is a time-dependent increase in ventilation and ventilatory O2-sensitivity that involves plasticity in carotid body chemoreceptors and CNS respiratory centers. Hypoxia inducible factor-1α (HIF-1α) controls the expression of several genes that increase physiological O2 supply. Studies using transgenic mice show HIF-1α expression in the carotid bodies and CNS with chronic sustained and intermittent hypoxia is important for VAH. Other O2-sensitive transcription factors such as HIF-2α may be important for VAH by reducing metabolic O2 demands also. Specific gene targets of HIF-1α shown to be involved in VAH include erythropoietin, endothelin-1, neuronal nitric oxide synthase and tyrosine hydroxylase. Other HIF-1α targets that may be involved in VAH include vascular endothelial growth factor, heme oxygenase 1 and cytoglobin. Interactions between these multiple pathways and feedback control of HIF-1α expression from some of the targets support a complex and powerful role for HIF-1α in neural plasticity of physiological control circuits with chronic hypoxia. PMID:18708172

  8. Ventilatory response to exercise of elite soccer players

    PubMed Central

    2014-01-01

    Background The purpose of this study was to evaluate the role of ventilatory parameters in maximal exercise performance in elite soccer players. Methods From September 2009 to December 2012, 90 elite soccer players underwent evaluation of lung function test and ergospirometry by means of an incremental symptom-limited treadmill test. Results were analyzed according to i) maximal exercise velocity performed (Hi-M: high-performers, >18.65 km/h; Lo-M: low-performers, <18.65 km/h) and ii) usual role in the team. Results Hi-M showed higher peak minute ventilation (V˙Epeak: 158.3 ± 19.5 vs 148.0 ± 18.54 L/min, p = 0.0203), and forced expiratory volume at first second (5.28 ± 0.50 vs 4.89 ± 0.52 liters, p < 0.001) than Lo-M, independently of playing role. Moreover, a significant correlation between peak oxygen uptake and V˙E (r = 0.57, p < 0.001) was found. Conclusions Ventilatory response plays a role in the assessment of exercise capacity in elite soccer players. PMID:24694313

  9. Ventilatory control and airway anatomy in obstructive sleep apnea.

    PubMed

    Wellman, Andrew; Jordan, Amy S; Malhotra, Atul; Fogel, Robert B; Katz, Eliot S; Schory, Karen; Edwards, Jill K; White, David P

    2004-12-01

    Ventilatory instability may play an important role in the pathogenesis of obstructive sleep apnea. We hypothesized that the influence of ventilatory instability in this disorder would vary depending on the underlying collapsibility of the upper airway. To test this hypothesis, we correlated loop gain with apnea-hypopnea index during supine, nonrapid eye movement sleep in three groups of patients with obstructive sleep apnea based on pharyngeal closing pressure: negative pressure group (pharyngeal closing pressure less than -1 cm H(2)O), atmospheric pressure group (between -1 and +1 cm H(2)O), and positive pressure group (greater than +1 cm H(2)O). Loop gain was measured by sequentially increasing proportional assist ventilation until periodic breathing developed, which occurred in 24 of 25 subjects. Mean loop gain for all three groups was 0.37 +/- 0.11. A significant correlation was found between loop gain and apnea-hypopnea index in the atmospheric group only (r = 0.88, p = 0.0016). We conclude that loop gain has a substantial impact on apnea severity in certain patients with sleep apnea, particularly those with a pharyngeal closing pressure near atmospheric.

  10. "Optimal" application of ventilatory assist in Cheyne-Stokes respiration: a simulation study.

    PubMed

    Khoo, M C; Benser, M E

    2005-01-01

    Although a variety of ventilator therapies have been employed to treat Cheyne-Stokes respiration (CSR), these modalities do not completely eliminate CSR. As well, most current strategies require that ventilatory assist be provided continuously. We used a computer model of the respiratory control system to determine whether a ventilatory assist strategy could be found that would substantially reduce the severity of CSR while minimizing the application of positive airway pressure. We assessed the effects of different levels of ventilatory assist applied during breaths that fell below selected hypopneic thresholds. These could be applied during the descending, ascending, or both phases of the CSR cycle. We found that ventilatory augmentation equal to 30-40% of eupneic drive, applied whenever ventilation fell below 70% of the eupneic level during the ascending or descending-and-ascending phases of CSR led to the greatest regularization of breathing with minimal ventilator intervention. Application of ventilatory assist during the descending phase produced little effect. PMID:17281585

  11. Acute lung injury following exposure to nitric acid

    PubMed Central

    Jayalakshmi, T. K.; Shah, Samir; Lobo, Ivona; Uppe, Abhay; Mehta, Ankur

    2009-01-01

    We present a series of three cases of survival following inhalation of nitric acid fumes, which resulted in acute respiratory distress. Inhalation of nitric acid fumes and its decomposition gases such as nitrogen dioxide results in delayed onset of acute respiratory distress syndrome. Intensive respiratory management, ventilatory support, and steroids can help in survival. PMID:20532002

  12. Effects of dibutyryl cyclic adenosine monophosphate on hypercapnic depression of diaphragmatic contractility in pentobarbital-anesthetized dogs

    PubMed Central

    Fujii, Yoshitaka; Uemura, Aki

    2010-01-01

    Background: Hypercapnia is associated with diaphragm muscle dysfunction that causes a reduction of diaphragmatic force generated for a constant elective myographic activity. No published data are available concerning hypercapnic depression of diaphragmatic contractility during dibutyryl cyclic adenosine monophospate (DBcAMP) administration. Objective: The aim of this study was to assess the effects of DBcAMP on hypercapnic depression of diaphragmatic contractility in pentobarbital-anesthetized dogs. Methods: This experimental study was conducted from July to December 2008 at the Department of Anesthesiology, Institute of Clinical Medicine, University of Tsukuba, Tsukuba, Japan. Adult (aged >5 years) mongrel dogs weighing 10 to 15 kg were randomly divided into 3 equal groups. Hypercapnia (80–90 mm Hg) was induced with 10% carbon dioxide added to the inspired gas. When hypercapnia was established, group 1 was infused with low-dose DBcAMP (0.05 mg/kg/min); group 2 was infused with high-dose DBcAMP (0.2 mg/kg/min); and group 3 received placebo (saline). Study drug was administered intravenously for 60 minutes. Diaphragmatic contractility was assessed by transdiaphragmatic pressure (Pdi) at baseline, induction of hypercapnia, and study drug administration. Results: Twenty-one dogs were divided into 3 groups of 7. There were no significant differences observed at baseline. In the presence of hypercapnia, Pdi (mean [SD], cm H2O) at low- (20-Hz) and high-frequency (100-Hz) stimulation was significantly decreased from baseline in each group (all, P = 0.001). In groups 1 and 2, Pdi at both stimuli was significantly increased during DBcAMP administration compared with hypercapnia-induced values (group 1: 20-Hz, 13.5 [2.2] vs 15.0 [2.4], respectively, P = 0.001, 100-Hz, 21.2 [1.6] vs 22.5 [1.6], P = 0.001; group 2: 20-Hz, 13.7 [1.4] vs 19.2 [1.7], P = 0.001, 100-Hz, 21.0 [2.4] vs 27.2 [2.5], P = 0.001). The Pdi at both stimuli during DBcAMP administration was significantly

  13. Metabolic acidosis may be as protective as hypercapnic acidosis in an ex-vivo model of severe ventilator-induced lung injury: a pilot study

    PubMed Central

    2011-01-01

    Background There is mounting experimental evidence that hypercapnic acidosis protects against lung injury. However, it is unclear if acidosis per se rather than hypercapnia is responsible for this beneficial effect. Therefore, we sought to evaluate the effects of hypercapnic (respiratory) versus normocapnic (metabolic) acidosis in an ex vivo model of ventilator-induced lung injury (VILI). Methods Sixty New Zealand white rabbit ventilated and perfused heart-lung preparations were used. Six study groups were evaluated. Respiratory acidosis (RA), metabolic acidosis (MA) and normocapnic-normoxic (Control - C) groups were randomized into high and low peak inspiratory pressures, respectively. Each preparation was ventilated for 1 hour according to a standardized ventilation protocol. Lung injury was evaluated by means of pulmonary edema formation (weight gain), changes in ultrafiltration coefficient, mean pulmonary artery pressure changes as well as histological alterations. Results HPC group gained significantly greater weight than HPMA, HPRA and all three LP groups (P = 0.024), while no difference was observed between HPMA and HPRA groups regarding weight gain. Neither group differ on ultrafiltration coefficient. HPMA group experienced greater increase in the mean pulmonary artery pressure at 20 min (P = 0.0276) and 40 min (P = 0.0012) compared with all other groups. Histology scores were significantly greater in HP vs. LP groups (p < 0.001). Conclusions In our experimental VILI model both metabolic acidosis and hypercapnic acidosis attenuated VILI-induced pulmonary edema implying a mechanism other than possible synergistic effects of acidosis with CO2 for VILI attenuation. PMID:21486492

  14. Effects of patient-directed music intervention on anxiety and sedative exposure in critically ill patients receiving mechanical-ventilatory support: a randomized clinical trial

    PubMed Central

    Chlan, Linda L.; Weinert, Craig R.; Heiderscheit, Annie; Tracy, Mary Fran; Skaar, Debra J.; Guttormson, Jill L.; Savik, Kay

    2013-01-01

    Context Alternatives to sedative medications are needed to reduce anxiety in mechanically ventilated patients. Music is an integrative therapy without adverse effects that may alleviate the anxiety associated with ventilatory support. Objective To test whether patient-directed, self-initiated music listening can reduce anxiety and sedative exposure during ventilatory support in critically ill patients as compared with 2 control conditions. Design, Setting, and Patients Randomized, controlled trial that enrolled 373 ICU patients from the Minneapolis-St. Paul area receiving acute mechanical-ventilatory support for respiratory failure between September 2006 and March 2011. Patients were Caucasian (86%), female (52%), with mean age 59 (SD 14), APACHE III 63 (SD 21.6), on protocol 5.7 (SD 6.4) days. Intervention Patients (1) self-initiated music listening (patient-directed music; PDM) with preferred selections tailored by a music therapist whenever desired while receiving ventilatory support, (2) self-initiated use of noise-abating headphones (HP), or (3) received usual ICU care (UC). Main Outcome Measures Daily assessments of anxiety (100-mm visual analog scale) and two aggregate measure of sedative exposure (sedation intensity and sedation frequency). Results Mixed-models analysis showed that PDM patients had decreased levels of anxiety compared with the UC group of −19.5 (p=.003). By the fifth study day anxiety was reduced by 36.5% in PDM patients. The interaction between treatment and time showed PDM significantly reduced both measures of sedative exposure. PDM reduced sedation intensity by −.18 (−.36, −.004) points per day and frequency by −.21 (−.37, −.05) points per day compared to UC (p = .05, .01 respectively). PDM reduced sedation frequency by −.18 (−.36, −.004) points per day compared to HP (p = .04). By the fifth study day, PDM patients received two fewer sedative doses (reduction of 38%) and had a reduction of 36% in sedation intensity

  15. Validation and optimization of hypercapnic-calibrated fMRI from oxygen-sensitive two-photon microscopy.

    PubMed

    Gagnon, Louis; Sakadžić, Sava; Lesage, Frédéric; Pouliot, Philippe; Dale, Anders M; Devor, Anna; Buxton, Richard B; Boas, David A

    2016-10-01

    Hypercapnic-calibrated fMRI allows the estimation of the relative changes in the cerebral metabolic rate of oxygen (rCMRO2) from combined BOLD and arterial spin labelling measurements during a functional task, and promises to permit more quantitative analyses of brain activity patterns. The estimation relies on a macroscopic model of the BOLD effect that balances oxygen delivery and consumption to predict haemoglobin oxygenation and the BOLD signal. The accuracy of calibrated fMRI approaches has not been firmly established, which is limiting their broader adoption. We use our recently developed microscopic vascular anatomical network model in mice as a ground truth simulator to test the accuracy of macroscopic, lumped-parameter BOLD models. In particular, we investigate the original Davis model and a more recent heuristic simplification. We find that these macroscopic models are inaccurate using the originally defined parameters, but that the accuracy can be significantly improved by redefining the model parameters to take on new values. In particular, we find that the parameter α that relates cerebral blood-volume changes to cerebral blood-flow changes is significantly smaller than typically assumed and that the optimal value changes with magnetic field strength. The results are encouraging in that they support the use of simple BOLD models to quantify BOLD signals, but further work is needed to understand the physiological interpretation of the redefined model parameters.This article is part of the themed issue 'Interpreting BOLD: a dialogue between cognitive and cellular neuroscience'.

  16. Validation and optimization of hypercapnic-calibrated fMRI from oxygen-sensitive two-photon microscopy.

    PubMed

    Gagnon, Louis; Sakadžić, Sava; Lesage, Frédéric; Pouliot, Philippe; Dale, Anders M; Devor, Anna; Buxton, Richard B; Boas, David A

    2016-10-01

    Hypercapnic-calibrated fMRI allows the estimation of the relative changes in the cerebral metabolic rate of oxygen (rCMRO2) from combined BOLD and arterial spin labelling measurements during a functional task, and promises to permit more quantitative analyses of brain activity patterns. The estimation relies on a macroscopic model of the BOLD effect that balances oxygen delivery and consumption to predict haemoglobin oxygenation and the BOLD signal. The accuracy of calibrated fMRI approaches has not been firmly established, which is limiting their broader adoption. We use our recently developed microscopic vascular anatomical network model in mice as a ground truth simulator to test the accuracy of macroscopic, lumped-parameter BOLD models. In particular, we investigate the original Davis model and a more recent heuristic simplification. We find that these macroscopic models are inaccurate using the originally defined parameters, but that the accuracy can be significantly improved by redefining the model parameters to take on new values. In particular, we find that the parameter α that relates cerebral blood-volume changes to cerebral blood-flow changes is significantly smaller than typically assumed and that the optimal value changes with magnetic field strength. The results are encouraging in that they support the use of simple BOLD models to quantify BOLD signals, but further work is needed to understand the physiological interpretation of the redefined model parameters.This article is part of the themed issue 'Interpreting BOLD: a dialogue between cognitive and cellular neuroscience'. PMID:27574311

  17. Glutamate receptors in the nucleus tractus solitarius contribute to ventilatory acclimatization to hypoxia in rat

    PubMed Central

    Pamenter, Matthew E; Carr, J Austin; Go, Ariel; Fu, Zhenxing; Reid, Stephen G; Powell, Frank L

    2014-01-01

    When exposed to a hypoxic environment the body's first response is a reflex increase in ventilation, termed the hypoxic ventilatory response (HVR). With chronic sustained hypoxia (CSH), such as during acclimatization to high altitude, an additional time-dependent increase in ventilation occurs, which increases the HVR. This secondary increase persists after exposure to CSH and involves plasticity within the circuits in the central nervous system that control breathing. Currently these mechanisms of HVR plasticity are unknown and we hypothesized that they involve glutamatergic synapses in the nucleus tractus solitarius (NTS), where afferent endings from arterial chemoreceptors terminate. To test this, we treated rats held in normoxia (CON) or 10% O2 (CSH) for 7 days and measured ventilation in conscious, unrestrained animals before and after microinjecting glutamate receptor agonists and antagonists into the NTS. In normoxia, AMPA increased ventilation 25% and 50% in CON and CSH, respectively, while NMDA doubled ventilation in both groups (P < 0.05). Specific AMPA and NMDA receptor antagonists (NBQX and MK801, respectively) abolished these effects. MK801 significantly decreased the HVR in CON rats, and completely blocked the acute HVR in CSH rats but had no effect on ventilation in normoxia. NBQX decreased ventilation whenever it was increased relative to normoxic controls; i.e. acute hypoxia in CON and CSH, and normoxia in CSH. These results support our hypothesis that glutamate receptors in the NTS contribute to plasticity in the HVR with CSH. The mechanism underlying this synaptic plasticity is probably glutamate receptor modification, as in CSH rats the expression of phosphorylated NR1 and GluR1 proteins in the NTS increased 35% and 70%, respectively, relative to that in CON rats. PMID:24492841

  18. Glutamate receptors in the nucleus tractus solitarius contribute to ventilatory acclimatization to hypoxia in rat.

    PubMed

    Pamenter, Matthew E; Carr, J Austin; Go, Ariel; Fu, Zhenxing; Reid, Stephen G; Powell, Frank L

    2014-04-15

    When exposed to a hypoxic environment the body's first response is a reflex increase in ventilation, termed the hypoxic ventilatory response (HVR). With chronic sustained hypoxia (CSH), such as during acclimatization to high altitude, an additional time-dependent increase in ventilation occurs, which increases the HVR. This secondary increase persists after exposure to CSH and involves plasticity within the circuits in the central nervous system that control breathing. Currently these mechanisms of HVR plasticity are unknown and we hypothesized that they involve glutamatergic synapses in the nucleus tractus solitarius (NTS), where afferent endings from arterial chemoreceptors terminate. To test this, we treated rats held in normoxia (CON) or 10% O2 (CSH) for 7 days and measured ventilation in conscious, unrestrained animals before and after microinjecting glutamate receptor agonists and antagonists into the NTS. In normoxia, AMPA increased ventilation 25% and 50% in CON and CSH, respectively, while NMDA doubled ventilation in both groups (P < 0.05). Specific AMPA and NMDA receptor antagonists (NBQX and MK801, respectively) abolished these effects. MK801 significantly decreased the HVR in CON rats, and completely blocked the acute HVR in CSH rats but had no effect on ventilation in normoxia. NBQX decreased ventilation whenever it was increased relative to normoxic controls; i.e. acute hypoxia in CON and CSH, and normoxia in CSH. These results support our hypothesis that glutamate receptors in the NTS contribute to plasticity in the HVR with CSH. The mechanism underlying this synaptic plasticity is probably glutamate receptor modification, as in CSH rats the expression of phosphorylated NR1 and GluR1 proteins in the NTS increased 35% and 70%, respectively, relative to that in CON rats.

  19. Clinical outcomes of patients requiring ventilatory support in Brazilian intensive care units: a multicenter, prospective, cohort study

    PubMed Central

    2013-01-01

    Introduction Contemporary information on mechanical ventilation (MV) use in emerging countries is limited. Moreover, most epidemiological studies on ventilatory support were carried out before significant developments, such as lung protective ventilation or broader application of non-invasive ventilation (NIV). We aimed to evaluate the clinical characteristics, outcomes and risk factors for hospital mortality and failure of NIV in patients requiring ventilatory support in Brazilian intensive care units (ICU). Methods In a multicenter, prospective, cohort study, a total of 773 adult patients admitted to 45 ICUs over a two-month period requiring invasive ventilation or NIV for more than 24 hours were evaluated. Causes of ventilatory support, prior chronic health status and physiological data were assessed. Multivariate analysis was used to identifiy variables associated with hospital mortality and NIV failure. Results Invasive MV and NIV were used as initial ventilatory support in 622 (80%) and 151 (20%) patients. Failure with subsequent intubation occurred in 54% of NIV patients. The main reasons for ventilatory support were pneumonia (27%), neurologic disorders (19%) and non-pulmonary sepsis (12%). ICU and hospital mortality rates were 34% and 42%. Using the Berlin definition, acute respiratory distress syndrome (ARDS) was diagnosed in 31% of the patients with a hospital mortality of 52%. In the multivariate analysis, age (odds ratio (OR), 1.03; 95% confidence interval (CI), 1.01 to 1.03), comorbidities (OR, 2.30; 95% CI, 1.28 to 3.17), associated organ failures (OR, 1.12; 95% CI, 1.05 to 1.20), moderate (OR, 1.92; 95% CI, 1.10 to 3.35) to severe ARDS (OR, 2.12; 95% CI, 1.01 to 4.41), cumulative fluid balance over the first 72 h of ICU (OR, 2.44; 95% CI, 1.39 to 4.28), higher lactate (OR, 1.78; 95% CI, 1.27 to 2.50), invasive MV (OR, 2.67; 95% CI, 1.32 to 5.39) and NIV failure (OR, 3.95; 95% CI, 1.74 to 8.99) were independently associated with hospital mortality

  20. Alveolar recruitment maneuver and perioperative ventilatory support in obese patients undergoing abdominal surgery

    PubMed Central

    Forgiarini Júnior, Luiz Alberto; Rezende, Juliana Castilhos; Forgiarini, Soraia Genebra Ibrahim

    2013-01-01

    The development of abdominal surgery represents an alternative therapy for the morbidly obese; however, patients undergoing this surgical procedure often experience postoperative pulmonary complications. The use of alveolar recruitment maneuvers and/or perioperative ventilatory strategies is a possible alternative to reduce these complications, focusing on the reduction of postoperative pulmonary complications. In this review, the benefits of perioperative ventilatory strategies and the implementation of alveolar recruitment maneuvers in obese patients undergoing abdominal surgery are described. PMID:24553513

  1. Distribution of injury and microdosimetry of ozone in the ventilatory unit of the rat

    SciTech Connect

    Pinkerton, K.E.; Mercer, R.R.; Plopper, C.G.; Crapo, J.D. )

    1992-09-01

    The distribution of ozone-induced injury across ventilatory units of the lungs was determined and compared with the predicted distribution of ozone dose across the same units to evaluate dose-response relationships. Sprague-Dawley rats were exposed to either 0.98 ppm ozone 8 h/day for 90 days or to filtered air only. En bloc microdissection was used to identify and isolate in longitudinal profile the bronchiole-alveolar duct junction, first pair of alveolar duct generations, and intervening bifurcation ridge. The first alveolar outpocketing along the bronchiolar wall of each isolation was used to identify the center of a series of concentric arcs radiating outward at 100-microns intervals across each ventilatory unit. The intercept lengths of each arc with the tissue of alveolar septal tips (edges) and alveolar walls were measured and expressed as a function of distance into the ventilatory unit. Relative ozone dose across the ventilatory unit was estimated using the geometry of the tracheobronchial tree and the volume and surface area distribution within individual ventilatory units. This mathematical model of ozone dose demonstrated a high degree of correlation to this measured tissue injury response. The findings of this study demonstrate that microdosimetry and microtoxicology can be used to determine dose-response relationships within the ventilatory unit and to assess questions of tissue sensitivity in ozone-induced lung injury.

  2. Liquid extracorporeal carbon dioxide removal: use of THAM (tris-hydroxymethyl aminomethane) coupled to hemofiltration to control hypercapnic acidosis in a porcine model of protective mechanical ventilation

    PubMed Central

    Tapia, Pablo; Lillo, Felipe; Soto, Dagoberto; Escobar, Leslie; Simon, Felipe; Hernández, Karina; Alegría, Leyla; Bruhn, Alejandro

    2016-01-01

    A promising approach to facilitate protective mechanical ventilation is the use of extracorporeal CO2 removal techniques. Several strategies based on membrane gas exchangers have been developed. However, these techniques are still poorly available. The goal of this study was to assess the efficacy and safety of THAM infusion coupled to hemofiltration for the management of hypercapnic acidosis. A severe respiratory acidosis was induced in seven anesthetized pigs. Five of them were treated with THAM 8-mmol·kg-1·h-1 coupled to hemofiltration (THAM+HF group) at 100 mL·kg-1·h-1. After 18-hours of treatment the THAM infusion was stopped but hemofiltration was kept on until 24-hours. The 2 other animals were treated with THAM but without hemofiltration. After 1-hour of treatment in THAM+HF, PaCO2 rapidly decreased from a median of 89.0 (IQR) (80.0, 98.0) to 71.3 (65.8, 82.0) mmHg (P<0.05), while pH increased from 7.12 (7.01, 7.15) to 7.29 (7.27, 7.30) (P<0.05). Thereafter PaCO2 remained stable between 60-70 mmHg, while pH increased above 7.4. After stopping THAM at 18 hours of treatment a profound rebound effect was observed with severe hypercapnic acidosis. The most important side effect we observed was hyperosmolality, which reached a maximum of 330 (328, 332) mOsm·kg H2O-1 at T18. The animals treated only with THAM developed severe hypercapnia, despite the fact that pH returned to normal values, and died after 12 hours. Control-group had an uneven evolution until the end of the experiment. A combined treatment with THAM coupled to hemofiltration may be an effective treatment to control severe hypercapnic acidosis.

  3. Liquid extracorporeal carbon dioxide removal: use of THAM (tris-hydroxymethyl aminomethane) coupled to hemofiltration to control hypercapnic acidosis in a porcine model of protective mechanical ventilation.

    PubMed

    Tapia, Pablo; Lillo, Felipe; Soto, Dagoberto; Escobar, Leslie; Simon, Felipe; Hernández, Karina; Alegría, Leyla; Bruhn, Alejandro

    2016-01-01

    A promising approach to facilitate protective mechanical ventilation is the use of extracorporeal CO2 removal techniques. Several strategies based on membrane gas exchangers have been developed. However, these techniques are still poorly available. The goal of this study was to assess the efficacy and safety of THAM infusion coupled to hemofiltration for the management of hypercapnic acidosis. A severe respiratory acidosis was induced in seven anesthetized pigs. Five of them were treated with THAM 8-mmol·kg(-1)·h(-1) coupled to hemofiltration (THAM+HF group) at 100 mL·kg(-1)·h(-1). After 18-hours of treatment the THAM infusion was stopped but hemofiltration was kept on until 24-hours. The 2 other animals were treated with THAM but without hemofiltration. After 1-hour of treatment in THAM+HF, PaCO2 rapidly decreased from a median of 89.0 (IQR) (80.0, 98.0) to 71.3 (65.8, 82.0) mmHg (P<0.05), while pH increased from 7.12 (7.01, 7.15) to 7.29 (7.27, 7.30) (P<0.05). Thereafter PaCO2 remained stable between 60-70 mmHg, while pH increased above 7.4. After stopping THAM at 18 hours of treatment a profound rebound effect was observed with severe hypercapnic acidosis. The most important side effect we observed was hyperosmolality, which reached a maximum of 330 (328, 332) mOsm·kg H2O(-1) at T18. The animals treated only with THAM developed severe hypercapnia, despite the fact that pH returned to normal values, and died after 12 hours. Control-group had an uneven evolution until the end of the experiment. A combined treatment with THAM coupled to hemofiltration may be an effective treatment to control severe hypercapnic acidosis.

  4. Respiratory and ventilatory effects of methadone in healthy women.

    PubMed

    Olsen, G D; Wilson, J E; Robertson, G E

    1981-03-01

    The effects of oral methadone on respiration, ventilation, pupillary diameter, and plasma concentrations of estrone, estradiol, and progesterone were investigated in healthy nonpregnant women, 21 to 29 yr old. All women were in the follicular phase of the menstrual cycle. The study design was a randomized, double-blind, placebo-controlled trial. Six women received 15 mg methadone . HCl, and six received placebo. Alveolar ventilation and oxygen consumption before treatments correlated with plasma progesterone concentration (r2 = 0.85 and 0.68) but the slope and x-intercept of the ventilatory response to carbon dioxide curve did not. Female sex steroids in plasma were not affected by methadone. Mean elimination half-life of methadone from serum was 19 hr. Methadone-induced respiratory depression and miosis lasted more than 48 hr. The intensity of these changes was a linear function of the logarithm of the serum methadone concentration. Plasma progesterone concentration is an important determinant of resting ventilation and metabolism in the follicular phase of the menstrual cycle but endogenous progesterone does not protect women from the respiratory depressant effects of methadone. PMID:6781808

  5. Ancestry explains the blunted ventilatory response to sustained hypoxia and lower exercise ventilation of Quechua altitude natives.

    PubMed

    Brutsaert, Tom D; Parra, Esteban J; Shriver, Mark D; Gamboa, Alfredo; Rivera-Ch, Maria; León-Velarde, Fabiola

    2005-07-01

    Andean high-altitude (HA) natives have a low (blunted) hypoxic ventilatory response (HVR), lower effective alveolar ventilation, and lower ventilation (VE) at rest and during exercise compared with acclimatized newcomers to HA. Despite blunted chemosensitivity and hypoventilation, Andeans maintain comparable arterial O(2) saturation (Sa(O(2))). This study was designed to evaluate the influence of ancestry on these trait differences. At sea level, we measured the HVR in both acute (HVR-A) and sustained (HVR-S) hypoxia in a sample of 32 male Peruvians of mainly Quechua and Spanish origins who were born and raised at sea level. We also measured resting and exercise VE after 10-12 h of exposure to altitude at 4,338 m. Native American ancestry proportion (NAAP) was assessed for each individual using a panel of 80 ancestry-informative molecular markers (AIMs). NAAP was inversely related to HVR-S after 10 min of isocapnic hypoxia (r = -0.36, P = 0.04) but was not associated with HVR-A. In addition, NAAP was inversely related to exercise VE (r = -0.50, P = 0.005) and ventilatory equivalent (VE/Vo(2), r = -0.51, P = 0.004) measured at 4,338 m. Thus Quechua ancestry may partly explain the well-known blunted HVR (10, 35, 36, 57, 62) at least to sustained hypoxia, and the relative exercise hypoventilation at altitude of Andeans compared with European controls. Lower HVR-S and exercise VE could reflect improved gas exchange and/or attenuated chemoreflex sensitivity with increasing NAAP. On the basis of these ancestry associations and on the fact that developmental effects were completely controlled by study design, we suggest both a genetic basis and an evolutionary origin for these traits in Quechua.

  6. Gene transcripts encoding hypoxia-inducible factor (HIF) exhibit tissue- and muscle fiber type-dependent responses to hypoxia and hypercapnic hypoxia in the Atlantic blue crab, Callinectes sapidus.

    PubMed

    Hardy, Kristin M; Follett, Chandler R; Burnett, Louis E; Lema, Sean C

    2012-09-01

    Hypoxia inducible factor (HIF) is a transcription factor that under low environmental oxygen regulates the expression of suites of genes involved in metabolism, angiogenesis, erythropoiesis, immune function, and growth. Here, we isolated and sequenced partial cDNAs encoding hif-α and arnt/hif-β from the Atlantic blue crab, Callinectes sapidus, an estuarine species that frequently encounters concurrent hypoxia (low O(2)) and hypercapnia (elevated CO(2)). We then examined the effects of acute exposure (1h) to hypoxia (H) and hypercapnic hypoxia (HH) on relative transcript abundance for hif-α and arnt/hif-β in different tissues (glycolytic muscle, oxidative muscle, hepatopancreas, gill, and gonads) using quantitative real-time RT-PCR. Our results indicate that hif-α and arnt/hif-β mRNAs were constitutively present under well-aerated normoxia (N) conditions in all tissues examined. Further, H and HH exposure resulted in both tissue-specific and muscle fiber type-specific effects on relative hif-α transcript abundance. In the gill and glycolytic muscle, relative hif-α mRNA levels were significantly lower under H and HH, compared to N, while no change (or a slight increase) was detected in oxidative muscle, hepatopancreas and gonadal tissues. H and HH did not affect relative transcript abundance for arnt/hif-β in any tissue or muscle fiber type. Thus, in crustaceans the HIF response to H and HH appears to involve changes in hif transcript abundance, with variation in hif-α and arnt/hif-β transcriptional dynamics occurring in both a tissue- and muscle fiber type-dependent manner.

  7. Hypoxic ventilatory response in Tac1-/- neonatal mice following exposure to opioids.

    PubMed

    Berner, J; Shvarev, Y; Zimmer, A; Wickstrom, R

    2012-12-01

    Morphine is the dominating analgetic drug used in neonates, but opioid-induced respiratory depression limits its therapeutic use. In this study, we examined acute morphine effects on respiration during intermittent hypoxia in newborn Tac1 gene knockout mice (Tac1-/-) lacking substance P and neurokinin A. In vivo, plethysmography revealed a blunted hypoxic ventilatory response (HVR) in Tac1-/- mice. Morphine (10 mg/kg) depressed the HVR in wild-type animals through an effect on respiratory frequency, whereas it increased tidal volumes in Tac1-/- during hypoxia, resulting in increased minute ventilation. Apneas were reduced during the first hypoxic episode in both morphine-exposed groups, but were restored subsequently in Tac1-/- mice. Morphine did not affect ventilation or apnea prevalence during baseline conditions. In vitro, morphine (50 nM) had no impact on anoxic response of brain stem preparations of either strain. In contrast, it suppressed the inspiratory rhythm during normoxia and potentiated development of posthypoxic neuronal arrest, especially in Tac1-/-. Thus this phenotype has a higher sensitivity to the depressive effects of morphine on inspiratory rhythm generation, but morphine does not modify the reactivity to oxygen deprivation. In conclusion, although Tac1-/- mice are similar to wild-type animals during normoxia, they differed by displaying a reversed pattern with an improved HVR during intermittent hypoxia both in vivo and in vitro. These data suggest that opioids and the substance P-ergic system interact in the HVR, and that reducing the activity in the tachykinin system may alter the respiratory effects of opioid treatment in newborns.

  8. Increased ventilatory response to carbon dioxide in COPD patients following vitamin C administration

    PubMed Central

    Hartmann, Sara E.; Kissel, Christine K.; Szabo, Lian; Walker, Brandie L.; Leigh, Richard; Anderson, Todd J.

    2015-01-01

    Patients with chronic obstructive pulmonary disease (COPD) have decreased ventilatory and cerebrovascular responses to hypercapnia. Antioxidants increase the ventilatory response to hypercapnia in healthy humans. Cerebral blood flow is an important determinant of carbon dioxide/hydrogen ion concentration at the central chemoreceptors and may be affected by antioxidants. It is unknown whether antioxidants can improve the ventilatory and cerebral blood flow response in individuals in whom these are diminished. Thus, we aimed to determine the effect of vitamin C administration on the ventilatory and cerebrovascular responses to hypercapnia during healthy ageing and in COPD. Using transcranial Doppler ultrasound, we measured the ventilatory and cerebral blood flow responses to hyperoxic hypercapnia before and after an intravenous vitamin C infusion in healthy young (Younger) and older (Older) subjects and in moderate COPD. Vitamin C increased the ventilatory response in COPD patients (mean (95% CI) 1.1 (0.9–1.1) versus 1.5 (1.1–2.0) L·min−1·mmHg−1, p<0.05) but not in Younger (2.5 (1.9–3.1) versus 2.4 (1.9–2.9) L·min−1·mmHg−1, p>0.05) or Older (1.3 (1.0–1.7) versus 1.3 (1.0–1.7) L·min−1·mmHg−1, p>0.05) healthy subjects. Vitamin C did not affect the cerebral blood flow response in the young or older healthy subjects or COPD subjects (p>0.05). Vitamin C increases the ventilatory but not cerebrovascular response to hyperoxic hypercapnia in patients with moderate COPD. PMID:27730137

  9. Reducing ventilatory response to carbon dioxide by breathing cold air.

    PubMed

    Burgess, K R; Whitelaw, W A

    1984-05-01

    To study the effect of cooling of nasal receptors on breathing we had 10 normal male volunteers rebreathe through their noses 8% CO2 in oxygen at "warm" (23 to 30 degrees C) and at "cold" (-4 to 10 degrees C) temperatures. In order to further examine the effect of nasal receptors on the control of breathing, 11 subjects had their nasal response to CO2 measured at the warm temperature before and after topical nasal anesthesia. To exclude an increase in nasal resistance as the cause of the reduced response to CO2, 10 subjects had their nasal resistance measured before and after nasal rebreathing of cold 8% CO2 in oxygen. To also exclude increased bronchial resistance, forced expiratory volume in one second (FEV1) was measured in 12 subjects before and after nasal breathing of cold oxygen for 3 min. The mean ventilatory response to CO2 was reduced from 3.0 +/- 1.6 L/min/mmHg to 2.5 +/- 1.1 L/min/mmHg (p less than 0.05) by the cold air. Topical nasal anesthesia increased the response to CO2 at the warm temperature from 2.4 +/- 0.7 to 2.7 +/- 0.9 L/min/mmHg. The effect of nasal breathing of 8% CO2 in oxygen at the cold temperature was to reduce nasal inspiratory resistance at 1 L/s from 4.3 +/- 3.0 cm H2O L/s to 2.6 +/- 1.0 cm H2O L/s (p less than 0.05). Expiratory resistance at 1 L/s fell from 3.7 +/- 1.5 cm H2O L/s to 2.4 +/- 0.7 cm H2O L/s (p less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

  10. Changes in orexinergic immunoreactivity of the piglet hypothalamus and pons after exposure to chronic postnatal nicotine and intermittent hypercapnic hypoxia.

    PubMed

    Hunt, Nicholas J; Russell, Benjamin; Du, Man K; Waters, Karen A; Machaalani, Rita

    2016-06-01

    We recently showed that orexin expression in sudden infant death syndrome (SIDS) infants was reduced by 21% in the hypothalamus and by 40-50% in the pons as compared with controls. Orexin maintains wakefulness/sleeping states, arousal, and rapid eye movement sleep, abnormalities of which have been reported in SIDS. This study examined the effects of two prominent risk factors for SIDS, intermittent hypercapnic hypoxia (IHH) (prone-sleeping) and chronic nicotine exposure (cigarette-smoking), on orexin A (OxA) and orexin B (OxB) expression in piglets. Piglets were randomly assigned to five groups: saline control (n = 7), air control (n = 7), nicotine [2 mg/kg per day (14 days)] (n = 7), IHH (6 min of 7% O2 /8% CO2 alternating with 6-min periods of breathing air, for four cycles) (n = 7), and the combination of nicotine and IHH (N + IHH) (n = 7). OxA/OxB expression was quantified in the central tuberal hypothalamus [dorsal medial hypothalamus (DMH), perifornical area (PeF), and lateral hypothalamus], and the dorsal raphe, locus coeruleus of the pons. Nicotine and N + IHH exposures significantly increased: (i) orexin expression in the hypothalamus and pons; and (ii) the total number of neurons in the DMH and PeF. IHH decreased orexin expression in the hypothalamus and pons without changing neuronal numbers. Linear relationships existed between the percentage of orexin-positive neurons and the area of pontine orexin immunoreactivity of control and exposure piglets. These results demonstrate that postnatal nicotine exposure increases the proportion of orexin-positive neurons in the hypothalamus and fibre expression in the pons, and that IHH exposure does not prevent the nicotine-induced increase. Thus, although both nicotine and IHH are risk factors for SIDS, it appears they have opposing effects on OxA and OxB expression, with the IHH exposure closely mimicking what we recently found in SIDS. PMID:27038133

  11. The effect of combined glutamate receptor blockade in the NTS on the hypoxic ventilatory response in awake rats differs from the effect of individual glutamate receptor blockade

    PubMed Central

    Pamenter, Matthew E.; Nguyen, Jetson; Carr, John A.; Powell, Frank L.

    2014-01-01

    Abstract Ventilatory acclimatization to hypoxia (VAH) increases the hypoxic ventilatory response (HVR) and causes persistent hyperventilation when normoxia is restored, which is consistent with the occurrence of synaptic plasticity in acclimatized animals. Recently, we demonstrated that antagonism of individual glutamate receptor types (GluRs) within the nucleus tractus solitarii (NTS) modifies this plasticity and VAH (J. Physiol. 592(8):1839–1856); however, the effects of combined GluR antagonism remain unknown in awake rats. To evaluate this, we exposed rats to room air or chronic sustained hypobaric hypoxia (CSH, PiO2 = 70 Torr) for 7–9 days. On the experimental day, we microinjected artificial cerebrospinal fluid (ACSF: sham) and then a “cocktail” of the GluR antagonists MK‐801 and DNQX into the NTS. The location of injection sites in the NTS was confirmed by glutamate injections on a day before the experiment and with histology following the experiment. Ventilation was measured in awake, unrestrained rats breathing normoxia or acute hypoxia (10% O2) in 15‐min intervals using barometric pressure plethysmography. In control (CON) rats, acute hypoxia increased ventilation; NTS microinjections of GluR antagonists, but not ACSF, significantly decreased ventilation and breathing frequency in acute hypoxia but not normoxia (P <0.05). CSH increased ventilation in hypoxia and acute normoxia. In CSH‐conditioned rats, GluR antagonists in the NTS significantly decreased ventilation in normoxia and breathing frequency in hypoxia. A persistent HVR after combined GluR blockade in the NTS contrasts with the effect of individual GluR blockade and also with results in anesthetized rats. Our findings support the hypotheses that GluRs in the NTS contribute to, but cannot completely explain, VAH in awake rats. PMID:25107985

  12. The effect of combined glutamate receptor blockade in the NTS on the hypoxic ventilatory response in awake rats differs from the effect of individual glutamate receptor blockade.

    PubMed

    Pamenter, Matthew E; Nguyen, Jetson; Carr, John A; Powell, Frank L

    2014-08-01

    Ventilatory acclimatization to hypoxia (VAH) increases the hypoxic ventilatory response (HVR) and causes persistent hyperventilation when normoxia is restored, which is consistent with the occurrence of synaptic plasticity in acclimatized animals. Recently, we demonstrated that antagonism of individual glutamate receptor types (GluRs) within the nucleus tractus solitarii (NTS) modifies this plasticity and VAH (J. Physiol. 592(8):1839-1856); however, the effects of combined GluR antagonism remain unknown in awake rats. To evaluate this, we exposed rats to room air or chronic sustained hypobaric hypoxia (CSH, PiO2 = 70 Torr) for 7-9 days. On the experimental day, we microinjected artificial cerebrospinal fluid (ACSF: sham) and then a "cocktail" of the GluR antagonists MK-801 and DNQX into the NTS. The location of injection sites in the NTS was confirmed by glutamate injections on a day before the experiment and with histology following the experiment. Ventilation was measured in awake, unrestrained rats breathing normoxia or acute hypoxia (10% O2) in 15-min intervals using barometric pressure plethysmography. In control (CON) rats, acute hypoxia increased ventilation; NTS microinjections of GluR antagonists, but not ACSF, significantly decreased ventilation and breathing frequency in acute hypoxia but not normoxia (P < 0.05). CSH increased ventilation in hypoxia and acute normoxia. In CSH-conditioned rats, GluR antagonists in the NTS significantly decreased ventilation in normoxia and breathing frequency in hypoxia. A persistent HVR after combined GluR blockade in the NTS contrasts with the effect of individual GluR blockade and also with results in anesthetized rats. Our findings support the hypotheses that GluRs in the NTS contribute to, but cannot completely explain, VAH in awake rats.

  13. The effect of combined glutamate receptor blockade in the NTS on the hypoxic ventilatory response in awake rats differs from the effect of individual glutamate receptor blockade.

    PubMed

    Pamenter, Matthew E; Nguyen, Jetson; Carr, John A; Powell, Frank L

    2014-08-01

    Ventilatory acclimatization to hypoxia (VAH) increases the hypoxic ventilatory response (HVR) and causes persistent hyperventilation when normoxia is restored, which is consistent with the occurrence of synaptic plasticity in acclimatized animals. Recently, we demonstrated that antagonism of individual glutamate receptor types (GluRs) within the nucleus tractus solitarii (NTS) modifies this plasticity and VAH (J. Physiol. 592(8):1839-1856); however, the effects of combined GluR antagonism remain unknown in awake rats. To evaluate this, we exposed rats to room air or chronic sustained hypobaric hypoxia (CSH, PiO2 = 70 Torr) for 7-9 days. On the experimental day, we microinjected artificial cerebrospinal fluid (ACSF: sham) and then a "cocktail" of the GluR antagonists MK-801 and DNQX into the NTS. The location of injection sites in the NTS was confirmed by glutamate injections on a day before the experiment and with histology following the experiment. Ventilation was measured in awake, unrestrained rats breathing normoxia or acute hypoxia (10% O2) in 15-min intervals using barometric pressure plethysmography. In control (CON) rats, acute hypoxia increased ventilation; NTS microinjections of GluR antagonists, but not ACSF, significantly decreased ventilation and breathing frequency in acute hypoxia but not normoxia (P < 0.05). CSH increased ventilation in hypoxia and acute normoxia. In CSH-conditioned rats, GluR antagonists in the NTS significantly decreased ventilation in normoxia and breathing frequency in hypoxia. A persistent HVR after combined GluR blockade in the NTS contrasts with the effect of individual GluR blockade and also with results in anesthetized rats. Our findings support the hypotheses that GluRs in the NTS contribute to, but cannot completely explain, VAH in awake rats. PMID:25107985

  14. Effect of sleep and sleep deprivation on ventilatory response to bronchoconstriction.

    PubMed

    Ballard, R D; Tan, W C; Kelly, P L; Pak, J; Pandey, R; Martin, R J

    1990-08-01

    To characterize ventilatory responses to bronchoconstriction during sleep and to assess the effect of prior sleep deprivation on ventilatory and arousal responses to bronchoconstriction, bronchoconstriction was induced in eight asthmatic subjects while they were awake, during normal sleep, and during sleep after a 36-h period of sleep deprivation. Each subject was bronchoconstricted with increasing concentrations of aerosolized methacholine while ventilatory patterns and lower airway resistance (Rla) were continually monitored. The asthmatic patients maintained their minute ventilation as Rla increased under all conditions, demonstrating a stable tidal volume with a mild increase in respiratory frequency. Inspiratory drive, as measured by occlusion pressure (P0.1), increased progressively and significantly as Rla increased under all conditions (slopes of P0.1 vs. Rla = 0.249, 0.112, and 0.154 for awake, normal sleep, and sleep after sleep deprivation, respectively, P less than 0.0006). Chemostimuli did not appear to contribute significantly to the observed increases in P0.1. Prior sleep deprivation had no effect on ventilatory and P0.1 responses to bronchoconstriction but did significantly raise the arousal threshold to induced bronchoconstriction. We conclude that ventilatory responses to bronchoconstriction, unlike extrinsic loading, are not imparied by the presence of sleep, nor are they chemically mediated. However, prior sleep deprivation does increase the subsequent arousal threshold.

  15. An examination of exercise mode on ventilatory patterns during incremental exercise.

    PubMed

    Elliott, Adrian D; Grace, Fergal

    2010-10-01

    Both cycle ergometry and treadmill exercise are commonly employed to examine the cardiopulmonary system under conditions of precisely controlled metabolic stress. Although both forms of exercise are effective in elucidating a maximal stress response, it is unclear whether breathing strategies or ventilator efficiency differences exist between exercise modes. The present study examines breathing strategies, ventilatory efficiency and ventilatory capacity during both incremental cycling and treadmill exercise to volitional exhaustion. Subjects (n = 9) underwent standard spirometric assessment followed by maximal cardiopulmonary exercise testing utilising cycle ergometry and treadmill exercise using a randomised cross-over design. Respiratory gases and volumes were recorded continuously using an online gas analysis system. Cycling exercise utilised a greater portion of ventilatory capacity and higher tidal volume at comparable levels of ventilation. In addition, there was an increased mean inspiratory flow rate at all levels of ventilation during cycle exercise, in the absence of any difference in inspiratory timing. Exercising V(E)/VCO₂slope and the lowest V(E)/VCO₂value, was lower during cycling exercise than during the treadmill protocol indicating greater ventilatory efficiency. The present study identifies differing breathing strategies employed during cycling and treadmill exercise in young, trained individuals. Exercise mode should be accounted for when assessing breathing patterns and/or ventilatory efficiency during incremental exercise.

  16. Experimental effects of chloral hydrate in ventilatory response to hypoxia and hypercarbia.

    PubMed

    Hunt, C E; Hazinski, T A; Gora, P

    1982-01-01

    The effect of chloral hydrate (CH)-induced sleep on inspiratory drive has not been systematically assessed. To determine the effects of CH on the ventilatory responses to hypercarbia and to hypoxia, nine unanesthetized adult rabbit with chronic tracheostomy were studied. We compared awake ventilatory measurements before CH to non-REM sleep assessments at 30, 60, 90, and 120 min after administration of 250 mg/kg of CH. There were no significant differences between any of these assessment intervals for respiratory rate, PACO2, PAO2, tidal volume (VT), minute volume, Ti/Ttot, or VT/Ti. Hypercarbic ventilatory response to slopes were not diminished at any of the CH-sleep intervals compared to the awake mean slope. In addition, the ventilatory response to hypoxia at PAO2=70 mm Hg (V70) and the hypoxic response slope demonstrated no significant decrease at any of the CH-sleep intervals. In summary, absence of any significant decrease in either hypercarbic or hypoxic ventilatory response after CH administration indicates absence of any CH effect on chemical inspiratory drive. PMID:6803222

  17. Effects of inspiratory loading on the chaotic dynamics of ventilatory flow in humans.

    PubMed

    Samara, Ziyad; Raux, Mathieu; Fiamma, Marie-Noëlle; Gharbi, Alexandre; Gottfried, Stewart B; Poon, Chi-Sang; Similowski, Thomas; Straus, Christian

    2009-01-01

    Human ventilation at rest exhibits complexity and chaos. The aim of this study was to determine whether suprapontine interferences with the automatic breathing control could contribute to ventilatory chaos. We conducted a post hoc analysis of a previous study performed in awake volunteers exhibiting cortical pre-motor potentials during inspiratory loading. In eight subjects, flow was recorded at rest, while breathing against inspiratory threshold loads (median 21.5 cm H(2)O) and resistive loads (50 cm H(2)Ol(-1)s(-1)) loads, and while inhaling 7% CO(2)-93% O(2). Chaos was identified through noise titration (noise limit, NL) and the sensitivity to initial conditions was assessed through the largest Lyapunov exponent (LLE). Breath-by-breath variability was evaluated using the coefficient of variation of several ventilatory variables. Chaos was consistently present in ventilatory flow recordings, but mechanical loading did not alter NL, LLE, or variability. In contrast, CO(2) altered chaos and reduced variability. In conclusion, inspiratory loading - and any resultant respiratory-related cortical activity - were not associated with changes in ventilatory chaos in this study, arguing against suprapontine contributions to ventilatory complexity. PMID:19013545

  18. Effect of exercise training on ventilatory efficiency in patients with heart disease: a review

    PubMed Central

    Prado, D.M.L.; Rocco, E.A.; Silva, A.G.; Rocco, D.F.; Pacheco, M.T.; Furlan, V.

    2016-01-01

    The analysis of ventilatory efficiency in cardiopulmonary exercise testing has proven useful for assessing the presence and severity of cardiorespiratory diseases. During exercise, efficient pulmonary gas exchange is characterized by uniform matching of lung ventilation with perfusion. By contrast, mismatching is marked by inefficient pulmonary gas exchange, requiring increased ventilation for a given CO2 production. The etiology of increased and inefficient ventilatory response to exercise in heart disease is multifactorial, involving both peripheral and central mechanisms. Exercise training has been recommended as non-pharmacological treatment for patients with different chronic cardiopulmonary diseases. In this respect, previous studies have reported improvements in ventilatory efficiency after aerobic exercise training in patients with heart disease. Against this background, the primary objective of the present review was to discuss the pathophysiological mechanisms involved in abnormal ventilatory response to exercise, with an emphasis on both patients with heart failure syndrome and coronary artery disease. Secondly, special focus was dedicated to the role of aerobic exercise training in improving indices of ventilatory efficiency among these patients, as well as to the underlying mechanisms involved. PMID:27332771

  19. New modes of mechanical ventilation: proportional assist ventilation, neurally adjusted ventilatory assist, and fractal ventilation.

    PubMed

    Navalesi, Paolo; Costa, Roberta

    2003-02-01

    Increased knowledge of the mechanisms that determine respiratory failure has led to the development of new technologies aimed at improving ventilatory treatment. Proportional assist ventilation and neurally adjusted ventilatory assist have been designed with the goal of improving patient-ventilator interaction by matching the ventilator support with the neural output of the respiratory centers. With proportional assist ventilation, the support is continuously readjusted in proportion to the predicted inspiratory effort. Neurally adjusted ventilatory assist is an experimental mode in which the assistance is delivered in proportion to the electrical activity of the diaphragm, assessed by means of an esophageal electrode. Biologically variable (or fractal) ventilation is a new, volume-targeted, controlled ventilation mode aimed at improving oxygenation; it incorporates the breath-to-breath variability that characterizes a natural breathing pattern.

  20. Chemosensitivity, Cardiovascular Risk, and the Ventilatory Response to Exercise in COPD

    PubMed Central

    Stickland, Michael K.; Fuhr, Desi P.; Edgell, Heather; Byers, Brad W.; Bhutani, Mohit; Wong, Eric Y. L.; Steinback, Craig D.

    2016-01-01

    COPD is associated with elevated cardiovascular risk and a potentiated ventilatory response to exercise. Enhanced carotid chemoreceptor (CC) activity/sensitivity is present in other clinical conditions, has been shown to contribute to sympathetic vasoconstrictor outflow, and is predictive of mortality. CC activity/sensitivity, and the resulting functional significance, has not been well examined in COPD. We hypothesized that CC activity/sensitivity would be elevated in COPD, and related to increased pulse wave velocity (a marker of CV risk) and the ventilatory response to exercise. Methods: 30 COPD patients and 10 healthy age-matched controls were examined. Participants performed baseline cardiopulmonary exercise and pulmonary function testing. CC activity was later evaluated by the drop in ventilation with breathing 100% O2, and CC sensitivity was then assessed by the ventilatory response to hypoxia (ΔVE/ΔSpO2). Peripheral arterial stiffness was subsequently evaluated by measurement of pulse wave velocity (PWV) using applanation tonometry while the subjects were breathing room air, and then following chemoreceptor inhibition by breathing 100% O2 for 2 minutes. Results: CC activity, CC sensitivity, PWV and the ventilatory response to exercise were all increased in COPD relative to controls. CC sensitivity was related to PWV; however, neither CC activity nor CC sensitivity was related to the ventilatory response to exercise in COPD. CC inhibition by breathing 100% O2 normalized PWV in COPD, while no effect was observed in controls. Conclusion: CC activity and sensitivity are elevated in COPD, and appear related to cardiovascular risk; however, CC activity/sensitivity does not contribute to the potentiated ventilatory response to exercise. PMID:27355356

  1. A dynamic analysis of the ventilatory response to carbon dioxide inhalation in man.

    PubMed Central

    Bertholon, J F; Carles, J; Eugene, M; Labeyrie, E; Teillac, A

    1988-01-01

    1. The dynamics of the ventilatory response to carbon dioxide inhalation were studied in ten healthy young men using four different inspired fractions of carbon dioxide (FI, CO2) in air (0.015, 0.030, 0.045 and 0.060) successively increasing and decreasing stepwise. 2. Seven such different progressions were performed for each subject and each of seven different durations of the steps (t) ranging between 0.1 (i.e. one ventilatory cycle) and 10 min ('steady-state' conditions). The overall duration of one test (T) was taken as the sum of the seven successive FI, CO2 steps (t) plus one step, t, of air breathing. Thus, the values of T ranged between 0.8 (i.e. eight ventilatory cycles) and 80 min. Three subjects were tested twice. 3. We measured, as a function of T, the magnitude of the loops formed by the curves PA, CO2-VE and the value of the highest ventilatory response (VE max) to each progression. For all ten subjects, both functions had two maxima, one for T values of 2.6 or 8.0 min and one for T values of 24 or 40 min, and one minimum at T equal to 12 min. 4. The same measurements were made on tidal volume-response curves (PA, CO2-VT) and ventilatory frequency-response curves (PA, CO2-f) and yielded the same results except for the ventilatory frequency-response curves, for which we only found a statistically insignificant single maximum for T values of 24 or 40 min. 5. The locations of the maxima in loop magnitude and VE max were similar in duplicate tests in three subjects, whereas the quantitative values of these variables showed wide differences. 6. We compared our results with what is expected from the current linear dynamic model of ventilatory control submitted to the same forcing function: the first maximum in the loop magnitude is predicted by the model, but the second is not. The model shows no peak in the evolution of VE max. 7. We conclude that controlled system dynamics, which are the only ones included in dynamic models of ventilatory control, cannot

  2. An Interdependent Model of Central/Peripheral Chemoreception: Evidence and Implications for Ventilatory Control

    PubMed Central

    Smith, Curtis A.; Forster, Hubert V.; Blain, Grégory M.; Dempsey, Jerome A.

    2010-01-01

    In this review we discuss the implications for ventilatory control of newer evidence suggesting that central and peripheral chemoreceptors are not functionally separate but rather that they are dependent upon one another such that the sensitivity of the medullary chemoreceptors is critically determined by input from the carotid body chemoreceptors and vice versa i.e., they are interdependent. We examine potential interactions of the interdependent central and carotid body (CB) chemoreceptors with other ventilatory-related inputs such as central hypoxia, lung stretch, and exercise. The limitations of current approaches addressing this question are discussed and future studies are suggested. PMID:20206717

  3. Liquid extracorporeal carbon dioxide removal: use of THAM (tris-hydroxymethyl aminomethane) coupled to hemofiltration to control hypercapnic acidosis in a porcine model of protective mechanical ventilation.

    PubMed

    Tapia, Pablo; Lillo, Felipe; Soto, Dagoberto; Escobar, Leslie; Simon, Felipe; Hernández, Karina; Alegría, Leyla; Bruhn, Alejandro

    2016-01-01

    A promising approach to facilitate protective mechanical ventilation is the use of extracorporeal CO2 removal techniques. Several strategies based on membrane gas exchangers have been developed. However, these techniques are still poorly available. The goal of this study was to assess the efficacy and safety of THAM infusion coupled to hemofiltration for the management of hypercapnic acidosis. A severe respiratory acidosis was induced in seven anesthetized pigs. Five of them were treated with THAM 8-mmol·kg(-1)·h(-1) coupled to hemofiltration (THAM+HF group) at 100 mL·kg(-1)·h(-1). After 18-hours of treatment the THAM infusion was stopped but hemofiltration was kept on until 24-hours. The 2 other animals were treated with THAM but without hemofiltration. After 1-hour of treatment in THAM+HF, PaCO2 rapidly decreased from a median of 89.0 (IQR) (80.0, 98.0) to 71.3 (65.8, 82.0) mmHg (P<0.05), while pH increased from 7.12 (7.01, 7.15) to 7.29 (7.27, 7.30) (P<0.05). Thereafter PaCO2 remained stable between 60-70 mmHg, while pH increased above 7.4. After stopping THAM at 18 hours of treatment a profound rebound effect was observed with severe hypercapnic acidosis. The most important side effect we observed was hyperosmolality, which reached a maximum of 330 (328, 332) mOsm·kg H2O(-1) at T18. The animals treated only with THAM developed severe hypercapnia, despite the fact that pH returned to normal values, and died after 12 hours. Control-group had an uneven evolution until the end of the experiment. A combined treatment with THAM coupled to hemofiltration may be an effective treatment to control severe hypercapnic acidosis. PMID:27648139

  4. Liquid extracorporeal carbon dioxide removal: use of THAM (tris-hydroxymethyl aminomethane) coupled to hemofiltration to control hypercapnic acidosis in a porcine model of protective mechanical ventilation

    PubMed Central

    Tapia, Pablo; Lillo, Felipe; Soto, Dagoberto; Escobar, Leslie; Simon, Felipe; Hernández, Karina; Alegría, Leyla; Bruhn, Alejandro

    2016-01-01

    A promising approach to facilitate protective mechanical ventilation is the use of extracorporeal CO2 removal techniques. Several strategies based on membrane gas exchangers have been developed. However, these techniques are still poorly available. The goal of this study was to assess the efficacy and safety of THAM infusion coupled to hemofiltration for the management of hypercapnic acidosis. A severe respiratory acidosis was induced in seven anesthetized pigs. Five of them were treated with THAM 8-mmol·kg-1·h-1 coupled to hemofiltration (THAM+HF group) at 100 mL·kg-1·h-1. After 18-hours of treatment the THAM infusion was stopped but hemofiltration was kept on until 24-hours. The 2 other animals were treated with THAM but without hemofiltration. After 1-hour of treatment in THAM+HF, PaCO2 rapidly decreased from a median of 89.0 (IQR) (80.0, 98.0) to 71.3 (65.8, 82.0) mmHg (P<0.05), while pH increased from 7.12 (7.01, 7.15) to 7.29 (7.27, 7.30) (P<0.05). Thereafter PaCO2 remained stable between 60-70 mmHg, while pH increased above 7.4. After stopping THAM at 18 hours of treatment a profound rebound effect was observed with severe hypercapnic acidosis. The most important side effect we observed was hyperosmolality, which reached a maximum of 330 (328, 332) mOsm·kg H2O-1 at T18. The animals treated only with THAM developed severe hypercapnia, despite the fact that pH returned to normal values, and died after 12 hours. Control-group had an uneven evolution until the end of the experiment. A combined treatment with THAM coupled to hemofiltration may be an effective treatment to control severe hypercapnic acidosis. PMID:27648139

  5. Ventilatory muscle loads and the frequency-tidal volume pattern during inspiratory pressure-assisted (pressure-supported) ventilation.

    PubMed

    MacIntyre, N R; Leatherman, N E

    1990-02-01

    Pressure support ventilation (PSV) is a new form of mechanical ventilatory support that assists a patient's spontaneous ventilatory effort with a clinician-selected amount of inspiratory pressure. In order to assess the muscle unloading effect and the ventilatory pattern response to increasing levels of this inspiratory pressure assist, we first utilized a computer respiratory system model with variable alveolar ventilation demands and impedances. From this model, we calculated ventilatory muscle loads (expressed either as the work/min or as the pressure time index) during simulated, unassisted breathing and during simulated breathing with levels of inspiratory pressure assist up to that which resulted in a VT of 800 ml and no work being performed by the muscles (defined as PSVmax for the model conditions being studied). The optimal ventilatory pattern (i.e., frequency-tidal volume) under each ventilation and impedance condition was defined as that which resulted in minimal muscle load. Under these model conditions, we found that PSVmax ranged from 5 to 41 cm H2O and that as the level of inspiratory pressure assist was increased from zero to PSVmax, there was a biphasic response of both the ventilatory muscle loading and the ventilatory pattern. Specifically, at low levels of inspiratory pressure assist, the model predicted that the applied pressure would only partially unload the ventilatory muscles. Continued muscle energy expenditure would thus still be required, whereas the ventilatory pattern would change little. Conversely, at higher levels of inspiratory pressure assist, the model predicted that the applied pressure would be sufficient to completely unload the ventilatory muscles.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Respiratory muscle endurance is limited by lower ventilatory efficiency in post-myocardial infarction patients

    PubMed Central

    Neves, Laura M. T.; Karsten, Marlus; Neves, Victor R.; Beltrame, Thomas; Borghi-Silva, Audrey; Catai, Aparecida M.

    2014-01-01

    Background Reduced respiratory muscle endurance (RME) contributes to increased dyspnea upon exertion in patients with cardiovascular disease. Objective The objective was to characterize ventilatory and metabolic responses during RME tests in post-myocardial infarction patients without respiratory muscle weakness. Method Twenty-nine subjects were allocated into three groups: recent myocardial infarction group (RG, n=9), less-recent myocardial infarction group (LRG, n=10), and control group (CG, n=10). They underwent two RME tests (incremental and constant pressure) with ventilatory and metabolic analyses. One-way ANOVA and repeated measures one-way ANOVA, both with Tukey post-hoc, were used between groups and within subjects, respectively. Results Patients from the RG and LRG presented lower metabolic equivalent and ventilatory efficiency than the CG on the second (50± 06, 50± 5 vs. 42± 4) and third part (50± 11, 51± 10 vs. 43± 3) of the constant pressure RME test and lower metabolic equivalent during the incremental pressure RME test. Additionally, at the peak of the incremental RME test, RG patients had lower oxygen uptake than the CG. Conclusions Post-myocardial infarction patients present lower ventilatory efficiency during respiratory muscle endurance tests, which appears to explain their inferior performance in these tests even in the presence of lower pressure overload and lower metabolic equivalent. PMID:24675907

  7. Brainstem amino acid neurotransmitters and ventilatory response to hypoxia in piglets.

    PubMed

    Hehre, Dorothy A; Devia, Carlos J; Bancalari, Eduardo; Suguihara, Cleide

    2008-01-01

    The ventilatory response to hypoxia is influenced by the balance between inhibitory (GABA, glycine, and taurine) and excitatory (glutamate and aspartate) brainstem amino acid (AA) neurotransmitters. To assess the effects of AA in the nucleus tractus solitarius (NTS) on the ventilatory response to hypoxia at 1 and 2 wk of age, inhibitory and excitatory AA were sampled by microdialysis in unanesthetized and chronically instrumented piglets. Microdialysis samples from the NTS area were collected at 5-min intervals and minute ventilation (VE), arterial blood pressure (ABP), and arterial blood gases (ABG) were measured while the animals were in quiet sleep. A biphasic ventilatory response to hypoxia was observed in wk 1 and 2, but the decrease in VE at 10 and 15 min was more marked in wk 1. This was associated with an increase in inhibitory AA during hypoxia in wk 1. Excitatory AA levels were elevated during hypoxia in wk 1 and 2. Changes in ABP, pH, and ABG during hypoxia were not different between weeks. These data suggest that the larger depression in the ventilatory response to hypoxia observed in younger piglets is mediated by predominance of the inhibitory AA neurotransmitters, GABA, glycine, and taurine, in the NTS. PMID:18043517

  8. Mechanical load on the ventilatory muscles during an incremental cycle ergometer test.

    PubMed

    Wanke, T; Formanek, D; Schenz, G; Popp, W; Gatol, H; Zwick, H

    1991-04-01

    An incremental cycle ergometer test performed with a total of 40 healthy subjects (25 male, 15 female) was used to study the mechanical load on the ventilatory muscles. The parameters for the mechanical load on the ventilatory muscles are the time integral of the oesophageal pressure and the mean oesophageal pressure change per time unit (dPoe/dTI) of each breathing manoeuvre. The pressure-time integral is the area delimited by the oesophageal pressure trace and the inspiratory time axis. It is expressed as a fraction of the product of the subject's maximum oesophageal pressure (Poe(max)) and total breath cycle duration (TTOT). This parameter is called oesophageal tension time index (TTIoe). The relationship between minute ventilation and these two parameters during ergometer test showed gender-specific variations because of the differences between men and women as to anthropometric data, lung function parameters and maximum ventilatory muscle strength. Moreover, the dPoe/dTI values significantly depend on the breathing frequency. The present study has provided evidence that, in general, the TTIoe and dPoe/dTI values in terms of a specific minute ventilation (VE) are higher in women than in men. Parameters for the mechanical load on the ventilatory muscles regarding the level of pressure to be generated as well as the duration and velocity of muscle contraction should therefore also allow for the gender of the patients.

  9. Morphine has latent deleterious effects on the ventilatory responses to a hypoxic challenge.

    PubMed

    May, Walter J; Gruber, Ryan B; Discala, Joseph F; Puskovic, Veljko; Henderson, Fraser; Palmer, Lisa A; Lewis, Stephen J

    2013-11-01

    The aim of this study was to determine whether morphine depresses the ventilatory responses elicited by a hypoxic challenge (10% O2, 90% N2) in conscious rats at a time when the effects of morphine on arterial blood gas (ABG) chemistry, Alveolar-arterial (A-a) gradient and minute ventilation (VM) had completely subsided. In vehicle-treated rats, each episode of hypoxia stimulated ventilatory function and the responses generally subsided during each normoxic period. Morphine (5 mg/kg, i.v.) induced an array of depressant effects on ABG chemistry, A-a gradient and VM (via decreases in tidal volume). Despite resolution of these morphine-induced effects, the first episode of hypoxia elicited substantially smaller increases in VM than in vehicle-treated rats, due mainly to smaller increases in frequency of breathing. The pattern of ventilatory responses during subsequent episodes of hypoxia and normoxia changed substantially in morphine-treated rats. It is evident that morphine has latent deleterious effects on ventilatory responses elicited by hypoxic challenge. PMID:25045593

  10. Il-1β and prostaglandin E2 attenuate the hypercapnic as well as the hypoxic respiratory response via prostaglandin E receptor type 3 in neonatal mice.

    PubMed

    Siljehav, Veronica; Shvarev, Yuri; Herlenius, Eric

    2014-11-01

    Prostaglandin E2 (PGE2) serves as a critical mediator of hypoxia, infection, and apnea in term and preterm babies. We hypothesized that the prostaglandin E receptor type 3 (EP3R) is the receptor responsible for PGE2-induced apneas. Plethysmographic recordings revealed that IL-1β (ip) attenuated the hypercapnic response in C57BL/6J wild-type (WT) but not in neonatal (P9) EP3R(-/-) mice (P < 0.05). The hypercapnic responses in brain stem spinal cord en bloc preparations also differed depending on EP3R expression whereby the response was attenuated in EP3R(-/-) preparations (P < 0.05). After severe hypoxic exposure in vivo, IL-1β prolonged time to autoresuscitation in WT but not in EP3R(-/-) mice. Moreover, during severe hypoxic stress EP3R(-/-) mice had an increased gasping duration (P < 0.01) as well as number of gasps (P < 0.01), irrespective of intraperitoneal treatment, compared with WT mice. Furthermore, EP3R(-/-) mice exhibited longer hyperpneic breathing efforts when exposed to severe hypoxia (P < 0.01). This was then followed by a longer period of secondary apnea before autoresuscitation occurred in EP3R(-/-) mice (P < 0.05). In vitro, EP3R(-/-) brain stem spinal cord preparations had a prolonged respiratory burst activity during severe hypoxia accompanied by a prolonged neuronal arrest during recovery in oxygenated medium (P < 0.05). In conclusion, PGE2 exerts its effects on respiration via EP3R activation that attenuates the respiratory response to hypercapnia as well as severe hypoxia. Modulation of the EP3R may serve as a potential therapeutic target for treatment of inflammatory and hypoxic-induced detrimental apneas and respiratory disorders in neonates.

  11. Ventilatory inhomogeneity determined from multiple-breath washouts during sustained microgravity on Spacelab SLS-1

    NASA Technical Reports Server (NTRS)

    Prisk, G. Kim; Guy, Harold J. B.; Elliott, Ann R.; Paiva, Manuel; West, John B.

    1995-01-01

    We used multiple-breath N2 washouts (MBNW) to study the homogeneity of ventilation in four normal humans (mean age 42.5 yr) before, during, and after 9 days of exposure to microgravity on Spacelab Life Sciences-1. Subjects performed 20-breath MBNW at tidal volumes of approximately 700 ml and 12-breath MBNW at tidal volumes of approximately 1,250 ml. Six indexes of ventilatory inhomogeneity were derived from data from (1) distribution of specific ventilation (SV) from mixed-expired and (2) end-tidal N2, (3) change of slope of N2 washout (semilog plot) with time, (4) change of slope of normalized phase III of successive breaths, (5) anatomic lead dead space, and (6) Bohr dead space. Significant ventilatory inhomogeneity was seen in the standing position at normal gravity (1 G). When we compared standing 1 G with microgravity, the distributions of SV became slightly narrower, but the difference was not significant. Also, there were no significant changes in the change of slope of the N2 washout, change of normalized phase III slopes, or the anatomic and Bohr dead spaces. By contrast, transition from the standing to supine position in 1 G resulted in significantly broader distributions of SV and significantly greater changes in the changes in slope of the N2 washouts, indicating more ventilatory inhomogeneity in that posture. Thus these techniques can detect relatively small changes in ventilatory inhomogeneity. We conclude that the primary determinants of ventilatory inhomogeneity during tidal breathing in the upright posture are not gravitational in origin.

  12. Central ventilatory and cardiovascular actions of trout gastrin-releasing peptide (GRP) in the unanesthetized trout

    PubMed Central

    Le Mével, Jean-Claude; Lancien, Frédéric; Mimassi, Nagi; Kermorgant, Marc; Conlon, J. Michael

    2013-01-01

    Summary Gastrin-releasing peptide (GRP), a neuropeptide initially isolated from porcine stomach, shares sequence similarity with bombesin. GRP and its receptors are present in the brains and peripheral tissues of several species of teleost fish, but little is known about the ventilatory and cardiovascular effects of this peptide in these vertebrates. The goal of this study was to compare the central and peripheral actions of picomolar doses of trout GRP on ventilatory and cardiovascular variables in the unanesthetized rainbow trout. Compared to vehicle, intracerebroventricular (ICV) injection of GRP (1–50 pmol) significantly elevated the ventilation rate (ƒV) and the ventilation amplitude (VAMP), and consequently the total ventilation (VTOT). The maximum hyperventilatory effect of GRP (VTOT: +225%), observed at a dose of 50 pmol, was mostly due to its stimulatory action on VAMP (+170%) rather than ƒV (+20%). In addition, ICV GRP (50 pmol) produced a significant increase in mean dorsal aortic blood pressure (PDA) (+35%) and in heart rate (ƒH) (+25%). Intra-arterial injections of GRP (5–100 pmol) were without sustained effect on the ventilatory variables but produced sporadic and transient increases in ventilatory movement at doses of 50 and 100 pmol. At these doses, GRP elevated PDA by +20% but only the 50 pmol dose significantly increased HR (+15%). In conclusion, our study suggests that endogenous GRP within the brain of the trout may act as a potent neurotransmitter and/or neuromodulator in the regulation of cardio-ventilatory functions. In the periphery, endogenous GRP may act as locally-acting and/or circulating neurohormone with an involvement in vasoregulatory mechanisms. PMID:24143283

  13. Pulmonary function in firefighters: acute changes in ventilatory capacity and their correlates.

    PubMed Central

    Musk, A W; Smith, T J; Peters, J M; McLaughlin, E

    1979-01-01

    A group of 39 firefighters was examined during routine firefighing duty. Following smoke exposure the average decrease in one-second forced expiratory volume (FEV1.0) was 0.05 litre (137 observations). This decline in FEV1.0 was related to the severity of smoke exposure as estimated by the firefighter and to the measured particulate concentration of the smoke to which he was exposed. Decreases in FEV1.0 in excess of 0.10 litre were recorded in 30% of observations. Changes in FEV1.0 resulting from a second exposure to smoke on the same tour of duty were greater when smoke exposure at the previous fire was heavy. The repeated episodes of irritation of the bronchial tree that have been documented in this investigation may explain the origin of the previously observed chronic effect of firefighting on respiratory symptoms and pulmonary function. PMID:444439

  14. Transition from acute to chronic hypercapnia in patients with periodic breathing: predictions from a computer model.

    PubMed

    Norman, Robert G; Goldring, Roberta M; Clain, Jeremy M; Oppenheimer, Beno W; Charney, Alan N; Rapoport, David M; Berger, Kenneth I

    2006-05-01

    Acute hypercapnia may develop during periodic breathing from an imbalance between abnormal ventilatory patterns during apnea and/or hypopnea and compensatory ventilatory response in the interevent periods. However, transition of this acute hypercapnia into chronic sustained hypercapnia during wakefulness remains unexplained. We hypothesized that respiratory-renal interactions would play a critical role in this transition. Because this transition cannot be readily addressed clinically, we modified a previously published model of whole-body CO2 kinetics by adding respiratory control and renal bicarbonate kinetics. We enforced a pattern of 8 h of periodic breathing (sleep) and 16 h of regular ventilation (wakefulness) repeated for 20 days. Interventions included varying the initial awake respiratory CO2 response and varying the rate of renal bicarbonate excretion within the physiological range. The results showed that acute hypercapnia during periodic breathing could transition into chronic sustained hypercapnia during wakefulness. Although acute hypercapnia could be attributed to periodic breathing alone, transition from acute to chronic hypercapnia required either slowing of renal bicarbonate kinetics, reduction of ventilatory CO2 responsiveness, or both. Thus the model showed that the interaction between the time constant for bicarbonate excretion and respiratory control results in both failure of bicarbonate concentration to fully normalize before the next period of sleep and persistence of hypercapnia through blunting of ventilatory drive. These respiratory-renal interactions create a cumulative effect over subsequent periods of sleep that eventually results in a self-perpetuating state of chronic hypercapnia.

  15. Transition from acute to chronic hypercapnia in patients with periodic breathing: predictions from a computer model.

    PubMed

    Norman, Robert G; Goldring, Roberta M; Clain, Jeremy M; Oppenheimer, Beno W; Charney, Alan N; Rapoport, David M; Berger, Kenneth I

    2006-05-01

    Acute hypercapnia may develop during periodic breathing from an imbalance between abnormal ventilatory patterns during apnea and/or hypopnea and compensatory ventilatory response in the interevent periods. However, transition of this acute hypercapnia into chronic sustained hypercapnia during wakefulness remains unexplained. We hypothesized that respiratory-renal interactions would play a critical role in this transition. Because this transition cannot be readily addressed clinically, we modified a previously published model of whole-body CO2 kinetics by adding respiratory control and renal bicarbonate kinetics. We enforced a pattern of 8 h of periodic breathing (sleep) and 16 h of regular ventilation (wakefulness) repeated for 20 days. Interventions included varying the initial awake respiratory CO2 response and varying the rate of renal bicarbonate excretion within the physiological range. The results showed that acute hypercapnia during periodic breathing could transition into chronic sustained hypercapnia during wakefulness. Although acute hypercapnia could be attributed to periodic breathing alone, transition from acute to chronic hypercapnia required either slowing of renal bicarbonate kinetics, reduction of ventilatory CO2 responsiveness, or both. Thus the model showed that the interaction between the time constant for bicarbonate excretion and respiratory control results in both failure of bicarbonate concentration to fully normalize before the next period of sleep and persistence of hypercapnia through blunting of ventilatory drive. These respiratory-renal interactions create a cumulative effect over subsequent periods of sleep that eventually results in a self-perpetuating state of chronic hypercapnia. PMID:16384839

  16. Long-term modulation of the exercise ventilatory response in goats.

    PubMed Central

    Martin, P A; Mitchell, G S

    1993-01-01

    1. To test the hypothesis that repeated associations of exercise and increased respiratory dead space elicit mechanisms that augment future ventilatory responses to exercise alone, experiments were conducted on normal adult goats familiarized with experimental procedures. 2. Measurements of ventilation, arterial blood gases and CO2 production were made at rest, during mild steady-state exercise (4 km h-1; 5% grade) and with increased dead space at rest in seven goats before and after training. In Series I experiments, training consisted of fourteen to twenty exercise trials explicitly paired with increased dead space (0.8 l) over 2 days. Increased dead space predominantly represents a CO2 chemoreceptor stimulus with only mild hypoxic stimulation. Post-training measurements were made 1-6 h and 1 week after training was completed. 3. The same goats repeated a slightly modified protocol several months later (Series II; 6 trials per day for 4 days) to determine if responses were both repeatable and reversible, and to investigate training effects on dynamic ventilatory responses at the onset of exercise. 4. In Series I experiments, resting minute ventilation and breathing frequency were elevated 1-6 h post-training compared to baseline (44 and 74% respectively), whereas resting tidal volume decreased (14%). One week post-training, resting values had returned to baseline. Series II training had no significant effects on resting measurements. 5. Relative to baseline, arterial partial pressure of CO2 (Pa,CO2) values decreased significantly more from rest to exercise 1-6 h post-training in both Series I (2.7 +/- 0.2 vs. 1.8 +/- 0.9 mmHg) and Series II (3.4 +/- 0.6 vs. 2.0 +/- 0.6 mmHg). The exercise ventilatory response increased 25-28% 1-6 h post-training (both series), largely due to a greater exercise frequency response, but returned to baseline 1 week post-training. Training had no effect on ventilatory responses to CO2 at rest, suggesting that decreases in CO2

  17. Acute bronchial asthma.

    PubMed

    Grover, Sudhanshu; Jindal, Atul; Bansal, Arun; Singhi, Sunit C

    2011-11-01

    Acute asthma is the third commonest cause of pediatric emergency visits at PGIMER. Typically, it presents with acute onset respiratory distress and wheeze in a patient with past or family history of similar episodes. The severity of the acute episode of asthma is judged clinically and categorized as mild, moderate and severe. The initial therapy consists of oxygen, inhaled beta-2 agonists (salbutamol or terbutaline), inhaled budesonide (three doses over 1 h, at 20 min interval) in all and ipratropium bromide and systemic steroids (hydrocortisone or methylprednisolone) in acute severe asthma. Other causes of acute onset wheeze and breathing difficulty such as pneumonia, foreign body, cardiac failure etc. should be ruled out with help of chest radiography and appropriate laboratory investigations in first time wheezers and those not responding to 1 h of inhaled therapy. In case of inadequate response or worsening, intravenous infusion of magnesium sulphate, terbutaline or aminophylline may be used. Magnesium sulphate is the safest and most effective alternative among these. Severe cases may need ICU care and rarely, ventilatory support. PMID:21769523

  18. [Immunologic reactions, respiratory symptoms and ventilatory capacity in jute and sisal textile workers].

    PubMed

    Zuskin, E; Kanceljak, B; Mustajbegović, J; Kern, J

    1993-03-01

    Allergic reactions in relation to respiratory symptoms and ventilatory capacity were studied in 41 textile workers employed in the processing of jute and sisal. Only 5.0% of the jute workers and 9.5% of the sisal workers demonstrated positive skin reactions to jute or sisal allergens. Increased IgE was found in 9.8% of the textile workers. Among 35 control workers 11.4% reacted with a positive skin reaction to the jute or sisal allergen and 2.9% had increased IgE. Chronic respiratory symptoms as well as changes in ventilatory capacity were found in textile workers with positive and negative skin tests. Our data suggest that immunological reactions are not likely to be responsible for the development of respiratory impairment in textile workers exposed to jute and sisal dust.

  19. Ventilatory and metabolic responses of burrowing owls, Athene cunicularia, to moderate and extreme hypoxia: analysis of the hypoxic ventilatory threshold vs. hemoglobin oxygen affinity relationship in birds.

    PubMed

    Kilgore, Delbert L; Boggs, Dona F; Kilgore, Trevor J; Colby, Conrad; Williams, Burl R; Bavis, Ryan W

    2008-06-01

    We measured ventilation, oxygen consumption and blood gases in burrowing owls (Athene cunicularia) breathing moderate and extreme hypoxic gas mixtures to determine their hypoxic ventilatory threshold (HVT) and to assess if they, like other birds and mammals, exhibit a relationship between HVT and hemoglobin O2 affinity (P(50)) of their blood. An earlier report of an attenuated ventilatory responsiveness of this species to hypoxia was enigmatic given the low O2 affinity (high P(50)) of burrowing owl hemoglobin. In the current study, burrowing owls breathing 11% and 9% O2 showed a significantly elevated total ventilation. The arterial partial pressure of oxygen (PaO2) at which ventilation is elevated above normoxic values in burrowing owls was 58 mm Hg. This threshold value conforms well to expectations based on the high P(50) of their hemoglobin and the HVT vs. P(50) relationship for birds developed in this study. Correcting for phylogenetic relatedness in the multi-species analysis had no effect on the HVT vs. P(50) relationship. Also, because burrowing owls in this study did not show a hypometabolic response at any level of hypoxia (even at 9% O2); HVT described in terms of percent change in oxygen convection requirement is identical to that based on ventilation alone. PMID:17561426

  20. Ventilatory and metabolic responses of burrowing owls, Athene cunicularia, to moderate and extreme hypoxia: analysis of the hypoxic ventilatory threshold vs. hemoglobin oxygen affinity relationship in birds.

    PubMed

    Kilgore, Delbert L; Boggs, Dona F; Kilgore, Trevor J; Colby, Conrad; Williams, Burl R; Bavis, Ryan W

    2008-06-01

    We measured ventilation, oxygen consumption and blood gases in burrowing owls (Athene cunicularia) breathing moderate and extreme hypoxic gas mixtures to determine their hypoxic ventilatory threshold (HVT) and to assess if they, like other birds and mammals, exhibit a relationship between HVT and hemoglobin O2 affinity (P(50)) of their blood. An earlier report of an attenuated ventilatory responsiveness of this species to hypoxia was enigmatic given the low O2 affinity (high P(50)) of burrowing owl hemoglobin. In the current study, burrowing owls breathing 11% and 9% O2 showed a significantly elevated total ventilation. The arterial partial pressure of oxygen (PaO2) at which ventilation is elevated above normoxic values in burrowing owls was 58 mm Hg. This threshold value conforms well to expectations based on the high P(50) of their hemoglobin and the HVT vs. P(50) relationship for birds developed in this study. Correcting for phylogenetic relatedness in the multi-species analysis had no effect on the HVT vs. P(50) relationship. Also, because burrowing owls in this study did not show a hypometabolic response at any level of hypoxia (even at 9% O2); HVT described in terms of percent change in oxygen convection requirement is identical to that based on ventilation alone.

  1. Ventilatory effects of low-dose paraoxon result from central muscarinic effects

    SciTech Connect

    Houze, Pascal; Pronzola, Laetita; Kayouka, Maya; Villa, Antoine; Debray, Marcel; Baud, Frederic J.

    2008-12-01

    Paraoxon induces respiratory toxicity. Atropine completely reversed parathion- and paraoxon-induced respiratory toxicity. The aim of this study was to assess the peripheral or central origin of ventilatory effects of low-dose paraoxon. Male Sprague-Dawley rats were given paraoxon 0.215 mg/kg subcutaneously and treated with either atropine (10 mg/kg sc) or ascending doses of methylatropine of 5.42 (equimolar to that of atropine), 54.2, and 542 mg/kg administered subcutaneously 30 min after paraoxon. Ventilation at rest was assessed using whole-body plethysmography and rat temperature using infra-red telemetry. Results are expressed as mean {+-} SE. Statistical analysis used two-way ANOVA for repeated measurements. Paraoxon induced a significant decrease in temperature 30 min after injection lasting the 90 min of the study period. This effect was partially corrected by atropine, but not by methylatropine whatever the dose. Paraoxon induced a decrease in respiratory rate resulting from an increase in expiratory time associated with an increase in tidal volume. Atropine completely reversed the ventilatory effects of low-dose paraoxon while the equimolar dose of methylatropine had no significant effects. The 54.2 and 542 mg/kg doses of methylatropine had no significant effects. Atropine crosses the blood-brain barrier and reverses peripheral and central muscarinic effects. In contrast, methylatropine does not cross the blood-brain barrier. Atropine completely reversed the ventilatory effects of low-dose paraoxon, while methylatropine had no significant effects at doses up to 100-fold the equimolar dose of atropine. We conclude that the ventilatory effects of low-dose paraoxon are mediated by disrupted muscarinic signaling in the central nervous system.

  2. Ventilatory compensation of the alkaline tide during digestion in the snake Boa constrictor.

    PubMed

    Andrade, Denis V; De Toledo, Luis Felipe; Abe, Augusto S; Wang, Tobias

    2004-03-01

    The increased metabolic rate during digestion is associated with changes in arterial acid-base parameters that are caused by gastric acid secretion (the 'alkaline tide'). Net transfer of HCl to the stomach lumen causes an increase in plasma HCO3- levels, but arterial pH does not change because of a ventilatory compensation that counters the metabolic alkalosis. It seems, therefore, that ventilation is controlled to preserve pH and not PCO2 during the postprandial period. To investigate this possibility, we determined arterial acid-base parameters and the metabolic response to digestion in the snake Boa constrictor, where gastric acid secretion was inhibited pharmacologically by oral administration of omeprazole. The increase in oxygen consumption of omeprazole-treated snakes after ingestion of 30% of their own body mass was quantitatively similar to the response in untreated snakes, although the peak of the metabolic response occurred later (36 h versus 24 h). Untreated control animals exhibited a large increase in arterial plasma HCO3- concentration of approximately 12 mmol l(-1), but arterial pH only increased by 0.12 pH units because of a simultaneous increase in arterial PCO2 by about 10 mmHg. Omeprazole virtually abolished the changes in arterial pH and plasma HCO3- concentration during digestion and there was no increase in arterial PCO2. The increased arterial PCO2 during digestion is not caused, therefore, by the increased metabolism during digestion or a lower ventilatory responsiveness to ventilatory stimuli during a presumably relaxed state in digestion. Furthermore, the constant arterial PCO2, in the absence of an alkaline tide, of omeprazole-treated snakes strongly suggests that pH rather than PCO2 normally affects chemoreceptor activity and ventilatory drive.

  3. Ventilatory efficiency and breathing pattern in world-class cyclists: A three-year observational study.

    PubMed

    Salazar-Martínez, Eduardo; Terrados, Nicolás; Burtscher, Martin; Santalla, Alfredo; Naranjo Orellana, José

    2016-07-15

    The purpose of this three-year observational study was to analyze the ventilatory efficiency and breathing pattern in world-class professional cyclists. Twelve athletes (22.61±3.8years; 177.38±5.5cm; 68.96±5.5kg and VO2max 75.51±3.3mLkg(-1)min(-1)) were analyzed retrospectively. For each subject, respiratory and performance variables were recorded during incremental spiroergometry: oxygen uptake (VO2), carbon dioxide output (VCO2), pulmonary ventilation (VE), tidal volume (Vt), breathing frequency (fR), driving (Vt/Ti), timing (Ti/Ttot), peak power output (PPO) and maximum oxygen uptake (VO2max). Ventilatory efficiency (VE/VCO2 slope) was calculated from the beginning of exercise testing to the second ventilatory threshold (VT2). The VE/VCO2 slope was unaffected during the study period (24.63±3.07; 23.61±2:79; 24:89±2:61) with a low effect size (ES=0.04). The PPO improved significantly in the third year (365±33.74; 386.36±32.33; 415.00±24.15) (p<0.05). The breathing pattern variables, Vt/Ti and Ti/Ttot, did not change significantly over the three year period (ES=0.00; ES=0.03 respectively). These findings suggest that changes in cycling performance in world-class professional cyclists do not modify breathing variables related to the control of ventilatory efficiency.

  4. Ventilatory efficiency and breathing pattern in world-class cyclists: A three-year observational study.

    PubMed

    Salazar-Martínez, Eduardo; Terrados, Nicolás; Burtscher, Martin; Santalla, Alfredo; Naranjo Orellana, José

    2016-07-15

    The purpose of this three-year observational study was to analyze the ventilatory efficiency and breathing pattern in world-class professional cyclists. Twelve athletes (22.61±3.8years; 177.38±5.5cm; 68.96±5.5kg and VO2max 75.51±3.3mLkg(-1)min(-1)) were analyzed retrospectively. For each subject, respiratory and performance variables were recorded during incremental spiroergometry: oxygen uptake (VO2), carbon dioxide output (VCO2), pulmonary ventilation (VE), tidal volume (Vt), breathing frequency (fR), driving (Vt/Ti), timing (Ti/Ttot), peak power output (PPO) and maximum oxygen uptake (VO2max). Ventilatory efficiency (VE/VCO2 slope) was calculated from the beginning of exercise testing to the second ventilatory threshold (VT2). The VE/VCO2 slope was unaffected during the study period (24.63±3.07; 23.61±2:79; 24:89±2:61) with a low effect size (ES=0.04). The PPO improved significantly in the third year (365±33.74; 386.36±32.33; 415.00±24.15) (p<0.05). The breathing pattern variables, Vt/Ti and Ti/Ttot, did not change significantly over the three year period (ES=0.00; ES=0.03 respectively). These findings suggest that changes in cycling performance in world-class professional cyclists do not modify breathing variables related to the control of ventilatory efficiency. PMID:27083403

  5. Periodic breathing at high altitude and ventilatory responses to O2 and CO2.

    PubMed

    Masuyama, S; Kohchiyama, S; Shinozaki, T; Okita, S; Kunitomo, F; Tojima, H; Kimura, H; Kuriyama, T; Honda, Y

    1989-01-01

    To determine the relationship between periodic breathing (PB) during sleep at high altitude and ventilatory chemosensitivities, we studied nine Japanese climbers who participated in the expedition to the Kunlun Mountains (7,167 m) in China in 1986. At sea level, ventilatory response to hypoxia (HVR) by isocapnic progressive hypoxia test and to hypercapnia (HCVR) by Read's method were examined. At altitude 5,360 m, respiratory movements of the chest and abdominal wall, SaO2, ECG, and HR were monitored. Seven climbers manifested PB during sleep. There was a significant correlation between PB during sleep and HVR and HCVR (p less than 0.05). All the climbers showed severe desaturation during sleep. There was a significant negative correlation between degree of desaturation during sleep and HVR (p less than 0.05). A negative correlation was also detected between PB and the degree of desaturation during sleep. We concluded that ventilatory chemosensitivities play an important role in eliciting PB and that climbers with high HVR can maintain their arterial oxygenation during sleep, due to hyperventilation induced by PB, which is considered an advantageous adaptation for lowland sojourners.

  6. Modified ventilatory response characteristics to exercise in breath-hold divers.

    PubMed

    Roecker, Kai; Metzger, Jule; Scholz, Tobias; Tetzlaff, Kay; Sorichter, Stephan; Walterspacher, Stephan

    2014-09-01

    Specific adjustments to repeated extreme apnea are not fully known and understood. While a blunted ventilatory chemosensitivity to CO2 is described for elite breath-hold divers (BHDs) at rest, it is unclear whether specific adaptations affect their response to dynamic exercise. Eight elite BHDs with a previously validated decrease in CO2 chemosensitivity, 8 scuba divers (SCDs), and 8 matched control subjects were included in a study where markers of ventilatory response, Fowler's dead space, partial pressure of carbon dioxide (pCO2), and blood lactate concentrations during cycle exercise were measured. Maximal power output did not differ between the groups, but lactate threshold (θL) appeared at a significantly lowered respiratory compensation point (RCP) and at a higher VO2 for the BHDs. End-tidal (petCO2) and estimated arterial pCO2 (paCO2) were significantly higher in BHDs at θL, the RCP, and maximum exhaustion. BHDs showed a significantly (P < .01) slower breathing pattern in relation to a given tidal volume at a specific work rate. In summary, BHDs presented signs of a metabolic shift from aerobic to anaerobic energy supply, decreased chemosensitivity during exercise, and a distinct ventilatory-response pattern during cycle exercise that differs from SCDs and controls. PMID:24231513

  7. Management of Ventilatory Insufficiency in Neuromuscular Patients Using Mechanical Ventilator Supported by the Korean Government.

    PubMed

    Kang, Seong-Woong; Choi, Won Ah; Cho, Han Eol; Lee, Jang Woo; Park, Jung Hyun

    2016-06-01

    Since 2001, financial support has been provided for all patients with neuromuscular disease (NMD) who require ventilatory support due to the paralysis of respiratory muscles in Korea. The purpose of this study was to identify ventilator usage status and appropriateness in these patients. We included 992 subjects with rare and incurable NMD registered for ventilator rental fee support. From 21 February 2011 to 17 January 2013, ventilator usage information, regular follow-up observation, and symptoms of chronic hypoventilation were surveyed by phone. Home visits were conducted for patients judged by an expert medical team to require medical examination. Abnormal ventilatory status was assessed by respiratory evaluation. Chronic respiratory insufficiency symptoms were reported by 169 of 992 subjects (17%), while 565 subjects (57%) did not receive regular respiratory evaluation. Ventilatory status was abnormal in 102 of 343 home-visit subjects (29.7%). Although 556 subjects (56%) reported 24-hour ventilator use, only 458 (46%) had an oxygen saturation monitoring device, and 305 (31%) performed an airstacking exercise. A management system that integrates ventilator usage monitoring, counselling and advice, and home visits for patients who receive ventilator support could improve the efficiency of the ventilator support project.

  8. Modified ventilatory response characteristics to exercise in breath-hold divers.

    PubMed

    Roecker, Kai; Metzger, Jule; Scholz, Tobias; Tetzlaff, Kay; Sorichter, Stephan; Walterspacher, Stephan

    2014-09-01

    Specific adjustments to repeated extreme apnea are not fully known and understood. While a blunted ventilatory chemosensitivity to CO2 is described for elite breath-hold divers (BHDs) at rest, it is unclear whether specific adaptations affect their response to dynamic exercise. Eight elite BHDs with a previously validated decrease in CO2 chemosensitivity, 8 scuba divers (SCDs), and 8 matched control subjects were included in a study where markers of ventilatory response, Fowler's dead space, partial pressure of carbon dioxide (pCO2), and blood lactate concentrations during cycle exercise were measured. Maximal power output did not differ between the groups, but lactate threshold (θL) appeared at a significantly lowered respiratory compensation point (RCP) and at a higher VO2 for the BHDs. End-tidal (petCO2) and estimated arterial pCO2 (paCO2) were significantly higher in BHDs at θL, the RCP, and maximum exhaustion. BHDs showed a significantly (P < .01) slower breathing pattern in relation to a given tidal volume at a specific work rate. In summary, BHDs presented signs of a metabolic shift from aerobic to anaerobic energy supply, decreased chemosensitivity during exercise, and a distinct ventilatory-response pattern during cycle exercise that differs from SCDs and controls.

  9. Management of Ventilatory Insufficiency in Neuromuscular Patients Using Mechanical Ventilator Supported by the Korean Government

    PubMed Central

    2016-01-01

    Since 2001, financial support has been provided for all patients with neuromuscular disease (NMD) who require ventilatory support due to the paralysis of respiratory muscles in Korea. The purpose of this study was to identify ventilator usage status and appropriateness in these patients. We included 992 subjects with rare and incurable NMD registered for ventilator rental fee support. From 21 February 2011 to 17 January 2013, ventilator usage information, regular follow-up observation, and symptoms of chronic hypoventilation were surveyed by phone. Home visits were conducted for patients judged by an expert medical team to require medical examination. Abnormal ventilatory status was assessed by respiratory evaluation. Chronic respiratory insufficiency symptoms were reported by 169 of 992 subjects (17%), while 565 subjects (57%) did not receive regular respiratory evaluation. Ventilatory status was abnormal in 102 of 343 home-visit subjects (29.7%). Although 556 subjects (56%) reported 24-hour ventilator use, only 458 (46%) had an oxygen saturation monitoring device, and 305 (31%) performed an airstacking exercise. A management system that integrates ventilator usage monitoring, counselling and advice, and home visits for patients who receive ventilator support could improve the efficiency of the ventilator support project. PMID:27247509

  10. Ventilatory thresholds during wheelchair exercise in individuals with spinal cord injuries.

    PubMed

    Coutts, K D; McKenzie, D C

    1995-07-01

    The ventilatory thresholds of 30 male wheelchair athletes were determined from their respiratory and metabolic responses to a continuously progressive exercise protocol to peak oxygen uptake on a wheelchair ergometer. The peak oxygen uptake (peak VO2), ventilatory threshold in 1 min-1 (VTL), and ventilatory threshold expressed as a percentage of peak VO2 (VT%) were measured for all subjects. Statistical analyses of selected subsamples were used to note sport and functional ability level differences in these variables. Analysis of peak VO2 by functional classification (old International Stoke Mandeville Games Federation system; classes 1A-5, plus an amputee class) indicated that paraplegic (classes 2-5) and the amputee class athletes (2.48 1 min-1) were higher than tetraplegic (classes 1A-1C) athletes (0.95 1 min-1). The paraplegic and amputee classes were combined for a comparison of peak VO2 by sport which showed that track athletes (2.80 1 min-1) were higher than basketball players (2.41 1 min-1) who were higher than athletes from other sports (1.88 1 min-1). The VTL analyses demonstrated differences similar to the peak VO2 analyses. The VT% analyses, however, showed no sport differences, but the tetraplegic athletes had higher VT% values (87%) than the paraplegic plus amputee group (69%).

  11. Is the voluntary control of exercise in man necessary for the ventilatory response?

    PubMed Central

    Adams, L; Garlick, J; Guz, A; Murphy, K; Semple, S J

    1984-01-01

    The ventilatory response to electrically induced exercise (EEL) was studied in eighteen normal subjects and compared with the response to performing the same exercise voluntarily (EV). EEL was produced by surface electrode stimulation of the quadriceps and hamstring muscles so as to cause a pushing movement at 1 HZ against a spring load; this produced no pain or discomfort. Matching of EV to EEL was achieved by subjects copying a tension signal recorded during EEL and displayed on a storage oscilloscope. There were no differences between the resting states measured before either form of exercise. The ventilatory response (change in ventilation as a ratio of the change in CO2 elimination) was similar in the two types of exercise. The increases in ventilation and CO2 elimination were greater with EEL. Small but significant increases in the gas exchange ratio and serum lactate were found for EEL but not for EV, suggesting an increase in anaerobic metabolism in EEL. End-tidal PCO2 showed little change in either form of exercise. In some runs end-tidal PCO2 rose, but insufficiently to account for the ventilatory response as judged by the response to inhaled CO2. In two subjects arterial blood samples showed small and inconsistent changes in both Pa,CO2 and PaO2 for EV and EEL. pH and base excess changes also were consistent with more anaerobiosis with EEL compared to EV. The first ten breaths of exercise were used to study the on transient. In EV, expiratory duration shortened and ventilation increased significantly on the first breath but CO2 elimination did not increase until the second breath; in EEL, these variables did not change significantly until the second breath. For the remainder of the on transient the pattern of the ventilatory response was similar for EV and EEL. By the end of the on transient both EV and EEL had reached approximately 80% of their final steady-state values. These results suggest that a normal ventilatory response can occur in the absence

  12. Anesthesia for Endovascular Approaches to Acute Ischemic Stroke.

    PubMed

    Avitsian, Rafi; Machado, Sandra B

    2016-09-01

    Involvement of the Anesthesiologist in the early stages of care for acute ischemic stroke patient undergoing endovascular treatment is essential. Anesthetic management includes the anesthetic technique (general anesthesia vs sedation), a matter of much debate and an area in need of well-designed prospective studies. The large numbers of confounding factors make the design of such studies a difficult process. A universally agreed point in the endovascular management of acute ischemic stroke is the importance of decreasing the time to revascularization. Hemodynamic and ventilatory management and implementation of neuroprotective modalities and treatment of acute procedural complications are important components of the anesthetic plan. PMID:27521194

  13. Acute respiratory effects of exposure to diesel emissions in coal miners

    SciTech Connect

    Ames, R.G.; Attfield, M.D.; Hankinson, J.L.; Hearl, F.J.; Reger, R.B.

    1982-01-01

    A study was conducted to determine if acute respiratory effects, measured in terms of changes in forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and maximal expiratory flow rate at 50% of forced vital capacity (Vmax50), were related to exposure to diesel emissions in coal miners. Sixty coal miners exposed to diesel emissions and 90 miners not exposed were tested before and after a work shift for ventilatory function changes. Significant work shift decrements in ventilatory function did occur in miners in both groups who smoked cigarettes, but there were no significant differences in the ventilatory function changes between those miners exposed to diesel emissions and those not exposed either in the aggregate or under control by smoking status.

  14. The increased ventilatory response to exercise in chronic heart failure: relation to pulmonary pathology.

    PubMed Central

    Clark, A. L.; Volterrani, M.; Swan, J. W.; Coats, A. J.

    1997-01-01

    OBJECTIVE: To assess the exercise limitation of patients with chronic heart failure (CHF) and its relation to possible pulmonary and ventilatory abnormalities. SETTING: A tertiary referral centre for cardiology. METHODS: The metabolic gas exchange responses to maximum incremental treadmill exercise were assessed in 55 patients with CHF (mean (SD) age 57.9 (13.0) years; 5 female, 50 male) and 24 controls (age 53.0 (11.1) years; 4 female, 20 male). Ventilatory response was calculated as the slope of the relation between ventilation and carbon dioxide production (VE/VCO2 slope). RESULTS: Oxygen consumption (VO2) was the same at each stage in each group. Ventilation (VE) was higher in patients at each stage. Patients had a lower peak VO2 and a steeper VE/VCO2 slope than controls. Dead space ventilation as a fraction of tidal volume (VD/VT) was higher in patients at peak exercise, but dead space per breath was greater in controls at peak exercise (0.74 (0.29) v 0.57 (0.17) litres/breath; P = 0.002). End tidal CO2 was lower in patients at all stages, and correlated with peak VO2 (r = 0.58, P < 0.001). Alveolar oxygen tension was higher in patients at each stage than in controls. CONCLUSIONS: Patients with CHF have an increased ventilatory response at all stages of exercise. Although this is accompanied by an increase in VD/VT, there is hyperventilation relative to blood gases. It is more likely that the excessive ventilation is not due to a primary pulmonary pathology, but rather, the increase in dead space is likely to be a response to increased ventilation. PMID:9068397

  15. The divergent ventilatory and heart rate response to moderate hypercapnia in infants with apnoea of infancy

    PubMed Central

    Katz-Salamon, M.; Milerad, J.

    1998-01-01

    BACKGROUND—Inspired CO2 is a potent ventilatory stimulant exhibiting a paradoxical inhibitory effect on breathing at high concentrations. Severe respiratory depression as a result of CO2 rebreathing during sleep has been implicated as a possible trigger factor in sudden infant death syndrome (SIDS).
OBJECTIVE—To investigate the ventilatory and heart rate (HR) responses to inhaled CO2 in infants with apnoea of infancy, a group believed to be at increased risk of SIDS.
STUDY DESIGN—Thirty one infants with severe sleep related apnoea, 31 infants with mild recurrent apnoea, and 31 age and sex matched controls for the infants with severe sleep related apnoea were studied. HR was computed from digitised RR intervals, "ventilation" was recorded by inductance plethysmography, and PCO2 and PO2 were monitored by transcutaneous electrodes. The ventilatory and HR responses to CO2 were expressed as percentage increase in ventilation and change in HR/unit change in transcutaneous PCO2.
RESULTS—The mean increase in transcutaneous PCO2 during CO2 challenge (0.45 kPa = 3.4 mm Hg) resulted in a mean increase in ventilation of 291%/1 kPa (7.3 mm Hg) increase in transcutaneous PCO2, with no difference between the groups. A significant difference between infants with severe sleep related apnoea and mild recurrent apnoea versus controls (p < 0.02, p < 0.01, respectively) was found in their HR response to CO2 challenge: HR decreased in 12 severe sleep related apnoea infants and 10 infants with mild recurrent apnoea, but only in two controls.
CONCLUSION—Infants with apnoea of infancy frequently show a paradoxical decrease in HR during CO2 challenge, possibly because of an insufficient ability to mobilise cardiovascular defence mechanisms when challenged with hypercapnia.

 PMID:9875018

  16. Effect of Time of Day on the Relationship Between Lactate and Ventilatory Thresholds: A Brief Report

    PubMed Central

    Şekir, Ufuk; Özyener, Fadil; Gür, Hakan

    2002-01-01

    The purpose of this investigation was to study the effect of time of day on the relationship between lactate (LT) and ventilatory thresholds (VT) of pulmonary oxygen uptake (VO2). Seven moderately active male volunteers (26.3 ± 3.0 years, 1.74 ± 0.08 m, 76 ± 5 kg) performed a maximal incremental test (increases of 30 W every 2 min) on a cycle ergometer on consecutive days at 0900 h, 1400h and 1900 h in a randomized fashion. The anaerobic threshold was determined using both ventilatory gas analysis and blood lactate measures. Each of the following variables was recorded both at VT and the LT; heart rate (HR, beats.min-1), minute ventilation (VE, L.min-1), respiratory exchange ratio (RER), time to threshold (Time, sec), oxygen uptake (VO2, ml·kg-1.min-1) and VO2 as a percentage of maximal oxygen uptake (%VO2max). The correlations between VT and LT variables analyzed by Pearson product moment correlations for each time of day. ANOVA was used to compare the data obtained at different times of the day. There were no significant differences for the data related to time of day either for ventilatory gas analysis or lactate measurements. The correlation coefficients between VT and LT variables were moderate to high (r=0.56-0.94) for time of day. However, the correlations for HR, VO2, and %VO2max (r=0.81-0.94) were slightly stronger compared with Time, VE and RER (r=0.56-0.88). It was concluded that, the data at VT and LT were not influenced by time of day. PMID:24748845

  17. Metabolic and ventilatory responses to steady state exercise relative to lactate thresholds.

    PubMed

    Ribeiro, J P; Hughes, V; Fielding, R A; Holden, W; Evans, W; Knuttgen, H G

    1986-01-01

    The metabolic and ventilatory responses to steady state submaximal exercise on the cycle ergometer were compared at four intensities in 8 healthy subjects. The trials were performed so that, after a 10 min adaptation period, power output was adjusted to maintain steady state VO2 for 30 min at values equivalent to: (1) the aerobic threshold (AeT); (2) between the aerobic and the anaerobic threshold (AeTAnT); (3) the anaerobic threshold (AnT); and (4) between the anaerobic threshold and VO2max (AnTmax). Blood lactate concentration and ventilatory equivalents for O2 and CO2 demonstrated steady state values during the last 20 min of exercise at the AeT, AeAnT and AnT intensities, but increased progressively until fatigue in the AnTmax trial (mean time = 16 min). Serum glycerol levels were significantly higher at 40 min of exercise on the AeAnT and the AnT when compared to AeT, while the respiratory exchange ratios were not significantly different from each other. Thus, metabolic and ventilatory steady state can be maintained during prolonged exercise at intensities up to and including the AnT, and fat continues to be a major fuel source when exercise intensities are increased from the AeT to the AnT in steady state conditions. The blood lactate response to exercise suggests that, for the organism as a whole, anaerobic glycolysis plays a minor role in the energy release system at exercise intensities upt to and including the AnT during steady state conditions.

  18. Prediction values for the ventilatory capacity in male West Pakistani workers in the United Kingdom

    PubMed Central

    Malik, M. A.; Moss, E.; Lee, W. R.

    1972-01-01

    The ventilatory functions (forced vital capacity, forced expiratory volume in one second, and peak expiratory flow rate) of West Pakistani immigrants working near Manchester were measured. There were 198 `normal' healthy adult workers aged 25 to 60 years and 129 workers aged 16 to 24 years. The subjects were considered `normal' if they did not admit to persistent cough and phlegm. The regression equations on age and height for the two groups are presented together with the corresponding nomograms for the adult group. Ventilatory function reached its maximum between the ages of 25 and 30 years; smokers and dust-exposed subjects did not differ significantly from non-smokers and non-dust-exposed subjects (P>0·1). This was probably due to their relatively light smoking habits and the short duration of dust exposure. The effects of age, in workers over the age of 25 years, and the predominant effects of height on the FVC, FEV1·0, and PEFR are similar to those found in other studies. The ventilatory capacity of the subjects was found to be somewhat lower than that of Caucasians, about equal to that of Negroes living in America, and higher than that of Indians of Asian origin living in Guyana or of Bantu Negroes in South Africa. The predicted FEV1·0/FVC% in the West Pakistani subjects is a little higher than any calculated from the results of other authors, but its regression on age is consistent with the findings of other studies and, therefore, can be used in clinical practice to assess the pulmonary conductance. PMID:5083729

  19. Effect of long-term therapy with oral steroids on respiratory muscle function and ventilatory drive.

    PubMed

    Zanotti, E; Corsico, R; Rampulla, C; Ambrosino, N; Fracchia, C; Crotti, P; Rubini, F; Nava, S

    1993-01-01

    It has been shown that chronic oral steroid therapy (ST) does not induce respiratory muscle dysfunction in normal and asthmatic subjects. As corticosteroids are sometimes chronically used in the treatment of the patients with chronic obstructive pulmonary disease (COPD), the aim of our study was to verify whether ST could cause respiratory muscle impairment and, since ST also affects the central nervous system, whether ST could influence the ventilatory pattern. We retrospectively studied 12 COPD patients (group A), on long-term therapy (for at least 4 consecutive months, range 4-18 months) with an oral steroid, deflazacort, 15 mg.d-1. The subjects were strictly matched, with regard to age, sex, height, weight, forced expiratory volume in one second (FEV1), residual volume (RV), arterial oxygen tension (PaCO2), arterial carbon dioxide tension (PaCO2) and pH, with 12 COPD patients (Group B) who had never taken oral steroids. To assess respiratory muscle strength, we measured maximal inspiratory (MIP) and expiratory (MEP) pressures, while mouth occlusion pressure (P0.1) was employed to assess neuromuscular drive; ventilatory pattern and airway impedence were also evaluated. Effectiveness of ST was confirmed by the plasmatic levels of endogenous cortisol. No significant differences were observed between the two groups with regard to MIP (A 72.2 +/- 9.7 vs B: 70 +/- 7.2 cmH2O) and MEP (A 91.6 +/- 10.5 vs B 94.4 +/- 7.6 cmH2O) whilst P0.1 was significantly higher in group A (2.6 +/- 0.3 cmH2O) than in group B (1.8 +/- 0.1 cmH2O). No significant differences were found among all the ventilatory parameters, but the impedence was significantly higher in group A.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8472057

  20. Anaerobic threshold assessment through the ventilatory method during roller-ski skating testing: right or wrong?

    PubMed

    Fabre, Nicolas; Bortolan, Lorenzo; Pellegrini, Barbara; Zerbini, Livio; Mourot, Laurent; Schena, Federico

    2012-02-01

    This study aimed at questioning the validity of the ventilatory method to determine the anaerobic threshold (respiratory compensation point [RCP]) during an incremental roller-ski skating test to exhaustion. Nine elite crosscountry skiers were evaluated. The skiers carried out an incremental roller-ski test on a treadmill with the V2 skating technique. Ventilatory parameters were continuously collected breath by breath, thanks to a portable gas exchange measurement system. Poling signal was obtained using instrumented ski poles. For each stage, ventilatory and poling signals were synchronized and averaged. The poor coefficient of interobserver reliability for the time at RCP confirmed the great difficulty felt by the 3 blinded reviewers for the RCP determination. Moreover, the reviewer agreed with the impossibility of determining RCP in 4 of the 9 skiers. There was no significant difference between breathing frequency (Bf) and poling frequency (Pf) during the last 8 stages. However, it seems that the differences observed during the first stages arose from the use of either a strictly 1:1 or a 1:2 Bf to Pf ratio when the exercise intensity was still moderate. So, even if there were significant differences between the frequencies, the Bf was strictly subordinate to the Pf during the entire test. In the same way, the normalized tidal volume and peak poling forces curves were superposable. These findings showed that when the upper body is mainly involved in the propulsion, the determinants of the ventilation are strictly dependent on the poling pattern during an incremental test to exhaustion. Thus, during roller-ski skating, the determination of RCP must be used cautiously because too much depending on mechanical factors.

  1. Sonotubometry, a useful tool for the evaluation of the Eustachian tube ventilatory function

    PubMed Central

    Borangiu, A; Popescu, CR; Purcarea, VL

    2014-01-01

    From the three Eustachian tube (ET) functions: middle ear protection, secretion clearance and middle ear ventilation, the ventilatory function is unanimously considered the most important one, because proper hearing is established only when tympanic membrane compliance is normal. This requires equilibrium between the middle ear and ambient gas pressure, which makes the normal functioning of active ET opening of critical importance. There are several methods and tests that can assess such a complex and variable mechanism. Sonotubometry is one such method; despite the fact that it has been continuously improved in the last 20 years, it is not yet systematically used to evaluate the ET ventilatory function, because its measurement pattern, context mapping (patient, clinic data, medication, treatment), validation, reproducibility and value for clinic practice, have not yet been fully consolidated and integrated in a knowledge-based, service-oriented system, that can provide decision support or even diagnostic. The paper reviews the role of tubal sonometry as a non-invasive, physiologic and easy to use method in assessing the ventilatory function and investigates the validity and reproducibility of a measuring pattern and test in a group of children. The paper describes the test pattern used, and the computer-based platform based on: (1) Digital Signal Processing (DSP) for sound acquisition and low-level processing; (2) Artificial Intelligence techniques to extract significant sound features from sonotubograms and learn a manifold context database. Results are reported from test series carried out in healthy children; a similar study between tests is included in the final Discussions section. PMID:25713631

  2. Validity and Reliability of Ventilatory and Blood Lactate Thresholds in Well-Trained Cyclists

    PubMed Central

    Pallarés, Jesús G.; Morán-Navarro, Ricardo; Ortega, Juan Fernando; Fernández-Elías, Valentín Emilio; Mora-Rodriguez, Ricardo

    2016-01-01

    Purpose The purpose of this study was to determine, i) the reliability of blood lactate and ventilatory-based thresholds, ii) the lactate threshold that corresponds with each ventilatory threshold (VT1 and VT2) and with maximal lactate steady state test (MLSS) as a proxy of cycling performance. Methods Fourteen aerobically-trained male cyclists (V˙O2max 62.1±4.6 ml·kg-1·min-1) performed two graded exercise tests (50 W warm-up followed by 25 W·min-1) to exhaustion. Blood lactate, V˙O2 and V˙CO2 data were collected at every stage. Workloads at VT1 (rise in V˙E/V˙O2;) and VT2 (rise in V˙E/V˙CO2) were compared with workloads at lactate thresholds. Several continuous tests were needed to detect the MLSS workload. Agreement and differences among tests were assessed with ANOVA, ICC and Bland-Altman. Reliability of each test was evaluated using ICC, CV and Bland-Altman plots. Results Workloads at lactate threshold (LT) and LT+2.0 mMol·L-1 matched the ones for VT1 and VT2, respectively (p = 0.147 and 0.539; r = 0.72 and 0.80; Bias = -13.6 and 2.8, respectively). Furthermore, workload at LT+0.5 mMol·L-1 coincided with MLSS workload (p = 0.449; r = 0.78; Bias = -4.5). Lactate threshold tests had high reliability (CV = 3.4–3.7%; r = 0.85–0.89; Bias = -2.1–3.0) except for DMAX method (CV = 10.3%; r = 0.57; Bias = 15.4). Ventilatory thresholds show high reliability (CV = 1.6%–3.5%; r = 0.90–0.96; Bias = -1.8–2.9) except for RER = 1 and V-Slope (CV = 5.0–6.4%; r = 0.79; Bias = -5.6–12.4). Conclusions Lactate threshold tests can be a valid and reliable alternative to ventilatory thresholds to identify the workloads at the transition from aerobic to anaerobic metabolism. PMID:27657502

  3. [Dyspnea caused by bullae in a muscular dystrophy patient on chronic intermittent ventilatory support].

    PubMed

    van Santen, G; Meuzelaar, J J; Tulleken, J E; Zijlstra, J G; Meinesz, A F; van der Werf, T S

    1999-12-11

    A 65-year-old patient, ex-smoker, with facioscapulohumeral muscular dystrophy (FSHD) had been on home non invasive ventilatory support for three years when he experienced gradual increase of dyspnoea. The chest radiograph showed large bullae occupying most of the right hemithorax, with compression of lung tissue, mediastinal shift, and compression of the left lower lobe. Bullectomy resulted in rapid clinical and radiographic improvement. This is the first report of beneficial effects of emergency bullectomy in FSHD. Bullectomy has proved most successful in patients with localized bullae and compression of surrounding lung tissue. Patients with respiratory infections and bronchiectasis benefit less. PMID:10627757

  4. Effect of CO₂ on the ventilatory sensitivity to rising body temperature during exercise.

    PubMed

    Hayashi, Keiji; Honda, Yasushi; Miyakawa, Natsuki; Fujii, Naoto; Ichinose, Masashi; Koga, Shunsaku; Kondo, Narihiko; Nishiyasu, Takeshi

    2011-05-01

    We examined the degree to which ventilatory sensitivity to rising body temperature (the slope of the regression line relating ventilation and body temperature) is altered by restoration of arterial PCO(2) to the eucapnic level during prolonged exercise in the heat. Thirteen subjects exercised for ~60 min on a cycle ergometer at 50% of peak O(2) uptake with and without inhalation of CO(2)-enriched air. Subjects began breathing CO(2)-enriched air at the point that end-tidal Pco(2) started to decline. Esophageal temperature (T(es)), minute ventilation (V(E)), tidal volume (V(T)), respiratory frequency (f(R)), respiratory gases, middle cerebral artery blood velocity, and arterial blood pressure were recorded continuously. When V(E), V(T), f(R), and ventilatory equivalents for O(2) uptake (V(E)/VO(2)) and CO(2) output (V(E)/VCO(2)) were plotted against changes in T(es) from the start of the CO(2)-enriched air inhalation (ΔT(es)), the slopes of the regression lines relating V(E), V(T), V(E)/VO(2), and V(E)/VCO(2) to ΔT(es) (ventilatory sensitivity to rising body temperature) were significantly greater when subjects breathed CO(2)-enriched air than when they breathed room air (V(E): 19.8 ± 10.3 vs. 8.9 ± 6.7 l·min(-1)·°C(-1), V(T): 18 ± 120 vs. -81 ± 92 ml/°C; V(E)/VO(2): 7.4 ± 5.5 vs. 2.6 ± 2.3 units/°C, and V(E)/VCO(2): 7.6 ± 6.6 vs. 3.4 ± 2.8 units/°C). The increase in Ve was accompanied by increases in V(T) and f(R). These results suggest that restoration of arterial PCO(2) to nearly eucapnic levels increases ventilatory sensitivity to rising body temperature by around threefold.

  5. Areas of the brain concerned with ventilatory load compensation in awake man

    PubMed Central

    Isaev, Gennadi; Murphy, Kevin; Guz, Abraham; Adams, Lewis

    2002-01-01

    There is broad agreement that the awake human ventilatory response to a moderate inspiratory load consists of a prolongation of inspiratory time (TI) with a maintenance of tidal volume (VT) and end-tidal PCO2 (PET,CO2), the response being severely blunted in sleep. There is no agreement on the mechanisms underlying this ventilatory response. Six naive healthy males (aged 39–44) were studied supine with their heads in a positron emission tomography (PET) scanner to allow relative regional cerebral blood flow (rCBF) to be measured with H215O given intravenously. A linearised resistive load (24 cmH2O (l s−1)−1) could be added to the inspiratory limb of a breathing valve inserted into a tightly fitting facemask; inspiratory flow was measured with a pneumotachograph. The load was applied, without alerting the subject, when the radioactivity first reached the head. Six scans were performed with and without the load, in each subject. Relative rCBF contrasts between the loaded and unloaded breathing states showed significant activations in inferior parietal cortex, prefrontal cortex, midbrain, basal ganglia and multiple cerebellar sites. No activations were found in the primary sensorimotor cortex. The findings suggest that there is a pattern of motor behavioural response to the uncomfortable sensation that inspiration is impeded. This results in a prolongation of TI, the maintenance of VT and a reduction in the degree of discomfort, presumably because of the reduction of mean negative pressure in the airways. PMID:11897862

  6. Ventilatory response to CO2. II. Studies in neurotic psychiatric patients and practitioners of transcendental meditation.

    PubMed

    Singh, B S

    1984-01-01

    The prominence of respiratory symptoms in patients with neurotic psychiatric disorders is noted and the literature on the control of respiration is reviewed to attempt to explain this finding. A previous study demonstrated a positive correlation between the ventilatory response to CO2 (S) and neurotic personality traits in a group of normal subjects. This study attempted to follow up this finding and hypothesized that a group of neurotically disturbed patients would have a higher S value and a group of individuals who practiced a calming technique such as transcendental meditation (TM) would have a lower S value than normal subjects. The second hypothesis was confirmed, but not the first, in that the neurotically disturbed patients had the lowest mean values for S of the three groups, rather than the highest. Particular characteristics of the sample of psychiatric patients cast doubt, however, on the validity of this finding. Three additional findings of this study were that anxious, depressive, and hyperventilating subject groups were no different from one another in terms of S values; that very experienced TM practitioners (sidhas) could significantly lower their ventilatory response to CO2 in the meditating state as compared to the nonmeditating alert state; and that the S value did not increase in two male subjects with endogenous depression after successful treatment with electroconvulsive therapy.

  7. Relationship between ventilatory function and age in master athletes and a sedentary reference population.

    PubMed

    Degens, Hans; Maden-Wilkinson, Thomas Mark; Ireland, Alex; Korhonen, Marko T; Suominen, Harri; Heinonen, Ari; Radak, Zsolt; McPhee, Jamie S; Rittweger, Jörn

    2013-06-01

    Ageing is accompanied with a decline in respiratory function. It is hypothesised that this may be attenuated by high physical activity levels. We performed spirometry in master athletes (71 women; 84 men; 35-86 years) and sedentary people (39 women; 45 men; 24-82 years), and calculated the predicted lung age (PLA). The negative associations of age with forced expiratory volume in 1 s (FEV1; 34 mL·year(-1)) and other ventilatory parameters were similar in controls and master athletes. FEV1pred was 9 % higher (P < 0.005) and PLA 15 % lower (P = 0.013) in athletes than controls. There were no significant differences between endurance and power athletes and sedentary people in maximal inspiratory and expiratory pressure. Neither age-graded performance nor weekly training hours were significantly related to lung age. Life-long exercise does not appear to attenuate the age-related decrease in ventilatory function. The better respiratory function in master athletes than age-matched sedentary people might be due to self-selection and attrition bias. PMID:22544616

  8. Inductive plethysmography potential as a surrogate for ventilatory measurements during rest and moderate physical exercise

    PubMed Central

    Cabiddu, Ramona; Pantoni, Camila B. F.; Mendes, Renata G.; Trimer, Renata; Catai, Aparecida M.; Borghi-Silva, Audrey

    2016-01-01

    Background: Portable respiratory inductive plethysmography (RIP) systems have been validated for ventilatory assessment during resting conditions and during incremental treadmill exercise. However, in clinical settings and during field-based exercise, intensity is usually constant and submaximal. A demonstration of the ability of RIP to detect respiratory measurements accurately during constant intensity conditions would promote and validate the routine use of portable RIP devices as an alternative to ergospirometry (ES), the current gold standard technique for ventilatory measures. Objective: To investigate the agreement between respiratory variables recorded by a portable RIP device and by ES during rest and constant intensity exercise. Method: Tidal volume (VT), respiratory rate (RR) and minute ventilation (VE) were concurrently acquired by portable RIP and ES in seven healthy male volunteers during standing rest position and constant intensity treadmill exercise. Results: Significant agreement was found between RIP and ES acquisitions during the standing rest position and constant intensity treadmill exercise for RR and during the standing rest position for VE. Conclusion: Our results suggest that portable RIP devices might represent a suitable alternative to ES during rest and during constant submaximal exercise. PMID:26982454

  9. Arousal and ventilatory responses to mild hypoxia in sleeping preterm infants.

    PubMed

    Verbeek, Marjan M A; Richardson, Heidi L; Parslow, Peter M; Walker, Adrian M; Harding, Richard; Horne, Rosemary S C

    2008-09-01

    A failure to adequately respond to hypoxia has been implicated in the Sudden Infant Death Syndrome (SIDS). Preterm infants are at increased risk for SIDS, thus we compared ventilatory and arousal responses to mild hypoxia [15% oxygen (O2)] in preterm and term infants. Eight preterm and 15 term infants were serially studied with daytime polysomnography during which nasal airflow was monitored by pneumotachograph at 2-5 weeks, 2-3 and 5-6 months. At each age, in both groups, hypoxia induced a significant decrease in oxygen saturation (SpO2) during both active sleep (AS) and quiet sleep (QS). Infants invariably aroused in AS; and in QS either aroused or failed to arouse. In preterm infants arousal latency in AS was longer than in term infants (P < 0.05) at 2-5 weeks. Compared with term infants, preterm infants reached significantly lower SpO2 levels at 2-5 weeks in both AS and QS non-arousing tests and at 2-3 months in QS. A biphasic hypoxic ventilatory response was observed in QS non-arousing tests in both groups of infants at all three ages. We conclude that the greater desaturation during a hypoxic challenge combined with the longer arousal latency in preterm infants could contribute to greater risk for SIDS. PMID:18503514

  10. Ventilatory and intrapulmonary chemoreceptor sensitivity to CO2 in the burrowing owl.

    PubMed

    Kilgore, D L; Faraci, F M; Fedde, M R

    1985-12-01

    We measured the ventilatory response of anesthetized, unidirectionally ventilated pigeons and burrowing owls to changes in intrapulmonary CO2 concentration and the static CO2 sensitivity of intrapulmonary chemoreceptors (IPC) in these species and the domestic goose. Compared with pigeons, burrowing owls showed a significantly reduced respiratory frequency and amplitude response to increases in FICO2 from 0.05 to 0.10, which corroborates similar findings in intact, awake individuals of the same species. The average static CO2 sensitivity of IPC in geese, pigeons, and burrowing owls, as reflected by the average slope of the linear regressions of receptor discharge frequency on ln(PICO2), was -7.96, -11.1 and -6.87 imp/sec . ln(PICO2), respectively. The sensitivities of individual receptors were normally distributed in geese and pigeons, but skewed in burrowing owls. Therefore, the median CO2 sensitivity [-5.50 imp/sec . ln(PICO2)] is a more appropriate measure of the typical CO2 sensitivity of IPC in burrowing owls. The static CO2 sensitivity of IPC in burrowing owls is the lowest reported for euthermic birds with a normal acid-base balance and may materially contribute to the blunted ventilatory response of these birds to the elevated CO2 levels they encounter in nature. PMID:3937191

  11. T3 supplementation affects ventilatory timing & glucose levels in type 2 diabetes mellitus model.

    PubMed

    Bollinger, Stephen S; Weltman, Nathen Y; Gerdes, A Martin; Schlenker, Evelyn H

    2015-01-01

    Type II diabetes mellitus (T2DM) can affect ventilation, metabolism, and fasting blood glucose levels. Hypothyroidism may be a comorbidity of T2DM. In this study T2DM was induced in 20 female Sprague Dawley rats using Streptozotocin (STZ) and Nicotinamide (N). One of experimental STZ/N groups (N=10 per group) was treated with a low dose of triiodothyronine (T3). Blood glucose levels, metabolism and ventilation (in air and in response to hypoxia) were measured in the 3 groups. STZ/N-treated rats increased fasting blood glucose compared to control rats eight days and 2 months post-STZ/N injections indicating stable induction of T2DM state. Treatments had no effects on ventilation, metabolism or body weight. After one month of T3 supplementation, there were no physiological indications of hyperthyroidism, but T3 supplementation altered ventilatory timing and decreased blood glucose levels compared to STZ/N rats. These results suggest that low levels of T3 supplementation could offer modest effects on blood glucose and ventilatory timing in this T2M model.

  12. Effect of Same-day Sequential Exposure to Nitrogen Dioxide and Ozone on Cardiac and Ventilatory Function in Mice

    EPA Science Inventory

    This study examines the cardiac and ventilatory effects of sequential exposure to nitrogen dioxide and then ozone. The data show that mice exposed to both gases have increased arrhythmia and breathing changes not observed in the other groups. Although the mechanisms underlying ai...

  13. EFFECTS OF INDUCED RESPIRATORY CHANGES ON CARDIAC, VENTILATORY, AND THERMOREGULATORY PARAMETERS IN HEALTHY SPRAGUE-DAWLEY RATS

    EPA Science Inventory


    EFFECTS OF INDUCED RESPIRATORY CHANGES ON CARDIAC, VENTILATORY, AND THERMOREGULATORY PARAMETERS IN HEALTHY SPRAGUE-DAWLEY RATS. LB Wichers1, WH Rowan2, DL Costa2, MJ Campen3 and WP Watkinson2 1UNC SPH, Chapel Hill, NC, USA; 2USEPA, ORD/NHEERL/ETD/PTB, RTP, NC, USA; 3LRRI, A...

  14. Bronchitis in two integrated steel works: III. Respiratory symptoms and ventilatory capacity related to atmospheric pollution

    PubMed Central

    Lowe, C. R.; Campbell, H.; Khosla, T.

    1970-01-01

    Lowe, C. R., Campbell, H., and Khosla, T.(1970).Brit. J. industr. Med.,27, 121-129. Bronchitis in two integrated steel works. III. Respiratory symptoms and ventilatory capacity related to atmospheric pollution. This is the third in a series of papers presenting the results of an epidemiological study of respiratory symptomatology and lung function among men employed in two integrated steel works in South Wales. In this paper measurements of atmospheric pollution are related to respiratory symptoms and ventilatory capacity among 10 449 men who spent the greater part of their working hours in one or other of 114 defined working areas. The problem has been explored in three different ways. In the first, each man was assigned the mean value of sulphur dioxide and respirable dust for the area in which he was working and this was related to his ventilatory capacity (FEV1·0), age, smoking habits, and the number of years he had spent in his present department. In the second, the 114 working areas were divided into four sub-groups, according to defined levels of atmospheric pollution, and the prevalence of chronic bronchitis and mean FEV1·0 in the four sub-groups was examined. In the third way, the mean atmospheric pollution levels in each of the 114 areas were related to the prevalence of bronchitis and to the mean FEV1·0, age, and smoking habits in those areas. The analysis demonstrates very clearly the over-riding importance of cigarette smoking in the aetiology of chronic bronchitis, but, so far as the main purpose of the survey is concerned, it is concluded that, if there is any relation between respiratory disability and atmospheric pollution in the two steel works, it is so slight that none of the three approaches to the problem was sensitive enough to detect it. The implications of this are discussed in the light of the levels of pollution that were recorded in and around the two works. PMID:5428631

  15. Low-dose morphine elicits ventilatory excitant and depressant responses in conscious rats: Role of peripheral μ-opioid receptors.

    PubMed

    Henderson, Fraser; May, Walter J; Gruber, Ryan B; Young, Alex P; Palmer, Lisa A; Gaston, Benjamin; Lewis, Stephen J

    2013-08-01

    The systemic administration of morphine affects ventilation via a mixture of central and peripheral actions. The aims of this study were to characterize the ventilatory responses elicited by a low dose of morphine in conscious rats; to determine whether tolerance develops to these responses; and to determine the potential roles of peripheral μ-opioid receptors (μ-ORs) in these responses. Ventilatory parameters were monitored via unrestrained whole-body plethysmography. Conscious male Sprague-Dawley rats received an intravenous injection of vehicle or the peripherally-restricted μ-OR antagonist, naloxone methiodide (NLXmi), and then three successive injections of morphine (1 mg/kg) given 30 min apart. The first injection of morphine in vehicle-treated rats elicited an array of ventilatory excitant (i.e., increases in frequency of breathing, minute volume, respiratory drive, peak inspiratory and expiratory flows, accompanied by decreases in inspiratory time and end inspiratory pause) and inhibitory (i.e., a decrease in tidal volume and an increase in expiratory time) responses. Subsequent injections of morphine elicited progressively and substantially smaller responses. The pattern of ventilatory responses elicited by the first injection of morphine was substantially affected by pretreatment with NLXmi whereas NLXmi minimally affected the development of tolerance to these responses. Low-dose morphine elicits an array of ventilatory excitant and depressant effects in conscious rats that are subject to the development of tolerance. Many of these initial actions of morphine appear to involve activation of peripheral μ-ORs whereas the development of tolerance to these responses does not. PMID:24900948

  16. The effect of clothing on the initial ventilatory responses during cold-water immersion.

    PubMed

    Martin, S; Diewold, R J; Cooper, K E

    1978-10-01

    The effect of clothing on ventilatory responses during cold-water immersion was studied. Subjects were immersed in water at 13.9 degrees C on two occasions wearing either a bathing suit only or clothed with jacket, shirt, pants, and sports shoes. It was found that the initial gasp and subsequent minutes of expired ventilation were significantly attenuated, whereas the changes in end-tidal PCO2 were only significantly different for the 2nd and 3rd min of the immersion. It would appear that the use of clothing may prove beneficial during the first few minutes of a cold-water immersion by decreasing the powerful drive to increased respiration. PMID:709429

  17. The effect of inspiratory muscle fatigue on breathing pattern and ventilatory response to CO2.

    PubMed Central

    Mador, M J; Tobin, M J

    1992-01-01

    1. The effects of inducing inspiratory muscle fatigue on the subsequent breathing pattern were examined during resting unstimulated breathing and during CO2 rebreathing. In addition, we examined whether induction of inspiratory muscle fatigue alters CO2 responsiveness. 2. Global inspiratory muscle fatigue and diaphragmatic fatigue were achieved by having subjects breathe against an inspiratory resistive load while generating a predetermined fraction of either their maximal mouth pressure or maximal transdiaphragmatic pressure until they were unable to generate the target pressure. 3. Induction of inspiratory muscle fatigue had no effect on the subsequent breathing pattern during either unstimulated breathing or during CO2 rebreathing. 4. Following induction of inspiratory muscle fatigue, the slope of the ventilatory response to CO2 was significantly decreased from 18.8 +/- 3.3 during control to 13.8 +/- 2.1 l min-1 (% end-tidal CO2 concentration)-1 with fatigue (P < 0.02). PMID:1484352

  18. The effect of obesity on ventilatory response and anaerobic threshold during exercise.

    PubMed

    Sakamoto, S; Ishikawa, K; Senda, S; Nakajima, S; Matsuo, H

    1993-08-01

    To facilitate making the physical fitness programs for obesity control, we investigated the effects of obesity on the ventilatory response during exercise and exercise tolerance. One hundred eighteen adults were divided into a normal group and fatty group by percentage of body fat. Each subject performed a submaximal exercise test under the gas-exchange measurement. The fatty group was inferior to the normal group in exercise tolerance. The respiratory mode, during exercise, in the fatty group was characterized by higher respiratory rate and less tidal volume compared with the normal group. This mode may result in increased dead space and therefore unavailable ventilation capacity. These data suggest that the characteristic respiratory mode in the fatty group was a factor in the lower exercise tolerance.

  19. The effect of ozone inhalation on metabolic functioning of vascular endothelium and on ventilatory function

    SciTech Connect

    Gross, K.B.; White, H.J.; Sargent, N.E. )

    1991-06-15

    The primary purpose of this research was to determine the effect of ozone inhalation on pulmonary vascular endothelium. Male Fischer-344 rats were exposed to 0.5 or 0.7 ppm ozone, 20 hr/day for 7 days. Lungs were excised and perfused with Krebs medium containing (14C)serotonin or (14C)hippurylhistidylleucine (HHL). When compared to controls, the animals exposed to the lower ozone concentration showed no statistically significant changes in serotonin removal. In contrast, the higher ozone concentration resulted in a 32% decrease (p less than 0.0001) in serotonin removal, but had no effect on HHL. Rats similarly exposed to 0.7 ppm ozone but allowed to recover for 14 days in clean air showed no decrease in serotonin removal compared to their controls. Animals exposed sequentially to 0.5 ppm ozone for 7 days and then to 0.7 ppm for 7 days showed no alteration in serotonin metabolism, suggesting the development of tolerance initiated by the lower dose. After 7 days exposure to 0.7 ppm ozone, lung ventilatory function measurements revealed small though significant decreases in several parameters. Electron microscopic evaluation of lung capillary endothelium from animals exposed to the 0.7 ppm ozone showed no changes. Positive control animals exposed to greater than 95% oxygen, 20 hr/day for 2 days showed a 23% decrease in serotonin removal (p less than 0.03) and a 12% decrease in HHL removal (p less than 0.017). These studies indicate that inhalation of ozone can induce functional alterations in the lung endothelium, and that this effect occurs at a dosage of ozone that produces minimal ventilatory changes and no observable endothelial ultrastructural changes.

  20. Influence of developmental nicotine exposure on the ventilatory and metabolic response to hyperthermia.

    PubMed

    Ferng, Jonathan; Fregosi, Ralph F

    2015-12-01

    To determine whether developmental nicotine exposure (DNE) alters the ventilatory and metabolic response to hyperthermia in neonatal rats (postnatal age 2-4 days), pregnant dams were exposed to nicotine (6 mg kg(-1) of nicotine tartrate daily) or saline with an osmotic mini-pump implanted subdermally on day 5 of gestation. Rat pups (a total of 72 controls and 72 DNE pups) were studied under thermoneutral conditions (chamber temperature 33°C) and during moderate thermal stress (37.5°C). In all pups, core temperature was similar to chamber temperature, with no treatment effects. The rates of pulmonary ventilation (V̇(I)), O2 consumption (V̇(O2)) and CO2 production (V̇(CO2)) did not change with hyperthermia in either control or DNE pups. However, V̇(I) was lower in DNE pups at both chamber temperatures, whereas the duration of spontaneous apnoeas was longer in DNE pups than in controls at 33°C. The V̇(I)/V̇(O2) ratio increased at 37.5°C in control pups, although it did not change in DNE pups. To simulate severe thermal stress, additional pups were studied at 33°C and 43°C. V̇(I) increased with heating in control pups but not in DNE pups. As heat stress continued, gasping was evoked in both groups, with no effect of DNE on the gasping pattern. Over a 20 min recovery period at 33°C, V̇(I) returned to baseline in control pups but remained depressed in DNE pups. In addition to altering baseline V̇(I) and apnoea duration, DNE is associated with subtle but significant alterations in the ventilatory response to hyperthermia in neonatal rats. PMID:26427762

  1. Withdrawal of ventilatory support outside the intensive care unit: guidance for practice

    PubMed Central

    Laddie, Joanna; Craig, Finella; Brierley, Joe; Kelly, Paula; Bluebond-Langner, Myra

    2014-01-01

    Objective To review the work of one tertiary paediatric palliative care service in facilitating planned withdrawal of ventilatory support outside the intensive care setting, with the purpose of developing local guidance for practice. Methods Retrospective 10-year (2003–2012) case note review of intensive care patients whose parents elected to withdraw ventilation in another setting. Demographic and clinical data revealed common themes and specific incidents relevant to local guideline development. Results 18 children (aged 2 weeks to 16 years) were considered. Three died prior to transfer. Transfer locations included home (5), hospice (8) and other (2). Primary pathologies included malignant, neurological, renal and respiratory diseases. Collaborative working was evidenced in the review including multidisciplinary team meetings with the palliative care team prior to discharge. Planning included development of symptom management plans and emergency care plans in the event of longer than anticipated survival. Transfer of children and management of extubations demonstrated the benefits of planning and recognition that unexpected events occur despite detailed planning. We identified the need for local written guidance supporting healthcare professionals planning and undertaking extubation outside the intensive care setting, addressing the following phases: (i) introduction of withdrawal, (ii) preparation pretransfer, (iii) extubation, (iv) care postextubation and (v) care postdeath. Conclusions Planned withdrawal of ventilatory support outside the intensive care setting is challenging and resource intensive. The development of local collaborations and guidance can enable parents of children dependent on intensive care to consider a preferred place of death for their child, which may be outside the intensive care unit. PMID:24951460

  2. Effects of prenatal cocaine on the ventilatory response to hypoxia in newborn rabbits.

    PubMed

    Weese-Mayer, D E; Klemka-Walden, L M; Barkov, G A; Gingras, J L

    1992-01-01

    Recently, investigators have reported an alteration of postnatal respiratory pattern, deficient hypoxic arousal from sleep, and an increased incidence of sudden infant death syndrome (SIDS) among human infants exposed to cocaine prenatally, thus suggesting that prenatal cocaine exposure may perturb the maturation of respiratory control thereby increasing the risk for SIDS. To investigate the effects of prenatal cocaine on postnatal respiration, we evaluated the ventilatory response to 0.21 FIO2 (baseline) and at 0.15, 0.10, and 0.08 FIO2 by the barometric method on days 4-5 of life in 23 New Zealand White rabbit pups born to cocaine-exposed (30 mg/kg/day of cocaine HCl by continuous subcutaneous infusion), pair-fed and free-fed does. The chamber pressure deflection (proportional to VT after appropriate calculation) was computer-sampled at 200 Hz when the unanesthetized pups were resting quietly with no gross body movements. Recording was made after 10 min acclimatization to a specific FIO2. We found that baseline ventilation did not differ significantly among study groups. However, minute ventilation (VI), inspiratory flow (VT/TI), tidal volume (VT), increased significantly with hypoxia to peak values at 0.08 FIO2 in pair-fed and free-fed pups but these measurements did not increase significantly in cocaine-exposed pups. Our finding of a deficient second phase of the hypoxic ventilatory response among cocaine-exposed pups supports the hypothesis that prenatal cocaine perturbs the maturation of respiratory control.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1483357

  3. Weight loss associated with exercise training restores ventilatory efficiency in obese children.

    PubMed

    Prado, D M; Silva, A G; Trombetta, I C; Ribeiro, M M; Nicolau, C M; Guazzelli, I C; Matos, L N; Negrao, C E; Villares, S M

    2009-11-01

    The purpose of this study was to test the hypothesis that in obese children: 1) Ventilatory efficiency (VentE) is decreased during graded exercise; and 2) Weight loss through diet alone (D) improves VentE, and 3) diet associated with exercise training (DET) leads to greater improvement in VentE than by D. Thirty-eight obese children (10+/-0.2 years; BMI >95th percentile) were randomly divided into two study groups: D (n=17; BMI=30+/-1 kg/m (2)) and DET (n=21; 28+/-1 kg/m (2)). Ten lean children were included in a control group (10+/-0.3 years; 17+/-0.5 kg/m (2)). All children performed maximal treadmill testing with respiratory gas analysis (breath-by-breath) to determine the ventilatory anaerobic threshold (VAT) and peak oxygen consumption (VO (2) peak). VentE was determined by the VE/VCO (2) method at VAT. Obese children showed lower VO (2) peak and lower VentE than controls (p<0.05). After interventions, all obese children reduced body weight (p<0.05). D group did not improve in terms of VO (2) peak or VentE (p>0.05). In contrast, the DET group showed increased VO (2) peak (p=0.01) and improved VentE (DeltaVE/VCO (2)=-6.1+/-0.9; p=0.01). VentE is decreased in obese children, where weight loss by means of DET, but not D alone, improves VentE and cardiorespiratory fitness during graded exercise.

  4. AltitudeOmics: impaired pulmonary gas exchange efficiency and blunted ventilatory acclimatization in humans with patent foramen ovale after 16 days at 5,260 m.

    PubMed

    Elliott, Jonathan E; Laurie, Steven S; Kern, Julia P; Beasley, Kara M; Goodman, Randall D; Kayser, Bengt; Subudhi, Andrew W; Roach, Robert C; Lovering, Andrew T

    2015-05-01

    A patent foramen ovale (PFO), present in ∼40% of the general population, is a potential source of right-to-left shunt that can impair pulmonary gas exchange efficiency [i.e., increase the alveolar-to-arterial Po2 difference (A-aDO2)]. Prior studies investigating human acclimatization to high-altitude with A-aDO2 as a key parameter have not investigated differences between subjects with (PFO+) or without a PFO (PFO-). We hypothesized that in PFO+ subjects A-aDO2 would not improve (i.e., decrease) after acclimatization to high altitude compared with PFO- subjects. Twenty-one (11 PFO+) healthy sea-level residents were studied at rest and during cycle ergometer exercise at the highest iso-workload achieved at sea level (SL), after acute transport to 5,260 m (ALT1), and again at 5,260 m after 16 days of high-altitude acclimatization (ALT16). In contrast to PFO- subjects, PFO+ subjects had 1) no improvement in A-aDO2 at rest and during exercise at ALT16 compared with ALT1, 2) no significant increase in resting alveolar ventilation, or alveolar Po2, at ALT16 compared with ALT1, and consequently had 3) an increased arterial Pco2 and decreased arterial Po2 and arterial O2 saturation at rest at ALT16. Furthermore, PFO+ subjects had an increased incidence of acute mountain sickness (AMS) at ALT1 concomitant with significantly lower peripheral O2 saturation (SpO2). These data suggest that PFO+ subjects have increased susceptibility to AMS when not taking prophylactic treatments, that right-to-left shunt through a PFO impairs pulmonary gas exchange efficiency even after acclimatization to high altitude, and that PFO+ subjects have blunted ventilatory acclimatization after 16 days at altitude compared with PFO- subjects.

  5. Noninvasive mechanical ventilation in chronic obstructive pulmonary disease and in acute cardiogenic pulmonary edema.

    PubMed

    Rialp Cervera, G; del Castillo Blanco, A; Pérez Aizcorreta, O; Parra Morais, L

    2014-03-01

    Noninvasive ventilation (NIV) with conventional therapy improves the outcome of patients with acute respiratory failure due to hypercapnic decompensation of chronic obstructive pulmonary disease (COPD) or acute cardiogenic pulmonary edema (ACPE). This review summarizes the main effects of NIV in these pathologies. In COPD, NIV improves gas exchange and symptoms, reducing the need for endotracheal intubation, hospital mortality and hospital stay compared with conventional oxygen therapy. NIV may also avoid reintubation and may decrease the length of invasive mechanical ventilation. In ACPE, NIV accelerates the remission of symptoms and the normalization of blood gas parameters, reduces the need for endotracheal intubation, and is associated with a trend towards lesser mortality, without increasing the incidence of myocardial infarction. The ventilation modality used in ACPE does not affect the patient prognosis.

  6. The ventilatory CO2 sensitivities from Read's rebreathing method and the steady-state method are not equal in man.

    PubMed Central

    Berkenbosch, A; Bovill, J G; Dahan, A; DeGoede, J; Olievier, I C

    1989-01-01

    1. The ventilatory response to changes in end-tidal carbon dioxide tension during hyperoxia, obtained with Read's rebreathing method and a steady-state technique, were compared. 2. In ten young male subjects, forty successful rebreathing and thirteen steady-state experiments were performed on thirteen different morning sessions. 3. In all subjects the ventilatory CO2 sensitivities obtained with the rebreathing method (Sr) were appreciably larger than the steady-state CO2 sensitivities (Ss). The ratio Sr/Ss ranged from 1.40 to 2.59 with a mean value of 1.85. 4. We argue that these results can be explained by considering the effect of changes in cerebral blood flow upon increasing the arterial CO2 tension during rebreathing and the steady state. 5. We conclude that in general the CO2 sensitivity obtained with Read's rebreathing method does not represent the steady-state CO2 sensitivity. PMID:2515274

  7. Heart rate deflection point relates to second ventilatory threshold in a tennis test.

    PubMed

    Baiget, Ernest; Fernández-Fernández, Jaime; Iglesias, Xavier; Rodríguez, Ferran A

    2015-03-01

    The relationship between heart rate deflection point (HRDP) and the second ventilatory threshold (VT2) has been studied in continuous sports, but never in a tennis-specific test. The aim of the study was to assess the relationships between HRDP and the VT2, and between the maximal test performance and the maximal oxygen uptake ((Equation is included in full-text article.)) in an on-court specific endurance tennis test. Thirty-five high-level tennis players performed a progressive tennis-specific field test to exhaustion to determine HRDP, VT2, and (Equation is included in full-text article.). Ventilatory gas exchange parameters were continuously recorded by a portable telemetric breath-by-breath gas exchange measurement system. Heart rate deflection point was identified at the point at which the slope values of the linear portion of the time/heart rate (HR) relationship began to decline and was successfully determined in 91.4% of the players. High correlations (r = 0.79-0.96; p < 0.001) between physiological (HR and oxygen uptake [(Equation is included in full-text article.)]) and performance (Time, Stage, and Frequency of balls [Ballf]) variables corresponding to HRDP and VT2 were observed. Frequency of balls at the HRDP (BallfHRDP) was detected at 19.8 ± 1.7 shots per minute. Paired t-test showed no significant differences in HR (178.9 ± 8.5 vs. 177.9 ± 8.7 b·min for HRDP vs. HRVT2, respectively) at intensities corresponding to HRDP and VT2. Maximal test performance and (Equation is included in full-text article.)were moderately correlated (r = 0.56; p < 0.001). Heart rate deflection point obtained from this specific tennis test can be used to determine the VT2, and the BallfHRDP can be used as a practical performance variable to prescribe on-court specific aerobic training at or near VT2. PMID:25162649

  8. Heart rate deflection point relates to second ventilatory threshold in a tennis test.

    PubMed

    Baiget, Ernest; Fernández-Fernández, Jaime; Iglesias, Xavier; Rodríguez, Ferran A

    2015-03-01

    The relationship between heart rate deflection point (HRDP) and the second ventilatory threshold (VT2) has been studied in continuous sports, but never in a tennis-specific test. The aim of the study was to assess the relationships between HRDP and the VT2, and between the maximal test performance and the maximal oxygen uptake ((Equation is included in full-text article.)) in an on-court specific endurance tennis test. Thirty-five high-level tennis players performed a progressive tennis-specific field test to exhaustion to determine HRDP, VT2, and (Equation is included in full-text article.). Ventilatory gas exchange parameters were continuously recorded by a portable telemetric breath-by-breath gas exchange measurement system. Heart rate deflection point was identified at the point at which the slope values of the linear portion of the time/heart rate (HR) relationship began to decline and was successfully determined in 91.4% of the players. High correlations (r = 0.79-0.96; p < 0.001) between physiological (HR and oxygen uptake [(Equation is included in full-text article.)]) and performance (Time, Stage, and Frequency of balls [Ballf]) variables corresponding to HRDP and VT2 were observed. Frequency of balls at the HRDP (BallfHRDP) was detected at 19.8 ± 1.7 shots per minute. Paired t-test showed no significant differences in HR (178.9 ± 8.5 vs. 177.9 ± 8.7 b·min for HRDP vs. HRVT2, respectively) at intensities corresponding to HRDP and VT2. Maximal test performance and (Equation is included in full-text article.)were moderately correlated (r = 0.56; p < 0.001). Heart rate deflection point obtained from this specific tennis test can be used to determine the VT2, and the BallfHRDP can be used as a practical performance variable to prescribe on-court specific aerobic training at or near VT2.

  9. Correlations between lactate and ventilatory thresholds and the maximal lactate steady state in elite cyclists.

    PubMed

    Van Schuylenbergh, R; Vanden Eynde, B; Hespel, P

    2004-08-01

    We investigated the validity of different lactate and ventilatory threshold methods, to estimate heart rate and power output corresponding with the maximal lactate steady-state (MLSS) in elite cyclists. Elite cyclists (n = 21; 21 +/- 0.4 y; VO2peak, 5.4 +/- 0.2 l x min (-1)) performed either one (n = 10) or two (n = 11) maximal graded exercise tests, as well as two to three 30-min constant-load tests to determine MLSS, on their personal race bicycle which was mounted on an ergometer. Initial workload for the graded tests was 100 Watt and was increased by either 5 % of body mass (in Watt) with every 30 s (T30 s), or 60 % of body mass (in Watt) with every 6 min (T6min). MLSS was defined as the highest constant workload during which lactate increased no more than 1 mmol x l (-1) from min 10 to 30. In T30 s and T6 min the 4 mmol (TH-La4), the Conconi (TH-Con) and dmax (TH-Dm) lactate threshold were determined. The dmax lactate threshold was defined as the point that yields the maximal distance from the lactate curve to the line formed by the lowest and highest lactate values of the curve. In T30 s also ventilatory (TH-Ve) and Vslope (TH-Vs) thresholds were calculated. Time to exhaustion was 36 +/- 1 min for T30 s versus 39 +/- 1 min for T6 min. None of the threshold measures in T30 s, except TH-Vs (r2 = 0.77 for heart rate) correlated with either MLSS heart rate or power output. During T6 min, power output at TH-Dm was closely correlated with MLSS power (r2=0.72). Low correlations were found between MLSS heart rate and heart rate measured at TH-Dm (r2=0.46) and TH-La4 (r2=0.25), respectively, during T6 min. It is concluded that it is not possible to precisely predict heart rate or power output corresponding with MLSS in elite cyclists, from a single graded exercise test causing exhaustion within 35-40 min. The validity of MLSS predicted from an incremental test must be verified by a 30-min constant-load test.

  10. Model-based stability assessment of ventilatory control in overweight adolescents with obstructive sleep apnea during NREM sleep.

    PubMed

    Nava-Guerra, L; Tran, W H; Chalacheva, P; Loloyan, S; Joshi, B; Keens, T G; Nayak, K S; Davidson Ward, S L; Khoo, M C K

    2016-07-01

    Obstructive sleep apnea (OSA) involves the interplay of several different factors such as an unfavorable upper airway anatomy, deficiencies in pharyngeal muscle responsiveness, a low arousal threshold, and ventilatory control instability. Although the stability of ventilatory control has been extensively studied in adults, little is known about its characteristics in the pediatric population. In this study, we developed a novel experimental setup that allowed us to perturb the respiratory system during natural non-rapid eye movement (NREM) sleep conditions by manipulating the inspiratory pressure, provided by a bilevel pressure ventilator, to induce sighs after upper airway stabilization. Furthermore, we present a modeling framework that utilizes the noninvasively measured ventilatory responses to the induced sighs and spontaneous breathing data to obtain representations of the processes involved in the chemical regulation of respiration and extract their stability characteristics. After validation with simulated data, the modeling technique was applied to data collected experimentally from 11 OSA and 15 non-OSA overweight adolescents. Statistical analysis of the model-derived stability parameters revealed a significantly higher plant gain and lower controller gain in the OSA group (P = 0.046 and P = 0.007, respectively); however, no differences were found in loop gain (LG) and circulatory time delay between the groups. OSA severity and LG, within the 0.03-0.04-Hz frequency band, were significantly negatively associated (r = -0.434, P = 0.026). Contrary to what has been found in adults, our results suggest that in overweight adolescents, OSA is unlikely to be initiated through ventilatory instability resulting from elevated chemical loop gain. PMID:27174926

  11. Acute respiratory failure following severe arsenic poisoning.

    PubMed

    Greenberg, C; Davies, S; McGowan, T; Schorer, A; Drage, C

    1979-11-01

    A 47-year-old man had an episode of severe respiratory failure after acute intoxication with arsenic. Features of the initial clinical presentation included nausea, vomiting, and diarrhea, acute psychosis, diffuse skin rash, and marked pancytopenia. A peripheral neuropathy then developed which resulted in severe weakness of all muscles of the limbs, the shoulder and pelvis girdles, and the trunk. The neuropathy continued to progress despite treatment with dimercaprol (BAL in oil). Five weeks after the initial exposure, the patient was no longer able to maintain adquate ventilation and required mechanical ventilatory support. Improvement in the patient's neuromuscular status permitted successful weaning from the ventilator after one month of mechanical ventilation. Long-term follow-up revealed no further respiratory difficulty and slow improvement in the strength of the peripheral muscles.

  12. Role of glutamate and serotonin on the hypoxic ventilatory response in high-altitude-adapted plateau Pika.

    PubMed

    Bai, Zhenzhong; Voituron, Nicolas; Wuren, Tana; Jeton, Florine; Jin, Guoen; Marchant, Dominique; Richalet, Jean-Paul; Ge, Ri-Li; Pichon, Aurélien P

    2015-07-01

    The highland "plateau Pika" is considered to be adapted to chronic hypoxia. We hypothesized that glutamate N-methyl-D-aspartate (NMDA) and non-NMDA receptors, nitric oxide (NO) synthase, and serotonin are involved in hypoxic ventilatory response (HVR) in Pikas. We tested the effects of NMDA (memantine) and non-NMDA receptors (DNQX) antagonists, NO synthase inhibitor (L-NAME), and selective serotonin reuptake inhibitors (fluoxetine) on ventilation and HVR in Pikas. Ventilatory parameters were measured before and after drug (or vehicle) injections in conscious Pikas at their natural living altitude (PIO2 86 mmHg) and after a hypoxic challenge (PIO2 57 mmHg, 3 min) to assess the influence of peripheral chemoreceptor on HVR. Minute ventilation (VI) and tidal volume (Vt) increased during hypoxic challenge after vehicle injection, whereas the Ti/Ttot ratio remained unchanged. The increase in VI and Vt observed with vehicle at PIO2-57, when compared with PIO2-86, was inhibited after memantine and fluoxetine injection, whereas the DNQX injection increased HVR. At PIO2-57, L-NAME induced an increase in the Ti/Ttot ratio when compared with vehicle. Therefore, the glutamate through NMDA-R/AMPA receptor bindings and serotonin pathway are implicated at the peripheral chemoreceptor level in HVR in Pikas. However, NO influences the ventilatory pattern of Pikas at their habitual living altitude.

  13. Efficacy of a Ventilatory Training Mask to Improve Anaerobic and Aerobic Capacity in Reserve Officers' Training Corps Cadets.

    PubMed

    Sellers, John H; Monaghan, Taylor P; Schnaiter, Jessica A; Jacobson, Bert H; Pope, Zachary K

    2016-04-01

    The purpose of this study was to examine the efficacy of a ventilatory training mask to improve anaerobic and aerobic fitness in reserve officers' training corps (ROTC) cadets. Seventeen ROTC cadets from a Midwest university completed pre- and postassessments consisting of anthropometry, a 30-second Wingate Anaerobic Test (WAnT), and a maximal aerobic capacity test (V[Combining Dot Above]O2max). A 6-week intervention training period was used during which time participants completed their mandatory physical training (PT) sessions. Participants were randomly assigned to either the experimental group (MASK; n = 9) or the control group (CON; n = 8). The ventilatory training masks were adjusted to simulate an altitude of 2,750 m. There was no significant effect (p ≤ 0.05) between groups on fatigue index, anaerobic capacity, peak power, V[Combining Dot Above]O2max, or time to exhaustion. These results suggest that the use of the ventilatory training mask during mandatory PT did not elicit superior aerobic or anaerobic adaptations in ROTC cadets. Therefore, it is recommended that more established simulated altitude training methods be used when incorporating intermittent hypoxic training.

  14. Heart rate response during a simulated Olympic boxing match is predominantly above ventilatory threshold 2: a cross sectional study.

    PubMed

    de Lira, Claudio Andre Barbosa; Peixinho-Pena, Luiz Fernando; Vancini, Rodrigo Luiz; de Freitas Guina Fachina, Rafael Júlio; de Almeida, Alexandre Aparecido; Andrade, Marília Dos Santos; da Silva, Antonio Carlos

    2013-01-01

    The present study aimed to describe heart rate (HR) responses during a simulated Olympic boxing match and examine physiological parameters of boxing athletes. Ten highly trained Olympic boxing athletes (six men and four women) performed a maximal graded exercise test on a motorized treadmill to determine maximal oxygen uptake (52.2 mL · kg(-1) · min(-1) ± 7.2 mL · kg(-1) · min(-1)) and ventilatory thresholds 1 and 2. Ventilatory thresholds 1 and 2 were used to classify the intensity of exercise based on respective HR during a boxing match. In addition, oxygen uptake (V̇O2) was estimated during the match based on the HR response and the HR-V̇O2 relationship obtained from a maximal graded exercise test for each participant. On a separate day, participants performed a boxing match lasting three rounds, 2 minutes each, with a 1-minute recovery period between each round, during which HR was measured. In this context, HR and V̇O2 were above ventilatory threshold 2 during 219.8 seconds ± 67.4 seconds. There was an increase in HR and V̇O2 as a function of round (round 3 < round 2 < round 1, P < 0.0001). These findings may direct individual training programs for boxing practitioners and other athletes. PMID:24379723

  15. Comparative ventilatory strategies of acclimated rats and burrowing plateau pika (Ochotona curzoniae) in response to hypoxic-hypercapnia.

    PubMed

    Pichon, Aurélien; Voituron, Nicolas; Bai, Zhenzhong; Jeton, Florine; Tana, Wuren; Marchant, Dominique; Jin, Guoen; Richalet, Jean-Paul; Ge, Ri-Li

    2015-09-01

    The objective of this study was to compare the different ventilatory strategies that help in coping with hypoxic-hypercapnia environment among two species: use acclimated rats and plateau pikas (Ochotona curzoniae) that live in Tibetan plateaus, and have been well adjusted to high altitude. Arterial blood samples taken at 4100 m of elevation in acclimatized rats and adapted pikas revealed inter-species differences with lower hemoglobin and hematocrit and higher blood pH in pikas. A linear and significant increase in minute ventilation was observed in pikas, which help them to cope with hypoxic-hypercapnia. Pikas also displayed a high inspiratory drive and an invariant respiratory timing regardless of the conditions. Biochemical analysis revealed that N-methyl-D-aspartate receptor (NMDA) receptor gene and nNOS gene are highly conserved between rats and pikas, however pikas have higher expression of NMDA receptors and nNOS compared to rats at the brainstem level. Taken together, these results suggest that pikas have developed a specific ventilatory pattern supported by a modification of the NMDA/NO ventilatory central pathways to survive in extreme conditions imposed on the Tibetan plateaus. These physiological adaptive strategies help in maintaining a better blood oxygenation despite high CO2 concentration in burrows at high altitude. PMID:25988712

  16. Heart rate response during a simulated Olympic boxing match is predominantly above ventilatory threshold 2: a cross sectional study.

    PubMed

    de Lira, Claudio Andre Barbosa; Peixinho-Pena, Luiz Fernando; Vancini, Rodrigo Luiz; de Freitas Guina Fachina, Rafael Júlio; de Almeida, Alexandre Aparecido; Andrade, Marília Dos Santos; da Silva, Antonio Carlos

    2013-01-01

    The present study aimed to describe heart rate (HR) responses during a simulated Olympic boxing match and examine physiological parameters of boxing athletes. Ten highly trained Olympic boxing athletes (six men and four women) performed a maximal graded exercise test on a motorized treadmill to determine maximal oxygen uptake (52.2 mL · kg(-1) · min(-1) ± 7.2 mL · kg(-1) · min(-1)) and ventilatory thresholds 1 and 2. Ventilatory thresholds 1 and 2 were used to classify the intensity of exercise based on respective HR during a boxing match. In addition, oxygen uptake (V̇O2) was estimated during the match based on the HR response and the HR-V̇O2 relationship obtained from a maximal graded exercise test for each participant. On a separate day, participants performed a boxing match lasting three rounds, 2 minutes each, with a 1-minute recovery period between each round, during which HR was measured. In this context, HR and V̇O2 were above ventilatory threshold 2 during 219.8 seconds ± 67.4 seconds. There was an increase in HR and V̇O2 as a function of round (round 3 < round 2 < round 1, P < 0.0001). These findings may direct individual training programs for boxing practitioners and other athletes.

  17. Heart rate response during a simulated Olympic boxing match is predominantly above ventilatory threshold 2: a cross sectional study

    PubMed Central

    de Lira, Claudio Andre Barbosa; Peixinho-Pena, Luiz Fernando; Vancini, Rodrigo Luiz; de Freitas Guina Fachina, Rafael Júlio; de Almeida, Alexandre Aparecido; Andrade, Marília dos Santos; da Silva, Antonio Carlos

    2013-01-01

    The present study aimed to describe heart rate (HR) responses during a simulated Olympic boxing match and examine physiological parameters of boxing athletes. Ten highly trained Olympic boxing athletes (six men and four women) performed a maximal graded exercise test on a motorized treadmill to determine maximal oxygen uptake (52.2 mL · kg−1 · min−1 ± 7.2 mL · kg−1 · min−1) and ventilatory thresholds 1 and 2. Ventilatory thresholds 1 and 2 were used to classify the intensity of exercise based on respective HR during a boxing match. In addition, oxygen uptake (V̇O2) was estimated during the match based on the HR response and the HR-V̇O2 relationship obtained from a maximal graded exercise test for each participant. On a separate day, participants performed a boxing match lasting three rounds, 2 minutes each, with a 1-minute recovery period between each round, during which HR was measured. In this context, HR and V̇O2 were above ventilatory threshold 2 during 219.8 seconds ± 67.4 seconds. There was an increase in HR and V̇O2 as a function of round (round 3 < round 2 < round 1, P < 0.0001). These findings may direct individual training programs for boxing practitioners and other athletes. PMID:24379723

  18. Relevance of Respiratory Symptoms and Signs to Ventilatory Capacity Changes after Exposure to Grain Dust and Phosphate Rock Dust

    PubMed Central

    Gandevia, Bryan; Ritchie, Blair

    1966-01-01

    Ventilatory capacity was measured before and after exposure to high concentrations of wheat dust in 24 men, 18 of whom were similarly studied while working with calcium phosphate rock. Changes in ventilatory capacity were examined in relation to respiratory symptoms as commonly elicited in occupational surveys, and to the presence or absence of a productive cough on request and under observation. A significant decrease in the forced expiratory volume at one second was observed within half an hour of beginning work in the wheat dust, and this decrease was maintained throughout the work shift. A smaller significant decrease was found on exposure to phosphate rock over several hours, no significant change occurring within the first half-hour. Greater or more consistent decreases were recorded in those men who gave a history of persistent cough and sputum, and more particularly in those who had a productive cough on request, than in those without these features. A history of symptoms on exposure failed to define a group showing any more severe ventilatory reaction on exposure to wheat dust than the average. Some of the factors influencing the history of symptoms in occupational populations are reviewed, and the advantage of an objective sign, as provided by a deliberate cough, is indicated in defining an `abnormal' group within such a population. PMID:5946127

  19. Physiological response to increasing levels of neurally adjusted ventilatory assist (NAVA).

    PubMed

    Lecomte, François; Brander, Lukas; Jalde, Fredrick; Beck, Jennifer; Qui, Haibo; Elie, Caroline; Slutsky, Arthur S; Brunet, Fabrice; Sinderby, Christer

    2009-04-30

    This study evaluated the response to increasing levels of neurally adjusted ventilatory assist (NAVA), a mode converting electrical activity of the diaphragm (EAdi) into pressure, regulated by a proportionality constant called the NAVA level. Fourteen rabbits were studied during baseline, resistive loading and ramp increases of the NAVA level. EAdi, airway (Paw) and esophageal pressure (Pes), Pes pressure time product (PTPes), breathing pattern, and blood gases were measured. Resistive loading increased PTPes and EAdi. P(a)(CO)(2) increased with high load but not during low load. Increasing NAVA levels increased Paw until a breakpoint where the Paw increase was reduced despite increasing NAVA level. At this breakpoint, Pes, PTPes, EAdi, and P(a)(CO)(2) were similar to baseline. Further increase of the NAVA level reduced Pes, PTPes and EAdi without changes in ventilation. In conclusion, observing the trend in Paw during a ramp increase of the NAVA level allows determination of a level where the inspiratory effort matches unloaded conditions. PMID:19429528

  20. Ventilatory and metabolic response to rebreathing the expired air in the snorkel.

    PubMed

    Toklu, A S; Kayserilioğlu, A; Unal, M; Ozer, S; Aktaş, S

    2003-04-01

    The snorkel, which allows swimmers to keep their face down in the water while breathing, is widely used by divers, spear fishermen and monofin swimmers. A snorkel adds an additional dead space of 160-170 ml and causes an increase in the concentration of CO2 in the inspired gas due to expired air trapped in the snorkel which is then re-inspired. In this study the metabolic and the ventilatory response to rebreathing the expired air in the snorkel were investigated in twelve human subjects. A 2900 C Sensor Medics gas analyzer was used in breath-by-breath mode for the measurements. Ventilation (VE), respiratory rate (RR), tidal volume (TV), oxygen consumption (.VO 2) and carbon dioxide production (.VCO 2) were measured at rest and during light exercise both with and without the snorkel dead space. We observed a significant increase in all variables except RR, when subjects rebreathed the gas in the snorkel. The increase in ventilation resulted from an increase in tidal volume rather than increasing respiratory rate. We conclude that the work of breathing is increased when CO2 concentration is high in inspired gas and re-breathing while snorkelling can be prevented by a new snorkel design with a low-resistance two-way non-rebreathing valve, which will allow the expired air flow into the water.

  1. Maturation of the initial ventilatory response to hypoxia in sleeping infants.

    PubMed

    Richardson, Heidi L; Parslow, Peter M; Walker, Adrian M; Harding, Richard; Horne, Rosemary S C

    2007-03-01

    In infants most previous studies of the hypoxic ventilatory response (HVR) have been conducted only during quiet sleep (QS) and arousal responses have not been considered. Our aim was to quantify the maturation of the HVR in term infants during both active sleep (AS) and QS over the first 6 months of life. Daytime polysomnography was performed on 15 healthy term infants at 2-5 weeks, 2-3 and 5-6 months after birth and infants were challenged with hypoxia (15% O2, balance N2). Tests in AS always resulted in arousal; in QS tests infants either aroused or did not arouse. A biphasic HVR was observed in non arousing tests at all three ages studied. The fall in SpO2 was more rapid in arousal tests at all three ages. At 2-5 weeks, in non-arousing QS tests, there was a greater fall in respiratory frequency (f) despite a smaller fall in SpO2 compared with 2-3 and 5-6 months. When infants aroused there was no difference in the HVR between sleep states or with postnatal age. However, when infants failed to arouse from QS, arterial desaturation was less in the younger infants despite a poorer HVR. We suggest that arousal in response to hypoxia, particularly in AS, is a vital survival mechanism throughout the first 6 months of life. PMID:17309771

  2. Double product break point estimates ventilatory threshold in individuals with type 2 diabetes

    PubMed Central

    Victor de Sousa, Caio; Sales, Marcelo Magalhães; Aguiar, Samuel da Silva; Boullosa, Daniel Alexandre; Rosa, Thiago dos Santos; Baldissera, Vilmar; Simões, Herbert Gustavo

    2016-01-01

    [Purpose] To verify the identification of the anaerobic threshold through the double product breakpoint (DPBP) method for individuals with type 2 diabetes. [Subjects and Methods] Nine individuals with T2D (7 females; age=63.2 ± 8.9 y) and 10 non-diabetic (ND) (7 females; age=58.3 ± 7.8 y) performed an incremental exercise test on a cycle ergometer. Heart rate (HR), blood pressure (BP) and expired gas were measured at the end of each stage. The ventilatory threshold (VT) and DPBP were considered as the exercise intensities above which an over proportional increases in VE and DP were observed in relation to increasing workload. [Results] No differences were observed between the workloads, HR and VO2 corresponding to the AT identified respectively by VT and DPBP. For the T2D, strong correlations between VT and DBPB workloads (r=0.853), HR (r=0.714), and VO2 (r=0.863) were found. These relationships were similar to those found for the control group (r=0.923; r=0.881; and r=0.863, respectively). [Conclusion] These results demonstrate that the DPBP enables for the prediction of AT and correlated well the VT in both the T2D and ND participants. PMID:27390414

  3. Ventilatory and occlusion-pressure responses to hypercapnia in divers and non-divers.

    PubMed

    Sherman, D; Eilender, E; Shefer, A; Kerem, D

    1980-03-01

    Ventilatory (VE/PCO2) and occlusion-pressure (P0.1/PCO2) responses to progressive hypercapnia (rebreathing method of Read (1)) were estimated in 20 normal subjects and 22 scuba divers. Indexes of CO2 sensitivity (slopes of response curves) and absolute response values under strong CO2 drive (PCO2 = 60 mmHg) were significantly lower in the diver group. Individual CO2 sensitivity did not correlate with either diving experience or current diving activity. Positively skewed (log-normal) frequency distribution curves of individual CO2 sensitivities were drawn for the divers and for a larger sample of normal controls (using data from other studies). All divers' values fell in the lower range of non-diver control values and about one-third were below the normal range (mean +/- 2 SD) for CO2 sensitivity. We concluded that our divers did not represent a distinct population different from the normal one but rather a group of normal healthy subjects with either an inherent or acquired relatively low CO2 response. The rebreathing technique is strongly advocated as a tool for investigating divers' CO2 sensitivity and its implications in underwater environments.

  4. A field study of the ventilatory response to ambient temperature and pressure in sport diving.

    PubMed

    Muller, F L

    1995-09-01

    This study reports on the relationship between minute ventilation (VE) and environmental variables of temperature (T) and pressure (P) during open water diving. The author conducted a total of 38 dives involving either a light (20 dives) or a moderate (18 dives) level of physical activity. Within each of these groups, P and T taken together accounted for about two thirds of the variance in the VE data. A very significant increase in VE was observed as T decreased (1 < T(degrees C) < 22), and the magnitude of this increase at a given pressure level was similar in the 'light' and the 'moderate' data sets. A second order observation, particularly notable at lower temperature, was the decrease in VE with increasing pressure under conditions of light work. Empirical functions of the from VE = A+B/P n[1 + exp(T - 8)/10], where A, B, and n are adjustable variables, could accommodate both data sets over the whole range of T and P. These results are the first obtained under actual diving conditions to provide evidence for interactions between P, T, and VE. Understanding the physiological mechanisms by which these interactions occur would assist in appreciation of the limitations imposed on scuba divers by the environmental conditions as they affect their ventilatory responses.

  5. Hypoxic ventilatory sensitivity in men is not reduced by prolonged hyperoxia (Predictive Studies V and VI)

    NASA Technical Reports Server (NTRS)

    Gelfand, R.; Lambertsen, C. J.; Clark, J. M.; Hopkin, E.

    1998-01-01

    Potential adverse effects on the O2-sensing function of the carotid body when its cells are exposed to toxic O2 pressures were assessed during investigations of human organ tolerance to prolonged continuous and intermittent hyperoxia (Predictive Studies V and VI). Isocapnic hypoxic ventilatory responses (HVR) were determined at 1.0 ATA before and after severe hyperoxic exposures: 1) continuous O2 breathing at 1.5, 2.0, and 2.5 ATA for 17.7, 9.0, and 5.7 h and 2) intermittent O2 breathing at 2.0 ATA (30 min O2-30 min normoxia) for 14.3 O2 h within 30-h total time. Postexposure curvature of HVR hyperbolas was not reduced compared with preexposure controls. The hyperbolas were temporarily elevated to higher ventilations than controls due to increments in respiratory frequency that were proportional to O2 exposure time, not O2 pressure. In humans, prolonged hyperoxia does not attenuate the hypoxia-sensing function of the peripheral chemoreceptors, even after exposures that approach limits of human pulmonary and central nervous system O2 tolerance. Current applications of hyperoxia in hyperbaric O2 therapy and in subsea- and aerospace-related operations are guided by and are well within these exposure limits.

  6. [Noninvasive ventilation: efficacy of a new ventilatory mode in patients with obesity-hypoventilation syndrome].

    PubMed

    Couillard, A; Pepin, J-L; Rabec, C; Cuvelier, A; Portmann, A; Muir, J-F

    2015-03-01

    Noninvasive ventilation is recommended to correct the nocturnal hypoventilation and relieve the symptoms of patients with the obesity-hypoventilation syndrome (OHS). The benefits of fixed pressure ventilation (S/T technology) are recognized but limited on account of the variability of nocturnal ventilatory requirements. The new technique AVAPS-AE (automatic EPAP) allows adjustment of the pressure according to the volume currently targeted. Its efficacy has not yet been evaluated. Our objectives are to evaluate firstly, whether AVAPS-AE optimizes the benefits of S/T technology on sleep architecture and quality, secondly, whether these benefits are associated with an improvement in gas exchange, symptoms, exercise tolerance, level of physical activity and quality of life of patients with OHS. In this multicenter trial, 60 newly diagnosed patients with OHS will be randomized to the control (S/T) and trial (AVAPS-AE) groups. A standardized titration procedure will be followed for the calibration of the ventilators. Functional evaluations (polysomnography, blood gases, impedance measurements and walking tests), questionnaires (physical activity, quality of life, quality of sleep and daytime somnolence) visual scales (fatigue, headaches) and a recording of activity will be undertaken after two months of ventilation. PMID:25847207

  7. Short term variability in FEV1 and bronchodilator responsiveness in patients with obstructive ventilatory defects.

    PubMed Central

    Tweeddale, P M; Alexander, F; McHardy, G J

    1987-01-01

    Short term variability in FEV1 and responsiveness to inhaled bronchodilator were measured in 150 patients with obstructive ventilatory defects. The range of initial FEV1 was 0.5-4.71 and the natural variability over a 20 minute period when expressed in absolute terms was similar over the entire range, and differed insignificantly from that found in normal subjects. The increase in FEV1 and vital capacity (VC) required to exclude natural variability with 95% confidence in these patients was 160 ml and 330 ml respectively. Natural variability when expressed in percentage terms was negatively correlated with the level of FEV1 recorded. The analysis of changes in FEV1 and VC after administration of bronchodilator used absolute and percentage criteria for response. The number of responders differed considerably according to the criterion used. In those defined by the absolute criterion as responders there was no evidence that size of response was related to level of FEV1. Percentage criteria have traditionally been used to identify responses to bronchodilator that may be clinically useful, while absolute criteria, although statistically valid, have not been favoured. Reappraisal of the criteria used and their limitations and implications is required. PMID:3438892

  8. Cystitis - acute

    MedlinePlus

    Uncomplicated urinary tract infection; UTI - acute; Acute bladder infection; Acute bacterial cystitis ... International clinical practice guidelines for the treatment of acute uncomplicated cystitis and pyelonephritis in women: A 2010 ...

  9. Noninvasive Positive Pressure Ventilation for Acute Respiratory Failure Patients With Chronic Obstructive Pulmonary Disease (COPD)

    PubMed Central

    McCurdy, BR

    2012-01-01

    ); and prevention of or treatment of recurrent respiratory failure in COPD patients after extubation from IMV. Clinical Need and Target Population Acute Hypercapnic Respiratory Failure Respiratory failure occurs when the respiratory system cannot oxygenate the blood and/or remove carbon dioxide from the blood. It can be either acute or chronic and is classified as either hypoxemic (type I) or hypercapnic (type II) respiratory failure. Acute hypercapnic respiratory failure frequently occurs in COPD patients experiencing acute exacerbations of COPD, so this is the focus of this evidence-based analysis. Hypercapnic respiratory failure occurs due to a decrease in the drive to breathe, typically due to increased work to breathe in COPD patients. Technology There are several treatment options for ARF. Usual medical care (UMC) attempts to facilitate adequate oxygenation and treat the cause of the exacerbation, and typically consists of supplemental oxygen, and a variety of medications such as bronchodilators, corticosteroids, and antibiotics. The failure rate of UMC is high and has been estimated to occur in 10% to 50% of cases. The alternative is mechanical ventilation, either invasive or noninvasive. Invasive mechanical ventilation involves sedating the patient, creating an artificial airway through endotracheal intubation, and attaching the patient to a ventilator. While this provides airway protection and direct access to drain sputum, it can lead to substantial morbidity, including tracheal injuries and ventilator-associated pneumonia (VAP). While both positive and negative pressure noninvasive ventilation exists, noninvasive negative pressure ventilation such as the iron lung is no longer in use in Ontario. Noninvasive positive pressure ventilation provides ventilatory support through a facial or nasal mask and reduces inspiratory work. Noninvasive positive pressure ventilation can often be used intermittently for short periods of time to treat respiratory failure, which

  10. Successful use of extracorporeal life support after double traumatic tracheobronchial injury in a patient with severe acute asthma.

    PubMed

    Valette, Xavier; Desjouis, Aurélie; Massetti, Massimo; Hanouz, Jean-Luc; Icard, Philippe

    2011-01-01

    We report the case of an asthmatic patient with blunt trachea and left main bronchus injuries who developed acute severe asthma after surgical repair. Despite medical treatment and ventilatory support, asthma persisted with high airway pressures and severe respiratory acidosis. We proposed venovenous extracorporeal life support for CO(2) removal which allowed arterial blood gas normalization and airway pressures decrease. Extracorporeal life support was removed on day five after medical treatment of acute severe asthma. So we report the successful use of extracorporeal life support for operated double blunt tracheobronchial injury with acute severe asthma. PMID:22135742

  11. Testosterone potentiates the hypoxic ventilatory response of adult male rats subjected to neonatal stress.

    PubMed

    Fournier, Sébastien; Gulemetova, Roumiana; Joseph, Vincent; Kinkead, Richard

    2014-05-01

    Neonatal stress disrupts development of homeostatic systems. During adulthood, male rats subjected to neonatal maternal separation (NMS) are hypertensive and show a larger hypoxic ventilatory response (HVR), with greater respiratory instability during sleep. Neonatal stress also affects sex hormone secretion; hypoxia increases circulating testosterone of NMS (but not control) male rats. Given that these effects of NMS are not observed in females, we tested the hypothesis that testosterone elevation is necessary for the stress-related increase of the HVR in adult male rats. Pups subjected to NMS were placed in an incubator for 3 h per day from postnatal day 3 to 12. Control pups remained undisturbed. Rats were reared until adulthood, and the HVR was measured by plethysmography (fractional inspired O2 = 0.12, for 20 min). We used gonadectomy to evaluate the effects of reducing testosterone on the HVR. Gonadectomy had no effect on the HVR of control animals but reduced that of NMS animals below control levels. Immunohistochemistry was used to quantify androgen receptors in brainstem areas involved in the HVR. Androgen receptor expression was generally greater in NMS rats than in control rats; the most significant increase was noted in the caudal region of the nucleus tractus solitarii. We conclude that the abnormal regulation of testosterone is important in stress-related augmentation of the HVR. The greater number of androgen receptors within the brainstem may explain why NMS rats are more sensitive to testosterone withdrawal. Based on the similarities of the cardiorespiratory phenotype of NMS rats and patients suffering from sleep-disordered breathing, these results provide new insight into its pathophysiology, especially sex-based differences in its prevalence.

  12. Gas exchange by intratracheal insufflation in a ventilatory failure dog model.

    PubMed Central

    Gavriely, N; Eckmann, D; Grotberg, J B

    1992-01-01

    Respiratory insufficiency patients who need only partial ventilatory support are, nevertheless, intubated and connected to a respirator. In search of a partial respiratory assistance method we evaluated the gas exchange, mechanisms, and hemodynamic effects of intratracheal insufflation (ITI) via a narrow (0.2-cm) catheter. The effects of flow rate (0.05-0.2 liter/min per kg), catheter tip position (carina, bronchus, and trachea), and superimposed chest vibration at 22 Hz were studied in seven anesthetized and partially paralyzed dogs. ITI in the carina induced CO2 removal (VCO2) of 48 +/- 16 ml/min in the periods between breaths, which was 39% of the control VCO2. CO2 removal rates between breaths with ITI in a bronchus and in the trachea were 63 and 28% of control, respectively (P < 0.05). ITI at 0.15-0.2 liter/min per kg augmented total VCO2 by > 50% over control (P < 0.05) and decreased PaCO2 by 10% (P < 0.05) despite a 28% fall in VE and 32% lower work of breathing (P < 0.05). Adding vibration to ITI at 0.15 liter/min per kg induced VCO2 of 162 +/- 34 ml/min, which was significantly greater than control, while PaCO2 fell from 69 +/- 24 to 47 +/- 6 mmHg (P < 0.05), despite complete cessation of spontaneous breathing. ITI with or without vibration did not cause any hemodynamic changes, except for a fall in the shunt fraction from 14.6 +/- 9.9% to 5.8 +/- 2.8% with vibration. Thus, ITI at low flow rates can support respiration with no hemodynamic side effects. Adding chest vibration further enhances gas exchange and can provide total ventilation. Images PMID:1469093

  13. Effect of exposures to ambient ozone on ventilatory lung function in children

    SciTech Connect

    Higgins, I.T.; D'Arcy, J.B.; Gibbons, D.I.; Avol, E.L.; Gross, K.B. )

    1990-05-01

    This study was undertaken to determine if the ventilatory capacity of children is affected by hourly concentrations of ozone inhaled during their daily activity. Over a 3-wk period children who were attending a summer camp in the San Bernardino mountains of California performed spirometry up to three times per day during their stay at the camp. Ozone, oxides of nitrogen, sulfur dioxide, temperature, and relative humidity were measured continuously. Daily average measurements of total suspended particulate and the PM10 particulate fraction were also made. Hourly ozone concentrations at the time of testing varied between 20 and 245 ppb. Regressions of each individual's FEV1 and FVC supported the view that high ozone levels reduced these lung function parameters. The average regression coefficient for FEV1 on ozone was -0.39 ml/ppb (SEM = 0.12) and for FVC -0.44 ml/ppb (SEM = 0.15), both of which were significantly different from zero. Statistical allowance for temperature and humidity increased the magnitude of these slopes. Nitrogen dioxide never exceeded 40 ppb during the time of testing and averaged 13 ppb. Sulfur dioxide's highest measurement was 8 ppb and often was at the limit of detection. Neither NO2 nor SO2 was considered in the statistical modeling. Data were divided based on whether each subject had been exposed to levels of ozone in excess of the National Ambient Air Quality Standard (NAAQS) during the several hours previous to being tested. Exposures exceeding the NAAQS indicated a significant negative relationship between ozone and FEV1, FVC, and PEFR. Data for nonexceedance periods did not indicate this negative relationship for any of the three lung function parameters, but it could not be determined if this was due to an absence of an ozone effect or to a combination of the increased variability and decreased size of this data subset.

  14. Maternal hypoxic ventilatory response, ventilation, and infant birth weight at 4,300 m.

    PubMed

    Moore, L G; Brodeur, P; Chumbe, O; D'Brot, J; Hofmeister, S; Monge, C

    1986-04-01

    To test the hypothesis that increased hypoxic ventilatory responsiveness (HVR) raised maternal ventilation and arterial oxygenation during high-altitude pregnancy and related to the birth weight of the offspring, we studied 21 residents of Cerro de Pasco, Peru (4,300 m), while eight of them were 36 +/- 0 wk pregnant and 15 of them 13 +/- 0 wk postpartum. HVR was low in the nonpregnant women (mean +/- SE shape parameter A = 23 +/- 8) but increased nearly fourfold with pregnancy (A = 87 +/- 17). The increase in HVR appeared to account for the 25% rise in resting ventilation with pregnancy (delta VE observed = 2.4 +/- 0.7 l/min BTPS vs. delta VE predicted from delta HVR = 2.6 +/- 1.7 l/min BTPS, P = NS). Hyperoxia decreased ventilation in the pregnant women (P less than 0.01) to levels similar to those measured when nonpregnant. The increased ventilation of pregnancy raised arterial O2 saturation (SaO2) from 83 +/- 1 to 87 +/- 0%, and SaO2 was correlated positively with HVR in the pregnant women. The rise in SaO2 compensated for a 0.9 g/100 ml decrease in hemoglobin concentration to preserve arterial O2 content at levels present when nonpregnant. Cardiac output in the 36th wk of pregnancy did not differ significantly from values measured postpartum. The increase in HVR correlated positively with infant birth weight. An increase in HVR may be an important contributor to increased maternal ventilation with pregnancy and infant birth weight at high altitude.

  15. Whole body plethysmography reveals differential ventilatory responses to ozone in rat models of cardiovascular disease.

    PubMed

    Dye, Janice A; Ledbetter, Allen D; Schladweiler, Mette C; Costa, Daniel L; Kodavanti, Urmila P

    2015-01-01

    To elucidate key factors of host susceptibility to air pollution, healthy and cardiovascular (CV)-compromised rats were exposed to air or ozone (O3) at 0.25, 0.5, or 1.0 ppm for 4 h. We hypothesized that rat strains with the least cardiac reserve would be most prone to develop significant health effects. Using flow whole body plethysmography (FWBP), ventilatory responses in healthy 3-month-old male rats [i.e. Wistar-Kyoto (WKY), Wistar (WIS), and Sprague-Dawley (SD) strains] were compared with hypertensive [i.e. spontaneously hypertensive (SH), fawn-hooded-hypertensive (FHH), and SH-stroke-prone (SHSP)] strains and obese [i.e. SH-heart failure-prone (SHHF) and JCR:LA-cp, atherosclerosis-prone (JCR)] strains. SH were slower to acclimate to the FWBP chambers. At 0-h post-air-exposure, SHSP and SHHF exhibited hyperpnea, indicative of cardiopulmonary insufficiency. At 0-h-post-O3, all but one strain showed significant concentration-dependent decreases in minute volume [MV = tidal volume (TV) × breathing frequency]. Comparing air with 1.0 ppm responses, MV declined 20-27% in healthy, 21-42% in hypertensive, and 33% in JCR rats, but was unchanged in SHHF rats. Penh increased significantly in all strains, with disproportionate increases in "responder" WKY and FHH strains. By 20 h, most changes had resolved, although Penh remained elevated in WKY, SH, and SHSP. Based on the effective dose estimates (O3 ppm × h × MV), the most CV-compromised (SHSP and SHHF) strains received significantly greater O3 lung deposition (25% and 40%, respectively). Data support epidemiologic associations that individuals with cardiopulmonary insufficiency are at greater risk for urban pollutant exposure due, in part, to enhanced lung deposition and exacerbation of hypoxia and pathophysiologic processes of heart failure. PMID:26667328

  16. Metabolic, ventilatory, and hygric physiology of the gracile mouse opossum (Gracilinanus agilis).

    PubMed

    Cooper, C E; Withers, P C; Cruz-Neto, A P

    2009-01-01

    We present the first complete study of basic laboratory-measured physiological variables (metabolism, thermoregulation, evaporative water loss, and ventilation) for a South American marsupial, the gracile mouse opossum (Gracilinanus agilis). Body temperature (T(b)) was thermolabile below thermoneutrality (T(b) = 33.5 degrees C), but a substantial gradient between T(b) and ambient temperature (T(a)) was sustained even at T(a) = 12 degrees C (T(b) = 30.6 degrees C). Basal metabolic rate of 1.00 mL O2 g(-1) h(-1) at T(a) = 30 degrees C conformed to the general allometric relationship for marsupials, as did wet thermal conductance (5.7 mL O2 g(-1) h(-1) degrees C(-1)). Respiratory rate, tidal volume, and minute volume at thermoneutrality matched metabolic demand such that O2 extraction was 12.4%, and ventilation increased in proportion to metabolic rate at low T(a). Ventilatory accommodation of increased metabolic rate at low T(a) was by an increase in respiratory rate rather than by tidal volume or O2 extraction. Evaporative water loss at the lower limit of thermoneutrality conformed to that of other marsupials. Relative water economy was negative at thermoneutrality but positive below T(a) = 12 degrees C. Interestingly, the Neotropical gracile mouse opossums have a more positive water economy at low T(a) than an Australian arid-zone marsupial, perhaps reflecting seasonal variation in water availability for the mouse opossum. Torpor occurred at low T(a), with spontaneous arousal when T(b) > 20 degrees C. Torpor resulted in absolute energy and water savings but lower relative water economy. We found no evidence that gracile mouse opossums differ physiologically from other marsupials, despite their Neotropical distribution, sympatry with placental mammals, and long period of separation from Australian marsupials.

  17. Metabolic, ventilatory and hygric physiology of the chuditch (Dasyurus geoffroii; Marsupialia, Dasyuridae).

    PubMed

    Schmidt, S; Withers, P C; Cooper, C E

    2009-09-01

    The chuditch is a large carnivorous dasyurid marsupial. Historically it had one of the widest geographical distributions of all marsupials, encompassing much of arid Australia, but it is now restricted to the mesic south-west of Western Australia. It is therefore of interest to determine if its physiology better reflects adaptation to its historically arid or present mesic habitat. The basic physiological parameters of the chuditch conform to other marsupials. Body mass of males (1385 g) was >400% of that predicted by phylogeny and this may be related to its carnivorous diet. Body temperature was 33.9 degrees C at ambient temperatures < or = thermoneutrality, with hyperthermia occurring above thermoneutrality. Basal metabolic rate was 0.361 mL O(2) g(-1) h(-1) at an ambient temperature of 31 degrees C. Metabolic rate increased below the thermoneutral zone by 0.038 mL O(2) g(-1) h(-1) degrees C(-1), and above the thermoneutral zone to 0.444+/-0.059 mL O(2) g(-1) h(-1) at 33.3 degrees C. Standard evaporative water loss was 0.498+/-0.071 mg g(-1) h(-1) at an ambient temperature of 26.0 degrees C, and increased at higher ambient temperatures due to panting and licking. Changes in wet thermal conductance largely reflected changes in evaporative heat loss, and dry thermal conductance increased at high ambient temperature due in part to posture change. Ventilatory parameters were consistent with metabolic demands in and below thermoneutrality, and suggested augmented evaporative heat loss above the thermoneutral zone. Chuditch had a high point of relative water economy of 22.6 degrees C, indicating favourable water economy at even moderate ambient temperatures, due to its low evaporative water loss rather than high metabolic water production. Chuditch were physiologically more similar to marsupials from arid rather than mesic habitats, better reflecting their historical distribution than their current geographical range.

  18. Assessment of ventilatory performance of athletes using the maximal expiratory flow-volume curve.

    PubMed

    Bertholon, J F; Carles, J; Teillac, A

    1986-04-01

    We carried out a maximum expiratory flow-volume curve (MEFV) and a spirometric recording with 67 athletes of different ages (15-27 years) and disciplines (rowers, kayakists, cyclists, swimmers) and with 20 adult and 13 adolescent nonathletic controls of matching ages. These recordings were repeated, with athletes only, after 6-10 months of training. Significant differences between the groups of adult athletes and the controls were observed for some parameters, the most discriminating of which were, in order, the peak expiratory flow (PEF), the forced expiratory volume in the first second (FEV1), and the flow at 75% of the vital capacity (V75). The vital capacity (VC) itself was only higher in the rowers group. The adult athletes, when grouped together (n = 47), produced a higher flow at 50% of their VC (V50) than the control group (+15%, P less than 0.05) with no difference in the flow at 25% of VC (V25) nor in the VC. A study of the effects of training showed no evolution among high level athletes while increases of 14% of the PEF, 5% of the V75, and 7% of the FEV1 were found after 7-10 months of training in adolescents; the VC increased during that time by only 2.7%. The reproducibility of these ventilatory parameters after 6-8 months was studied with adult athletes. The upper limit of the variation (95% CLl) was 12% for the FEV1 and forced vital capacity (FVC), 18% for PEF, 21% for V75 and V50, and 40% for V25.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. Effect of Sildenafil on Ventilatory Efficiency and Exercise Tolerance in Pulmonary Hypertension

    PubMed Central

    Oudiz, Ronald J.; Roveran, Giorgio; Hansen, James E.; Sun, Xing-Guo; Wasserman, Karlman

    2007-01-01

    Background The pulmonary vasculopathy in pulmonary arterial hypertension (PAH) results in increased resistance to pulmonary blood flow, limiting the cardiac output required for the increased O2 demands of exercise. Aims We sought to determine the physiologic basis for clinical improvement in PAH patients receiving sildenafil, hypothesizing that the key mechanisms of improvement are improved blood flow and ventilatory efficiency, leading to improved exercise capacity and O2 pulse over time. Methods We studied 28 PAH patients with (n=14) and without (n=14) sildenafil treatment. All received warfarin and diuretic therapy, and 13/14 sildenafil-treated patients were already receiving specific PAH drugs. Cardiopulmonary exercise testing was performed before and after sildenafil. Results Peak V̇O2, peak O2 pulse, V̇E/V̇CO2 and PetCO2, were 0.84 ± 0.1 L/min, 6.1 ± 0.7 ml • beat−1, 49 ± 2 and 26 ± 1.5 mmHg, and improved after adding sildenafil to 0.91 ± 0.1 L/min, 6.8 ± 0.8 ml • beat−1, 43 ± 2, and 30 ± 1.9, respectively, whereas control patients worsened (p = 0.012, 0.008, 0.008 and 0.0002, treated vs. controls, respectively). Conclusions Sildenafil improves PetCO2, V̇E/V̇CO2, peak O2 pulse and peak V̇O2 during exercise compared to controls. A prospective, placebo-controlled study is needed to validate these findings. PMID:17707133

  20. Patient-ventilator Interaction during Neurally Adjusted Ventilatory Assist in Very Low Birth Weight Infants

    PubMed Central

    Beck, Jennifer; Reilly, Maureen; Grasselli, Giacomo; Mirabella, Lucia; Slutsky, Arthur S.; Dunn, Michael S.; Sinderby, Christer

    2009-01-01

    Neurally Adjusted Ventilatory Assist (NAVA), a mode of mechanical ventilation controlled by diaphragmatic electrical activity (EAdi), may improve patient-ventilator interaction. We examined patient-ventilator interaction by comparing EAdi to ventilator pressure during conventional ventilation and NAVA delivered invasively and non-invasively. Seven intubated infants (birth weight 936g (range 676–1266g); gestational age 26 weeks (range 25–29)) were studied before and after extubation, initially during CV, and then NAVA. NAVA-intubated and NAVA-extubated demonstrated similar delays between onset of EAdi and onset of ventilator pressure of 74± 17 and 72±23 ms (p=0.698), respectively. During CV, the mean trigger delays were not different from NAVA, however 13±8.5% of ventilator breaths were triggered on average 59±27 ms prior to onset of EAdi. There was no difference in off-cycling delays between NAVA-intubated and extubated (32±34 vs. 28±11 ms). CV cycled-off prior to NAVA (120±66 ms prior, p<0.001). During NAVA, EAdi and ventilator pressure were correlated (mean determination coefficient (NAVA-intubated 0.8±0.06 and NAVA-extubated 0.73±0.22)). Pressure delivery during conventional ventilation was not correlated to EAdi. Neural expiratory time was longer (p=0.044), and respiratory rate was lower (p=0.004) during NAVA. We conclude that in low birth weight infants, NAVA can improve patient-ventilator interaction, even in the presence of large leaks. PMID:19218884

  1. Ventilatory and metabolic effects of repeated hypoxia in conscious newborn rabbits.

    PubMed

    Trippenbach, T

    1994-05-01

    To estimate posthypoxia depressing effects on newborns, ventilatory and metabolic effects of repeated hypoxia were studied in 1- to 3-day-old (group 1) and 2-wk-old (group 2) conscious rabbits. In group 1 (n = 18), ventilation was measured by means of a flow plethysmograph. The barometric method was used in group 2 (n = 21). In an additional 19 pups of group 1 and 17 rabbits of group 2, oxygen consumption (VO2) and carbon dioxide production (VCO2) were measured with an open-flow method. In control animals minute ventilation (VE), respiratory rate, tidal volume, VO2, and VCO2 were recorded at 10-min intervals for approximately 100 min in room air. All variables did not change with time. Separate sets of newborns were exposed five times for 10 min to 10% O2 in N2. Each exposure was followed by 10 min of recovery in room air. VE measured during recoveries after hypoxia always returned to normal in group 1. In group 2, the normoxic VE during the last recovery was greater than the first value in hypoxia-treated rabbits (P < 0.05) and greater than the last value in control rabbits (P < 0.02). Although the VE response to hypoxia was not affected by repetitive exposures in group 2, at minute 5 of the fifth exposure the VE response was greater than that during the first trial in group 1 (P < 0.02). Repetitive exposures had no effects on metabolic response to hypoxia in all pups. Results of this study indicate that hypoxia-related central inhibition, if developed during the exposures, is reversed by 10 min of breathing room air in newborns.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8203635

  2. Pressure support. Changes in ventilatory pattern and components of the work of breathing.

    PubMed

    Van de Graaff, W B; Gordey, K; Dornseif, S E; Dries, D J; Kleinman, B S; Kumar, P; Mathru, M

    1991-10-01

    To evaluate the interaction between patient and ventilator during widely varying levels of pressure support (PS) ventilation, we studied 33 patients who had undergone aortocoronary bypass. All patients were without preoperative evidence of lung disease and had left ventricular ejection fractions greater than 45 percent. We assessed both changes in ventilatory pattern and the use of an extension of the Campbell technique to determine the components of the mechanical work of breathing (WOB). Patients were placed on 0, 10, 20, and 30 cm H2O of PS. We found that increasing the pressure support level (PSL) did not change minute ventilation, PCO2, or pH despite large changes in both rate and depth of breathing. The inspiratory time fraction was consistently and progressively reduced as PS increased. Although mean inspiratory flow (MIF) increased by 75 +/- 9 (SE) percent as the PSL increased to 30 cm H2O, mean airway pressure rose only 3.5 +/- 0.1 cm H2O. Observed changes in the resistive and elastic components of WOB at PSL greater than 0 were consistent with values predicted from baseline observations and changes in VT and MIF demonstrating that the Campbell technique of separating resistive and elastic components of the patient's WOB during unassisted ventilation can be extended to the analysis of WOB during mechanical ventilation. We were surprised to observe that although inspiratory WOB fell 67 +/- 13 percent as the PSL increased to 30 cm H2O, postinspiratory work by the inspiratory muscles (WOBPIIM) did not show significant change. The persistence and substantial values of WOBPIIM in some patients suggested the presence of significant patient-ventilator dyssynchrony, especially at higher levels of PS. Total inspiratory WOB per minute, including both patient WOB and WOB by the ventilator, increased by 186 +/- 29 percent, demonstrating that PS results in a respiratory pattern requiring substantially greater total mechanical work.

  3. Ventilatory mechanics and the effects of water depth on breathing pattern in the aquatic caecilian Typhlonectes natans.

    PubMed

    Prabha, K C; Bernard, D G; Gardner, M; Smatresk, N J

    2000-01-01

    The breathing pattern in the aquatic caecilian Typhlonectes natans was investigated by recording airflow via a pneumotachograph under unrestrained normal physiological conditions. Ventilatory mechanics were assessed using airflow and pressure measurements from the buccal cavity and trachea. The breathing pattern consisted of an expiratory phase followed by a series of 10-15 small buccal pumps to inflate the lung, succeeded by a long non-ventilatory period. T. natans separate the expiratory and inspiratory gases in the buccal cavity and take several inspiratory pumps, distinguishing their breathing pattern from that of sarcopterygians. Hydrostatic pressure assisted exhalation. The tracheal pressure was greater than the water pressure at that depth, suggesting that pleuroperitoneal pressure as well as axial or pulmonary smooth muscles may have contributed to the process of exhalation. The frequency of lung ventilation was 6.33+/-0.84 breaths h(-)(1), and ventilation occurred via the nares. Compared with other amphibians, this low ventilatory frequency suggests that T. natans may have acquired very efficient pulmonary respiration as an adaptation for survival in their seasonally fluctuating natural habitat. Their respiratory pathway is quite unique, with the trachea separated into anterior, central and posterior regions. The anterior region serves as an air channel, the central region is attached to the tracheal lung, and the posterior region consists of a bifurcated air channel leading to the left and right posterior lungs. The lungs are narrow, elongated, profusely vascularized and compartmentalized. The posterior lungs extend to approximately two-thirds of the body length. On the basis of their breathing pattern, it appears that caecilians are phylogenetically derived from two-stroke breathers.

  4. Ventilatory function in workers exposed to low levels of toluene diisocyanate: a six-month follow-up

    PubMed Central

    Peters, John M.; Murphy, Raymond L. H.; Ferris, Benjamin G.

    1969-01-01

    Peters, John M., Murphy, Raymond L. H., and Ferris, Benjamin, G., Jr. (1969).Brit. J. industr. Med.,26, 115-120. Ventilatory function in workers exposed to low levels of toluene diisocyanate: a six-month follow-up. Thirty-four workers exposed to toluene diisocyanate during production of polyurethane foam were examined with a respiratory questionnaire and tests of ventilatory capacity. The tests of pulmonary function were conducted on Monday morning and afternoon and on Tuesday morning and afternoon. Twenty-eight of these 34 workers had been examined with the same tests six months earlier. On Monday a mean change in the one-second forced expiratory volume (F.E.V.1·0) of –0·16 l. occurred that did not return to the baseline value (Monday a.m.) on Tuesday morning. A statistically significant decrease in all the measurements of ventilatory capacity except the forced vital capacity occurred over the six months in the 28 workers. The F.E.V.1·0 fell an average of 0·14 l. and flow rates at 75%, 50%, 25%, and 10% of vital capacity also decreased significantly. There was a highly significant correlation coefficient (r = 0·72) between one-day changes in F.E.V.1·0 (measured six months earlier) and six-month changes in F.E.V.1·0. Workers with respiratory symptoms (cough and/or phlegm) demonstrated greater falls in F.E.V.1·0 than did asymptomatic workers. All air concentrations of toluene diisocyanate measured during this study were below the threshold limit value (0·02 p.p.m.). PMID:5780102

  5. Ventilatory mechanics and the effects of water depth on breathing pattern in the aquatic caecilian Typhlonectes natans.

    PubMed

    Prabha, K C; Bernard, D G; Gardner, M; Smatresk, N J

    2000-01-01

    The breathing pattern in the aquatic caecilian Typhlonectes natans was investigated by recording airflow via a pneumotachograph under unrestrained normal physiological conditions. Ventilatory mechanics were assessed using airflow and pressure measurements from the buccal cavity and trachea. The breathing pattern consisted of an expiratory phase followed by a series of 10-15 small buccal pumps to inflate the lung, succeeded by a long non-ventilatory period. T. natans separate the expiratory and inspiratory gases in the buccal cavity and take several inspiratory pumps, distinguishing their breathing pattern from that of sarcopterygians. Hydrostatic pressure assisted exhalation. The tracheal pressure was greater than the water pressure at that depth, suggesting that pleuroperitoneal pressure as well as axial or pulmonary smooth muscles may have contributed to the process of exhalation. The frequency of lung ventilation was 6.33+/-0.84 breaths h(-)(1), and ventilation occurred via the nares. Compared with other amphibians, this low ventilatory frequency suggests that T. natans may have acquired very efficient pulmonary respiration as an adaptation for survival in their seasonally fluctuating natural habitat. Their respiratory pathway is quite unique, with the trachea separated into anterior, central and posterior regions. The anterior region serves as an air channel, the central region is attached to the tracheal lung, and the posterior region consists of a bifurcated air channel leading to the left and right posterior lungs. The lungs are narrow, elongated, profusely vascularized and compartmentalized. The posterior lungs extend to approximately two-thirds of the body length. On the basis of their breathing pattern, it appears that caecilians are phylogenetically derived from two-stroke breathers. PMID:10607536

  6. Immunoadjuvant Therapy and Noninvasive Ventilation for Acute Respiratory Failure in Lung Tuberculosis: A Case Study

    PubMed Central

    Flores-Franco, René Agustín; Olivas-Medina, Dahyr Alberto; Pacheco-Tena, Cesar Francisco; Duque-Rodríguez, Jorge

    2015-01-01

    Acute respiratory failure caused by pulmonary tuberculosis is a rare event but with a high mortality even while receiving mechanical ventilatory support. We report the case of a young man with severe pulmonary tuberculosis refractory to conventional therapy who successfully overcame the critical period of his condition using noninvasive ventilation and immunoadjuvant therapy that included three doses of etanercept 25 mg subcutaneously. We conclude that the use of etanercept along with antituberculosis treatment appears to be safe and effective in patients with pulmonary tuberculosis presenting with acute respiratory failure. PMID:26273486

  7. Assessment of ventilatory thresholds during graded and maximal exercise test using time varying analysis of respiratory sinus arrhythmia

    PubMed Central

    Blain, G; Meste, O; Bouchard, T; Bermon, S; Segura, R.

    2005-01-01

    Objective: To test whether ventilatory thresholds, measured during an exercise test, could be assessed using time varying analysis of respiratory sinus arrhythmia frequency (fRSA). Methods: Fourteen sedentary subjects and 12 endurance athletes performed a graded and maximal exercise test on a cycle ergometer: initial load 75 W (sedentary subjects) and 150 W (athletes), increments 37.5 W/2 min. fRSA was extracted from heart period series using an evolutive model. First (TV1) and second (TV2) ventilatory thresholds were determined from the time course curves of ventilation and ventilatory equivalents for O2 and CO2. Results: fRSA was accurately extracted from all recordings and positively correlated to respiratory frequency (r = 0.96 (0.03), p<0.01). In 21 of the 26 subjects, two successive non-linear increases were determined in fRSA, defining the first (TRSA1) and second (TRSA2) fRSA thresholds. When expressed as a function of power, TRSA1 and TRSA2 were not significantly different from and closely linked to TV1 (r = 0.99, p<0.001) and TV2 (r = 0.99, p<0.001), respectively. In the five remaining subjects, only one non-linear increase was observed close to TV2. Significant differences (p<0.04) were found between athlete and sedentary groups when TRSA1 and TRSA2 were expressed in terms of absolute and relative power and percentage of maximal aerobic power. In the sedentary group, TRSA1 and TRSA2 were 150.3 (18.7) W and 198.3 (28.8) W, respectively, whereas in the athlete group TRSA1 and TRSA2 were 247.3 (32.8) W and 316.0 (28.8) W, respectively. Conclusions: Dynamic analysis of fRSA provides a useful tool for identifying ventilatory thresholds during graded and maximal exercise test in sedentary subjects and athletes. PMID:15976169

  8. Acute Bronchitis

    MedlinePlus

    ... tightness. There are two main types of bronchitis: acute and chronic. Most cases of acute bronchitis get better within several days. But your ... that cause colds and the flu often cause acute bronchitis. These viruses spread through the air when ...

  9. [Pumpless extracorporeal pulmonary care: an alternative in the treatment of persistent acute respiratory distress syndrome].

    PubMed

    Tomicic, V; Montalván, C; Espinoza, M; Graf, J; Martínez, E; Umaña, A; Torres, J

    2008-01-01

    A 34-year old woman who developed persistent and severe acute respiratory distress syndrome with underlying myelomonocytic leukemia (M4FAB) is described. After ruling out the most common causes of pulmonary infiltration in this type of patient and one week of broad spectrum antibiotics and steroids therapy, we proposed leukemic pulmonary infiltration as etiological diagnosis. Despite using a protective ventilatory strategy, recruitment maneuvers, prone position and high frequency oscillatory ventilation, her gas exchange became worse. Under this condition we used a Pumpless-Extracorporeal life assist (PELA) and begun chemotherapy. The method, arterial blood gases, hemodynamic parameters and ventilatory mechanics before and after its use are described. The patient remained on P-ELA for nine days; one week later she was extubated and ten days after she was discharged from the Intensive Care Unit the patient left the hospital in good health condition.

  10. A Simplified Approach for Estimating the Ventilatory and Respiratory Compensation Thresholds

    PubMed Central

    Condello, Giancarlo; Reynolds, Ezekiel; Foster, Carl; de Koning, Jos J.; Casolino, Erika; Knutson, Megan; Porcari, John P.

    2014-01-01

    This study aimed to investigate whether ventilatory (VT) and respiratory compensation (RCT) thresholds could be derived from percentages of maximal running speed (Vmax). During the model building phase (1), VT & RCT of 31 competitive level athletes were identified with respiratory gas exchange. During the cross-validation phase (2), 20 subjects performed a treadmill test to identify Vmax and then they performed 30-min runs at velocities 2SE below or above the velocity at VT and RCT derived from (1), with measurement of blood lactate [BL], RPE, heart rate (HR), and speech comfort. Phase (1) revealed that VT and RCT were reached at 67 ± 9% and 84 ± 6% of Vmax. In (2) sustained running 2SE below VT (64% Vmax) was associated with the ability to finish 30-min, with low and constant [BL] (~2.5 mmol.l-1), moderate RPE (~3.0-3.5), a small HR drift, and ability to speak comfortably. Conversely, running at 2SE above RCT (86% Vmax) was associated with the inability to finish 30-min (18.5 ± 2.5 min to fatigue), increasing [BL] (end-exercise = 11.9 ± 0.9 mmol.l-1), high RPE (end-exercise = 8.9 ± 1.0), large HR drift (end-exercise = 98 ± 3% HRmax), and inability to speak comfortably. Simple percentages of Vmax (≤64% and ≥86%) obtained from a treadmill test without gas exchange, may be useful for prescribing exercise training intensities. Key points Simple performance parameters can be used to provide indications of physiologic thresholds. 64% and 86% of the maximal running speed produce conditions consistent with ≤VT and ≥RCT. The combination of technology free feedback techniques such as the Talk Test and RPE and the simple %Vmax can be used as available and easy methods for the performance evaluation. Training prescription can be better addressed to the improvement of the aerobic or anaerobic capacity. PMID:24790484

  11. A simplified approach for estimating the ventilatory and respiratory compensation thresholds.

    PubMed

    Condello, Giancarlo; Reynolds, Ezekiel; Foster, Carl; de Koning, Jos J; Casolino, Erika; Knutson, Megan; Porcari, John P

    2014-05-01

    This study aimed to investigate whether ventilatory (VT) and respiratory compensation (RCT) thresholds could be derived from percentages of maximal running speed (Vmax). During the model building phase (1), VT & RCT of 31 competitive level athletes were identified with respiratory gas exchange. During the cross-validation phase (2), 20 subjects performed a treadmill test to identify Vmax and then they performed 30-min runs at velocities 2SE below or above the velocity at VT and RCT derived from (1), with measurement of blood lactate [BL], RPE, heart rate (HR), and speech comfort. Phase (1) revealed that VT and RCT were reached at 67 ± 9% and 84 ± 6% of Vmax. In (2) sustained running 2SE below VT (64% Vmax) was associated with the ability to finish 30-min, with low and constant [BL] (~2.5 mmol.l(-1)), moderate RPE (~3.0-3.5), a small HR drift, and ability to speak comfortably. Conversely, running at 2SE above RCT (86% Vmax) was associated with the inability to finish 30-min (18.5 ± 2.5 min to fatigue), increasing [BL] (end-exercise = 11.9 ± 0.9 mmol.l(-1)), high RPE (end-exercise = 8.9 ± 1.0), large HR drift (end-exercise = 98 ± 3% HRmax), and inability to speak comfortably. Simple percentages of Vmax (≤64% and ≥86%) obtained from a treadmill test without gas exchange, may be useful for prescribing exercise training intensities. Key pointsSimple performance parameters can be used to provide indications of physiologic thresholds.64% and 86% of the maximal running speed produce conditions consistent with ≤VT and ≥RCT.The combination of technology free feedback techniques such as the Talk Test and RPE and the simple %Vmax can be used as available and easy methods for the performance evaluation.Training prescription can be better addressed to the improvement of the aerobic or anaerobic capacity. PMID:24790484

  12. Respiratory symptoms and ventilatory functions among quarry workers in Edo state, Nigeria

    PubMed Central

    Isara, Alphonsus Rukevwe; Adam, Vincent Yakubu; Aigbokhaode, Adesuwa Queen; Alenoghena, Innocent Osi

    2016-01-01

    Introduction Workers in the quarry industries are exposed to hazards resulting from the inhalation of air borne particulates. The study determined the prevalence of respiratory symptoms and assessed ventilatory functions among quarry workers in Edo state, Nigeria. Methods Quarry workers (site workers and office workers) were interviewed using structured questionnaire. FEV1, FVC, FEV1/FVC and PEFR were measured using a KoKo Legend spirometer. Results A total of 113 quarry workers (76 exposure and 37 controls) were studied. The exposure group had significantly higher occurrence of chest tightness (35.5%) compared with 16.2% of the controls (p < 0.05). The occurrence of cough (23.7% versus 13.5%), sputum (21.1% versus 16.2%), and dyspnoea (7.9% versus 5.4%), were higher in exposure groups while wheeze (10.8% versus 10.5%) and nasal congestion (27.0% and 25.0%) were higher in the control groups. The mean (SD) FEV1, and FVC were significantly lower among the exposure compared with the control group; 2.77L (0.73) versus 3.14L (0.78), p < 0.05, and 3.48L (0.84) versus 3.89L (0.92), p < 0.05. In both groups, smokers had significantly lower mean (SD) FEV1, FVC and PEFR compared with non-smokers; 2.91L (0.77) versus 3.39L (0.69), p = 0.01, 3.61L (0.91) versus 4.26L (0.74), p < 0.05 and 6.56L (2.43) versus 7.98L (1.67), p < 0.05. Conclusion Chronic exposure to quarry dust is associated with respiratory symptoms and reduced lung function indices among quarry workers. The enforcement of the use of PPEs and periodic evaluation the lung function status of quarry workers is advocated. PMID:27347301

  13. The Effects of a Duathlon Simulation on Ventilatory Threshold and Running Economy

    PubMed Central

    Berry, Nathaniel T.; Wideman, Laurie; Shields, Edgar W.; Battaglini, Claudio L.

    2016-01-01

    Multisport events continue to grow in popularity among recreational, amateur, and professional athletes around the world. This study aimed to determine the compounding effects of the initial run and cycling legs of an International Triathlon Union (ITU) Duathlon simulation on maximal oxygen uptake (VO2max), ventilatory threshold (VT) and running economy (RE) within a thermoneutral, laboratory controlled setting. Seven highly trained multisport athletes completed three trials; Trial-1 consisted of a speed only VO2max treadmill protocol (SOVO2max) to determine VO2max, VT, and RE during a single-bout run; Trial-2 consisted of a 10 km run at 98% of VT followed by an incremental VO2max test on the cycle ergometer; Trial-3 consisted of a 10 km run and 30 km cycling bout at 98% of VT followed by a speed only treadmill test to determine the compounding effects of the initial legs of a duathlon on VO2max, VT, and RE. A repeated measures ANOVA was performed to determine differences between variables across trials. No difference in VO2max, VT (%VO2max), maximal HR, or maximal RPE was observed across trials. Oxygen consumption at VT was significantly lower during Trial-3 compared to Trial-1 (p = 0.01). This decrease was coupled with a significant reduction in running speed at VT (p = 0.015). A significant interaction between trial and running speed indicate that RE was significantly altered during Trial-3 compared to Trial-1 (p < 0.001). The first two legs of a laboratory based duathlon simulation negatively impact VT and RE. Our findings may provide a useful method to evaluate multisport athletes since a single-bout incremental treadmill test fails to reveal important alterations in physiological thresholds. Key points Decrease in relative oxygen uptake at VT (ml·kg-1·min-1) during the final leg of a duathlon simulation, compared to a single-bout maximal run. We observed a decrease in running speed at VT during the final leg of a duathlon simulation; resulting in an

  14. The Effects of a Duathlon Simulation on Ventilatory Threshold and Running Economy.

    PubMed

    Berry, Nathaniel T; Wideman, Laurie; Shields, Edgar W; Battaglini, Claudio L

    2016-06-01

    Multisport events continue to grow in popularity among recreational, amateur, and professional athletes around the world. This study aimed to determine the compounding effects of the initial run and cycling legs of an International Triathlon Union (ITU) Duathlon simulation on maximal oxygen uptake (VO2max), ventilatory threshold (VT) and running economy (RE) within a thermoneutral, laboratory controlled setting. Seven highly trained multisport athletes completed three trials; Trial-1 consisted of a speed only VO2max treadmill protocol (SOVO2max) to determine VO2max, VT, and RE during a single-bout run; Trial-2 consisted of a 10 km run at 98% of VT followed by an incremental VO2max test on the cycle ergometer; Trial-3 consisted of a 10 km run and 30 km cycling bout at 98% of VT followed by a speed only treadmill test to determine the compounding effects of the initial legs of a duathlon on VO2max, VT, and RE. A repeated measures ANOVA was performed to determine differences between variables across trials. No difference in VO2max, VT (%VO2max), maximal HR, or maximal RPE was observed across trials. Oxygen consumption at VT was significantly lower during Trial-3 compared to Trial-1 (p = 0.01). This decrease was coupled with a significant reduction in running speed at VT (p = 0.015). A significant interaction between trial and running speed indicate that RE was significantly altered during Trial-3 compared to Trial-1 (p < 0.001). The first two legs of a laboratory based duathlon simulation negatively impact VT and RE. Our findings may provide a useful method to evaluate multisport athletes since a single-bout incremental treadmill test fails to reveal important alterations in physiological thresholds. Key pointsDecrease in relative oxygen uptake at VT (ml·kg(-1)·min(-1)) during the final leg of a duathlon simulation, compared to a single-bout maximal run.We observed a decrease in running speed at VT during the final leg of a duathlon simulation; resulting in an

  15. Performance of heated humidifiers with a heated wire according to ventilatory settings.

    PubMed

    Nishida, T; Nishimura, M; Fujino, Y; Mashimo, T

    2001-01-01

    Delivering warm, humidified gas to patients is important during mechanical ventilation. Heated humidifiers are effective and popular. The humidifying efficiency is influenced not only by performance and settings of the devices but the settings of ventilator. We compared the efficiency of humidifying devices with a heated wire and servo-controlled function under a variety of ventilator settings. A bench study was done with a TTL model lung. The study took place in the laboratory of the University Hospital, Osaka, Japan. Four devices (MR290 with MR730, MR310 with MR730; both Fisher & Paykel, ConchaTherm IV; Hudson RCI, and HummaxII; METRAN) were tested. Hummax II has been developed recently, and it consists of a heated wire and polyethylene microporous hollow fiber. Both wire and fiber were put inside of an inspiratory circuit, and water vapor is delivered throughout the circuit. The Servo 300 was connected to the TTL with a standard ventilator circuit. The ventilator settings were as follows; minute ventilation (V(E)) 5, 10, and 15 L/min, a respiratory rate of 10 breaths/min, I:E ratio 1:1, 1:2, and 1:4, and no applied PEEP. Humidifying devices were set to maintain the temperature of airway opening at 32 degrees C and 37 degrees C. The greater V(E) the lower the humidity with all devices except Hummax II. Hummax II delivered 100% relative humidity at all ventilator and humidifier settings. When airway temperature control of the devices was set at 32 degrees C, the ConchaTherm IV did not deliver 30 mg/L of vapor, which is the value recommended by American National Standards at all V(E) settings. At 10 and 15 L/min of V(E) settings MR310 with MR730 did not deliver recommended vapor, either. In conclusion, airway temperature setting of the humidifying devices influenced the humidity of inspiratory gas greatly. Ventilatory settings also influenced the humidity of inspiratory gas. The Hummax II delivered sufficient water vapor under a variety of minute ventilation.

  16. The Effects of a Duathlon Simulation on Ventilatory Threshold and Running Economy.

    PubMed

    Berry, Nathaniel T; Wideman, Laurie; Shields, Edgar W; Battaglini, Claudio L

    2016-06-01

    Multisport events continue to grow in popularity among recreational, amateur, and professional athletes around the world. This study aimed to determine the compounding effects of the initial run and cycling legs of an International Triathlon Union (ITU) Duathlon simulation on maximal oxygen uptake (VO2max), ventilatory threshold (VT) and running economy (RE) within a thermoneutral, laboratory controlled setting. Seven highly trained multisport athletes completed three trials; Trial-1 consisted of a speed only VO2max treadmill protocol (SOVO2max) to determine VO2max, VT, and RE during a single-bout run; Trial-2 consisted of a 10 km run at 98% of VT followed by an incremental VO2max test on the cycle ergometer; Trial-3 consisted of a 10 km run and 30 km cycling bout at 98% of VT followed by a speed only treadmill test to determine the compounding effects of the initial legs of a duathlon on VO2max, VT, and RE. A repeated measures ANOVA was performed to determine differences between variables across trials. No difference in VO2max, VT (%VO2max), maximal HR, or maximal RPE was observed across trials. Oxygen consumption at VT was significantly lower during Trial-3 compared to Trial-1 (p = 0.01). This decrease was coupled with a significant reduction in running speed at VT (p = 0.015). A significant interaction between trial and running speed indicate that RE was significantly altered during Trial-3 compared to Trial-1 (p < 0.001). The first two legs of a laboratory based duathlon simulation negatively impact VT and RE. Our findings may provide a useful method to evaluate multisport athletes since a single-bout incremental treadmill test fails to reveal important alterations in physiological thresholds. Key pointsDecrease in relative oxygen uptake at VT (ml·kg(-1)·min(-1)) during the final leg of a duathlon simulation, compared to a single-bout maximal run.We observed a decrease in running speed at VT during the final leg of a duathlon simulation; resulting in an

  17. Ventilation and hypoxic ventilatory response of Tibetan and Aymara high altitude natives.

    PubMed

    Beall, C M; Strohl, K P; Blangero, J; Williams-Blangero, S; Almasy, L A; Decker, M J; Worthman, C M; Goldstein, M C; Vargas, E; Villena, M; Soria, R; Alarcon, A M; Gonzales, C

    1997-12-01

    Newcomers acclimatizing to high altitude and adult male Tibetan high altitude natives have increased ventilation relative to sea level natives at sea level. However, Andean and Rocky Mountain high altitude natives have an intermediate level of ventilation lower than that of newcomers and Tibetan high altitude natives although generally higher than that of sea level natives at sea level. Because the reason for the relative hypoventilation of some high altitude native populations was unknown, a study was designed to describe ventilation from adolescence through old age in samples of Tibetan and Andean high altitude natives and to estimate the relative genetic and environmental influences. This paper compares resting ventilation and hypoxic ventilatory response (HVR) of 320 Tibetans 9-82 years of age and 542 Bolivian Aymara 13-94 years of age, native residents at 3,800-4,065 m. Tibetan resting ventilation was roughly 1.5 times higher and Tibetan HVR was roughly double that of Aymara. Greater duration of hypoxia (older age) was not an important source of variation in resting ventilation or HVR in either sample. That is, contrary to previous studies, neither sample acquired hypoventilation in the age ranges under study. Within populations, greater severity of hypoxia (lower percent of oxygen saturation of arterial hemoglobin) was associated with slightly higher resting ventilation among Tibetans and lower resting ventilation and HVR among Aymara women, although the associations accounted for just 2-7% of the variation. Between populations, the Tibetan sample was more hypoxic and had higher resting ventilation and HVR. Other systematic environmental contrasts did not appear to elevate Tibetan or depress Aymara ventilation. There was more intrapopulation genetic variation in these traits in the Tibetan than the Aymara sample. Thirty-five percent of the Tibetan, but none of the Aymara, resting ventilation variance was due to genetic differences among individuals. Thirty

  18. Effects of hypercapnia and inspiratory flow-resistive loading on respiratory activity in chronic airways obstruction.

    PubMed Central

    Altose, M D; McCauley, W C; Kelsen, S G; Cherniack, N S

    1977-01-01

    The respiratory responses to hypercapnia alone and to hypercapnia and flow-resistive loading during inspiration were studied in normal individuals and in eucapnic and hypercapnic patients with chronic airways obstruction. Responses were assessed in terms of minute ventilation and occlusion pressure (mouth pressure during airway occlusion 100 ms after the onset of inspiration). Ventilatory responses to CO2 (deltaV/deltaPCO2) were distinctly subnormal in both groups of patients with airways obstruction. The two groups of patients, however, showed different occlusion pressure responses to CO2 (deltaP100/deltaPCO2): deltaP100/deltaPCO2 was normal in the eucapnic patients but subnormal in the hypercapnic patients. Flow-resistive loading during inspiration reduced deltaV/deltaPCO2 both in normal subjects and in patients with airways obstruction. The occlusion pressure response to CO2 increased in normal subjects during flow-resistive loading but remained unchanged in both groups of patients with chronic airways obstruction. These results indicate that while chemosensitivity as determined by deltaP100/deltaPCO2 is impaired only in hypercapnic patients with chronic airways obstruction, an acute increase in flow resistance elicits a subnormal increase in respiratory efferent activity in both eucapnic and hypercapnic patients. PMID:838862

  19. Chest radiographs fail to detect right ventricular enlargement and right atrial enlargement in patients with a pure restrictive ventilatory impairment.

    PubMed

    Shivkumar, K; Ravi, K; Henry, J W; Eichenhorn, M S; Stein, P D

    1994-08-01

    The validity of measurements of the cardiac silhouette on chest radiographs for the evaluation of right ventricular enlargement and right atrial enlargement in patients with a pure restrictive ventilatory impairment was investigated in 19 patients. The forced vital capacity (FVC) percent predicted in these patients was 59 +/- 12 percent (mean +/- SD) (range, 29 to 79 percent). Right ventricular enlargement, by two-dimensional echocardiography, was defined as a right ventricular area > 20.4 cm2 and right atrial enlargement was defined as a right atrial area > 15.3 cm2. Chest radiographic measurements in the posteroanterior (PA) projection included distance from the midline to the farthest point of the right border of the cardiac silhouette, transverse cardiac diameter, and cardiothoracic ratio. Measurements in the lateral projection included the lateral horizontal transverse diameter, ventral portion of the lateral broad diameter, and obliteration of the retrosternal space. Neither the right ventricular area nor the right atrial area correlated with any of these radiographic measurements. There were no differences in these chest radiographic measurements among patients with normal right ventricular and right atrial dimensions, patients with right ventricular enlargement, and patients with right atrial enlargement. We conclude, therefore, that PA and lateral chest radiographs do not reliably detect right ventricular enlargement or right atrial enlargement in patients with a pure restrictive ventilatory impairment.

  20. Effect of jute dust exposure on ventilatory function and the pertinence of cough and smoking to the response.

    PubMed

    Chattopadhyay, B P; Alams, J; Gangopadhyay, P K; Saiyed, H N

    1995-06-01

    The ventilatory capacity of 32 men exposed to jute dust in the jute industry, was estimated at the beginning and end of shifts on the first day and last day of a working week. A detailed occupational, clinical and smoking history was recorded and a more detailed questionnaire on respiratory symptoms was completed prior to the pulmonary function tests. The presence of a productive cough among workers was noted. A mean decrease of forced expiratory volume at one second (FEV1) was observed among workers according to processes, concentration of dust exposure and smoking habit on the first day and last day of the week. The mean difference of values was observed in most of the comparisons but only a few were statistically significant. Low mean values of FEV1 were observed in workers having high dust exposure, a smoking history and productive cough in comparison to the low dust exposure group, non-smokers and workers without cough symptoms. The significant deterioration of FEV1 was found between before shift and after shift values of the low dust exposed group of workers who had a cough and smoking history. The relevance of these factors on the ventilatory function is observed and discussed.

  1. Effects of beta-alanine supplementation on the onset of neuromuscular fatigue and ventilatory threshold in women.

    PubMed

    Stout, J R; Cramer, J T; Zoeller, R F; Torok, D; Costa, P; Hoffman, J R; Harris, R C; O'Kroy, J

    2007-01-01

    This study examined the effects of 28 days of beta-alanine supplementation on the physical working capacity at fatigue threshold (PWCFT), ventilatory threshold (VT), maximal oxygen consumption (VO2-MAX), and time-to-exhaustion (TTE) in women. Twenty-two women (age+/-SD 27.4+/-6.1 yrs) participated and were randomly assigned to either the beta-alanine (CarnoSyn) or Placebo (PL) group. Before (pre) and after (post) the supplementation period, participants performed a continuous, incremental cycle ergometry test to exhaustion to determine the PWCFT, VT, VO2-MAX, and TTE. There was a 13.9, 12.6 and 2.5% increase (p<0.05) in VT, PWCFT, and TTE, respectively, for the beta-alanine group, with no changes in the PL (p>0.05). There were no changes for VO2-MAX (p>0.05) in either group. Results of this study indicate that beta-alanine supplementation delays the onset of neuromuscular fatigue (PWCFT) and the ventilatory threshold (VT) at submaximal workloads, and increase in TTE during maximal cycle ergometry performance. However, beta-alanine supplementation did not affect maximal aerobic power (VO2-MAX). In conclusion, beta-alanine supplementation appears to improve submaximal cycle ergometry performance and TTE in young women, perhaps as a result of an increased buffering capacity due to elevated muscle carnosine concentrations.

  2. Mechanical ventilation with heated humidifiers: measurements of condensed water mass within the breathing circuit according to ventilatory settings.

    PubMed

    Schena, E; Saccomandi, P; Cappelli, S; Silvestri, S

    2013-07-01

    Heated wire humidifiers (HWHs) are widely used to heat and humidify gases during mechanical ventilation. The control strategy implemented on commercial HWHs, based on maintaining constant gas temperature at the chamber outlet, shows weaknesses: humidifying performances depend on environmental temperature and ventilatory settings, and often condensation occurs. Herein, we analyzed in vitro HWH performances focusing on the condensation amount according to ventilatory settings. We used a physical model to define the parameters which mainly influence the HWH performances. In order to investigate the influence of minute volume (MV) and frequency rate (fr) on condensation, the other influencing parameters were kept constant during experiments, and we introduced a novel approach to estimate the condensation. The method, based on measuring the condensed vapor mass (Δm), provided more objective information than the visual-based scale used in previous studies. Thanks to both the control of other influencing factors and the accurate Δm measures, the investigation showed the Δm increase with MV and fr. Substantial condensation after 7 h of ventilation and the influence of MV and fr on Δm (i.e., Δm = 3 g at MV = 1.5 L min(-1) and fr = 8 bpm and Δm = 9.4 g at MV = 8 L min(-1) and fr = 20 bpm) confirm the weaknesses of `single-point temperature' control strategies.

  3. Oxygenation Threshold Derived from Near-Infrared Spectroscopy: Reliability and Its Relationship with the First Ventilatory Threshold

    PubMed Central

    Jaspers, Richard T.; Blokland, Ilse J.; Achterberg, Chantal; Visser, Jurrian M.; den Uil, Anne R.; Hofmijster, Mathijs J.; Levels, Koen; Noordhof, Dionne A.; de Haan, Arnold; de Koning, Jos J.; van der Laarse, Willem J.; de Ruiter, Cornelis J.

    2016-01-01

    Background Near-infrared spectroscopy (NIRS) measurements of oxygenation reflect O2 delivery and utilization in exercising muscle and may improve detection of a critical exercise threshold. Purpose First, to detect an oxygenation breakpoint (Δ[O2HbMb-HHbMb]-BP) and compare this breakpoint to ventilatory thresholds during a maximal incremental test across sexes and training status. Second, to assess reproducibility of NIRS signals and exercise thresholds and investigate confounding effects of adipose tissue thickness on NIRS measurements. Methods Forty subjects (10 trained male cyclists, 10 trained female cyclists, 11 endurance trained males and 9 recreationally trained males) performed maximal incremental cycling exercise to determine Δ[O2HbMb-HHbMb]-BP and ventilatory thresholds (VT1 and VT2). Muscle haemoglobin and myoglobin O2 oxygenation ([HHbMb], [O2HbMb], SmO2) was determined in m. vastus lateralis. Δ[O2HbMb-HHbMb]-BP was determined by double linear regression. Trained cyclists performed the maximal incremental test twice to assess reproducibility. Adipose tissue thickness (ATT) was determined by skinfold measurements. Results Δ[O2HbMb-HHbMb]-BP was not different from VT1, but only moderately related (r = 0.58–0.63, p<0.001). VT1 was different across sexes and training status, whereas Δ[O2HbMb-HHbMb]-BP differed only across sexes. Reproducibility was high for SmO2 (ICC = 0.69–0.97), Δ[O2HbMb-HHbMb]-BP (ICC = 0.80–0.88) and ventilatory thresholds (ICC = 0.96–0.99). SmO2 at peak exercise and at occlusion were strongly related to adipose tissue thickness (r2 = 0.81, p<0.001; r2 = 0.79, p<0.001). Moreover, ATT was related to asymmetric changes in Δ[HHbMb] and Δ[O2HbMb] during incremental exercise (r = -0.64, p<0.001) and during occlusion (r = -0.50, p<0.05). Conclusion Although the oxygenation threshold is reproducible and potentially a suitable exercise threshold, VT1 discriminates better across sexes and training status during maximal stepwise

  4. Protection of the blood-brain barrier by hypercapnia during acute hypertension

    SciTech Connect

    Baumbach, G.L.; Mayhan, W.G.; Heistad, D.D.

    1986-08-01

    The purpose of this study was to examine effects of hypercapnia on susceptibility of the blood-brain barrier to disruption during acute hypertension. Two methods were used to test the hypothesis that cerebral vasodilation during hypercapnia increases disruption of the blood-brain barrier. First, permeability of the blood-brain barrier was measured in anesthetized cats with SVI-labeled serum albumin. Severe hypertension markedly increased permeability of the blood-brain barrier during normocapnia, but not during hypercapnia. The protective effect of hypercapnia was not dependent on sympathetic nerves. Second, in anesthetized rats, permeability of the barrier was quantitated by clearance of fluorescent dextran. Disruption of the blood-brain barrier during hypertension was decreased by hypercapnia. Because disruption of the blood-brain barrier occurred primarily in pial venules, the authors also measured pial venular diameter and pressure. Acute hypertension increased pial venular pressure and diameter in normocapnic rats. Hypercapnia alone increased pial venular pressure and pial venular diameter, and acute hypertension during hypercapnia further increased venular pressure. The magnitude of increase in pial venular pressure during acute hypertension was significantly less in hypercapnic than in normocapnic rats. They conclude that hypercapnia protects the blood-brain barrier. Possible mechanisms of this effect include attenuation of the incremental increase in pial venular pressure by hypercapnia or a direct effect on the blood-brain barrier not related to venous pressure.

  5. AltitudeOmics: enhanced cerebrovascular reactivity and ventilatory response to CO2 with high-altitude acclimatization and reexposure.

    PubMed

    Fan, Jui-Lin; Subudhi, Andrew W; Evero, Oghenero; Bourdillon, Nicolas; Kayser, Bengt; Lovering, Andrew T; Roach, Robert C

    2014-04-01

    The present study is the first to examine the effect of high-altitude acclimatization and reexposure on the responses of cerebral blood flow and ventilation to CO2. We also compared the steady-state estimates of these parameters during acclimatization with the modified rebreathing method. We assessed changes in steady-state responses of middle cerebral artery velocity (MCAv), cerebrovascular conductance index (CVCi), and ventilation (V(E)) to varied levels of CO2 in 21 lowlanders (9 women; 21 ± 1 years of age) at sea level (SL), during initial exposure to 5,260 m (ALT1), after 16 days of acclimatization (ALT16), and upon reexposure to altitude following either 7 (POST7) or 21 days (POST21) at low altitude (1,525 m). In the nonacclimatized state (ALT1), MCAv and V(E) responses to CO2 were elevated compared with those at SL (by 79 ± 75% and 14.8 ± 12.3 l/min, respectively; P = 0.004 and P = 0.011). Acclimatization at ALT16 further elevated both MCAv and Ve responses to CO2 compared with ALT1 (by 89 ± 70% and 48.3 ± 32.0 l/min, respectively; P < 0.001). The acclimatization gained for V(E) responses to CO2 at ALT16 was retained by 38% upon reexposure to altitude at POST7 (P = 0.004 vs. ALT1), whereas no retention was observed for the MCAv responses (P > 0.05). We found good agreement between steady-state and modified rebreathing estimates of MCAv and V(E) responses to CO2 across all three time points (P < 0.001, pooled data). Regardless of the method of assessment, altitude acclimatization elevates both the cerebrovascular and ventilatory responsiveness to CO2. Our data further demonstrate that this enhanced ventilatory CO2 response is partly retained after 7 days at low altitude.

  6. Effect of extracorporeal CO2 removal on right ventricular and hemodynamic parameters in a patient with acute respiratory distress syndrome.

    PubMed

    Cherpanath, Thomas G V; Landburg, Pearl P; Lagrand, Wim K; Schultz, Marcus J; Juffermans, Nicole P

    2016-09-01

    We present a female patient with severe acute respiratory distress syndrome (ARDS) necessitating intubation and mechanical ventilation on the intensive care unit (ICU). High ventilatory pressures were needed because of hypoxia and severe hypercapnia with respiratory acidosis, resulting in right ventricular dysfunction with impaired haemodynamic stability. A veno-venous extracorporeal CO2 removal (ECCO2R) circuit was initiated, effectively eliminating carbon dioxide while improving oxygenation and enabling a reduction in applied ventilatory pressures. We noted a marked improvement of right ventricular function with restoration of haemodynamic stability. Within one week, the patient was weaned from both ECCO2R and mechanical ventilation. Besides providing adequate gas exchange, extracorporeal assist devices may be helpful in ameliorating right ventricular dysfunction during ARDS.

  7. Pathophysiological Basis of Acute Respiratory Failure on Non-Invasive Mechanical Ventilation.

    PubMed

    Romero-Dapueto, C; Budini, H; Cerpa, F; Caceres, D; Hidalgo, V; Gutiérrez, T; Keymer, J; Pérez, R; Molina, J; Giugliano-Jaramillo, C

    2015-01-01

    Noninvasive mechanical ventilation (NIMV) was created for patients who needed noninvasive ventilator support, this procedure decreases the complications associated with the use of endotracheal intubation (ETT). The application of NIMV has acquired major relevance in the last few years in the management of acute respiratory failure (ARF), in patients with hypoxemic and hypercapnic failure. The main advantage of NIMV as compared to invasive mechanical ventilation (IMV) is that it can be used earlier outside intensive care units (ICUs). The evidence strongly supports its use in patients with COPD exacerbation, support in weaning process in chronic obstructive pulmonary disease (COPD) patients, patients with acute cardiogenic pulmonary edema (ACPE), and Immunosuppressed patients. On the other hand, there is poor evidence that supports the use of NIMV in other pathologies such as pneumonia, acute respiratory distress syndrome (ARDS), and during procedures as bronchoscopy, where its use is still controversial because the results of these studies are inconclusive against the decrease in the rate of intubation or mortality.

  8. Pathophysiological Basis of Acute Respiratory Failure on Non-Invasive Mechanical Ventilation

    PubMed Central

    Romero-Dapueto, C; Budini, H; Cerpa, F; Caceres, D; Hidalgo, V; Gutiérrez, T; Keymer, J; Pérez, R; Molina, J; Giugliano-Jaramillo, C

    2015-01-01

    Noninvasive mechanical ventilation (NIMV) was created for patients who needed noninvasive ventilator support, this procedure decreases the complications associated with the use of endotracheal intubation (ETT). The application of NIMV has acquired major relevance in the last few years in the management of acute respiratory failure (ARF), in patients with hypoxemic and hypercapnic failure. The main advantage of NIMV as compared to invasive mechanical ventilation (IMV) is that it can be used earlier outside intensive care units (ICUs). The evidence strongly supports its use in patients with COPD exacerbation, support in weaning process in chronic obstructive pulmonary disease (COPD) patients, patients with acute cardiogenic pulmonary edema (ACPE), and Immunosuppressed patients. On the other hand, there is poor evidence that supports the use of NIMV in other pathologies such as pneumonia, acute respiratory distress syndrome (ARDS), and during procedures as bronchoscopy, where its use is still controversial because the results of these studies are inconclusive against the decrease in the rate of intubation or mortality. PMID:26312101

  9. The influence of gender and upper airway resistance on the ventilatory response to arousal in obstructive sleep apnoea in humans

    PubMed Central

    Jordan, Amy S; McEvoy, R Doug; Edwards, Jill K; Schory, Karen; Yang, Chang-Kook; Catcheside, Peter G; Fogel, Robert B; Malhotra, Atul; White, David P

    2004-01-01

    The termination of obstructive respiratory events is typically associated with arousal from sleep. The ventilatory response to arousal may be an important determinant of subsequent respiratory stability/instability and therefore may be involved in perpetuating obstructive respiratory events. In healthy subjects arousal is associated with brief hyperventilation followed by more prolonged hypoventilation on return to sleep. This study was designed to assess whether elevated sleeping upper airway resistance (RUA) alters the ventilatory response to arousal and subsequent breathing on return to sleep in patients with obstructive sleep apnoea (OSA). Inspired minute ventilation (VI), RUA and end-tidal CO2 pressure (PET,CO2) were measured in 22 patients (11 men, 11 women) with OSA (mean ±s.e.m., apnoea–hypopnoea index (AHI) 48.9 ± 5.9 events h−1) during non-rapid eye movement (NREM) sleep with low RUA (2.8 ± 0.3 cmH2O l−1 s; optimal continuous positive airway pressure (CPAP) = 11.3 ± 0.7 cmH2O) and with elevated RUA (17.6 ± 2.8 cmH2O l−1 s; sub-optimal CPAP = 8.4 ± 0.8 cmH2O). A single observer, unaware of respiratory data, identified spontaneous and tone-induced arousals of 3–15 s duration preceded and followed by stable NREM sleep. VI was compared between CPAP levels before and after spontaneous arousal in 16 subjects with tone-induced arousals in both conditions. During stable NREM sleep at sub-optimal CPAP, PET,CO2 was mildly elevated (43.5 ± 0.8 versus 42.5 ± 0.8 Torr). However, baseline VI (7.8 ± 0.3 versus 8.0 ± 0.3 l min−1) was unchanged between CPAP conditions. For the first three breaths following arousal, VI was higher for sub-optimal than optimal CPAP (first breath: 11.2 ± 0.9 versus 9.3 ± 0.6 l min−1). The magnitude of hypoventilation on return to sleep was not affected by the level of CPAP and both obstructive and central respiratory events were rare following arousal. Similar results occurred after tone-induced arousals which led to

  10. [Non-invasive and invasive mechanical ventilation for treatment of chronic respiratory failure. S2-Guidelines published by the German Medical Association of Pneumology and Ventilatory Support].

    PubMed

    Windisch, W; Brambring, J; Budweiser, S; Dellweg, D; Geiseler, J; Gerhard, F; Köhnlein, T; Mellies, U; Schönhofer, B; Schucher, B; Siemon, K; Walterspacher, S; Winterholler, M; Sitter, H

    2010-04-01

    The field of mechanical ventilation is highly important in pulmonary medicine. The German Medical Association of Pneumology and Ventilatory Support ["Deutsche Gesellschaft für Pneumologie und Beatmungsmedizin e. V. (DGP)"] therefore has formulated these guidelines for home mechanical non-invasive and invasive ventilation. Non-invasive home mechanical ventilation can be administered using various facial masks; invasive home mechanical ventilation is performed via a tracheostomy. Home mechanical ventilation is widely and increasingly accepted as a treatment option for chronic ventilatory failure which most often occurs in COPD, restrictive lung diseases, obesity-hypoventilation syndrome and neuromuscular disorders. Essential for the initiation of home mechanical ventilation are the presence of symptoms of ventilatory failure and the detection of hypoventilation, most importantly hypercapnia. These guidelines comprise general indication criteria along with disease-specific criteria summarised by treatment algorithms. In addition, the management of bronchial secretions and care of paediatric patients are addressed. Home mechanical ventilation must be organised around a specialised respiratory care centre with expertise in patient selection, the initiation and the control of home mechanical ventilation. In this regard, the guidelines provide detailed information about technical requirements (equipment), control and settings of mechanical ventilation as well as organisation of patient care. A key requirement for home mechanical ventilation is the qualification of specialised home-care services, which is addressed in detail. Independent living and the quality of respiratory care are of highest priority in patients receiving home mechanical ventilation, since home mechanical ventilation can interfere with the integrity of a patient and often marks a life-sustaining therapy. Home mechanical ventilation has been shown to improve health-related quality of life of patients

  11. Patient transitions relevant to individuals requiring ongoing ventilatory assistance: A Delphi study

    PubMed Central

    Rose, Louise; Fowler, Robert A; Goldstein, Roger; Katz, Sherri; Leasa, David; Pedersen, Cheryl; McKim, Douglas

    2014-01-01

    BACKGROUND: Various terms, including ‘prolonged mechanical ventilation’ (PMV) and ‘long-term mechanical ventilation’ (LTMV), are used interchangeably to distinguish patient cohorts requiring ventilation, making comparisons and timing of clinical decision making problematic. OBJECTIVE: To develop expert, consensus-based criteria associated with care transitions to distinguish cohorts of ventilated patients. METHODS: A four-round (R), web-based Delphi study with consensus defined as >70% was performed. In R1, participants listed, using free text, criteria perceived to should and should not define seven transitions. Transitions comprised: T1 – acute ventilation to PMV; T2 – PMV to LTMV; T3 – PMV or LTMV to acute ventilation (reverse transition); T4 – institutional to community care; T5 – no ventilation to requiring LTMV; T6 – pediatric to adult LTMV; and T7 – active treatment to end-of-life care. Subsequent Rs sought consensus. RESULTS: Experts from intensive care (n=14), long-term care (n=14) and home ventilation (n=10), representing a variety of professional groups and geographical areas, completed all Rs. Consensus was reached on 14 of 20 statements defining T1 and 21 of 25 for T2. ‘Physiological stability’ had the highest consensus (97% and 100%, respectively). ‘Duration of ventilation’ did not achieve consensus. Consensus was achieved on 13 of 18 statements for T3 and 23 of 25 statements for T4. T4 statements reaching 100% consensus included: ‘informed choice’, ‘patient stability’, ‘informal caregiver support’, ‘caregiver knowledge’, ‘environment modification’, ‘supportive network’ and ‘access to interprofessional care’. Consensus was achieved for 15 of 17 T5, 16 of 20 T6 and 21 of 24 T7 items. CONCLUSION: Criteria to consider during key care transitions for ventilator-assisted individuals were identified. Such information will assist in furthering the consistency of clinical care plans, research trials

  12. Ventilatory responses during and following exposure to a hypoxic challenge in conscious mice deficient or null in S-nitrosoglutathione reductase

    PubMed Central

    Palmer, Lisa A; May, Walter J; deRonde, Kimberly; Brown-Steinke, Kathleen; Bates, James N; Gaston, Benjamin; Lewis, Stephen J

    2013-01-01

    Exposure to a hypoxic challenge increases ventilation in wild-type (WT) mice that diminish during the challenge (roll-off) whereas return to room air causes an increase in ventilation (short-term facilitation, STF). Since plasma and tissue levels of ventilatory excitant S-nitrosothiols such as S-nitrosoglutathione (GSNO) increase during hypoxia, this study examined whether (1) the initial increase in ventilation is due to generation of GSNO, (2) roll-off is due to increased activity of the GSNO degrading enzyme, GSNO reductase (GSNOR), and (3) STF is limited by GSNOR activity. Initial ventilatory responses to hypoxic challenge (10% O2, 90% N2) were similar in WT, GSNO+/− and GSNO−/− mice. These responses diminished markedly during hypoxic challenge in WT mice whereas there was minimal roll-off in GSNOR+/− and GSNOR−/− mice. Finally, STF was greater in GSNOR+/− and GSNOR−/− mice than WT mice (especially females). This study suggests that GSNOR degradation of GSNO is a vital step in the expression of ventilatory roll-off and that GSNOR suppresses STF. PMID:23183419

  13. Relationships (II) of International Classification of High-resolution Computed Tomography for Occupational and Environmental Respiratory Diseases with ventilatory functions indices for parenchymal abnormalities

    PubMed Central

    TAMURA, Taro; SUGANUMA, Narufumi; HERING, Kurt G.; VEHMAS, Tapio; ITOH, Harumi; AKIRA, Masanori; TAKASHIMA, Yoshihiro; HIRANO, Harukazu; KUSAKA, Yukinori

    2015-01-01

    The International Classification of High-Resolution Computed Tomography (HRCT) for Occupational and Environmental Respiratory Diseases (ICOERD) is used to screen and diagnose respiratory illnesses. Using univariate and multivariate analysis, we investigated the relationship between subject characteristics and parenchymal abnormalities according to ICOERD, and the results of ventilatory function tests (VFT). Thirty-five patients with and 27 controls without mineral-dust exposure underwent VFT and HRCT. We recorded all subjects’ occupational history for mineral dust exposure and smoking history. Experts independently assessed HRCT using the ICOERD parenchymal abnormalities (Items) grades for well-defined rounded opacities (RO), linear and/or irregular opacities (IR), and emphysema (EM). High-resolution computed tomography showed that 11 patients had RO; 15 patients, IR; and 19 patients, EM. According to the multiple regression model, age and height had significant associations with many indices ventilatory functions such as vital capacity, forced vital capacity, and forced expiratory volume in 1 s (FEV1). The EM summed grades on the upper, middle, and lower zones of the right and left lungs also had significant associations with FEV1 and the maximum mid-expiratory flow rate. The results suggest the ICOERD notation is adequate based on the good and significant multiple regression modeling of ventilatory function with the EM summed grades. PMID:25810443

  14. Neurally adjusted ventilatory assist during weaning from respiratory support in a case of guillain-barré syndrome.

    PubMed

    Dugernier, Jonathan; Bialais, Emilie; Reychler, Gregory; Vinetti, Marco; Hantson, Philippe

    2015-04-01

    We report a case of Guillain-Barré syndrome complicated by respiratory failure requiring mechanical ventilation. Neurally adjusted ventilatory assist (NAVA) allowed proper patient-ventilator synchronization by pressure support proportional to the electrical activity of the diaphragm (Edi). Prolonged ventilation with NAVA seems feasible in patients with neuromuscular impairment, but the weaning process conducted by a continuous monitoring of Edi for pressure support titration needed to be assessed in a Guillain-Barré syndrome patient. Beginning on day 12 after hospital admission, the patient was ventilated with NAVA for 8 d. The NAVA level (pressure support per unit of Edi) was decreased from 1.2 cm H2O/μV to zero over the 8-d period. A simultaneous decrease in the tidal volume/Edi ratio was interpreted as a sign of recovery. A spontaneous breathing trial was successfully performed on day 20, followed by decannulation 4 d later. In conclusion, NAVA should be further investigated in patients with Guillain-Barré syndrome, particularly during the weaning period.

  15. Limb movement frequency is a significant modulator of the ventilatory response during submaximal cycling exercise in humans.

    PubMed

    Caterini, Jessica E; Duffin, James; Wells, Gregory D

    2016-01-01

    Human experimentation investigating the contribution of limb movement frequency in determining the fast exercise drive to breathe has produced controversial findings. To evaluate the role of limb movement frequency in determining the fast exercise drive to breathe, endurance runners and recreationally-active controls performed two sinusoidal exercise protocols on a cycle ergometer. One protocol was performed at constant workload with sinusoidal pedaling cadence, and a second with sinusoidal workload at constant cadence. Metabolic rate (VO2) increases and means were matched between these two experiments. The ventilatory response was significantly faster when limb movement speed was varied, compared to when pedal loading was varied (18.49 ± 15.6s vs. 50.5 ± 14.5s, p<0.05). Ventilation response amplitudes were significantly higher during pedal cadence variation versus pedal loading variation (3.99 ± 0.25 vs. 2.58 ± 0.17 L/min, p<0.05). Similar findings were obtained for endurance athletes, with significantly attenuated ventilation responses to exercise versus control subjects. We conclude that fast changes in limb movement frequency are a potent stimulus for ventilation at submaximal workloads, and that this response is susceptible to attenuation through training.

  16. β-alanine Supplementation Fails to Increase Peak Aerobic Power or Ventilatory Threshold in Aerobically Trained Males.

    PubMed

    Greer, Beau Kjerulf; Katalinas, Matthew E; Shaholli, Danielle M; Gallo, Paul M

    2016-01-01

    The purpose of the present study was to determine the effect of 30 days of β-alanine supplementation on peak aerobic power and ventilatory threshold (VT) in aerobically fit males. Fourteen males (28.8 ± 9.8 yrs) were assigned to either a β-alanine (SUPP) or placebo (PLAC) group; groups were matched for VT as it was the primary outcome measure. β-alanine supplementation consisted of 3 g/day for 7 days, and 6 g/day for the remaining 23 days. Before and after the supplementation period, subjects performed a continuous, graded cycle ergometry test to determine VO2 peak and VT. Metabolic data were analyzed using a 2 × 2 ANOVA with repeated measures. Thirty days of β-alanine supplementation (SUPP) did not increase VO2 peak (4.05 ± 0.6 vs. 4.14 ± 0.6 L/min) as compared to the placebo (PLAC) group (3.88 ± 0.2 vs. 3.97 ± 0.2 L/min) (p > .05). VT did not significantly improve in either the SUPP (3.21 ± 0.5 vs. 3.33 ± 0.5 L/min) or PLAC (3.19 ± 0.1 vs. 3.20 ± 0.1 L/min) group (p > .05). In conclusion, 30 days of β-alanine supplementation had no effect on VO2 peak or VT in aerobically trained athletes.

  17. Activation of microglia and astrocytes in the nucleus tractus solitarius during ventilatory acclimatization to 10% hypoxia in unanesthetized mice.

    PubMed

    Tadmouri, A; Champagnat, J; Morin-Surun, M P

    2014-05-01

    Nucleus tractus solitarius (NTS) is the integrative sensory relay of autonomic functions in the brainstem. To explore the nonneuronal cellular basis of central chemosensitivity during the first 24 hr of ventilatory acclimatization to hypoxia (VHA), we have investigated glial activation markers in the NTS. Conscious mice (C57/BL6) were placed in a hermetic hypoxia chamber containing a plethysmograph to record ventilation. After 4 days of habituation to the normoxic environment, mice were subjected to physiological hypoxia (10% O2 ) for 1, 6, or 24 hr. To dissociate interactions between microglia and astrocytes, another group received daily minocycline, a microglia activation blocker. By immunochemical localization of astrocytes (GFAP), activated microglia (Cd11b), and total microglia (Iba-1), we identified an oxygen-sensing glial layer in the NTS, in which astrocytes are first activated after 1-6 hr of hypoxia, followed by microglia after 6-24 hr of hypoxia. Minocycline administration suppressed microglial activation and decreased astrocyte activation at 6 hr and VHA at 24 hr of hypoxia. These results suggest that astrocytes contribute to the neuronal response during the first hour of hypoxia, whereas microglial cells, via cross-talk with astrocytes, are involved in the VHA during the first 24 hr of acclimatization.

  18. Unusual Ventilatory Response to Exercise in Patient with Arnold-Chiari Type 1 Malformation after Posterior Fossa Decompression

    PubMed Central

    Smith, Keely; Gomez-Rubio, Ana M.; Harris, Tomika S.; Brooks, Lauren E.

    2016-01-01

    We present a case of a 17-year-old Hispanic male with Arnold-Chiari Type 1 [AC-Type 1] with syringomyelia, status post decompression, who complains of exercise intolerance, headaches, and fatigue with exertion. The patient was found to have diurnal hypercapnia and nocturnal alveolar hypoventilation. Cardiopulmonary testing revealed blunting of the ventilatory response to the rise in carbon dioxide (CO2) resulting in failure of the parallel correlation between increased CO2 levels and ventilation; the expected vertical relationship between PETCO2 and minute ventilation during exercise was replaced with an almost horizontal relationship. No new pathology of the brainstem was discovered by MRI or neurological evaluation to explain this phenomenon. The patient was placed on continuous noninvasive open ventilation (NIOV) during the day and CPAP at night for a period of 6 months. His pCO2 level decreased to normal limits and his symptoms improved; specifically, he experienced less headaches and fatigue during exercise. In this report, we describe the abnormal response to exercise that patients with AC-Type 1 could potentially experience, even after decompression, characterized by the impairment of ventilator response to hypercapnia during exertion, reflecting a complete loss of chemical influence on breathing with no evidence of abnormality in the corticospinal pathway. PMID:27418995

  19. Acute gastroenteritis.

    PubMed

    Graves, Nancy S

    2013-09-01

    Acute gastroenteritis is a common infectious disease syndrome, causing a combination of nausea, vomiting, diarrhea, and abdominal pain. There are more than 350 million cases of acute gastroenteritis in the United States annually and 48 million of these cases are caused by foodborne bacteria. Traveler's diarrhea affects more than half of people traveling from developed countries to developing countries. In adult and pediatric patients, the prevalence of Clostridium difficile is increasing. Contact precautions, public health education, and prudent use of antibiotics are necessary goals in decreasing the prevalence of Clostridium difficle. Preventing dehydration or providing appropriate rehydration is the primary supportive treatment of acute gastroenteritis.

  20. Increases in .VO2max with "live high-train low" altitude training: role of ventilatory acclimatization.

    PubMed

    Wilhite, Daniel P; Mickleborough, Timothy D; Laymon, Abigail S; Chapman, Robert F

    2013-02-01

    The purpose of this study was to estimate the percentage of the increase in whole body maximal oxygen consumption (.VO(2max)) that is accounted for by increased respiratory muscle oxygen uptake after altitude training. Six elite male distance runners (.VO(2max) = 70.6 ± 4.5 ml kg(-1) min(-1)) and one elite female distance runner (.VO(2max)) = 64.7 ml kg(-1) min(-1)) completed a 28-day "live high-train low" training intervention (living elevation, 2,150 m). Before and after altitude training, subjects ran at three submaximal speeds, and during a separate session, performed a graded exercise test to exhaustion. A regression equation derived from published data was used to estimate respiratory muscle .VO(2) (.VO(2RM)) using our ventilation (.VE) values. .VO(2RM) was also estimated retrospectively from a larger group of distance runners (n = 22). .VO(2max) significantly (p < 0.05) increased from pre- to post-altitude (196 ± 59 ml min(-1)), while (.VE) at .VO(2max) also significantly (p < 0.05) increased (13.3 ± 5.3 l min(-1)). The estimated .VO(2RM) contributed 37 % of Δ .VO(2max). The retrospective group also saw a significant increase in .VO(2max) from pre- to post-altitude (201 ± 36 ml min(-1)), along with a 10.8 ± 2.1 l min(-1) increase in (.VE), thus requiring an estimated 27 % of Δ .VO(2max) Our data suggest that a substantial portion of the improvement in .VO(2max) with chronic altitude training goes to fuel the respiratory muscles as opposed to the musculature which directly contributes to locomotion. Consequently, the time-course of decay in ventilatory acclimatization following return to sea-level may have an impact on competitive performance.

  1. The modified Dmax method is reliable to predict the second ventilatory threshold in elite cross-country skiers.

    PubMed

    Fabre, Nicolas; Balestreri, Filippo; Pellegrini, Barbara; Schena, Federico

    2010-06-01

    This study was designed to evaluate, in elite cross-country skiers, the capacity of the DMAX lactate threshold method and its modified version (DMAX MOD) to accurately predict the second ventilatory threshold (VT2). Twenty-three elite cross-country skiers carried out an incremental roller-ski test on a motorized treadmill. Ventilation, heart rate (HR), and gas exchanges were continuously recorded during the test. Blood was sampled at the end of each 3-minute work stage for lactate concentration measurements. The VT2 was individually determined by visual analysis. The DMAX, DMAX MOD points also with the 4 mmol.L(-1) fixed lactate concentration value (4 mM) were determined by a computerized program. Paired t tests showed nonsignificant differences between HR at VT2 and HR at DMAX MOD, between HR at VT2 and HR at 4 mM, and between HR at DMAX MOD and HR at 4 mM. HR at DMAX was significantly lower than HR at VT2, DMAX MOD, and at 4 mM (p<0.001). HR at VT2 was strongly correlated with HR at 4 mM (r=0.93, p<0.001), HR at DMAX (r=0.97, p<0.001) and especially with HR at DMAX MOD (r=0.99, p<0.001). Bland-Altman plots showed that HR at DMAX underestimated HR at VT2 and permitted to observe that the DMAX method and particularly the DMAX MOD method had smaller limits of agreement as compared with the 4 mM method. Our results showed that the DMAX MOD lactate threshold measurement is extremely accurate to predict VT2 in elite cross-country skiers.

  2. Acute Bronchitis

    MedlinePlus

    ... bronchitis? Acute bronchitis is almost always caused by viruses that attack the lining of the bronchial tree ... infection. As your body fights back against these viruses, more swelling occurs and more mucus is produced. ...

  3. Acute Pericarditis

    MedlinePlus

    ... large pericardial effusions). Acute pericarditis usually responds to colchicine or NSAIDs (such as aspirin and ibuprofen ) taken ... reduce pain but relieves it by reducing inflammation. Colchicine also decreases the chance of pericarditis returning later. ...

  4. No effect of arm-crank exercise on diaphragmatic fatigue or ventilatory constraint in Paralympic athletes with cervical spinal cord injury.

    PubMed

    Taylor, Bryan J; West, Christopher R; Romer, Lee M

    2010-08-01

    Cervical spinal cord injury (CSCI) results in a decrease in the capacity of the lungs and chest wall for pressure, volume, and airflow generation. We asked whether such impairments might increase the potential for exercise-induced diaphragmatic fatigue and mechanical ventilatory constraint in this population. Seven Paralympic wheelchair rugby players (mean + or - SD peak oxygen uptake = 16.9 + or - 4.9 ml x kg(-1) x min(-1)) with traumatic CSCI (C(5)-C(7)) performed arm-crank exercise to the limit of tolerance at 90% of their predetermined peak work rate. Diaphragm function was assessed before and 15 and 30 min after exercise by measuring the twitch transdiaphragmatic pressure (P(di,tw)) response to bilateral anterolateral magnetic stimulation of the phrenic nerves. Ventilatory constraint was assessed by measuring the tidal flow volume responses to exercise in relation to the maximal flow volume envelope. P(di,tw) was not different from baseline at any time after exercise (unpotentiated P(di,tw) = 19.3 + or - 5.6 cmH(2)O at baseline, 19.8 + or - 5.0 cmH(2)O at 15 min after exercise, and 19.4 + or - 5.7 cmH(2)O at 30 min after exercise; P = 0.16). During exercise, there was a sudden, sustained rise in operating lung volumes and an eightfold increase in the work of breathing. However, only two subjects showed expiratory flow limitation, and there was substantial capacity to increase both flow and volume (<50% of maximal breathing reserve). In conclusion, highly trained athletes with CSCI do not develop exercise-induced diaphragmatic fatigue and rarely reach mechanical ventilatory constraint. PMID:20489038

  5. Clinical review: Acute respiratory distress syndrome - clinical ventilator management and adjunct therapy

    PubMed Central

    2013-01-01

    Acute respiratory distress syndrome (ARDS) is a potentially devastating form of acute inflammatory lung injury with a high short-term mortality rate and significant long-term consequences among survivors. Supportive care, principally with mechanical ventilation, remains the cornerstone of therapy - although the goals of this support have changed in recent years - from maintaining normal physiological parameters to avoiding ventilator-induced lung injury while providing adequate gas exchange. In this article we discuss the current evidence base for ventilatory support and adjunctive therapies in patients with ARDS. Key components of such a strategy include avoiding lung overdistension by limiting tidal volumes and airway pressures, and the use of positive end-expiratory pressure with or without lung recruitment manoeuvres in patients with severe ARDS. Adjunctive therapies discussed include pharmacologic techniques (for example, vasodilators, diuretics, neuromuscular blockade) and nonpharmacologic techniques (for example, prone position, alternative modes of ventilation). PMID:23672857

  6. Individualized positive end-expiratory pressure application in patients with acute respiratory distress syndrome.

    PubMed

    Pintado, M C; de Pablo, R

    2014-11-01

    Current treatment of acute respiratory distress syndrome is based on ventilatory support with a lung protective strategy, avoiding the development of iatrogenic injury, including ventilator-induced lung injury. One of the mechanisms underlying such injury is atelectrauma, and positive end-expiratory pressure (PEEP) is advocated in order to avoid it. The indicated PEEP level has not been defined, and in many cases is based on the patient oxygen requirements for maintaining adequate oxygenation. However, this strategy does not consider the mechanics of the respiratory system, which varies in each patient and depends on many factors-including particularly the duration of acute respiratory distress syndrome. A review is therefore made of the different methods for adjusting PEEP, focusing on the benefits of individualized application.

  7. Individualized positive end-expiratory pressure application in patients with acute respiratory distress syndrome.

    PubMed

    Pintado, M C; de Pablo, R

    2014-11-01

    Current treatment of acute respiratory distress syndrome is based on ventilatory support with a lung protective strategy, avoiding the development of iatrogenic injury, including ventilator-induced lung injury. One of the mechanisms underlying such injury is atelectrauma, and positive end-expiratory pressure (PEEP) is advocated in order to avoid it. The indicated PEEP level has not been defined, and in many cases is based on the patient oxygen requirements for maintaining adequate oxygenation. However, this strategy does not consider the mechanics of the respiratory system, which varies in each patient and depends on many factors-including particularly the duration of acute respiratory distress syndrome. A review is therefore made of the different methods for adjusting PEEP, focusing on the benefits of individualized application. PMID:24485531

  8. Comparison of heart rate deflection and ventilatory threshold during a field cross-country roller-skiing test.

    PubMed

    Fabre, Nicolas; Passelergue, Philippe; Bouvard, Marc; Perrey, Stéphane

    2008-11-01

    This study was to assess whether the point of deflection from linearity of heart rate (HRd) could be an accurate predictor of ventilatory threshold (VT2) during a specific cross-country roller-skiing (RS) test. Ten well-trained cross-country skiers performed a maximal and incremental RS test in the field and a standardized maximal and incremental treadmill running (TR) test in the laboratory. Values of oxygen uptake (VO2) and heart rate (HR) were continuously recorded during all exercises by a portable breath-by-breath gas exchange measurement system and a wireless Polar monitoring system, respectively. The VT2 and HRd points were individually determined by visual analysis during RS. Maximal VO2 (VO2 max) and HR were higher (p < 0.05) during TR (67.1 +/- 7.3 ml x min(-1) x kg(-1) and 196.0 +/- 14.1 bpm, respectively) compared with RS (64.2 +/- 7.3 ml x min(-1) x kg(-1) and 191.5 +/- 13.1 bpm, respectively). However, a high correlation (r = 0.94, p < 0.01) between TR and VO2 max was observed. Paired t-tests showed no significant differences in HR (183.6 +/- 15.1 vs. 185.2 +/- 13.9 bpm) and VO2 (55.5 +/- 7.1 vs. 55.8 +/- 6.1 ml x min(-1) x kg(-1)) at intensities corresponding to HRd and VT2 during the RS test, respectively; Pearson product-moment correlation coefficients demonstrated significant relationships for HR at the HRd and VT2 points (r = 0.99, p < 0.001) as well as for VO2 (r = 0.95, p < 0.001). Our results indicate that the specific incremental RS test is effective in eliciting HRd in the field for all skiers and is an accurate predictor of VT2. These findings give very interesting practical applications to cross-country coaches and skiers to evaluate and control specific aerobic training loads.

  9. Acute lung injury after inhalation of nitric acid.

    PubMed

    Kao, Shih Ling; Yap, Eng Soo; Khoo, See Meng; Lim, Tow Keang; Mukhopadhyay, Amartya; Teo, Sylvia Tzu Li

    2008-12-01

    We report two cases of acute lung injury after the inhalation of nitric acid fumes in an industrial accident. The first patient, who was not using a respirator and standing in close proximity to the site of spillage of concentrated nitric acid, presented within 12 h with worsening dyspnea and required noninvasive ventilation for type 1 respiratory failure. The second case presented 1 day later with similar symptoms, but only required supportive treatment with high-flow oxygen. Both patients' chest radiographs showed widespread bilateral airspace shadows consistent with acute lung injury. Both received treatment with systemic steroids. They were discharged from hospital 5 days postexposure. Initial lung function test showed a restrictive pattern that normalized by 3 weeks postexposure. This case series describes the natural history after acute inhalation of nitric acid fumes, and demonstrates that the severity of lung injury is directly dependent on the exposure level. It also highlights the use of noninvasive ventilatory support in the management of such patients.

  10. Acute Pancreatitis

    PubMed Central

    Geokas, Michael C.

    1972-01-01

    For many decades two types of acute pancreatitis have been recognized: the edematous or interstitial and the hemorrhagic or necrotic. In most cases acute pancreatitis is associated with alcoholism or biliary tract disease. Elevated serum or urinary α-amylase is the most important finding in diagnosis. The presence of methemalbumin in serum and in peritoneal or pleural fluid supports the diagnosis of the hemorrhagic form of the disease in patients with a history and enzyme studies suggestive of pancreatitis. There is no characteristic clinical picture in acute pancreatitis, and its complications are legion. Pancreatic pseudocyst is probably the most common and pancreatic abscess is the most serious complication. The pathogenetic principle is autodigestion, but the precise sequence of biochemical events is unclear, especially the mode of trypsinogen activation and the role of lysosomal hydrolases. A host of metabolic derangements have been identified in acute pancreatitis, involving lipid, glucose, calcium and magnesium metabolism and changes of the blood clotting mechanism, to name but a few. Medical treatment includes intestinal decompression, analgesics, correction of hypovolemia and other supportive and protective measures. Surgical exploration is advisable in selected cases, when the diagnosis is in doubt, and is considered imperative in the presence of certain complications, especially pancreatic abscess. PMID:4559467

  11. Acute exposure to acid fog. Effects on mucociliary clearance

    SciTech Connect

    Laube, B.L.; Bowes, S.M. III; Links, J.M.; Thomas, K.K.; Frank, R. )

    1993-05-01

    Submicrometric sulfuric acid (H2SO4) aerosol can affect mucociliary clearance without eliciting irritative symptoms or changes in pulmonary function. The effect of larger fog droplets containing H2SO4 on mucociliary clearance is unknown. We quantified mucociliary clearance from the trachea (n = 4) and small airways (n = 7) of young healthy male adults after an acute exposure to H2SO4 fog (MMAD = 10.3 microns; pH = 2.0; liquid water content = 481 +/- 65 mg/m3; osmolarity = 30 mOsm). Acid fog (AF) or saline fog (SF) (10.9 microns; 492 +/- 116 mg/m3; 30 mOsm) was administered for 40 min of unencumbered breathing (no mouth-piece) at rest and for 20 min of exercise sufficient to produce oronasal breathing. Fog exposures were followed by a methacholine (MCh) challenge (a measure of airway reactivity) or inhalation of technetium-99M radioaerosol (MMAD = 3.4 microns) on 2 study days each. Changes in symptoms and forced ventilatory function were also assessed. Clearance was quantified from computer-assisted analyses of gamma camera images of the lower respiratory tract in terms of %removal/min of the radiolabel from the trachea 25 min after inhalation and from the outer zone of the right lung after 1.9 to 3 h. Symptoms, forced ventilatory function, and MCh response were unaffected by either fog. Tracheal clearance was more rapid in four of four subjects after AF (0.83 +/- 1.58% removal/min) compared with that after SF (-0.54 +/- 0.85% removal/min). Outer zone clearance was more rapid in six of seven subjects after AF (0.22 +/- 0.15% removal/min) compared with that after SF (0.01 +/- 0.09% removal/min).

  12. Acute Vestibulopathy

    PubMed Central

    Cha, Yoon-Hee

    2011-01-01

    The presentation of acute vertigo may represent both a common benign disorder or a life threatening but rare one. Familiarity with the common peripheral vestibular disorders will allow the clinician to rapidly “rule-in” a benign disorder and recognize when further testing is required. Key features of vertigo required to make an accurate diagnosis are duration, chronicity, associated symptoms, and triggers. Bedside tests that are critical to the diagnosis of acute vertigo include the Dix-Hallpike maneuver and canalith repositioning manuever, occlusive ophthalmoscopy, and the head impulse test. The goal of this review is to provide the clinician with the clinical and pathophysiologic background of the most common disorders that present with vertigo to develop a logical differential diagnosis and management plan. PMID:23983835

  13. [Acute diarrhea].

    PubMed

    Burgmann, Konstantin; Schoepfer, Alain

    2014-09-01

    Diarrhea, defined as three or more loose or watery stools per day, represents a frequent problem in outpatients as well as inpatients. As most of the patients with acute diarrhea show a self-limiting disease course, the main challenge for the physician is to discriminate patients for whom symptomatic therapy is sufficient from those with severe disease course and threatening complications. This review aims to provide a practical guidance for such decisions.

  14. Non-invasive ventilation in immunocompromised patients with acute hypoxemic respiratory failure.

    PubMed

    Del Sorbo, Lorenzo; Jerath, Angela; Dres, Martin; Parotto, Matteo

    2016-03-01

    The survival rate of immunocompromised patients has improved over the past decades in light of remarkable progress in diagnostic and therapeutic options. Simultaneously, there has been an increase in the number of immunocompromised patients with life threatening complications requiring intensive care unit (ICU) treatment. ICU admission is necessary in up to 15% of patients with acute leukemia and 20% of bone marrow transplantation recipients, and the main reason for ICU referral in this patient population is acute hypoxemic respiratory failure, which is associated with a high mortality rate, particularly in patients requiring endotracheal intubation. The application of non-invasive ventilation (NIV), and thus the avoidance of endotracheal intubation and invasive mechanical ventilation with its side effects, appears therefore of great importance in this patient population. Early trials supported the benefits of NIV in these settings, and the 2011 Canadian guidelines for the use of NIV in critical care settings suggest the use of NIV in immune-compromised patients with a grade 2B recommendation. However, the very encouraging results from initial seminal trials were not confirmed in subsequent observational and randomized clinical studies, questioning the beneficial effect of NIV in immune-compromised patients. Based on these observations, a French group led by Azoulay decided to assess whether early intermittent respiratory support with NIV had a role in reducing the mortality rate of immune-compromised patients with non-hypercapnic hypoxemic respiratory failure developed in less than 72 h, and hence conducted a multicenter randomized controlled trial (RCT) in experienced ICUs in France. This perspective reviews the findings from their RCT in the context of the current critical care landscape, and in light of recent results from other trials focused on the early management of acute hypoxemic respiratory failure. PMID:27076972

  15. End-of-life discontinuation of destination therapy with cardiac and ventilatory support medical devices: physician-assisted death or allowing the patient to die?

    PubMed Central

    2010-01-01

    Background Bioethics and law distinguish between the practices of "physician-assisted death" and "allowing the patient to die." Discussion Advances in biotechnology have allowed medical devices to be used as destination therapy that are designed for the permanent support of cardiac function and/or respiration after irreversible loss of these spontaneous vital functions. For permanent support of cardiac function, single ventricle or biventricular mechanical assist devices and total artificial hearts are implanted in the body. Mechanical ventilators extrinsic to the body are used for permanent support of respiration. Clinical studies have shown that destination therapy with ventricular assist devices improves patient survival compared to medical management, but at the cost of a substantial alteration in end-of-life trajectories. The moral and legal assessment of the appropriateness and permissibility of complying with a patient's request to electively discontinue destination therapy in a life-terminating act in non-futile situations has generated controversy. Some argue that complying with this request is ethically justified because patients have the right to request withdrawal of unwanted treatment and be allowed to die of preexisting disease. Other commentators reject the argument that acceding to an elective request for death by discontinuing destination therapy is 'allowing a patient to die' because of serious flaws in interpreting the intention, causation, and moral responsibility of the ensuing death. Summary Destination therapy with cardiac and/or ventilatory medical devices replaces native physiological functions and successfully treats a preexisting disease. We posit that discontinuing cardiac and/or ventilatory support at the request of a patient or surrogate can be viewed as allowing the patient to die if--and only if--concurrent lethal pathophysiological conditions are present that are unrelated to those functions already supported by medical devices in

  16. Divergent cardio-ventilatory and locomotor effects of centrally and peripherally administered urotensin II and urotensin II-related peptides in trout

    PubMed Central

    Vanegas, Gilmer; Leprince, Jérôme; Lancien, Frédéric; Mimassi, Nagi; Vaudry, Hubert; Le Mével, Jean-Claude

    2015-01-01

    The urotensin II (UII) gene family consists of four paralogous genes called UII, UII-related peptide (URP), URP1 and URP2. UII and URP peptides exhibit the same cyclic hexapeptide core sequence (CFWKYC) while the N- and C-terminal regions are variable. UII, URP1, and URP2 mRNAs are differentially expressed within the central nervous system of teleost fishes, suggesting that they may exert distinct functions. Although the cardiovascular, ventilatory and locomotor effects of UII have been described in teleosts, much less is known regarding the physiological actions of URPs. The goal of the present study was to compare the central and peripheral actions of picomolar doses (5–500 pmol) of trout UII, URP1, and URP2 on cardio-ventilatory variables and locomotor activity in the unanesthetized trout. Compared to vehicle, intracerebroventricular injection of UII, URP1 and URP2 evoked a gradual increase in total ventilation (VTOT) reaching statistical significance for doses of 50 and 500 pmol of UII and URP1 but for only 500 pmol of URP2. In addition, UII, URP1 and URP2 provoked an elevation of dorsal aortic blood pressure (PDA) accompanied with tachycardia. All peptides caused an increase in locomotor activity (ACT), at a threshold dose of 5 pmol for UII and URP1, and 50 pmol for URP2. After intra-arterial (IA) injection, and in contrast to their central effects, only the highest dose of UII and URP1 significantly elevated VTOT and ACT. UII produced a dose-dependent hypertensive effect with concomitant bradycardia while URP1 increased PDA and heart rate after injection of only the highest dose of peptide. URP2 did not evoke any cardio-ventilatory or locomotor effect after IA injection. Collectively, these findings support the hypothesis that endogenous UII, URP1 and URP2 in the trout brain may act as neurotransmitters and/or neuromodulators acting synergistically or differentially to control the cardio-respiratory and locomotor systems. In the periphery, the only

  17. Divergent cardio-ventilatory and locomotor effects of centrally and peripherally administered urotensin II and urotensin II-related peptides in trout.

    PubMed

    Vanegas, Gilmer; Leprince, Jérôme; Lancien, Frédéric; Mimassi, Nagi; Vaudry, Hubert; Le Mével, Jean-Claude

    2015-01-01

    The urotensin II (UII) gene family consists of four paralogous genes called UII, UII-related peptide (URP), URP1 and URP2. UII and URP peptides exhibit the same cyclic hexapeptide core sequence (CFWKYC) while the N- and C-terminal regions are variable. UII, URP1, and URP2 mRNAs are differentially expressed within the central nervous system of teleost fishes, suggesting that they may exert distinct functions. Although the cardiovascular, ventilatory and locomotor effects of UII have been described in teleosts, much less is known regarding the physiological actions of URPs. The goal of the present study was to compare the central and peripheral actions of picomolar doses (5-500 pmol) of trout UII, URP1, and URP2 on cardio-ventilatory variables and locomotor activity in the unanesthetized trout. Compared to vehicle, intracerebroventricular injection of UII, URP1 and URP2 evoked a gradual increase in total ventilation (V TOT) reaching statistical significance for doses of 50 and 500 pmol of UII and URP1 but for only 500 pmol of URP2. In addition, UII, URP1 and URP2 provoked an elevation of dorsal aortic blood pressure (P DA) accompanied with tachycardia. All peptides caused an increase in locomotor activity (A CT), at a threshold dose of 5 pmol for UII and URP1, and 50 pmol for URP2. After intra-arterial (IA) injection, and in contrast to their central effects, only the highest dose of UII and URP1 significantly elevated V TOT and A CT. UII produced a dose-dependent hypertensive effect with concomitant bradycardia while URP1 increased P DA and heart rate after injection of only the highest dose of peptide. URP2 did not evoke any cardio-ventilatory or locomotor effect after IA injection. Collectively, these findings support the hypothesis that endogenous UII, URP1 and URP2 in the trout brain may act as neurotransmitters and/or neuromodulators acting synergistically or differentially to control the cardio-respiratory and locomotor systems. In the periphery, the only

  18. [The late sequelae of the systematic action of a complex of real diving factors on the pulmonary ventilatory function of deep-sea divers].

    PubMed

    Dmitruk, A I; Il'in, V N

    1992-01-01

    Parameters which characterize lung volumes, absolute and relative flow rates, breathing reserve, were found unchanged with increasing age and record of active dive service, and in some deep-divers these parameters were growing up. This was disclosed due to comparative analysis of lung ventilatory function changes in divers through certain amount of years of professional occupation. At the same time a significant decrease in small to middle calibre bronchi patency was noted. In 30% of experienced deep-divers the mean maximal forced expiratory flow at 75% forced vital capacity (FEF75) decreased to 39% of predicted value at one-second forced expiratory volume (FEV1) being normal. Maximal expiratory flow at 50% forced vital capacity (FEF50) were in inferior normal limit (52% of predicted value).

  19. Ventilatory and cardiovascular actions of centrally and peripherally administered trout pituitary adenylate cyclase-activating polypeptide (PACAP) and vasoactive intestinal peptide (VIP) in the unanaesthetized trout.

    PubMed

    Le Mével, J-C; Lancien, F; Mimassi, N; Conlon, J M

    2009-12-01

    In mammals, pituitary adenylate cyclase-activating polypeptide (PACAP) and vasoactive intestinal peptide (VIP) are involved in cardiovascular and respiratory regulation. Several studies have demonstrated the presence of PACAP, VIP and their receptors in various tissues of teleost fish, including the brain, but little is known about their respiratory and cardiovascular effects. The present study was undertaken to compare the central and peripheral actions of graded doses (25-100 pmol) of trout PACAP and trout VIP on ventilatory and cardiovascular variables in the unanaesthetized rainbow trout. Compared with vehicle, only intracerebroventricular injection of PACAP significantly (P<0.05) elevated the ventilation frequency and the ventilation amplitude, but both peptides significantly increased the total ventilation (total ventilation). However, the maximum hyperventilatory effect of PACAP was approximately 2.5-fold higher than the effect of VIP at the 100 pmol dose (PACAP, (total ventilation)=+5407+/-921 arbitrary units, a.u.; VIP, (total ventilation)=+2056+/-874 a.u.; means +/- s.e.m.). When injected centrally, only PACAP produced a significant increase in mean dorsal aortic blood pressure (P(DA)) (100 pmol: +21%) but neither peptide affected heart rate (f(H)). Intra-arterial injections of either PACAP or VIP were without effect on the ventilatory variables. PACAP was without significant action on P(DA) and f(H) while VIP significantly elevated P(DA) (100 pmol: +36%) without changing f(H). In conclusion, the selective central hyperventilatory actions of exogenously administered trout PACAP, and to a lesser extent VIP, suggest that the endogenous peptides may be implicated in important neuroregulatory functions related to the central control of ventilation in trout.

  20. [Acute gamma-butyrolactone poisoning with withdrawal syndrome].

    PubMed

    Chwaluk, Paweł; Rejmak, Grazyna

    2011-01-01

    Gamma-butyrolactone (GBL) is a solvent that are part of many consumer products and in most countries can be legally purchased in the form of almost pure substance. After ingestion GBL is rapidly converted to gamma-hydroxybutyric acid (GHB). In recent years, GBL became a legal alternative to GHB, which is used widely since 1990s as a club drug and date rape drug. It is believed that abuse of GBL is not frequent in Europe, except for certain specific groups, mainly in urban centers in the west of the continent. We present a case of acute GBL poisoning with the withdrawal syndrome in 23-year-old man living in a rural area in eastern Poland. The patient was admitted to the Intensive Care Unit (ICU) because of coma of unknown origin. On admission erosions of the lips and mouth was seen. Ethyl alcohol was not present in blood sample, urine screening tests for drugs were negative. During his stay in the ICU patient required ventilatory support, was periodically agitated with muscular jerks and opisthotonos. The later medical history revealed that the patient from two years used GBL, which purchased as wheels cleaner. The tolerance developed, and the interruption of use of substance triggered symptoms of withdrawal. GBL abuse occurs in different social groups and is at risk for acute toxicity and the development of physical dependence. PMID:22010460

  1. NIV-Helmet in Severe Hypoxemic Acute Respiratory Failure

    PubMed Central

    Martins, Joana; Nunes, P.; Silvestre, C.; Abadesso, C.; Loureiro, H.; Almeida, H.

    2015-01-01

    Noninvasive ventilation (NIV) is a method to be applied in acute respiratory failure, given the possibility of avoiding tracheal intubation and conventional ventilation. A previous healthy 5-month-old boy developed low-grade intermittent fever, flu-like symptoms, and dry cough for 3 days. On admission, he showed severe respiratory distress with SpO2/FiO2 ratio of 94. Subsequent evaluation identified an RSV infection complicated with an increase of inflammatory parameters (reactive C protein 15 mg/dL). Within the first hour after NIV-helmet CPAP SpO2/FiO2 ratio increased to 157. This sustained improvement allowed the continuing of this strategy. After 102 h, he was disconnected from the helmet CPAP device. The NIV use in severe hypoxemic acute respiratory failure should be carefully monitored as the absence of clinical improvement has a predictive value in the need to resume to intubation and mechanical ventilation. We emphasize that SpO2/FiO2 ratio is a valuable monitoring instrument. Helmet interface use represents a more comfortable alternative for providing ventilatory support, particularly to small infants, which constitute a sensitive group within pediatric patients. PMID:26000189

  2. Acute sinusitis.

    PubMed

    Feldt, Brent; Dion, Gregory R; Weitzel, Erik K; McMains, Kevin C

    2013-10-01

    Sinusitis is a common patient complaint that carries with it a large economic burden. It is one of the most common reasons patients visit their primary care physician. Acute bacterial rhinosinusitis (ABRS) can be distinguished from other forms of rhinosinusitis based on symptom duration of <4 weeks in a patient with purulent rhinorrhea associated with facial pain or pressure. Native upper aerodigestive tract bacteria are the most common etiologic agents. Treatment of ABRS is targeted primarily at symptom improvement. Amoxicillin can be used based on the clinical scenario and patient comorbidities. Computed tomographic scans are reserved for complicated presentations or when there is concern for intracranial extension or other complications. A systematic approach to ABRS will allow for improved patient quality of life and a decreased overall economic burden of this common entity.

  3. Reactive airways dysfunction syndrome from acute inhalation of a dishwasher detergent powder.

    PubMed

    Hannu, Timo J; Riihimäki, Vesa E; Piirilä, Päivi L

    2012-01-01

    Reactive airway dysfunction syndrome, a type of occupational asthma without a latency period, is induced by irritating vapour, fumes or smoke. The present report is the first to describe a case of reactive airway dysfunction syndrome caused by acute exposure to dishwater detergent containing sodium metasilicate and sodium dichloroisocyanurate. The diagnosis was based on exposure data, clinical symptoms and signs, as well as respiratory function tests. A 43-year-old nonatopic male apprentice cook developed respiratory symptoms immediately after exposure to a cloud of detergent powder that was made airborne by vigorous shaking of the package. In spirometry, combined obstructive and restrictive ventilatory impairment developed, and the histamine challenge test revealed bronchial hyper-responsiveness. Even routine handling of a strongly caustic detergent, such as filling a dishwasher container, is not entirely risk free and should be performed with caution. PMID:22679618

  4. Reactive airways dysfunction syndrome from acute inhalation of dishwasher detergent powder

    PubMed Central

    Hannu, Timo J; Riihimäki, Vesa E; Piirilä, Päivi L

    2012-01-01

    Reactive airway dysfunction syndrome, a type of occupational asthma without a latency period, is induced by irritating vapour, fumes or smoke. The present report is the first to describe a case of reactive airway dysfunction syndrome caused by acute exposure to dishwater detergent containing sodium metasilicate and sodium dichloroisocyanurate. The diagnosis was based on exposure data, clinical symptoms and signs, as well as respiratory function tests. A 43-year-old nonatopic male apprentice cook developed respiratory symptoms immediately after exposure to a cloud of detergent powder that was made airborne by vigorous shaking of the package. In spirometry, combined obstructive and restrictive ventilatory impairment developed, and the histamine challenge test revealed bronchial hyper-responsiveness. Even routine handling of a strongly caustic detergent, such as filling a dishwasher container, is not entirely risk free and should be performed with caution. PMID:22679618

  5. Acute epiglottitis in a rural area: experiences with an anesthesiologist-staffed ambulance helicopter.

    PubMed

    Søreide, E; Smedvig, J P; Harboe, S; Mikkelsen, H; Eielsen, O V

    1994-01-01

    The majority of fatalities due to acute epiglottitis (AE) result from prehospital airway problems. We reviewed the courses of 14 patients with AE treated by an aeromedical team consisting of an anesthesiologist and a paramedic. Eight patients were transported from a physician's office or from the patient's own home. One patient was intubated at the scene, and two received ventilatory support with mask and bag en route to the hospital. Two patients suffered cardiopulmonary arrest before arrival of the aeromedical team, both resulting in severe hypoxic encephalopathy. All six patients transported from hospitals were intubated prior to the helicopter transport. Based on our own experience and a review of the literature, we discuss prehospital airway management in this group of patients. PMID:8207158

  6. Bilevel ventilation during exercise in acute on chronic respiratory failure: a preliminary study.

    PubMed

    Menadue, Collette; Alison, J A; Piper, A J; Flunt, D; Ellis, E R

    2010-02-01

    To determine the immediate effects of bilevel non-invasive ventilation plus oxygen (NIV+O(2)) during exercise compared to exercise with O(2) alone in people recovering from acute on chronic hypercapnic respiratory failure (HRF), a randomised crossover study with repeated measures was performed. Eighteen participants performed six minute walk tests (6MWT) and 16 participants performed unsupported arm exercise (UAE) tests with NIV+O(2) and with O(2) alone in random order. Distance walked increased by a mean of 43.4m (95% CI 14.1 to 72.8, p=0.006) with NIV+O(2) compared to exercise with O(2) alone. In addition, isotime oxygen saturation increased by a mean of 5% (95% CI 2-7, p=0.001) and isotime dyspnoea was reduced [median 2 (interquartile range (IQR) 1-4) versus 4 (3-5), p=0.028] with NIV+O(2). A statistically significant increase was also observed in UAE endurance time with NIV+O(2) [median 201s (IQR 93-414) versus 157 (90-342), p=0.033], and isotime perceived exertion (arm muscle fatigue) was reduced by a mean of 1.0 on the Borg scale (95% CI -1.9 to -0.1, p=0.037) compared with O(2) alone. Non-invasive ventilation plus O(2) during walking resulted in an immediate improvement in distance walked and oxygen saturation, and a reduction in dyspnoea compared to exercise with O(2) alone in people recovering from acute on chronic HRF. The reduction of dyspnoea during walking and arm muscle fatigue during UAE observed with NIV+O(2) may allow patients to better tolerate exercise early in the recovery period. PMID:19804963

  7. Central Sleep Apnea at High Altitude.

    PubMed

    Burgess, Keith R; Ainslie, Philip N

    2016-01-01

    The discovery of central sleep apnea (CSA) at high altitude is usually attributed to Angelo Mosso who published in 1898. It can occur in susceptible individuals at altitude above 2000 m, but at very high altitude, say above 5000 m, it will occur in most subjects. Severity is correlated with ventilatory responsiveness, particularly to hypoxia. Theoretically, it should spontaneously improve with time and acclimatization. Although the time course of resolution is not well described, it appears to persist for more than a month at 5000 m.It occurs due to the interaction of hypocapnia with stages 1 and 2 NREM sleep, in the presence of increased loop-gain. The hypocapnia is secondary to hypoxic ventilatory drive. With acclimatization, one might expect that the increase in PaO2 and cerebral blood flow (CBF) would mitigate the CSA. However, over time, both the hypoxic and hypercapnic ventilatory responses increase, causing an increase in loop gain which is a counteracting force.The severity of the CSA can be reduced by descent, supplemental oxygen therapy, oral or intravenous acetazolamide. Recent studies suggest that acute further increases in cerebral blood flow will substantially, but temporarily, reduce central sleep apnea, without altering acid based balance. Very recently, bi-level noninvasive ventilation has also been shown to help (mechanism unknown). Sleep quality can be improved independent of the presence of CSA by the use of benzodiazepine sedation. PMID:27343103

  8. Phase I/II trial of adeno-associated virus-mediated alpha-glucosidase gene therapy to the diaphragm for chronic respiratory failure in Pompe disease: initial safety and ventilatory outcomes.

    PubMed

    Smith, Barbara K; Collins, Shelley W; Conlon, Thomas J; Mah, Cathryn S; Lawson, Lee Ann; Martin, Anatole D; Fuller, David D; Cleaver, Brian D; Clément, Nathalie; Phillips, Dawn; Islam, Saleem; Dobjia, Nicole; Byrne, Barry J

    2013-06-01

    Pompe disease is an inherited neuromuscular disease caused by deficiency of lysosomal acid alpha-glucosidase (GAA) leading to glycogen accumulation in muscle and motoneurons. Cardiopulmonary failure in infancy leads to early mortality, and GAA enzyme replacement therapy (ERT) results in improved survival, reduction of cardiac hypertrophy, and developmental gains. However, many children have progressive ventilatory insufficiency and need additional support. Preclinical work shows that gene transfer restores phrenic neural activity and corrects ventilatory deficits. Here we present 180-day safety and ventilatory outcomes for five ventilator-dependent children in a phase I/II clinical trial of AAV-mediated GAA gene therapy (rAAV1-hGAA) following intradiaphragmatic delivery. We assessed whether rAAV1-hGAA results in acceptable safety outcomes and detectable functional changes, using general safety measures, immunological studies, and pulmonary functional testing. All subjects required chronic, full-time mechanical ventilation because of respiratory failure that was unresponsive to both ERT and preoperative muscle-conditioning exercises. After receiving a dose of either 1×10(12) vg (n=3) or 5×10(12) vg (n=2) of rAAV1-hGAA, the subjects' unassisted tidal volume was significantly larger (median [interquartile range] 28.8% increase [15.2-35.2], p<0.05). Further, most patients tolerated appreciably longer periods of unassisted breathing (425% increase [103-851], p=0.08). Gene transfer did not improve maximal inspiratory pressure. Expected levels of circulating antibodies and no T-cell-mediated immune responses to the vector (capsids) were observed. One subject demonstrated a slight increase in anti-GAA antibody that was not considered clinically significant. These results indicate that rAAV1-hGAA was safe and may lead to modest improvements in volitional ventilatory performance measures. Evaluation of the next five patients will determine whether earlier intervention can

  9. Diagnosis and prognostic value of restrictive ventilatory disorders in the elderly: a systematic review of the literature.

    PubMed

    Scarlata, Simone; Costanzo, Luisa; Giua, Renato; Pedone, Claudio; Incalzi, Raffaele Antonelli

    2012-04-01

    Although less extensively studied compared to pulmonary obstructive diseases, restrictive lung disease (RLD) is highly prevalent and frequently disabling in the adult and, more, the elderly population. The underlying conditions may be either primarily pulmonary diseases, such as idiopathic pulmonary fibrosis, or non respiratory conditions secondarily affecting the lung, e. g. congestive heart failure, or else conditions affecting the lung expansion, e. g. obesity or rib cage deformity. The diagnosis is frequently based on the measurement of surrogate indexes such as the forced vital capacity (FVC) used as a proxy for total lung capacity (TLC). As a consequence, diagnosis of RLD is often characterized by poor specificity. In the elderly, worsening in the quality of life and poor prognosis are variably, but significantly, associated to RLD, being the underlying condition an important source of variability. Several causes of RLD are preventable and treatable conditions. A prompt identification of these conditions may allow to slow the decline of respiratory reserve and, thus, to preserve both personal independence and resistance to acute respiratory infections. This review gives an update on the latest evidence available on the prevalence and the prognosis of RLD in the elderly. Studies were identified through systematic searches of the electronic database MEDLINE. Reference list of eligible papers were also manually searched. PMID:22370614

  10. Evaluation of chronic bronchitis, chronic obstructive pulmonary disease, and ventilatory function among workers exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin

    SciTech Connect

    Calvert, G.M.; Sweeney, M.H.; Morris, J.A.; Fingerhut, M.A.; Hornung, R.W.; Halperin, W.E. )

    1991-12-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is produced as an undesirable contaminant in the manufacture of 2,4,5-trichlorophenol (TCP) and its derivatives. There is considerable concern about the health effects that may be associated with exposure to TCDD-contaminated substances. A cross-sectional medical study that included a comprehensive medical history, medical examination, and measurement of pulmonary function was conducted on workers employed more than 15 yr earlier in the manufacture of NaTCP and its derivatives at two chemical plants. The workers had substantial exposure to substances contaminated with TCDD, as evidenced by a mean serum TCDD level, lipid adjusted, of 200 ppt compared with a mean of 7 ppt in the unexposed reference group. The comparison group consisted of individuals with no occupational exposure to phenoxy herbicides who lived in the same communities as the workers. A total of 281 workers and 260 unexposed referents participated in the medical examination. Logistic and linear regression analyses, which contained categorical and continuous measures of TCDD exposure, were performed to control for important confounders, including cigarette and alcohol consumption. No difference was found between workers and referents in the risk for chronic bronchitis or COPD. Analysis of the ventilatory function data revealed no association between history of exposure to substances contaminated with TCDD and the forced expiratory volume at one second (FEV1), forced vital capacity (FVC), or the ratio of FEV1 to FVC (FEV1/FVC%).

  11. Ventilatory accommodation of oxygen demand and respiratory water loss in kangaroos from mesic and arid environments, the eastern grey kangaroo (Macropus giganteus) and the red kangaroo (Macropus rufus).

    PubMed

    Dawson, T J; Munn, A J; Blaney, C E; Krockenberger, A; Maloney, S K

    2000-01-01

    We studied ventilation in kangaroos from mesic and arid environments, the eastern grey kangaroo (Macropus giganteus) and the red kangaroo (Macropus rufus), respectively, within the range of ambient temperatures (T(a)) from -5 degrees to 45 degrees C. At thermoneutral temperatures (Ta=25 degrees C), there were no differences between the species in respiratory frequency, tidal volume, total ventilation, or oxygen extraction. The ventilatory patterns of the kangaroos were markedly different from those predicted from the allometric equation derived for placentals. The kangaroos had low respiratory frequencies and higher tidal volumes, even when adjustment was made for their lower basal metabolism. At Ta>25 degrees C, ventilation was increased in the kangaroos to facilitate respiratory water loss, with percent oxygen extraction being markedly lowered. Ventilation was via the nares; the mouth was closed. Differences in ventilation between the two species occurred at higher temperatures, and at 45 degrees C were associated with differences in respiratory evaporative heat loss, with that of M. giganteus being higher. Panting in kangaroos occurred as a graded increase in respiratory frequency, during which tidal volume was lowered. When panting, the desert red kangaroo had larger tidal volumes and lower respiratory frequencies at equivalent T(a) than the eastern grey kangaroo, which generally inhabits mesic forests. The inference made from this pattern is that the red kangaroo has the potential to increase respiratory evaporative heat loss to a greater level.

  12. Pentoxifylline Treatment in Acute Pancreatitis (AP)

    ClinicalTrials.gov

    2016-09-14

    Acute Pancreatitis (AP); Gallstone Pancreatitis; Alcoholic Pancreatitis; Post-ERCP/Post-procedural Pancreatitis; Trauma Acute Pancreatitis; Hypertriglyceridemia Acute Pancreatitis; Idiopathic (Unknown) Acute Pancreatitis; Medication Induced Acute Pancreatitis; Cancer Acute Pancreatitis; Miscellaneous (i.e. Acute on Chronic Pancreatitis)

  13. Pharmacology of acute mountain sickness: old drugs and newer thinking.

    PubMed

    Swenson, Erik R

    2016-01-15

    Pharmacotherapy in acute mountain sickness (AMS) for the past half century has largely rested on the use of carbonic anhydrase (CA) inhibitors, such as acetazolamide, and corticosteroids, such as dexamethasone. The benefits of CA inhibitors are thought to arise from their known ventilatory stimulation and resultant greater arterial oxygenation from inhibition of renal CA and generation of a mild metabolic acidosis. The benefits of corticosteroids include their broad-based anti-inflammatory and anti-edemagenic effects. What has emerged from more recent work is the strong likelihood that drugs in both classes act on other pathways and signaling beyond their classical actions to prevent and treat AMS. For the CA inhibitors, these include reduction in aquaporin-mediated transmembrane water transport, anti-oxidant actions, vasodilation, and anti-inflammatory effects. In the case of corticosteroids, these include protection against increases in vascular endothelial and blood-brain barrier permeability, suppression of inflammatory cytokines and reactive oxygen species production, and sympatholysis. The loci of action of both classes of drug include the brain, but may also involve the lung as revealed by benefits that arise with selective administration to the lungs by inhalation. Greater understanding of their pluripotent actions and sites of action in AMS may help guide development of better drugs with more selective action and fewer side effects. PMID:26294748

  14. Acute respiratory failure due to refeeding syndrome and hypophosphatemia induced by hypocaloric enteral nutrition.

    PubMed

    Patel, Utpal; Sriram, Krishnan

    2009-03-01

    We report a case of acute respiratory failure due to refeeding syndrome caused by hypocaloric enteral tube feeds. A 60-y-old obese man, with a diagnosis of esophageal carcinoma with local metastases, underwent feeding jejunostomy tube insertion. Enteral tube feeding was initiated at small volumes providing 4.4 kcal x kg(-1) x d(-1) and gradually increased over 48 h to 29 kcal x kg(-1) x d(-1) (based on adjusted body weight). The patient then developed acute respiratory distress requiring intubation and ventilatory support. Serum phosphorus (P) level was extremely low at <0.7 mg/dL. Serum potassium (K) and magnesium (Mg) levels were also low. It took >4 d to adequately correct the electrolyte derangements. Successful liberation from mechanical ventilation was then possible. In chronically malnourished patients undergoing nutritional support, even hypocaloric feeding should be considered a risk factor for developing refeeding syndrome leading to severe and acute electrolyte fluid-balance and metabolic abnormalities.

  15. Acute Lymphocytic Leukemia

    MedlinePlus

    ... hard for blood to do its work. In acute lymphocytic leukemia (ALL), also called acute lymphoblastic leukemia, there are too ... of white blood cells called lymphocytes or lymphoblasts. ALL is the most common type of cancer in ...

  16. Acute kidney failure

    MedlinePlus

    Kidney failure; Renal failure; Renal failure - acute; ARF; Kidney injury - acute ... There are many possible causes of kidney damage. They include: ... cholesterol (cholesterol emboli) Decreased blood flow due to very ...

  17. Acute arterial occlusion - kidney

    MedlinePlus

    Acute renal arterial thrombosis; Renal artery embolism; Acute renal artery occlusion; Embolism - renal artery ... main artery to the kidney is called the renal artery. Reduced blood flow through the renal artery ...

  18. Acute cerebellar ataxia

    MedlinePlus

    Cerebellar ataxia; Ataxia - acute cerebellar; Cerebellitis; Post-varicella acute cerebellar ataxia; PVACA ... virus. Viral infections that may cause this include chickenpox , Coxsackie disease, Epstein-Barr, and echovirus . Other causes ...

  19. Effect of acute hypercapnia during 10-day hypoxic bed rest on posterior eye structures.

    PubMed

    Jaki Mekjavic, Polona; Lenassi, Eva; Eiken, Ola; Mekjavic, Igor B

    2016-05-15

    To gain insights into microgravity-induced ophthalmic changes (microgravity ocular syndrome), and as part of a project investigating effects of future planetary habitats, we investigated the effect of acute hypercapnia following 10-day bed rest and hypoxia on posterior eye structures. Female subjects (N = 7) completed three 10-day experimental interventions: 1) normoxic bed rest [NBR; partial pressure of inspired O2 (PiO2 ) = 132.9 ± 0.3 Torr]; 2) hypoxic ambulatory confinement (HAMB; PiO2 = 90.4 ± 0.3 Torr); and 3) hypoxic bed rest (HBR; n = 12; PiO2 = 90.4 ± 0.3 Torr). Before and on the last day of each intervention, optical coherence tomography (OCT) of the optic disk was performed, and the thicknesses of the retinal nerve fiber layer (RNFL), retina, and choroid were measured. OCT examinations were conducted with the subjects breathing the prevailing normocapnic breathing mixture (either normoxic or hypoxic) and then following a 10-min period of breathing the same gas mixture, but with the addition of 1% CO2 Choroidal thickness was greater during both bed-rest conditions (NBR and HBR) compared with the ambulatory (HAMB) condition (ANOVA, P < 0.001). Increases in RNFL thickness compared with baseline were observed in the hypoxic trials (HBR, P < 0.001; and HAMB, P = 0.021), but not the normoxic trial (NBR). A further increase in RNFL thickness (P = 0.019) was observed after the 10-min hypercapnic trial in the NBR condition only. The fact that choroidal thickness was not affected by Po2 or Pco2, but increased by bed rest, suggests a hydrostatic rather than a vasoactive effect. The increments in RNFL thickness were most likely associated with local hypoxia and hypercapnia-induced dilatation of the retinal blood vessels. PMID:27013607

  20. Use of a venting PEG tube in the management of recurrent acute gastric dilatation associated with Prader-Willi syndrome.

    PubMed

    Mohammed, Ahmed M A; Dennis, Robert J

    2016-01-01

    A patient with Prader-Willi Syndrome was admitted to the ICU with features of recurrent acute gastric dilatation, aspiration pneumonia and a massive pulmonary embolus. He was initially managed with intubation, assisted ventilation, intravenous fluids and anticoagulation. Decompression of the stomach was achieved with a nasogastric tube. After ventilator weaning, he did not tolerate the nasogastric intubation that led to a further episode of aspiration pneumonia as a result of non-resolving gastric dilatation. He required readmission to intensive care for a further period of ventilatory support. While the patient was sedated and ventilated, a venting percutaneous endoscopic gastrostomy (PEG) with a jejunal feeding extension was placed, permitting both continued decompression of the stomach and enteral feeding. The patient tolerated the PEG-J well and his nutritional needs were successfully addressed. Oral intake was slowly re-established with ongoing decompression of the stomach with the PEG. He was discharged from hospital with the PEG in place. PMID:26763981

  1. Interval training based on ventilatory anaerobic threshold increases cardiac vagal modulation and decreases high-sensitivity c-reative protein: randomized clinical trial in coronary artery disease

    PubMed Central

    Tamburus, Nayara Y.; Paula, Roberta F. L.; Kunz, Vandeni C.; César, Marcelo C.; Moreno, Marlene A.; da Silva, Ester

    2015-01-01

    Background: Autonomic dysfunction and inflammatory activity are involved in the development and progression of coronary artery disease (CAD), and exercise training has been shown to confer a cardiovascular benefit. Objective: To evaluate the effects that interval training (IT) based on ventilatory anaerobic threshold (VAT) has on heart rate variability (HRV) and high-sensitivity C-reactive protein (hs-CRP) levels, as well as the relationship between both levels, in patients with CAD and/or cardiovascular risk factors (RF). Method: Forty-two men (aged 57.88±6.20 years) were divided into two training groups, CAD-T (n= 12) and RF-T (n= 10), and two control groups, CAD-C (n= 10) and RF-C (n=10). Heart rate and RR intervals in the supine position, cardiopulmonary exercise tests, and hs-CRP levels were measured before and after IT. HRV was analyzed by spectral and symbolic analysis. The CAD-T and RF-T underwent a 16-week IT program of three weekly sessions at training intensities based on the VAT. Results: In the RF-T, cardiac sympathetic modulation index and hs-CRP decreased (p<0.02), while cardiac parasympathetic modulation index increased (p<0.02). In the CAD-T, cardiac parasympathetic modulation index increased, while hs-CRP, systolic, and diastolic blood pressures decreased (p<0.02). Both control groups showed increase in hs-CRP parameters (p<0.02). There was a strong and significant association between parasympathetic and sympathetic modulations with hs-CRP. Conclusion: The IT program based on the VAT promoted a decrease in hs-CRP associated with improvement in cardiac autonomic modulation. PMID:26647745

  2. Measuring the human ventilatory and cerebral blood flow response to CO2: a technical consideration for the end-tidal-to-arterial gas gradient.

    PubMed

    Tymko, Michael M; Hoiland, Ryan L; Kuca, Tomas; Boulet, Lindsey M; Tremblay, Joshua C; Pinske, Bryenna K; Williams, Alexandra M; Foster, Glen E

    2016-01-15

    Our aim was to quantify the end-tidal-to-arterial gas gradients for O2 (PET-PaO2) and CO2 (Pa-PETCO2) during a CO2 reactivity test to determine their influence on the cerebrovascular (CVR) and ventilatory (HCVR) response in subjects with (PFO+, n = 8) and without (PFO-, n = 7) a patent foramen ovale (PFO). We hypothesized that 1) the Pa-PETCO2 would be greater in hypoxia compared with normoxia, 2) the Pa-PETCO2 would be similar, whereas the PET-PaO2 gradient would be greater in those with a PFO, 3) the HCVR and CVR would be underestimated when plotted against PETCO2 compared with PaCO2, and 4) previously derived prediction algorithms will accurately target PaCO2. PETCO2 was controlled by dynamic end-tidal forcing in steady-state steps of -8, -4, 0, +4, and +8 mmHg from baseline in normoxia and hypoxia. Minute ventilation (V̇E), internal carotid artery blood flow (Q̇ICA), middle cerebral artery blood velocity (MCAv), and temperature corrected end-tidal and arterial blood gases were measured throughout experimentation. HCVR and CVR were calculated using linear regression analysis by indexing V̇E and relative changes in Q̇ICA, and MCAv against PETCO2, predicted PaCO2, and measured PaCO2. The Pa-PETCO2 was similar between hypoxia and normoxia and PFO+ and PFO-. The PET-PaO2 was greater in PFO+ by 2.1 mmHg during normoxia (P = 0.003). HCVR and CVR plotted against PETCO2 underestimated HCVR and CVR indexed against PaCO2 in normoxia and hypoxia. Our PaCO2 prediction equation modestly improved estimates of HCVR and CVR. In summary, care must be taken when indexing reactivity measures to PETCO2 compared with PaCO2.

  3. Imaging of Acute Pancreatitis.

    PubMed

    Thoeni, Ruedi F

    2015-11-01

    Acute pancreatitis is an acute inflammation of the pancreas. Several classification systems have been used in the past but were considered unsatisfactory. A revised Atlanta classification of acute pancreatitis was published that assessed the clinical course and severity of disease; divided acute pancreatitis into interstitial edematous pancreatitis and necrotizing pancreatitis; discerned an early phase (first week) from a late phase (after the first week); and focused on systemic inflammatory response syndrome and organ failure. This article focuses on the revised classification of acute pancreatitis, with emphasis on imaging features, particularly on newly-termed fluid collections and implications for the radiologist.

  4. Acute health effects of accidental chlorine gas exposure

    PubMed Central

    2014-01-01

    Objectives This study was conducted to report the course of an accidental release of chlorine gas that occurred in a factory in Gumi-si, South Korea, on March 5, 2013. We describe the analysis results of 2 patients hospitalized because of chlorine-induced acute health problems, as well as the clinical features of 209 non-hospitalized patients. Methods We analyzed the medical records of the 2 hospitalized patients admitted to the hospital, as well as the medical records and self-report questionnaires of 209 non-hospitalized patients completed during outpatient treatment. Results Immediately after the exposure, the 2 hospitalized patients developed acute asthma-like symptoms such as cough and dyspnea, and showed restrictive and combined pattern ventilatory defects on the pulmonary function test. The case 1 showed asthma-like symptoms over six months and diurnal variability in peak expiratory flow rate was 56.7%. In case 2, his FEV1 after treatment (93%) increased by 25% compared to initial FEV1 (68%). Both cases were diagnosed as chlorine-induced reactive airways dysfunction syndrome (RADS) on the basis of these clinical features. The most frequent chief complaints of the 209 non-hospitalized patients were headache (22.7%), followed by eye irritation (18.2%), nausea (11.2%), and sore throat (10.8%), with asymptomatic patients accounting for 36.5%. The multiple-response analysis of individual symptom revealed headache (42.4%) to be the most frequent symptom, followed by eye irritation (30.5%), sore throat (30.0%), cough (29.6%), nausea (27.6%), and dizziness (27.3%). Conclusions The 2 patients hospitalized after exposure to chlorine gas at the leakage site showed a clinical course corresponding to RADS. All of the 209 non-hospitalized patients only complained of symptoms of the upper airways and mucous membrane irritation. PMID:25852940

  5. Acute cor pulmonale in ARDS: rationale for protecting the right ventricle.

    PubMed

    Repessé, Xavier; Charron, Cyril; Vieillard-Baron, Antoine

    2015-01-01

    The ventilatory strategy for ARDS has been regularly amended over the last 40 years as knowledge of the pathophysiology of ARDS has increased. Initially focused mainly on the lung with the objectives of "opening the lung" and optimizing arterial oxygen saturation, this strategy now also takes into account pulmonary vascular injury and its effects on the right ventricle and on hemodynamics. Hemodynamic devices now available at the bedside, such as echocardiography, allow intensivists to evaluate respiratory settings according to right ventricular tolerance. Here, we review the pathophysiology of pulmonary vascular dysfunction in ARDS, consider the beneficial and deleterious effects of mechanical ventilation, describe the incidence and meaning of acute cor pulmonale based on recent studies in large series of patients, and propose a new, although not strictly validated, approach based on the protection of both the lung and right ventricle. One of our conclusions is that evaluating the right ventricle may help intensivists to assess the balance between recruitment and overdistension induced by the ventilatory strategy. Prone positioning with its beneficial effects on the lung and also on hemodynamics (the right ventricle) is a good illustration of this. Readers should be aware that most of the information given in this article reflects the point of view of the authors. Although based on clinical observations, clinical studies, and well-known pathophysiology, there is no evidence-based medicine to support this clinical commentary. Other approaches may be favored, in which case our article should be read as another attempt to help intensivists to improve management of ARDS. PMID:25560864

  6. Acute cor pulmonale in ARDS: rationale for protecting the right ventricle.

    PubMed

    Repessé, Xavier; Charron, Cyril; Vieillard-Baron, Antoine

    2015-01-01

    The ventilatory strategy for ARDS has been regularly amended over the last 40 years as knowledge of the pathophysiology of ARDS has increased. Initially focused mainly on the lung with the objectives of "opening the lung" and optimizing arterial oxygen saturation, this strategy now also takes into account pulmonary vascular injury and its effects on the right ventricle and on hemodynamics. Hemodynamic devices now available at the bedside, such as echocardiography, allow intensivists to evaluate respiratory settings according to right ventricular tolerance. Here, we review the pathophysiology of pulmonary vascular dysfunction in ARDS, consider the beneficial and deleterious effects of mechanical ventilation, describe the incidence and meaning of acute cor pulmonale based on recent studies in large series of patients, and propose a new, although not strictly validated, approach based on the protection of both the lung and right ventricle. One of our conclusions is that evaluating the right ventricle may help intensivists to assess the balance between recruitment and overdistension induced by the ventilatory strategy. Prone positioning with its beneficial effects on the lung and also on hemodynamics (the right ventricle) is a good illustration of this. Readers should be aware that most of the information given in this article reflects the point of view of the authors. Although based on clinical observations, clinical studies, and well-known pathophysiology, there is no evidence-based medicine to support this clinical commentary. Other approaches may be favored, in which case our article should be read as another attempt to help intensivists to improve management of ARDS.

  7. Noninvasive ventilation for acute respiratory failure: a prospective randomised placebo-controlled trial.

    PubMed

    Thys, F; Roeseler, J; Reynaert, M; Liistro, G; Rodenstein, D O

    2002-09-01

    The aim of the present study was to clarify whether the known effects of noninvasive positive-pressure ventilation (NPPV) in patients with respiratory failure are real or due to placebo effects and whether early application of NPPV in the emergency department leads to rapid improvement of the patients condition and outcome. A prospective randomised placebo-controlled study was conducted in 20 patients with severe acute respiratory failure (ARF) secondary to an acute exacerbation of chronic obstructive pulmonary disease (COPD) or acute pulmonary oedema, not improving under conventional medical therapy and on the edge of intubation. Patients received either conventional medical therapy plus two-level NPPV (hi-level NPPV) or conventional medical therapy plus "placebo" NPPV. The main outcome measures involved the need for endotracheal intubation in the bi-level NPPV arm and in the placebo arm after crossing over to active NPPV. Morbidity, length of stay, mortality and the effect of the ventilatory mode on clinical, arterial-blood gas parameters, and the sternocleidomastoid muscles electromyogram (EMG) activity were also measured. The 10 patients in the active NPPV group rapidly improved and none needed intubation. Placebo NPPV resulted in no change in the clinical condition of patients that continued to worsen and the 10 patients were crossed over to active NPPV. Three patients were intubated. No differences in terms of morbidity, length of stay or mortality between the two groups were observed. Active NPPV (but not placebo NPPV) led to a rapid and significant improvement in the clinical parameters, pH and the carbon dioxide tension in arterial blood and to a decrease in respiratory frequency and sternocleidomastoid EMG activity. Early application of bi-level noninvasive positive-pressure ventilation in patients with severe acute respiratory failure, due to chronic obstructive pulmonary disease and acute pulmonary oedema, leads to a rapid improvement in clinical status

  8. Acute chylous peritonitis due to acute pancreatitis.

    PubMed

    Georgiou, Georgios K; Harissis, Haralampos; Mitsis, Michalis; Batsis, Haralampos; Fatouros, Michalis

    2012-04-28

    We report a case of acute chylous ascites formation presenting as peritonitis (acute chylous peritonitis) in a patient suffering from acute pancreatitis due to hypertriglyceridemia and alcohol abuse. The development of chylous ascites is usually a chronic process mostly involving malignancy, trauma or surgery, and symptoms arise as a result of progressive abdominal distention. However, when accumulation of "chyle" occurs rapidly, the patient may present with signs of peritonitis. Preoperative diagnosis is difficult since the clinical picture usually suggests hollow organ perforation, appendicitis or visceral ischemia. Less than 100 cases of acute chylous peritonitis have been reported. Pancreatitis is a rare cause of chyloperitoneum and in almost all of the cases chylous ascites is discovered some days (or even weeks) after the onset of symptoms of pancreatitis. This is the second case in the literature where the patient presented with acute chylous peritonitis due to acute pancreatitis, and the presence of chyle within the abdominal cavity was discovered simultaneously with the establishment of the diagnosis of pancreatitis. The patient underwent an exploratory laparotomy for suspected perforated duodenal ulcer, since, due to hypertriglyceridemia, serum amylase values appeared within the normal range. Moreover, abdominal computed tomography imaging was not diagnostic for pancreatitis. Following abdominal lavage and drainage, the patient was successfully treated with total parenteral nutrition and octreotide.

  9. Acute chylous peritonitis due to acute pancreatitis

    PubMed Central

    Georgiou, Georgios K; Harissis, Haralampos; Mitsis, Michalis; Batsis, Haralampos; Fatouros, Michalis

    2012-01-01

    We report a case of acute chylous ascites formation presenting as peritonitis (acute chylous peritonitis) in a patient suffering from acute pancreatitis due to hypertriglyceridemia and alcohol abuse. The development of chylous ascites is usually a chronic process mostly involving malignancy, trauma or surgery, and symptoms arise as a result of progressive abdominal distention. However, when accumulation of “chyle” occurs rapidly, the patient may present with signs of peritonitis. Preoperative diagnosis is difficult since the clinical picture usually suggests hollow organ perforation, appendicitis or visceral ischemia. Less than 100 cases of acute chylous peritonitis have been reported. Pancreatitis is a rare cause of chyloperitoneum and in almost all of the cases chylous ascites is discovered some days (or even weeks) after the onset of symptoms of pancreatitis. This is the second case in the literature where the patient presented with acute chylous peritonitis due to acute pancreatitis, and the presence of chyle within the abdominal cavity was discovered simultaneously with the establishment of the diagnosis of pancreatitis. The patient underwent an exploratory laparotomy for suspected perforated duodenal ulcer, since, due to hypertriglyceridemia, serum amylase values appeared within the normal range. Moreover, abdominal computed tomography imaging was not diagnostic for pancreatitis. Following abdominal lavage and drainage, the patient was successfully treated with total parenteral nutrition and octreotide. PMID:22563182

  10. Acute otitis media and acute bacterial sinusitis.

    PubMed

    Wald, Ellen R

    2011-05-01

    Acute otitis media and acute bacterial sinusitis are 2 of the most common indications for antimicrobial agents in children. Together, they are responsible for billions of dollars of health care expenditures. The pathogenesis of the 2 conditions is identical. In the majority of children with each condition, a preceding viral upper respiratory tract infection predisposes to the development of the acute bacterial complication. It has been shown that viral upper respiratory tract infection predisposes to the development of acute otitis media in 37% of cases. Currently, precise microbiologic diagnosis of acute otitis media and acute bacterial sinusitis requires performance of tympanocentesis in the former and sinus aspiration in the latter. The identification of a virus from the nasopharynx in either case does not obviate the need for antimicrobial therapy. Furthermore, nasal and nasopharyngeal swabs are not useful in predicting the results of culture of the middle ear or paranasal sinus. However, it is possible that a combination of information regarding nasopharyngeal colonization with bacteria and infection with specific viruses may inform treatment decisions in the future.

  11. A critical role of acute bronchoconstriction in the mortality associated with high-dose sarin inhalation: effects of epinephrine and oxygen therapies.

    PubMed

    Gundavarapu, Sravanthi; Zhuang, Jianguo; Barrett, Edward G; Xu, Fadi; Russell, Robert G; Sopori, Mohan L

    2014-01-15

    Sarin is an organophosphate nerve agent that is among the most lethal chemical toxins known to mankind. Because of its vaporization properties and ease and low cost of production, sarin is the nerve agent with a strong potential for use by terrorists and rouge nations. The primary route of sarin exposure is through inhalation and, depending on the dose, sarin leads to acute respiratory failure and death. The mechanism(s) of sarin-induced respiratory failure is poorly understood. Sarin irreversibly inhibits acetylcholine esterase, leading to excessive synaptic levels of acetylcholine and, we have previously shown that sarin causes marked ventilatory changes including weakened response to hypoxia. We now show that LD50 sarin inhalation causes severe bronchoconstriction in rats, leading to airway resistance, increased hypoxia-induced factor-1α, and severe lung epithelium injury. Transferring animals into 60% oxygen chambers after sarin exposure improved the survival from about 50% to 75% at 24h; however, many animals died within hours after removal from the oxygen chambers. On the other hand, if LD50 sarin-exposed animals were administered the bronchodilator epinephrine, >90% of the animals survived. Moreover, while both epinephrine and oxygen treatments moderated cardiorespiratory parameters, the proinflammatory cytokine surge, and elevated expression of hypoxia-induced factor-1α, only epinephrine consistently reduced the sarin-induced bronchoconstriction. These data suggest that severe bronchoconstriction is a critical factor in the mortality induced by LD50 sarin inhalation, and epinephrine may limit the ventilatory, inflammatory, and lethal effects of sarin.

  12. Acute mastoiditis--revisited.

    PubMed

    Luntz, M; Keren, G; Nusem, S; Kronenberg, J

    1994-09-01

    The clinical course and causative organisms were studied in 18 patients with acute mastoiditis, 13 of whom (72%) had no previous history of middle ear disease. Their age ranged from 5 months to 21 years, and duration of middle ear symptoms immediately prior to admission ranged from 1 to 45 days (average 9.7 days). None had undergone a myringotomy prior to admission, while 13 (72%) had been receiving antibiotic treatment for acute otitis media. Three were admitted with intracranial complications. Bacteria were isolated in 10 of the 16 patients in whom samples were available for bacterial culture, and included Streptococcus pneumonia (2), Streptococcus pyogenes (2), Staphylococcus aureus (2), Staphlococcus coagulase negative (2), Klebsiella pneumonia (1), and Pseudomonas aeruginosa (1). Of the 17 patients treated by us, 11 received surgery. Acute otitis media, secretory otitis media, acute mastoiditis, subacute mastoiditis and masked mastoiditis create a continuum. Antibiotic treatment for acute otitis media cannot be considered as an absolute safeguard against acute mastoiditis. When antibiotics are prescribed for acute mastoiditis before culture result is available, an anti-staphylococcal agent should be included. At least some patients with acute mastoiditis develop a primary infection of the bony framework of the middle ear cleft. The prevalence of the intracranial complications in acute mastoiditis is still high and may appear soon after or concomitant with the first sign of acute mastioditis.

  13. [Pathogenesis of acute encephalitis and acute encephalopathy].

    PubMed

    Shiomi, Masashi

    2011-03-01

    Many aspects of the pathogenesis of acute encephalitis and acute encephalopathy have been clarified in this decade, although many unknown mechanisms remain to be elucidated. According to progress of MRI and neuroimmunological analysis and the observation of clinical findings, many new syndromes were found, which enhanced our understanding of acute encephalitis and acute encephalopathy. The pathogenesis of encephalitis is divided into infection and immune mediated mechanisms. The antibodies to neuronal surface antigens(NSA) such as NMDA receptors, leucin-rich glioma inactivated 1 (LGI1) and aquaporin 4 were demonstrated in specific encephalitis, limbic encephalitis and neuromyelitis optica. Anti-NSA antibody encephalitis should be treated by immunotherapy such as corticosteroid and plasmapheresis. Acute encephalitis with refractory repetitive partial seizures (AERRPS) is a devastating postinfectious disease in children and adults, although the pathogenesis of AERRPS is poorly understood. Influenza associated encephalopathy(IAE) is characterized by it's high incidence in Japanese children between 1 year and 5 years of age, its onset in the first or the second day of illness and its high mortality (15-30%) and morbidity (25-40%). We proposed the classification of IAE with poor prognosis from the neuroradiological findings. Four types of encephalopathy seem to be differentiated from each other, acute necrotizing encephalopathy (ANE) type, hemorrhagic shock and encephalopathy syndrome (HSES) type, acute brain swelling (ABS) type, febrile convulsive status epilepticus (FCSE) type. The notable radiological features are thalamic lesions in ANE, diffuse cerebral cortical cytotoxic edema in HSES, reversible cerebral swelling in ABS which sometimes reaches lethal brain herniation, and in FCSE type, dendritic high signal in subcortical white matter by DWI ("bright tree appearance") appears simultaneously with the later onset of repetitive focal seizure. These four types are

  14. Acute Vision Loss.

    PubMed

    Bagheri, Nika; Mehta, Sonia

    2015-09-01

    Acute vision loss can be transient (lasting <24 hours) or persistent (lasting >24 hours). When patients present with acute vision loss, it is important to ascertain the duration of vision loss and whether it is a unilateral process affecting one eye or a bilateral process affecting both eyes. This article focuses on causes of acute vision loss in the nontraumatic setting and provides management pearls to help health care providers better triage these patients.

  15. Acute Vision Loss.

    PubMed

    Bagheri, Nika; Mehta, Sonia

    2015-09-01

    Acute vision loss can be transient (lasting <24 hours) or persistent (lasting >24 hours). When patients present with acute vision loss, it is important to ascertain the duration of vision loss and whether it is a unilateral process affecting one eye or a bilateral process affecting both eyes. This article focuses on causes of acute vision loss in the nontraumatic setting and provides management pearls to help health care providers better triage these patients. PMID:26319342

  16. The use of near infrared spectroscopy (NIRS) to determine the ventilatory threshold and the relation between skeletal muscle oxygenation and RPE

    NASA Astrophysics Data System (ADS)

    Tessmer, Kathryn Anne

    This study: (1) compared three (i.e., V-slope, Bhambhani et al., 1997, and Belardinelli et al., 1995) techniques of measuring the ventilatory threshold (VT), (2) examined the relation between OMNI RPE and muscle deoxygenation (MD), and (3) evaluated the impact of gender on MD and RPE. Subjects included 20 males and 13 females, aged 25-29 years. A commercial NIRS sensor (NIRS Micro-Run Man model # MRM-96) was placed over the right vastus lateralis and secured with an elastic wrap. Next, each subject underwent a progressive multistage cycle ergometer test to establish the VT using the V-slope method and NIRS methods. The V-slope (58.62 +/- 10.47% VO2peak), Bhambhani et al. 1997 (49.75 +/- 20.13% VO2peak), and Belardinelli et al. 1995 (60.87 +/- 10.15% VO2peak) methods did not result in different (F(2,49) = 2.77, p > 0.05) VT values. The following significant linear regression equation was generated (p = 0.016): OMNI RPE = 5.97 - (15.20)MD (R = -0.20, R 2 = 0.04, and SE = 2.76). The two-way ANOVA (gender x power output) conducted on OMNI RPE revealed a significant main effect for gender ( F(1,193) = 19.53, p < 0.05). Males had lower RPEs (6.32 +/- .17) than females (7.16 +/- .28). A significant main effect for power output was also found (F(9, 193) = 56.21, p < 0.05). In addition, a significant gender x power output interaction was found ( F(7, 193) = 2.11, p < 0.05). With respect to MD, the two-way ANOVA revealed a significant main effect for gender (F(1, 133) = 10.61, p < 0.05). Females had less MD (0.012 +/- .007) than males (0.002 +/- .005). The results of this study indicate that the three methods of determining the VT were not different. MD values decreased with increasing ratings of perceived exertion. RPE differed between genders, with males having lower RPE's than females (p < 0.05). Also, a significant gender x power output interaction was found (p < 0.05). Finally, women experienced less skeletal MD than men during a progressively incremented cycle

  17. Synthes Award for Resident Research on Brain and Craniofacial Injury: normoxic ventilatory resuscitation after controlled cortical impact reduces peroxynitrite-mediated protein nitration in the hippocampus.

    PubMed

    Ahn, Edward S; Robertson, Courtney L; Vereczki, Viktoria; Hoffman, Gloria E; Fiskum, Gary

    2005-01-01

    Resuscitation with 100% ventilatory oxygen is routinely initiated after severe traumatic brain injury (TBI). Despite the objective to improve oxygenation of the injured brain, there are concerns about the increased production of reactive oxygen species (ROS), which can lead to further neuronal damage. 3-nitrotyrosine (3-NT), the product of peroxynitrite-meditated tyrosine residue nitration, has been used as a marker for ROS-induced oxidative damage to proteins. We hypothesized that posttraumatic resuscitation with hyperoxic ventilation with a fraction of inspired oxygen (Fio2, 100%) results in increased ROS-induced damage to proteins compared with resuscitation with normoxic ventilation or room air (Fio2, 21%). Male Sprague-Dawley rats underwent controlled cortical impact (CCI) and were resuscitated with either normoxic or hyperoxic ventilation for 1 hour after injury (n = 5 per group). Sham-operated control groups received 1 hour of normoxic or hyperoxic ventilation without CCI (n = 4-5 per group). Twenty-four hours after injury, rats were perfused with fixative, and hippocampi were evaluated for levels of 3-NT immunostaining. In a second experiment, for a delayed assessment of neuronal survival, another set of rats similarly underwent CCI and normoxic or hyperoxic ventilation for 1 hour (n = 4 per group), and a sham-operated group was used as a control (n = 4). One week after injury, neuronal cell counts and abnormal cell quantification were performed after staining with the neuron-specific NeuN antibody. Quantification of 3-NT staining revealed significantly increased levels in the ipsilateral hippocampus in the hyperoxic CCI group. The normoxic group showed a 51.0% reduction of staining in CA1 when compared with those rats resuscitated with hyperoxia and a 50.8% reduction in CA3 (both P < 0.05). There was no significant difference in staining between the injured normoxic group and the sham-operated groups. In the delayed analysis of neuronal survival, although

  18. [Acute mastoiditis in children].

    PubMed

    Kajosaari, Lauri; Sinkkonen, Saku T; Laulajainen-Hongisto, Anu; Jero, Jussi

    2014-01-01

    Acute mastoiditis in children develops when acute otitis media (AOM) spreads into the mastoid air cells inside the temporal bone. The diagnosis is based on clinical findings of AOM with simultaneous signs of infection in the mastoid area. The most common pathogen causing acute mastoiditis in children is Streptococcus pneumoniae. Intravenous antimicrobial medication, tympanostomy and microbial sample are the cornerstones of the treatment. If a complication of mastoiditis is suspected, imaging studies are needed, preferably with magnetic resonance imaging. The most common complication of acute mastoiditis is a subperiosteal abscess. PMID:24660384

  19. Role of tachykinins in ozone-induced acute lung injury in guinea pigs

    SciTech Connect

    Tepper, J.S.; Costa, D.L.; Fitzgerald, S.; Doerfler, D.L.; Bromberg, P.A. )

    1993-09-01

    To examine the hypothesis that the acute reversible changes caused by ozone (O3) exposure are mediated by tachykinin release, guinea pigs were depleted of tachykinins by use of repeated capsaicin (CAP) injections before O3 exposure in an attempt to prevent O3-induced functional changes. Unexpectedly, CAP pretreatment caused divergent results in the functional responses to O3. Ventilatory measurements obtained from CAP-pretreated O3-exposed (CAP-O3) animals were exacerbated rather than diminished compared with the effects of O3 alone. Similarly, lavage fluid protein accumulation was enhanced in the CAP-O3 group compared with the O3-exposed group. In better agreement with our initial hypothesis, the CAP-O3 group was less responsive than the O3-exposed animals to histamine aerosol challenge. Additionally, Evans blue dye accumulation, a hallmark of tachykinin release, was increased in O3-exposed animals and was partially blocked in the CAP-O3 group. These data suggest that tachykinin-containing sensory fibers are unlikely to mediate the acute effects of O3 exposure on tidal breathing and lavage fluid protein accumulation but may play a role in causing post-O3 airway hyperreactivity and protein extravasation into the trachea.

  20. Effects of dead space loading on neuro-muscular and neuro-ventilatory coupling of the respiratory system during exercise in healthy adults: implications for dyspnea and exercise tolerance.

    PubMed

    Jensen, Dennis; O'Donnell, Denis E; Li, Ruifa; Luo, Yuan-Ming

    2011-12-15

    We examined the effects of dead space loading (DSL) on ventilation (V˙E), neural respiratory drive (EMGdi%max, diaphragm EMG expressed as a % of maximal EMGdi), contractile respiratory muscle effort (Pes,tidal%P(Imax), tidal esophageal pressure swing expressed as a % of maximal inspiratory Pes) and exertional dyspnea intensity ratings in 11 healthy adults with normal spirometry. Subjects completed, in random order, symptom-limited incremental cycle exercise tests under control (CTRL) and DSL (500 ml) conditions. Compared with CTRL, DSL decreased exercise tolerance by 20-25%; increased exertional dyspnea intensity ratings in direct proportion to concurrent increases in EMGdi%max, Pes,tidal%P(Imax) and V˙E; and had little/no effect on the inter-relationships between EMGdi%max, Pes,tidal%P(Imax) and V˙E during exercise. In conclusion, DSL was associated with an earlier onset of intolerable dyspnea; however, neuro-muscular and neuro-ventilatory coupling of the respiratory system remained relatively preserved during exercise in the presence of an increased external dead space. Under these circumstances, DSL-induced increases in exertional dyspnea intensity ratings reflected, at least in part, the awareness of increased neural respiratory drive, contractile respiratory muscle effort and ventilatory output.

  1. Naloxone application to the ventrolateral medulla enhances the respiratory response to inspired carbon dioxide

    SciTech Connect

    Trouth, C.O.; Bada, F.J.; Pan, Yi; Holloway, J.A.; Millis, R.M.; Bernard, D.G. )

    1991-01-01

    Previous studies have shown that systemic administration of the opiate antagonist naloxone potentiates the ventilatory response to inspired carbon dioxide. The present study was designed to localize the site of action of naloxone for increasing the respiratory chemosensitivity to inhaled carbon dioxide (CO{sub 2}) in cats. Naloxone applied topically to the caudal chemosensitive area on the ventral medullary surface (VMS) during hypercapnic breathing produced a 75% greater increase in minute ventilation than hypercapnic breathing alone. Furthermore, hypercapnic breathing produced a 200% increase in neuronal activity of VMS chemosensitive cells; this was further increased 120% by naloxone. It is concluded that naloxone increases the sensitivity of neurons in the caudal respiratory chemosensitive area of cats to hypercapnia, and that endogenous opiates may act as modulators at VMS chemosensitive sites during hypercapnic breathing.

  2. Spontaneous Rectus Sheath Hematoma in Pregnancy Complicated by the Development of Transfusion Related Acute Lung Injury: A Case Report and Review of the Literature

    PubMed Central

    Gibbs, Jennifer; Bridges, Firas; Trivedi, Kiran; Vullo, John

    2016-01-01

    Background Rectus sheath hematoma (RSH) represents a rare, but serious cause of abdominal pain. Case Here we discuss the case of a healthy multigravida female who presented at 28 weeks gestation with spontaneous RSH. Conservative management with multiple blood transfusions led to the development of transfusion related acute lung injury (TRALI) and intensive care unit admission. She was managed with noninvasive ventilatory support, gradually improved, and was weaned of ventilation. After hospital discharge, she progressed to full term and delivered a viable male infant vaginally at 37 weeks gestation. Conclusion Review of the literature demonstrates 13 cases of RSH in pregnancy, including our own. No other cases were complicated by transfusion related morbidity. RSH and TRALI are rare, but life threatening entities that can complicate pregnancy. PMID:27651980

  3. Acute disseminated encephalomyelitis (ADEM) following a H3N3 parainfluenza virus infection in a pregnant asthmatic woman with respiratory failure.

    PubMed

    Zeb, Qaiser; Alegria, Ana

    2014-01-01

    This case report relates to a 31-year-old pregnant woman, asthmatic, admitted to the intensive care unit with respiratory failure, secondary to a viral community-acquired pneumonia. A type 3 (H3N3) parainfluenza virus RNA was isolated in her throat swab. The patient developed neurological symptoms (behavioural changes, irritability, agitation and impaired consciousness) while being weaned off sedation and ventilatory support. Cerebrospinal fluid was clear with an opening pressure of 26 cm H2O. Brain MRI showed features compatible with acute disseminated encephalomyelitis. Immune screen and EEG were normal. She was treated with intravenous methylprednisolone followed by oral prednisolone. The patient made an almost full neurological recovery within 4 weeks after starting on steroids. The patient delivered a healthy baby at 38 weeks gestation. This case highlights the importance to keep in mind rare conditions that need early recognition and prompt treatment. Brain MRI is the key to early diagnosis and treatment. PMID:25281245

  4. Acute disseminated encephalomyelitis (ADEM) following a H3N3 parainfluenza virus infection in a pregnant asthmatic woman with respiratory failure.

    PubMed

    Zeb, Qaiser; Alegria, Ana

    2014-01-01

    This case report relates to a 31-year-old pregnant woman, asthmatic, admitted to the intensive care unit with respiratory failure, secondary to a viral community-acquired pneumonia. A type 3 (H3N3) parainfluenza virus RNA was isolated in her throat swab. The patient developed neurological symptoms (behavioural changes, irritability, agitation and impaired consciousness) while being weaned off sedation and ventilatory support. Cerebrospinal fluid was clear with an opening pressure of 26 cm H2O. Brain MRI showed features compatible with acute disseminated encephalomyelitis. Immune screen and EEG were normal. She was treated with intravenous methylprednisolone followed by oral prednisolone. The patient made an almost full neurological recovery within 4 weeks after starting on steroids. The patient delivered a healthy baby at 38 weeks gestation. This case highlights the importance to keep in mind rare conditions that need early recognition and prompt treatment. Brain MRI is the key to early diagnosis and treatment.

  5. Acute Hepatic Porphyria

    PubMed Central

    Bissell, D. Montgomery; Wang, Bruce

    2015-01-01

    The porphyrias comprise a set of diseases, each representing an individual defect in one of the eight enzymes mediating the pathway of heme synthesis. The diseases are genetically distinct but have in common the overproduction of heme precursors. In the case of the acute (neurologic) porphyrias, the cause of symptoms appears to be overproduction of a neurotoxic precursor. For the cutaneous porphyrias, it is photosensitizing porphyrins. Some types have both acute and cutaneous manifestations. The clinical presentation of acute porphyria consists of abdominal pain, nausea, and occasionally seizures. Only a small minority of those who carry a mutation for acute porphyria have pain attacks. The triggers for an acute attack encompass certain medications and severely decreased caloric intake. The propensity of females to acute attacks has been linked to internal changes in ovarian physiology. Symptoms are accompanied by large increases in delta-aminolevulinic acid and porphobilinogen in plasma and urine. Treatment of an acute attack centers initially on pain relief and elimination of inducing factors such as medications; glucose is administered to reverse the fasting state. The only specific treatment is administration of intravenous hemin. An important goal of treatment is preventing progression of the symptoms to a neurological crisis. Patients who progress despite hemin administration have undergone liver transplantation with complete resolution of symptoms. A current issue is the unavailability of a rapid test for urine porphobilinogen in the urgent-care setting. PMID:26357631

  6. Uncomplicated acute bronchitis.

    PubMed

    Gonzales, R; Sande, M A

    2000-12-19

    Acute bronchitis is an acute cough illness in otherwise healthy adults that usually lasts 1 to 3 weeks. This review describes the pathophysiology of the condition and provides a practical approach to the evaluation and treatment of adults with uncomplicated acute bronchitis. Practical points to be made are:1. Respiratory viruses appear to cause the large majority of cases of uncomplicated acute bronchitis.2. Pertussis infection is present in up to 10% to 20% of adults with cough illness of more than 2 to 3 weeks' duration. No clinical features distinguish pertussis from nonpertussis infection in adults who were immunized against pertussis as children.3. Transient bronchial hyperresponsiveness appears to be the predominant mechanism of the bothersome cough of acute bronchitis.4. Ruling out pneumonia is the primary objective in evaluating adults with acute cough illness in whom comorbid conditions and occult asthma are absent or unlikely. In the absence of abnormalities in vital signs (heart rate > 100 beats/min, respiratory rate > 24 breaths/min, and oral body temperature > 38 degrees C), the likelihood of pneumonia is very low.5. Randomized, placebo-controlled trials do not support routine antibiotic treatment of uncomplicated acute bronchitis.6. Randomized, placebo-controlled trials have shown that inhaled albuterol decreases the duration of cough in adults with uncomplicated acute bronchitis.7. Intervention studies suggest that antibiotic treatment of acute bronchitis can be reduced by using a combination of patient and physician education. Decreased rates of antibiotic treatment are not associated with increased utilization, return visits, or dissatisfaction with care.

  7. [Severe acute respiratory syndrome: a global overview of the epidemic].

    PubMed

    Franco-Paredes, Carlos; Kuri-Morales, Pablo; Alvarez-Lucas, Carlos; Palacios-Zavala, Ethel; Nava-Frías, Margarita; Betancourt-Cravioto, Miguel; Santos-Preciado, José Ignacio; Tapia-Conyer, Roberto

    2003-01-01

    In early February 2003, the World Health Organization (WHO) began receiving reports of patients with a syndrome characterized by an atypical pneumonia with rapid progression to respiratory failure without an identified cause despite extensive diagnostic workups. Most of these reports pointed out that the outbreak started in Southern China, specifically in the Guandong Province. The initial outbreak in South East Asia has already spread to other Regions in Asia, Europe, North and South America, and South Africa. Many of these cases can be linked through chains of transmission to an index case from the Guandong Province who visited Hong Kong. Although the exact mode of transmission has not been clearly established, the etiology of this syndrome has already been identified. A novel Coronavirus has been identified by electron microscopy and molecular assays in multiple laboratories from respiratory specimens throughout the world. The syndrome has been defined as SARS (Severe Acute Respiratory Syndrome) by WHO, and is characterized by an incubation period between 1 and 10 days (average 5 days) and by a febrile phase that usually lasts approximately 3 days. During the respiratory phase that begins around day 3, patients start developing a dry cough, shortness of breath and hypoxemia. Mechanical ventilatory support is required in about 10 to 40% of cases and the case-fatality rate ranges between 3 and 16%. The laboratory findings in SARS cases include leukopenia, thrombocytopenia, and a rise in transaminases and lactic dehydrogenase levels. Treatment of SARS includes supportive measures and the empiric use of ribavirin. Respiratory isolation, use of respiratory masks, and compulsory hand hygiene constitute the principal preventive measures. The confirmation of a case can be performed at reference laboratories by serologic and molecular assays. From the onset of this epidemic Mexico established a surveillance system as well as clinical guidelines and recommendations for

  8. Acute mesenteric ischemia.

    PubMed

    Sise, Michael J

    2014-02-01

    Acute mesenteric ischemia is uncommon and always occurs in the setting of preexisting comorbidities. Mortality rates remain high. The 4 major types of acute mesenteric ischemia are acute superior mesenteric artery thromboembolic occlusion, mesenteric arterial thrombosis, mesenteric venous thrombosis, and nonocclusive mesenteric ischemia, including ischemic colitis. Delays in diagnosis are common and associated with high rates of morbidity and mortality. Prompt diagnosis requires attention to history and physical examination, a high index of suspicion, and early contract CT scanning. Selective use of nonoperative therapy has an important role in nonocclusive mesenteric ischemia of the small bowel and colon.

  9. Respiratory muscle strength and muscle endurance are not affected by acute metabolic acidemia.

    PubMed

    Nizet, Tessa A C; Heijdra, Yvonne F; van den Elshout, Frank J J; van de Ven, Marjo J T; Bosch, Frank H; Mulder, Paul H; Folgering, Hans Th M

    2009-11-01

    Respiratory muscle fatigue in asthma and chronic obstructive lung disease (COPD) contributes to respiratory failure with hypercapnia, and subsequent respiratory acidosis. Therapeutic induction of acute metabolic acidosis further increases the respiratory drive and, therefore, may diminish ventilatory failure and hypercapnia. On the other hand, it is known that acute metabolic acidosis can also negatively affect (respiratory) muscle function and, therefore, could lead to a deterioration of respiratory failure. Moreover, we reasoned that the impact of metabolic acidosis on respiratory muscle strength and respiratory muscle endurance could be more pronounced in COPD patients as compared to asthma patients and healthy subjects, due to already impaired respiratory muscle function. In this study, the effect of metabolic acidosis was studied on peripheral muscle strength, peripheral muscle endurance, airway resistance, and on arterial carbon dioxide tension (PaCO(2)). Acute metabolic acidosis was induced by administration of ammonium chloride (NH(4)Cl). The effect of metabolic acidosis was studied on inspiratory and expiratory muscle strength and on respiratory muscle endurance. Effects were studied in a randomized, placebo-controlled cross-over design in 15 healthy subjects (4 male; age 33.2 +/- 11.5 years; FEV(1) 108.3 +/- 16.2% predicted), 14 asthma patients (5 male; age 48.1 +/- 16.1 years; FEV(1) 101.6 +/- 15.3% predicted), and 15 moderate to severe COPD patients (9 male; age 62.8 +/- 6.8 years; FEV(1) 50.0 +/- 11.8% predicted). An acute metabolic acidemia of BE -3.1 mmol x L(-1) was induced. Acute metabolic acidemia did not significantly affect strength or endurance of respiratory and peripheral muscles, respectively. In all subjects airway resistance was significantly decreased after induction of metabolic acidemia (mean difference -0.1 kPa x sec x L(-1) [95%-CI: -0.1 - -0.02]. In COPD patients PaCO(2) was significantly lowered during metabolic acidemia (mean

  10. Down regulation of Kv3.4 channels by chronic hypoxia increases acute oxygen sensitivity in rabbit carotid body

    PubMed Central

    Kääb, Stefan; Miguel-Velado, Eduardo; López-López, José Ramón; Pérez-García, M Teresa

    2005-01-01

    The carotid body (CB) chemoreceptors participate in the ventilatory responses to acute and chronic hypoxia (CH). Arterial hypoxaemia increases breathing within seconds, and CB chemoreceptors are the principal contributors to this reflex hyperventilatory response. Acute hypoxia induces depolarization of CB chemoreceptors by inhibiting certain K+ channels, but the role of these channels in CH, as in high-altitude acclimatization, is less known. Here we explored the effects of prolonged (24–48 h) hypoxic exposure of rabbit CB chemoreceptor cells in primary cultures on the voltage-dependent K+ currents and on their response to acute hypoxia. We found that CH induces a decrease in the amplitude of outward K+ currents due to a reduction in a fast-inactivating BDS- and highly TEA-sensitive component of the current. In spite of this effect, acute hypoxic inhibition of K+ currents is increased in CH cultures, as well as hypoxia-induced depolarization. These data suggest that downregulation of this component (that does not contribute to the oxygen-sensitive K+ current (IKO2)) participates in the hypoxic sensitization. Pharmacological, immunocytochemical and quantitative PCR (qPCR) experiments demonstrate that CH-induced decrease in outward K+ currents is due to a downregulation of the expression of Kv3.4 channels. Taken together, our results suggest that CH sensitization in rabbit CB could be achieved by an increase in the relative contribution of IKO2 to the outward K+ current as a consequence of the decreased expression of the oxygen-insensitive component of the current. We conclude that acute and chronic hypoxia can exert their effects acting on different molecular targets. PMID:15890707

  11. Acute genital ulcers

    PubMed Central

    Delgado-García, Silvia; Palacios-Marqués, Ana; Martínez-Escoriza, Juan Carlos; Martín-Bayón, Tina-Aurora

    2014-01-01

    Acute genital ulcers, also known as acute vulvar ulcers, ulcus vulvae acutum or Lipschütz ulcers, refer to an ulceration of the vulva or lower vagina of non-venereal origin that usually presents in young women, predominantly virgins. Although its incidence is unknown, it seems a rare entity, with few cases reported in the literature. Their aetiology and pathogenesis are still unknown. The disease is characterised by an acute onset of flu-like symptoms with single or multiple painful ulcers on the vulva. Diagnosis is mainly clinical, after exclusion of other causes of vulvar ulcers. The treatment is mainly symptomatic, with spontaneous resolution in 2 weeks and without recurrences in most cases. We present a case report of a 13-year-old girl with two episodes of acute ulcers that fit the clinical criteria for Lipschütz ulcers. PMID:24473429

  12. Acute Pancreatitis and Pregnancy

    MedlinePlus

    ... sudden inflammation of the pancreas manifested clinically by abdominal pain, nausea and dehydration that is usually self-limiting ... room for evaluation should they develop any abnormal abdominal pain symptoms. Conclusions While a rare event, acute pancreatitis ...

  13. Ear infection - acute

    MedlinePlus

    ... Risk factors for acute ear infections include: Attending day care (especially centers with more than 6 children) Changes ... hands and toys often. If possible, choose a day care that has 6 or fewer children. This can ...

  14. Treatment of acute gout.

    PubMed

    Schlesinger, Naomi

    2014-05-01

    This article presents an overview of the treatment of acute gout. Nonpharmacologic and pharmacologic treatments, monotherapy versus combination therapy, suggested recommendations, guidelines for treatment, and drugs under development are discussed.

  15. Acute interstitial pneumonia.

    PubMed

    Bouros, D; Nicholson, A C; Polychronopoulos, V; du Bois, R M

    2000-02-01

    The term "acute interstitial pneumonia" (AIP) describes an idiopathic clinicopathological condition, characterized clinically by an interstitial lung disease causing rapid onset of respiratory failure, which is distinguishable from the other more chronic forms of interstitial pneumonia. It is synonymous with Hamman-Rich syndrome, occurring in patients without pre-existing lung disease. The histopathological findings are those of diffuse alveolar damage. AIP radiologically and physiologically resembles acute respiratory distress syndrome (ARDS) and is considered to represent the small subset of patients with idiopathic ARDS. It is frequently confused with other clinical entities characterized by rapidly progressive interstitial pneumonia, especially secondary acute interstitial pneumonia, acute exacerbations and accelerated forms of cryptogenic fibrosing alveolitis . Furthermore, many authors use the above terms, both erroneously and interchangeably. It has a grave prognosis with >70% mortality in 3 months, despite mechanical ventilation. This review aims to clarify the relative clinical and pathological issues and terminology.

  16. Acute mountain sickness

    MedlinePlus

    High altitude cerebral edema; Altitude anoxia; Altitude sickness; Mountain sickness; High altitude pulmonary edema ... Acute mountain sickness is caused by reduced air pressure and lower oxygen levels at high altitudes. The faster you ...

  17. Acute genital ulcers.

    PubMed

    Delgado-García, Silvia; Palacios-Marqués, Ana; Martínez-Escoriza, Juan Carlos; Martín-Bayón, Tina-Aurora

    2014-01-28

    Acute genital ulcers, also known as acute vulvar ulcers, ulcus vulvae acutum or Lipschütz ulcers, refer to an ulceration of the vulva or lower vagina of non-venereal origin that usually presents in young women, predominantly virgins. Although its incidence is unknown, it seems a rare entity, with few cases reported in the literature. Their aetiology and pathogenesis are still unknown. The disease is characterised by an acute onset of flu-like symptoms with single or multiple painful ulcers on the vulva. Diagnosis is mainly clinical, after exclusion of other causes of vulvar ulcers. The treatment is mainly symptomatic, with spontaneous resolution in 2 weeks and without recurrences in most cases. We present a case report of a 13-year-old girl with two episodes of acute ulcers that fit the clinical criteria for Lipschütz ulcers.

  18. Weight Loss & Acute Porphyria

    MedlinePlus

    ... Sale You are here Home Diet and Nutrition Weight loss & acute Porphyria Being overweight is a particular problem ... one of these diseases before they enter a weight-loss program. Also, they should not participate in a ...

  19. Acute Radiation Syndrome

    MedlinePlus

    ... Dictionary Radiation Emergencies & Your Health Possible Health Effects Contamination and Exposure Acute Radiation Syndrome (ARS) Cutaneous Radiation ... Decision Making in Radiation Emergencies Protective Actions Internal Contamination Clinical Reference (ICCR) Application Psychological First Aid in ...

  20. The potential role and limitations of echocardiography in acute respiratory distress syndrome.

    PubMed

    Lazzeri, Chiara; Cianchi, Giovanni; Bonizzoli, Manuela; Batacchi, Stefano; Peris, Adriano; Gensini, Gian Franco

    2016-04-01

    Bedside use of Doppler echocardiography is being featured as a promising, clinically useful tool in assessing the pulmonary circulation in patients with acute respiratory distress syndrome (ARDS). The present review is aimed at summarizing the available evidence obtained with echocardiography on right ventricle (RV) function and pulmonary circulation in ARDS and to highlight the potential of this technique in clinical practice (only articles in English language were considered). According to the available evidence on echocardiographic findings, the following conclusions can be drawn: (a) echocardiography (transthoracic and transesophageal) has a growing role in the management ARDS patients mainly because of the strict interactions between the lung (and ventilation) and the RV and pulmonary circulation; (b) there may be a continuum of alterations in RV size and function and pulmonary circulation which may end in the development of acute cor pulmonale, probably paralleling ARDS disease severity; and (c) the detection of acute cor pulmonale should prompt intensivists to tailor their ventilatory strategy to the individual patient depending on the echocardiography findings. Bearing in mind the clinical role and growing importance of echocardiography in ARDS and the available evidence on this topic, we present a flow chart including the parameters to be measured and the timing of echo exams in ARDS patients. Despite the important progress that echocardiography has gained in the evaluation of patients with ARDS, several open questions remain and echocardiography still appears to be underused in these patients. A more systematic use of echocardiography (mainly through shared protocols) in ARDS could help intensivists to tailor the optimal treatment in individual patients as well as highlighting the limits and potential of this methodology in patients with ALI. PMID:26660667

  1. Differentiating Acute Otitis Media and Acute Mastoiditis in Hospitalized Children.

    PubMed

    Laulajainen-Hongisto, Anu; Aarnisalo, Antti A; Jero, Jussi

    2016-10-01

    Acute otitis media is a common infection in children. Most acute otitis media episodes can be treated at an outpatient setting with antimicrobials, or only expectant observation. Hospital treatment with parenteral medication, and myringotomy or tympanostomy, may be needed to treat those with severe, prolonged symptoms, or with complications. The most common intratemporal complication of acute otitis media is acute mastoiditis. If a child with acute mastoiditis does not respond to this treatment, or if complications develop, further examinations and other surgical procedures, including mastoidectomy, are considered. Since the treatment of complicated acute otitis media and complicated acute mastoiditis differs, it is important to differentiate these two conditions. This article focuses on the differential diagnostics of acute otitis media and acute mastoiditis in children. PMID:27613655

  2. Differentiating Acute Otitis Media and Acute Mastoiditis in Hospitalized Children.

    PubMed

    Laulajainen-Hongisto, Anu; Aarnisalo, Antti A; Jero, Jussi

    2016-10-01

    Acute otitis media is a common infection in children. Most acute otitis media episodes can be treated at an outpatient setting with antimicrobials, or only expectant observation. Hospital treatment with parenteral medication, and myringotomy or tympanostomy, may be needed to treat those with severe, prolonged symptoms, or with complications. The most common intratemporal complication of acute otitis media is acute mastoiditis. If a child with acute mastoiditis does not respond to this treatment, or if complications develop, further examinations and other surgical procedures, including mastoidectomy, are considered. Since the treatment of complicated acute otitis media and complicated acute mastoiditis differs, it is important to differentiate these two conditions. This article focuses on the differential diagnostics of acute otitis media and acute mastoiditis in children.

  3. Flavopiridol, Cytarabine, and Mitoxantrone in Treating Patients With Acute Leukemia

    ClinicalTrials.gov

    2013-10-07

    Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Adult Acute Myeloid Leukemia; Secondary Acute Myeloid Leukemia; Untreated Adult Acute Lymphoblastic Leukemia; Untreated Adult Acute Myeloid Leukemia

  4. Thrombosis and acute leukemia.

    PubMed

    Crespo-Solís, Erick

    2012-04-01

    Thrombosis is a common complication in patients with acute leukemia. While the presence of central venous lines, concomitant steroids, the use of Escherichia coli asparaginase and hereditary thrombophilic abnormalities are known risk factors for thrombosis in children, information on the pathogenesis, risk factors, and clinical outcome of thrombosis in adult patients with acute lymphoid leukemia (ALL) or acute myeloid leukemia (AML) is still scarce. Expert consensus and guidelines regarding leukemia-specific risk factors, thrombosis prevention, and treatment strategies, as well as optimal type of central venous catheter in acute leukemia patients are required. It is likely that each subtype of acute leukemia represents a different setting for the development of thrombosis and the risk of bleeding. This is perhaps due to a combination of different disease-specific pathogenic mechanisms of thrombosis, including the type of chemotherapy protocol chosen, the underlying patients health, associated risk factors, as well as the biology of the disease itself. The risk of thrombosis may also vary according to ethnicity and prevalence of hereditary risk factors for thrombosis; thus, it is advisable for Latin American, Asian, and African countries to report on their specific patient population. PMID:22507812

  5. Acute Appendicitis Secondary to Acute Promyelocytic Leukemia

    PubMed Central

    Rodriguez, Eduardo A.; Lopez, Marvin A.; Valluri, Kartik; Wang, Danlu; Fischer, Andrew; Perdomo, Tatiana

    2015-01-01

    Patient: Female, 43 Final Diagnosis: Myeloid sarcoma appendicitis Symptoms: Abdominal pain • chills • fever Medication: — Clinical Procedure: Laparoscopic appendectomy, bone marrow biopsy Specialty: Gastroenterology and Hepatology Objective: Rare disease Background: The gastrointestinal tract is a rare site for extramedullary involvement in acute promyelocytic leukemia (APL). Case Report: A 43-year-old female with no past medical history presented complaining of mild abdominal pain, fever, and chills for the past day. On examination, she was tachycardic and febrile, with mild tenderness of her right lower quadrant and without signs of peritoneal irritation. Laboratory examination revealed pancytopenia and DIC, with a fibrinogen level of 290 mg/dL. CT of the abdomen showed a thickened and hyperemic appendix without perforation or abscess, compatible with acute appendicitis. The patient was given IV broad-spectrum antibiotics and was transfused with packed red blood cells and platelets. She underwent uncomplicated laparoscopic appendectomy and bone marrow biopsy, which revealed neo-plastic cells of 90% of the total bone marrow cellularity. Flow cytometry indicated presence of 92.4% of immature myeloid cells with t (15: 17) and q (22: 12) mutations, and FISH analysis for PML-RARA demonstrated a long-form fusion transcript, positive for APL. Appendix pathology described leukemic infiltration with co-expression of myeloperoxidase and CD68, consistent with myeloid sarcoma of the appendix. The patient completed a course of daunorubicin, cytarabine, and all trans-retinoic acid. Repeat bone marrow biopsy demonstrated complete remission. She will follow up with her primary care physician and hematologist/oncologist. Conclusions: Myeloid sarcoma of the appendix in the setting of APL is very rare and it might play a role in the development of acute appendicitis. Urgent management, including bone marrow biopsy for definitive diagnosis and urgent surgical intervention

  6. The impact of recurrent acute chest syndrome on the lung function of young adults with sickle cell disease.

    PubMed

    Knight-Madden, Jennifer M; Forrester, Terrence S; Lewis, Norma A; Greenough, Anne

    2010-12-01

    The aim of this study was to assess the impact of recurrent acute chest syndrome (ACS) episodes on the lung function of young adults with sickle cell disease (SCD). Our prospective study included 80 SCD adults [26 with recurrent acute chest syndrome (ACS)] and 80 ethnically matched controls aged between 18 and 28 years. Lung function (spirometry and lung volumes) was measured and the results were expressed as the percentage predicted for height. Bronchial hyperresponsiveness (BHR) was assessed by the response to either a bronchodilator or an exercise challenge. The adults with recurrent ACS (two or more ACS episodes) had lower median forced vital capacity (74 vs. 83%, p = 0.03), forced expiratory volume in 1 s (79 vs. 90%, p < 0.03), and total lung capacity (69 vs. 81%, p = 0.04) than SCD adults who had one or no ACS episodes. The greater the number of ACS episodes, the greater the reduction in lung function (p = 0.001). The adults with SCD had lower median forced vital capacity (81 vs. 106%), forced expiratory volume in 1 s (85 vs. 107%), and total lung capacity (80 vs. 87%) than the controls (p < 0.001). Similar numbers in each group had BHR (p = 0.2). The prevalence of restrictive ventilatory defect in the patients with SCD was almost double that of the controls (p = 0.004). Young adults with SCD have worse lung function than ethnically matched controls, particularly if they have suffered recurrent ACS episodes.

  7. [Acute pancreatitis in children].

    PubMed

    Rottier, B L; Holl, R A; Draaisma, J M

    1998-02-21

    Acute pancreatitis is probably commoner in children than was previously thought. In children it is most commonly associated with trauma or viral infection. The presentation may be subtler than in adults, requiring a high index of suspicion in the clinician. In three children, two boys aged 4 and 10 and a girl of 15 years, acute pancreatitis was suspected because of the findings at ultrasonography and endoscopic retrograde cholangiopancreatography performed when the disease recurred (the boy aged 4), apathy and immobility without dehydration or other obvious causes (the boy aged 10), and severe abdominal pain in combination with vomiting (the girl). All three patients had severely increased (urinary) amylase levels. Most often, acute pancreatitis in children tends to be a self-limiting disease which responds well to conservative treatment.

  8. EXPERIMENTAL ACUTE GLOMERULITIS

    PubMed Central

    Lukens, Francis D. W.; Longcope, Warfield T.

    1931-01-01

    1. Both focal and diffuse glomerulitis has been produced in rabbits by the injection directly into the left renal artery of suspensions of heat killed hemolytic streptococci. 2. Similar lesions in the glomeruli could not be obtained by the injection of suspensions of bismuth oxychloride into the left renal artery of normal rabbits. 3. The acute glomerulitis occurred in only about one-half of the rabbits employed for the experiments. 4. Glomerulitis was observed much more frequently in rabbits in which an acute localized streptococcus infection had been produced by the intracutaneous injection of living hemolytic streptococci, than in normal rabbits. The occurrence of acute glomerulitis was usually associated with a well marked skin reaction to the filtrates of hemolytic streptococci. PMID:19869861

  9. Acute Decompensated Heart Failure

    PubMed Central

    Joseph, Susan M.; Cedars, Ari M.; Ewald, Gregory A.; Geltman, Edward M.; Mann, Douglas L.

    2009-01-01

    Hospitalizations for acute decompensated heart failure are increasing in the United States. Moreover, the prevalence of heart failure is increasing consequent to an increased number of older individuals, as well as to improvement in therapies for coronary artery disease and sudden cardiac death that have enabled patients to live longer with cardiovascular disease. The main treatment goals in the hospitalized patient with heart failure are to restore euvolemia and to minimize adverse events. Common in-hospital treatments include intravenous diuretics, vasodilators, and inotropic agents. Novel pharmaceutical agents have shown promise in the treatment of acute decompensated heart failure and may simplify the treatment and reduce the morbidity associated with the disease. This review summarizes the contemporary management of patients with acute decompensated heart failure. PMID:20069075

  10. Acute asthma during pregnancy.

    PubMed Central

    Stenius-Aarniala, B. S.; Hedman, J.; Teramo, K. A.

    1996-01-01

    BACKGROUND: Acute asthma during pregnancy is potentially dangerous to the fetus. The aim of this study was to investigate the effect of an acute attack of asthma during pregnancy on the course of pregnancy or delivery, or the health of the newborn infant, and to identify undertreatment as a possible cause of the exacerbations. METHODS: Five hundred and four pregnant asthmatic subjects were prospectively followed and treated. The data on 47 patients with an attack of asthma during pregnancy were compared with those of 457 asthmatics with no recorded acute exacerbation and with 237 healthy parturients. RESULTS: Of 504 asthmatics, 177 patients were not initially treated with inhaled corticosteroids. Of these, 17% had an acute attack compared with only 4% of the 257 patients who had been on inhaled anti-inflammatory treatment from the start of pregnancy. There were no differences between the groups as to length of gestation, length of the third stage of labour, or amount of haemorrhage after delivery. No differences were observed between pregnancies with and without an exacerbation with regard to relative birth weight, incidence of malformations, hypoglycaemia, or need for phototherapy for jaundice during the neonatal period. CONCLUSIONS: Patients with inadequate inhaled anti-inflammatory treatment during pregnancy run a higher risk of suffering an acute attack of asthma than those treated with an anti-inflammatory agent. However, if the acute attack of asthma is relatively mild and promptly treated, it does not have a serious effect on the pregnancy, delivery, or the health of the newborn infant. PMID:8733495

  11. Interactive effects of mechanical ventilation, inhaled nitric oxide and oxidative stress in acute lung injury.

    PubMed

    Ronchi, Carlos Fernando; Ferreira, Ana Lucia Anjos; Campos, Fabio Joly; Kurokawa, Cilmery Suemi; Carpi, Mario Ferreira; Moraes, Marcos Aurélio; Bonatto, Rossano Cesar; Yeum, Kyung-Jin; Fioretto, Jose Roberto

    2014-01-01

    To compare conventional mechanical ventilation (CMV) and high-frequency oscillatory ventilation (HFOV), with/without inhaled nitric oxide (iNO), for oxygenation, inflammation, antioxidant/oxidative stress status, and DNA damage in a model of acute lung injury (ALI). Lung injury was induced by tracheal infusion of warm saline. Rabbits were ventilated at [Formula: see text] 1.0 and randomly assigned to one of five groups. Overall antioxidant defense/oxidative stress was assessed by total antioxidant performance assay, and DNA damage by comet assay. Ventilatory and hemodynamic parameters were recorded every 30min for 4h. ALI groups showed worse oxygenation than controls after lung injury. After 4h of mechanical ventilation, HFOV groups presented significant improvements in oxygenation. HFOV with and without iNO, and CMV with iNO showed significantly increased antioxidant defense and reduced DNA damage than CMV without iNO. Inhaled nitric oxide did not beneficially affect HFOV in relation to antioxidant defense/oxidative stress and pulmonary DNA damage. Overall, lung injury was reduced using HFOV or CMV with iNO. PMID:24148688

  12. Recruitment maneuvers in acute respiratory distress syndrome: The safe way is the best way.

    PubMed

    Santos, Raquel S; Silva, Pedro L; Pelosi, Paolo; Rocco, Patricia Rm

    2015-11-01

    Acute respiratory distress syndrome (ARDS) represents a serious problem in critically ill patients and is associated with in-hospital mortality rates of 33%-52%. Recruitment maneuvers (RMs) are a simple, low-cost, feasible intervention that can be performed at the bedside in patients with ARDS. RMs are characterized by the application of airway pressure to increase transpulmonary pressure transiently. Once non-aerated lung units are reopened, improvements are observed in respiratory system mechanics, alveolar reaeration on computed tomography, and improvements in gas exchange (functional recruitment). However, the reopening process could lead to vascular compression, which can be associated with overinflation, and gas exchange may not improve as expected (anatomical recruitment). The purpose of this review was to discuss the effects of different RM strategies - sustained inflation, intermittent sighs, and stepwise increases of positive end-expiratory pressure (PEEP) and/or airway inspiratory pressure - on the following parameters: hemodynamics, oxygenation, barotrauma episodes, and lung recruitability through physiological variables and imaging techniques. RMs and PEEP titration are interdependent events for the success of ventilatory management. PEEP should be adjusted on the basis of respiratory system mechanics and oxygenation. Recent systematic reviews and meta-analyses suggest that RMs are associated with lower mortality in patients with ARDS. However, the optimal RM method (i.e., that providing the best balance of benefit and harm) and the effects of RMs on clinical outcome are still under discussion, and further evidence is needed.

  13. Pulmonar recruitment in acute respiratory distress syndrome. What is the best strategy?

    PubMed

    Santos, Cíntia Lourenço; Samary, Cynthia dos Santos; Fiorio Júnior, Pedro Laurindo; Santos, Bruna Lourenço; Schanaider, Alberto

    2015-01-01

    Supporting patients with acute respiratory distress syndrome (ARDS), using a protective mechanical ventilation strategy characterized by low tidal volume and limitation of positive end-expiratory pressure (PEEP) is a standard practice in the intensive care unit. However, these strategies can promote lung de-recruitment, leading to the cyclic closing and reopening of collapsed alveoli and small airways. Recruitment maneuvers (RM) can be used to augment other methods, like positive end-expiratory pressure and positioning, to improve aerated lung volume. Clinical practice varies widely, and the optimal method and patient selection for recruitment maneuvers have not been determined, considerable uncertainty remaining regarding the appropriateness of RM. This review aims to discuss recent findings about the available types of RM, and compare the effectiveness, indications and adverse effects among them, as well as their impact on morbidity and mortality in ARDS patients. Recent developments include experimental and clinical evidence that a stepwise extended recruitment maneuver may cause an improvement in aerated lung volume and decrease the biological impact seen with the traditionally used sustained inflation, with less adverse effects. Prone positioning can reduce mortality in severe ARDS patients and may be an useful adjunct to recruitment maneuvers and advanced ventilatory strategies, such noisy ventilation and BIVENT, which have been useful in providing lung recruitment.

  14. [The basics on mechanical ventilation support in acute respiratory distress syndrome].

    PubMed

    Tomicic, V; Fuentealba, A; Martínez, E; Graf, J; Batista Borges, J

    2010-01-01

    Acute Respiratory Distress Syndrome (ARDS) is understood as an inflammation-induced disruption of the alveolar endothelial-epithelial barrier that results in increased permeability and surfactant dysfunction followed by alveolar flooding and collapse. ARDS management relies on mechanical ventilation. The current challenge is to determine the optimal ventilatory strategies that minimize ventilator-induced lung injury (VILI) while providing a reasonable gas exchange. The data support that a tidal volume between 6-8 ml/kg of predicted body weight providing a plateau pressure < 30 cmH₂O should be used. High positive end expiratory pressure (PEEP) has not reduced mortality, nevertheless secondary endpoints are improved. The rationale used for high PEEP argues that it prevents cyclic opening and closing of airspaces, probably the major culprit of development of VILI. Chest computed tomography has contributed to our understanding of anatomic-functional distribution patterns in ARDS. Electric impedance tomography is a technique that is radiation-free, but still under development, that allows dynamic monitoring of ventilation distribution at bedside.

  15. In search for better pharmacological prophylaxis for acute mountain sickness: looking in other directions.

    PubMed

    Lu, H; Wang, R; Xiong, J; Xie, H; Kayser, B; Jia, Z P

    2015-05-01

    Despite decades of research, the exact pathogenic mechanisms underlying acute mountain sickness (AMS) are still poorly understood. This fact frustrates the search for novel pharmacological prophylaxis for AMS. The prevailing view is that AMS results from an insufficient physiological response to hypoxia and that prophylaxis should aim at stimulating the response. Starting off from the opposite hypothesis that AMS may be caused by an initial excessive response to hypoxia, we suggest that directly or indirectly blunting-specific parts of the response might provide promising research alternatives. This reasoning is based on the observations that (i) humans, once acclimatized, can climb Mt Everest experiencing arterial partial oxygen pressures (PaO2) as low as 25 mmHg without AMS symptoms; (ii) paradoxically, AMS usually develops at much higher PaO2 levels; and (iii) several biomarkers, suggesting initial activation of specific pathways at such PaO2, are correlated with AMS. Apart from looking for substances that stimulate certain hypoxia triggered effects, such as the ventilatory response to hypoxia, we suggest to also investigate pharmacological means aiming at blunting certain other specific hypoxia-activated pathways, or stimulating their agonists, in the quest for better pharmacological prophylaxis for AMS. PMID:25778288

  16. Acute Intraoperative Pulmonary Aspiration

    PubMed Central

    Nason, Katie S.

    2015-01-01

    Synopsis Acute intraoperative aspiration is a potentially fatal complication with significant associated morbidity. Patients undergoing thoracic surgery are at increased risk for anesthesia-related aspiration, largely due to the predisposing conditions associated with this complication. Awareness of the risk factors, predisposing conditions, maneuvers to decrease risk and immediate management options by both the thoracic surgeon and the anesthesia team is imperative to reducing risk and optimizing patient outcomes associated with acute intraoperative pulmonary aspiration. Based on the root-cause analyses that many of the aspiration events can be traced back to provider factors, having an experienced anesthesiologist present for high-risk cases is also critical. PMID:26210926

  17. The Acute Abdominal Aorta.

    PubMed

    Mellnick, Vincent M; Heiken, Jay P

    2015-11-01

    Acute disorders of the abdominal aorta are potentially lethal conditions that require prompt evaluation and treatment. Computed tomography (CT) is the primary imaging method for evaluating these conditions because of its availability and speed. Volumetric CT acquisition with multiplanar reconstruction and three-dimensional analysis is now the standard technique for evaluating the aorta. MR imaging may be useful for select applications in stable patients in whom rupture has been excluded. Imaging is indispensable for diagnosis and treatment planning, because management has shifted toward endoluminal repair. Acute abdominal aortic conditions most commonly are complications of aneurysms and atherosclerosis. PMID:26526434

  18. Acute rheumatic fever

    PubMed Central

    Cumming, Gordon R.

    1974-01-01

    While rheumatic fever is relatively uncommon except where there are poor and crowded living conditions, sporadic acute attacks continue to occur in a family or pediatric medical practice. The physician's role in management of the sore throat in the diagnosis of suspected cases of rheumatic fever and in follow-up for continued prophylaxis is discussed. The frequency of admissions and presenting features of 159 patients with acute rheumatic fever is reviewed. Continued surveillance is required if we are to achieve a further reduction in attack rate and complications. PMID:4419123

  19. Acute sinusitis in children.

    PubMed

    Brook, Itzhak

    2013-04-01

    Acute rhinosinusitis is a common illness in children. Viral upper respiratory tract infection is the most common presentation of rhinosinusitis. Most children resolve the infection spontaneously and only a small proportion develops a secondary bacterial infection. The proper choice of antibiotic therapy depends on the likely infecting pathogens, bacterial antibiotic resistance, and pharmacologic profiles of antibiotics. Amoxicillin-clavulanate is currently recommended as the empiric treatment in those requiring antimicrobial therapy. Isolation of the causative agents should be considered in those who failed the initial treatment. In addition to antibiotics, adjuvant therapies and surgery may be used in the management of acute bacterial rhinosinusitis.

  20. What Is Acute Myeloid Leukemia?

    MedlinePlus

    ... about acute myeloid leukemia? What is acute myeloid leukemia? Cancer starts when cells in a part of ... the body from doing their jobs. Types of leukemia Not all leukemias are the same. There are ...

  1. Nutrition, Inflammation, and Acute Pancreatitis

    PubMed Central

    Petrov, Max

    2013-01-01

    Acute pancreatitis is acute inflammatory disease of the pancreas. Nutrition has a number of anti-inflammatory effects that could affect outcomes of patients with pancreatitis. Further, it is the most promising nonspecific treatment modality in acute pancreatitis to date. This paper summarizes the best available evidence regarding the use of nutrition with a view of optimising clinical management of patients with acute pancreatitis. PMID:24490104

  2. [Acute pancreatitis and pregnancy].

    PubMed

    Scollo, P; Licitra, G

    1993-12-01

    Aetiologic factors (gallstones, hyperlipidemia I-IV, hypertriglyceridaemia) make their occurrence, mainly, in the third trimester of gestation. Two cases of acute pancreatitis in pregnancy are described; in both cases patients referred healthy diet, no habit to smoke and no previous episode of pancreatitis. An obstructive pathology of biliary tract was the aetiologic factor. Vomiting, upper abdominal pain are aspecific symptoms that impose a differential diagnosis with acute appendicitis, cholecystitis and obstructive intestinal pathology. Laboratory data (elevated serum amylase and lipase levels) and ultrasonography carry out an accurate diagnosis. The management of acute pancreatitis is based on the use of symptomatic drugs, a low fat diet alternated to the parenteral nutrition when triglycerides levels are more than 28 mmol/L. Surgical therapy, used only in case of obstructive pathology of biliary tract, is optimally collected in the third trimester or immediately after postpartum. Our patients, treated only medically, delivered respectively at 38th and 40th week of gestation. Tempestivity of diagnosis and appropriate therapy permit to improve prognosis of a pathology that, although really associated with pregnancy, presents high maternal mortality (37%) cause of complications (shock, coagulopathy, acute respiratory insufficiency) and fetal (37.9%) by occurrence of preterm delivery.

  3. [Acute arsenic poisoning].

    PubMed

    Montelescaut, Etienne; Vermeersch, Véronique; Commandeur, Diane; Huynh, Sophie; Danguy des Deserts, Marc; Sapin, Jeanne; Ould-Ahmed, Mehdi; Drouillard, Isabelle

    2014-01-01

    Acute arsenic poisoning is a rare cause of suicide attempt. It causes a multiple organs failure caused by cardiogenic shock. We report the case of a patient admitted twelve hours after an ingestion of trioxide arsenic having survived thanks to a premature treatment.

  4. [Acute arsenic poisoning].

    PubMed

    Montelescaut, Etienne; Vermeersch, Véronique; Commandeur, Diane; Huynh, Sophie; Danguy des Deserts, Marc; Sapin, Jeanne; Ould-Ahmed, Mehdi; Drouillard, Isabelle

    2014-01-01

    Acute arsenic poisoning is a rare cause of suicide attempt. It causes a multiple organs failure caused by cardiogenic shock. We report the case of a patient admitted twelve hours after an ingestion of trioxide arsenic having survived thanks to a premature treatment. PMID:25486670

  5. Acute radiation risk models

    NASA Astrophysics Data System (ADS)

    Smirnova, Olga

    Biologically motivated mathematical models, which describe the dynamics of the major hematopoietic lineages (the thrombocytopoietic, lymphocytopoietic, granulocytopoietic, and erythropoietic systems) in acutely/chronically irradiated humans are developed. These models are implemented as systems of nonlinear differential equations, which variables and constant parameters have clear biological meaning. It is shown that the developed models are capable of reproducing clinical data on the dynamics of these systems in humans exposed to acute radiation in the result of incidents and accidents, as well as in humans exposed to low-level chronic radiation. Moreover, the averaged value of the "lethal" dose rates of chronic irradiation evaluated within models of these four major hematopoietic lineages coincides with the real minimal dose rate of lethal chronic irradiation. The demonstrated ability of the models of the human thrombocytopoietic, lymphocytopoietic, granulocytopoietic, and erythropoietic systems to predict the dynamical response of these systems to acute/chronic irradiation in wide ranges of doses and dose rates implies that these mathematical models form an universal tool for the investigation and prediction of the dynamics of the major human hematopoietic lineages for a vast pattern of irradiation scenarios. In particular, these models could be applied for the radiation risk assessment for health of astronauts exposed to space radiation during long-term space missions, such as voyages to Mars or Lunar colonies, as well as for health of people exposed to acute/chronic irradiation due to environmental radiological events.

  6. Acute coronary care 1986

    SciTech Connect

    Califf, R.M.; Wagner, G.S.

    1985-01-01

    This book contains 22 chapters. Some of the titles are: The measurement of acute myocardial infarct size by CT; Magnetic resonance imaging for evaluation of myocardial ischemia and infarction; Poistron imaging in the evaluation of ischemia and myocardial infarction; and New inotropic agents.

  7. Acute and chronic pancreatitis.

    PubMed

    Vlodov, J; Tenner, S M

    2001-09-01

    Acute pancreatitis has multiple causes, an unpredictable course, and myriad complications. The diagnosis relies on a combination of history, physical examination, serologic markers, and radiologic findings. The mainstay of therapy includes aggressive hydration, maintenance of NPO, and adequate analgesia with narcotics. Antibiotic and nutritional support with total parenteral nutrition should be used when appropriate.

  8. Low back pain - acute

    MedlinePlus

    Backache; Low back pain; Lumbar pain; Pain - back; Acute back pain; Back pain - new; Back pain - short-term; Back strain - new ... lower back supports most of your body's weight. Low back pain is the number two reason that Americans see ...

  9. [Management of acute tendinitis].

    PubMed

    Rapp, H J; Heisse, K; Becker, M; Stechele, M

    1992-12-01

    Ultrasonography must be used in combination with physical examination for the appropriate diagnosis of acute tendon injuries. Therapy should be designed to return the tendon to its normal function and appearance. Local and systemic anti-inflammatory agents, cold hydrotherapy and massage minimize excessive scar formation and progressively increasing tensile forces directs scar tissue to replace the tendon function.

  10. Acute streptococcal necrotising fasciitis.

    PubMed

    Frankish, P D; Mason, G H; Allen, P R; Milsom, F P; Christmas, T I

    1988-10-12

    Two cases of acute streptococcal necrotising fasciitis are reported. Both patients were taking nonsteroidal antiinflammatory drugs when they developed this infection. Urgent surgical debridement was undertaken and resulted in a successful outcome in both patients. The clinical and histopathological features of this condition are reviewed.

  11. Acute responses to exercise training and relationship with exercise adherence in moderate chronic obstructive pulmonary disease.

    PubMed

    Rizk, Amanda K; Wardini, Rima; Chan-Thim, Emilie; Bacon, Simon L; Lavoie, Kim L; Pepin, Véronique

    2015-11-01

    The objectives of our study were to (i) compare, in chronic obstructive pulmonary disease (COPD) patients, acute responses to continuous training at high intensity (CTHI), continuous training at ventilatory threshold (CTVT) and interval training (IT); (ii) examine associations between acute responses and 12-week adherence; and (iii) investigate whether the relationship between acute responses and adherence is mediated/moderated by affect/vigour. Thirty-five COPD patients (forced expiratory volume in 1 second = 60.2 ± 15.8% predicted), underwent baseline assessments, were randomly assigned to CTHI, CTVT or IT, were monitored throughout about before training, and underwent 12 weeks of exercise training during which adherence was tracked. Compared with CTHI, CTVT was associated with lower respiratory exchange ratio, heart rate and respiratory rate (RR), while IT induced higher [Formula: see text], [Formula: see text]maximal voluntary ventilation, RR and lower pulse oxygen saturation. From pre- to post-exercise, positive affect increased (F = 9.74, p < 0.001) and negative affect decreased (F = 6.43, p = 0.005) across groups. CTVT reported greater end-exercise vigour compared to CTHI (p = 0.01) and IT (p = 0.02). IT exhibited lowest post-exercise vigour (p = 0.04 versus CTHI, p = 0.02 versus CTVT) and adherence rate (F = 6.69, p = 0.004). Mean [Formula: see text] (r = -0.466, p = 0.007) and end-exercise vigour (r = 0.420, p = 0.017) were most strongly correlated with adherence. End-exercise vigour moderated the relationship between [Formula: see text] and adherence (β = 2.74, t(32) = 2.32, p = 0.03). In summary, CTHI, CTVT and IT improved affective valence from rest to post-exercise and induced a significant 12-week exercise training effect. However, they elicited different acute physiological responses, which in turn were associated with differences in 12-week adherence to the target training intensity. This association was moderated by acute end-exercise vigour.

  12. The management of acute pericarditis.

    PubMed

    Wells, T A; Curzen, N P

    2005-01-01

    Acute pericarditis is usually a benign self-limiting condition, often of unexplained or viral aetiology, involving inflammation of the pericardial layers. It is often part of the differential diagnosis in patients admitted with acute chest pain and can be confused with acute myocardial infarction, acute pulmonary embolism and pleurisy. Occasionally it can result in cardiac tamponade and, if associated with myocarditis, in heart failure. This article sets out how to diagnose acute pericarditis, the common underlying causes, the possible treatment options and outcomes. PMID:21655516

  13. Acute gangrenous cholecystitis: radionuclide diagnosis

    SciTech Connect

    Brachman, M.B.; Tanasescu, D.E.; Ramanna, L.; Waxman, A.D.

    1984-04-01

    Radionuclide hepatobiliary imaging with Tc-99m IDA is a useful procedure for the diagnosis of acute cholecystitis. Visualization of the gallbladder essentially rules out acute cholecystitis. Nonvisualization suggest acute cholecystitis but may also be associated with chronic gallbladder disease or other conditions. The authors recently observed five patients in whom a rim of increased parenchymal liver activity was seen adjacent to the gallbladder fossa. All five patients had acute gangrenous cholecystitis. The rim of increased activity appears to be a useful secondary sign of acute cholecystitis.

  14. The effect of changing the sequence of cuff inflation and device fixation with the LMA-Supreme® on device position, ventilatory complications, and airway morbidity: a clinical and fiberscopic study

    PubMed Central

    2014-01-01

    Background The conventional sequence when using supraglottic airway devices is insertion, cuff inflation and fixation. Our hypothesis was that a tighter fit of the cuff and tip could be achieved with a consequently lower incidence of air leak, better separation of gastrointestinal and respiratory tracts and less airway morbidity if the device were first affixed and the cuff then inflated. Methods Our clinical review board approved the study (public registry number DRKS00003174). An LMA Supreme® was inserted into 184 patients undergoing lower limb arthroscopy in propofol-remifentanil anaesthesia who were randomly assigned to either the control (inflation then fixation; n = 92) or study group (fixation then inflation; n = 92). The cuff was inflated to 60 cmH2O. The patients’ lungs were ventilated in pressure-controlled mode with 5 cmH2O PEEP, Pmax to give 6 ml kg-1 tidal volume, and respiratory rate adjusted to end-tidal CO2 of 4.8 and 5.6 kPa. Correct cuff and tip position were determined by leak detection, capnometry trace, oropharyngeal leak pressure, suprasternal notch test, and lube-tube test. Bowl and cuff position and the presence of glottic narrowing were assessed by fiberscopic examination. Postoperative dysphagia, hoarseness and sore throat were assessed with a questionnaire. Ventilatory impairment was defined as a tidal volume < 6 ml kg-1 with Pmax at oropharyngeal leak pressure, glottic narrowing was defined as an angle between the vocal cords under 16 degrees. Results The incidence of incorrect device position (18% vs. 21%), failed ventilation (10% vs. 9%), leak pressure (24.8 vs. 25.2 cmH2O, p = 0.63), failed lube-tube test (16.3% vs. 17.6%) and glottic narrowing (19.3% vs. 14.1%, p = 0.35) was similar in both groups (control vs. study, resp.). When glottic narrowing occurred, it was more frequently associated with ventilatory impairment in the control group (77% vs. 39%; p = 0.04). Airway morbidity was more common in the

  15. A critical role of acute bronchoconstriction in the mortality associated with high-dose sarin inhalation: Effects of epinephrine and oxygen therapies

    SciTech Connect

    Gundavarapu, Sravanthi; Zhuang, Jianguo; Barrett, Edward G.; Xu, Fadi; Russell, Robert G.; Sopori, Mohan L.

    2014-01-15

    Sarin is an organophosphate nerve agent that is among the most lethal chemical toxins known to mankind. Because of its vaporization properties and ease and low cost of production, sarin is the nerve agent with a strong potential for use by terrorists and rouge nations. The primary route of sarin exposure is through inhalation and, depending on the dose, sarin leads to acute respiratory failure and death. The mechanism(s) of sarin-induced respiratory failure is poorly understood. Sarin irreversibly inhibits acetylcholine esterase, leading to excessive synaptic levels of acetylcholine and, we have previously shown that sarin causes marked ventilatory changes including weakened response to hypoxia. We now show that LD{sub 50} sarin inhalation causes severe bronchoconstriction in rats, leading to airway resistance, increased hypoxia-induced factor-1α, and severe lung epithelium injury. Transferring animals into 60% oxygen chambers after sarin exposure improved the survival from about 50% to 75% at 24 h; however, many animals died within hours after removal from the oxygen chambers. On the other hand, if LD{sub 50} sarin-exposed animals were administered the bronchodilator epinephrine, > 90% of the animals survived. Moreover, while both epinephrine and oxygen treatments moderated cardiorespiratory parameters, the proinflammatory cytokine surge, and elevated expression of hypoxia-induced factor-1α, only epinephrine consistently reduced the sarin-induced bronchoconstriction. These data suggest that severe bronchoconstriction is a critical factor in the mortality induced by LD{sub 50} sarin inhalation, and epinephrine may limit the ventilatory, inflammatory, and lethal effects of sarin. - Highlights: • Inhalation exposure of rats to LD{sub 50} sarin causes death through respiratory failure. • Severe bronchoconstriction is the major cause of sarin-induced respiratory failure. • Transfer of sarin exposed rats to 60% oxygen improves the mortality temporarily.

  16. Acute pain management.

    PubMed

    Hansen, B

    2000-07-01

    We encounter patients with acute pain many times each day, and few aspects of veterinary practice offer such an opportunity to help so many in such a profoundly rewarding way. As emphasized here and elsewhere, we now have excellent tools with which to help these animals, and the biggest impediment to optimal treatment of their pain is often our own difficulty in recognizing its presence. Perhaps the single most important aspect of treating acute pain is to cultivate an ability to see past our personal biases and expectations which may limit treatment and to rediscover the common sense we had about pain before we entered the profession. By rededicating ourselves to seeking out, preventing, and relieving pain, we not only perform a vital service for our patients but also elevate our profession even as we reap financial and spiritual rewards for our efforts. What could be better? PMID:10932832

  17. [Schistosomiasis and acute appendicitis].

    PubMed

    Figueiredo, Jacinta; Santos, Ângela; Clemente, Horácio; Lourenço, Augusto; Costa, Sandra; Grácio, Maria Amélia; Belo, Silvana

    2014-01-01

    Acute appendicitis associated to Schistosoma haematobium and S. mansoni infection has been found in patients submitted to urgent appendectomy at the Hospital Américo Boavida in Luanda. Due to the high prevalence and morbidity caused by schistosomiasis (or bilharziasis) in the country, we suspect that the involvement of Schistosoma infection on appendicular pathology could be very frequent, in particular for those individuals more exposed to the parasite transmission. We report two clinical cases of acute appendicitis whose surgical specimens of the appendix revealed S. haematobium and S. mansoni eggs in histological samples. The reported patients live in endemic areas and have been exposed to schistosome during childhood, which may explain the infection's chronicity. Information of these clinical cases could be relevant, particularly for surgery specialists and clinical pathologists, due to the possibility of finding more patients with concurrent appendicitis and schistosomiasis.

  18. Acute aortic syndrome

    PubMed Central

    2016-01-01

    Acute aortic syndrome (AAS) is a term used to describe a constellation of life-threatening aortic diseases that have similar presentation, but appear to have distinct demographic, clinical, pathological and survival characteristics. Many believe that the three major entities that comprise AAS: aortic dissection (AD), intramural hematoma (IMH) and penetrating aortic ulcer (PAU), make up a spectrum of aortic disease in which one entity may evolve into or coexist with another. Much of the confusion in accurately classifying an AAS is that they present with similar symptoms: typically acute onset of severe chest or back pain, and may have similar radiographic features, since the disease entities all involve injury or disruption of the medial layer of the aortic wall. The accurate diagnosis of an AAS is often made at operation. This manuscript will attempt to clarify the similarities and differences between AD, IMH and PAU of the ascending aorta and describe the challenges in distinguishing them from one another. PMID:27386405

  19. Acute organophosphorus poisoning.

    PubMed

    Chowdhary, Sheemona; Bhattacharyya, Rajasri; Banerjee, Dibyajyoti

    2014-04-20

    Acute organophosphorus poisoning continues to be a detrimental problem and a potential cause of mortality especially in developing countries. Inhibition of acetylcholinesterase enzyme is the main mechanism of toxicity of such pesticides and measurement of acetylcholinesterase activity is the commonly used laboratory diagnosis approved for the purpose. It is now proved beyond any doubt that early intervention is beneficial for cases of acute organophosphorus poisoning and, therefore, considerable current interest has been generated for development of point of care testing tool for screening of the same. However, to the best of our knowledge so far the matter is not reviewed from the view of point of care testing tool development. In this paper, this subject is reviewed highlighting the methodological aspects and point of care testing tool development in the context of organophosphorus poisoning.

  20. [Acute pancreatitis and pregnancy].

    PubMed

    Laraki, M; Harti, A; Bouderka, M A; Barrou, H; Matar, N; Benaguida, M

    1993-10-01

    Acute pancreatitis during pregnancy is a serious condition and diagnosis is often difficult. The authors report the case of a 32-year-old woman in the 32nd week of her fifth pregnancy, in which the outcome was fatal for both mother and child. The cause of pancreatitis during pregnancy has been attributed to many factors, chiefly cholelithiasis. A number of recent studies have shown the relationship existing between the role played by pregnancy in predisposing to gallbladder disease with lithiasis. Many diagnosis errors are made in this condition. Thus modern treatment methods have improved the prognosis in acute pancreatitis but, when it occurs during pregnancy, diagnostic delays often lead to a gloomy outlook. PMID:8248696

  1. Acute aortic syndrome.

    PubMed

    Corvera, Joel S

    2016-05-01

    Acute aortic syndrome (AAS) is a term used to describe a constellation of life-threatening aortic diseases that have similar presentation, but appear to have distinct demographic, clinical, pathological and survival characteristics. Many believe that the three major entities that comprise AAS: aortic dissection (AD), intramural hematoma (IMH) and penetrating aortic ulcer (PAU), make up a spectrum of aortic disease in which one entity may evolve into or coexist with another. Much of the confusion in accurately classifying an AAS is that they present with similar symptoms: typically acute onset of severe chest or back pain, and may have similar radiographic features, since the disease entities all involve injury or disruption of the medial layer of the aortic wall. The accurate diagnosis of an AAS is often made at operation. This manuscript will attempt to clarify the similarities and differences between AD, IMH and PAU of the ascending aorta and describe the challenges in distinguishing them from one another. PMID:27386405

  2. Cytokines and acute pancreatitis.

    PubMed

    Brady, M; Christmas, S; Sutton, R; Neoptolemos, J; Slavin, J

    1999-07-01

    Cytokines have been shown to play a pivotal role in multiple organ dysfunction, a major cause of death in severe acute pancreatitis. Moreover, the two-hit hypothesis of the cytokine-induced systemic inflammatory response syndrome explains the variable individual response to severe acute pancreatitis and the impact of secondary events such as sepsis or therapeutic intervention. Many experimental anti-cytokine therapies have been administered following induction of experimental pancreatitis, and have proved to be therapeutic. Patients with severe pancreatitis present early because of pain. Clearly then a window for therapeutic intervention is available between onset of symptoms and peak pro-inflammatory cytokine expression. It is this fundamental observation that convinces many in the field that the treatment of AP will be one of the first clinical successes for novel drugs or therapy that seek to modulate the inflammatory response.

  3. Acute arsenic intoxication.

    PubMed

    Campbell, J P; Alvarez, J A

    1989-12-01

    The diagnosis of acute arsenic poisoning should be considered in any patient presenting with severe gastrointestinal complaints. Signs and symptoms include nausea, vomiting, colicky abdominal pain and profuse, watery diarrhea. Hypotension, fluid and electrolyte disturbances, mental status changes, electrocardiographic abnormalities, respiratory failure and death can result. Quantitative measurement of 24-hour urinary arsenic excretion is the only reliable laboratory test to confirm arsenic poisoning. Treatment includes gastric emesis or lavage, chelation therapy, electrolyte and fluid replacement, and cardiorespiratory support.

  4. [Acute Chest Pain].

    PubMed

    Gmür, Christian

    2016-02-17

    Acute chest pain is a frequent consultation reason in general practice as well as in emergency departments. With the help of history, physical examination, ECG, laboratory and newly developed risk scores, potentially life-threatening diseases and high-risk patients may be detected and treated early, quickly and cost-effectively. New biomarkers and their combination with risk scores can increase the negative predictive value to exclude certain diseases. PMID:26886697

  5. IMMUNOTHERAPY IN ACUTE LEUKEMIA

    PubMed Central

    Leung, Wing

    2010-01-01

    Recent advances in immunotherapy of cancer may represent a successful example in translational research, in which progress in knowledge and technology in immunology has lead to new strategies of immunotherapy, and even past failure in many clinical trials have led to a better understanding of basic cancer immunobiology. This article reviews the latest concepts in antitumor immunology and its application in the treatment of cancer, with particular focus on acute leukemia. PMID:19100371

  6. Neuropsychology of acute stroke.

    PubMed

    Sinanović, Osman

    2010-06-01

    Neuropsychology includes both the psychiatric manifestations of neurological illness (primary brain-based disorders) and neurobiology of "idiopathic" psychiatric disorders. Neurological primary brain disorders provoke broad spectrum of brain pathophysiology that cause deficit sin human behaviour, and the magnitude of neurobehavioral-related problems is a world wide health concern. Speech disorders of aphasic type, unilateral neglect, anosognosia (deficit disorders), delirium and mood disorders (productive disorders) in urgent neurology, first of all in acute phase of stroke are more frequent disorders then it verified in routine exam, not only in the developed and large neurological departments. Aphasia is common consequence of left hemispheric lesion and most common neuropsychological consequence of stroke, with prevalence of one third of all stroke patients in acute phase although exist reports on greater frequency. Unilateral neglect is a disorder that mostly effects the patient after the lesion of the right hemisphere, mostly caused by a cerebrovascular insult (infarct or haemorrhage affecting a large area - up to two thirds of the right hemisphere), and in general the left-side neglect is the most widespread neuropsychological deficit after the lesion of the right cerebral hemisphere. Reports on the incidence of visual neglect vary and they range from 13 to 85%. Anosognosia is on the second place as neuropsychological syndrome of stroke in right hemisphere, characterized by the denial of the motor, visual or cognitive deficit. This syndrome, defined as denial of hemiparesis or hemianopsia, is a common disorder verified in 17-28% of all patents with acute brain stoke. There are different reports on frequency of delirium in acute stroke, from 24 to 48%, and it is more frequent in hemorrhagic then ischemic stoke. Post stroke depression (PSD) is one of the more frequent consequences on the stroke, and the prevalence of PSD has ranged from 5 to 63% of patients in

  7. [Acute coronary syndromes: epidemiology].

    PubMed

    Ozkan, Alev Arat

    2013-04-01

    Coronary heart disease is the main cause of death in the world as well as in Turkey. It's not only a health issue but also a social problem with a high economic burden and negative impact on quality of life. The majority of deaths are attributable to acute coronary syndromes (ACS) and their complications.This review summarizes some important facts regarding ACS epidemiology in the world and in Turkey. PMID:27323430

  8. Diarrhoea in adults (acute)

    PubMed Central

    2008-01-01

    Introduction An estimated 4000 million cases of diarrhoea occurred worldwide in 1996, resulting in 2.5 million deaths. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of treatments for acute diarrhoea in adults living in resource-rich countries? What are the effects of treatments for acute mild-to-moderate diarrhoea in adults from resource-rich countries traveling to resource-poor countries? What are the effects of treatments for acute mild-to-moderate diarrhoea in adults living in resource-poor countries? What are the effects of treatments for acute severe diarrhoea in adults living in resource-poor countries? We searched: Medline, Embase, The Cochrane Library and other important databases up to January 2007 (BMJ Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found 71 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review we present information relating to the effectiveness and safety of the following interventions: antibiotics, antimotility agents, antisecretory agents, bismuth subsalicylate, diet, intravenous rehydration, nasogastric tube rehydration, and oral rehydration solutions (amino acid oral rehydration solution, bicarbonate oral rehydration solution, reduced osmolarity oral rehydration solution, rice-based oral rehydration solution, standard oral rehydration solution). PMID:19450323

  9. Diarrhoea in adults (acute)

    PubMed Central

    2011-01-01

    Introduction An estimated 4.6 billion cases of diarrhoea occurred worldwide in 2004, resulting in 2.2 million deaths. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of treatments for acute diarrhoea in adults living in resource-rich countries? What are the effects of treatments for acute mild-to-moderate diarrhoea in adults from resource-rich countries travelling to resource-poor countries? What are the effects of treatments for acute mild-to-moderate diarrhoea in adults living in resource-poor countries? What are the effects of treatments for acute severe diarrhoea in adults living in resource-poor countries? We searched: Medline, Embase, The Cochrane Library, and other important databases up to January 2010 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found 72 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review we present information relating to the effectiveness and safety of the following interventions: antibiotics, antimotility agents, antisecretory agents, bismuth subsalicylate, diet, intravenous rehydration, nasogastric tube rehydration, oral rehydration solutions (amino acid oral rehydration solution, bicarbonate oral rehydration solution, reduced osmolarity oral rehydration solution, rice-based oral rehydration solution, standard oral rehydration solution), vitamin A supplementation, and zinc supplementation. PMID:21718555

  10. Acupuncture for acute hordeolum

    PubMed Central

    Cheng, Ke; Wang, Xue; Guo, Menghu; Wieland, L. Susan; Shen, Xueyong; Lao, Lixing

    2014-01-01

    This is the protocol for a review and there is no abstract. The objectives are as follows: The objective of this review is to determine the effects and, when possible, the safety of acupuncture for the treatment of acute hordeola, in comparison to no specific treatment (e.g., observation), sham acupuncture, or other active treatments. Acupuncture as an adjuvant to another treatment also will be compared to that treatment alone. PMID:25214814

  11. Diagnosis of acute rhinosinusitis.

    PubMed

    Esposito, Susanna; Marchisio, Paola; Tenconi, Rossana; Tagliaferri, Laura; Albertario, Giada; Patria, Maria Francesca; Principi, Nicola

    2012-08-01

    Rhinosinusitis is almost always a complication of a viral infection involving the upper respiratory tract. A common cold is the first symptom of rhinosinusitis, but infectious processes involving the nose inevitably affect the paranasal sinuses because of their anatomical contiguity. The symptoms remain those of a common cold as long as nasal phlogosis is moderate and the ostia between the nose and sinuses are patent. If the inflammation is intense, edema may obliterate the ostia and isolate the sinuses, thus stopping the removal of the exudates. The duration of symptoms makes it possible to distinguish acute (10-30 days) from subacute (30-90 days) and chronic rhinosinusitis (>90 days). The diagnosis of rhinosinusitis should only be based on anamnestic and clinical criteria in children with serious or persistent symptoms of upper respiratory tract infection, or which appear within a short time of an apparent recovery. Computed tomography and magnetic resonance images of the paranasal sinuses should be reserved for children reasonably considered to be candidates for surgery. Antibiotics are recommended in cases of mild acute bacterial rhinosinusitis as a means of accelerating the resolution of symptoms. The use of antibiotics is mandatory in severe acute bacterial rhinosinusitis to cure the disease and avoid the possible onset of severe complications.

  12. Acute lung injury review.

    PubMed

    Tsushima, Kenji; King, Landon S; Aggarwal, Neil R; De Gorordo, Antonio; D'Alessio, Franco R; Kubo, Keishi

    2009-01-01

    The first report of acute respiratory distress syndrome (ARDS) was published in 1967, and even now acute lung injury (ALI) and ARDS are severe forms of diffuse lung disease that impose a substantial health burden all over the world. Recent estimates indicate approximately 190,000 cases per year of ALI in the United States each year, with an associated 74,500 deaths per year. Common causes of ALI/ARDS are sepsis, pneumonia, trauma, aspiration pneumonia, pancreatitis, and so on. Several pathologic stages of ALI/ARDS have been described: acute inflammation with neutrophil infiltration, fibroproliferative phase with hyaline membranes, with varying degrees of interstitial fibrosis, and resolution phase. There has been intense investigation into the pathophysiologic events relevant to each stage of ALI/ARDS, and much has been learned in the alveolar epithelial, endobronchial homeostasis, and alveolar cell immune responses, especially neutrophils and alveolar macrophages in an animal model. However, these effective results in the animal models are not equally adoptive to those in randomized, controlled trials. The clinical course of ALI/ARDS is variable with the likely pathophysiologic complexity of human ALI/ARDS. In 1994, the definition was recommended by the American-European Consensus Conference Committee, which facilitated easy nomination of patients with ALI/ARDS for a randomized, clinical trial. Here, we review the recent randomized, clinical trials of ALI/ARDS.

  13. Medical treatment of acute pancreatitis.

    PubMed

    Mayerle, Julia; Simon, Peter; Lerch, Markus M

    2004-12-01

    Eighty percent of all cases of acute pancreatitis are linked etiologically to gallstone disease or caused by immoderate alcohol consumption. No specific causal treatment for acute pancreatitis exists. Early prognostic factors that indicate severe disease are three or more signs on organ failure scores according to Ranson, Imrie, or Acute Physiology and Chronic Health Evaluation (APACHE) 11, extrapancreatic complications of the disease, or the detection of pancreatic necrosis on CT scans. Elevated CRP levels above 130 mg/L can also predict a severe course of acute pancreatitis. The essential medical treatment for acute pancreatitis is the correction of hypovolemia. Moreover, relief of often severe visceral pain is a high priority. Prophylactic antibiotics should be restricted to patients with necrotizing pancreatitis, infected necrosis, or other infectious complications. Enteral nutrition has no adverse effect compared with parenteral nutrition during the course of acute pancreatitis, and is probably beneficial in regard to outcome.

  14. Targeted Therapy in Treating Patients With Relapsed or Refractory Acute Lymphoblastic Leukemia or Acute Myelogenous Leukemia

    ClinicalTrials.gov

    2016-07-28

    Chronic Myelomonocytic Leukemia; Myelodysplastic Syndrome; Recurrent Acute Myeloid Leukemia With Myelodysplasia-Related Changes; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Adult Acute Myeloid Leukemia; Refractory Adult Acute Lymphoblastic Leukemia

  15. [Computer tomography in acute pyelonephritis].

    PubMed

    Triller, J; Scheidegger, J; Terrier, F

    1983-07-01

    Computer tomography of the kidneys was performed on 30 patients with acute renal infections (acute suppurative pyelonephritis, acute renal abscess, infected cyst, pyelonephrosis, calculus perforation, retroperitoneal abscess). Computer tomography provided more accurate information concerning the extent of the renal and extra-renal inflammatory process than did the urogram or sonogram. This may significantly affect the choice of treatment, particularly concerning the use of drugs or of surgery. Angiography and retrograde pyelography may be used in selected cases, especially where there is a suspicion of acute bacterial nephritis, renal vein thrombosis or ureteric obstruction.

  16. Acute exacerbation of COPD.

    PubMed

    Ko, Fanny W; Chan, Ka Pang; Hui, David S; Goddard, John R; Shaw, Janet G; Reid, David W; Yang, Ian A

    2016-10-01

    The literature of acute exacerbation of chronic obstructive pulmonary disease (COPD) is fast expanding. This review focuses on several aspects of acute exacerbation of COPD (AECOPD) including epidemiology, diagnosis and management. COPD poses a major health and economic burden in the Asia-Pacific region, as it does worldwide. Triggering factors of AECOPD include infectious (bacteria and viruses) and environmental (air pollution and meteorological effect) factors. Disruption in the dynamic balance between the 'pathogens' (viral and bacterial) and the normal bacterial communities that constitute the lung microbiome likely contributes to the risk of exacerbations. The diagnostic approach to AECOPD varies based on the clinical setting and severity of the exacerbation. After history and examination, a number of investigations may be useful, including oximetry, sputum culture, chest X-ray and blood tests for inflammatory markers. Arterial blood gases should be considered in severe exacerbations, to characterize respiratory failure. Depending on the severity, the acute management of AECOPD involves use of bronchodilators, steroids, antibiotics, oxygen and noninvasive ventilation. Hospitalization may be required, for severe exacerbations. Nonpharmacological interventions including disease-specific self-management, pulmonary rehabilitation, early medical follow-up, home visits by respiratory health workers, integrated programmes and telehealth-assisted hospital at home have been studied during hospitalization and shortly after discharge in patients who have had a recent AECOPD. Pharmacological approaches to reducing risk of future exacerbations include long-acting bronchodilators, inhaled steroids, mucolytics, vaccinations and long-term macrolides. Further studies are needed to assess the cost-effectiveness of these interventions in preventing COPD exacerbations.

  17. Acute panmyelosis with myelofibrosis.

    PubMed

    Thiele, Juergen; Kvasnicka, Hans M; Schmitt-Graeff, Annette

    2004-04-01

    Acute panmyelosis with myelofibrosis (APMF) is an ill-defined disorder that may either evolve as a clonal hematopoietic condition or as a sequel of toxic exposure to the bone marrow (BM). Therefore, controversy and discussion continues as to whether APMF may be considered as a hyperfibrotic (de novo) myelodysplastic syndrome (MDS), as acute myeloid leukemia (AML) or as a severe toxic myelopathy with accompanying myelofibrosis. In this context scant knowledge exists about BM findings, but especially evolution of this disorder according to sequential examinations. Clinically patients present with pancytopenia, a very few blasts in the peripheral blood and no or little splenomegaly. Initially BM histopathology is characterized by different degrees of reticulin-collagen fibrosis and wide ranges of cellularity with a prominent left-shifted and often macrocytic erythropoiesis associated with a reduction and maturation defects of the neutrophil series. Most conspicuous are abnormalities of the megakaryocytes including loose clustering, dislocation towards the endosteal border and appearance of atypical microforms with compact nuclei. Moreover, besides myelofibrosis in a number of patients the interstitial compartment displays a remarkable inflammatory reaction with lymphoid nodules, abundant iron-laden macrophages, perivascular plasmacytosis and increase in microvessels. Repeatedly performed BM biopsies reveal an accumulation of dispersed or clustered CD34+ and lysozyme-expressing blasts in keeping with the insidious transformation into acute leukemia. Prognosis is unfavorable with a median survival of less than 1 year. In conclusion, APMF has to be regarded as a condition that shows considerable overlappings with primary hyperfibrotic MDS, AML and toxic myelopathy (secondary MDS) with accompanying myelofibrosis and therefore can not be considered as a definite clinical entity.

  18. Acute brain trauma.

    PubMed

    Martin, G T

    2016-01-01

    In the 20th century, the complications of head injuries were controlled but not eliminated. The wars of the 21st century turned attention to blast, the instant of impact and the primary injury of concussion. Computer calculations have established that in the first 5 milliseconds after the impact, four independent injuries on the brain are inflicted: 1) impact and its shockwave, 2) deceleration, 3) rotation and 4) skull deformity with vibration (or resonance). The recovery, pathology and symptoms after acute brain trauma have always been something of a puzzle. The variability of these four modes of injury, along with a variable reserve of neurones, explains some of this problem.

  19. [Infant acute leukemia].

    PubMed

    Brethon, Benoît; Cavé, Hélène; Fahd, Mony; Baruchel, André

    2016-03-01

    If acute leukemia is the most frequent cancer in childhood (33%), it remains a very rare diagnosis in infants less than one year old, e.g. less than 5% of cases. At this age, the frequency of acute lymphoblastic leukemia (ALL) (almost all of B-lineage) is quite similar to the one of myeloblastic forms (AML). Infant leukemia frequently presents with high hyperleucocytosis, major tumoral burden and numerous extra-hematological features, especially in central nervous system and skin. Whatever the lineage, the leukemic cell is often very immature cytologically and immunologically. Rearrangements of the Mixed Lineage Leukemia (MLL) gene, located on band 11q23, are the hallmark of these immature leukemias and confer a particular resistance to conventional approaches, corticosteroids and chemotherapy. The immaturity of infants less than 1-year-old is associated to a decrease of the tolerable dose-intensity of some drugs (anthracyclines, alkylating agents) or asks questions about some procedures like radiotherapy or high dose conditioning regimen, responsible of inacceptable acute and late toxicities. The high level of severe infectious diseases and other high-grade side effects limits also the capacity to cure these infants. The survival of infants less than 1-year-old with AML is only 50% but similar to older children. On the other hand, survival of those with ALL is the same, then quite limited comparing the 80% survival in children over one year. Allogeneic stem cell transplantations are indicated in high-risk subgroups of infant ALL (age below 6 months, high hyperleucocytosis >300.10(9)/L, MLL-rearrangement, initial poor prednisone response). However, morbidity and mortality remain very important and these approaches cannot be extended to all cases. During the neonatal period, the dismal prognosis linked to the high number of primary failures or very early relapses and uncertainties about the late toxicities question physicians about ethics. It is an emergency to

  20. Feedlot Acute Interstitial Pneumonia.

    PubMed

    Woolums, Amelia R

    2015-11-01

    Acute interstitial pneumonia (AIP) of feedlot cattle is a sporadically occurring respiratory condition that is often fatal. Affected cattle have a sudden onset of labored breathing. There is no confirmed effective treatment of feedlot AIP; however, administration of antibiotics effective against common bacterial respiratory pathogens and nonsteroidal anti-inflammatory drugs, especially aspirin, has been recommended. Protective strategies are not well defined, but efforts to limit dust exposure and heat stress; to ensure consistent formulation, mixing, and delivery of feed; and to identify and treat infectious respiratory disease in a timely manner may decrease rates of feedlot AIP.

  1. Acute otitis media.

    PubMed

    Dickson, Gretchen

    2014-03-01

    One in 4 children will have at least 1 episode of acute otitis media (AOM) by age 10 years. AOM results from infection of fluid that has become trapped in the middle ear. The bacteria that most often cause AOM are Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. Differentiating AOM from otitis media with effusion (OME) is a critical skill for physicians, as accurate diagnosis will guide appropriate treatment of these conditions. Although fluid is present in the middle ear in both conditions, the fluid is not infected in OME as is seen in AOM patients. PMID:24439877

  2. [Acute necrotizing enteritis].

    PubMed

    Marincaş, M; Bratucu, E; Straja, D; Daha, C; Boru, C

    2003-01-01

    The authors present a retrospective clinical study done on a 13-pacients basis diagnosed during surgery with acute necrotizing enteritis. This study follows the complexity of pathogenic factors and the difficulties one confronts with when establishing a diagnosis since the clinical manifestations are non-specifical and shows the contribution of laboratory data to an earliest possible diagnosis. Both medical and surgical treatment are analyzed depending on the results achieved with an attempt to determine a therapeutic approach as beneficial as possible, aiming at making clear either enterectomy or a conservatory surgical decision should be made. Mortality rate under such therapeutical approach was 38%.

  3. Acute lead arsenate poisoning.

    PubMed

    Tallis, G A

    1989-12-01

    Three cases of acute lead arsenate poisoning which occurred in South Australia during a 12 month interval are described. The case reports demonstrate a number of features of the characteristic clinical syndrome which may follow ingestion of lead arsenate. The recommended management is immediate gastric lavage and subsequent chelation therapy with calcium EDTA and dimercaprol. Early gastric lavage may prevent significant lead absorption. However, arsenic acid (produced in the stomach when lead arsenate reacts with hydrochloric acid) is relatively water soluble and prompt gastric lavage is unlikely to prevent extensive arsenic absorption. It remains controversial as to whether chelation with dimercaprol prevents arsenical neuropathy.

  4. Acute otitis media.

    PubMed

    Dickson, Gretchen

    2014-03-01

    One in 4 children will have at least 1 episode of acute otitis media (AOM) by age 10 years. AOM results from infection of fluid that has become trapped in the middle ear. The bacteria that most often cause AOM are Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. Differentiating AOM from otitis media with effusion (OME) is a critical skill for physicians, as accurate diagnosis will guide appropriate treatment of these conditions. Although fluid is present in the middle ear in both conditions, the fluid is not infected in OME as is seen in AOM patients.

  5. Acute acalculous cholecystitis.

    PubMed

    Barie, Philip S; Eachempati, Soumitra R

    2010-06-01

    Acute acalculous cholecystitis (ACC) can develop with or without gallstones after surgery and in critically ill or injured patients. Diabetes mellitus, malignant disease, abdominal vasculitis, congestive heart failure, cholesterol embolization, shock, and cardiac arrest also have been associated with AAC. The pathogenesis of AAC is complex and multifactorial. Ultrasound of the gallbladder is most accurate for the diagnosis of AAC in the critically ill patient. CT is probably of comparable accuracy, but carries both advantages and disadvantages. Rapid improvement may be expected when AAC is diagnosed correctly and cholecystostomy is performed timely. PMID:20478490

  6. Acute medial elbow ruptures.

    PubMed

    Norwood, L A; Shook, J A; Andrews, J R

    1981-01-01

    Disruption of the ulnar collateral ligament, flexor muscles, and anterior elbow capsule may result from valgus vector forces and subsequently cause difficulty in throwing, pulling, pushing and catching. Complete medial elbow tears were diagnosed acutely in four elbows by abduction stress tests at 15 degrees of flexion. Three elbows had associated ulnar nerve compression. We repaired torn medial structures by direct suture without ligamentous reconstruction. We also decompressed ulnar nerves and performed one anterior transposition. Full range of motion, strength, and return to previous functional level was attained without infection, neurovascular compression, or myositis ossificans.

  7. Acute ischemic stroke update.

    PubMed

    Baldwin, Kathleen; Orr, Sean; Briand, Mary; Piazza, Carolyn; Veydt, Annita; McCoy, Stacey

    2010-05-01

    Stroke is the third most common cause of death in the United States and is the number one cause of long-term disability. Legislative mandates, largely the result of the American Heart Association, American Stroke Association, and Brain Attack Coalition working cooperatively, have resulted in nationwide standardization of care for patients who experience a stroke. Transport to a skilled facility that can provide optimal care, including immediate treatment to halt or reverse the damage caused by stroke, must occur swiftly. Admission to a certified stroke center is recommended for improving outcomes. Most strokes are ischemic in nature. Acute ischemic stroke is a heterogeneous group of vascular diseases, which makes targeted treatment challenging. To provide a thorough review of the literature since the 2007 acute ischemic stroke guidelines were developed, we performed a search of the MEDLINE database (January 1, 2004-July 1, 2009) for relevant English-language studies. Results (through July 1, 2009) from clinical trials included in the Internet Stroke Center registry were also accessed. Results from several pivotal studies have contributed to our knowledge of stroke. Additional data support the efficacy and safety of intravenous alteplase, the standard of care for acute ischemic stroke since 1995. Due to these study results, the American Stroke Association changed its recommendation to extend the time window for administration of intravenous alteplase from within 3 hours to 4.5 hours of symptom onset; this recommendation enables many more patients to receive the drug. Other findings included clinically useful biomarkers, the role of inflammation and infection, an expanded role for placement of intracranial stents, a reduced role for urgent carotid endarterectomy, alternative treatments for large-vessel disease, identification of nontraditional risk factors, including risk factors for women, and newly published pediatric stroke guidelines. In addition, new devices for

  8. Acute extremity compartment syndrome.

    PubMed

    Tumbarello, C

    2000-01-01

    Acute Extremity Compartment Syndrome is a disorder, which can cause loss of limb if left untreated. Compartment syndrome develops when pressures within the fascial compartments become elevated, resulting in decreased perfusion to muscles and nerves. Left untreated, tissue death occurs. Rapid identification of clinical signs can decrease severity of symptoms. Diligent nursing assessment and monitoring of clinical signs, with communication to the physician, will facilitate rapid treatment by the physician. The primary treatment option is early identification and intervention through performance of a fasciotomy.

  9. Acute Promyelocytic Leukemia

    PubMed Central

    Kingsley, Edwin C.; Durie, Brian G. M.; Garewal, Harinder S.

    1987-01-01

    Acute promyelocytic leukemia (APL) is a subtype of acute myelogenous leukemia frequently associated with disseminated intravascular coagulation (DIC). Data on 11 patients with APL treated at our institution were analyzed and compared with those of 147 published cases. Most had a bleeding diathesis at presentation and evidence of DIC eventually developed in all. Seven patients (64%) showed the t(15;17)(q22;q21) karyotype or a similar translocation. Using a chemotherapy induction regimen containing an anthracycline, complete remission, requiring a total of 14 courses of treatment, was achieved in six patients (55%). The median duration of response and median survival for complete responders were 10 and 15 months, respectively. Three patients (27%) died of bleeding complications during induction therapy. The tritiated-thymidine labeling index of leukemia cells predicted which patients would achieve a complete remission. Review of six studies of 147 patients with APL from the past 12 years supports the use of a chemotherapy induction regimen containing anthracycline or amsacrine and heparin for the treatment of DIC. PMID:3472414

  10. Acute systemic toxicity.

    PubMed

    Botham, Philip A

    2002-01-01

    Use of the test that aimed to identify the single lethal dose of a substance that kills half the animals in a test group (the LD50 test) should finally be discontinued by the end of 2002, after many years of controversy and debate. In its stead are three recently developed alternative animal tests that significantly improve animal welfare: the fixed dose procedure, the acute toxic class method, and the up and down procedure. These tests have already undergone revision, both to improve their scientific performance and, importantly, to increase their regulatory acceptance. They can now be used within a strategy of acute toxicity testing for all types of test substances and for all regulatory and in-house purposes. In vitro cytotoxicity tests could be used (perhaps by mid-2002) as adjuncts to these alternative animal tests to improve dose level selection and reduce (at least modestly) the number of animals used. However, the total replacement of animal tests requires a considerable amount of further test development, followed by validation, which will require at least 10 yr.

  11. Acute Kidney Injury.

    PubMed

    Zuk, Anna; Bonventre, Joseph V

    2016-01-01

    Acute kidney injury (AKI) is a global public health concern associated with high morbidity, mortality, and healthcare costs. Other than dialysis, no therapeutic interventions reliably improve survival, limit injury, or speed recovery. Despite recognized shortcomings of in vivo animal models, the underlying pathophysiology of AKI and its consequence, chronic kidney disease (CKD), is rich with biological targets. We review recent findings relating to the renal vasculature and cellular stress responses, primarily the intersection of the unfolded protein response, mitochondrial dysfunction, autophagy, and the innate immune response. Maladaptive repair mechanisms that persist following the acute phase promote inflammation and fibrosis in the chronic phase. Here macrophages, growth-arrested tubular epithelial cells, the endothelium, and surrounding pericytes are key players in the progression to chronic disease. Better understanding of these complex interacting pathophysiological mechanisms, their relative importance in humans, and the utility of biomarkers will lead to therapeutic strategies to prevent and treat AKI or impede progression to CKD or end-stage renal disease (ESRD).

  12. Imaging acute ischemic stroke.

    PubMed

    González, R Gilberto; Schwamm, Lee H

    2016-01-01

    Acute ischemic stroke is common and often treatable, but treatment requires reliable information on the state of the brain that may be provided by modern neuroimaging. Critical information includes: the presence of hemorrhage; the site of arterial occlusion; the size of the early infarct "core"; and the size of underperfused, potentially threatened brain parenchyma, commonly referred to as the "penumbra." In this chapter we review the major determinants of outcomes in ischemic stroke patients, and the clinical value of various advanced computed tomography and magnetic resonance imaging methods that may provide key physiologic information in these patients. The focus is on major strokes due to occlusions of large arteries of the anterior circulation, the most common cause of a severe stroke syndrome. The current evidence-based approach to imaging the acute stroke patient at the Massachusetts General Hospital is presented, which is applicable for all stroke types. We conclude with new information on time and stroke evolution that imaging has revealed, and how it may open the possibilities of treating many more patients. PMID:27432672

  13. Management of acute sunburn.

    PubMed

    Han, Amy; Maibach, Howard I

    2004-01-01

    Current literature documents the use of many pharmacologic agents in the management of acute sunburn. While numerous studies have been undertaken, there is no consensus on an algorithm for such treatment. We review the literature for an evidence-based approach to the management of sunburn. A MEDLINE search was conducted whereby all published articles related to sunburn or ultraviolet (UV)-induced erythema from 1966-2001 were evaluated. Studies and reviews were excluded if they were not conducted in human beings. The results of these studies are varying and often conflicting in terms of clinical effectiveness or feasibility. A total of 40 studies were reviewed. Fourteen out of the 40 studies addressed the actual treatment of sunburn (i.e. the application of a substance after the development of signs or symptoms). The majority concluded that either corticosteroids, NSAIDs, antioxidants, antihistamines or emollients were ineffective at decreasing recovery time. The remaining studies showed mild improvement with such treatments, but study designs or methods were flawed. Furthermore, regardless of the treatment modality, the damage to epidermal cells is the same. Given the lack of convincing data and consensus of opinion regarding sunburn management, the most effective and practical approach to acute sunburn is symptomatic treatment of UV light-induced symptoms, including erythema, pain and pruritus.

  14. Neurological emergencies: acute stroke

    PubMed Central

    Davenport, R.; Dennis, M.

    2000-01-01

    Stroke causes a vast amount of death and disability throughout the world, yet for many healthcare professionals it remains an area of therapeutic nihilism, and thus uninteresting. This negative perception is shared by the general public, who often have a poor understanding of the early symptoms and significance of a stroke. Yet within the past few years there have been many important developments in the approach to caring for stroke patients, for both the acute management and secondary prevention. After the completion of numerous clinical trials, there is now robust evidence to either support or discredit various interventions. Even more exciting is the prospect of yet more data becoming available in the near future, testing a whole array of treatments, as clinical interest in stroke expands exponentially. In this review an evidence based approach to the management of acute stroke within the first few days is presented, including ischaemic and haemorrhagic events, but not subarachnoid haemorrhage. It is explained why stroke is regarded as a medical emergency, and the importance of a rational, methodic approach to the initial assessment, which is the key to accurate diagnosis and subsequent management, is emphasised. The potential early problems associated with stroke are identified and specific interventions for different stroke types are discussed. The review ends with a brief discussion of the implications that the evolving treatments have for the organisation of modern stroke services.

 PMID:10675208

  15. Acute Bacterial Cholangitis

    PubMed Central

    Zimmer, Vincent; Lammert, Frank

    2015-01-01

    Background Acute bacterial cholangitis for the most part owing to common bile duct stones is common in gastroenterology practice and represents a potentially life-threatening condition often characterized by fever, abdominal pain, and jaundice (Charcot's triad) as well as confusion and septic shock (Reynolds' pentad). Methods This review is based on a systematic literature review in PubMed with the search items ‘cholangitis’, ‘choledocholithiasis’, ‘gallstone disease’, ‘biliary infection’, and ‘biliary sepsis’. Results Although most patients respond to empiric broad-spectrum antibiotic treatment, timely endoscopic biliary drainage depending on the severity of the disease is required to eliminate the underlying obstruction. Specific recommendations have been derived from the Tokyo guideline working group consensus 2006 and its update in 2013, albeit poorly evidence-based, providing a comprehensive overview of diagnosis, classification, risk stratification, and treatment algorithms in acute bacterial cholangitis. Conclusion Prompt clinical recognition and accurate diagnostic workup including adequate laboratory assessment and (aetiology-oriented) imaging are critical steps in the management of cholangitis. Treatment is directed at the two major interrelated pathophysiologic components, i.e. bacterial infection (immediate antimicrobial therapy) and bile duct obstruction (biliary drainage). As for the latter, transpapillary endoscopic drainage by stent or nasobiliary drain and/or same-session bile duct clearance, depending on individual disease severity, represent first-line treatment approaches. PMID:26468310

  16. Acute traumatic patellar dislocation.

    PubMed

    Duthon, V B

    2015-02-01

    Inaugural traumatic patellar dislocation is most often due to trauma sustained during physical or sports activity. Two-thirds of acute patellar dislocations occur in young active patients (less than 20 years old). Non-contact knee sprain in flexion and valgus is the leading mechanism in patellar dislocation, accounting for as many as 93% of all cases. The strong displacement of the patella tears the medial stabilizing structures, and notably the medial patellofemoral ligament (MPFL), which is almost always injured in acute patellar dislocation, most frequently at its femoral attachment. Lateral patellar glide can be assessed with the knee in extension or 20° flexion. Displacement by more than 50% of the patellar width is considered abnormal and may induce apprehension. Plain X-ray and CT are mandatory to diagnose bony risk factors for patellar dislocation, such as trochlear dysplasia or increased tibial tubercle-trochlear groove distance (TT-TG), and plan correction. MRI gives information on cartilage and capsulo-ligamentous status for treatment planning: free bodies or osteochondral fracture have to be treated surgically. If patellar dislocation occurs in an anatomically normal knee and osteochondral fracture is ruled out on MRI, non-operative treatment is usually recommended.

  17. What Is Acute Lymphocytic Leukemia (ALL)?

    MedlinePlus

    ... key statistics about acute lymphocytic leukemia? What is acute lymphocytic leukemia? Cancer starts when cells in the body begin ... leukemias). The rest of this document focuses on acute lymphocytic leukemia (ALL) in adults. For information on ALL in ...

  18. Acute diabetic abdomen in childhood.

    PubMed

    Valerio, D

    1976-01-10

    Three children presented as acute surgical emergencies due to undiagnosed diabetes mellitus. Where diabetic ketoacidosis mimicks the acute abdomen three clinical features are important in reaching the right diagnosis-namely, a history of polydipsia, polyuria, and anorexia preceding the abdominal pain, the deep sighing and rapid respirations, and severe dehydration.

  19. Acute arsenic poisoning diagnosed late.

    PubMed

    Shumy, Farzana; Anam, Ahmad Mursel; Kamruzzaman, A K M; Amin, Md Robed; Chowdhury, M A Jalil

    2016-04-01

    Acute arsenicosis, although having a 'historical' background, is not common in our times. This report describes a case of acute arsenic poisoning, missed initially due to its gastroenteritis-like presentation, but suspected and confirmed much later, when the patient sought medical help for delayed complications after about 2 months.

  20. Acute arsenic poisoning diagnosed late.

    PubMed

    Shumy, Farzana; Anam, Ahmad Mursel; Kamruzzaman, A K M; Amin, Md Robed; Chowdhury, M A Jalil

    2016-04-01

    Acute arsenicosis, although having a 'historical' background, is not common in our times. This report describes a case of acute arsenic poisoning, missed initially due to its gastroenteritis-like presentation, but suspected and confirmed much later, when the patient sought medical help for delayed complications after about 2 months. PMID:26508422

  1. New puzzles for the use of non-invasive ventilation for immunosuppressed patients.

    PubMed

    Barbas, Carmen Sílvia Valente; Serpa Neto, Ary

    2016-01-01

    On October 27, 2015, Lemile and colleagues published an article in JAMA entitled "Effect of Noninvasive Ventilation vs. Oxygen Therapy on Mortality among Immunocompromised Patients with Acute Respiratory Failure: A Randomized Clinical Trial", which investigated the effects of non-invasive ventilation (NIV) in 28-day mortality of 374 critically ill immunosuppressed patients. The authors found that among immunosuppressed patients admitted to the intensive care unit (ICU) with hypoxemic acute respiratory failure, early NIV compared with oxygen therapy alone did not reduce 28-day mortality. Furthermore, different from the previous publications, there were no significant differences in ICU-acquired infections, duration of mechanical ventilation, or lengths of ICU or hospital stays. The study power was limited, median oxygen flow used was higher than used before or 9 L/min, NIV settings provided tidal volumes higher than what is considered protective nowadays or from 7 to 10 mL/kg of ideal body weight and the hypoxemic respiratory failure was moderate to severe (median PaO2/FIO2 was around 140), a group prone to failure in noninvasive ventilatory support. Doubts arose regarding the early use of NIV in immunosuppressed critically ill patients with non-hypercapnic hypoxemic respiratory failure that need to be solved in the near future. PMID:26904233

  2. Acute pain medicine in anesthesiology

    PubMed Central

    Munro, Anastacia P.; Tighe, Patrick J.

    2013-01-01

    The American Academy of Pain Medicine and the American Society for Regional Anesthesia have recently focused on the evolving practice of acute pain medicine. There is increasing recognition that the scope and practice of acute pain therapies must extend beyond the subacute pain phase to include pre-pain and pre-intervention risk stratification, resident and fellow education in regional anesthesia and multimodal analgesia, as well as a deeper understanding of the pathophysiologic mechanisms that are integral to the variability observed among individual responses to nociception. Acute pain medicine is also being established as a vital component of successful systems-level acute pain management programs, inpatient cost containment, and patient satisfaction scores. In this review, we discuss the evolution and practice of acute pain medicine and we aim to facilitate further discussion on the evolution and advancement of this field as a subspecialty of anesthesiology. PMID:24381730

  3. Gemtuzumab Ozogamicin in Treating Patients With Relapsed or Refractory Acute Myeloid Leukemia or Acute Promyelocytic Leukemia

    ClinicalTrials.gov

    2016-07-26

    Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Del(5q); Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(15;17)(q22;q12); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); Adult Acute Promyelocytic Leukemia (M3); Childhood Acute Promyelocytic Leukemia (M3); Recurrent Adult Acute Myeloid Leukemia; Recurrent Childhood Acute Myeloid Leukemia

  4. Acute Inhalation Injury

    PubMed Central

    Gorguner, Metin; Akgun, Metin

    2010-01-01

    Inhaled substances may cause injury in pulmonary epithelium at various levels of respiratory tract, leading from simple symptoms to severe disease. Acute inhalation injury (AII) is not uncommon condition. There are certain high risk groups but AII may occur at various places including home or workplace. Environmental exposure is also possible. In addition to individual susceptibility, the characteristics of inhaled substances such as water solubility, size of substances and chemical properties may affect disease severity as well as its location. Although AII cases may recover in a few days but AII may cause long-term complications, even death. We aimed to discuss the effects of short-term exposures (minutes to hours) to toxic substances on the lungs. PMID:25610115

  5. Acute lymphoblastic leukaemia

    PubMed Central

    Inaba, Hiroto; Greaves, Mel; Mullighan, Charles G.

    2013-01-01

    Summary Acute lymphoblastic leukaemia (ALL) is seen in both children and adults, but its incidence peaks between ages 2 and 5 years. The causation of ALL is considered to be multi-factorial, including exogenous or endogenous exposures, genetic susceptibility, and chance. The survival rate of paediatric ALL has improved to approximately 90% in recent trials with risk stratification by biologic features of leukaemic cells and response to therapy, therapy modification based on patient pharmacodynamics and pharmacogenomics, and improved supportive care. However, innovative approaches are needed to further improve survival while reducing adverse effects. While most children can be cured, the prognosis of infants and adults with ALL remains poor. Recent genome-wide profiling of germline and leukaemic cell DNA has identified novel submicroscopic structural genetic alterations and sequence mutations that contribute to leukaemogenesis, define new ALL subtypes, influence responsiveness to treatment, and may provide novel prognostic markers and therapeutic targets for personalized medicine. PMID:23523389

  6. [Acute intermittent porphyria].

    PubMed

    Catania, A; Caimi, G

    1983-11-10

    Acute intermittent porphyria (AIP) is a congenital disease which as its name suggests, runs intermittently. Biochemically it is characterised by over-production of hepatic ALA synthetase (ALA-s), inducible mitochondrial enzyme and an increase in prophyrinic precursors (PBG, ac S-ALA). Clinically it is characterised by an abdominal nervous symptomatology. The primary metabolic error has been identified as a deficiency in enzyme activity which partially blocks haem biosynthesis. During the appearance of clinical manifestations, certain factors are present which have the capacity of inducing hepatic ALA-s production in vitro. Apart from some preventive measures treatment is mainly of symptomatology and complications. More recently the use of ALA-s inhibitors has been introduced. PMID:6657112

  7. Nutrition in acute pancreatitis.

    PubMed

    Nompleggi, D J

    1999-08-01

    Pancreatitis is a common disorder. Numerous factors have been implicated in the pathogenesis of acute and chronic pancreatitis, but the exact mechanisms of these conditions are still poorly understood. Depending on the cause of the disorder, patients who have pancreatitis are usually not malnourished and are able to eat within 5 to 7 days of disease onset. In these patients, nutritional support is unnecessary. However, severe disease induces a catabolic state similar to that seen in trauma and sepsis, resulting in rapid weight loss and increased morbidity and mortality. Thus, vigorous nutritional support may be useful in the treatment of severe pancreatitis. Studies have shown that parenteral and enteral nutritional support are well tolerated and can maintain or improve nutritional status in patients with pancreatitis. This article reviews nutritional assessment and therapy in pancreatitis.

  8. Acute otitis media.

    PubMed

    Atkinson, Helen; Wallis, Sebastian; Coatesworth, Andrew P

    2015-05-01

    Acute otitis media (AOM) is a common problem facing general practitioners, paediatricians and otolaryngologists. This article reviews the aetiopathogenesis, epidemiology, presentation, natural history, complications and management of AOM. The literature was reviewed by using the PubMed search engine and entering a combination of terms including 'AOM', 'epidemiology' and 'management'. Relevant articles were identified and examined for content. What is the take-home message? AOM is a very common problem affecting the majority of children at least once and places a large burden on health care systems throughout the world. Although symptomatic relief is often enough for most children, more severe and protracted cases require treatment with antibiotics, especially in younger children. PMID:25913598

  9. [Acute epiglottitis in adults].

    PubMed

    Castillo, A

    1992-09-01

    The author presents the clinical history of 14 patients, from 21 to 48 years of age, 10 men and 4 women, with a final diagnosis of acute epiglottitis who were hospitalized at Gorgas Army Hospital or at the San Fernando Clinic. All the patients had pharyngitis and dysphagia, a few with nasal voice, stridor and difficulty breathing, as the chief complaint. All the patients were initially intubated orally for diagnostic purposes and immediately after nasotracheal intubation was done until the patient improved in 2 or 3 days (one patient remained intubated for 5 days). All patients were kept in the Intensive Care Unit and were treated with Ampicillin and Chloramphenicol IV and lately with a second generation cephalosporin (Cefamandole). The patients allergic to Penicillin were treated with Clindamycin and Chloramphenicol. Corticosteroids were not used in any of the patients. There were no sequelae and none of the patients expired. PMID:1439005

  10. Acute haematogenous osteitis.

    PubMed Central

    Anderson, J R; Orr, J D; Maclean, D A; Scobie, W G

    1980-01-01

    During a 10-year period 217 cases of acute haematogenous osteitis were treated. In 131 patients the diagnosis was confirmed either radiologically or bacteriologically, but in the other 86 the diagnosis was based on clinical examination. Either cloxacillin or lincomycin proved to be effective if given before bacteriological diagnosis. Frequent clinical examination, assessing both local signs and the child's general state, will decide which child requires surgery (which should be reserved for the toxic child, the child with concomitant medical disorders lowering host resistance, and the child who does not respond to, or has a lesion which flares up after, initial conservative treatment). Constant vigilance is required by clinicians looking after children with this disease in order to reduce the disabling long-term sequelae. PMID:7458395

  11. Acute Leukemias in Children

    PubMed Central

    Pai, Mohan K. R.

    1979-01-01

    With combination chemotherapy approximately 50% of children with lymphoblastic leukemia survive for five or more years and it is now realistic to hope for a cure. Development of sophisticated cytochemical and immunological techniques have enabled us to recognize the factors that predispose to treatment failures. The survival in acute non-lymphocytic leukemia continues to be poor despite the introduction of several innovative treatment regimens. Current research is focused on the manipulation of the host-tumor immune response to eradicate the disease by treatment modalities such as immunotherapy and bone marrow transplantation. Since the treatment regimens are becoming more complex, the initial diagnosis and treatment is best carried out at centres specialized in the management of childhood malignancies. ImagesFig. 1Fig. 2Fig. 3 PMID:21297755

  12. [Acute respiratory distress syndrome].

    PubMed

    Estenssoro, Elisa; Dubin, Arnaldo

    2016-01-01

    Acute respiratory distress syndrome (ARDS) is an acute respiratory failure produced by an inflammatory edema secondary to increased lung capillary permeability. This causes alveolar flooding and subsequently deep hypoxemia, with intrapulmonary shunt as its most important underlying mechanism. Characteristically, this alteration is unresponsive to high FIO2 and only reverses with end-expiratory positive pressure (PEEP). Pulmonary infiltrates on CXR and CT are the hallmark, together with decreased lung compliance. ARDS always occurs within a week of exposition to a precipitating factor; most frequently pneumonia, shock, aspiration of gastric contents, sepsis, and trauma. In CT scan, the disease is frequently inhomogeneous, with gravitational infiltrates coexisting with normal-density areas and also with hyperaerated parenchyma. Mortality is high (30-60%) especially in ARDS associated with septic shock and neurocritical diseases. The cornerstone of therapy lies in the treatment of the underlying cause and in the use mechanical ventilation which, if inappropriately administered, can lead to ventilator-induced lung injury. Tidal volume = 6 ml/kg of ideal body weight to maintain an end-inspiratory (plateau) pressure = 30 cm H2O ("protective ventilation") is the only variable consistently associated with decreased mortality. Moderate-to-high PEEP levels are frequently required to treat hypoxemia, yet no specific level or titration strategy has improved outcomes. Recently, the use of early prone positioning in patients with PaO2/FIO2 = 150 was associated with increased survival. In severely hypoxemic patients, it may be necessary to use adjuvants of mechanical ventilation as recruitment maneuvers, pressure-controlled modes, neuromuscular blocking agents, and extracorporeal-membrane oxygenation. Fluid restriction appears beneficial. PMID:27576283

  13. Asthma in adults (acute)

    PubMed Central

    2011-01-01

    Introduction About 10% of adults have suffered an attack of asthma, and up to 5% of these have severe disease that responds poorly to treatment. Patients with severe disease have an increased risk of death, but patients with mild to moderate disease are also at risk of exacerbations. Most guidelines about the management of asthma follow stepwise protocols. This review does not endorse or follow any particular protocol, but presents the evidence about specific interventions. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical question: What are the effects of treatments for acute asthma? We searched: Medline, Embase, The Cochrane Library, and other important databases up to April 2010 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found 100 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review we present information relating to the effectiveness and safety of the following interventions: beta2 agonists (plus ipratropium bromide, pressured metered-dose inhalers, short-acting continuous nebulised, short-acting intermittent nebulised, short-acting iv, and inhaled formoterol); corticosteroids (inhaled); corticosteroids (single oral, combined inhaled, and short courses); education about acute asthma; generalist care; helium–oxygen mixture (heliox); magnesium sulphate (iv and adding isotonic nebulised magnesium to inhaled beta2 agonists); mechanical ventilation; oxygen supplementation (controlled 28% oxygen and controlled 100% oxygen); and specialist care. PMID:21463536

  14. Exercise capacity is not impaired after acute alcohol ingestion: a pilot study.

    PubMed

    Popovic, Dejana; Damjanovic, Svetozar S; Plecas-Solarovic, Bosiljka; Pešić, Vesna; Stojiljkovic, Stanimir; Banovic, Marko; Ristic, Arsen; Mantegazza, Valentina; Agostoni, Piergiuseppe

    2014-08-01

    The usage of alcohol is widespread, but the effects of acute alcohol ingestion on exercise performance and the stress hormone axis are not fully elucidated.We studied 10 healthy white men, nonhabitual drinkers, by Doppler echocardiography at rest, spirometry, and maximal cardiopulmonary exercise test (CPET) in two visits (2-4 days in between), one after administration of 1.5 g/kg ethanol (whisky) diluted at 15% in water, and the other after administration of an equivalent volume of water. Plasma levels of NT-pro-BNP, cortisol, and adrenocorticotropic hormone (ACTH) were also measured 10 min before the test, at maximal effort and at the third minute of recovery. Ethanol concentration was measured from resting blood samples by gas chromatography and it increased from 0.00 ± 0.00 to 1.25 ± 0.54‰ (P < 0.001). Basal echocardiographic and spirometric parameters were normal and remained so after acute alcohol intake, whereas ACTH, cortisol, and NT-pro-BNP nonsignificantly increased in all phases of the test. CPET data suggested a trend toward a slight reduction of exercise performance (peak VO2 = 3008 ± 638 vs. 2900 ± 543 ml/min, ns; peak workload = 269 ± 53 vs. 249 ± 40 W, ns; test duration 13.7 ± 2.2 vs. 13.3 ± 1.7 min, ns; VE/VCO2 22.1 ± 1.4 vs. 23.3 ± 2.9, ns). Ventilatory equivalent for carbon dioxide at rest was higher after alcohol intake (28 ± 2.5 vs. 30.4 ± 3.2, P = 0.039) and maximal respiratory exchange ratio was lower after alcohol intake (1.17 ± 0.02 vs. 1.14 ± 0.04, P = 0.04). In conclusion, we showed that acute alcohol intake in healthy white men is associated with a nonsignificant exercise performance reduction and stress hormone stimulation, with an unchanged exercise metabolism. PMID:25083719

  15. Biomarkers in acute heart failure.

    PubMed

    Mallick, Aditi; Januzzi, James L

    2015-06-01

    The care of patients with acutely decompensated heart failure is being reshaped by the availability and understanding of several novel and emerging heart failure biomarkers. The gold standard biomarkers in heart failure are B-type natriuretic peptide and N-terminal pro-B-type natriuretic peptide, which play an important role in the diagnosis, prognosis, and management of acute decompensated heart failure. Novel biomarkers that are increasingly involved in the processes of myocardial injury, neurohormonal activation, and ventricular remodeling are showing promise in improving diagnosis and prognosis among patients with acute decompensated heart failure. These include midregional proatrial natriuretic peptide, soluble ST2, galectin-3, highly-sensitive troponin, and midregional proadrenomedullin. There has also been an emergence of biomarkers for evaluation of acute decompensated heart failure that assist in the differential diagnosis of dyspnea, such as procalcitonin (for identification of acute pneumonia), as well as markers that predict complications of acute decompensated heart failure, such as renal injury markers. In this article, we will review the pathophysiology and usefulness of established and emerging biomarkers for the clinical diagnosis, prognosis, and management of acute decompensated heart failure.

  16. [Latest advances in acute pancreatitis].

    PubMed

    de-Madaria, Enrique

    2015-09-01

    The present article analyses the main presentations on acute pancreatitis at Digestive Disease Week 2015. Arterial pseudoaneurysm is an uncommon complication of acute pancreatitis (incidence 0.7%) and mortality from this cause is currently anecdotal. Diabetes mellitus has little impact on the clinical course of acute pancreatitis, unlike cirrhosis, which doubles the risk of mortality. Intake of unsaturated fat could be associated with an increased severity of acute pancreatitis and is a confounding factor in studies evaluating the relationship between obesity and morbidity and mortality. PET-CT (positron emission tomography-computed tomography) could be a non-invasive tool to detect infection of collections in acute pancreatitis. Peripancreatic fat necrosis is less frequent than pancreatic fat necrosis and is associated with a better clinical course. If the clinical course is poor, increasing the calibre of the percutaneous drains used in the treatment of infected necrosis can avoid surgery in 20% of patients. The use of low molecular-weight heparin in moderate or severe pancreatitis could be associated with a better clinical course, specifically with a lower incidence of necrosis. In acute recurrent pancreatitis, simvastatin is a promising drug for prophylaxis of new episodes of acute pancreatitis. Nutritional support through a nasogastric tube does not improve clinical course compared with oral nutrition.

  17. Acute supra-therapeutic oral terbutaline administration has no ergogenic effect in non-asthmatic athletes.

    PubMed

    Sanchez, Anthony M J; Borrani, Fabio; Le Fur, Marie Amélie; Le Mieux, Anais; Lecoultre, Virgile; Py, Guillaume; Gernigon, Christophe; Collomp, Katia; Candau, Robin

    2013-02-01

    This study aimed to investigate the effects on a possible improvement in aerobic and anaerobic performance of oral terbutaline (TER) at a supra-therapeutic dose in 7 healthy competitive male athletes. On day 1, ventilatory threshold, maximum oxygen uptake [Formula: see text] and corresponding power output were measured and used to determine the exercise load on days 2 and 3. On days 2 and 3, 8 mg of TER or placebo were orally administered in a double-blind process to athletes who rested for 3 h, and then performed a battery of tests including a force-velocity exercise test, running sprint and a maximal endurance cycling test at Δ50 % (50 % between VT and [Formula: see text]). Lactatemia, anaerobic parameters and endurance performance ([Formula: see text] and time until exhaustion) were raised during the corresponding tests. We found that TER administration did not improve any of the parameters of aerobic performance (p > 0.05). In addition, no change in [Formula: see text] kinetic parameters was found with TER compared to placebo (p > 0.05). Moreover, no enhancement of the force-velocity relationship was observed during sprint exercises after TER intake (p > 0.05) and, on the contrary, maximal strength decreased significantly after TER intake (p < 0.05) but maximal power remained unchanged (p > 0.05). In conclusion, oral acute administration of TER at a supra-therapeutic dose seems to be without any relevant ergogenic effect on anaerobic and aerobic performances in healthy athletes. However, all participants experienced adverse side effects such as tremors. PMID:22767151

  18. [Cerebrolysin for acute ischemic stroke].

    PubMed

    iganshina, L E; Abakumova, T R

    2013-01-01

    The review discusses existing evidence of benefits and risks of cerebrolysin--a mixture of low-molecular-weight peptides and amino acids derived from pigs' brain tissue with proposed neuroprotective and neurotrophic properties, for acute ischemic stroke. The review presents results of systematic search and analysis of randomised clinical trials comparing cerebrolysin with placebo in patients with acute ischemic stroke. Only one trial was selected as meeting quality criteria. No difference in death and adverse events between cerebrolysin and placebo was established. The authors conclude about insufficiency of evidence to evaluate the effect of cerebrolysin on survival and dependency in people with acute ischemic stroke.

  19. Early management of acute pancreatitis.

    PubMed

    Schepers, Nicolien J; Besselink, Marc G H; van Santvoort, Hjalmar C; Bakker, Olaf J; Bruno, Marco J

    2013-10-01

    Acute pancreatitis is the most common gastro-intestinal indication for acute hospitalization and its incidence continues to rise. In severe pancreatitis, morbidity and mortality remains high and is mainly driven by organ failure and infectious complications. Early management strategies should aim to prevent or treat organ failure and to reduce infectious complications. This review addresses the management of acute pancreatitis in the first hours to days after onset of symptoms, including fluid therapy, nutrition and endoscopic retrograde cholangiography. This review also discusses the recently revised Atlanta classification which provides new uniform terminology, thereby facilitating communication regarding severity and complications of pancreatitis.

  20. [Acute heart failure: acute cardiogenic pulmonary edema and cardiogenic shock].

    PubMed

    Sánchez Marteles, Marta; Urrutia, Agustín

    2014-03-01

    Acute cardiogenic pulmonary edema and cardiogenic shock are two of the main forms of presentation of acute heart failure. Both entities are serious, with high mortality, and require early diagnosis and prompt and aggressive management. Acute pulmonary edema is due to the passage of fluid through the alveolarcapillary membrane and is usually the result of an acute cardiac episode. Correct evaluation and clinical identification of the process is essential in the management of acute pulmonary edema. The initial aim of treatment is to ensure hemodynamic stability and to correct hypoxemia. Other measures that can be used are vasodilators such as nitroglycerin, loop diuretics and, in specific instances, opioids. Cardiogenic shock is characterized by sustained hypoperfusion, pulmonary wedge pressure > 18 mmHg and a cardiac index < 2.2l/min/m(2). The process typically presents with hypotension (systolic blood pressure < 90 mmHg or a decrease in mean arterial pressure > 30 mmHg) and absent or reduced diuresis (< 0.5 ml/kg/h). The most common cause is left ventricular failure due to acute myocardial infarction. Treatment consists of general measures to reverse acidosis and hypoxemia, as well as the use of vasopressors and inotropic drugs. Early coronary revascularization has been demonstrated to improve survival in shock associated with ischaemic heart disease.

  1. [Ascites and acute kidney injury].

    PubMed

    Piano, Salvatore; Tonon, Marta; Angeli, Paolo

    2016-07-01

    Ascites is the most common complication of cirrhosis. Ascites develops as a consequence of an abnormal splanchnic vasodilation with reduction of effecting circulating volume and activation of endogenous vasoconstrictors system causing salt and water retention. Patients with ascites have a high risk to develop further complications of cirrhosis such as hyponatremia, spontaneous bacterial peritonitis and acute kidney injury resulting in a poor survival. In recent years, new studies helped a better understanding of the pathophysiology of ascites and acute kidney injury in cirrhosis. Furthermore, new diagnostic criteria have been proposed for acute kidney injury and hepatorenal syndrome and a new algorithm for their management has been recommended with the aim of an early diagnosis and treatment. Herein we will review the current knowledge on the pathophysiology, diagnosis and treatment of ascites and acute kidney injury in patients with cirrhosis and we will identify the unmet needs that should be clarified in the next years. PMID:27571467

  2. Acute intestinal anisakiasis: CT findings.

    PubMed

    Ozcan, H N; Avcu, S; Pauwels, W; Mortelé, K J; De Backer, A I

    2012-09-01

    Small bowel anisakiasis is a relatively uncommon disease that results from consumption of raw or insufficiently pickled, salted, smoked, or cooked wild marine fish infected with Anisakis larvae. We report a case of intestinal anisakiasis in a 63-year-old woman presenting with acute onset of abdominal complaints one day after ingestion of raw wild-caught herring from the Northsea. Computed tomography (CT) scanning demonstrated thickening of the distal small bowel wall, mucosa with hyperenhancement, mural stratification, fluid accumulation within dilated small-bowel loops and hyperemia of mesenteric vessels. In patients with a recent history of eating raw marine fish presenting with acute onset of abdominal complaints and CT features of acute small bowel inflammation the possibility of anisakiasis should be considered in the differential diagnosis of acute abdominal syndromes.

  3. Biomarkers in acute lung injury.

    PubMed

    Mokra, Daniela; Kosutova, Petra

    2015-04-01

    Acute respiratory distress syndrome (ARDS) and its milder form acute lung injury (ALI) may result from various diseases and situations including sepsis, pneumonia, trauma, acute pancreatitis, aspiration of gastric contents, near-drowning etc. ALI/ARDS is characterized by diffuse alveolar injury, lung edema formation, neutrophil-derived inflammation, and surfactant dysfunction. Clinically, ALI/ARDS is manifested by decreased lung compliance, severe hypoxemia, and bilateral pulmonary infiltrates. Severity and further characteristics of ALI/ARDS may be detected by biomarkers in the plasma and bronchoalveolar lavage fluid (or tracheal aspirate) of patients. Changed concentrations of individual markers may suggest injury or activation of the specific types of lung cells-epithelial or endothelial cells, neutrophils, macrophages, etc.), and thereby help in diagnostics and in evaluation of the patient's clinical status and the treatment efficacy. This chapter reviews various biomarkers of acute lung injury and evaluates their usefulness in diagnostics and prognostication of ALI/ARDS.

  4. Ultrasonography in acute gallbladder perforation.

    PubMed

    Soiva, M; Pamilo, M; Päivänsalo, M; Taavitsainen, M; Suramo, I

    1988-01-01

    The files of patients with acute cholecystitis from two large university hospitals from the years 1978-1985 were employed to find the cases with acute gallbladder perforation for this study. Only those patients (n = 9) were selected for the analysis of sonographic signs of acute gallbladder perforation who had less than 48 hours of symptoms before sonography, and were operated upon within 24 hours of the sonography. Patients (n = 10) with non-complicated acute cholecystitis and identical in regard to the duration of the symptoms and the timing of the sonography and the operation formed a control group. The sonographic findings in patients with gallbladder perforation were pericholecystic fluid collections, free peritoneal fluid, disappearance of the gallbladder wall echoes, focal highly echogenic areas with acoustic shadows in the gallbladder, and an inhomogeneous, generally echo-poor gallbladder wall. PMID:2964842

  5. Causes of acute bronchitis (image)

    MedlinePlus

    ... of the bronchial tubes, the part of the respiratory system that leads into the lungs. Acute bronchitis has a sudden onset and usually appears after a respiratory infection, such as a cold, and can be ...

  6. Inflammatory mediators in acute pancreatitis.

    PubMed

    Bhatia, M; Brady, M; Shokuhi, S; Christmas, S; Neoptolemos, J P; Slavin, J

    2000-02-01

    Inflammatory mediators play a key role in acute pancreatitis and the resultant multiple organ dysfunction syndrome, which is the primary cause of death in this condition. Recent studies have confirmed the critical role played by inflammatory mediators such as TNF-alpha, IL-1beta, IL-6, IL-8, PAF, IL-10, C5a, ICAM-1, and substance P. The systemic effects of acute pancreatitis have many similarities to those of other conditions such as septicaemia, severe burns, and trauma. The delay between the onset of inflammation in the pancreas and the development of the systemic response makes acute pancreatitis an ideal experimental and clinical model with which to study the role of inflammatory mediators and to test novel therapies. Elucidation of the key mediators involved in the pathogenesis of acute pancreatitis will facilitate the development of clinically effective anti-inflammatory therapy.

  7. [Ascites and acute kidney injury].

    PubMed

    Piano, Salvatore; Tonon, Marta; Angeli, Paolo

    2016-07-01

    Ascites is the most common complication of cirrhosis. Ascites develops as a consequence of an abnormal splanchnic vasodilation with reduction of effecting circulating volume and activation of endogenous vasoconstrictors system causing salt and water retention. Patients with ascites have a high risk to develop further complications of cirrhosis such as hyponatremia, spontaneous bacterial peritonitis and acute kidney injury resulting in a poor survival. In recent years, new studies helped a better understanding of the pathophysiology of ascites and acute kidney injury in cirrhosis. Furthermore, new diagnostic criteria have been proposed for acute kidney injury and hepatorenal syndrome and a new algorithm for their management has been recommended with the aim of an early diagnosis and treatment. Herein we will review the current knowledge on the pathophysiology, diagnosis and treatment of ascites and acute kidney injury in patients with cirrhosis and we will identify the unmet needs that should be clarified in the next years.

  8. Acute upper airway infections.

    PubMed

    West, J V

    2002-01-01

    Upper respiratory tract infections are common and important. Although rarely fatal, they are a source of significant morbidity and carry a considerable economic burden. Numerous therapies for the common cold have no effect on symptoms or outcome. Complications such as cough are not improved by over-the-counter preparations, while labelling cough alone as a symptom of asthma may result in unnecessary use of inhaled steroid treatment. Clinical presentation of sore throat does not accurately predict whether the infection is viral or bacterial, while throat culture and rapid antigen tests do not significantly change prescribing practice. Antibiotics have only a limited place in the management of recurrent sore throat due to group A beta-haemolytic streptococcal infection. Routine use of antibiotics in upper respiratory infection enhances parent belief in their effectiveness and increases the likelihood of future consultation in primary care for minor self-limiting illness. Respiratory viruses play a major role in the aetiology of acute otitis media (AOM); prevention includes the use of influenza or RSV vaccination, in addition to reducing other risk factors such as early exposure to respiratory viruses in day-care settings and to environmental tobacco smoke. The use of ventilation tubes (grommets) in secretory otitis media (SOM) remains controversial with conflicting data on developmental outcome and quality of life in young children. New conjugate pneumococcal vaccines appear safe in young children and prevent 6-7% of clinically diagnosed AOM.

  9. Acute Diarrhea in Children.

    PubMed

    Radlović, Nedeljko; Leković, Zoran; Vuletić, Biljana; Radlović, Vladimir; Simić, Dušica

    2015-01-01

    Acute diarrhea (AD) is the most frequent gastroenterological disorder, and the main cause of dehydration in childhood. It is manifested by a sudden occurrence of three or more watery or loose stools per day lasting for seven to 10 days, 14 days at most. It mainly occurs in children until five years of age and particularly in neonates in the second half-year and children until the age of three years. Its primary causes are gastrointestinal infections, viral and bacterial, and more rarely alimentary intoxications and other factors. As dehydration and negative nutritive balance are the main complications of AD, it is clear that the compensation of lost body fluids and adequate diet form the basis of the child's treatment. Other therapeutic measures, except antipyretics in high febrility, antiparasitic drugs for intestinal lambliasis, anti-amebiasis and probiotics are rarely necessary. This primarily regards uncritical use of antibiotics and intestinal antiseptics in the therapy of bacterial diarrhea.The use of antiemetics, antidiarrhetics and spasmolytics is unnecessary and potentially risky, so that it is not recommended for children with AD. PMID:26946776

  10. Traumatic stress in acute leukemia

    PubMed Central

    Rodin, Gary; Yuen, Dora; Mischitelle, Ashley; Minden, Mark D; Brandwein, Joseph; Schimmer, Aaron; Marmar, Charles; Gagliese, Lucia; Lo, Christopher; Rydall, Anne; Zimmermann, Camilla

    2013-01-01

    Objective Acute leukemia is a condition with an acute onset that is associated with considerable morbidity and mortality. However, the psychological impact of this life-threatening condition and its intensive treatment has not been systematically examined. In the present study, we investigate the prevalence and correlates of post-traumatic stress symptoms in this population. Methods Patients with acute myeloid, lymphocytic, and promyelocytic leukemia who were newly diagnosed, recently relapsed, or treatment failures were recruited at a comprehensive cancer center in Toronto, Canada. Participants completed the Stanford Acute Stress Reaction Questionnaire, Memorial Symptom Assessment Scale, CARES Medical Interaction Subscale, and other psychosocial measures. A multivariate regression analysis was used to assess independent predictors of post-traumatic stress symptoms. Results Of the 205 participants, 58% were male, mean age was 50.1 ± 15.4 years, 86% were recently diagnosed, and 94% were receiving active treatment. The mean Stanford Acute Stress Reaction Questionnaire score was 30.2 ± 22.5, with 27 of 200 (14%) patients meeting criteria for acute stress disorder and 36 (18%) for subsyndromal acute stress disorder. Post-traumatic stress symptoms were associated with more physical symptoms, physical symptom distress, attachment anxiety, and perceived difficulty communicating with health-care providers, and poorer spiritual well-being (all p <0.05). Conclusions The present study demonstrates that clinically significant symptoms of traumatic stress are common in acute leukemia and are linked to the degree of physical suffering, to satisfaction with relationships with health-care providers, and with individual psychological characteristics. Longitudinal study is needed to determine the natural history, but these findings suggest that intervention may be indicated to alleviate or prevent traumatic stress in this population. PMID:22081505

  11. [Correlation between hyperamylasemia and acute pancreatitis].

    PubMed

    Monaco, R; Durante, E; Pampolini, M; Tioli, P

    1981-05-31

    It is often difficult to differentiate acute pancreatitis (A.P.) from some other acute abdominal diseases, when there is an elevated serum amylase. In contrast, the renal clearance of amylase, expressed as a percentage of creatinine clearance, can separate patients with A.P. from patients with acute colecistitis, common duct stone without pancreatitis, hyperamylasemia after biliary surgery, acute peptic ulcer and acute salivary diseases.

  12. Perioperative acute kidney injury.

    PubMed

    Goren, O; Matot, I

    2015-12-01

    Perioperative acute kidney injury (AKI) is not uncommon and is associated with considerable morbidity and mortality. Recently, several definition systems for AKI were proposed, incorporating both small changes of serum creatinine and urinary output reduction as diagnostic criteria. Novel biomarkers are under investigation as fast and accurate predictors of AKI. Several special considerations regarding the risk of AKI are of note in the surgical patient. Co-morbidities are important risk factors for AKI. The surgery in itself, especially emergency and major surgery in the critically ill, is associated with a high incidence of AKI. Certain types of surgeries, such as cardiac and transplantation surgeries, require special attention because they carry higher risk of AKI. Nephrotoxic drugs, contrast dye, and diuretics are commonly used in the perioperative period and are responsible for a significant amount of in-hospital AKI. Before surgery, the anaesthetist is required to identify patients at risk of AKI, optimize anaemia, and treat hypovolaemia. During surgery, normovolaemia is of utmost importance. Additionally, the surgical and anaesthesia team is advised to use measures to reduce blood loss and avoid unnecessary blood transfusion. Hypotension should be avoided because even short periods of mean arterial pressure <55-60 mm Hg carry a risk of postoperative AKI. Higher blood pressures are probably required for hypertensive patients. Urine output can be reduced significantly during surgery and is unrelated to perioperative renal function. Thus, fluids should not be given in excess for the sole purpose of avoiding or treating oliguria. Use of hydroxyethyl starch needs to be reconsidered. Recent evidence indicates a beneficial effect of administering low-chloride solutions. PMID:26658199

  13. Hyperoxic Acute Lung Injury

    PubMed Central

    Kallet, Richard H; Matthay, Michael A

    2013-01-01

    Prolonged breathing of very high FIO2 (FIO2 ≥ 0.9) uniformly causes severe hyperoxic acute lung injury (HALI) and, without a reduction of FIO2, is usually fatal. The severity of HALI is directly proportional to PO2 (particularly above 450 mm Hg, or an FIO2 of 0.6) and exposure duration. Hyperoxia produces extraordinary amounts of reactive O2 species that overwhelms natural antioxidant defenses and destroys cellular structures through several pathways. Genetic predisposition has been shown to play an important role in HALI among animals, and some genetics-based epidemiologic research suggests that this may be true for humans as well. Clinically, the risk of HALI likely occurs when FIO2exceeds 0.7, and may become problematic when FIO2 exceeds 0.8 for an extended period of time. Both high-stretch mechanical ventilation and hyperoxia potentiate lung injury and may promote pulmonary infection. During the 1960s, confusion regarding the incidence and relevance of HALI largely reflected such issues as the primitive control of FIO2, the absence of PEEP, and the fact that at the time both ALI and ventilator-induced lung injury were unknown. The advent of PEEP and precise control over FIO2, as well as lung-protective ventilation, and other adjunctive therapies for severe hypoxemia, has greatly reduced the risk of HALI for the vast majority of patients requiring mechanical ventilation in the 21st century. However, a subset of patients with very severe ARDS requiring hyperoxic therapy is at substantial risk for developing HALI, therefore justifying the use of such adjunctive therapies. PMID:23271823

  14. Acute Migraine Treatment in Adults.

    PubMed

    Becker, Werner J

    2015-06-01

    There are many options for acute migraine attack treatment, but none is ideal for all patients. This study aims to review current medical office-based acute migraine therapy in adults and provides readers with an organized approach to this important facet of migraine treatment. A general literature review includes a review of several recent published guidelines. Acetaminophen, 4 nonsteroidal anti-inflammatory drugs (NSAIDs) (ibuprofen, acetylsalicylic acid [ASA], naproxen sodium, and diclofenac potassium), and 7 triptans (almotriptan, eletriptan, frovatriptan, naratriptan, rizatriptan, sumatriptan, and zolmitriptan) have good evidence for efficacy and form the core of acute migraine treatment. NSAID-triptan combinations, dihydroergotamine, non-opioid combination analgesics (acetaminophen, ASA, and caffeine), and several anti-emetics (metoclopramide, domperidone, and prochlorperazine) are additional evidence-based options. Opioid containing combination analgesics may be helpful in specific patients, but should not be used routinely. Clinical features to be considered when choosing an acute migraine medication include usual headache intensity, usual rapidity of pain intensity increase, nausea, vomiting, degree of disability, patient response to previously used medications, history of headache recurrence with previous attacks, and the presence of contraindications to specific acute medications. Available acute medications can be organized into 4 treatment strategies, including a strategy for attacks of mild to moderate severity (strategy one: acetaminophen and/or NSAIDs), a triptan strategy for patients with severe attacks and for attacks not responding to strategy one, a refractory attack strategy, and a strategy for patients with contraindications to vasoconstricting drugs. Acute treatment of migraine attacks during pregnancy, lactation, and for patients with chronic migraine is also discussed. In chronic migraine, it is particularly important that medication

  15. Acute proliferative retrolental fibroplasia: multivariate risk analysis.

    PubMed Central

    Flynn, J T

    1983-01-01

    This study has presented a two-way analysis of a data set consisting of demographic, diagnostic, and therapeutic variables against the risk of occurrence of APRLF and its location in the retina in a population of 639 infants in birthweights ranging from 600 to 1500 gm. Univariate and multivariate risk analysis techniques were employed to analyze the data. As established from previous studies, birthweight was a powerful predictor of the outcome variable. Oxygen therapy as defined and quantified in this study was not. Duration of ventilatory assistance did seem associated. The population was not uniform. Infants below 1000 gm birthweight had such a high incidence of APRLF that no other exogenous risk factors seemed of significance. Above 1000 gm birthweight, certain factors, particularly duration of ventilation, seemed of predictive strength and significance. Images FIGURE 5 A FIGURE 5 B FIGURE 4 A FIGURE 4 B PMID:6689564

  16. Genetically Modified T-cell Immunotherapy in Treating Patients With Relapsed or Refractory Acute Myeloid Leukemia

    ClinicalTrials.gov

    2016-08-10

    Adult Acute Myeloid Leukemia in Remission; Donor; Early Relapse of Acute Myeloid Leukemia; Late Relapse of Acute Myeloid Leukemia; Recurrent Adult Acute Myeloid Leukemia; Secondary Acute Myeloid Leukemia

  17. Acute kidney injury in acute liver failure: a review.

    PubMed

    Moore, Joanna K; Love, Eleanor; Craig, Darren G; Hayes, Peter C; Simpson, Kenneth J

    2013-11-01

    Acute liver failure is a rare and often devastating condition consequent on massive liver cell necrosis that frequently affects young, previously healthy individuals resulting in altered cognitive function, coagulopathy and peripheral vasodilation. These patients frequently develop concurrent acute kidney injury (AKI). This abrupt and sustained decline in renal function, through a number of pathogenic mechanisms such as renal hypoperfusion, direct drug-induced nephrotoxicity or sepsis/systemic inflammatory response contributes to increased morbidity and is strongly associated with a worse prognosis. Improved understanding of the pathophysiology AKI in the context of acute liver failure may be beneficial in a number of areas; the development of new and sensitive biomarkers of renal dysfunction, refining prognosis and organ allocation, and ultimately leading to the development of novel treatment strategies, these issues are discussed in more detail in this expert review.

  18. [Tomodensitometry of severe acute pancreatitis].

    PubMed

    Frija, J; Abanou, A; Viandier, A; Laval-Jeantet, M

    1983-01-01

    90 computed tomographic examinations were performed to 57 patients referred at Hospital Saint-Louis for an acute pancreatitis. 32 patients were operated or autopsied. Among these 32 patients, 19 patients had 21 examinations before surgery or autopsy; the other 13 patients had their computed tomographic examinations after one or more surgical procedures. During a severe acute pancreatitis the pancreas is always large either locally or diffusely. A pancreatic reaction is visible around and possibly at distance of the pancreas. When extraluminal gas is visible (3/5) it signifies gangrenous pancreatitis but it is necessary to eliminate a digestive fistulous tract and/or a communication between a pseudocyst and the digestive tract. Except gangrenous it is not possible to precise the nature of pancreatic reaction. The diagnosis of pseudocyst was easy 9/10, difficult 1/10; we did a false positive diagnosis of pseudocyst. Computed tomography and ultrasounds were compared in ten patients for the search of gallbladder lithiasis. Computed tomography can show large and small (2/4) biliary calculus in the gallbladder that cannot be shown by ultrasounds. A normal pancreas in a normal retroperitoneal space exclude the diagnosis of a severe acute pancreatitis. CT aspects of acute pancreatitis must be considered as a good diagnostic test of an acute pancreatitis.

  19. Natural course of acute pancreatitis.

    PubMed

    Beger, H G; Rau, B; Mayer, J; Pralle, U

    1997-02-01

    Acute pancreatitis comprises, in terms of clinical, pathologic, biochemical, and bacteriologic data, four entities. Interstitial edematous pancreatitis and necrotizing pancreatitis are the most frequent clinical manifestations; pancreatic pseudocyst and pancreatic abscess are late complications after necrotizing pancreatitis, developing after 3 to 5 weeks. Determinants of the natural course of acute pancreatitis are pancreatic parenchymal necrosis, extrapancreatic retroperitoneal fatty tissue necrosis, biologically active compounds in pancreatic ascites, and infection of necrosis. Early in the course of acute pancreatitis multiple organ failure is the consequence of various inflammatory mediators that are released from the inflammatory process and from activated leukocytes attracted by pancreatic injury. During the late course, starting the second week, local and systemic septic complications are dominant. Around 80% of deaths in acute pancreatitis are caused by septic complications. The infection of pancreatic necrosis occurs in 8% to 12% of acute pancreatitis and in 30% to 40% of patients with necrotizing pancreatitis. Bacteriologic analysis of intraoperative smears and aspirates reveals predominantly gram-negative germs deriving from the intestine, most frequently Escherichia coli. It has been confirmed that after necrotizing pancreatitis a considerable large group of patients suffer long-lasting exocrine and endocrine insufficiency.

  20. Comparison of occlusion pressure and ventilatory responses.

    PubMed Central

    Lederer, D H; Altose, M D; Kelsen, S G; Cherniack, N S

    1977-01-01

    The airway pressure 100 msec after the onset of an inspiratory effort against a closed airway (P100, occlusion pressure) is theoretically a more accurate index of respiratory neuron motor output than ventilation. Occlusion pressure and ventilation responses to hypercapnia were compared in repeated trials in 10 normal subjects while in the seated and supine positions. During progressive hypercapnia changes in P100 were also compared to changes in tidal volume and inspiratory airflow. These studies show that occlusion pressure increases linearly with hypercapnia in both sitting and supine subjects. Changing from the seated to the supine position, or vice versa, had no significant effect on either ventilation or occlusion pressure responses to CO2. Correlations between P100 and ventilation or airflow rate were significantly higher than correlations between P100 and tidal volume or breathing frequency. Intermittent random airway occlusion had no effect on either ventilation or pattern of breathing during hypercapnia. Occlusion pressure responses were no less variable than ventilation responses in groups of subjects whether studied seated or supine. However, maintenance of a constant moderate breathing frequency (20 breaths per minute) reduced the interindividual variability in ventilation and occlusion pressure responses to hypercapnia. PMID:867336

  1. Perioperative Ventilatory Management in Cardiac Surgery

    PubMed Central

    Fischer, Marc-Olivier; Courteille, Benoît; Guinot, Pierre-Grégoire; Dupont, Hervé; Gérard, Jean-Louis; Hanouz, Jean-Luc; Lorne, Emmanuel

    2016-01-01

    Abstract Protective ventilation is associated with a lower incidence of pulmonary complications. However, there are few published data on routine pulmonary management in adult cardiac surgery. The present study's primary objective was to survey pulmonary management in this high-risk population, as practiced by anesthesiologists in France. All 460 registered France-based cardiac anesthesiologists were invited (by e-mail) to participate in an online survey in January–February 2015. The survey's questionnaire was designed to assess current practice in pre-, per-, and postoperative pulmonary management. In all, 198 anesthesiologists (43% of those invited) participated in the survey. Other than during the cardiopulmonary bypass (CPB) per se, 179 anesthesiologists (91% of respondees) [95% confidence interval (CI): 87–95] used a low-tidal-volume approach (6–8 mL/kg), whereas techniques based on positive end-expiratory pressure and recruitment maneuvers vary greatly from 1 anesthesiologist to another. During CPB, 104 (53%) [95% CI: 46–60] anesthesiologists withdrew mechanical ventilation (with disconnection, in some cases) and 97 (49%) [95% CI: 42–56] did not prescribe positive end-expiratory pressure. One hundred sixty-five (83%) [95% CI: 78–88] anesthesiologists stated that a written protocol for peroperative pulmonary management was not available. Twenty (10%) [95% CI: 6–14] and 11 (5%) [95% CI: 2–8] anesthesiologists stated that they did use protocols for ventilator use and recruitment maneuvers, respectively. The preoperative period (pulmonary examinations and prescription of additional assessments) and the postoperative period (extubation, and noninvasive ventilation) periods vary greatly from 1 anesthesiologist to another. The great majority of French cardiac anesthesiologists use a low tidal volume during cardiac surgery (other than during CPB per se). However, pulmonary management procedures varied markedly from 1 anesthesiologist to another. There is a clear need for large clinical studies designed to identify best practice in pulmonary management. PMID:26945353

  2. The ventilatory effect of external oscillation.

    PubMed

    Isabey, D; Piquet, J

    1989-01-01

    High frequency ventilation (HFV) may be achieved by external oscillation (external HFV) applied around the chest wall (HFCWO) in large animals and humans, or over the entire body (HFBSO) in small animals, instead of being applied via the trachea (internal HFV). We present a synthesis of the results obtained with external HFV in both normal and bronchoconstricted subjects. Whereas external and internal HFV were found to be equivalent in terms of gas exchange in normal rats, external HFV was found to have a beneficial effect in bronchoconstricted rabbits, but internal HFV did not. From the frequency-oscillatory tidal volume relationship determined in normocapnic rabbits, HFBSO at 5 Hz was found to be the optimal frequency at which to ventilate with tidal volumes close to the dead space volume, and which was also shown to be the optimal volume to obtain normocapnia. Moreover, 5 Hz oscillations (HFCWO) at 20 ml and 40 ml superimposed on tidal breathing accelerated nitrogen washout, i.e., gas exchange in normal humans. Unfortunately, only oscillations with much smaller volumes (5-10 ml) were obtainable in COPD patients. Nevertheless, they produced a clear change in breathing pattern associated with a slight improvement in gas exchange and a potentially positive effect on inspiratory muscle fatigue. These results support the concept that non-invasive external HFV technique may be of use in assisting ventilation in bronchoconstricted subjects and may possibly replace conventional controlled ventilation, at least in subjects with high lung compliance, such as babies, neonates and normal adults.

  3. Endoscopic Treatment of Recurrent Acute Pancreatitis and Smoldering Acute Pancreatitis.

    PubMed

    Das, Rohit; Yadav, Dhiraj; Papachristou, Georgios I

    2015-10-01

    Recurrent acute pancreatitis (RAP) is a challenging condition that can lead to chronic pancreatitis and long-term morbidity. Etiology-based treatment can potentially have an impact on the natural history of RAP and its progression to chronic pancreatitis. In cases of divisum-associated RAP and idiopathic RAP, several studies have been performed to evaluate the efficacy of endoscopic therapy in alleviation of symptoms and frequency of AP events. This review discusses the literature available on these topic as well as touching on the role of endoscopic therapy in smoldering acute pancreatitis.

  4. Decitabine, Cytarabine, and Daunorubicin Hydrochloride in Treating Patients With Acute Myeloid Leukemia

    ClinicalTrials.gov

    2016-07-20

    Adult Acute Basophilic Leukemia; Adult Acute Eosinophilic Leukemia; Adult Acute Monoblastic Leukemia; Adult Acute Monocytic Leukemia; Adult Acute Myeloid Leukemia With Maturation; Adult Acute Myeloid Leukemia With t(9;11)(p22;q23); MLLT3-MLL; Adult Acute Myeloid Leukemia Without Maturation; Adult Acute Myelomonocytic Leukemia; Alkylating Agent-Related Acute Myeloid Leukemia; Secondary Acute Myeloid Leukemia; Untreated Adult Acute Myeloid Leukemia

  5. Autophagy in acute brain injury.

    PubMed

    Galluzzi, Lorenzo; Bravo-San Pedro, José Manuel; Blomgren, Klas; Kroemer, Guido

    2016-08-01

    Autophagy is an evolutionarily ancient mechanism that ensures the lysosomal degradation of old, supernumerary or ectopic cytoplasmic entities. Most eukaryotic cells, including neurons, rely on proficient autophagic responses for the maintenance of homeostasis in response to stress. Accordingly, autophagy mediates neuroprotective effects following some forms of acute brain damage, including methamphetamine intoxication, spinal cord injury and subarachnoid haemorrhage. In some other circumstances, however, the autophagic machinery precipitates a peculiar form of cell death (known as autosis) that contributes to the aetiology of other types of acute brain damage, such as neonatal asphyxia. Here, we dissect the context-specific impact of autophagy on non-infectious acute brain injury, emphasizing the possible therapeutic application of pharmacological activators and inhibitors of this catabolic process for neuroprotection. PMID:27256553

  6. Biochemical markers of acute pancreatitis.

    PubMed

    Matull, W R; Pereira, S P; O'Donohue, J W

    2006-04-01

    Serum amylase remains the most commonly used biochemical marker for the diagnosis of acute pancreatitis, but its sensitivity can be reduced by late presentation, hypertriglyceridaemia, and chronic alcoholism. Urinary trypsinogen-2 is convenient, of comparable diagnostic accuracy, and provides greater (99%) negative predictive value. Early prediction of the severity of acute pancreatitis can be made by well validated scoring systems at 48 hours, but the novel serum markers procalcitonin and interleukin 6 allow earlier prediction (12 to 24 hours after admission). Serum alanine transaminase >150 IU/l and jaundice suggest a gallstone aetiology, requiring endoscopic retrograde cholangiopancreatography. For obscure aetiologies, serum calcium and triglycerides should be measured. Genetic polymorphisms may play an important role in "idiopathic" acute recurrent pancreatitis.

  7. Acute Stroke Imaging Research Roadmap

    PubMed Central

    Wintermark, Max; Albers, Gregory W.; Alexandrov, Andrei V.; Alger, Jeffry R.; Bammer, Roland; Baron, Jean-Claude; Davis, Stephen; Demaerschalk, Bart M.; Derdeyn, Colin P.; Donnan, Geoffrey A.; Eastwood, James D.; Fiebach, Jochen B.; Fisher, Marc; Furie, Karen L.; Goldmakher, Gregory V.; Hacke, Werner; Kidwell, Chelsea S.; Kloska, Stephan P.; Köhrmann, Martin; Koroshetz, Walter; Lee, Ting-Yim; Lees, Kennedy R.; Lev, Michael H.; Liebeskind, David S.; Ostergaard, Leif; Powers, William J.; Provenzale, James; Schellinger, Peter; Silbergleit, Robert; Sorensen, Alma Gregory; Wardlaw, Joanna; Wu, Ona; Warach, Steven

    2009-01-01

    The recent “Advanced Neuroimaging for Acute Stroke Treatment” meeting on September 7 and 8, 2007 in Washington DC, brought together stroke neurologists, neuroradiologists, emergency physicians, neuroimaging research scientists, members of the National Institute of Neurological Disorders and Stroke (NINDS), the National Institute of Biomedical Imaging and Bioengineering (NIBIB), industry representatives, and members of the US Food and Drug Administration (FDA) to discuss the role of advanced neuroimaging in acute stroke treatment. The goals of the meeting were to assess state-of-the-art practice in terms of acute stroke imaging research and to propose specific recommendations regarding: (1) the standardization of perfusion and penumbral imaging techniques, (2) the validation of the accuracy and clinical utility of imaging markers of the ischemic penumbra, (3) the validation of imaging biomarkers relevant to clinical outcomes, and (4) the creation of a central repository to achieve these goals. The present article summarizes these recommendations and examines practical steps to achieve them. PMID:18477656

  8. Update on acute rheumatic fever

    PubMed Central

    Madden, Sharen; Kelly, Len

    2009-01-01

    Abstract OBJECTIVE To remind physicians who work with aboriginal populations of the ongoing prevalence of acute rheumatic fever and to review the recent evidence on presentation, treatment, and secondary prophylaxis. SOURCES OF INFORMATION The Cochrane Database of Systematic Reviews, MEDLINE, and EMBASE were searched from 1996 to 2007 with a focus on prevention, epidemiology, and disease management. Case series data from medical records at the Sioux Lookout Meno Ya Win Health Centre in Ontario were also used. MAIN MESSAGE Acute rheumatic fever is still a clinical entity in aboriginal communities in northwest Ontario. Identification, treatment, and secondary prophylaxis are necessary. CONCLUSION Acute rheumatic fever is not a forgotten disease and still exists in remote areas of Canada. PMID:19439697

  9. Acute disseminated encephalomyelitis (ADEM) following a H3N3 parainfluenza virus infection in a pregnant asthmatic woman with respiratory failure

    PubMed Central

    Zeb, Qaiser; Alegria, Ana

    2014-01-01

    This case report relates to a 31-year-old pregnant woman, asthmatic, admitted to the intensive care unit with respiratory failure, secondary to a viral community-acquired pneumonia. A type 3 (H3N3) parainfluenza virus RNA was isolated in her throat swab. The patient developed neurological symptoms (behavioural changes, irritability, agitation and impaired consciousness) while being weaned off sedation and ventilatory support. Cerebrospinal fluid was clear with an opening pressure of 26 cm H2O. Brain MRI showed features compatible with acute disseminated encephalomyelitis. Immune screen and EEG were normal. She was treated with intravenous methylprednisolone followed by oral prednisolone. The patient made an almost full neurological recovery within 4 weeks after starting on steroids. The patient delivered a healthy baby at 38 weeks gestation. This case highlights the importance to keep in mind rare conditions that need early recognition and prompt treatment. Brain MRI is the key to early diagnosis and treatment. PMID:25281245

  10. Acute kidney injury in children.

    PubMed

    Merouani, A; Flechelles, O; Jouvet, P

    2012-04-01

    Acute kidney injury (AKI) affects 5% of critically ill hospitalized children and is a risk factor for increased morbidity and mortality. The current review focuses on new definitions of acute kidney injury, standardized to reflect the entire spectrum of the disease, as well as on ongoing research to identify early biomarkers of kidney injury. Its also provides an overview of current practice and available therapies, with emphasis on new strategies for the prevention and pharmacological treatment of diarrhea-associated hemolytic uremic syndrome. Furthermore, a decision-making algorithm is presented for the use of renal replacement therapies in critically ill children with AKI. PMID:22495187

  11. [Pregnancy and acute ischemic stroke].

    PubMed

    Bereczki, Dániel

    2016-05-15

    Pregnancy-related ischemic strokes play an important role in both maternal and fetal morbidity and mortality. Changes in hemostaseology and hemodynamics as well as risk factors related to or independent from pregnancy contribute to the increased stroke-risk during gestation and the puerperium. Potential teratogenic effects make diagnostics, acute therapy and prevention challenging. Because randomized, controlled trials are not available, a multicenter registry of patients with gestational stroke would be desirable. Until definite guidelines emerge, management of acute ischemic stroke during pregnancy remains individual, involving experts and weighing the risks and benefits.

  12. Nutrition support in acute pancreatitis.

    PubMed

    McClave, Stephen A

    2007-03-01

    The benefit of early enteral nutrition (EN) for the disease process and for patient outcome in severe acute pancreatitis is dramatic. A narrow window of opportunity exists during which there is potential for EN to decrease disease severity and reduce overall complications. Most patients with severe pancreatitis tolerate enteral feeds. Any signs of symptom exacerbation or increasing inflammation in response to EN may be ameliorated by subtle adjustments in the feeding strategy. In this manner, provision of EN represents primary therapy in the management of the patient with acute pancreatitis and is emerging as the gold standard of therapy in nutrition support for this disease process.

  13. Intravenous magnesium for acute asthma?

    PubMed

    2003-10-01

    Each year in the UK, around 1,500 people die from asthma. Standard treatment has been based on bronchodilators (e.g. beta 2-stimulants) and anti-inflammatory drugs (corticosteroids). The recently revised British Guideline on the Management of Asthma suggests also using a single dose of i.v. magnesium sulphate in patients with acute severe asthma, an unlicensed indication. Here we discuss the rationale for giving i.v. magnesium and whether it offers any advantage for patients with acute severe asthma.

  14. Acute liver failure in children.

    PubMed

    Devictor, Denis; Tissieres, Pierre; Afanetti, Mickael; Debray, Dominique

    2011-06-01

    The management of children with acute liver failure mandates a multidisciplinary approach and intense monitoring. In recent years, considerable progress has been made in developing specific and supportive medical measures, but clinical studies have mainly concerned adult patients. There are no specific medical therapies, except for a few metabolic diseases presenting with acute liver failure. Liver transplantation still remains the only definitive therapy in most instances. Recent clinical studies suggest that hepatocyte transplantation may be useful for bridging patients to liver transplantation, for providing metabolic support during liver failure and for replacing liver transplantation in certain metabolic liver diseases.

  15. Acute silicosis with bilateral pneumothorax

    PubMed Central

    Srivastava, G N; Prasad, Rajniti; Meena, Manoj; Hussain, Moosa

    2014-01-01

    We present a case of acute silicosis with bilateral pneumothorax of a 28-year-old man working at a stone crusher factory for 1 year. He presented to the emergency department with cough, respiratory distress and diffuse chest pain. The patient was managed with bilateral intercostal tube drainage under water seal, oxygen inhalation and conservative therapy. On follow-up he showed improvement of resting dyspnoea and was doing well. This case is being reported because of the rare complications of acute silicosis as bilateral pneumothorax. PMID:24862410

  16. Acute tibial tubercle avulsion fractures.

    PubMed

    McKoy, Brodie E; Stanitski, Carl L

    2003-07-01

    Acute tibial tubercle avulsion fractures are uncommon, and these injuries typically occur in mature-appearing adolescent boys involved in jumping sports, particularly basketball. The developmental anatomy of the tibial tuberosity and the changes surrounding normal physiologic epiphysiodesis render this structure susceptible to acute avulsion fractures. Possible associated injuries include patellar and quadriceps avulsions, collateral and cruciate ligament tears, and meniscal damage. The treatment of this injury is based on the amount of displacement and associated injuries. Nondisplaced fractures are treated nonoperatively with cast immobilization. Displaced fractures require open reduction and internal fixation. Even in Type III injuries, the outcome is usually excellent.

  17. Acute interstitial pneumonia and acute exacerbations of idiopathic pulmonary fibrosis.

    PubMed

    Swigris, Jeffrey J; Brown, Kevin K

    2006-12-01

    Acute interstitial pneumonia (AIP) and acute exacerbations of idiopathic pulmonary fibrosis (AEIPF) are similar respiratory disorders characterized by the rapid development of progressive dyspnea and cough. Both frequently lead to respiratory failure and death. Pathologically, each is characterized by the presence of a diffuse alveolar damage (DAD) pattern; in AIP, DAD is the sole pattern, whereas in AEIPF DAD is superimposed upon a background usual interstitial pneumonia. They differ in that patients with AEIPF have preexisting idiopathic pulmonary fibrosis, whereas patients with AIP have no predisposing disorders to account for their disease. Because both presentations overlap with multiple other causes of acute lung injury, a comprehensive evaluation is necessary to rule out disorders such as overwhelming infection or congestive heart failure. Although a confident diagnosis can be achieved without it, a surgical lung biopsy is necessary to provide a definitive diagnosis. Despite minimal evidence, glucocorticoids are frequently begun once microbiological evaluation confirms the absence of infection. Despite therapy, the case fatality rate ranges up to 70% for both, with most patients dying in the first 2 weeks. Survivors of the acute event can recover to their previous baseline; however, most AIP survivors will stabilize with some functional impairment, whereas in those with AEIPF, progressive fibrosis with functional deterioration is the rule.

  18. Glucose Effect in the Acute Porphyrias

    MedlinePlus

    ... You are here Home Diet and Nutrition The glucose effect in acute porphyrias The disorders Acute Intermittent ... are treated initially with the administration of carbohydrate/glucose. This therapy has its basis in the ability ...

  19. General Information about Adult Acute Lymphoblastic Leukemia

    MedlinePlus

    ... Acute Lymphoblastic Leukemia Treatment (PDQ®)–Patient Version General Information About Adult Acute Lymphoblastic Leukemia Go to Health ... the PDQ Adult Treatment Editorial Board . Clinical Trial Information A clinical trial is a study to answer ...

  20. General Information about Adult Acute Myeloid Leukemia

    MedlinePlus

    ... Acute Myeloid Leukemia Treatment (PDQ®)–Patient Version General Information About Adult Acute Myeloid Leukemia Go to Health ... the PDQ Adult Treatment Editorial Board . Clinical Trial Information A clinical trial is a study to answer ...