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1

Comparison of volume-controlled and pressure-controlled ventilation using a laryngeal mask airway during gynecological laparoscopy  

PubMed Central

Background Several publications have reported the successful, safe use of Laryngeal Mask Airway (LMA)-Classic devices in patients undergoing laparoscopic surgery. However, there have been no studies that have examined the application of volume-controlled ventilation (VCV) or pressure-controlled ventilation (PCV) using a LMA during gynecological laparoscopy. The aim of this study is to compare how the VCV and PCV modes and using a LMA affect the pulmonary mechanics, the gas exchange and the cardiovascular responses in patients who are undergoing gynecological laparoscopy. Methods Sixty female patients were randomly allocated to one of two groups, (the VCV or PCV groups). In the VCV group, baseline ventilation of the lung was performed with volume-controlled ventilation and a tidal volume of 10 ml/kg ideal body weight (IBW). In the PCV group, baseline ventilation of the lung using pressure-controlled ventilation was initiated with a peak airway pressure that provided a tidal volume of 10 ml/kg IBW and an upper limit of 35 cmH2O. The end-tidal CO2, the peak airway pressures (Ppeak), the compliance, the airway resistance and the arterial oxygen saturation were recorded at T1: 5 minutes after insertion of the laryngeal airway, and at T2 and T3: 5 and 15 minutes, respectively, after CO2 insufflation. Results The Ppeak at 5 minutes and 15 minutes after CO2 insufflation were significantly increased compared to the baseline values in both groups. Also, at 5 minutes and 15 minutes after CO2 insufflation, there were significant differences of the Ppeak between the two groups. The compliance decreased in both groups after creating the pneumopertoneim (P < 0.05). Conclusions Our results demonstrate that PCV may be an effective method of ventilation during gynecological laparoscopy, and it ensures oxygenation while minimizing the increases of the peak airway pressure after CO2 insufflation.

Jeon, Woo Jae; Bang, Mi Rang; Ko, So-Young

2011-01-01

2

Noninvasive Assisted Pressure-Controlled Ventilation: As Effective as Pressure Support Ventilation in Chronic Obstructive Pulmonary Disease?  

Microsoft Academic Search

Background: Noninvasive ventilation (NIV) is being increasingly used in hypercapnic chronic obstructive pulmonary disease (COPD) patients but the most appropriate ventilation mode is still not known. Objectives: The aim of this study was to investigate if assisted pressure-controlled ventilation (APCV) can be a better alternative to pressure-support ventilation (PSV) for NIV in COPD patients with acute hypercapnic respiratory failure (AHRF).

Cenk Kirakli; Tutku Cerci; Zeynep Zeren Ucar; Onur Fevzi Erer; Hakan Alp Bodur; Semra Bilaceroglu; Serir Aktogu Ozkan

2008-01-01

3

Compariso of two different modes for noninvasive mechanical ventilation in chronic respiratory failure: volume versus pressure controlled device  

Microsoft Academic Search

Comparison of two different modes for noninvasive mechanical ventilation in chronic respiratory failure: volume versus pressure controlled device. B. Schönhofer, M. Sonneborn, P. Haidl, H. Böhrer, D. Köhler. ©ERS Journals Ltd 1997. ABSTRACT: The most commonly used mode of noninvasive mechanical ventila- tion (NMV) is volume-controlled intermittent positive pressure ventilation (IPPV). Pressure support ventilation has recently become increasingly popular, but

B. Schönhofer; M. Sonneborn; P. Haidl; H. Böhrer; D. Köhler

1997-01-01

4

A new design for high stability pressure-controlled ventilation for small animal lung imaging  

NASA Astrophysics Data System (ADS)

We have developed a custom-designed ventilator to deliver a stable pressure to the lungs of small animals for use in imaging experiments. Our ventilator was designed with independent pressure vessels to separately control the Peak Inspiratory Pressure (PIP) and Positive End Expiratory Pressure (PEEP) to minimise pressure fluctuations during the ventilation process. The ventilator was computer controlled through a LabVIEW interface, enabling experimental manipulations to be performed remotely whilst simultaneously imaging the lungs in situ. Mechanical ventilation was successfully performed on newborn rabbit pups to assess the most effective ventilation strategies for aerating the lungs at birth. Highly stable pressures enabled reliable respiratory gated acquisition of projection radiographs and a stable prolonged (15 minute) breath-hold for high-resolution computed tomography of deceased rabbit pups at different lung volumes.

Kitchen, M. J.; Habib, A.; Fouras, A.; Dubsky, S.; Lewis, R. A.; Wallace, M. J.; Hooper, S. B.

2010-02-01

5

Background on PCV  

Center for Biologics Evaluation and Research (CBER)

... Both viruses are common in pigs. Neither PCV1 nor PCV2 are known to infect or cause illness in humans, however PCV2 may cause illness in pigs. ... More results from www.fda.gov/biologicsbloodvaccines/vaccines/approvedproducts

6

Initiation of high-frequency oscillatory ventilation and its effects upon cerebral circulation in pigs: an experimental study  

Microsoft Academic Search

Background. Current practice at high-frequency oscillatory ventilation (HFOV) initiation is a stepwise increase of the constant applied airway pressure to achieve lung recruitment. We hypothesized that HFOV would lead to more adverse cerebral haemodynamics than does pressure controlled ventilation (PCV) in the presence of experimental intracranial hypertension (IH) and acute lung injury (ALI) in pigs with similar mean airway pressure

M. David; K. Markstaller; A. L. Depta; J. Karmrodt; A. Herweling; O. Kempski; M. Geisen; H. W. Gervais

2006-01-01

7

Validation of indirect calorimetry for measurement of energy expenditure in healthy volunteers undergoing pressure controlled non-invasive ventilation support.  

PubMed

The aim of this validation study was to assess the reliability of gas exchange measurement with indirect calorimetry among subjects who undergo non-invasive ventilation (NIV). Oxygen consumption (VO2) and carbon dioxide production (VCO2) were measured in twelve healthy volunteers. Respiratory quotient (RQ) and resting energy expenditure (REE) were then calculated from the measured VO2 and VCO2 values. During the measurement period the subjects were breathing spontaneously and ventilated using NIV. Two different sampling air flow values 40 and 80 l/min were used. The gas leakage from the measurement setup was assessed with a separate capnograph. The mean weight of the subjects was 93 kg. Their mean body mass index was 29 (range 22-40) kg/m2. There was no statistically significant difference in the measured values for VO2, VCO2, RQ and REE during NIV-supported breathing and spontaneous breathing. The change of sampling air flow had no statistically significant effect on any of the above parameters. We found that REE can be accurately measured with an indirect calorimeter also during NIV-supported breathing and the change of sampling air flow does not distort the gas exchange measurement. A higher sampling air flow in indirect calorimetry decreases the possibility for air leakages in the measurement system and increases the reliability of REE measurement. PMID:22207315

Siirala, Waltteri; Noponen, Tommi; Olkkola, Klaus T; Vuori, Arno; Koivisto, Mari; Hurme, Saija; Aantaa, Riku

2011-12-30

8

Effect of a lung recruitment maneuver by high-frequency oscillatory ventilation in experimental acute lung injury on organ blood flow in pigs  

Microsoft Academic Search

Introduction  The objective was to study the effects of a lung recruitment procedure by stepwise increases of mean airway pressure upon\\u000a organ blood flow and hemodynamics during high-frequency oscillatory ventilation (HFOV) versus pressure-controlled ventilation\\u000a (PCV) in experimental lung injury.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Lung damage was induced by repeated lung lavages in seven anesthetized pigs (23–26 kg). In randomized order, HFOV and PCV\\u000a were performed

Matthias David; Hendrik W Gervais; Jens Karmrodt; Arno L Depta; Oliver Kempski; Klaus Markstaller

2006-01-01

9

FISH in polycythemia vera (PCV)  

SciTech Connect

Trisomies 8 and 9 are the most common numerical abnormalities in polycythemia vera (PCV). However, their role in the pathogenesis of the disease is unclear as is their diagnostic or prognostic value. We evaluated the role of fluorescent in-situ hybridization (FISH) as compared to chromosome analysis in the detection of trisomies 8 or 9 in peripheral blood cells of 14 PCV and 5 secondary PCV patients. Using FISH, we found trisomies 8 and 9 in 10 PCV patients above the cutoff levels of 5%. However, no patient with the secondary PCV reached the cutoff level. Out of 10 PCV patients in whom the trisomy was detected by FISH, only in 3 was this trisomy also detected by routine cytogenetics. The incidence of the finding of trisomy 9 correlates with the duration of the disease, suggesting that this is not the primary event in PCV. FISH is a sensitive, convenient and rapid method for diagnosis and follow-up of chromosome aberrations in PCV patients. Application of FISH to larger cohort of patients may provide valuable information regarding their role in initiation and progession of the disease.

Amiel, A.; Gaber, E.; Manor, Y. [Meir General Hospital, Kfar-Saba (Israel)] [and others

1994-09-01

10

Pneumococcal Conjugate Vaccine (PCV13)  

MedlinePLUS

... treat because some strains are resistant to anti-biotics. This makes prevention through vaccination even more important. ... age range are at greatest risk for serious diseases caused by pneumococcal infection.PCV13 vaccine may also ...

11

Measurement of functional residual capacity by helium dilution during partial support ventilation: in vitro accuracy and in vivo precision of the method  

Microsoft Academic Search

Objective  Measurement of functional residual capacity (FRC) during controlled and especially during assisted ventilation remains a challenge\\u000a in the physiological evaluation of ventilated patients. To validate a bag-in-box closed helium dilution technique allowing\\u000a measurements both during pressure-controlled (PCV) and pressure-support ventilation (PSV).\\u000a \\u000a \\u000a \\u000a Design and setting  Experimental study on lung models containing different volumes, and measurements in patients in the intensive care unit of\\u000a a university

Fabiano Di Marco; Lidia Rota Sperti; Barbara Milan; Riccardo Stucchi; Stefano Centanni; Laurent Brochard; Roberto Fumagalli

2007-01-01

12

Tracheostomy and mechanical ventilation weaning in children affected by respiratory virus according to a weaning protocol in a pediatric intensive care unit in Argentina: an observational restrospective trial  

PubMed Central

We describe difficult weaning after prolonged mechanical ventilation in three tracheostomized children affected by respiratory virus infection. Although the spontaneous breathing trials were successful, the patients failed all extubations. Therefore a tracheostomy was performed and the weaning plan was begun. The strategy for weaning was the decrease of ventilation support combining pressure control ventilation (PCV) with increasing periods of continuous positive airway pressure + pressure support ventilation (CPAP + PSV) and then CPAP + PSV with increasing intervals of T-piece. They presented acute respiratory distress syndrome on admission with high requirements of mechanical ventilation (MV). Intervening factors in the capabilities and loads of the respiratory system were considered and optimized. The average MV time was 69 days and weaning time 31 days. We report satisfactory results within the context of a directed weaning protocol.

2011-01-01

13

Clutch pressure control apparatus  

SciTech Connect

A clutch pressure control apparatus is described which comprises: (a) a first function generator for generating a clutch pressure control signal in accordance with a first function such that a clutch pressure control signal P/sub c1/ is definitely determined as a function of an engine rotational speed signal and an accelerator pedal stroke signal; (b) a controller including a second function generator for providing a second clutch pressure control signal P/sub c2/ in accordance with a second function such that when actual engine speed at an initial clutch engagement phase at which a clutch is entering a half-clutch state exceeds a predetermined engine speed limit, which does not provide shock when the clutch is engaged, the second clutch pressure control signal is first set to a temporary low value corresponding to an engine speed not exceeding the predetermined engine speed limit and then in accordance with the second function is allowed to approach a value determined by the first function according to the actual engine speed signal; and (c) a start switch for detecting accelerator pedal stroke and transmission shift position and outputting a start signal to start to operate the controller when transmission is shifted to a running position and the accelerator stroke meets a condition for start.

Koori, Y.; Mitsui, T.

1989-01-24

14

Tank Pressure Control Experiment (TPCE).  

National Technical Information Service (NTIS)

The Tank Pressure Control Experiment (TPCE) is a small self-contained STS payload designed to test a jet mixer for cryogenic fluid pressure control. Viewgraphs are presented that describe project organization, experiment objectives and approach, risk mana...

M. Bentz

1992-01-01

15

Reproduction in porcine circovirus type 2 (PCV2) seropositive gilts inseminated with PCV2b spiked semen  

PubMed Central

Background Since 1999, field evidence of transplacental infection by porcine circovirus type 2 (PCV2) and reproductive failure has been reported in pigs. The objective of this study was to evaluate the clinical and pathological consequences of PCV2 infection in conventional PCV2-seropositive gilts by insemination with PCV2b-spiked semen. Results Six PCV2 seropositive gilts were inseminated with PCV2b-supplemented semen (infected) and three animals with semen and cell culture medium (controls). Only three out of the six infected animals were pregnant by ultrasonography on day 29 after insemination, while two out of the three controls were pregnant. One control gilt aborted on day 23 after insemination but not due to PVC2. Viraemia was demonstrated in four out of six infected and in one control gilt that became infected with PCV2a. Anti-PCV2 antibody titres showed dynamic variations in the infected group throughout the study. Among infected gilts, the animal with the lowest anti-PCV2 titre (1/100) at the beginning of the experiment and another that reached a similar low value during the experiment showed evident seroconversion over time and had also PCV2 positive foetuses. One placenta displayed mild focal necrosis of the chorionic epithelium positively stained by immunohistochemistry for PCV2 antigen. Conclusions PCV2-seropositive gilts can be infected with PCV2 after intrauterine exposure and low maternal antibody titre may increase the probability of a foetal infection.

2012-01-01

16

Effect of Porcine Circovirus Type 2 (PCV2) Vaccination of the Dam on PCV2 Replication In Utero  

Microsoft Academic Search

The aims of this study were to determine if porcine circovirus type 2 (PCV2) vaccination of the dam is effective in preventing fetal PCV2 infection and reproductive failure. Twelve pregnant, PCV2-naïve sows were randomly divided into four groups, with three sows in each group. Group 1 sows served as noninoculated, nonvaccinated negative controls, group 2 sows were vaccinated with a

D. M. Madson; A. R. Patterson; S. Ramamoorthy; N. Pal; X. J. Meng; T. Opriessnig

2009-01-01

17

Experimental reproduction of porcine circovirus type 2 (PCV2)-associated enteritis in pigs infected with PCV2 alone or concurrently with Lawsonia intracellularis or Salmonella typhimurium.  

PubMed

Porcine circovirus (PCV)-associated disease (PCVAD) has emerged to become one of the most economically important pig diseases globally. One of the less commonly recognized clinical manifestations of PCVAD is PCV2 type 2 (PCV2)-associated enteritis in growing pigs; however, experimental confirmation of the ability of PCV2 alone or PCV2 coinfection with other agent(s) to induce enteritis is lacking. In this study, 120 specific-pathogen-free (SPF) pigs were divided randomly into six groups: controls (negative control pigs), PCV2 (inoculated with PCV2), LAW (inoculated with Lawsonia intracellularis), SALM (inoculated with Salmonella typhimurium), PCV2-LAW (concurrently inoculated with PCV2 and Lawsonia intracellularis) and PCV2-SALM (concurrently inoculated with PCV2 and Salmonella typhimurium). One half of the pigs in each group were subject to necropsy examination 14 days postinoculation (dpi) and the remaining pigs were examined at 28 dpi. The average daily weight gain was not different (P>0.05) between groups. Individual pigs inoculated orally with PCV2 regardless of coinfection status (2/10 PCV2, 1/10 PCV2-LAW, 3/10 PCV2-SALM) developed PCVAD with diarrhoea and reduced weight gain or weight loss between 14 and 28 dpi. Those pigs had characteristic microscopic lesions in lymphoid and enteric tissues associated with abundant PCV2 antigen. Enteric lesions were characterized by necrosuppurative and proliferative enteritis with crypt elongation and epithelial hyperplasia in LAW and PCV2-LAW pigs by 14 dpi, ulcerative and necrosuppurative colitis in SALM and PCV2-SALM pigs by 14 dpi, and lymphohistiocytic enteritis with depletion of Peyer's patches in PCV2, PCV2-SALM and PCV2-LAW pigs by 28 dpi. To the authors' knowledge, this is the first report documenting that under experimental conditions, PCV2 can induce enteritis independently from other enteric pathogens and that oral challenge is a potentially important route and perhaps the natural route of PCV2 transmission in growing pigs. PMID:21334002

Opriessnig, T; Madson, D M; Roof, M; Layton, S M; Ramamoorthy, S; Meng, X J; Halbur, P G

2011-02-18

18

Comparative Effects of Vaccination against Porcine Circovirus Type 2 (PCV2) and Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) in a PCV2-PRRSV Challenge Model  

PubMed Central

The objective of the present study was to determine the effects of porcine circovirus type 2 (PCV2) and porcine reproductive and respiratory syndrome virus (PRRSV) vaccinations in an experimental PCV2-PRRSV challenge model, based on virological (viremia), immunological (neutralizing antibodies [NAs], gamma interferon-secreting cells [IFN-?-SCs], and CD4+ CD8+ double-positive cells), and pathological (lesions and antigens in lymph nodes and lungs) evaluations. A total of 72 pigs were randomly divided into 9 groups (8 pigs per group): 5 vaccinated and challenged groups, 3 nonvaccinated and challenged groups, and a negative-control group. Vaccination against PCV2 induced immunological responses (NAs and PCV2-specific IFN-?-SCs) and reduced PCV2 viremia, PCV2-induced lesions, and PCV2 antigens in the dually infected pigs. However, vaccination against PCV2 did not affect the PRRSV immunological responses (NAs and PRRSV-specific IFN-?-SCs), PRRSV viremia, PRRSV-induced lesions, or PRRSV antigens in the dually infected pigs. Vaccination against PRRSV did not induce immunological responses (PRRSV-specific IFN-?-SCs) or reduce PRRSV viremia, PRRSV-induced lesions, or PRRSV antigens in the dually infected pigs. In addition, vaccination against PRRSV increased PCV2 viremia, PCV2-induced lesions, and PCV2 antigens in the dually infected pigs. In summary, vaccination against PCV2 reduced PCV2 viremia, PCV2-induced lesions, and PCV2 antigens in the dually infected pigs. However, vaccination against PRRSV increased PCV2 viremia, PCV2-induced lesions, and PCV2 antigens in the dually infected pigs. Therefore, the PCV2 vaccine decreased the potentiation of PCV2-induced lesions by PRRSV in dually infected pigs. In contrast, the PRRSV vaccine alone did not decrease the potentiation of PCV2-induced lesions by PRRSV in dually infected pigs.

Park, Changhoon; Oh, Yeonsu; Seo, Hwi Won; Han, Kiwon

2013-01-01

19

Epidemiology and transmission of porcine circovirus type 2 (PCV2).  

PubMed

PCV2 has been highly prevalent in the pig population for decades, prior to the emergence of associated clinical disease manifestations that severely affected the pig production worldwide in the late 90s. PCV2 can be further subdivided into several genotypes. From descriptive epidemiologic data, there is evidence of a global shift of the main PCV2 genotypes in different countries from PCV2a to PCV2b, which is generally associated with more severe disease. In addition, from analytic epidemiologic studies, the modified within-herd PCV2 dynamics of infection is strongly related to the increased incidence of clinical disorders associated with PCV2 infection. Because PCV2 is shed for a long time by an extremely large variety of routes, it easily spreads within the population both through horizontal and vertical transmission. Even if airborne transmission cannot be formally excluded, direct contact is certainly the most efficient infectious route due to the simultaneous exposure of susceptible pigs to contaminated respiratory, digestive, and urinary secretions since the probability of transmission is strongly limited by the distance between infectious and susceptible animals. Consequently, farm to farm transmission is restricted to the introduction of infected animals or infected animal products such as semen. More information would be required to assess the risk of other vehicles such as vaccines or feed ingredients since the probability of these products to be contaminated by PCV2 is unknown. However, owing to its transmission characteristics, PCV2 is able to be maintained within pig farms for years without any further need for re-introduction due to the population dynamics of modern pig operations, which continually renew the pool of the susceptible population through replacements and pig movements between compartments. PMID:22178804

Rose, Nicolas; Opriessnig, Tanja; Grasland, Béatrice; Jestin, André

2011-12-09

20

A PCV2 vaccine based on genotype 2b is more effective than a 2a-based vaccine to protect against PCV2b or combined PCV2a/2b viremia in pigs with concurrent PCV2, PRRSV and PPV infection.  

PubMed

The predominant genotype of porcine circovirus (PCV) in the pig population today is PCV2b yet PCV2a-based commercial vaccines are considered effective in protecting against porcine circovirus associated disease. The objective of this study was to compare the ability of PCV2a- and PCV2b-based vaccines to control PCV2b viremia in a challenge model that mimics the U.S. field situation. Sixty-three pigs were randomly assigned to one of eight groups. Sixteen pigs were vaccinated with an experimental live-attenuated chimeric PCV1-2a vaccine based on genotype 2a and another 16 pigs with a chimeric PCV1-2b vaccine based on genotype 2b. Challenge was done 28 days post vaccination (dpv) using PCV2b (or a combination of PCV2a and PCV2b), porcine reproductive and respiratory syndrome virus (PRRSV), and porcine parvovirus (PPV) to mimic what commonly occurs in the field. The experiment was terminated 21 days post challenge (dpc) or 49dpv. Pigs vaccinated with the chimeric PCV1-2b vaccine had significantly higher levels of PCV1-2b viremia and shedding of the PCV1-2b vaccine virus in feces and nasal secretions but also a more robust humoral immune response as evidenced by significantly higher ELISA S/P ratios compared to the PCV1-2a vaccination. Regardless of challenge, the PCV1-2b vaccination significantly reduced the prevalence and amount of PCV2 viremia compared to the PCV1-2a vaccination. Interestingly, in the non-vaccinated pigs concurrent PCV2a infection resulted in clinical disease and increased macroscopic lung lesions compared to pigs challenged with PCV2b alone, further supporting the idea that concurrent PCV2a/PCV2b infection is necessary for optimal PCV2 replication. PMID:23174198

Opriessnig, Tanja; O'Neill, Kevin; Gerber, Priscilla F; de Castro, Alessandra M M G; Gimenéz-Lirola, Luis G; Beach, Nathan M; Zhou, Lei; Meng, Xiang-Jin; Wang, Chong; Halbur, Patrick G

2012-11-19

21

Detection of DNA from PCV1 in Rotarix  

Center for Biologics Evaluation and Research (CBER)

... of components of PCV1 in Rotarix was discovered when an independent US academic research team applied a new technology for detecting viral ... More results from www.fda.gov/biologicsbloodvaccines/vaccines/approvedproducts

22

Phase III Randomized Study of Postradiotherapy Chemotherapy with Combination -Difluoromethylornithine-PCV versus PCV for Anaplastic Gliomas 1  

Microsoft Academic Search

Purpose: In the current study, we sought to determine whether the addition of DFMO (-difluoromethyl ornithine; eflornithine), an inhibitor of ornithine decarboxylase, to a nitrosourea-based therapy procarbazine, 1-(2-chloroethyl)- 3-cyclohexyl-1-nitrosourea, vincristine (PCV) would be more effective as a postirradiation adjuvant therapy for anaplastic gliomas (AG) than PCV alone. Patients and Methods: After conventional radiation therapy, 249 AG patients were randomized to

Victor A. Levin; Kenneth R. Hess; Ali Choucair; Patrick J. Flynn; Kurt A. Jaeckle; Athanassios P. Kyritsis; W. K. Alfred Yung; Michael D. Prados; Janet M. Bruner; Sandra Ictech; Mary Jo Gleason; Hyung-Woo Kim

2003-01-01

23

Mechanical ventilation of the premature neonate.  

PubMed

Although the trend in the neonatal intensive care unit is to use noninvasive ventilation whenever possible, invasive ventilation is still often necessary for supporting pre-term neonates with lung disease. Many different ventilation modes and ventilation strategies are available to assist with the optimization of mechanical ventilation and prevention of ventilator-induced lung injury. Patient-triggered ventilation is favored over machine-triggered forms of invasive ventilation for improving gas exchange and patient-ventilator interaction. However, no studies have shown that patient-triggered ventilation improves mortality or morbidity in premature neonates. A promising new form of patient-triggered ventilation, neurally adjusted ventilatory assist (NAVA), was recently FDA approved for invasive and noninvasive ventilation. Clinical trials are underway to evaluate outcomes in neonates who receive NAVA. New evidence suggests that volume-targeted ventilation modes (ie, volume control or pressure control with adaptive targeting) may provide better lung protection than traditional pressure control modes. Several volume-targeted modes that provide accurate tidal volume delivery in the face of a large endotracheal tube leak were recently introduced to the clinical setting. There is ongoing debate about whether neonates should be managed invasively with high-frequency ventilation or conventional ventilation at birth. The majority of clinical trials performed to date have compared high-frequency ventilation to pressure control modes. Future trials with premature neonates should compare high-frequency ventilation to conventional ventilation with volume-targeted modes. Over the last decade many new promising approaches to lung-protective ventilation have evolved. The key to protecting the neonatal lung during mechanical ventilation is optimizing lung volume and limiting excessive lung expansion, by applying appropriate PEEP and using shorter inspiratory time, smaller tidal volume (4-6 mL/kg), and permissive hypercapnia. This paper reviews new and established neonatal ventilation modes and strategies and evaluates their impact on neonatal outcomes. PMID:21944682

Brown, Melissa K; DiBlasi, Robert M

2011-09-01

24

A genetically engineered chimeric vaccine against porcine circovirus type 2 (PCV2) is genetically stable in vitro and in vivo  

Microsoft Academic Search

A vaccine against porcine circovirus type 2 (PCV2), designated PCV1-2 chimera, was recently developed by replacing the capsid gene of the non-pathogenic PCV1 with that of PCV2. The PCV1-2 chimera virus is attenuated in pigs but induces protective immunity against PCV2. In this study, the genetic stability of the PCV1-2 chimera was evaluated for its potential use as a live

J. Gillespie; N. M. Juhan; J. DiCristina; K. F. Key; S. Ramamoorthy; X. J. Meng

2008-01-01

25

Serotype dynamics of invasive pneumococcal disease post-PCV7 and pre-PCV13 introduction in North East England.  

PubMed

SUMMARYThe 7-valent pneumococcal conjugate vaccine (PCV7) has been included in the routine childhood immunization programme in the UK since September 2006. A population-based study of serotypes causing invasive pneumococcal disease (IPD) post-PCV7 in North East England was conducted using data from a regional enhanced IPD surveillance system. Overall, there was a 20% reduction [95% confidence interval (CI) 5-32] from 12·1 cases/100 000 population in 2006/2007 to 9·7 in 2009/2010. There was a fall in IPD caused by PCV7 serotypes in all age groups, with reductions of 90% (95% CI 61-99) in children aged <5 years, 50% (95% CI 4-75) in persons aged 5-64 years and 66% (95% CI 40-82) in adults aged ?65 years. There was a non-significant increase in IPD caused by non-PCV7 serotypes in children aged <5 years of 88% (95% CI -10 to 312) and adults aged ?65 years of 12% (95% CI -19 to 50), which was largely caused by serotypes 7F, 19A and 22F. Replacement disease appears to have reduced the benefits of PCV7 in North East England. PMID:22564258

Chapman, K E; Wilson, D; Gorton, R

2012-05-01

26

Reduction of porcine circovirus type 2 (PCV2) viremia by a reformulated inactivated chimeric PCV1-2 vaccine-induced humoral and cellular immunity after experimental PCV2 challenge  

PubMed Central

Background The objective of the present study was to elucidate the humoral and cellular immune response mechanisms by which a reformulated inactivated chimeric PCV1-2 vaccine reduces the PCV2 viremia. Forty PCV2 seronegative 3-week-old pigs were randomly divided into the following four groups: vaccinated challenged (T01), vaccinated non-challenged (T02), non-vaccinated challenged (T03), and non-vaccinated non-challenged (T04) animals. The pigs in groups T01 and T02 were immunized with a reformulated inactivated chimeric PCV1-2 vaccine (Fostera™ PCV; Pfizer Animal Health) administered as a 2.0 ml dose at 21 days of age. At 35 days of age (0 days post-challenge), the pigs in groups T01 and T03 were inoculated intranasally with 2 ml each of PCV2b. Results A reduction of PCV2 viremia coincided with the appearance of both PCV2-specific neutralizing antibodies (NA) and interferon-?-secreting cells (IFN-?-SCs) in the vaccinated animals. However, the presence of anti-PCV2 IgG antibodies did not correlate with the reduction of PCV2 viremia. Lymphocyte subset analysis indicated that the numbers of CD3+ and CD4+ cells increased in vaccinated animals but the numbers of CD4+ cells decreased transiently in non-vaccinated animals. The observation of a delayed type hypersensitivity response in only the vaccinated animals also supports a CD4+ cell-associated protective cellular immune response induced by the reformulated inactivated chimeric PCV1-2 vaccine. Conclusions The induction of PCV2-specific NA and IFN-?-SCs, and CD4+ cells by the reformulated inactivated chimeric PCV1-2 vaccine is the important protective immune response leading to reduction of the PCV2 viremia and control of the PCV2 infection. To our knowledge this is the first demonstration of protective humoral and cellular immunity induced by the reformulated inactivated chimeric PCV1-2 vaccine and its effect on reduction of PCV2 viremia by vaccination.

2012-01-01

27

Controller modeling and evaluation for PCV electro-mechanical actuator  

Microsoft Academic Search

Hydraulic actuators are currently used to operate the propellant control valves (PCV) for the space shuttle main engine (SSME) and other rocket engines. These actuators are characterized by large power to weight ratios, large force capabilities, and rapid accelerations, which favor their use in control valve applications. However, hydraulic systems are also characterized by susceptibility to contamination, which leads to

Joey K. Parker

1993-01-01

28

Characterisation of PCV2 isolates from Spain, Germany and France  

Microsoft Academic Search

The new isolated circovirus variant PCV-2 is discussed to be the etiological agent of a new emerging swine disease with a variable morbidity and high lethality, postweaning multisystemic wasting syndrome (PMWS). PMWS has been diagnosed in North America and West Europe. Clinical signs include dyspnea, loss of weight, lymph node enlargement and lymphocyte depletion in lymphoid tissues. This report describes

Annette Mankertz; Mariano Domingo; Josep M Folch; Pierre LeCann; André Jestin; Joaquim Segalés; Barbara Chmielewicz; Juan Plana-Durán; Dirk Soike

2000-01-01

29

Protective effect of the maternally derived porcine circovirus type 2 (PCV2)-specific cellular immune response in piglets by dam vaccination against PCV2 challenge.  

PubMed

The objective of the present study was to evaluate (i) the passive transfer of maternally derived functional porcine circovirus type 2 (PCV2)-specific lymphocytes of seronegative sows immunized with the PCV2 vaccine to newborn piglets and (ii) the functional role of the maternally derived PCV2-specific cellular immune response in protecting newborn piglets from challenge with PCV2. After ingesting colostrums, piglets from vaccinated sows (PT01 and PT02) have significantly higher numbers of PCV2-specific gamma interferon-secreting cells, an increased PCV2-specific delayed type hypersensitivity response, and a stronger proliferative response of peripheral blood mononuclear cells compared with piglets from non-vaccinated seronegative sows (PT03 and PT04). In the PCV2 challenge study, the number of serum genomic PCV2 copies was significantly less in piglets from vaccinated sows (PT02) compared with piglets from non-vaccinated sows (PT04) at 7-28 days post-inoculation (P<0.05 and P<0.001). The histopathological lesions and immunohistochemical scores were significantly lower in piglets of vaccinated sows compared with those of non-vaccinated sows. To our knowledge, this is the first report of transferring a maternally derived PCV2-specific cellular immune response from vaccinated dams to their offspring. Maternally derived adaptive cellular immune responses play a critical role in protecting newborn piglets challenged with PCV2 at 3 weeks of age. PMID:22495234

Oh, Yeonsu; Seo, Hwi Won; Han, Kiwon; Park, Changhoon; Chae, Chanhee

2012-04-11

30

Detection of Genetic characterization of Porcine circovirus 2 (PCV2) in Brazilian wildlife boars  

PubMed Central

A semi-intensive wildlife boars farm presented a clinical history of high mortality in 70 – 90 days-old pigs (> 50 %). Two 90 days-old animals with weight loss and wasting were necropsied and the samples tested for PCV2 by polymerase chain reaction (PCR). The genetic material of PCV2 was sequenced and classified into the PCV2a genotype together with PCV2 sequences obtained from samples of Poland, Brazil, Slovenia and Greece wild boars.

Castro, A.M.M.G.; Castro, F.G.; Budino, F.E.L.; Baldin, C.M.; Silva, S.O.S.; Brandao, P.E.; Richtzenhain, L.J.

2012-01-01

31

Functional exchangeability of the nuclear localization signal (NLS) of capsid protein between PCV1 and PCV2 in vitro: Implications for the role of NLS in viral replication  

Microsoft Academic Search

Background  Porcine circovirus type 2 (PCV2) is believed to be the primary causative agent of postweaning multisystemic wasting syndrome\\u000a (PMWS). It is supposed that capsid protein of PCV may contribute to replication control via interaction between Cap and Rep\\u000a in the nucleoplasm. In this study, we described the construction and in vitro characterization of NLS-exchanged PCV DNA clones\\u000a based on a

Jiangbing Shuai; Linglin Fu; Xiaofeng Zhang; Binglin Zhu; XiaoLiang Li; Yongqiang He; Weihuan Fang

2011-01-01

32

Control Applications in Artificial Ventilation (Invited Paper)  

Microsoft Academic Search

The history of artificial ventilation is closely related to the origin of anesthesia. After the introduction of ether for use as a anesthetic drug in Boston, USA, in 1846, the need for artificial ventilation soon became evident. Soon after, the first medical devices allowing proper dosing of the agents, guaranteeing pressure control of the carrier gases and offering bags for

Marian Walter; Steffen Leonhardt

33

Survival following adjuvant PCV or temozolomide for anaplastic astrocytoma  

PubMed Central

We compared survival in patients with anaplastic astrocytoma (AA) treated with adjuvant procarbazine, lomustine, and vincristine (PCV) with survival in patients treated with temozolomide. A retrospective analysis was made of patients with newly diagnosed AA treated with adjuvant postradiotherapy chemotherapy. Outcome analysis included progression-free survival and overall survival. The following prognostic factors were taken into account: patient age, extent of resection, performance status, presence of contrast enhancement in pre-surgical imaging, and type of adjuvant treatment. Among 109 AA patients, 49 were treated with PCV and 60 with temozolomide. The treatment groups were well matched for pretreatment characteristics, except for the presence of contrast enhancement. Age, extent of surgery, performance status, and presence of contrast enhancement were statistically significant prognostic factors according to the Cox model analysis of survival. Type of adjuvant chemotherapy was not a significant factor, either for progression-free survival or for overall survival. Hematological toxicity, nonhematological toxicity grades 3–4, and premature discontinuation due to toxicity were observed in 9%, 3% to 5%, and 37%, respectively, of cases in the PCV group versus 4% to 5%, 0, and 0, respectively, in the temozolomide group. Although the present study was not randomized, it was well designed, and it reports on two homogeneous and consecutive series of patients, for whom histology was verified to obtain survival data only for patients with AA following the recent WHO 2000 classification. Even if no survival advantage has been demonstrated for temozolomide versus PCV, we conclude that temozolomide should be preferred because of its greater tolerability.

Brandes, Alba A.; Nicolardi, Linda; Tosoni, Alicia; Gardiman, Marina; Iuzzolino, Paolo; Ghimenton, Claudio; Reni, Michele; Rotilio, Antonino; Sotti, Guido; Ermani, Mario

2006-01-01

34

Mycoplasma hyopneumoniae bacterins and porcine circovirus type 2 (PCV2) infection: Induction of postweaning multisystemic wasting syndrome (PMWS) in the gnotobiotic swine model of PCV2-associated disease  

PubMed Central

Groups (5 to 15 per group) of gnotobiotic swine were infected oronasally with porcine circovirus type 2 (PCV2) at 3 days of age and then given 1 of 6 different commercial Mycoplasma hyopneumoniae (M. hyopneumoniae) bacterins as either a single dose (7 d of age, 1 application products) or 2 doses (7 and 21 d of age, 2 application product). Control groups received PCV2 alone (n = 9) or were infected with PCV2 and immunized twice with keyhole limpet hemocyanin (KLH) emulsified in incomplete Freund’s adjuvant (ICFA) (n = 7). Five of 7 (71%) PCV2-infected piglets immunized with KLH/ICFA developed mild or overt PMWS, whereas none of 9 piglets infected with PCV2 alone developed PMWS. Five of 12 (42%) piglets vaccinated with a commercial bacterin containing mineral oil adjuvant developed PMWS following vaccination. None of the PCV2-infected piglets in the other bacterin-vaccinated groups developed PMWS in this model of PCV2-associated disease. This difference in prevalence of PMWS in piglets given the mineral oil-adjuvanted M. hyopneumoniae bacterin and the other M. hyopneumoniae bacterin vaccination groups was statistically significant (P < 0.05).

Krakowka, Steven; Ellis, John; McNeilly, Francis; Waldner, Cheryl; Rings, D. Michael; Allan, Gordon

2007-01-01

35

Fetal infections and antibody profiles in pigs naturally infected with porcine circovirus type 2 (PCV2).  

PubMed

The aim of this study was to describe early infections with porcine circovirus type 2 (PCV2) in naturally infected piglets and the piglets' serologic profiles. A total of 20 sows (15 PCV2-vaccinated and 5 unvaccinated) and 100 newborn piglets were studied. Colostrum and serum of the sows and serum of the presuckling piglets were obtained on the day of parturition. Milk samples were collected on day 20 postpartum. Blood samples were taken and the piglets weighed on days 1, 20, 42, 63, and 84 postpartum. Colostrum and milk were evaluated for infectious PCV2 and for PCV2 total antibody (TA), neutralizing antibody (NA), and IgA. Serum samples were evaluated for PCV2 TA, NA, IgA, IgM, and DNA. The sows had high levels of TA and NA in serum and colostrum; however, 11 and 5, respectively, of the 20 colostrum and milk samples contained infectious PCV2. In the serum, PCV2 DNA and IgM were detected in 17 and 5, respectively, of the 20 sows. Nine piglets were born with PCV2 antibodies, which indicates in utero transmission of PCV2 after the period of immunocompetence (> 70 d of gestation). On day 1 postpartum, PCV2 DNA was detected in 29 of the 100 serum samples from the piglets. There was no difference between the weights of viremic and nonviremic piglets throughout the study. In conclusion, even on farms with sows that have high PCV2 antibody titers, vertical transmission of PCV2 may occur, resulting in piglet infection. PMID:22754093

Gerber, Priscilla F; Garrocho, Flávia M; Lana, Angela M Q; Lobato, Zélia I P

2012-01-01

36

Fetal infections and antibody profiles in pigs naturally infected with porcine circovirus type 2 (PCV2)  

PubMed Central

The aim of this study was to describe early infections with porcine circovirus type 2 (PCV2) in naturally infected piglets and the piglets’ serologic profiles. A total of 20 sows (15 PCV2-vaccinated and 5 unvaccinated) and 100 newborn piglets were studied. Colostrum and serum of the sows and serum of the presuckling piglets were obtained on the day of parturition. Milk samples were collected on day 20 postpartum. Blood samples were taken and the piglets weighed on days 1, 20, 42, 63, and 84 postpartum. Colostrum and milk were evaluated for infectious PCV2 and for PCV2 total antibody (TA), neutralizing antibody (NA), and IgA. Serum samples were evaluated for PCV2 TA, NA, IgA, IgM, and DNA. The sows had high levels of TA and NA in serum and colostrum; however, 11 and 5, respectively, of the 20 colostrum and milk samples contained infectious PCV2. In the serum, PCV2 DNA and IgM were detected in 17 and 5, respectively, of the 20 sows. Nine piglets were born with PCV2 antibodies, which indicates in utero transmission of PCV2 after the period of immunocompetence (> 70 d of gestation). On day 1 postpartum, PCV2 DNA was detected in 29 of the 100 serum samples from the piglets. There was no difference between the weights of viremic and nonviremic piglets throughout the study. In conclusion, even on farms with sows that have high PCV2 antibody titers, vertical transmission of PCV2 may occur, resulting in piglet infection.

Gerber, Priscilla F.; Garrocho, Flavia M.; Lana, Angela M.Q.; Lobato, Zelia I.P.

2012-01-01

37

Development of an adaptive neuro-fuzzy method for supply air pressure control in HVAC system  

Microsoft Academic Search

An adaptive neuro-fuzzy (ANF) method is developed for the supply air pressure control loop of a heating, ventilation and air-conditioning (HVAC) system. Although a well-tuned PID controller performs well around normal working points, its tolerance to process parameter variations is severely affected due to the nature of PID controllers. The ANF controller developed overcomes this weakness. The controller design involves

Wu Jian; Cai Wenjian

2000-01-01

38

ORF1 but not ORF2 dependent differences are important for in vitro replication of PCV2 in porcine alveolar macrophages singularly or coinfected with PRRSV.  

PubMed

The objective of this study was to investigate cytokine expression and in vitro replication of porcine circovirus type 2 (PCV2) and porcine reproductive and respiratory syndrome virus (PRRSV) in pulmonary alveolar macrophages (PAMs) emphasizing PCV2 open-reading frame (ORF) origin (PCV2a or PCV2b) and PRRSV strain. Chimeric PCV2 viruses composed of different combinations of ORF1 and ORF2 of PCV2a or PCV2b (chimera PCV2a-2b and chimera PCV2b-2a) were constructed and five different PRRSV isolates were utilized: Type 1 (SD 01-08) or type 2 (NC16845b, VR-2332, MN-184, JA-142). PAMs were infected singularly or with combinations of PCV2b, PCV2a, chimera PCV2a-2b, and chimera PCV2b-2a, and one of the five PRRSV isolates. Real-time PCR was used to test PAMs (PCV2 mRNA) and supernatants (PRRSV RNA, PCV2 DNA, PCV2 mRNA) harvested at 24, 48, 72 and 96h post inoculation (hpi). Levels of IFN-?, TNF-? and IL-10 were determined by quantitative ELISAs. PCV2 replication in PAMs was limited to groups inoculated with PCV2 strains containing ORF1 of PCV2a (PCV2a, chimera PCV2a-2b). Furthermore, in supernatants, PCV2 mRNA was only detected in groups coinfected with PRRSV regardless of strain at 48hpi supporting an enhancing effect of PRRSV on PCV2 infection. Changes in cytokine levels were minimal and associated with PRRSV strain for TNF-?. In summary, in vitro differences in PCV2 replication in PAMs inoculated with different PCV2-PRRSV combinations were independent of PCV2 ORF2 origin with minimal effects of concurrent PRRSV infection perhaps indicating that PCV2-specific changes in ORF1 may be more important than those in ORF2. PMID:22406345

Sinha, Avanti; Lin, Kathy; Hemann, Michelle; Shen, Huigang; Beach, Nathan M; Ledesma, Carmen; Meng, Xiang-Jin; Wang, Chong; Halbur, Patrick G; Opriessnig, Tanja

2012-02-17

39

The effect of head rotation on efficiency of ventilation and cuff pressure using the PLMA in pediatric patients  

PubMed Central

Background This study examined whether changing the head position from neutral to side can affect expiratory tidal volume (TV) and cuff pressure when the appropriate sizes of a Proseal™ Laryngeal Mask Airway (PLMA)-depending on the body weight -are used in pediatric patients during pressure controlled ventilation (PCV). Methods Seventy-seven children (5-30 kg) were divided into three groups according to their body weight, PLMA#1.5 (group I, n = 24), #2 (group II, n = 26), and #2.5 (group III, n = 27). After anesthesia induction, a PLMA was placed with a cuff-pressure of 60 cmH2O. The TV and existence of leakage at the peak inspiratory pressure (PIP) of 20 cmH2O, and the appropriate PIP for TV 10 ml/kg were examined. Upon head rotation to the left side, the TV, PIP, cuff pressure changes, and the appropriate PIP to achieve a TV 10 ml/kg were evaluated. Results Head rotation of 45 degrees to the left side during PCV caused a significant increase in cuff pressure and a decrease in TV, and there was no definite leakage. Changes in PIP and TV were similar in the three groups. The cuff pressure increased but there was no significant difference between the three groups. Conclusions Although cuff pressure and TV of the PLMA were changed significantly after turning the head from the neutral position to the side, a re-adjustment of the cuff pressure and PIP to maintain a TV of 10 ml/kg can make the placed PLMA useful and successful in pediatric patients under general anesthesia.

Park, Hahck Soo; Kim, Youn Jin

2011-01-01

40

pPCV, a versatile vector for cloning PCR products.  

PubMed

The efficiency of PCR product cloning depends on the nature of the DNA polymerase employed because amplicons may have blunt-ends or 3' adenosines overhangs. Therefore, for amplicon cloning, available commercial vectors are either blunt-ended or have a single 3' overhanging thymidine. The aim of this work was to offer in a single vector the ability to clone both types of PCR products. For that purpose, a minimal polylinker was designed to include restriction sites for EcoRV and XcmI which enable direct cloning of amplicons bearing blunt-ends or A-overhangs, respectively, still offering blue/white selection. When tested, the resulting vector, pPCV, presented high efficiency cloning of both types of amplicons. PMID:24058893

Janner, Christiane R; Brito, Ana Lívia P; Moraes, Lidia Maria P; Reis, Viviane Cb; Torres, Fernando Ag

2013-09-05

41

Diagnostic Relevance of Pressure-Controlled Discography  

PubMed Central

Discogenic pain is a leading cause of chronic low back pain. The authors investigated the efficacy of pressure-controlled discography to determine its role in clinical decision-making for the management of patients with discogenic pain. Pressure-controlled discography was performed in 21 patients (51 discs) with pain-provocation, followed by post-discography computerized tomography scans. Pain response was classified as positive response and negative response, and measured with visual analog scale scores. Discographic findings were graded by the modified Dallas discogram scale. Elastance, pain provocation on intradiscal pressure, pressure and volume of initial pain response, and pain response intensity were statistically analyzed. Elastance showed significant differences between Grade 0 and Grade 4 & 5. Decreased elastance with positive pain response group was a good indicator to imply that disc degeneration presumably is a pain generator. Results of pain response were well correlated with intradiscal pressure but not with the amount of injected volume. Among 31 discs of Grade 4 and 5, 74% showed negative pain response and 26% showed positive response. It was concluded that pressure-controlled discography was useful to diagnose discogenic pain and excellent guide in decision-making for spinal operations.

Shin, Dong-Ah; Jung, Jae-Hyun; Shin, Dong-Gyu; Lee, Jung-Ok

2006-01-01

42

A Porcine Circovirus Type 2 (PCV2) Mutant with 234 Amino Acids in Capsid Protein Showed More Virulence In Vivo, Compared with Classical PCV2a/b Strain  

PubMed Central

Background Porcine circovirus type 2 (PCV2) is considered to be the primary causative agent of postweaning multisystemic wasting syndrome (PMWS), which has become a serious economic problem for the swine industry worldwide. The major genotypes, PCV2a and PCV2b, are highly prevalent in the pig population and are present worldwide. However, another newly emerging PCV2b genotype mutant, which has a mutation in its ORF2-encoded capsid protein, has been sporadically present in China, as well as in other countries. It is therefore important to determine the relative virulence of the newly emerging PCV2b genotype mutant, compared with the existing PCV2a and PCV2b genotypes, and to investigate whether the newly emerging mutant virus induces more severe illness. Methodology/Principal Findings Twenty healthy, 30-day-old, commercial piglets served as controls or were challenged with PCV2a, PCV2b and the newly emerging mutant virus. A series of indexes representing different parameters were adopted to evaluate virulence, including clinical signs, serological detection, viral load and distribution, changes in immune cell subsets in the peripheral blood, and evaluation of pathological lesions. The newly emerging PCV2 mutant demonstrated more severe signs compatible with PMWS, characterized by wasting, coughing, dyspnea, diarrhea, rough hair-coat and depression. Moreover, the pathological lesions and viremia, as well as the viral loads in lymph nodes, tonsils and spleen, were significantly more severe (P<0.05) for piglets challenged with the newly emerging mutant compared with those in the groups challenged with PCV2a and PCV2b. In addition, a significantly lower average daily weight gain (P<0.05) was recorded in the group challenged with the newly emerging PCV2 mutant than in the groups challenged with the prevailing PCV2a and PCV2b. Conclusions This is believed to be the first report to confirm the enhanced virulence of the newly emerging PCV2 mutant in vivo.

Guo, Longjun; Fu, Yujie; Wang, Yiping; Lu, Yuehua; Wei, Yanwu; Tang, Qinghai; Fan, Peihu; Liu, Jianbo; Zhang, Long; Zhang, Feiyan; Huang, Liping; Liu, Dan; Li, Shengbin; Wu, Hongli; Liu, Changming

2012-01-01

43

The AVL-mode: A safe closed loop algorithm for ventilation during total intravenous anesthesia  

Microsoft Academic Search

The Adaptive Lung Ventilation Controller (ALV-Controller) represents a new approach to closed loop control of ventilation.\\u000a It is based on a pressure controlled ventilation mode. Adaptive lung ventilation signifies automatic breath by breath adaptation\\u000a of breathing patterns to the lung mechanics of an individual patient. The specific goals are to minimize work of breathing,\\u000a to maintain a preset alveolar ventilation

N. Weiler; W. Heinrichs; W. Keßler

1994-01-01

44

Laser beam duct pressure controller system  

NASA Astrophysics Data System (ADS)

Disclosed is a laser beam duct pressure controller system for maintaining a spatially uniform pressure in a flowing gas volume which is subjected to temporal pressure variations. This desired result is accomplished with cooperating structural components (and gases therein), which eliminate the axial flow of a conditioning gas within the laser beam duct by matching the time rate of change of the pressure of the flowing conditioning gas to the time rate of change of the pressure in the cavity of an operably associated laser beam turret.

Laderman, A. J.; Bergthold, F. M., Jr.

1985-09-01

45

[Field trial on the simultaneous vaccination against porcine circovirus type 2 (PCV2) and Mycoplasma hyopneumoniae].  

PubMed

Objective: The objective of the present study was to investigate whether a combined or concurrent application of two vaccines against Mycoplasma hyopneumoniae (M. hyo.) and porcine circovirus type 2 (PCV2) in suckling piglets can be as effective as the single use of both products. Material and methods: A total of 598 piglets were allocated to five groups. In the 1st and 3rd weeks of life the placebo Porcilis® Diluvac forte and the two vaccines Porcilis® M HYO ("M HYO") and Porcilis® PCV ("PCV") were administered according to the following scheme: group A: placebo/PCV; group B: M HYO/M HYO; group C: placebo/placebo; group D: M HYO/M HYO + PCV (combined single dose); group E: placebo/M HYO + PCV (different injection sites). Lung lesions due to M. hyo. infection were recorded at slaughter, and average daily weight gain, morbidity, mortality, serum PCV2 load and specific humoral immune responses were compared between the groups. Local and systemic side effects were recorded. Results: Sporadic impairment of the herd health status due to piglet diarrhoea (n = 111) from the 1st to 3rd weeks of life were not associated with M. hyo. or PCV2. A tendency towards a higher average daily weight gain was found in vaccinated pigs compared to the control group. Slight differences between groups in terms of lung lesions, morbidity and mortality were not significant. M. hyo. and PCV2 antibody-titers were significantly higher in vaccinated than in non-vaccinated pigs. One pig from both group A (PCV2) and group C (placebo) displayed local reactions at the vaccination site. Conclusion and clinical relevance: A positive effect on animal health can be achieved by vaccination against M. hyo. and PCV2 in herds with suboptimal health status. A simultaneous vaccination either by a combined or concurrent application has no negative effect on health status. Simultaneous vaccination yielded the same positive effect on average daily weight gain as single vaccinations. Therefore, a simultaneous vaccination against M. hyo. and PCV2, which reduces workload and is beneficial for animal welfare, can be recommended. PMID:24126996

Herbich, E; Heissenberger, B; Ladinig, A; Griessler, A; Ritzmann, M; Weissenbacher-Lang, C; Hennig-Pauka, I

2013-10-15

46

Pressure support versus assisted controlled noninvasive ventilation in neuromuscular disease  

Microsoft Academic Search

Introduction: Noninvasive ventilation (NIV) is being increasingly used in patients with chronic neuromuscular disorders, but the optimal\\u000a ventilation mode remains unknown. We compared physiological short-term effects of assist\\/controlled ventilation (ACV) and\\u000a two pressure-limited modes (pressure-support ventilation [PSV] and assist pressure-controlled ventilation [ACPV]) in patients\\u000a with neuromuscular disease who needed NIV.\\u000a \\u000a \\u000a Methods: Tidal volume was 10 to 12 mL\\/kg. The ACPV

Karim Chadda; Bernard Clair; David Orlikowski; Gilles Macadoux; Jean Claude Raphael; Frédéric Lofaso

2004-01-01

47

Automated gate valve operation for pressure control  

NASA Astrophysics Data System (ADS)

An automated pressure control system is described. The components consist of a reversible, geared, ac motor, a gate valve, a Granville-Phillips Stabil-ion pressure gauge with set-points and an electronics switching unit. The reversible motor is attached to the adjustment shaft of the gate valve and the system is operated in conjunction with a diffusion pump. The orifice of the gate valve is varied so that the chamber pressure is maintained between two selected set-points fixed on the control unit of the Stabil-ion pressure gauge. The system is used to control the operating pressure in a chemical vapor deposition process. It has been found to work satisfactorily for both gas and liquid phase precursor materials. The simplicity of the system together with its low cost allows for its use in a variety of low-pressure processes.

Barshilia, Harish C.; Kalmar, Balazs; Windsor, Norman R.; Kershmann, Gordon; O'Brien, James J.

1998-02-01

48

Ventilation Model  

SciTech Connect

The purpose of this analysis and model report (AMR) for the Ventilation Model is to analyze the effects of pre-closure continuous ventilation in the Engineered Barrier System (EBS) emplacement drifts and provide heat removal data to support EBS design. It will also provide input data (initial conditions, and time varying boundary conditions) for the EBS post-closure performance assessment and the EBS Water Distribution and Removal Process Model. The objective of the analysis is to develop, describe, and apply calculation methods and models that can be used to predict thermal conditions within emplacement drifts under forced ventilation during the pre-closure period. The scope of this analysis includes: (1) Provide a general description of effects and heat transfer process of emplacement drift ventilation. (2) Develop a modeling approach to simulate the impacts of pre-closure ventilation on the thermal conditions in emplacement drifts. (3) Identify and document inputs to be used for modeling emplacement ventilation. (4) Perform calculations of temperatures and heat removal in the emplacement drift. (5) Address general considerations of the effect of water/moisture removal by ventilation on the repository thermal conditions. The numerical modeling in this document will be limited to heat-only modeling and calculations. Only a preliminary assessment of the heat/moisture ventilation effects and modeling method will be performed in this revision. Modeling of moisture effects on heat removal and emplacement drift temperature may be performed in the future.

H. Yang

1999-11-04

49

An adaptive lung ventilation controller.  

PubMed

Closed loop control of ventilation is traditionally based on end-tidal or mean expired CO2. The controlled variables are the respiratory rate RR and the tidal volume VT. Neither patient size or lung mechanics were considered in previous approaches. Also the modes were not suitable for spontaneously breathing subjects. This report presents a new approach to closed loop controlled ventilation, called Adaptive Lung Ventilation (ALV). ALV is based on a pressure controlled ventilation mode suitable for paralyzed, as well as spontaneously breathing, subjects. The clinician enters a desired gross alveolar ventilation (V'gA in l/min), and the ALV controller tries to achieve this goal by automatic adjustment of mechanical rate and inspiratory pressure level. The adjustments are based on measurements of the patient's lung mechanics and series dead space. The ALV controller was tested on a physical lung model with adjustable mechanical properties. Three different lung pathologies were simulated on the lung model to test the controller for rise time (T90), overshoot (Ym), and steady state performance (delta max). The pathologies corresponded to restrictive lung disease (similar to ARDS), a "normal" lung, and obstructive lung disease (such as asthma). Furthermore, feasibility tests were done in 6 patients undergoing surgical procedures in total intravenous anesthesia. In the model studies, the controller responded to step changes between 48 seconds and 81 seconds. It did exhibit an overshoot between 5.5% and 7.9% of the setpoint after the step change.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8200668

Laubscher, T P; Heinrichs, W; Weiler, N; Hartmann, G; Brunner, J X

1994-01-01

50

Liquid Ventilation  

PubMed Central

Mammals have lungs to breathe air and they have no gills to breath liquids. When the surface tension at the air-liquid interface of the lung increases, as in acute lung injury, scientists started to think about filling the lung with fluid instead of air to reduce the surface tension and facilitate ventilation. Liquid ventilation (LV) is a technique of mechanical ventilation in which the lungs are insufflated with an oxygenated perfluorochemical liquid rather than an oxygen-containing gas mixture. The use of perfluorochemicals, rather than nitrogen, as the inert carrier of oxygen and carbon dioxide offers a number of theoretical advantages for the treatment of acute lung injury. In addition, there are non-respiratory applications with expanding potential including pulmonary drug delivery and radiographic imaging. The potential for multiple clinical applications for liquid-assisted ventilation will be clarified and optimized in future.

Tawfic, Qutaiba A.; Kausalya, Rajini

2011-01-01

51

Noninvasive ventilation after intubation and mechanical ventilation  

Microsoft Academic Search

Noninvasive ventilation after intubation and mechanical ventilation. M. Ferrer, O. Bernadich, S. Nava, A. Torres. #ERS Journals Ltd 2002. ABSTRACT: Patients with chronic airflow obstruction who are difficult to wean from mechanical ventilation are at increased risk of intubation-associated complications and mortality because of prolonged invasive mechanical ventilation. Noninvasive positive pressure ventilation may revert most of the pathophysiological mechanisms associated

M. Ferrer; O. Bernadich; S. Nava; A. Torres

2002-01-01

52

Effects of a modified live CSFV vaccine on the development of PMWS in pigs infected experimentally with PCV2  

Microsoft Academic Search

The objective of this study was to determine the effect of vaccination against classical swine fever virus (CSFV) on the development of postweaning multisystemic wasting syndrome (PMWS) in conventional pigs infected experimentally with porcine circovirus type 2 (PCV-2). The pigs infected with PCV-2 and immunised with modified live CSFV developed mild to moderate PMWS, whereas none of the pigs infected

Y. Ha; E. M. Lee; Y. H. Lee; C. H. Kim; D. Kim; S. Chae; K. K. Ahn; B. Kim; C. Chae

2009-01-01

53

Review of Residential Ventilation Technologies  

SciTech Connect

This paper reviews current and potential ventilation technologies for residential buildings in North America and a few in Europe. The major technologies reviewed include a variety of mechanical systems, natural ventilation, and passive ventilation. Key parameters that are related to each system include operating costs, installation costs, ventilation rates, heat recovery potential. It also examines related issues such as infiltration, duct systems, filtration options, noise, and construction issues. This report describes a wide variety of systems currently on the market that can be used to meet ASHRAE standard 62.2. While these systems generally fall into the categories of supply, exhaust or balanced, the specifics of each system are driven by concerns that extend beyond those in the standard and are discussed. Some of these systems go beyond the current standard by providing additional features (such as air distribution or pressurization control). The market will decide the immediate value of such features, but ASHRAE may wish to consider modifications to the standard in the future.

Russell, Marion L.; Sherman, Max H.; Rudd, Armin

2005-03-01

54

Nasal ventilation.  

PubMed Central

Nasal intermittent positive pressure ventilation is likely to have an increasing role in the management of acute ventilatory failure, weaning, and chronic ventilatory problems. Further improvements in ventilator and mask design will be seen. Appropriate application is likely to reduce both mortality and admissions to intensive care, while domiciliary use can improve life expectancy and/or quality of life in chronic ventilatory disorders. As with any new technique, enthusiasm should not outweigh clear outcome information, and possible new indications should always be subject to careful assessment. Images Figure 2

Simonds, A. K.

1998-01-01

55

112. REFRIGERANT CONDENSER TANKS AND PRESSURE CONTROLS IN NORTHEAST CORNER ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

112. REFRIGERANT CONDENSER TANKS AND PRESSURE CONTROLS IN NORTHEAST CORNER OF MECHANICAL EQUIPMENT ROOM (201), LSB (BLDG. 751) - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

56

Model Program Boosts Blood-Pressure Control for Patients  

MedlinePLUS

... cardiovascular risk reduction program for Kaiser Permanente Northern California. From 2001 through 2009, the blood-pressure control ... adults to about 652,000 among Kaiser's Northern California facilities. The average age of patients was 63. ...

57

[Effect of endoscopic surgery techniques in children on ventilation].  

PubMed

The purpose of our study was to show the effects of laparoscopic procedures on the ventilation of children. We measured an increase of ventilation pressures (Pmax, Ppfat and Pmean) of 28, 35 and 48% respectively. petCO2 rose from 35 to 41 +/- 2 mmHg. There was no loss of body temperature in any child. Laparoscopic procedures as seen here for appendectomy or diagnostic exploration in children of 13.5 kg body weight or more caused no problems that were clinically evident. The increase of ventilation pressure could be attenuated by choosing the parameters of ventilation (e.g. flow, I:E ratio) in such a way that Pmax does not exceed 20 mbar. Alternatively, pressure-controlled ventilation may be used, adjusting petCO2 by ventilation frequency. In any case there must be a strict control of all possible side effects of laparoscopy, such as cutaneous emphysema or pneumothorax. PMID:9333328

Schäfer, R; Gerlach, K; Barthel, M; Schmucker, P

1997-06-01

58

Emergence of a novel mutant PCV2b variant associated with clinical PCVAD in two vaccinated pig farms in the U.S. concurrently infected with PPV2.  

PubMed

Porcine circovirus (PCV) type 2b (PCV2b) emerged in North America in 2005-2006. During May of 2012, PCVAD occurred in 10-18-week-old pigs in two farms within a production system that routinely vaccinated against PCV2. Both farms received replacement gilts from the same multiplier. A mutant PCV2b strain not previously present in North America was identified. The strain was found to be 99.9% identical to a recently described mutant PCV2 isolate reported in China in 2010 and thought to be more virulent than classical PCV2a or PCV2b strains. It is possible that the current PCV2a-based commercial vaccines are not fully protective against this new strain. In addition, emerging porcine parvovirus type 2 (PPV2) was detected in 55% of the serum samples (73/132), perhaps implying that PPV2 could be a cofactor in cases of PCVAD. PMID:23305615

Opriessnig, Tanja; Xiao, Chao-Ting; Gerber, Priscilla F; Halbur, Patrick G

2012-12-22

59

Calibration of seven ICU ventilators for mechanical ventilation with helium-oxygen mixtures.  

PubMed

The study evaluated seven intensive care unit (ICU) ventilators (Veolar FT, Galileo, Evita 2, Evita 4, Servo 900C, Servo 300, Nellcor Puritan Bennett 7200 Series) with helium-oxygen (HeO2), using a lung model, to develop correction factors for the safe use of HeO2. A 70:28 helium-O2 mixture (heliox) replaced air and combined with O2 (HeO2). Theoretical impact of HeO2 on inspiratory valves and gas mixing was computed. True fraction of inspired oxygen (FIO2del) was compared with fraction of inspired oxygen (FIO2) set on the ventilator (FIO2set). True tidal volume (VTdel) was compared with VT set on the ventilator (VTset) in volume control and with control VTdel at FIO2 1.0 in pressure control. FIO2del minimally exceeded FIO2set ( FIO2set by 125%). In volume control, with the Veolar FT, Galileo, Evita 2, and Servo 900C, VTdel > VTset, with the 7200 Series VTdel < VTset (linear relationship, magnitude of discrepancy inversely related to FIO2set). With the Evita 4, VTdel > VTset (nonlinear relationship), whereas with the Servo 300 VTdel = VTset. In pressure control, VTdel was identical to control measurements, except with the 7200 Series (ventilator malfunction). Correction factors were developed that can be applied to most ventilators. PMID:10390375

Tassaux, D; Jolliet, P; Thouret, J M; Roeseler, J; Dorne, R; Chevrolet, J C

1999-07-01

60

Ventilated Supercavities  

NASA Astrophysics Data System (ADS)

Drag reduction and/or speed augmentation of marine vehicles by means of supercavitation is a topic of great interest. During the initial launch of a supercavitating vehicle, ventilation is required to supply an artificial cavity until conditions at which a natural supercavity can be sustained are reached. A study has been carried out to determine various aspects of the flow physics of a supercavitating vehicle at Saint Anthony Falls Laboratory. During the present experimental work, the ventilated supercavity formed behind a sharp-edged disk was investigated using several configurations. Results regarding cavity shape and closure, as well as ventilation requirements versus cavitation number and Froude number are presented. In addition, effects related to flow choking in a water tunnel test section are discussed. Results obtained are similar in character to previously reported results, but differ significantly in measured values. An attempt was made to correlate results from water tunnel experiments to open flows, where there are no effects of flow choking. Supercavitation parameters, especially the minimum attainable cavitation number are found to be strongly affected by tunnel blockage and Froude number.

Kawakami, Ellison; Arndt, Roger

2011-11-01

61

Ventilated Supercavities  

NASA Astrophysics Data System (ADS)

The topic of supercavitation is of considerable interest to drag reduction and/or speed augmentation in marine vehicles. Supercavitating vehicles need to be supplied with an artificial cavity through ventilation until they accelerate to conditions at which a natural supercavity can be sustained. A study has been carried out in the high-speed water tunnel at St. Anthony Falls Laboratory to investigate some aspects of the flow physics of such a supercavitating vehicle. During the present experimental work, the ventilated supercavity formed behind a sharp-edged disk was investigated utilizing several different configurations. Results regarding cavity shape, cavity closure and ventilation requirements versus cavitation number and Froude number are presented. Additionally, effects related to flow choking in a water tunnel test section are discussed. Results obtained are similar in character to previously reported results, but differ significantly in measured values. Cavity shape, particularly aft of the maximum cavity diameter, is found to be a strong function of the model support scheme chosen.

Kawakami, Ellison; Arndt, Roger

2009-11-01

62

Postweaning multisystemic wasting syndrome (PMWS) in the Philippines: porcine circovirus type 2 (PCV2) detection and characterization.  

PubMed

Four swine facilities located in Northern Luzon, in the Philippines, showed lesions and clinical signs similar to those described in post weaning multisystemic wasting syndrome (PMWS). Post-mortem and histopathological examination revealed the presence of typical lymphoid lesions caused by porcine circovirus type 2 (PCV2). An in situ hybridization (ISH) technique allowed the detection of PCV2 nucleic acid associated with the lesions in target tissues. PCV2 DNA from paraffin embedded tissues was extracted, purified and sequenced. The phylogenetic analysis of the sequences obtained confirmed their identity, and grouped them into a PCV2 subgroup, together with some Canadian, French and Dutch isolates. This report is the first description of the presence of PMWS in the Philippines. PMID:15187364

Maldonado, Jaime; Ségales, Joaquim; Calsamiglia, Maria; Llopart, David; Sibila, Marina; Lapus, Zoilo; Riera, Pere; Artigas, Carlos

2004-05-01

63

Kitchen ventilation  

SciTech Connect

Kitchen ventilation is a subject that has not received the attention that has been given to more glamorous HVAC and R topics. Consequently, its theoretical and technical development has not advanced like these topics. However, a group has been working within the ASHRAE Technical Committee (TC) and Task Group (TG) framework to correct this situation. The group is TG5.KV and it achieved TG status last year after starting as an informal group and then a sub-committee of TC9.8. One of its efforts has been to write a Handbook chapter, which will appear in the 1995 ASHRAE Handbook -- Applications. This article is a survey of that chapter.

Kelso, R.M. [Univ. of Tennessee, Knoxville, TN (United States). College of Architecture; Rousseau, C. [Newcomb and Boyd Consulting Engineers, Atlanta, GA (United States)

1995-09-01

64

142. STANDBY PRESSURE CONTROL UNIT FOR FUEL AND LIQUID OXYGEN ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

142. STANDBY PRESSURE CONTROL UNIT FOR FUEL AND LIQUID OXYGEN IN SOUTHWEST PORTION OF CONTROL ROOM (214), LSB (BLDG. 751), FACING WEST - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

65

Hydraulic fracturing after water pressure control blasting for increased fracturing  

Microsoft Academic Search

Traditional hydraulic fracturing techniques generally form main hydraulic cracks and airfoil branch fissures, but main hydraulic cracks are relatively few in number. Hydraulic fracturing after water pressure control blasting can transform the structure of coal and rock mass. Experiments prove that it is an effective method for increasing the number and range of hydraulic cracks, as well as for improving

Bingxiang Huang; Changyou Liu; Junhui Fu; Hui Guan

2011-01-01

66

Ventilation Effectiveness - A Guide to Efficient Ventilation.  

National Technical Information Service (NTIS)

A two-zone mixing model describes the concept(s) of and defines the effectiveness of ventilation. Multiroom aspects and procedures for measuring ventilation effectiveness are dealt with. The simple two-zone model, experimentally verified by laboratory tes...

E. Skaaret H. M. Mathisen

1983-01-01

67

A live-attenuated chimeric PCV2 vaccine based on subtype 2b is transmitted to contact pigs but is not upregulated by concurrent infection with PPV and PRRSV and is efficacious in a triple challenge co-infection model  

Technology Transfer Automated Retrieval System (TEKTRAN)

The objective of this study was to determine the safety and efficacy of a new live-attenuated chimeric PCV1/2b vaccine. Forty-six, 21-day-old, PCV2-naïve pigs were randomly assigned to one of six groups (Negative controls, positive controls, Vac-0, Vac-0-PCV2, Contact-PCV2, Vac-28-PCV2). All pigs we...

68

Porcine circovirus type 2 (PCV2) infection decreases the efficacy of an attenuated classical swine fever virus (CSFV) vaccine  

PubMed Central

The Lapinized Philippines Coronel (LPC) vaccine, an attenuated strain of classical swine fever virus (CSFV), is an important tool for the prevention and control of CSFV infection and is widely and routinely used in most CSF endemic areas, including Taiwan. The aim of this study was to investigate whether PCV2 infection affects the efficacy of the LPC vaccine. Eighteen 6-week-old, cesarean-derived and colostrum-deprived (CDCD), crossbred pigs were randomly assigned to four groups. A total of 105.3 TCID50 of PCV2 was experimentally inoculated into pigs through both intranasal and intramuscular routes at 0 days post-inoculation (dpi) followed by LPC vaccination 12 days later. All the animals were challenged with wild-type CSFV (ALD stain) at 27 dpi and euthanized at 45 dpi. Following CSFV challenge, the LPC-vaccinated pigs pre-inoculated with PCV2 showed transient fever, viremia, and viral shedding in the saliva and feces. The number of IgM+, CD4+CD8-CD25+, CD4+CD8+CD25+, and CD4-CD8+CD25+ lymphocyte subsets and the level of neutralizing antibodies against CSFV were significantly higher in the animals with LPC vaccination alone than in the pigs with PCV2 inoculation/LPC vaccination. In addition, PCV2-derived inhibition of the CSFV-specific cell proliferative response of peripheral blood mononuclear cells (PBMCs) was demonstrated in an ex vivo experiment. These findings indicate that PCV2 infection decreases the efficacy of the LPC vaccine. This PCV2-derived interference may not only allow the invasion of wild-type CSFV in pig farms but also increases the difficulty of CSF prevention and control in CSF endemic areas.

2011-01-01

69

Nasopharyngeal carriage of individual Streptococcus pneumoniae serotypes during pediatric radiologically confirmed community acquired pneumonia following PCV7 introduction in Switzerland  

PubMed Central

Background Community-acquired pneumonia (CAP) is a serious cause of morbidity among children in developed countries. The real impact of 7-valent pneumococcal conjugate vaccine (PCV7) on pneumococcal pneumonia is difficult to assess accurately. Methods Children aged ?16 years with clinical and radiological pneumonia were enrolled in a multicenter prospective study. Children aged ?16 years admitted for a minor elective surgery was recruited as controls. Nasopharyngeal samples for PCR serotyping of S. pneumoniae were obtained in both groups. Informations on age, gender, PCV7 vaccination status, day care/school attendance, siblings, tobacco exposure were collected. Results In children with CAP (n=236), 54% of the nasopharyngeal swabs were PCR-positive for S. pneumoniae compared to 32% in controls (n=105) (p=0.003). Serotype 19A was the most common pneumococcal serotype carried in children with CAP (13%) and in controls (15%). Most common serotypes were non-vaccine types (39.4% for CAP and 47.1% for controls) and serotypes included only in PCV13 (32.3% for CAP and 23.5% for controls). There was no significant difference in vaccine serotype distribution between the two groups. In fully vaccinated children with CAP, the proportion of serotypes carried only in PCV13 was higher (51.4%) than in partially vaccinated or non vaccinated children (27.6% and 28.6% respectively, p=0.037). Conclusions Two to 4 years following introduction of PCV7, predominant S. pneumoniae serotypes carried in children with CAP were non PCV7 serotypes, and the 6 new serotypes included in PCV13 accounted for 51.4% of carried serotypes in fully vaccinated children.

2013-01-01

70

Better blood pressure control: how to combine drugs  

Microsoft Academic Search

Prospective comparisons of different drug classes have shown that differences in blood pressure control, rather than differences between drug classes, have the over-riding influence on overall outcome. The same studies have also reinforced the need, in the majority of patients, to use combinations of drugs in order to achieve the target of <140\\/85 mmHg. By contrast, most patients in routine

M J Brown; J K Cruickshank; A F Dominiczak; G A MacGregor; N R Poulter; G I Russell; S Thom; B Williams

2003-01-01

71

Better blood pressure control: how to combine drugs  

Microsoft Academic Search

Prospective comparisons of different drug classes have shown that differences in blood pressure control, rather than differences between drug classes, have the over- riding influence on overall outcome. The same studies have also reinforced the need, in the majority of patients, to use combinations of drugs in order to achieve the target of o140\\/85 mmHg. By contrast, most patients in

MJ Brown; JK Cruickshank; AF Dominiczak; GA MacGregor; NR Poulter; GI Russell; S Thom; B Williams

72

VENTILATION NEEDS DURING CONSTRUCTION  

SciTech Connect

The purpose of this analysis is to determine ventilation needs during construction and development of the subsurface repository and develop systems to satisfy those needs. For this analysis, construction is defined as pre-emplacement excavation and development is excavation that takes place simultaneously with emplacement. The three options presented in the ''Overall Development and Emplacement Ventilation Systems'' analysis (Reference 5.5) for development ventilation will be applied to construction ventilation in this analysis as well as adding new and updated ventilation factors to each option for both construction and development. The objective of this analysis is to develop a preferred ventilation system to support License Application Design. The scope of this analysis includes: (1) Description of ventilation conditions; (2) Ventilation factors (fire hazards, dust control, construction logistics, and monitoring and control systems); (3) Local ventilation alternatives; (4) Global ventilation options; and (5) Evaluation of options.

C.R. Gorrell

1998-07-23

73

Efficacy of single dose of an inactivated porcine circovirus type 2 (PCV2) whole-virus vaccine with oil adjuvant in piglets  

PubMed Central

Background Post-weaning multisystemic wasting syndrome (PMWS) associated with PCV2 is one of the most costly diseases currently faced by the swine industry. The development of effective vaccines against PCV2 infection has been accepted as an important strategy in the prophylaxis of PMWS. Methods In the present study, a PK-15 cell-adapted formalin-inactivated prototype vaccine candidate was prepared using a strain of PCV2 from China. Inactivation of the virus was accomplished using a standard formalin inactivation protocol. The protective properties of the inactivated PCV2 vaccine were evaluated in piglets. Ten 28-day-old pigs were randomly assigned to two groups, each with five. Group 1 was vaccinated intramuscularly with the inactivated virus preparation; Group 2 received sterile PBS as a placebo. By 28?days post-vaccination (DPV), Groups 1 and 2 were challenged intranasally and intramuscularly with 5?×?107 TCID50 of a virulent PCV2 isolate. Results The vaccinated pigs seroconverted to PCV2 and had high levels of serum antibodies to PCV2 at 28?days after vaccination, whereas the control pigs remained seronegative. No significant signs of clinical disease were recorded following the challenge with PCV2, but moderate amounts of PCV2 antigen were detected in most lymphoid organs of the control pigs. PCV2 was detected in two out of the five vaccinated pigs. Furthermore, pathological lesions and viremia were milder in the vaccinated group. Conclusions The obtained results indicate that the inactivated PCV2 virus vaccine with an oil adjuvant induce an immunological response in pigs that appears to provide protection from infection with PCV2. The vaccine, therefore, may have the potential to serve as a vaccine aimed to protect pigs from developing PMWS.

2012-01-01

74

A Live-Attenuated Chimeric Porcine Circovirus Type 2 (PCV2) Vaccine Is Transmitted to Contact Pigs but Is Not Upregulated by Concurrent Infection with Porcine Parvovirus (PPV) and Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) and Is Efficacious in a PCV2b-PRRSV-PPV Challenge Model?  

PubMed Central

The live chimeric porcine circovirus type 2 (PCV2) vaccine with the capsid gene of the emerging subtype 2b cloned in the genomic backbone of the nonpathogenic PCV1 is attenuated in vivo and induces protective immunity against PCV2. To further determine the safety and efficacy of this experimental vaccine, we tested for evidence of pig-to-pig transmission by commingling nonvaccinated and vaccinated pigs, determined potential upregulation by simultaneous vaccination and infection with porcine parvovirus (PPV) and porcine reproductive and respiratory syndrome virus (PRRSV), and determined vaccine efficacy by challenging pigs 4 weeks after vaccination with PCV2b, PRRSV, and PPV. Forty-six 21-day-old, PCV2-naïve pigs were randomly assigned to one of six groups. Twenty-nine of 46 pigs were challenged with PCV2b, PRRSV, and PPV at day 28, 8/46 remained nonvaccinated and nonchallenged and served as negative controls, and 9/46 remained nonchallenged and served as vaccination controls. All animals were necropsied at day 49. PCV1-PCV2 viremia was detected in nonvaccinated contact pigs commingled with vaccinated pigs, indicating pig-to-pig transmission; however, PCV1-PCV2 DNA levels remained low in all vaccinated and contact pigs regardless of concurrent infection. Finally, vaccination 28 days before challenge resulted in significantly (P < 0.05) decreased amounts of PCV2 in tissues and sera and significantly (P < 0.05) reduced macroscopic and microscopic lesions. The results of this study indicate that the experimental live-attenuated chimeric PCV2 vaccine, although transmissible to contact pigs, remains attenuated in pigs concurrently infected with PRRSV and PPV and induces protective immunity against PCV2b when it is administered 28 days before PCV2 exposure.

Opriessnig, T.; Shen, H. G.; Pal, N.; Ramamoorthy, S.; Huang, Y. W.; Lager, K. M.; Beach, N. M.; Halbur, P. G.; Meng, X. J.

2011-01-01

75

Clonal Distribution of Common Pneumococcal Serotypes Not Included in the 7-Valent Conjugate Vaccine (PCV7): Marked Differences between Two Ethnic Populations in Southern Israel  

PubMed Central

This study aimed to compare the clonal distribution of common pneumococcal strains not included in the 7-valent pneumococcal conjugate vaccine (PCV7) that were isolated from cases of acute otitis media (AOM) and invasive pneumococcal disease (IPD) in two distinct ethnic populations in southern Israel during the decade (1999 to 2008) preceding PCV7 implementation. Isolates recovered from Jewish and Bedouin children <5 years old were characterized by antibiotic resistance and molecular epidemiology using pulsed-field gel electrophoresis and multilocus sequence typing. Of 5,236 AOM and 425 IPD isolates, 43% and 57% were from Jewish and Bedouin children, respectively. PCV7 accounted for 54% and 45% of the AOM and IPD episodes, respectively. Eleven major non-PCV7 serotypes (1, 3, 5, 6A, 7F, 12F, 15B/C, 19A, 21, 33F, and 35B) constituted 31% and 42% of the AOM and IPD episodes, respectively. The clonal distributions of the 11 non-PCV7 serotypes and their antibiotic susceptibilities were significantly different among the two ethnic populations in both the AOM and IPD groups. About half of the AOM and IPD cases resulted from non-PCV7 pneumococci, even before PCV7 implementation. The significant differences between the two ethnic populations suggest that lifestyle and microenvironment are major determinants in the clonal distribution of disease-causing pneumococci. Post-PCV7 surveillance is important in understanding non-PCV7 clonal expansion in the two distinct populations.

Benisty, Rachel; Trefler, Ronit; Givon-Lavi, Noga; Dagan, Ron

2012-01-01

76

Clonal distribution of common pneumococcal serotypes not included in the 7-valent conjugate vaccine (PCV7): marked differences between two ethnic populations in southern Israel.  

PubMed

This study aimed to compare the clonal distribution of common pneumococcal strains not included in the 7-valent pneumococcal conjugate vaccine (PCV7) that were isolated from cases of acute otitis media (AOM) and invasive pneumococcal disease (IPD) in two distinct ethnic populations in southern Israel during the decade (1999 to 2008) preceding PCV7 implementation. Isolates recovered from Jewish and Bedouin children <5 years old were characterized by antibiotic resistance and molecular epidemiology using pulsed-field gel electrophoresis and multilocus sequence typing. Of 5,236 AOM and 425 IPD isolates, 43% and 57% were from Jewish and Bedouin children, respectively. PCV7 accounted for 54% and 45% of the AOM and IPD episodes, respectively. Eleven major non-PCV7 serotypes (1, 3, 5, 6A, 7F, 12F, 15B/C, 19A, 21, 33F, and 35B) constituted 31% and 42% of the AOM and IPD episodes, respectively. The clonal distributions of the 11 non-PCV7 serotypes and their antibiotic susceptibilities were significantly different among the two ethnic populations in both the AOM and IPD groups. About half of the AOM and IPD cases resulted from non-PCV7 pneumococci, even before PCV7 implementation. The significant differences between the two ethnic populations suggest that lifestyle and microenvironment are major determinants in the clonal distribution of disease-causing pneumococci. Post-PCV7 surveillance is important in understanding non-PCV7 clonal expansion in the two distinct populations. PMID:22875896

Porat, Nurith; Benisty, Rachel; Trefler, Ronit; Givon-Lavi, Noga; Dagan, Ron

2012-08-08

77

Intensive Blood-Pressure Control in Hypertensive Chronic Kidney Disease  

PubMed Central

BACKGROUND In observational studies, the relationship between blood pressure and end-stage renal disease (ESRD) is direct and progressive. The burden of hypertension-related chronic kidney disease and ESRD is especially high among black patients. Yet few trials have tested whether intensive blood-pressure control retards the progression of chronic kidney disease among black patients. METHODS We randomly assigned 1094 black patients with hypertensive chronic kidney disease to receive either intensive or standard blood-pressure control. After completing the trial phase, patients were invited to enroll in a cohort phase in which the blood-pressure target was less than 130/80 mm Hg. The primary clinical outcome in the cohort phase was the progression of chronic kidney disease, which was defined as a doubling of the serum creatinine level, a diagnosis of ESRD, or death. Follow-up ranged from 8.8 to 12.2 years. RESULTS During the trial phase, the mean blood pressure was 130/78 mm Hg in the intensive-control group and 141/86 mm Hg in the standard-control group. During the cohort phase, corresponding mean blood pressures were 131/78 mm Hg and 134/78 mm Hg. In both phases, there was no significant between-group difference in the risk of the primary outcome (hazard ratio in the intensive-control group, 0.91; P = 0.27). However, the effects differed according to the baseline level of proteinuria (P = 0.02 for interaction), with a potential benefit in patients with a protein-to-creatinine ratio of more than 0.22 (hazard ratio, 0.73; P = 0.01). CONCLUSIONS In overall analyses, intensive blood-pressure control had no effect on kidney disease progression. However, there may be differential effects of intensive blood-pressure control in patients with and those without baseline proteinuria. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases, the National Center on Minority Health and Health Disparities, and others.)

Appel, Lawrence J.; Wright, Jackson T.; Greene, Tom; Agodoa, Lawrence Y.; Astor, Brad C.; Bakris, George L.; Cleveland, William H.; Charleston, Jeanne; Contreras, Gabriel; Faulkner, Marquetta L.; Gabbai, Francis B.; Gassman, Jennifer J.; Hebert, Lee A.; Jamerson, Kenneth A.; Kopple, Joel D.; Kusek, John W.; Lash, James P.; Lea, Janice P.; Lewis, Julia B.; Lipkowitz, Michael S.; Massry, Shaul G.; Miller, Edgar R.; Norris, Keith; Phillips, Robert A.; Pogue, Velvie A.; Randall, Otelio S.; Rostand, Stephen G.; Smogorzewski, Miroslaw J.; Toto, Robert D.; Wang, Xuelei

2013-01-01

78

Dietary calcium intake: effects on central blood pressure control.  

PubMed

Low dietary intake of calcium has been found to be a risk factor for the development of hypertension in a number of epidemiological studies. Moreover, increased dietary calcium intake has been reported to beneficially influence on blood pressure in both humans and animal models of hypertension, suggesting the relative calcium deficiency may indeed be present in these conditions. The underlying mechanisms for the beneficial effect of positive calcium balance on blood pressure have been a subject for extensive research in essential and experimental hypertension. In this article, the possible beneficial effects of increased dietary calcium intake on central blood pressure control are reviewed. PMID:8588115

Pörsti, I; Mäkynen, H

1995-11-01

79

Ventilation Strategies for Different Climates.  

National Technical Information Service (NTIS)

Until recently, residential ventilation in the United States has been provided by infiltration. In this report we compare natural ventilation (ventilation by infiltration) with several mechanical ventilation strategies and examine the overall energy consu...

H. E. Feustel M. P. Modera A. H. Rosenfeld

1987-01-01

80

Learning about ventilators  

MedlinePLUS

... mouth or anopening through their neck into the trachea (windpipe). A ventilator may also be referred to ... a tube that connects the ventilator to the trachea). Suctioning is a word you will hear a ...

81

Pressure modes of mechanical ventilation: the good, the bad, and the ugly.  

PubMed

Numerous pressure modes are currently available on ventilators. The application of microprocessor technology has resulted in sophisticated mode options that are very responsive to patient-initiated efforts, yet little is known about how to use the modes or their effect on patient outcomes. This article describes a wide variety of pressure modes including traditional modes such as pressure support and pressure-controlled ventilation in addition to less traditional new modes such as airway pressure release ventilation, biphasic positive airway pressure, Pressure Augmentation (Bear 1000, Viasys Healthcare, Yorba Linda, California), Volume Support (Maquet, Bridgewater, New Jersey), Pressure Regulated Volume Control (Maquet, Bridgewater, New Jersey), Volume Ventilation Plus (Puritan Bennett, Boulder, Colorado), Adaptive Support Ventilation (Hamilton Medical, Switzerland), and Proportional Assist Ventilation (Dräger Medical, Richmond Hill, Ontario, Canada). The "good, the bad, and the ugly" issues surrounding the application, evaluation, and outcomes of the modes are discussed. PMID:18981742

Burns, Suzanne M

82

Mechanical ventilation for the home  

Microsoft Academic Search

A ventilation system gives occupants control over a home`s air change rate and thermal control. This article discussed the option available today for good mechanical ventilation. Topic covered include ventilation codes; types of ventilation; ventilation approaches (fan types, heat recovery ventilation); avoid backdrafting; meeting outdoor air requirements; sizing fans; ducts and terminal devices; timers and other controls. 3 tabs.

1996-01-01

83

The Relationship of Diet to Blood Pressure Control  

PubMed Central

Sodium restriction has become an integral part of the medical management of hypertension. In general the degree of sodium restriction recommended by physicians depends upon the severity of the disease. The commonly prescribed sodium restricted diets are classified as mild and moderate. Mild sodium restriction refers to a diet in which 3.0-4.0 gm of sodium are allowed per day. Moderate sodium restriction is indicated when hypertension is more severe; 1-2 gm of sodium are allowed daily. Sodium added in the processing of foods contributes significantly to the sodium content of the diet. “Convenience” and “fast” foods are high in sodium and are not allowed the hypertensive patients. Significant advances have occurred in the past decade in the medical management of hypertension. The sodium-restricted diet remains the cornerstone of effective blood pressure control. Therefore, nutrition must become an integral part of the hypertensive treatment program.

Jones, Walretta O.; Brown, Jay

1979-01-01

84

The financial cost of optimising blood pressure control.  

PubMed

We have investigated the financial costs of attempts to optimise blood pressure control in patients referred to our blood pressure clinic. At first referral, the average blood pressure in the 262 patients studied were 167/97 mmHg and the monthly costs of the antihypertensive drugs was 23.44 pounds. After 1 year of clinic attendance, the blood pressure was reduced to 149/87 mmHg, and the average drug costs had risen to 30.68 pounds. For drug expenditure alone, the cost of reducing systolic blood pressure by 1 mmHg was 0.36p pounds (Euro 0.55, USD 0.55) and for diastolic blood pressure the cost-was 0.72p pounds (Euro 1.12, USD 1.13). PMID:15372065

Shiner, T; Simons, L; Parkinson, H; Khanbhai, A; Karthikeyan, V J; Karthikeyen, V J; Nandhara, G; Beevers, D G

2005-01-01

85

Patient-ventilator asynchrony during assisted mechanical ventilation  

Microsoft Academic Search

Objective  The incidence, pathophysiology, and consequences of patient-ventilator asynchrony are poorly known. We assessed the incidence of patient-ventilator asynchrony during assisted mechanical ventilation and we identified associated factors.Methods  Sixty-two consecutive patients requiring mechanical ventilation for more than 24?h were included prospectively as soon as they triggered all ventilator breaths: assist-control ventilation (ACV) in 11 and pressure-support ventilation (PSV) in 51.Measurements  Gross asynchrony detected

Arnaud W. Thille; Pablo Rodriguez; Belen Cabello; François Lellouche; Laurent Brochard

2006-01-01

86

[Complications of mechanical ventilation].  

PubMed

Mechanical ventilation of the lungs, as an important therapeutic measure, cannot be avoided in critically ill patients. However, when machines take over some of vital functions there is always a risk of complications and accidents. Complications associated with mechanical ventilation can be divided into:1) airway-associated complications; 2) complications in the response of patients to mechanical ventilation; and 3) complications related to the patient's response to the device for mechanical ventilation. Complications of artificial airway may be related to intubation and extubation or the endotracheal tube. Complications of mechanical ventilation, which arise because of the patient's response to mechanical ventilation, may primarily cause significant side effects to the lungs. During the last two decades it was concluded that mechanical ventilation can worsen or cause acute lung injury. Mechanical ventilation may increase the alveolar/capillary permeability by overdistension of the lungs (volutrauma), it can exacerbate lung damage due to the recruitment/derecruitment of collapsed alveoli (atelectrauma) and may cause subtle damages due to the activation of inflammatory processes (biotrauma). Complications caused by mechanical ventilation, beside those involving the lungs, can also have significant effects on other organs and organic systems, and can be a significant factor contributing to the increase of morbidity and mortality in critically ill of mechanically ventilated patients. Complications are fortunately rare and do not occur in every patient, but due to their seriousness and severity they require extensive knowledge, experience and responsibility by healthcare workers. PMID:22070009

Draškovi?, Biljana; Raki?, Goran

87

Inspiratory oscillatory flow with a portable ventilator: a bench study  

PubMed Central

Introduction We observed an oscillatory flow while ventilating critically ill patients with the Dräger Oxylog 3000™ transport ventilator during interhospital transfer. The phenomenon occurred in paediatric patients or in adult patients with severe airway obstruction ventilated in the pressure-regulated or pressure-controlled mode. As this had not been described previously, we conducted a bench study to investigate the phenomenon. Methods An Oxylog 3000™ intensive care unit ventilator and a Dräger Medical Evita-4 NeoFlow™ intensive care unit ventilator were connected to a Dräger Medical LS800™ lung simulator. Data were registered by a Datex-S5™ Monitor with a D-fend™ flow and pressure sensor, and were analysed with a laptop using S5-Collect™ software. Clinical conditions were simulated using various ventilatory modes, using various ventilator settings, using different filters and endotracheal tubes, and by changing the resistance and compliance. Data were recorded for 258 combinations of patient factors and respirator settings to detect thresholds for the occurrence of the phenomenon and methods to overcome it. Results Under conditions with high resistance in pressure-regulated ventilation with the Oxylog 3000™, an oscillatory flow during inspiration produced rapid changes of the airway pressure. The phenomenon resulted in a jerky inspiration with high peak airway pressures, higher than those set on the ventilator. Reducing the inspiratory flow velocity was effective to terminate the phenomenon, but resulted in reduced tidal volumes. Conclusion Oscillatory flow with potentially harmful effects may occur during ventilation with the Dräger Oxylog 3000™, especially in conditions with high resistance such as small airways in children (endotracheal tube internal diameter <6 mm) or severe obstructive lung diseases or airway diseases in adult patients.

Frank, Guenther E; Trimmel, Helmut; Fitzgerald, Robert D

2005-01-01

88

[Blood pressure control in the area of surgical interventions].  

PubMed

For specific surgical interventions, such as aortic stent implantation, it might be temporarily necessary to decrease mean arterial pressure to rather low levels (around 40 mm Hg). Such hypotensive pressure levels are necessary to avoid intra- and postoperative intricacies. Traditionally, the drug Nitroprussidnatrium is used for this task. To adjust the correct amount of drug to reach the target pressure as fast as possible and without overshoot, the anaesthetists typically use empirical knowledge and might need several minutes until the target point is reached. In our research group, an adaptive control system was developed for this task which is able to compute and set the transient drug release automatically. For the design and testing of the adaptive control strategy, the well known Guyton model was implemented into the MATLAB/Simulink development environment. This paper describes the implementation and adaption of the Guyton model to hypotensive pressure control and provides some algorithmic details of the adaptive control strategy for automatic drug delivery in deep hypotension. The designed control system was successfully validated in animal trials (25 trials on 7 pigs). Following this, an additional controller component for increase of blood pressure with the help of the drug Noradrenalin was implemented. It is now possible to increase blood pressure to a specific value to save defined cerebral perfusion pressure for patients with craniocerebral injury. In a second pilot trial, this controller extension was tested in 10 pigs. PMID:19807293

Simanski, Olaf; Janda, Matthias; Bajorat, Jörn; Nguyen, Ngon C; Hofmockel, Rainer; Lampe, Bernhard P

2009-10-01

89

[New concepts for pressure-controlled glaucoma implants].  

PubMed

In industrialized countries glaucoma is one of the most common causes that leads to blindness. It is also the most common cause of irreversible blindness worldwide. In addition to local treatment of intraocular pressure and filtering glaucoma surgery, alloplastic implants are increasingly being used in glaucoma therapy. As long-term results published in the literature of commonly used implants are unsatisfactory, it seems useful to search for new concepts. In order to avoid the well-known short-term and long-term postoperative complications a pressure-controlled microstent with antiproliferative surface modifications was developed. Additionally, the functionality of such a microstent should be investigated using an animal glaucoma model. This paper describes the concept of a microstent which drains aquous humour from the anterior chamber into the suprachoroidal space. In addition, the glaucoma models described in the literature are discussed. Unfortunately, none of the methods could be reproduced permanently. First results show a correct implantation of a coated microstent with valve where the anti-proliferative effect could be demonstrated histologically. The promising results should lead to further investigations and the final goal will be the testing of the stent in the human eye. PMID:23887742

Allemann, R; Stachs, O; Falke, K; Schmidt, W; Siewert, S; Sternberg, K; Chichkov, B; Wree, A; Schmitz, K-P; Guthoff, R F

2013-08-01

90

Impact of 13-valent pneumococcal conjugate vaccine (PCV13) in a pandemic similar to the 2009 H1N1 in the United States  

PubMed Central

Background High rates of bacterial coinfection in autopsy data from the 2009 H1N1 influenza (“flu”) pandemic suggest synergies between flu and pneumococcal disease (PD) during pandemic conditions, and highlight the importance of interventions like the 13-valent pneumococcal conjugate vaccine (PCV13) that may mitigate the impact of a pandemic. Methods We used a decision-analytic model, estimated from published sources, to assess the impact of pediatric vaccination with PCV13 versus the 7-valent vaccine (PCV7) on PD incidence and mortality in a normal flu season (10% flu incidence) and in a pandemic similar to 2009-2010 H1N1 (20% flu incidence, mild virulence, high impact in children). Both direct and indirect (herd) effects against PD were considered. Effectiveness of PCV13 was extrapolated from observed PCV7 data, using assumptions of serotype prevalence and PCV13 protection against the 6 serotypes not in PCV7. To simulate 2009–2010 H1N1, autopsy data were used to estimate the overall proportion of flu deaths with bacterial coinfections. By assuming that increased risk of death during the pandemic occurred among those with comorbidity (using obesity as proxy) and bacterial coinfections primarily due to S. pneumoniae or S. aureus, we estimated the proportion co-infected among all (fatal and non-fatal) flu cases (7.6% co-infected with any organism; 2.2% with S. pneumoniae). PD incidence, mortality, and total healthcare costs were evaluated over a 1-year horizon. Results In a normal flu season, compared to PCV7, PCV13 is expected to prevent an additional 13,400 invasive PD (IPD) cases, 399,000 pneumonia cases, and 2,900 deaths, leading to cost savings of $472 M. In a pandemic similar to 2009–2010 H1N1, PCV13 would prevent 22,800 IPD cases, 872,000 pneumonia cases, and 3,700 deaths, resulting in cost savings of $1.0 B compared to PCV7. Conclusions In a flu pandemic similar to the 2009–2010 H1N1, protection against the 6 additional serotypes in PCV13 would likely be effective in preventing pandemic-related PD cases, mortality, and associated costs.

2013-01-01

91

Non-invasive ventilation  

Microsoft Academic Search

Non-invasive ventilation (NIV) refers to the delivery of mechanical ventilation to the lungs using techniques that do not\\u000a require an endotracheal airway. Essentially, there are two modalities: continuous positive airway pressure (CPAP) and pressure\\u000a support ventilation (NIPSV). In acute pulmonary edema (APE) both modalities have shown a faster improvement in gas exchange\\u000a and physiologic parameters with respect to conventional oxygen

Josep Masip

2007-01-01

92

Dual expression system for assembling phage lambda display particle (LDP) vaccine to porcine Circovirus 2 (PCV2)  

Microsoft Academic Search

The bacteriophage lambda small capsid protein D forms trimers on the phage head. D-fusion polypeptides can be expressed from plasmids in E. coli and remain soluble without aggregation. We report a dual expression system for the display of four immunodominant regions of porcine Circovirus 2 (PCV2) capsid protein (CAP) as D-CAP fusions on lambda display particles (LDP). The LDP-D-CAP preparation

Sidney Hayes; Lakshman N. A. Gamage; Connie Hayes

2010-01-01

93

Poor Long-Term Blood Pressure Control after Intracerebral Hemorrhage  

PubMed Central

Background and Purpose Hypertension is the most important risk factor associated with intracerebral hemorrhage (ICH). We explored racial differences in blood pressure (BP) control after ICH and assessed predictors of BP control at presentation, 30 days, and 1 year in a prospective cohort study. Methods Subjects with spontaneous ICH were identified from the DiffErenCes in the Imaging of Primary Hemorrhage based on Ethnicity or Race (DECIPHER) Project. Blood pressure was compared by race at each time point. Multivariable linear regression was used to determine predictors of presenting mean arterial pressure (MAP), and longitudinal linear regression was used to assess predictors of MAP at follow-up. Results A total of 162 patients were included (mean age 59, 53% male, 77% black). MAP at presentation was 9.6 mmHg higher in blacks than whites despite adjustment for confounders (p=0.065). Fewer than 20% of patients had normal blood pressure (<120/80 mmHg) at 30 days or 1 year. While there was no difference at 30 days (p=0.331), blacks were more likely than whites to have Stage I/II hypertension at one year (p=0.036). Factors associated with lower MAP at follow-up in multivariable analysis were being married at baseline (p=0.032) and living in a facility (versus personal residence) at the time of BP measurement (p=0.023). Conclusions Long-term blood pressure control is inadequate in patients following ICH, particularly in blacks. Further studies are needed to understand the role of social support and barriers to control to identify optimal approaches to improve blood pressure in this high-risk population.

Zahuranec, Darin B.; Wing, Jeffrey J.; Edwards, Dorothy F.; Menon, Ravi S.; Fernandez, Stephen J.; Burgess, Richard E.; Sobotka, Ian A.; German, Laura; Trouth, Anna J.; Shara, Nawar M.; Gibbons, M. Chris; Boden-Albala, Bernadette; Kidwell, Chelsea S.

2012-01-01

94

Pulmonary ventilation/perfusion scan  

MedlinePLUS

V/Q scan; Ventilation/perfusion scan; Lung ventilation/perfusion scan ... A pulmonary ventilation/perfusion scan is actually two tests. They may be done separately or together. During the perfusion ...

95

Efficacy of a reformulated inactivated chimeric PCV1-2 vaccine based on clinical, virological, pathological and immunological examination under field conditions.  

PubMed

Inactivated chimeric porcine circovirus (PCV) 1-2 vaccine was initially taken off the market due to concerns that the vaccine virus was not killed and thus further replicated and spread in the pig population. In August 2011, a reformulated inactivated chimeric PCV1-2 vaccine re-entered the market. The efficacy of the reformulated inactivated chimeric PCV1-2 vaccine was evaluated under field conditions for registration as recommended by the Republic of Korea's Animal, Plant & Fisheries Quarantine & Inspection Agency. Three farms were selected based on their history of postweaning multisystemic wasting syndrome (PMWS). On each farm, a total of 50 3-week-old pigs were randomly allocated to one of two treatment groups: (i) vaccinated at 3 weeks of age and (ii) non-vaccinated. Clinical examination indicated that vaccinated animals displayed an improved average daily weight gain (672.2g/day vs. 625g/day; difference of +47.3g/day; P<0.05) and a reduced time to market (177 days vs. 183 days; difference of -6 days; P<0.05). Virological examination indicated that vaccinated animals displayed a reduced PCV2 load in the blood and nasal swabs compared to non-vaccinated animals. Pathological examination indicated that vaccination of pigs against PCV2 effectively reduced the number of PMWS-associated microscopic lesions and the PCV2 load in lymphoid tissues compared to non-vaccinated animals in the 3 herds. Immunological examination indicated that vaccinated animals induced PCV2-specific neutralizing antibodies (NA) and interferon-?-secreting cells (IFN-?-SCs). A reduction in the PCV2 load in the blood coincided with the appearance of both PCV2-specific NA and IFN-?-SCs in the vaccinated animals. The number of CD4(+) cells was decreased in non-vaccinated animals compared to vaccinated animals. The reformulated inactivated chimeric PCV1-2 vaccine seems to be very effective in controlling PCV2 infection based on clinical, virological, pathological, and immunological evaluations under field conditions. PMID:22963801

Seo, Hwi Won; Han, Kiwon; Oh, Yeonsu; Park, Changhoon; Chae, Chanhee

2012-09-07

96

Multifamily Ventilation Retrofit Strategies  

SciTech Connect

In multifamily buildings, central ventilation systems often have poor performance, overventilating some portions of the building (causing excess energy use), while simultaneously underventilating other portions (causing diminished indoor air quality). BSC and Innova Services Corporation performed a series of field tests at a mid-rise test building undergoing a major energy audit and retrofit, which included ventilation system upgrades.

Ueno, K.; Lstiburek, J.; Bergey, D.

2012-12-01

97

Thailand ventilation comfort chart  

Microsoft Academic Search

The paper presents a ventilation comfort chart that has been developed under Thailand climate and using Thai volunteers. 183 male and 105 female college-age subjects were exposed to different thermal conditions in order to investigate the effect of air velocity on thermal comfort in ventilated “non-conditioned” spaces. To this end, commercial electric fans were used to control the air velocity

Joseph Khedari; Nuparb Yamtraipat; Naris Pratintong; Jongjit Hirunlabh

2000-01-01

98

A meta-analysis comparing the effect of PCV2 vaccines on average daily weight gain and mortality rate in pigs from weaning to slaughter  

Microsoft Academic Search

The aim of this investigation was, through a meta-analysis, to review the published literature concerning the effect of PCV2 vaccination on the average daily weight gain (ADG) and on the mortality rate in pigs from weaning to slaughter.The review was restricted to studies investigating the effect of vaccines against PCV2 published from 2006 to 2008, identified using computerised literature databases.

Charlotte Sonne Kristensen; Niels Peter Baadsgaard; Nils Toft

2011-01-01

99

Epidemiology and risk factors for Staphylococcus aureus colonization in children in the post-PCV7 era  

PubMed Central

Background The incidence of community-associated methicillin-resistant Staphylococcus aureus (MRSA) has risen dramatically in the U.S., particularly among children. Although Streptococcus pneumoniae colonization has been inversely associated with S. aureus colonization in unvaccinated children, this and other risk factors for S. aureus carriage have not been assessed following widespread use of the heptavalent pneumococcal conjugate vaccine (PCV7). Our objectives were to (1) determine the prevalence of S. aureus and MRSA colonization in young children in the context of widespread use of PCV7; and (2) examine risk factors for S. aureus colonization in the post-PCV7 era, including the absence of vaccine-type S. pneumoniae colonization. Methods Swabs of the anterior nares (S. aureus) were obtained from children enrolled in an ongoing study of nasopharyngeal pneumococcal colonization of healthy children in 8 Massachusetts communities. Children 3 months to <7 years of age seen for well child or sick visits in primary care offices from 11/03–4/04 and 10/06–4/07 were enrolled. S. aureus was identified and antibiotic susceptibility testing was performed. Epidemiologic risk factors for S. aureus colonization were collected from parent surveys and chart reviews, along with data on pneumococcal colonization. Multivariate mixed model analyses were performed to identify factors associated with S. aureus colonization. Results Among 1,968 children, the mean age (SD) was 2.7 (1.8) years, 32% received an antibiotic in the past 2 months, 2% were colonized with PCV7 strains and 24% were colonized with non-PCV7 strains. The prevalence of S. aureus colonization remained stable between 2003–04 and 2006–07 (14.6% vs. 14.1%), while MRSA colonization remained low (0.2% vs. 0.9%, p = 0.09). Although absence of pneumococcal colonization was not significantly associated with S. aureus colonization, age (6–11 mo vs. ?5 yrs, OR 0.39 [95% CI 0.24–0.64]; 1–1.99 yrs vs. ?5 yrs, OR 0.35 [0.23–0.54]; 2–2.99 yrs vs. ?5 yrs, OR 0.45 [0.28–0.73]; 3–3.99 yrs vs. ?5 yrs, OR 0.53 [0.33–0.86]) and recent antibiotic use were significant predictors in multivariate models. Conclusion In Massachusetts, S. aureus and MRSA colonization remained stable from 2003–04 to 2006–07 among children <7 years despite widespread use of pneumococcal conjugate vaccine. S. aureus nasal colonization varies by age and is inversely correlated with recent antibiotic use.

2009-01-01

100

Realtime mine ventilation simulation  

SciTech Connect

This paper describes the development of a Windows based, interactive mine ventilation simulation software program at the Waste Isolation Pilot Plant (WIPP). To enhance the operation of the underground ventilation system, Westinghouse Electric Corporation developed the program called WIPPVENT. While WIPPVENT includes most of the functions of the commercially available simulation program VNETPC and uses the same subroutine to calculate airflow distributions, the user interface has been completely rewritten as a Windows application with screen graphics. WIPPVENT is designed to interact with WIPP ventilation monitoring systems through the sitewise Central monitoring System. Data can be continuously collected from the Underground Ventilation Remote Monitoring and Control System (e.g., air quantity and differential pressure) and the Mine Weather Stations (psychrometric data). Furthermore, WIPPVENT incorporates regulator characteristic curves specific to the site. The program utilizes this data to create and continuously update a REAL-TIME ventilation model. This paper discusses the design, key features, and interactive capabilities of WIPPVENT.

McDaniel, K.H. [Westinghouse Electric Corp., Carlsbad, NM (United States). Waste Isolation Div.; Wallace, K.G. Jr. [Mine Ventilation Services, Inc., Fresno, CA (United States)

1997-04-01

101

Conventional mechanical ventilation.  

PubMed

Mechanical ventilation has become a very common and well-accepted practice in modern intensive care units. The use of the mechanical ventilator has progressed from being a support system during surgery and for acutely ill patients to being used in both moderate and long-term life support in patients with inadequate ventilation. The sophistication of modern ventilators and the ability of trained respiratory therapists and nursing personnel have permitted this technology to explode. This is occurring at a time when there are still many controversies about the relative benefits and modes of action of conventional ventilation. As newer techniques are developed, it is mandatory that the application of these techniques be tempered with controlled clinical trials, documenting their effectiveness. The beneficial effects of new modalities must be documented as mechanical ventilation expands from use in the intensive care unit to use in standard medical wards and the patient's home. In these latter two settings, the vigilance of an intensive care unit is absent and the simplest method will be preferable. The requirement to demonstrate efficacy of new techniques with adequate studies is especially necessary now as the economics of health delivery have come under increasing scrutiny. Even more important than new technologies may be the efficacy of prolonged mechanical ventilation. A recent study by Spicher and White evaluated the outcome in 250 patients ventilated for 10 days or more at the Hershey Medical Center (Pennsylvania State University). The mortality, morbidity, and disability in patients in this study population requiring prolonged ventilation were extremely high. As these studies have pointed out, further evaluations of predictors of meaningful survival are necessary to avoid unnecessary human suffering and to best use limited resources. PMID:3280230

Grum, C M; Chauncey, J B

1988-03-01

102

Natural Ventilation of Parral Greenhouses  

Microsoft Academic Search

A study was carried out at the Experimental Station Las Palmerillas of Cajamar to characterise the natural ventilation of the parral greenhouse. An 882m2, five span, polyethylene film covered parral greenhouse was fitted with either a rolling or a flap ventilator attached to one side of each ridge and rolling ventilators in two 38m sidewalls. Ventilation rates for different configurations

J. Pérez Parra; E. Baeza; J. I. Montero; B. J. Bailey

2004-01-01

103

Why We Ventilate  

SciTech Connect

It is widely accepted that ventilation is critical for providing good indoor air quality (IAQ) in homes. However, the definition of"good" IAQ, and the most effective, energy efficient methods for delivering it are still matters of research and debate. This paper presents the results of work done at the Lawrence Berkeley National Lab to identify the air pollutants that drive the need for ventilation as part of a larger effort to develop a health-based ventilation standard. First, we present results of a hazard analysis that identified the pollutants that most commonly reach concentrations in homes that exceed health-based standards or guidelines for chronic or acute exposures. Second, we present results of an impact assessment that identified the air pollutants that cause the most harm to the U.S. population from chronic inhalation in residences. Lastly, we describe the implications of our findings for developing effective ventilation standards.

Logue, Jennifer M.; Sherman, Max H.; Price, Phil N.; Singer, Brett C.

2011-09-01

104

What Is a Ventilator?  

MedlinePLUS

... hospitals. Ventilators: Get oxygen into the lungs. Remove carbon dioxide from the body. (Carbon dioxide is a waste gas that can be ... NHLBI updates Health Topics articles on a biennial cycle based on a thorough review of research findings ...

105

Pulmonary ventilation during hemodialysis.  

PubMed

During hemodialysis a decrease in pulmonary ventilation has been reported. The elimination of CO2 across the dialyzer has been suggested as the cause of the pulmonary hypoventilation. Our purpose was to analyze the factors that could have influenced the pulmonary ventilation of 7 patients with chronic renal failure during hemodialysis, performed against an acetate dialysate with constant addition of CO2, bubbling into the dialysis bath. In spite of the large volume of CO2 mainly as bicarbonate, eliminated across the dialyzer there was no significant decrease of ventilation. The values of pH in the venous line were extremely low and the values of PvCO2 were artificially maintained around 35.0 mm Hg. Thus, the total CO2 delivered to the lungs, but mainly the levels of pH and PCO2 in the venous line play an important role in the control of pulmonary ventilation of these patients. PMID:6817152

Romaldini, H; Stabile, C; Faro, S; Lopes Dos Santos, M; Ramos, O L; Ratto, O R

1982-01-01

106

Impact of routine PCV7 (Prevenar) vaccination of infants on the clinical and economic burden of pneumococcal disease in Malaysia  

PubMed Central

Background Pneumococcal disease is the leading cause of vaccine-preventable death in children younger than 5 years of age worldwide. The World Health Organization recommends pneumococcal conjugate vaccine as a priority for inclusion into national childhood immunization programmes. Pneumococcal vaccine has yet to be included as part of the national vaccination programme in Malaysia although it has been available in the country since 2005. This study sought to estimate the disease burden of pneumococcal disease in Malaysia and to assess the cost effectiveness of routine infant vaccination with PCV7. Methods A decision model was adapted taking into consideration prevalence, disease burden, treatment costs and outcomes for pneumococcal disease severe enough to result in a hospital admission. Disease burden were estimated from the medical records of 6 hospitals. Where local data was unavailable, model inputs were obtained from international and regional studies and from focus group discussions. The model incorporated the effects of herd protection on the unvaccinated adult population. Results At current vaccine prices, PCV7 vaccination of 90% of a hypothetical 550,000 birth cohort would incur costs of RM 439.6 million (US$128 million). Over a 10 year time horizon, vaccination would reduce episodes of pneumococcal hospitalisation by 9,585 cases to 73,845 hospitalisations with cost savings of RM 37.5 million (US$10.9 million) to the health system with 11,422.5 life years saved at a cost effectiveness ratio of RM 35,196 (US$10,261) per life year gained. Conclusions PCV7 vaccination of infants is expected to be cost-effective for Malaysia with an incremental cost per life year gained of RM 35,196 (US$10,261). This is well below the WHO's threshold for cost effectiveness of public health interventions in Malaysia of RM 71,761 (US$20,922).

2011-01-01

107

Conventional mechanical ventilation  

PubMed Central

The provision of mechanical ventilation for the support of infants and children with respiratory failure or insufficiency is one of the most common techniques that are performed in the Pediatric Intensive Care Unit (PICU). Despite its widespread application in the PICUs of the 21st century, before the 1930s, respiratory failure was uniformly fatal due to the lack of equipment and techniques for airway management and ventilatory support. The operating rooms of the 1950s and 1960s provided the arena for the development of the manual skills and the refinement of the equipment needed for airway management, which subsequently led to the more widespread use of endotracheal intubation thereby ushering in the era of positive pressure ventilation. Although there seems to be an ever increasing complexity in the techniques of mechanical ventilation, its successful use in the PICU should be guided by the basic principles of gas exchange and the physiology of respiratory function. With an understanding of these key concepts and the use of basic concepts of mechanical ventilation, this technique can be successfully applied in both the PICU and the operating room. This article reviews the basic physiology of gas exchange, principles of pulmonary physiology, and the concepts of mechanical ventilation to provide an overview of the knowledge required for the provision of conventional mechanical ventilation in various clinical arenas.

Tobias, Joseph D.

2010-01-01

108

Ventilator discontinuation protocols.  

PubMed

Mechanical ventilation is a life-saving supportive therapy, but it can also cause lung injury, diaphragmatic dysfunction, and lung infection. Ventilator liberation should be attempted as soon as clinically indicated, to minimize morbidity and mortality. The most effective method of liberation follows a systematic approach that includes a daily assessment of weaning readiness, in conjunction with interruption of sedation infusions and spontaneous breathing trials. Protocols and checklists are decision support tools that help ensure consistent application of key elements of evidence-based practice. A majority of studies of weaning protocols applied by non-physician healthcare providers suggest faster weaning and shorter duration of ventilation and ICU stay, and some suggest reduced failed extubation and ventilator-associated pneumonia rates. Checklists can be used to reinforce application of the protocol, or possibly in lieu of one, particularly in environments where the caregiver-to-patient ratio is high and clinicians are well versed in and dedicated to applying evidence-based care. There is support for integrating best-evidence rules for weaning into the mechanical ventilator so that a substantial portion of the weaning process can be automated, which may be most effective in environments with low caregiver-to-patient ratios or those in which it is challenging to consistently apply evidence-based care. This paper reviews evidence for ventilator liberation protocols and discusses issues of implementation and ongoing monitoring. PMID:23013902

Haas, Carl F; Loik, Paul S

2012-10-01

109

Ventilation strategies for different climates  

SciTech Connect

Until recently, residential ventilation in the United States has been provided by infiltration. In this report we compare natural ventilation (ventilation by infiltration) with several mechanical ventilation strategies and examine the overall energy consumption associated with these strategies in different climatic regions in the US. The strategies examined are: natural ventilation, balanced ventilation with an air-to-air heat exchanger, exhaust ventilation without heat recovery, and exhaust ventilation with heat recovery via a heat pump. Two strategies for utilizing the heat pump output for domestic hot water are examined. One heat pump strategy employs exhaust fan reversal to provide space cooling whenever possible during the summer months. A modified TRNSYS residential load model incorporating the LBL infiltration model, an algorithm to calculate effective ventilation, and a modified TRNSYS domestic hot water model are used to simulate the energy consumption associated with each strategy. The domestic hot water model is used to determine the useful heat supplied by an exhaust ventilation heat pump as a function of daily hot water demand. The simulations indicate that the choice of ventilation strategy can have a significant impact on energy consumption. They show that total end-use energy consumption can be reduced as much by mechanical ventilation as by superinsulation of a house. The comparisons also show that for the same effective ventilation rate, houses with mechanical ventilation systems (especially those with exhaust fans) have been indoor air quality than those that rely on natural ventilation. 19 refs.

Feustel, H.E.; Modera, M.P.; Rosenfeld, A.H.

1987-03-01

110

SEVENTH INTERIM STATUS REPORT: MODEL 9975 PCV O-RING FIXTURE LONG-TERM LEAK PERFORMANCE  

SciTech Connect

A series of experiments to monitor the aging performance of Viton® GLT O-rings used in the Model 9975 package has been ongoing since 2004 at the Savannah River National Laboratory. Seventy tests using mock-ups of 9975 Primary Containment Vessels (PCVs) were assembled and heated to temperatures ranging from 200 to 450 ºF. They were leak-tested initially and have been tested periodically to determine if they meet the criterion of leak-tightness defined in ANSI standard N14.5-97. Fourteen additional tests were initiated in 2008 with GLT-S O-rings heated to temperatures ranging from 200 to 400 ºF. High temperature aging continues for 23 GLT O-ring fixtures at 200 – 270 ºF. Room temperature leak test failures have been experienced in all of the GLT O-ring fixtures aging at 350 ºF and higher temperatures, and in 8 fixtures aging at 300 ºF. The remaining GLT O-ring fixtures aging at 300 ºF have been retired from testing following more than 5 years at temperature without failure. No failures have yet been observed in GLT O-ring fixtures aging at 200 ºF for 54-72 months, which is still bounding to O-ring temperatures during storage in K-Area Complex (KAC). Based on expectations that the fixtures aging at 200 ºF will remain leak-tight for a significant period yet to come, 2 additional fixtures began aging in 2011 at an intermediate temperature of 270 ºF, with hopes that they may reach a failure condition before the 200 ºF fixtures. High temperature aging continues for 6 GLT-S O-ring fixtures at 200 – 300 ºF. Room temperature leak test failures have been experienced in all 8 of the GLT-S O-ring fixtures aging at 350 and 400 ºF. No failures have yet been observed in GLT-S O-ring fixtures aging at 200 - 300 ºF for 30 - 36 months. For O-ring fixtures that have failed the room temperature leak test and been disassembled, the O-rings displayed a compression set ranging from 51 – 96%. This is greater than seen to date for any packages inspected during KAC field surveillance (24% average). For GLT O-rings, separate service life estimates have been made based on the O-ring fixture leak test data and based on compression stress relaxation (CSR) data. These two predictive models show reasonable agreement at higher temperatures (350 – 400 ºF). However, at 300 ºF, the room temperature leak test failures to date experienced longer aging times than predicted by the CSRbased model. This suggests that extrapolations of the CSR model predictions to temperatures below 300 ºF will provide a conservative prediction of service life relative to the leak rate criterion. Leak test failure data at lower temperatures are needed to verify this apparent trend. Insufficient failure data exist currently to perform a similar comparison for GLT-S O-rings. Aging and periodic leak testing will continue for the remaining PCV O-ring fixtures.

Daugherty, W.

2012-08-30

111

Ventilator associated pneumonia  

PubMed Central

Hospital acquired or nosocomial infections continue to be an important cause of morbidity and mortality. The critically ill patient is at particular risk of developing intensive care unit acquired infection, with the lungs being especially vulnerable. Nosocomial bacterial pneumonia occurring after two days of mechanical ventilation is referred to as ventilator associated pneumonia, and is the most common nosocomial infection seen in the intensive care unit. Intubation of the trachea and mechanical ventilation is associated with a 7?fold to 21?fold increase in the incidence of pneumonia and up to 28% of patients receiving mechanical ventilation will develop this complication. Its development is associated with an attributable increase in morbidity and mortality. The establishment of an accurate diagnosis of ventilator associated pneumonia remains problematic and as yet there is still no accepted “gold standard” for diagnosis. The responsible pathogens vary according to case mix, local resistance patterns, and methodology of sampling. However, there is general agreement that rapid initiation of appropriate antimicrobial therapy improves outcome.

Hunter, J D

2006-01-01

112

Invasive ventilation modes in children: a systematic review and meta-analysis  

PubMed Central

Introduction The purpose of the present study was to critically review the existing body of evidence on ventilation modes for infants and children up to the age of 18 years. Methods The PubMed and EMBASE databases were searched using the search terms 'artificial respiration', 'instrumentation', 'device', 'devices', 'mode', and 'modes'. The review included only studies comparing two ventilation modes in a randomized controlled study and reporting one of the following outcome measures: length of ventilation (LOV), oxygenation, mortality, chronic lung disease and weaning. We quantitatively pooled the results of trials where suitable. Results Five trials met the inclusion criteria. They addressed six different ventilation modes in 421 children: high-frequency oscillation (HFO), pressure control (PC), pressure support (PS), volume support (VS), volume diffusive respirator (VDR) and biphasic positive airway pressure. Overall there were no significant differences in LOV and mortality or survival rate associated with the different ventilation modes. Two trials compared HFO versus conventional ventilation. In the pooled analysis, the mortality rate did not differ between these modes (odds ratio = 0.83, 95% confidence interval = 0.30 to 1.91). High-frequency ventilation (HFO and VDR) was associated with a better oxygenation after 72 hours than was conventional ventilation. One study found a significantly higher PaO2/FiO2 ratio with the use of VDR versus PC ventilation in children with burns. Weaning was studied in 182 children assigned to either a PS protocol, a VS protocol or no protocol. Most children could be weaned within 2 days and the weaning time did not significantly differ between the groups. Conclusions The literature provides scarce data for the best ventilation mode in critically ill children beyond the newborn period. There is no evidence, however, that high-frequency ventilation reduced mortality and LOV. Longer-term outcome measures such as pulmonary function, neurocognitive development, and cost-effectiveness should be considered in future studies.

2011-01-01

113

Ventilation technologies scoping study  

SciTech Connect

This document presents the findings of a scoping study commissioned by the Public Interest Energy Research (PIER) program of the California Energy Commission to determine what research is necessary to develop new residential ventilation requirements for California. This study is one of three companion efforts needed to complete the job of determining the needs of California, determining residential ventilation requirements, and determining appropriate ventilation technologies to meet these needs and requirements in an energy efficient manner. Rather than providing research results, this scoping study identifies important research questions along with the level of effort necessary to address these questions and the costs, risks, and benefits of pursuing alternative research questions. In approaching these questions and level of effort, feasibility and timing were important considerations. The Commission has specified Summer 2005 as the latest date for completing this research in time to update the 2008 version of California's Energy Code (Title 24).

Walker, Iain S.; Sherman, Max H.

2003-09-30

114

Overdistension in ventilated children  

PubMed Central

Ventilating patients with acute respiratory failure according to standardized recommendations can lead to varying volume–pressure (V-P) relationships and overdistension. Young children may be more susceptible than adults to overdistension, and individual evaluation of the effects of ventilator settings is therefore required. Three studies have applied indices for the detection of overdistension to dynamic V-P curves in ventilated children. Two of those studies compared these indices to those obtained using a reference technique ([quasi]-static V-P curves), and suggested that the c coefficient of a second order polynomial equation (SOPE) and the ratio of the volume-dependent elastance to total dynamic elastance (%E2) were suitable indices for estimating overdistension.

Neve, Veronique; Leclerc, Francis; Roque, Eric Dumas de la; Leteurtre, Stephane; Riou, Yvon

2001-01-01

115

Meeting Residential Ventilation Standards Through Dynamic Control of Ventilation Systems  

SciTech Connect

Existing ventilation standards, including American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE) Standard 62.2, specify continuous operation of a defined mechanical ventilation system to provide minimum ventilation, with time-based intermittent operation as an option. This requirement ignores several factors and concerns including: other equipment such as household exhaust fans that might incidentally provide ventilation, negative impacts of ventilation when outdoor pollutant levels are high, the importance of minimizing energy use particularly during times of peak electricity demand, and how the energy used to condition air as part of ventilation system operation changes with outdoor conditions. Dynamic control of ventilation systems can provide ventilation equivalent to or better than what is required by standards while minimizing energy costs and can also add value by shifting load during peak times and reducing intake of outdoor air contaminants. This article describes the logic that enables dynamic control of whole-house ventilation systems to meet the intent of ventilation standards and demonstrates the dynamic ventilation system control concept through simulations and field tests of the Residential Integrated Ventilation-Energy Controller (RIVEC).

Sherman, Max H.; Walker, Iain S.

2011-04-01

116

[Choice of optimal ventilation maintenance].  

PubMed

Twenty-nine angiosurgical patients with disordered ventilation-perfusion correlations were examined. Effects of CMV (controlled mechanical ventilation) + PEEP (positive end expiratory pressure) and IRV (inverse ratio of ventilation) on gas exchange and hemodynamics of the lungs were studied. Gas exchange improved in all patients, but sooner in the CMV + PEEP group. CI increase was more pronounced in the IRV group. PMID:12221881

Amerov, D B; Kazennov, V V; Likhvantsev, V V; Shishkin, M N; Morozova, M E

117

Ventilation effects on combustion products  

Microsoft Academic Search

The effects of fire ventilation on combustion products are expressed in terms of relationship between concentration of products and equivalence ratio, ?. For well-ventilated fires, ? < 1.0, where mostly heat and products of complete combustion (such as CO2 and water) are generated. For ventilation-controlled fires, ? > 1.0, where mostly products of incomplete combustion are generated with very high

A Tewarson

1996-01-01

118

Ventilation requirements for uranium mines  

Microsoft Academic Search

The planning and operation of ventilation network systems for uranium mines require special considerations since ventilation is the primary technique of controlling ambient concentrations of radon progeny. The major environmental challenge facing the ventilation engineer is the requirement to dilute radon progeny to below the Working Level Month per year of worker exposure required by law. The application of large

C. Gherghel; E. De Souza

119

Measure Guideline: Ventilation Cooling  

SciTech Connect

The purpose of this measure guideline on ventilation cooling is to provide information on a cost-effective solution for reducing cooling system energy and demand in homes located in hot-dry and cold-dry climates. This guideline provides a prescriptive approach that outlines qualification criteria, selection considerations, and design and installation procedures.

Springer, D.; Dakin, B.; German, A.

2012-04-01

120

Positive pressure mechanical ventilation  

Microsoft Academic Search

Andreas Wesele Vesalius documented the first known attempt at assisted ventilation in 1555. He observed, ''An opening must be attempted in the trunk of the trachea, into which a tube of reed or cane should be put; you will then blow into this, so that the lung may rise again and the animal take in air.'' Though primitive, this formed

Bhargavi Gali; Deepi G. Goyal

2003-01-01

121

Laboratory Ventilation and Safety.  

ERIC Educational Resources Information Center

|In order to meet the needs of both safety and economy, laboratory ventilation systems must effectively remove air-borne toxic and flammable materials and at the same time exhaust a minimum volume of air. Laboratory hoods are the most commonly used means of removing gases, dusts, mists, vapors, and fumed from laboratory operations. To be…

Steere, Norman V.

1965-01-01

122

Laboratory Ventilation and Safety.  

ERIC Educational Resources Information Center

In order to meet the needs of both safety and economy, laboratory ventilation systems must effectively remove air-borne toxic and flammable materials and at the same time exhaust a minimum volume of air. Laboratory hoods are the most commonly used means of removing gases, dusts, mists, vapors, and fumed from laboratory operations. To be effective,…

Steere, Norman V.

1965-01-01

123

Ventilator-associated pneumonia  

Microsoft Academic Search

Ventilator-associated pneumonia is the most common nosocomial infection. Mortality rates, morbidity, and costs are all increased in the patient with VAP, and every measure should thus be taken to prevent its development. There are several clearly defined risk factors for VAP, and awareness of these can facilitate early diagnosis and hence treatment. In this article, we discuss the risk factors,

J.-L Vincent

2004-01-01

124

Supercavitation Ventilation Control System.  

National Technical Information Service (NTIS)

A supercavitation ventilation control system is disclosed and includes a vehicle body having a fore end and an aft end. A cavitator is fit to the fore end of the vehicle body, the cavitator generating a gas cavity around the vehicle body. A cavity control...

R. Kuklinski

2002-01-01

125

RESIDENTIAL VENTILATION STUDY  

EPA Science Inventory

This project evaluated the effectiveness, first costs and operational costs of various types of residential ventilation systems in three different climates in the U.S. The Agency, through its Energy Star Program, recommends that builders construct homes that are energy efficient ...

126

Public health and economic impact of vaccination with 7-valent pneumococcal vaccine (PCV7) in the context of the annual influenza epidemic and a severe influenza pandemic  

PubMed Central

Background Influenza pandemic outbreaks occurred in the US in 1918, 1957, and 1968. Historical evidence suggests that the majority of influenza-related deaths during the 1918 US pandemic were attributable to bacterial pneumococcal infections. The 2009 novel influenza A (H1N1) outbreak highlights the importance of interventions that may mitigate the impact of a pandemic. Methods A decision-analytic model was constructed to evaluate the impact of 7-valent pneumococcal conjugate vaccine (PCV7) on pneumococcal disease incidence and mortality during a typical influenza season (13/100) and a severe influenza pandemic (30/100). Outcomes were compared for current PCV7 vaccination practices vs. no vaccination. The model was estimated using published sources and includes indirect (herd) protection of non-vaccinated persons. Results The model predicts that PCV7 vaccination in the US is cost saving for a normal influenza season, reducing pneumococcal-related costs by $1.6 billion. In a severe influenza pandemic, vaccination would save $7.3 billion in costs and prevent 512,000 cases of IPD, 719,000 cases of pneumonia, 62,000 IPD deaths, and 47,000 pneumonia deaths; 84% of deaths are prevented due to indirect (herd) protection in the unvaccinated. Conclusions PCV7 vaccination is highly effective and cost saving in both normal and severe pandemic influenza seasons. Current infant vaccination practices may prevent >1 million pneumococcal-related deaths in a severe influenza pandemic, primarily due to herd protection.

2010-01-01

127

Noisy Ventilation Improves Lung Function  

NASA Astrophysics Data System (ADS)

It has been shown that mechanical ventilation in the setting of acute lung injury may propagate additional injury within the lung and numerous studies have been carried out to determine the optimal method of minimizing ventilator induced lung injury while still maintaining life-sustaining gas exchange. We have found that noise added to tidal volume and frequency, called noisy ventilation, during mechanical ventilation improves both lung mechanics and oxygenation in a rodent model of acute lung injury. Additionally, the standard deviation of the noise appears to be directly related to the magnitude of improvements seen with this ventilation modality in a manner similar to stochastic resonance. Furthermore, healthy guinea pigs that underwent with noisy ventilation exhibited increased surfactant content and reduced plasma proteins than their conventionally ventilated counterparts within the alveolar space of the lung. This suggests that not only did noisy ventilation induce endogenous surfactant release, but also served to reduce ventilator induced lung injury in this animal model. In conclusion, noisy ventilation improves blood oxygenation during acute lung injury and also serves to enhance lung function and reduce ventilator induced lung injury in healthy lungs.

Suki, Béla; Arold, Stephen P.; Alencar, Adriano; Lutchen, Kenneth R.; Ingenito, Edward P.

2003-05-01

128

The Association between Medication Adherence and Treatment Intensification with Blood Pressure Control in Resistant Hypertension  

PubMed Central

Patients with resistant hypertension are at risk for poor outcomes. Medication adherence and intensification improve blood pressure control; however, little is known about these processes or their association with outcomes in resistant hypertension. This retrospective study included patients from 2002-2006 with incident hypertension from two health systems who developed resistant hypertension, or uncontrolled blood pressure despite adherence to ?3 antihypertensive medications. Patterns of hypertension treatment, medication adherence (percentage of days covered) and treatment intensification (increase in medication class or dose) were described in the year after resistant hypertension identification. Then, the association between medication adherence and intensification with 1-year blood pressure control was assessed controlling for patient characteristics. Of the 3,550 patients with resistant hypertension, 49% were male and mean age 60. One year after resistance hypertension determination, fewer patients were taking diuretics (77.7% vs. 92.2%, p<0.01), beta blockers (71.2% vs. 79.4%, p<0.01) and ACE/ARB (64.8% vs. 70.1%, p<0.01) compared to baseline. Rates of blood pressure control improved over 1-year (22% vs. 55%, p=<0.01). During this year, adherence was not associated with 1-year blood pressure control (adjusted OR 1.18, 0.94-1.47). Treatment was intensified in 21.6% of visits with elevated blood pressure. Increasing treatment intensity was associated with 1-year blood pressure control (adjusted OR 1.64; 95% CI 1.58-1.71). In this cohort of patients with resistant hypertension, treatment intensification but not medication adherence was significantly associated with 1-year blood pressure control. These findings highlight the need to investigate why patients with uncontrolled blood pressure do not receive treatment intensification.

Daugherty, Stacie L.; Powers, J. David; Magid, David J.; Masoudi, Frederick A.; Margolis, Karen L.; O'Connor, Patrick J; Schmittdiel, Julie; Ho, P. Michael

2012-01-01

129

ASHRAE and residential ventilation  

SciTech Connect

In the last quarter of a century, the western world has become increasingly aware of environmental threats to health and safety. During this period, people psychologically retreated away from outdoors hazards such as pesticides, smog, lead, oil spills, and dioxin to the seeming security of their homes. However, the indoor environment may not be healthier than the outdoor environment, as has become more apparent over the past few years with issues such as mold, formaldehyde, and sick-building syndrome. While the built human environment has changed substantially over the past 10,000 years, human biology has not; poor indoor air quality creates health risks and can be uncomfortable. The human race has found, over time, that it is essential to manage the indoor environments of their homes. ASHRAE has long been in the business of ventilation, but most of the focus of that effort has been in the area of commercial and institutional buildings. Residential ventilation was traditionally not a major concern because it was felt that, between operable windows and envelope leakage, people were getting enough outside air in their homes. In the quarter of a century since the first oil shock, houses have gotten much more energy efficient. At the same time, the kinds of materials and functions in houses changed in character in response to people's needs. People became more environmentally conscious and aware not only about the resources they were consuming but about the environment in which they lived. All of these factors contributed to an increasing level of public concern about residential indoor air quality and ventilation. Where once there was an easy feeling about the residential indoor environment, there is now a desire to define levels of acceptability and performance. Many institutions--both public and private--have interests in Indoor Air Quality (IAQ), but ASHRAE, as the professional society that has had ventilation as part of its mission for over 100 years, is the logical place to provide leadership. This leadership has been demonstrated most recently by the publication of the first nationally recognized standard on ventilation in homes, ASHRAE Standard 62.2-2003, which builds on work that has been part of ASHRAE for many years and will presumably continue. Homeowners and occupants, which includes virtually all of us, will benefit from the application of Standard 62.2 and use of the top ten list. This activity is exactly the kind of benefit to society that the founders of ASHRAE envisioned and is consistent with ASHRAE's mission and vision. ASHRAE members should be proud of their Society for taking leadership in residential ventilation.

Sherman, Max H.

2003-10-01

130

Pressure Controller  

NASA Astrophysics Data System (ADS)

EPIC is Electronic Pressure Indicating Controller produced by North American Manufacturing Company. It is a high-sensitivity device for improving combustion efficiency in industrial furnaces that interprets a signal from a pressure transducer on a furnace and regulates furnace pressure accordingly. A controller can provide savings of from five to 25 percent of an industrial user's annual furnace fuel bill.

1981-01-01

131

Changes in invasive pneumococcal disease serotypes in a regional area of Australia following three years of 7vPCV introduction  

PubMed Central

Background Invasive pneumococcal disease (IPD) is a serious bacterial disease. Vaccination can prevent disease for many of the current serotypes. The aim of this investigation was to describe the notification rates of IPD in a regional area of Australia, explore changes in rates since the introduction of the population vaccine programmes in 2005 and to describe changes in the distribution of serotypes in relation to the available vaccines after three years. Methods Annualized IPD notification rates were calculated for residents of a regional area in northern New South Wales. Rates were analysed according to serotypes covered by available vaccines. Changes in serotypes were compared for the periods 2002–2004 and 2008–2010. Results The annualized notification rate of IPD in all ages for the period 2002–2004 was 13.7 per 100 000 population, and 8.3 per 100 000 population for the period 2008–2010 (rate ratio [RR], 0.61, confidence interval [CI]: 0.51–0.72). The largest decline was observed in 7-valent pneumococcal conjugate vaccine (7vPCV) types across all age groups (RR, 0.17, CI: 0.12–0.24) and in the zero to four year age group (RR, 0.03, CI: 0.01–0.11). The six serotypes included in the new 13-valent pneumococcal conjugate vaccine, but not in the 7vPCV, accounted for 40.6% of IPD cases in the zero to four year age group during the period of 2008–2010. Discussion The introduction of 7vPCV significantly reduced the overall notification rate of IPD caused by the serotypes contained in this vaccine. This decline in IPD rates in children can be directly attributed to the use of 7vPCV, and in adults it is most likely an indirect effect of the 7vPCV programme in children.

Massey, Peter D; Islam, Fakhrul

2012-01-01

132

Non-Invasive Ventilation  

Microsoft Academic Search

Mechanical ventilation represents the most widely used supportive technique in the intensive care unit (ICU). Without mechanical\\u000a support for respiration, many patients would die within a few hours due to acute hypoxaemic and hypercapnic respiratory failure.\\u000a Several forms of external support for respiration have been described in the literature to assist the failing ventilatory\\u000a system. Chief among these is endotracheal

A. Peratoner; V. Antonaglia; U. Lucangelo

133

Increased duration of mechanical ventilation is associated with decreased diaphragmatic force: a prospective observational study  

PubMed Central

Introduction Respiratory muscle weakness is an important risk factor for delayed weaning. Animal data show that mechanical ventilation itself can cause atrophy and weakness of the diaphragm, called ventilator-induced diaphragmatic dysfunction (VIDD). Transdiaphragmatic pressure after magnetic stimulation (TwPdi BAMPS) allows evaluation of diaphragm strength. We aimed to evaluate the repeatability of TwPdi BAMPS in critically ill, mechanically ventilated patients and to describe the relation between TwPdi and the duration of mechanical ventilation. Methods This was a prospective observational study in critically ill and mechanically ventilated patients, admitted to the medical intensive care unit of a university hospital. Nineteen measurements were made in a total of 10 patients at various intervals after starting mechanical ventilation. In seven patients, measurements were made on two or more occasions, with a minimum interval of 24 hours. Results The TwPdi was 11.5 ± 3.9 cm H2O (mean ± SD), indicating severe respiratory muscle weakness. The between-occasion coefficient of variation of TwPdi was 9.7%, comparable with data from healthy volunteers. Increasing duration of mechanical ventilation was associated with a logarithmic decline in TwPdi (R = 0.69; P = 0.038). This association was also found for cumulative time on pressure control (R = 0.71; P = 0.03) and pressure-support ventilation (P = 0.05; R = 0.66) separately, as well as for cumulative dose of propofol (R = 0.66; P = 0.05) and piritramide (R = 0.79; P = 0.01). Conclusions Duration of mechanical ventilation is associated with a logarithmic decline in diaphragmatic force, which is compatible with the concept of VIDD. The observed decline may also be due to other potentially contributing factors such as sedatives/analgesics, sepsis, or others.

2010-01-01

134

An innovative approach for Steam Generator Pressure Control of a nuclear power plant  

Microsoft Academic Search

The main function of the Steam Generator Pressure Control (SGPC) Program is to match the power (heat) generation in the reactor core with the heat removal in the steam generators (SGs). For most of the designs these programs have been over simplified to cater to the limitation of the instrumentation and control, hardware and software. The main objective of balancing

Avinash J. Gaikwad; P. K. Vijayan; Sharad Bhartiya; Rajesh Kumar; H. G. Lele; K. K. Vaze

135

Factors predictive of attendance at clinic and blood pressure control in hypertensive patients  

Microsoft Academic Search

Poor compliance with appointments and drug treatment is one of the recognised factors preventing effective management of hypertension. Factors predictive of poor attendance and inadequate blood pressure control in patients attending a hypertension clinic were therefore determined using univariate analyses and a multivariate logistic model. Out of 1346 patients with blood pressure exceeding 160\\/95 mm Hg followed up for three

P Degoulet; J Menard; H A Vu; J L Golmard; C Devries; G Chatellier; P F Plouin

1983-01-01

136

A mixed GPC-H INFINITY robust cascade position-pressure control strategy for electropneumatic cylinders  

Microsoft Academic Search

A robust cascade strategy combining an outer position predictive control loop and an inner H? pressure control loop is proposed and tested on an electropneumatic testbed for parallel robotic applications. Two types of cylinders are tested, the standard double acting cylinder and the rodless one. A position\\/pressure difference (or force) strategy is developed and implemented. As the behavior of the

Lotfi Chikh; Philippe Poignet; François Pierrot; Cédric Baradat

2010-01-01

137

Rail pressure control of common rail diesel engine based on RBF neural network adaptive PID controller  

Microsoft Academic Search

The model of high pressure common rail system is designed and studied. In this paper, we propose a PID controller based on RBF neural network, and the corresponding control program is carried out under Matlab environment. When compared with traditional PID controller, RBF based PID controller shows its superiority having better dynamic response. Keywords-common rail; pressure control; RBF based PID

Zhongming Ji; Xuan Xie; Zhiqiang Sun; Peizhi Chen

2011-01-01

138

Research on rail pressure control of diesel engine based on genetic algorithm nonlinear PID  

Microsoft Academic Search

The performance of high pressure common-rail fuel injection system is influenced severely by the adjustment and stability of rail pressure in certain operating condition. A Nonlinear PID is designed to the control of pressure in the common rail. The optimal rail pressure control under different conditions is realized by online genetic algorithm adjustment of PID parameters. The control strategy and

WeiJun Ren; XianXin Shi; ShengJie Jiao; ChangJian Zhu; Qiong Zhang

2011-01-01

139

Investigation of Effect of Pressure Control System on BWR LOCA Phenomena Using ROSA-III Test Facility  

Microsoft Academic Search

A pressure control system failure test series was conducted at the Rig of Safety Assessment (ROSA)-III test facility to evaluate the effect of the pressure control system on thermal-hydraulic phenomena during a small break loss-of-coolant accident (LOCA) of a boiling water reactor (BWR). The break was assumed at the recirculation pump suction line. The pressure control system had no effect

Hiroshige KUMAMARU; Yasuo KOIZUMI; Yutaka KUKITA; Kanji TASAKA

1987-01-01

140

Pretest Predictions for Ventilation Tests  

SciTech Connect

The objective of this calculation is to predict the temperatures of the ventilating air, waste package surface, concrete pipe walls, and insulation that will be developed during the ventilation tests involving various test conditions. The results will be used as input to the following three areas: (1) Decisions regarding testing set-up and performance. (2) Assessing how best to scale the test phenomena measured. (3) Validating numerical approach for modeling continuous ventilation. The scope of the calculation is to identify the physical mechanisms and parameters related to thermal response in the ventilation tests, and develop and describe numerical methods that can be used to calculate the effects of continuous ventilation. Sensitivity studies to assess the impact of variation of linear power densities (linear heat loads) and ventilation air flow rates are included. The calculation is limited to thermal effect only.

Y. Sun; H. Yang; H.N. Kalia

2007-01-17

141

Ventilation in chest trauma  

PubMed Central

Chest trauma is one important factor for total morbidity and mortality in traumatized emergency patients. The complexity of injury in trauma patients makes it challenging to provide an optimal oxygenation while protecting the lung from further ventilator-induced injury to it. On the other hand, lung trauma needs to be treated on an individual basis, depending on the magnitude, location and type of lung or chest injury. Several aspects of ventilatory management in emergency patients are summarized herein and may give the clinician an overview of the treatment possibilities for chest trauma victims.

Richter, Torsten; Ragaller, Maximilian

2011-01-01

142

Radioaerosol ventilation imaging in ventilator-dependent patients. Technical considerations  

SciTech Connect

The differentiation of pulmonary embolism (PE) from regional ventilatory abnormalities accompanied by reduced perfusion requires contemporary perfusion and ventilation studies. Distinguishing these conditions in ventilator-dependent patients is aided by administering a Tc-99m aerosol to characterize regional ventilation, and by performing a conventional Tc-99m MAA perfusion study. The technique uses a simple in-house constructed apparatus. Simple photographic techniques suffice, but computer subtraction of perfusion from the combined perfusion-ventilation image renders interpretation easier if aerosol administration follows perfusion imaging. Multiple defects can be examined in a single study. Excluding normal or near-normal perfusion studies, PE was thought to be present in eight of 16 patients after perfusion imaging alone, but in only one of eight after added aerosol imaging. Angiography confirmed the diagnosis in that patient. Of the eight patients who had abnormal perfusion but were thought unlikely to have PE from the perfusion study alone, two had normal ventilation, and subsequently were shown to have PE by angiography. Because angiography was only performed on patients who were thought to have a high probability of PE on sequential perfusion-ventilation imaging, the true incidence of PE may have been higher. Aerosol ventilation imaging is a useful adjunct to perfusion imaging in patients on ventilators. It requires an efficient delivery system, particularly if aerosol administration follows perfusion imaging, as it does in this study.

Vezina, W.; Chamberlain, M.; Vinitski, S.; King, M.; Nicholson, R.; Morgan, W.K.

1985-11-01

143

Ventilation Host and Risk Area Techniques.  

National Technical Information Service (NTIS)

This study consisted of an investigation into several aspects of providing ventilation in counterforce risk- and host-area shelter facilities. Ventilation concepts, including the characteristics of methods for providing ventilation and the shelter charact...

S. B. York R. J. Reeves R. J. Wallace

1982-01-01

144

30 CFR 75.333 - Ventilation controls.  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 2010-07-01 false Ventilation controls. 75.333 Section 75.333 ...MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.333 Ventilation controls. (a) For purposes of this...

2010-07-01

145

30 CFR 57.8520 - Ventilation plan.  

Code of Federal Regulations, 2010 CFR

...2009-07-01 2009-07-01 false Ventilation plan. 57.8520 Section 57.8520...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Ventilation Underground Only § 57.8520 Ventilation plan. A plan of the mine...

2009-07-01

146

[Assisted ventilation at home].  

PubMed

In patients with chronic respiratory failure, in particular in those with accompanying wall-dependent restrictive syndrome (i.e. kyphoscoliosis, certain myopathies...) shortness of breath and sequelae of cor pulmonale usually limit quality of life distinctly. In particular repeated hospitalizations necessitated by remittent occurrence of severe respiratory decompensation, usually in the course of infections, reduce life quality and life expectancy. Thus, selected patients may benefit remarkably from a device for assisted ventilation at home as a technical measure with good results. The number of hospitalizations is markedly reduced, shortness of breath can even disappear completely, so that patients can regain social activity. The usually non-invasive technique (ventilation with nose-mask) is applied at night, so that disturbance is low for the patient and his surroundings. It is however necessary, that his financial burden and technical maintenance and servicing of materials is granted by an organisation, who is also able to provide safety for the patient and his family on a long term. PMID:8506437

Chevrolet, J C

1993-05-11

147

New Ventilated Isolation Cage  

PubMed Central

A multifunction lid has been developed for a commercially available transparent animal cage which permits feeding, watering, viewing, long-term holding, and local transport of laboratory rodents on experiment while isolating the surrounding environment. The cage is airtight except for its inlet and exhaust high-efficiency particulate air filters, and it is completely steam-sterilizable. Opening of the cage's feed and water ports causes an inrush of high velocity air which prevents back-migration of aerosols and permits feeding and watering while eliminating need for chemical vapor decontamination. Ventilation system design permits the holding in adjacent cages of animals infected with different organisms without danger of cross-contamination; leaves the animal room odor-free; reduces required bedding changes to twice a month or less, and provides investigators with capability to control precisely individual cage ventilation rates. Forty-eight cages can be conveniently placed on a standard NIH “shoebox” cage rack (60 inches wide × 28 inches deep × 74 inches high) fitted with a simple manifold exhaust system. The entire system is mobile, requiring only an electrical power outlet. Principal application of the caging system is in the area of preventing exposure of animal caretakers to pathogenic substances associated with the animal host, and in reducing handling of animals and their exposure to extraneous contamination. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 9

Cook, Reginald O.

1968-01-01

148

Emplacement Ventilation System  

SciTech Connect

The purpose of this analysis is to identify conceptual design options for the emplacement ventilation system, specifically within the emplacement drifts. The designs are based on the Enhanced Design Alternative (EDA) II concept developed during the license application design selection exercise as described in the ''License Application Design Selection Report'' (CRWMS M&O 1999a) and in the emplacement drift ''Ventilation Model'' (CRWMS M&O 2000c). The scope of this analysis, as outlined in the development plan (CRWMS M&O 2000a), includes the following tasks: (1) Description of the air flow path in the emplacement drifts. (2) Examination of the exhaust options for air exiting the emplacement drifts. (3) Examination of the air control options in the emplacement drifts. (4) Discussion of following system components and structures: emplacement isolation doors, portable shadow shield and exhaust main partition. The objective of this analysis is to support site recommendation through input to the system description documents. Off-normal conditions are not discussed in this analysis.

R. Vance

2000-04-05

149

Where to perform noninvasive ventilation?  

Microsoft Academic Search

Where to perform noninvasive ventilation? M.W. Elliott, M. Confalonieri, S. Nava. #ERS Journals Ltd 2002. ABSTRACT: Noninvasive positive-pressure ventilation (NPPV) has been shown to be a means of reducing the need for endotracheal intubation, which when effective reduces the complication rate and improves outcome. Because paralysis and sedation are not needed and because the patient is not necessarily dependent upon

M. W. Elliott; M. Confalonieri; S. Nava

2002-01-01

150

Reverse ventilation--perfusion mismatch  

SciTech Connect

Patients having lobar airway obstruction or consolidation usually have decreases of both ventilation and perfusion on lung scans. We report three patients in whom hypoxic vasoconstriction was apparently incomplete, resulting in a ''reversed'' ventilation-perfusion mismatch. Perfusion of the hypoxic lobe on the radionuclide scan was associated with metabolic alkalosis, pulmonary venous and pulmonary arterial hypertension in these patients.

Palmaz, J.C.; Barnett, C.A.; Reich, S.B.; Krumpe, P.E.; Farrer, P.A.

1984-01-01

151

Ventilation system with spiral recuperator  

Microsoft Academic Search

A new kind of longitudinal flow spiral recuperator for the heat recovery in ventilation systems of buildings was studied experimentally and analytically.The aim of this work is to analyze the possibility of using air handling units with new type of spiral recuperator in order to recover heat in ventilation systems of buildings. For the reason that the air flows are

Mariusz Adamski

2010-01-01

152

Recent advances in mechanical ventilation  

Microsoft Academic Search

Important advances have been made over the past decade towards understanding the optimal approach to ventilating patients with acute respiratory failure. Evidence now supports the use of noninvasive positive pressure ventilation in selected patients with hypercapnic respiratory failure and chronic obstructive pulmonary disease, cardiogenic pulmonary edema, and for facilitating the discontinuation of ventilatory support in patients with chronic pulmonary disease.

Carolyn S. Calfee; Michael A. Matthay

2005-01-01

153

Home ventilation in Northern Ireland.  

PubMed Central

Thirteen patients were identified as receiving assisted ventilation at home in Northern Ireland in 1994. Two patients have since died. An increasing number of patients are starting home ventilation, especially by nasal mask. Recognition of the needs of these patients and provision of care require further consideration.

Nugent, A. M.; Lyons, J. D.; Gleadhill, I. C.; MacMahon, J.

1996-01-01

154

Recent updates in mechanical ventilation  

PubMed Central

Recently, several studies have been performed to better outline the pathophysiology of acute respiratory failure and evaluate the therapeutic profile of different modes of ventilation and ventilator settings. Here we briefly report those we consider most relevant for daily intensive care unit clinical practice.

Bergamaschi, Valentina

2009-01-01

155

Alternative modalities of ventilation in acute respiratory failure.  

PubMed

Acute respiratory failure continues to complicate the management of critically ill trauma and surgical patients. Despite an increased understanding of the pathophysiology of this process, there is no golden bullet with which to stop or reverse it. Management remains directed toward maintenance of gas exchange and minimizing complications until such time as the process that initiated the respiratory failure has resolved and the lungs have an opportunity to recover. Continuous positive pressure ventilation with PEEP and oxygen is the conventional modality for achieving this goal. It is apparent that some patients are refractory to this therapy. In addition, there is evidence that alveolar injury may occur as a result of increasing airway pressures and shear forces. These authors have reviewed a number of modalities that seek to address these issues. IRV, whether pressure or volume controlled, appears at least able to provide adequate gas exchange in some patients who are refractory to conventional therapies. The same appears to be true for pressure control ventilation, airway pressure release ventilation, and volume control ventilation with a modified decelerating flow waveform. Whether any of these modalities will prove to alter outcome with respect to mortality remains to be seen. Work continues in the arena of extrapulmonary oxygenation. Results of recent studies are improved compared to the results of the NIH trial reflecting advances in technology, technique, and experience. The IVOX is a fascinating device that has been shown to effectively transfer respiratory gases, as has perfluorocarbon associated gas exchange. Whether these technologies will find a role in the treatment of adult respiratory failure awaits further study. PMID:7597555

Cole, F J; Shouse, B A

1995-01-01

156

Gastric intramural pH in mechanically ventilated patients.  

PubMed Central

BACKGROUND: The hypothesis that gastric intramural pH (pHi) is predictive of outcome in haemodynamically stable, mechanically ventilated patients was tested in 25 patients on assisted mechanical ventilation for respiratory failure. METHODS: Simultaneous samples of arterial blood and gastric juice were obtained from patients on assist control, synchronised intermittent and pressure control ventilation during the first 48 hours of mechanical ventilation. Gastric pHi was calculated from the equation: pHi= 6.1 + log HCO3/(gastric PCO2 X 0.03). The outcome was survival or death due to respiratory or circulatory failure within 45 days of admission. RESULTS: Gastric pHi proved to be a better predictor of outcome than all presently utilised parameters. Although all patients included in this study were haemodynamically stable and were similar for all laboratory indices, the only variable capable of accurately predicting outcome was gastric pHi. Patients with a normal arterial pH but a gastric intramural pH of less than 7.25 had an observed mortality of 66%. Standard severity of illness scores grossly underestimated mortality rates. The sensitivity and specificity of a gastric pHi value of less than 7.25 in predicting death were 86% and 83%, respectively. A receiver operator curve for all variables exaggerates the superiority of gastric pHi as a predictor of outcome. CONCLUSION: Low gastric pHi, a marker of gastrointestinal ischaemia, may occur in the presence of normal haemodynamics and may be used to predict severity of illness and mortality accurately.

Mohsenifar, Z; Collier, J; Koerner, S K

1996-01-01

157

PREMIER--a trial of lifestyle interventions for blood pressure control: intervention design and rationale.  

PubMed

Interventions encouraging adoption of healthy diets and increased physical activity are needed to achieve national goals for preventing and treating hypertension, cardiovascular disease, diabetes, and other chronic diseases. PREMIER was a multicenter clinical trial testing the effects of two lifestyle interventions on blood pressure control, compared with advice only. Both interventions implemented established national guidelines for blood pressure control (weight loss, reduced sodium and alcohol intake, and increased physical activity), and one intervention also included the Dietary Approaches to Stop Hypertension (DASH) diet. Both interventions focused on behavioral self-management, motivational enhancement, and personalized feedback. This article describes the design and evaluation approaches for these interventions. Evaluation of multicomponent lifestyle change interventions can help us understand the benefits and difficulties of making multiple lifestyle changes concurrently and the effects such changes can have on blood pressure, particularly in minorities at higher risk for hypertension. PMID:16803935

Funk, Kristine L; Elmer, Patricia J; Stevens, Victor J; Harsha, David W; Craddick, Shirley R; Lin, Pao-Hwa; Young, Deborah Rohm; Champagne, Catherine M; Brantley, Phillip J; McCarron, Phyllis B; Simons-Morton, Denise G; Appel, Lawrence J

2006-06-27

158

Effect of intensive blood pressure control on the course of type 1 diabetic nephropathy  

Microsoft Academic Search

Diabetic nephropathy is the most common cause of end-stage renal disease in the United States. We undertook a study to assess the impact of assignment to different levels of blood pressure control on the course of type 1 diabetic nephropathy in patients receiving angiotensin-converting enzyme (ACE) inhibitor therapy. We also examined the long-term course of this well-characterized cohort of patients

Julia Breyer Lewis; Tomas Berl; Raymond P. Bain; Richard D. Rohde; Edmund J. Lewis

1999-01-01

159

Experimental research on charging characteristics of a solar photovoltaic system by the pressure-control method  

Microsoft Academic Search

The charging characteristics of the valve-regulated lead acid (VRLA) battery driven by solar energy were experimentally studied\\u000a through the pressure-control method in this paper. The aims of the research were to increase charging efficiency to make the\\u000a most of solar energy and to improve charging quality to prolong life of battery. The charging process of a 12 V 12 A·h

Hua Zhu; Zhang-lu Xu; Zi-juan Cao

2011-01-01

160

Porcine CD74 is involved in the inflammatory response activated by nuclear factor kappa B during porcine circovirus type 2 (PCV-2) infection.  

PubMed

Human CD74 induces a signalling cascade that results in the activation of nuclear factor kappa B (NF-?B); however, porcine CD74 has not been widely studied. In this study, we show that porcine CD74 is mainly expressed in cells of the macrophage lineage and can be induced by lipopolysaccharide (LPS), polyinosinic acid-polycytidylic acid [Poly(I:C)], and infection with porcine circovirus type 2 (PCV2) in vitro. In addition, we confirmed that porcine CD74 can activate NF-?B by promoting I?B? degradation and nuclear translocation of p65. Furthermore, the transcription of NF-?B-regulated genes [Interleukin-6 (IL-6), Interleukin-8 (IL-8), and COX-2] was upregulated in response to the overexpression of porcine CD74. In general, porcine CD74 significantly enhanced the inflammatory response by regulating the NF-?B signalling pathway during PCV2 infection, which suggests that porcine CD74 may be implicated in the pathogenesis of PCV2 infection. PMID:23736979

Zhang, Hengling; Liu, Chong; Cheng, Shuang; Wang, Xiaofei; Li, Wentao; Charreyre, Catherine; Audonnet, Jean Christophe; He, Qigai

2013-06-05

161

[Mechanical ventilation in pediatrics (III). Weaning, complications and other types of ventilation. High-frequency ventilation].  

PubMed

In the era of lung-protective ventilation strategies, high frequency oscillatory ventilation (HFOV) has attracted renewed interest and its use has dramatically increased in neonatal and pediatric intensive care units. HFOV is able to reduce ventilator-induced lung injury by limiting the incidence of volutrauma, atelectrauma, barotrauma and biotrauma. During HFOV, adequate oxygenation and ventilation is achieved by using low tidal volumes and small pressure swings at supraphysiologic frequencies. Unlike other high-frequency ventilation modes, HFOV has an active expiration phase. HFOV constitutes a safe and successful ventilation mode for managing pediatric patients with respiratory insufficiency refractory to optimized conventional mechanical ventilation and provides better results when initiated early. However, the elective use of HFOV requires further studies to identify its benefits over conventional modes of mechanical ventilation and to support its routine use as a first line therapy. In the present article, the Respiratory Working Group of the Spanish Society Pediatric Critical Care reviews the main issues in the pediatric application of HFOV. In addition, a general practical protocol and specific management strategies, as well as the monitoring, patient care and other special features of the use of HFOV in the pediatric setting, are discussed. PMID:14562843

Martinón-Torres, F; Ibarra de la Rosa, I; Fernández Sanmartín, M; García Menor, E; Marinón Sánchez, J M

2003-08-01

162

A care bundle approach for prevention of ventilator-associated pneumonia.  

PubMed

Implementation of care bundles for prevention of ventilator-associated pneumonia (VAP) and its impact on patient outcomes requires validation with long-term follow-up. A collaborative multi-centre cohort study was conducted in five Spanish adult intensive-care units. A care bundle approach based on five measures was implemented after a 3-month baseline period, and compliance, VAP rates, intensive-care unit length of stay (ICU LOS) and duration of mechanical ventilation were prospectively recorded for 16 months. There were 149 patients in the baseline period and 885 after the intervention. Compliance with all measures after intervention was <30% (264/885). In spite of this, VAP incidence decreased from 15.5% (23/149) to 11.7% (104/885), after the intervention (p <0.05). This reduction was significantly associated with hand hygiene (OR = 0.35), intra-cuff pressure control (OR = 0.21), oral hygiene (OR = 0.23) and sedation control (OR = 0.51). Use of the care bundle was associated with an incidence risk ratio of VAP of 0.78 (95% CI 0.15-0.99). We documented a reduction of median ICU LOS (from 10 to 6 days) and duration of mechanical ventilation (from 8 to 4 days) for patients with full bundle compliance (intervention period). Efforts on VAP prevention and outcome improvement should focus on achieving higher compliance in hand and oral hygiene, sedation protocols and intracuff pressure control. PMID:22439889

Rello, J; Afonso, E; Lisboa, T; Ricart, M; Balsera, B; Rovira, A; Valles, J; Diaz, E

2012-03-22

163

Partial liquid ventilation.  

PubMed

Mortality from the adult respiratory distress syndrome (ARDS) and the infant respiratory distress syndrome remains high despite numerous interventions and modalities. Perfluorocarbons (PFC) are inert liquids that can dissolve large amounts of oxygen and carbon dioxide and can be used as respiratory media. Partial liquid ventilation uses PFC to partially fill the lungs of patients with ARDS to improve gas exchange and support them. Studies in animals and humans (mostly neonates) using perflubron, which is currently the only PFC approved for clinical use, have shown that they are safe and effective in improving oxygenation. In this article the rationale of the technique, its historical background, and animal and clinical data to date are reviewed. PMID:16088730

Hadjiliadis, D

2000-01-01

164

Estimation of Lung Ventilation  

NASA Astrophysics Data System (ADS)

Since the primary function of the lung is gas exchange, ventilation can be interpreted as an index of lung function in addition to perfusion. Injury and disease processes can alter lung function on a global and/or a local level. MDCT can be used to acquire multiple static breath-hold CT images of the lung taken at different lung volumes, or with proper respiratory control, 4DCT images of the lung reconstructed at different respiratory phases. Image registration can be applied to this data to estimate a deformation field that transforms the lung from one volume configuration to the other. This deformation field can be analyzed to estimate local lung tissue expansion, calculate voxel-by-voxel intensity change, and make biomechanical measurements. The physiologic significance of the registration-based measures of respiratory function can be established by comparing to more conventional measurements, such as nuclear medicine or contrast wash-in/wash-out studies with CT or MR. An important emerging application of these methods is the detection of pulmonary function change in subjects undergoing radiation therapy (RT) for lung cancer. During RT, treatment is commonly limited to sub-therapeutic doses due to unintended toxicity to normal lung tissue. Measurement of pulmonary function may be useful as a planning tool during RT planning, may be useful for tracking the progression of toxicity to nearby normal tissue during RT, and can be used to evaluate the effectiveness of a treatment post-therapy. This chapter reviews the basic measures to estimate regional ventilation from image registration of CT images, the comparison of them to the existing golden standard and the application in radiation therapy.

Ding, Kai; Cao, Kunlin; Du, Kaifang; Amelon, Ryan; Christensen, Gary E.; Raghavan, Madhavan; Reinhardt, Joseph M.

165

46 CFR 153.312 - Ventilation system standards.  

Code of Federal Regulations, 2012 CFR

...ft) from openings into or ventilation intakes for, accommodation or service spaces. (b) A ventilation system must not recycle vapors from ventilation discharges. (c) Except for the space served by the ventilation duct, a ventilation duct...

2012-10-01

166

46 CFR 153.312 - Ventilation system standards.  

Code of Federal Regulations, 2011 CFR

...ft) from openings into or ventilation intakes for, accommodation or service spaces. (b) A ventilation system must not recycle vapors from ventilation discharges. (c) Except for the space served by the ventilation duct, a ventilation duct...

2011-10-01

167

Subsurface Ventilation System Description Document  

SciTech Connect

The Subsurface Ventilation System supports the construction and operation of the subsurface repository by providing air for personnel and equipment and temperature control for the underground areas. Although the system is located underground, some equipment and features may be housed or located above ground. The system ventilates the underground by providing ambient air from the surface throughout the subsurface development and emplacement areas. The system provides fresh air for a safe work environment and supports potential retrieval operations by ventilating and cooling emplacement drifts. The system maintains compliance within the limits established for approved air quality standards. The system maintains separate ventilation between the development and waste emplacement areas. The system shall remove a portion of the heat generated by the waste packages during preclosure to support thermal goals. The system provides temperature control by reducing drift temperature to support potential retrieval operations. The ventilation system has the capability to ventilate selected drifts during emplacement and retrieval operations. The Subsurface Facility System is the main interface with the Subsurface Ventilation System. The location of the ducting, seals, filters, fans, emplacement doors, regulators, and electronic controls are within the envelope created by the Ground Control System in the Subsurface Facility System. The Subsurface Ventilation System also interfaces with the Subsurface Electrical System for power, the Monitored Geologic Repository Operations Monitoring and Control System to ensure proper and safe operation, the Safeguards and Security System for access to the emplacement drifts, the Subsurface Fire Protection System for fire safety, the Emplacement Drift System for repository performance, and the Backfill Emplacement and Subsurface Excavation Systems to support ventilation needs.

NONE

2000-10-12

168

Subsurface Ventilation System Description Document  

SciTech Connect

The Subsurface Ventilation System supports the construction and operation of the subsurface repository by providing air for personnel and equipment and temperature control for the underground areas. Although the system is located underground, some equipment and features may be housed or located above ground. The system ventilates the underground by providing ambient air from the surface throughout the subsurface development and emplacement areas. The system provides fresh air for a safe work environment and supports potential retrieval operations by ventilating and cooling emplacement drifts. The system maintains compliance within the limits established for approved air quality standards. The system maintains separate ventilation between the development and waste emplacement areas. The system shall remove a portion of the heat generated by the waste packages during preclosure to support thermal goals. The system provides temperature control by reducing drift temperature to support potential retrieval operations. The ventilation system has the capability to ventilate selected drifts during emplacement and retrieval operations. The Subsurface Facility System is the main interface with the Subsurface Ventilation System. The location of the ducting, seals, filters, fans, emplacement doors, regulators, and electronic controls are within the envelope created by the Ground Control System in the Subsurface Facility System. The Subsurface Ventilation System also interfaces with the Subsurface Electrical System for power, the Monitored Geologic Repository Operations Monitoring and Control System to ensure proper and safe operation, the Safeguards and Security System for access to the emplacement drifts, the Subsurface Fire Protection System for fire safety, the Emplacement Drift System for repository performance, and the Backfill Emplacement and Subsurface Excavation Systems to support ventilation needs.

Eric Loros

2001-07-25

169

[Ventilator associated acute lung injury].  

PubMed

Mechanical ventilation plays a central role in the critical care setting; but its use is closely related with some life threatening complications as nosocomial pneumonia and low cardiac performance. One of the most severe complications is called ventilator-associated lung injury (VALI) and it includes: Barotrauma, volutrauma, atelectrauma, biotrauma and oxygen-mediated toxic effects and it is related with an inflammatory response secondary to the stretching and recruitment process of alveoli within mechanical ventilation. The use of some protective ventilatory strategies has lowered the mortality rate 10% approximately. PMID:16187708

Namendys-Silva, Silvio Antonio; Posadas-Calleja, Juan Gabriel

170

Energy Analysis of Ventilated Roof  

Microsoft Academic Search

\\u000a The thermal performance of the building envelope is an important requirement for guaranteeing both a comfortable indoor climate\\u000a and building’s energy efficiency.\\u000a \\u000a \\u000a Ventilated facades and ventilated roofs could be considered as a passive cooling system that contribute to realize low energy\\u000a building.\\u000a \\u000a \\u000a \\u000a The energy advantages provided by the ventilation of structures, during the summer, is the reduction of the cooling

F. Patania; A. Gagliano; F. Nocera; A. Ferlito; A. Galesi

171

Ventilator-delivered mask ventilation compared with three standard methods of mask ventilation in a manikin model  

Microsoft Academic Search

BackgroundLittle is known regarding the variations in effective ventilation during bag and mask resuscitation with standard methods compared with that delivered by ventilator-delivered mask ventilation (VDMV).AimTo measure the variations in delivered airway pressure, tidal volume (TV), minute ventilation (MV) and inspiratory time during a 3-min period of mask ventilation comparing VDMV with three commonly used hand-delivered methods of bag and

M. B. Tracy; J. Klimek; H. Coughtrey; V. Shingde; G. Ponnampalam; M. Hinder; R. Maheshwari; S. K. Tracy

2011-01-01

172

Preoperational test, vent building ventilation system  

SciTech Connect

Preoperational Test Procedure for Vent Building Ventilation System, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The Vent Building ventilation system provides ventilation, heating, cooling, and zone confinement control for the W-030 Project Vent Building. The tests verify correct System operation and correct indications displayed by the central Monitor and Control system.

Clifton, F.T., Westinghouse Hanford

1996-08-20

173

Use of Adaptive Support Ventilation (ASV) in Ventilator Associated Pneumonia (VAP) - A Case Report  

PubMed Central

Summary Prolonged ventilation leads to a higher incidence of ventilator associated pneumonia(VAP) resulting in ventilator dependency, increased costs and subsequent weaning failures. Prevention and aggressive treatment of VAP along with patient friendly newer modes of ventilation like adaptive support ventilation go a long way in successful management of these cases.

Kath, Bipphy; Hemanth, N; Marella, Prashanti; Rao, M H

2009-01-01

174

Equivalence in Ventilation and Indoor Air Quality  

SciTech Connect

We ventilate buildings to provide acceptable indoor air quality (IAQ). Ventilation standards (such as American Society of Heating, Refrigerating, and Air-Conditioning Enginners [ASHRAE] Standard 62) specify minimum ventilation rates without taking into account the impact of those rates on IAQ. Innovative ventilation management is often a desirable element of reducing energy consumption or improving IAQ or comfort. Variable ventilation is one innovative strategy. To use variable ventilation in a way that meets standards, it is necessary to have a method for determining equivalence in terms of either ventilation or indoor air quality. This study develops methods to calculate either equivalent ventilation or equivalent IAQ. We demonstrate that equivalent ventilation can be used as the basis for dynamic ventilation control, reducing peak load and infiltration of outdoor contaminants. We also show that equivalent IAQ could allow some contaminants to exceed current standards if other contaminants are more stringently controlled.

Sherman, Max; Walker, Iain; Logue, Jennifer

2011-08-01

175

Performance Improvement of Scroll Compressors for Air Conditioners Using a Back-Pressure Control System  

NASA Astrophysics Data System (ADS)

The performance of scroll compressors using the new back-pressure control system is much better than that of conventional compressors, especially under the cooling half-load condition at a higher suction pressure and a lower discharge pressure. Optimum performance is obtained under all operating conditions by varying the backpr-pessure at a level that is a constant amount above the suction pressure. This reduces friction at the thrust bearing between the orbiting and fixed scrolls. In this paper, we discuss the theoretical analysis of backpressure control method.

Tsubono, Isamu; Hayase, Isao; Takebayashi, Masahiro; Inaba, Koichi; Sekiguchi, Koichi; Shimada, Atsushi

176

Ventilation Model and Analysis Report  

SciTech Connect

This model and analysis report develops, validates, and implements a conceptual model for heat transfer in and around a ventilated emplacement drift. This conceptual model includes thermal radiation between the waste package and the drift wall, convection from the waste package and drift wall surfaces into the flowing air, and conduction in the surrounding host rock. These heat transfer processes are coupled and vary both temporally and spatially, so numerical and analytical methods are used to implement the mathematical equations which describe the conceptual model. These numerical and analytical methods predict the transient response of the system, at the drift scale, in terms of spatially varying temperatures and ventilation efficiencies. The ventilation efficiency describes the effectiveness of the ventilation process in removing radionuclide decay heat from the drift environment. An alternative conceptual model is also developed which evaluates the influence of water and water vapor mass transport on the ventilation efficiency. These effects are described using analytical methods which bound the contribution of latent heat to the system, quantify the effects of varying degrees of host rock saturation (and hence host rock thermal conductivity) on the ventilation efficiency, and evaluate the effects of vapor and enhanced vapor diffusion on the host rock thermal conductivity.

V. Chipman

2003-07-18

177

ALTERNATIVE PROCESSING TECHNOLOGIES TO REDUCE TRANS ACID CONTENTS OF FOOD OILS: INTERESTERIFICATION, PLANT BREEDING, AND PRESSURE CONTROLLED HYDROGENATION  

Technology Transfer Automated Retrieval System (TEKTRAN)

Alternative processing strategies to reduce trans acid contents of food oils include interesterification, genetic and plant breeding for triglyceride and fatty acid composition and pressure controlled hydrogenation. This paper will review research in these areas. Random interesterification of liqu...

178

New Energy-Saving Type of Ventilation for Loom Workshop  

Microsoft Academic Search

A new energy-saving type of ventilation named large and small zone ventilation for loom workshop is proposed in this paper. Large and small zone ventilation means there are two ventilation systems for loom workshop, where large zone ventilation for total loom workshop and small zone ventilation for loom surface is used. Large zone ventilation is mainly used to keep temperature

Zhu Caixia; Zhao Nannan; Gao Long; Song Gaoju

2009-01-01

179

Development of a pressure control system for brace treatment of scoliosis.  

PubMed

Bracing is a common nonsurgical treatment for scoliosis, but its effectiveness has been debated. Some clinical studies have shown efficacy of brace treatment is correlated to how the brace has been worn. The more often the patients wear their braces to the prescribed tightness as well as the prescribed length of wear each day, the better the treatment outcome. A system of four wireless pressure control devices was developed to understand brace wear-time and regulate a target pressure range at the brace-body interface. Each pressure control device could function independently and be embedded in the brace at key pressure areas. Such a system could improve the quality of brace wear-making the treatment more effective and refining our understanding of the three-pressure-point brace treatment concept during daily activities. This paper reports the system development and validation. The system was tested on four healthy subjects for 2 h without pressure regulation and 2 h with regulation. The results show that the pressure regulation doubled the time spent in a desired pressure range on average (from 31% to 62%). Brace-wear time was logged correctly. The system was also validated through a seven-day continuous test, and a fully charged battery could run for 30 days without requiring recharge. PMID:22514207

Chalmers, Eric; Lou, Edmond; Hill, Doug; Zhao, Vicky H; Wong, Man-Sang

2012-04-13

180

Nasopharyngeal Carriage of Pneumococci Four Years after Community-Wide Vaccination with PCV-7 in The Gambia: Long-Term Evaluation of a Cluster Randomized Trial  

PubMed Central

Background A village-randomized trial of a seven-valent pneumococcal-conjugate-vaccine (PCV-7) conducted in rural Gambia showed a decrease of vaccine-type (VT) and a non-significant increase in non-vaccine-type (NVT) nasopharyngeal carriage of pneumococci two years after vaccination. Here, we report findings four years after vaccination. Methods PCV-7 was given to all children below 30 months of age enrolled in the trial and to those born during its course in all study villages. Villages were randomized (older children and adults) to receive PCV-7 (wholly vaccinated villages) or serogroup-C-meningococcal-conjugate-vaccine (partly vaccinated villages). Cross-sectional surveys (CSS) to collect nasopharyngeal swabs were conducted before and at various intervals after vaccination. Sixteen of these randomized villages (8 wholly vaccinated and 8 partly vaccinated) participated in a CSS conducted four years after vaccination started. Results Four years after vaccination, the prevalence of VT pneumococcal carriage was slightly higher in partly than in wholly vaccinated villages [6.4% versus 3.9% (p?=?0.120)] compared to 24.4% in the pre-vaccination CSS (p<0.001). Prevalence of NVT four years after vaccination was similar between study groups [32.7% versus 29.8% (p?=?0.392), respectively] compared to 51.1% in the pre-vaccination CSS (p<0.001). Four years after vaccination started, lower prevalence of serotype 6A was detected in wholly vaccinated than in partly vaccinated villages (1.6% versus 3.5%, p?=?0.093) whilst the prevalence of serotype 19A was similar between groups (2.9% versus 2.5%, p?=?0.779). The most prevalent serotype 19A clone was ST 847. The most prevalent serotype 6A clone before vaccination was ST3324 whilst after vaccination ST913 and ST1737 predominated. Fourteen out of 26 STs detected among the serotype 6A isolates were new while no new 19A serotype ST was found. Conclusions The decline in prevalence of VT pneumococci seen shortly after PCV-7 vaccination was sustained four years later with only a small difference between study arms. No significant serotype replacement was detected. Trial Registration ClinicalTrials.gov ISRCTN51695599

Roca, Anna; Dione, Michel M.; Bojang, Abdoulie; Townend, John; Egere, Uzochukwu; Darboe, Ousainou; Howie, Stephen R. C.; Hill, Philip C.; Adegbola, Richard A.; Greenwood, Brian M.; Antonio, Martin

2013-01-01

181

Residential ventilation standards scoping study  

SciTech Connect

The goals of this scoping study are to identify research needed to develop improved ventilation standards for California's Title 24 Building Energy Efficiency Standards. The 2008 Title 24 Standards are the primary target for the outcome of this research, but this scoping study is not limited to that timeframe. We prepared this scoping study to provide the California Energy Commission with broad and flexible options for developing a research plan to advance the standards. This document presents the findings of a scoping study commissioned by the Public Interest Energy Research (PIER) program of the California Energy Commission to determine what research is necessary to develop new residential ventilation requirements for California. This study is one of three companion efforts needed to complete the job of determining the ventilation needs of California residences, determining the bases for setting residential ventilation requirements, and determining appropriate ventilation technologies to meet these needs and requirements in an energy efficient manner. Rather than providing research results, this scoping study identifies important research questions along with the level of effort necessary to address these questions and the costs, risks, and benefits of pursuing alternative research questions. In approaching these questions and corresponding levels of effort, feasibility and timing were important considerations. The Commission has specified Summer 2005 as the latest date for completing this research in time to update the 2008 version of California's Energy Code (Title 24).

McKone, Thomas E.; Sherman, Max H.

2003-10-01

182

A new conventional and high-frequency ventilator for small animals.  

PubMed

A pressure limited, time controlled ventilator has been designed especially for studies on experimental animals with severe respiratory distress syndrome (SRDS). Inspiration: Expiration (I:E) ratio (1:99-99:1) and frequency can be changed independently. Frequency ranged from 1 to 199/min in conventional ventilation (CV), while in high-frequency jet ventilation (HFJV) from 1 to 30 Hz. The gas delivery system consists of 3 magnetic valves (inspiration, expiration and HFJV, respectively) to ensure superposition of CV with HFJ or to use them separately. A monitoring unit switches off inspiration gas sources during HFJV if intratracheal pressure exceeds the alarm threshold. The device has been used in the following animal models: premature newborn rabbits with surfactant deficient lungs, emphysematous rats and guinea pigs as well as dogs and rabbits with SRDS due to lung lavage. Ventilation was most effective with an I:E ratio of 4:1 during pressure controlled CV, whereas during HFJV optimum gas exchange could be maintained with an I:E ratio of 1:4 and a frequency of 15 Hz in beagle dogs and 10 Hz in rabbits, respectively. PMID:3324645

Merker, G; Oddoy, A; Adloff, G; Becher, G

1987-01-01

183

A Thermocouple Homogeneity Scanner Based on an Open Pressure-Controlled Water Heatpipe  

NASA Astrophysics Data System (ADS)

This paper demonstrates a low-cost, high-performance thermocouple homogeneity scanner based on a pressure-controlled water heatpipe that is open to the atmosphere. With this arrangement, very much like a steam-point apparatus, the atmosphere provides the controlled pressure and the buffer gas for the heatpipe, and the isothermal zone is close to 100 °C. The thermocouple is inserted into the steam within the heatpipe through a plastic membrane so that the gradient is imposed over a spatial region determined primarily by heat flow within the thermocouple body, and can be as small as a few millimeters. The paper explains the construction of the scanner, and presents results of example scans demonstrating the uniformity and resolution of the scanner.

White, D. R.; Mason, R. S.

2010-09-01

184

A comparison of fuzzy logic-PID control strategies for PWR pressurizer control  

SciTech Connect

This paper describes the results obtained from a comparison performed between classical proportional-integral-derivative (PID) and fuzzy logic (FL) controlling the pressure in a pressurized water reactor (PWR). The two methodologies have been tested under various transient scenarios, and their performances are evaluated with respect to robustness and on-time response to external stimuli. One of the main concerns in the safe operation of PWR is the pressure control in the primary side of the system. In order to maintain the pressure in a PWR at the desired level, the pressurizer component equipped with sprayers, heaters, and safety relief valves is used. The control strategy in a Westinghouse PWR is implemented with a PID controller that initiates either the electric heaters or the sprayers, depending on the direction of the coolant pressure deviation from the setpoint.

Kavaklioglu, K.; Ikonomopoulos, A. (Univ. of Tennessee, Knoxville (United States))

1993-01-01

185

Role of olmesartan in combination therapy in blood pressure control and vascular function  

PubMed Central

Angiotensin receptor blockers have emerged as a first-line therapy in the management of hypertension and hypertension-related comorbidities. Since national and international guidelines have stressed the need to control blood pressure to <140/90 mmHg in uncomplicated hypertension and <130/80 mmHg in those with associated comorbidities such as diabetes or chronic kidney disease, these goal blood pressures can only be achieved through combination therapy. Of several drugs that can be effectively combined to attain the recommended blood pressure goals, fixed-dose combinations of angiotensin receptor blockers and the calcium channel blocker amlodipine provide additive antihypertensive effects associated with a safe profile and increased adherence to therapy. In this article, we review the evidence regarding the beneficial effects of renin–angiotensin system blockade with olmesartan medoxomil and amlodipine in terms of blood pressure control and improvement of vascular function and target organ damage.

Ferrario, Carlos M; Smith, Ronald D

2010-01-01

186

Transmural pressure control of prorenin processing and secretion in diabetic rat juxtaglomerular cells.  

PubMed

In diabetic patients, the elevation of plasma prorenin levels or arterial pressure is correlated with the severity of diabetic nephropathy. This study was designed to assess the effects of transmural pressure on prorenin regulation in juxtaglomerular (JG) cells from diabetes rats. The JG cells, harvested from rats intraperitoneally injected with streptozotocin 7 (early-diabetic) or 28 (late-diabetic) days previously, were exposed to atmospheric pressure (AP) and AP+40 mmHg for 12 h, and the renin secretion rate (RSR), prorenin secretion rate (PRSR), active renin content (ARC), prorenin content (PRC), and total renin content (TRC) were determined. Exposure of control JG cells to AP+40-mmHg significantly decreased RSR, PRSR, and ARC and significantly increased PRC without affecting TRC, suggesting the occurrence of pressure-mediated inhibition of prorenin processing and secretion. Exposure of early-diabetic and late-diabetic cells to AP+40-mmHg significantly decreased ARC and significantly increased PRC without affecting RSR, PRSR, or TRC. The changes in ARC and PRC were similar in the control and early-diabetic cells, but greater changes were observed in late-diabetic cells. However, when streptozotocin-treated rats were continuously treated with insulin (9 U/kg/day), the transmural pressure control of prorenin in JG cells was similar to that observed in the JG cells from control rats. In late-diabetic cells, treatment with a phospholipase C inhibitor did not alter the pressure control of ARC or PRC; however, treatment with a phospholipase D inhibitor did inhibit the changes in ARC and PRC with transmural pressure. Thus, pressure-mediated inhibition of prorenin secretion from JG cells has already been impaired in early diabetes. Pressure-induced inhibition of prorenin processing in JG cells via phospholipase D-dependent pathways is enhanced in late diabetes. PMID:12862207

Hirota, Nobuhisa; Ichihara, Atsuhiro; Koura, Yukako; Tada, Yuko; Hayashi, Matsuhiko; Saruta, Takao

2003-06-01

187

Regional Blood Flow in Respiratory Muscles During Partial Ventilatory Assistance in Rabbits  

Microsoft Academic Search

We tested the hypothesis that even partial ventilatory assistancewouldreducerespiratorymusclebloodflow to levels similar to those found during control mechan- icalventilation(CMV).Threelevelsofpressuresupport ventilation(PSV)and2CMVsettingswerecomparedin 10 rabbits. PSV 0, 6, and 12 cm H2O, under continuous positive airway pressure mode, were applied, and then pressure control ventilation (PCV) values of 6 (36 breaths\\/min) and 12 cm H2O (18 per breaths\\/min) were applied to each CMV

Akinori Uchiyama; Yuji Fujino; Kikumi Hosotsubo; Eriko Miyoshi; Takashi Mashimo; Masaji Nishimura

2006-01-01

188

46 CFR 108.181 - Ventilation for enclosed spaces.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 false Ventilation for enclosed spaces. 108.181 Section 108.181 Shipping ...Ventilation § 108.181 Ventilation for enclosed spaces. (a) Each enclosed space must be vented or ventilated. (b)...

2012-10-01

189

Efficacy of Intermittent Ventilation for Providing Acceptable Indoor Air Quality.  

National Technical Information Service (NTIS)

Ventilation standards and guidelines typically treat ventilation as a constant and specify its value. In many circumstances a designer wishes to use intermittent ventilation, rather than constant ventilation, but there are no easy equivalencies available....

M. H. Sherman

2004-01-01

190

Commissioning Ventilated Containment Systems in the Laboratory.  

National Technical Information Service (NTIS)

This Best Practices Guide focuses on the specialized approaches required for ventilated containment systems, understood to be all components that drive and control ventilated enclosures and local exhaust systems within the laboratory. Geared toward archit...

2008-01-01

191

14 CFR 252.9 - Ventilation systems.  

Code of Federal Regulations, 2013 CFR

...DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS SMOKING ABOARD AIRCRAFT § 252.9 Ventilation systems. Air carriers shall prohibit smoking whenever the ventilation system is not fully functioning. Fully...

2013-01-01

192

21 CFR 868.5975 - Ventilator tubing.  

Code of Federal Regulations, 2013 CFR

...Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5975 Ventilator tubing. (a) Identification. Ventilator tubing is...

2013-04-01

193

JAMA Patient Page: Ventilator-Associated Pneumonia  

MedlinePLUS

... rare cases, open lung biopsy to obtain lung tissue may be done. • Antibiotics remain the cornerstone of therapy for ventilator-associated pnuemonia. Choice of antibiotic is guided by bacteria culture results. • Because ventilator-associated pnuemonia occurs in hospitalized ...

194

Comparative Tests on Calves. Insulation - Ventilation - Heating.  

National Technical Information Service (NTIS)

Comparative tests have been carried out in 3 calf houses, of which one was insulated, mechanically ventilated and heated (KA-1), another was insulated and had an automatically regulated natural ventilation system without heating (KA-2), and the third hous...

K. Hansen

1984-01-01

195

Equipment needs for noninvasive mechanical ventilation  

Microsoft Academic Search

ABSTRACT: Noninvasive mechanical,ventilation (NIV) has a long tradition for the treatment of chronic respiratory failure and more recently has also been applied in acute respiratory failure. Based on this experience both critical care ventilators and portable ventilators are used to perform,NIV. The individual choice of ventilator type should depend on the patient9s condition and also on the expertise of attending

B. Schonhofer; S. Sortor-Leger

2002-01-01

196

Ventilator-Associated Pneumonia: A Review  

Microsoft Academic Search

Ventilator-associated pneumonia is the most frequent intensive care unit (ICU)-related infection in patients requiring mechanical ventilation. In contrast to other ICU-related infections, which have a low mortality rate, the mortality rate for ventilator-associated pneumonia ranges from 20% to 50%. These clinically significant infections prolong duration of mechanical ventilation and ICU length of stay, underscoring the financial burden these infections impose

Kimberly A. Davis

2006-01-01

197

[Mechanical ventilation in pediatrics (III). Weaning, complications and other types of ventilation. Compications of mechanical ventilation].  

PubMed

Mechanical ventilation can produce multiple complications. The most important acute complications are mechanical problems (respirator failure, problems with the connections and circuit, incorrect parameters or alarms), problems in the airway (disconnection, extubation, mal-positioning of the endotracheal tube, leaks, nose erosions, obstruction of the endotracheal tube due to secretions or kinking, mainstem bronchus intubation, bronchospasm, postextubation croup), pulmonary complications (ventilator-induced lung injury with barotrauma, volutrauma and biotrauma), hemodynamic complications, nosocomial infections (tracheobronchitis, pneumonia, otitis, sinusitis), failure of adjustment of the respirator to the patient, and nutritional complications. The most important chronic problems are subglottal stenosis, chronic pulmonary injury, and psychological alterations. PMID:14562840

Reina Ferragut, C; López-Herce, J

2003-08-01

198

Noninvasive Positive Pressure Ventilation in burns  

Microsoft Academic Search

Objective: Acute respiratory failure is a common complication of the severely burn-injured patient. Endotracheal intubation and mechanical ventilation is associated with a high rate of complications. Noninvasive Positive Pressure Ventilation (NIPPV) has been shown to be as effective as conventional ventilation in improving gas exchange and is associated with fewer complications with patients in acute hypercapnic and hypoxaemic respiratory failure.

S. T Smailes

2002-01-01

199

Cardiovascular Effects of Mechanical Ventilation  

Microsoft Academic Search

Objective: To review the cardiovascular effects of spontaneous breathing and mechanical ventilation in healthy and pathological states. Data sources: A review of articles published in peer-reviewed journals from 1966 to 1998 and identified through a MEDLINE search on cardiopulmonary interaction. Summary of review: Respiration has a hydraulic influence upon cardiovascular function. Pulmonary and cardiac pathology alter this interaction. Spontaneous inspiration

G. J. DUKE

1999-01-01

200

Fire Service Training. Ventilation. (Revised).  

ERIC Educational Resources Information Center

|One of a set of fourteen outlines for use in a course to train novice firemen, this guide covers ventilation practices and principles. As background, subjects such as heat transmission and building construction are included. The three objectives of this part of the course are to enable the fireman to (1) rescue trapped victims, (2) locate fires…

North Carolina State Dept. of Community Colleges, Raleigh.

201

Monitoring for ventilation and airtightness  

SciTech Connect

The object of this paper is to show how the monitoring of key IAQ parameters can provide feedback on building performance in the areas of ventilation and airtightness. The availability of this information can then lead to the more effective operation of the building and its HVAC system because the operators will have better information on system operation. The monitoring of carbon dioxide (CO{sub 2}) concentrations, for instance, provides feedback on many aspects of HVAC performance includes information on the adequacy of ventilation, the uniformity of ventilation, and the effectiveness of the overnight purge. Coupled with the monitoring of humidity, feedback on airtightness and energy efficiency also becomes available. The monitoring of multiple parameters of the indoor environment at strategically selected multiple locations in buildings, therefore, can provide important information on HVAC performance. As such, it can improve the management of buildings by reducing the amount of uncertainty in this performance. The better the operators know what the HVAC system is doing, the better they can optimize its performance for both ventilation adequacy and minimum energy use.

Bearg, D.W.

2000-07-01

202

Novel modes of mechanical ventilation.  

PubMed

The overarching goal of positive pressure mechanical ventilation is to provide adequate gas exchange support while not causing harm. Indeed, positive pressure mechanical ventilators are only support technologies, not therapeutic technologies. As such they cannot be expected to "cure" disease; they can only "buy time" for other therapies (including the patient's own defenses) to work.Conventional approaches to positive pressure ventilation involve applying ventilatory patterns mimicking normal ones through either masks or artificial airways. This is usually done with modes of support incorporating assist/control breath-triggering mechanisms, gas delivery patterns governed by either a set flow or pressure, and breath cycling based on either a set volume, a set inspiratory time, or a set flow. Often this support includes positive end-expiratory pressure and supplemental oxygen. In recent decades several novel or unconventional approaches to providing mechanical ventilatory support have been introduced. For these to be considered of value, however, it would seem reasonable that they address important clinical challenges and be shown to improve important clinical outcomes (e.g., mortality, duration of ventilation, sedation needs, complications). This article focuses on challenges facing clinicians in providing mechanical ventilatory support and assesses several novel approaches introduced over the last 2 decades in the context of these challenges. PMID:23934718

Al-Hegelan, Mashael; MacIntyre, Neil R

2013-08-11

203

Artificial ventilation in severe pertussis  

Microsoft Academic Search

A retrospective review was conducted of all children admitted to our intensive care unit over eight years with a diagnosis of pertussis that had been proved on culture. Altogether 789 children were seen as outpatients and inpatients. Twenty four of these children were admitted to the intensive care unit, 13 of whom required ventilatory support; two of the ventilated patients

J Gillis; T Grattan-Smith; H Kilham

1988-01-01

204

To ventilate, oscillate, or cannulate?  

PubMed

Ventilatory management of acute respiratory distress syndrome has evolved significantly in the last few decades. The aims have shifted from optimal gas transfer without concern for iatrogenic risks to adequate gas transfer while minimizing lung injury. This change in focus, along with improved ventilator and multiorgan system management, has resulted in a significant improvement in patient outcomes. Despite this, a number of patients develop hypoxemic respiratory failure refractory to lung-protective ventilation (LPV). The intensivist then faces the dilemma of either persisting with LPV using adjuncts (neuromuscular blocking agents, prone positioning, recruitment maneuvers, inhaled nitric oxide, inhaled prostacyclin, steroids, and surfactant) or making a transition to rescue therapies such as high-frequency oscillatory ventilation (HFOV) and/or extracorporeal membrane oxygenation (ECMO) when both these modalities are at their disposal. The lack of quality evidence and potential harm reported in recent studies question the use of HFOV as a routine rescue option. Based on current literature, the role for venovenous (VV) ECMO is probably sequential as a salvage therapy to ensure ultraprotective ventilation in selected young patients with potentially reversible respiratory failure who fail LPV despite neuromuscular paralysis and prone ventilation. Given the risk profile and the economic impact, future research should identify the patients who benefit most from VV ECMO. These choices may be further influenced by the emerging novel extracorporeal carbon dioxide removal devices that can compliment LPV. Given the heterogeneity of acute respiratory distress syndrome, each of these modalities may play a role in an individual patient. Future studies comparing LPV, HFOV, and VV ECMO should not only focus on defining the patients who benefit most from each of these therapies but also consider long-term functional outcomes. PMID:23827735

Shekar, Kiran; Davies, Andrew R; Mullany, Daniel V; Tiruvoipati, Ravindranath; Fraser, John F

2013-07-02

205

The ``Temperature Amplifier'': an Innovative Application of Pressure-Controlled Heat-Pipes for Calibration of PRTs and Thermocouples  

NASA Astrophysics Data System (ADS)

At high temperature (from 600 °C to 962 °C) calibration by comparison of platinum resistance thermometers (PRTs) is limited by the instability and the reliability of the standard high-temperature PRT and by the temperature uniformity in the working volume of furnaces equipped with comparison blocks. To improve its calibration-comparison capability, BNM-INM is studying the possibility of connecting several pressure-controlled heat-pipes, filled with different working fluids, simultaneously to the same pressure control system. The experimental apparatus, called a ``temperature amplifier,'' is composed of three heat-pipes filled with sodium (Na), potassium (K), and dodecane (Do).

Renaot, E.; Elgourdou, M.; Bonnier, G.

2003-09-01

206

Experimental research on charging characteristics of a pressure-controlled VRLA battery in high-temperature environments  

Microsoft Academic Search

Valve-regulated-lead-acid (VRLA) battery charging performed in high-temperature environments is extremely risky under overcharge\\u000a conditions, and may lead to a subsequent thermal runaway. A new pressure-controlled charging method was adopted and the charging\\u000a characteristics of the pressure-controlled VRLA battery in high-temperature environments were experimentally studied. The\\u000a concept was tested in a large temperature gradient to obtain more details about the effects

Hua Zhu; Jin-jun Tan; Zhang-lu Xu; Ji-sen Xu

2009-01-01

207

Constant pressure-controlled extrusion method for the preparation of Nano-sized lipid vesicles.  

PubMed

Liposomes are artificially prepared vesicles consisting of natural and synthetic phospholipids that are widely used as a cell membrane mimicking platform to study protein-protein and protein-lipid interactions, monitor drug delivery, and encapsulation. Phospholipids naturally create curved lipid bilayers, distinguishing itself from a micelle. Liposomes are traditionally classified by size and number of bilayers, i.e. large unilamellar vesicles (LUVs), small unilamellar vesicles (SUVs) and multilamellar vesicles (MLVs). In particular, the preparation of homogeneous liposomes of various sizes is important for studying membrane curvature that plays a vital role in cell signaling, endo- and exocytosis, membrane fusion, and protein trafficking. Several groups analyze how proteins are used to modulate processes that involve membrane curvature and thus prepare liposomes of diameters <100 - 400 nm to study their behavior on cell functions. Others focus on liposome-drug encapsulation, studying liposomes as vehicles to carry and deliver a drug of interest. Drug encapsulation can be achieved as reported during liposome formation. Our extrusion step should not affect the encapsulated drug for two reasons, i.e. (1) drug encapsulation should be achieved prior to this step and liposomes should retain their natural biophysical stability, securely carrying the drug in the aqueous core. These research goals further suggest the need for an optimized method to design stable sub-micron lipid vesicles. Nonetheless, the current liposome preparation technologies (sonication, freeze-and-thaw, sedimentation) do not allow preparation of liposomes with highly curved surface (i.e. diameter <100 nm) with high consistency and efficiency, which limits the biophysical studies of an emerging field of membrane curvature sensing. Herein, we present a robust preparation method for a variety of biologically relevant liposomes. Manual extrusion using gas-tight syringes and polycarbonate membranes, is a common practice but heterogeneity is often observed when using pore sizes <100 nm due to due to variability of manual pressure applied. We employed a constant pressure-controlled extrusion apparatus to prepare synthetic liposomes whose diameters range between 30 and 400 nm. Dynamic light scattering (DLS), electron microscopy and nanoparticle tracking analysis (NTA) were used to quantify the liposome sizes as described in our protocol, with commercial polystyrene (PS) beads used as a calibration standard. A near linear correlation was observed between the employed pore sizes and the experimentally determined liposomes, indicating high fidelity of our pressure-controlled liposome preparation method. Further, we have shown that this lipid vesicle preparation method is generally applicable, independent of various liposome sizes. Lastly, we have also demonstrated in a time course study that these prepared liposomes were stable for up to 16 hours. A representative nano-sized liposome preparation protocol is demonstrated below. PMID:22760481

Morton, Leslie A; Saludes, Jonel P; Yin, Hang

2012-06-22

208

Clinical review: Liberation from mechanical ventilation  

PubMed Central

Mechanical ventilation is the defining event of intensive care unit (ICU) management. Although it is a life saving intervention in patients with acute respiratory failure and other disease entities, a major goal of critical care clinicians should be to liberate patients from mechanical ventilation as early as possible to avoid the multitude of complications and risks associated with prolonged unnecessary mechanical ventilation, including ventilator induced lung injury, ventilator associated pneumonia, increased length of ICU and hospital stay, and increased cost of care delivery. This review highlights the recent developments in assessing and testing for readiness of liberation from mechanical ventilation, the etiology of weaning failure, the value of weaning protocols, and a simple practical approach for liberation from mechanical ventilation.

El-Khatib, Mohamad F; Bou-Khalil, Pierre

2008-01-01

209

Multi-bottle, no compressor, mean pressure control system for a Stirling engine  

SciTech Connect

The invention relates to an apparatus for mean pressure control of a Stirling engine without the need for a compressor. The invention includes a multi-tank system in which there is at least one high pressure level tank and one low pressure level tank wherein gas flows through a maximum pressure and supply line from the engine to the high pressure tank when a first valve is opened until the maximum pressure of the engine drops below that of the high pressure tank opening an inlet regulator to permit gas flow from the engine to the low pressure tank. When gas flows toward the engine it flows through the minimum pressure supply line 2 when a second valve is opened from the low pressure tank until the tank reaches the engine's minimum pressure level at which time the outlet regulator opens permitting gas to be supplied from the high pressure tank to the engine. Check valves between the two tanks prevent any backflow of gas from occurring.

Corey, John A. (Melrose, NY)

1990-01-01

210

Ventless pressure control of two-phase propellant tanks in microgravity.  

PubMed

This work studies pressurization and pressure control of a large liquid hydrogen storage tank. A finite element model is developed that couples a lumped thermodynamic formulation for the vapor region with a complete solution of the Navier-Stokes and energy equations for the flow and temperature fields in the liquid. Numerical results show that buoyancy effects are strong, even in microgravity, and can reposition a vapor bubble that is initially at the center of the tank to a region near the tank wall in a relatively short time. Long-term tank pressurization with the vapor bubble at the tank wall shows that after an initial transient lasting about a week, the final rate of pressure increase agrees with a purely thermodynamic analysis of the entire tank. However, the final pressure levels are quite different from thermodynamic predictions. Numerical results also show that there is significant thermal stratification in the liquid due to the effects of natural convection. A subcooled jet is used to provide simultaneous cooling and mixing in order to bring the tank pressure back down to its initial value. Three different jet speeds are examined. Although the lowest jet speed is ineffective at controlling the pressure because of insufficient penetration into the liquid region, the highest jet speed is shown to be quite effective at disrupting thermal stratification and reducing the tank pressure in reasonable time. PMID:15644378

Kassemi, Mohammad; Panzarella, Charles H

2004-11-01

211

Summary of human responses to ventilation  

SciTech Connect

The effects of ventilation on indoor air quality and health is a complex issue. It is known that ventilation is necessary to remove indoor generated pollutants from indoor air or dilute their concentration to acceptable levels. But, as the limit values of all pollutants are not known, the exact determination of required ventilation rates based on pollutant concentrations and associated risks is seldom possible. The selection of ventilation rates has to be based also on epidemiological research (e.g. Seppanen et al., 1999), laboratory and field experiments (e.g. CEN 1996, Wargocki et al., 2002a) and experience (e.g. ECA 2003). Ventilation may also have harmful effects on indoor air quality and climate if not properly designed, installed, maintained and operated as summarized by Seppdnen (2003). Ventilation may bring indoors harmful substances that deteriorate the indoor environment. Ventilation also affects air and moisture flow through the building envelope and may lead to moisture problems that deteriorate the structures of the building. Ventilation changes the pressure differences over the structures of building and may cause or prevent the infiltration of pollutants from structures or adjacent spaces. Ventilation is also in many cases used to control the thermal environment or humidity in buildings. Ventilation can be implemented with various methods which may also affect health (e.g. Seppdnen and Fisk, 2002, Wargocki et al., 2002a). In non residential buildings and hot climates, ventilation is often integrated with air-conditioning which makes the operation of ventilation system more complex. As ventilation is used for many purposes its health effects are also various and complex. This paper summarizes the current knowledge on positive and negative effects of ventilation on health and other human responses. The focus of the paper is on office-type working environment and residential buildings. In the industrial premises the problems of air quality are usually more complex and case specific. They are subject to occupational safety legislation and not discussed here.

Seppanen, Olli A.; Fisk, William J.

2004-06-01

212

Arterial pressure control during non-hypo\\/hypertensive changes in central venous volume: assessment with multivariate autoregressive modeling  

Microsoft Academic Search

To evaluate how small decreases and increases of central volume influence heart rate and arterial pressure control multivariate autoregressive techniques were used to quantify the interactions between respiration, RR interval and arterial blood pressure during random interval breathing, at 3 low levels of lower body negative pressure and 3 low levels of increased central volume. In addition to the classic

R. Barbieri; J. K. Triedman; V. Di Virgilio; S. Cerutti; J. P. Saul

1996-01-01

213

[Noninvasive ventilation in intensive care].  

PubMed

Non-invasive ventilation has been in use for many years to provide long-term home ventilatory support to patients with chronic respiratory failure. In recent years, it has emerged on the intensive care scene as a means of avoiding intubation in acute respiratory failure. The results of several studies indicate that such an approach can lead to a reduction in mortality and duration of hospital stay compared to conventional mechanical ventilation with endotracheal intubation. The purpose of this article is to explore the various ventilatory techniques available, the choice of respirator and ventilatory mode in various clinical conditions, and to discuss some of the logistics involved in the optimal use of this technique. PMID:9064754

Jolliet, P; Sommer-Buhler, J; Abajo, B; Chevrolet, J C

1997-01-25

214

Difficult weaning from mechanical ventilation  

Microsoft Academic Search

Difficult weaning is fortunately a rare occurrence in mechanically ventilated patients in ICU. When faced with this problem,\\u000a a vast number of factors must be carefully considered simultaneously: physiological adjustment, technical problems (tubing,\\u000a circuit resistances, ...) [13]. The most promising approach to difficult weaning to date centers on the respiratory muscle\\u000a function which represents the most common factor allowing weaning

J. C. Chevrolet

1990-01-01

215

Development of a Residential Integrated Ventilation Controller  

SciTech Connect

The goal of this study was to develop a Residential Integrated Ventilation Controller (RIVEC) to reduce the energy impact of required mechanical ventilation by 20percent, maintain or improve indoor air quality and provide demand response benefits. This represents potential energy savings of about 140 GWh of electricity and 83 million therms of natural gas as well as proportional peak savings in California. The RIVEC controller is intended to meet the 2008 Title 24 requirements for residential ventilation as well as taking into account the issues of outdoor conditions, other ventilation devices (including economizers), peak demand concerns and occupant preferences. The controller is designed to manage all the residential ventilation systems that are currently available. A key innovation in this controller is the ability to implement the concept of efficacy and intermittent ventilation which allows time shifting of ventilation. Using this approach ventilation can be shifted away from times of high cost or high outdoor pollution towards times when it is cheaper and more effective. Simulations, based on the ones used to develop the new residential ventilation requirements for the California Buildings Energy code, were used to further define the specific criteria and strategies needed for the controller. These simulations provide estimates of the energy, peak power and contaminant improvement possible for different California climates for the various ventilation systems. Results from a field test of the prototype controller corroborate the predicted performance.

Staff Scientist; Walker, Iain; Sherman, Max; Dickerhoff, Darryl

2011-12-01

216

Passive ventilation for residential air quality control  

SciTech Connect

Infiltration has long served the residential ventilation needs in North America. In Northern Europe it has been augmented by purpose-provided natural ventilation systems--so-called passive ventilation systems--to better control moisture problems in dwellings smaller than their North American counterparts and in a generally wetter climate. The growing concern for energy consumption, and the environmental impacts associated with it, has however led to tighter residential construction standards on both continents and as a result problems associated with insufficient background ventilation have surfaced. Can European passive ventilation systems be adapted for use in North American dwellings to provide general background ventilation for air quality control? This paper attempts to answer this question. The configuration, specifications and performance of the preferred European passive ventilation system--the passive stack ventilation (PSV) system--will be reviewed; innovative components and system design strategies recently developed to improve the traditional PSV system performance will be outlined; and alternative system configurations will be presented that may better serve the climatic extremes and more urban contexts of North America. While these innovative and alternative passive ventilation systems hold great promise for the future, a rational method to size the components of these systems to achieve the control and precision needed to meet the conflicting constraints of new ventilation and air tightness standards has not been forthcoming. Such a method will be introduced in this paper and an application of this method will be presented.

Axley, J.

1999-07-01

217

Particle deposition in ventilation ducts  

SciTech Connect

Exposure to airborne particles is detrimental to human health and indoor exposures dominate total exposures for most people. The accidental or intentional release of aerosolized chemical and biological agents within or near a building can lead to exposures of building occupants to hazardous agents and costly building remediation. Particle deposition in heating, ventilation and air-conditioning (HVAC) systems may significantly influence exposures to particles indoors, diminish HVAC performance and lead to secondary pollutant release within buildings. This dissertation advances the understanding of particle behavior in HVAC systems and the fates of indoor particles by means of experiments and modeling. Laboratory experiments were conducted to quantify particle deposition rates in horizontal ventilation ducts using real HVAC materials. Particle deposition experiments were conducted in steel and internally insulated ducts at air speeds typically found in ventilation ducts, 2-9 m/s. Behaviors of monodisperse particles with diameters in the size range 1-16 {micro}m were investigated. Deposition rates were measured in straight ducts with a fully developed turbulent flow profile, straight ducts with a developing turbulent flow profile, in duct bends and at S-connector pieces located at duct junctions. In straight ducts with fully developed turbulence, experiments showed deposition rates to be highest at duct floors, intermediate at duct walls, and lowest at duct ceilings. Deposition rates to a given surface increased with an increase in particle size or air speed. Deposition was much higher in internally insulated ducts than in uninsulated steel ducts. In most cases, deposition in straight ducts with developing turbulence, in duct bends and at S-connectors at duct junctions was higher than in straight ducts with fully developed turbulence. Measured deposition rates were generally higher than predicted by published models. A model incorporating empirical equations based on the experimental measurements was applied to evaluate particle losses in supply and return duct runs. Model results suggest that duct losses are negligible for particle sizes less than 1 {micro}m and complete for particle sizes greater than 50 {micro}m. Deposition to insulated ducts, horizontal duct floors and bends are predicted to control losses in duct systems. When combined with models for HVAC filtration and deposition to indoor surfaces to predict the ultimate fates of particles within buildings, these results suggest that ventilation ducts play only a small role in determining indoor particle concentrations, especially when HVAC filtration is present. However, the measured and modeled particle deposition rates are expected to be important for ventilation system contamination.

Sippola, Mark R.

2002-09-01

218

Improved OCT imaging of lung tissue using a prototype for total liquid ventilation  

NASA Astrophysics Data System (ADS)

Optical coherence tomography (OCT) is used for imaging subpleural alveoli in animal models to gain information about dynamic and morphological changes of lung tissue during mechanical ventilation. The quality of OCT images can be increased if the refraction index inside the alveoli is matched to the one of tissue via liquid-filling. Thereby, scattering loss can be decreased and higher penetration depth and tissue contrast can be achieved. Until now, images of liquid-filled lungs were acquired in isolated and fixated lungs only, so that an in vivo measurement situation is not present. To use the advantages of liquid-filling for in vivo imaging of small rodent lungs, it was necessary to develop a liquid ventilator. Perfluorodecalin, a perfluorocarbon, was selected as breathing fluid because of its refraction index being similar to the one of water and the high transport capacity for carbon dioxide and oxygen. The setup is characterized by two independent syringe pumps to insert and withdraw the fluid into and from the lung and a custom-made control program for volume- or pressure-controlled ventilation modes. The presented results demonstrate the liquid-filling verified by optical coherence tomography and intravital microscopy (IVM) and the advantages of liquid-filling to OCT imaging of subpleural alveoli.

Schnabel, Christian; Meissner, Sven; Koch, Edmund

2011-06-01

219

[Lung damage due to mechanical ventilation].  

PubMed

Mechanical ventilation in both children and adults is still associated with development of lung injury, both short term and long term. In particular, ventilation with high tidal volumes and low positive end-expiratory pressures (PEEP) contributes significantly to development of lung injury. Suggested preventive measures consist of limiting peak inflation pressures, preventing high tidal volumes, and applying high PEEP to prevent alveolar collapse. Recent studies have demonstrated that mechanical ventilation, via stretch of lung tissue, results in an inflammatory reaction in the lungs. This is known as biotrauma. The degree of inflammation depends on the ventilator settings and mode of ventilation. This inflammatory reaction may not be limited to the lungs but, via inflammatory mediators, may cause multiple organ dysfunction as well. Future research needs to be concentrated on how to modify this ventilator induced inflammatory reaction in order to prevent lung injury as well as systemic injury. PMID:10086125

Plötz, F B; van Vught, A J

1999-01-16

220

Injurious mechanical ventilation affects neuronal activation in ventilated rats  

Microsoft Academic Search

Introduction  Survivors of critical illness often have significant long-term brain dysfunction, and routine clinical procedures like mechanical\\u000a ventilation (MV) may affect long-term brain outcome. We aimed to investigate the effect of the increase of tidal volume (Vt)\\u000a on brain activation in a rat model.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Male Sprague Dawley rats were randomized to three groups: 1) Basal: anesthetized unventilated animals, 2) low Vt

Elisa María Quilez; Gemma Fuster; Jesús Villar; Carlos Flores; Octavi Martí-Sistac; Lluís Blanch; Josefina López-Aguilar

2011-01-01

221

Nontraditional modes of mechanical ventilation: progress or distraction?  

PubMed

As technology continues to develop, a wide range of novel and nontraditional modes of mechanical ventilation have become available for the management of critically ill patients. Proportional assist ventilation, neurally adjusted ventilatory assist and adaptive support ventilation are three novel modes of ventilation, which attempt to optimize patient-ventilator synchrony. Improved interactions between patient and ventilator may be important in improving clinical outcomes. Another important priority for mechanically ventilated patients is lung protection, and nontraditional modes of ventilation that may be implemented to minimize ventilator-associated lung injury include airway pressure release ventilation and high-frequency ventilation. Novel and nontraditional modes of ventilation may represent important tools in the critical care environment; however, continued investigation is needed to determine the overall impact of these various approaches on outcomes for mechanically ventilated patients. PMID:22788942

Turner, David A; Rehder, Kyle J; Cheifetz, Ira M

2012-06-01

222

High-frequency percussive ventilation revisited.  

PubMed

High-frequency percussive ventilation (HFPV) has demonstrated a potential role as a rescue option for refractory acute respiratory distress syndrome and as a method for improving inhalation injury outcomes. Nevertheless, there is a lack of literature examining the practical application of HFPV theory toward either improving gas exchange or preventing possible ventilator-induced lung injury. This article will discuss the clinically pertinent aspects of HFPV, inclusive of high- and low-frequency ventilation. PMID:20616646

Allan, Patrick F; Osborn, Erik C; Chung, Kevin K; Wanek, Sandra M

223

Performance of ventilators for noninvasive positive-pressure ventilation in children  

Microsoft Academic Search

The aim of the present study was to evaluate the performance characteristics of all the ventilators proposed for home noninvasive positive-pressure ventilation in children in France. The ventilators (one volume-targeted, 12 pressure-targeted and four dual) were evaluated on a bench which simulated six different paediatric ventilatory patterns. For each ventilator, the quality of the inspiratory and expiratory trigger and the

B. Fauroux; K. Leroux; G. Desmarais; D. Isabey; A. Clement; F. Lofaso; B. Louis

2008-01-01

224

Ventilator-induced respiratory muscle weakness  

PubMed Central

Clinicians have long been aware that substantial lung injury results when mechanical ventilation imposes too much stress on the pulmonary parenchyma. Evidence is accruing that substantial injury may also result when the ventilator imposes too little stress on the respiratory muscles. Through adjustment of ventilator settings and administration of pharmacotherapy it is possible to render the respiratory muscles almost (or completely) inactive. Research in animals has shown that diaphragmatic inactivity produces severe injury and atrophy of muscle fibers. Human data have recently revealed that 18 to 69 hours of complete diaphragmatic inactivity associated with mechanical ventilation decreased the cross-sectional areas of diaphragmatic fibers by half or more. The atrophic injury appears to result from increased oxidative stress leading to activation of protein-degradation pathways. Scientific understanding of ventilator-induced respiratory muscle injury has not reached the stage where it is possible to undertake meaningful controlled trials and thus it is not possible to render concrete recommendations for patient management. In the meantime, clinicians are advised to select ventilator settings that avoid both excessive patient effort and also excessive respiratory muscle rest. The contour of the airway pressure waveform on a ventilator screen provides the most practical indication of patient effort, and clinicians are advised to pay close attention to the waveform as they titrate ventilator settings. Research on ventilator-induced respiratory muscle injury is in its infancy and portends to be an exciting area to follow.

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

2010-01-01

225

Elective high frequency oscillatory ventilation versus conventional ventilation for acute pulmonary dysfunction in preterm infants  

Microsoft Academic Search

Background Respiratory failure due to lung immaturity is a major cause of mortality in preterm infants. Although the use of intermittent positive pressure ventilation (IPPV) in neonates with respiratory failure saves lives, its use is associated with lung injury and chronic lung disease (CLD). A newer form of ventilation called high frequency oscillatory ventilation (HFOV) has been shown to result

F. Cools; D. J. Henderson-Smart; M. Offringa; L. M. Askie

2009-01-01

226

[Home mechanical ventilation-tracheostomy ventilation, for the long-term and variation].  

PubMed

We experienced long-term ventilation for 30 patients mostly with amyotrophic lateral sclerosis (ALS). For long-term ventilation by tracheostomy positive pressure ventilation (TPPV), we must set tidal volume (TV) over 600 ml, because setting 400 ml as TV usually applied in Japan, often develops atelectasis which causes frequent or serious pneumonia. To avoid both the elevation of airway pressure and hyper ventilation, the following intervals are needed: 10 times/min for breathing frequency and 2 seconds for exhaling time. In the cases with ventilator induced lung injury (VILI), it is necessary to lower the TV and to treat with steroid pulse therapy. In the transitional stage from non-invasive positive pressure ventilation (NPPV) to TPPV, we conduct tracheostomy for suction of the sputum. In that stage, by using a cuffless tracheal canule, we can continue NPPV. As another method in that stage, we recommend biphasic management by NPPV at daytime and TPPV at nighttime with a bi-level ventilator. This method can provide certain ventilation also during sleep. When the respiratory failure proceeds further, we manage the ventilation with a bi-level ventilator on TPPV, because a bi-level ventilator is also good adapting to assist spontaneous breathing in that stage. And if the patient does not have bulbar paralysis, the patient can utter by air leakage with using bi-level ventilator and flattening the cuff of the tracheal canule. PMID:17469348

Yamamoto, Makoto

2006-12-01

227

Global temperature field simulation of the vapour pressure controlled Czochralski (VCZ) growth of 3?–4? gallium arsenide crystals  

Microsoft Academic Search

The vapour pressure controlled Czochralski (VCZ) method belongs to the new methods to provide low-gradient temperature fields during the growth of III–V crystals. For the first time a global two-dimensional model of the VCZ growth of 3? and 4? GaAs crystals is presented. The finite volume code CrysVUN++ was used to simulate heat transfer taking into account conduction and radiation

K. Bottcher; P Rudolph; M Neubert; M Kurz; A Pusztai; G Müller

1999-01-01

228

Effects of aggressive blood pressure control in normotensive type 2 diabetic patients on albuminuria, retinopathy and strokes  

Microsoft Academic Search

Effects of aggressive blood pressure control in normotensive type 2 diabetic patients on albuminuria, retinopathy and strokes.BackgroundAlthough several important studies have been performed in hypertensive type 2 diabetic patients, it is not known whether lowering blood pressure in normotensive (BP <140\\/90 mm Hg) patients offers any beneficial results on vascular complications. The current study evaluated the effect of intensive versus

Robert W. Schrier; Raymond O. Estacio; Anne Esler; Philip Mehler

2002-01-01

229

The Role of Religion in Relation to Blood Pressure Control Among a Southern California Thai Population with Hypertension  

Microsoft Academic Search

This qualitative research investigates the role religion plays in relation to blood pressure control among a Southern California\\u000a Thai population with hypertension. A total of 15 Thai individuals between the ages of 45–95 were interviewed. All participants\\u000a indicated that stress plays a significant role in determining their ability to manage hypertension. Of the 15 participants,\\u000a 14 acknowledged that religion plays

Supaporn Naewbood; Siroj Sorajjakool; Somporn Kantharadussadee Triamchaisri

230

46 CFR 185.352 - Ventilation of gasoline machinery spaces.  

Code of Federal Regulations, 2011 CFR

... Ventilation of gasoline machinery spaces. 185.352 Section 185.352 ...Ventilation of gasoline machinery spaces. The mechanical exhaust for the ventilation of a gasoline machinery space, required by §...

2011-10-01

231

46 CFR 154.1205 - Mechanical ventilation system: Standards.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Mechanical ventilation system: Standards. 154...Construction and Equipment Cargo Area: Mechanical Ventilation System § 154.1205 Mechanical ventilation system: Standards....

2010-10-01

232

46 CFR 92.15-10 - Ventilation for closed spaces.  

Code of Federal Regulations, 2010 CFR

... 2009-10-01 2009-10-01 false Ventilation for closed spaces. 92.15-10 Section...MISCELLANEOUS VESSELS CONSTRUCTION AND ARRANGEMENT Ventilation § 92.15-10 Ventilation for closed spaces. (a) Except...

2009-10-01

233

Mechanical Ventilation and the Kidney  

PubMed Central

Acute lung injury (ALI) and acute kidney injury (AKI) are complications often encountered in the setting of critical illness. Both forms of end-organ injury commonly occur in similar settings of systemic inflammatory response syndrome, shock, and evolving multiple organ dysfunction. Recent elucidation of the pathobiology of critical illness has led to a more basic mechanistic understanding of the complex interplay between injured organs in patients with multiple organ dysfunction syndrome; this has been aptly called ‘the slippery slope of critical illness’ [Kidney Int Suppl 1998;66:S25–S33]. Distant organ effects of apparently isolated injuries to the lungs, gut, and kidneys have all been discovered in recent years. In this article, we will review the harmful bidirectional interaction between ALI and AKI, which appears to be a common clinical syndrome with routine clinical implications. We will review the current understanding of lung-kidney interactions from both perspectives, including the renal effects of ALI and mechanical ventilation, and the pulmonary sequelae of AKI. In this review of the emerging evidence of deleterious bidirectional organ cross talk between lung and kidney, we will focus on the role of ventilator-induced kidney injury in the pathogenesis of AKI in patients with ALI.

Koyner, Jay L.; Murray, Patrick T.

2010-01-01

234

Dynamic Behaviour of Ventilated Hydrofoils.  

NASA Astrophysics Data System (ADS)

In certain types of pumping applications oscillations are induced by operation with liquids containing a free gas load. In order to understand the physics of this process, a series of tests with a ventilated A 2D NACA 0015 hydrofoil were performed in the water tunnel at the St. Anthony Falls Laboratory of the University of Minnesota. The special bubble removal feature of the water tunnel allowed continuous ventilation without experiencing visible bubbles upstream the hydrofoil. These studies build on previous work on cavitation-induced oscillations. Gas injection studies were made over a range of gas flow rates and test section pressure. The results clearly show that lift oscillations increase in intensity when the gas load is increased. The point of maximum unsteadiness is also associated the rapid decline of the foil performance as measured as average lift. Further increase of the gas injection load gives a steady behaviour with almost no lift. These experiments are compared with traditional cavitation experiments. The similarities between gas injection- and cavitation induced unsteadiness on the hydrofoil are many, but the amplitude of lift oscillations found on the foil with gas injection corresponds to about 50% of that found for cavitating hydrofoils. The fact that the oscillations are periodic leads to the consideration of both passive and active control.

Kjeldsen, Morten; Arndt, Roger; Wosnik, Martin

2006-11-01

235

Increasing energy efficiency of mine ventilation systems  

SciTech Connect

Every year the US mining industry spends millions of dollars on underground ventilation systems. Potential motor-driven system energy savings can be realized by using mature, proven, and cost-effective technologies. Improved energy efficiency also leads to reduced environmental emissions. This paper promotes a systems approach to increase the energy efficiency in mine ventilation.

Papar, Riyaz; Szady, A.; Huffer, W.D.; Martin V.; McKane, A.T.

1999-06-01

236

Daytime mechanical ventilation in chronic respiratory insufficiency  

Microsoft Academic Search

Chronic respiratory insufficiency (CRI) is associated with nocturnal hypoventilation. Treatment with noninvasive mechanical ventilation (NIMV) per- formed overnight relieves symptoms of hypoventilation and improves daytime blood gases in CRI. In order to test whether the efficacy of NIMV depends on it being applied during sleep, we conducted a prospective case-controlled study comparing daytime mechanical ventilation (dMV) in awake patients with

B. Schönhofer; M. Geibel; M. Sonneborn; P. Haidl; D. Köhler

1997-01-01

237

Tracheostomy and home ventilation in children  

Microsoft Academic Search

The last 30 years have brought a significant emphasis on home care for ventilator-dependent children. While the movement was driven by the desire to minimize healthcare costs, the advancements in medical knowledge and technology, and the change in the perception of a ventilator-dependent child have offered a fertile environment for the development of programs that support the chronic care of

Raouf S. Amin; Cynthia M. Fitton

2003-01-01

238

Noninvasive Ventilation for Acute Respiratory Failure  

Microsoft Academic Search

Noninvasive ventilation for acute respiratory failure. L. Brochard, J. Mancebo, M.W. Elliott. #ERS Journals Ltd 2002. ABSTRACT: Noninvasive ventilation (NIV) has emerged as a significant advance in the management of respiratory failure. There is now a wide body of prospective randomized-controlled trial data to support its use, particularly in the management of patients with acute or respiratory failure due to

L. Brochard; J. Mancebo; M. W. Elliott

2002-01-01

239

Ventilation abnormalities associated with pulmonary embolism  

SciTech Connect

A retrospective analysis of 2035 lung images performed over approximately 5 years revealed abnormal ventilation coexisting with pulmonary embolism in 18 patients. Matching ventilation perfusion defects may be associated with pulmonary embolism without infarction. In patients with a high clinical suspicion of acute pulmonary embolism and matching V/Q abnormalities, an angiogram may be necessary to definitely exclude the diagnosis.

Sandler, M.S.; Velchik, M.G.; Alavi, A.

1988-06-01

240

Survey of ventilation rates in office buildings  

Microsoft Academic Search

Building ventilation is a primary determinant of indoor air quality in buildings as it impacts indoor contaminant concentrations and occupant comfort. However, relatively few measurements of office building ventilation performance have been conducted, and those data that exist generally have not employed consistent measurement methods and have not involved representative collections of buildings. The US Environmental Protection Agency (EPA) Building

Andrew K. Persily; Josh Gorfain; Greg Brunner

2006-01-01

241

Liquid ventilation attenuates pulmonary oxidative damage  

Microsoft Academic Search

Purpose: Liquid perfluorochemicals reduce the production of reaction oxygen species by alveolar macrophages. We sought to determine whether the use of liquid perfluorochemicals in vivo during liquid ventilation would attenuate oxidative damage to the lung.Materials and Methods: Healthy infant piglets (n = 16) were instrumented for mechanical ventilation and received intravenous oleic acid to create an acute lung injury. The

David M. Steinhorn; Michele C. Papo; Alexandre T. Rotta; Ahmed Aljada; Bradley P. Fuhrman; Paresh Dandona

1999-01-01

242

Control of resting ventilation rate in grasshoppers  

PubMed

We examined the effect of extracellular acid-base status and tracheal gas levels on the ventilation rate of resting Romalea guttata and Schistocerca americana grasshoppers. We manipulated haemolymph pH and [HCO3-] within normal physiological ranges using injections of HCl, NaOH, NaHCO3 and NaCl into the haemocoel. In contrast to terrestrial vertebrates, there was no evidence that extracellular acidification increases ventilation rate in grasshoppers. Elevation of haemolymph bicarbonate levels (by NaHCO3 injection) increased ventilation rate, while depression of haemolymph bicarbonate levels (HCl injection) had no effect. Injection of NaHCO3 also increased tracheal PCO2, suggesting that the effect of the NaHCO3 injection might be mediated by a sensitivity of the ventilatory system to tracheal gases. We tested for effects of tracheal gases on ventilation rate by independently manipulating tracheal PCO2 and PO2 using tracheal perfusions. Ventilation rate was positively correlated with tracheal PCO2 and negatively correlated with tracheal PO2. Increasing tracheal PO2 above normal resting levels or decreasing tracheal PCO2 below normal levels decreased ventilation rate. We conclude that quiescent grasshoppers regulate tracheal PCO2 and PO2 by varying ventilation rate and that both PCO2 and PO2 in the trachea stimulate ventilation in normal, resting grasshoppers. PMID:9317989

Gulinson; Harrison

1996-01-01

243

Commissioning Ventilated Containment Systems in the Laboratory  

SciTech Connect

This Best Practices Guide focuses on the specialized approaches required for ventilated containment systems, understood to be all components that drive and control ventilated enclosures and local exhaust systems within the laboratory. Geared toward architects, engineers, and facility managers, this guide provides information about technologies and practices to use in designing, constructing, and operating operating safe, sustainable, high-performance laboratories.

Not Available

2008-08-01

244

Performance of Ventilation Systems in Residential Buildings.  

National Technical Information Service (NTIS)

The aim of the study was to gather information on the performance of ventilation systems in residential buildings. The effect of the ventilation on health, comfort and satisfaction was also studied. Data was also collected of the fullfilment of National B...

R. Roennberg R. Ruotsalainen A. Majanen

1989-01-01

245

NUMERICAL EVALUATION OF HYBRID VENTILATION CONTROL STRATEGIES  

Microsoft Academic Search

This paper deals with the development and the evaluation of hybrid ventilation control strategies, using both natural and mechanical modes, in residential buildings using a graphical simulation tool. The description of a library of airflow components and macroscopic pollutants models used to simulate the demand controlled ventilation based on indoor pollutant concentrations is provided. The paper discusses the issue of

David Jreijiry; Ahmad Husaunndee; Christian Inard

2005-01-01

246

Infiltration in ASHRAE's Residential Ventilation Standards  

SciTech Connect

The purpose of ventilation is to dilute or remove indoor contaminants that an occupant could be exposed to. It can be provided by mechanical or natural means. ASHRAE Standards including standards 62, 119, and 136 have all considered the contribution of infiltration in various ways, using methods and data from 20 years ago. The vast majority of homes in the United States and indeed the world are ventilated through natural means such as infiltration caused by air leakage. Newer homes in the western world are tight and require mechanical ventilation. As we seek to provide acceptable indoor air quality at minimum energy cost, it is important to neither over-ventilate norunder-ventilate. Thus, it becomes critically important to correctly evaluate the contribution infiltration makes to both energy consumption and equivalent ventilation. ASHRAE Standard 62.2 specifies how much mechanical ventilation is considered necessary to provide acceptable indoor air quality, but that standard is weak on how infiltration can contribute towards meeting the total requirement. In the past ASHRAE Standard 136 was used to do this, but new theoretical approaches and expanded weather data have made that standard out of date. This article will describe how to properly treat infiltration as an equivalent ventilation approach and then use new data and these new approaches to demonstrate how these calculations might be done both in general and to update Standard 136.

Sherman, Max

2008-10-01

247

YMP Engineered Barrier Systems Scaled Ventilation Testing  

SciTech Connect

Yucca Mountain, approximately 100 miles northwest of Las Vegas, Nevada, has been selected as the site for the nation's first geologic repository for high level nuclear waste. The Yucca Mountain Project (YMP) is currently developing the design for the underground facilities. Ventilation is a key component of the design as a way to maintain the desired thermal conditions in the emplacement drifts prior to closure. As a means of determining the effects of continuous ventilation on heat removal from the emplacement drifts two series of scaled ventilation tests have been performed. Both test series were performed in the DOE/North Las Vegas Atlas facility. The tests provided scaled (nominally 25% of the full scale emplacement drift design) thermal and flow process data that will be used to validate YMP heat and mass transport codes. The Phase I Ventilation Test series evaluated the ability of ambient ventilation air to remove energy under varying flow and input power conditions. The Phase II Ventilation Test series evaluated the ability of pre-conditioned ventilation air to remove energy under varying flow, input temperature and moisture content, and simulated waste package input power conditions. Twenty-two distinct ventilation tests were run.

S.D. Dunn; B. Lowry; B. Walsh; J.D. Mar; C. Howard; R. Johnston; T. Williams

2002-11-22

248

Thermofluid-dynamic analysis of ventilated facades  

Microsoft Academic Search

Ventilated facades can be used in cases of renovation of existing buildings and new buildings to improve both the thermal performance of building, and external architectural skin. The energy advantage provided by the ventilated facades during the summer is the reduction of the heat load due to the combined effect of the shading of the external wall and the air

F. Patania; A. Gagliano; F. Nocera; A. Ferlito; A. Galesi

2010-01-01

249

Mine ventilation and air conditioning. 3. edition  

SciTech Connect

This revised edition presents an engineering design approach to ventilation and air conditioning as part of the comprehensive environmental control of the mine atmosphere. It provides an in-depth look, for practitioners who design and operate mines, into the health and safety aspects of environmental conditions in the underground workplace. The contents include: Environmental control of the mine atmosphere; Properties and behavior of air; Mine air-quality control; Mine gases; Dusts and other mine aerosols; Mine ventilation; Airflow through mine openings and ducts; Mine ventilation circuits and networks; Natural ventilation; Fan application to mines; Auxiliary ventilation and controlled recirculation; Economics of airflow; Control of mine fires and explosions; Mine air conditioning; Heat sources and effect in mines; Mine air conditioning systems; Appendices; References; Answers to selected problems; and Index.

Hartman, H.L. [Univ. of Alabama, University, AL (United States); Mutmansky, J.M.; Ramani, R.V. [Pennsylvania State Univ., University Park, PA (United States); Wang, Y.J. [West Virginia Univ., Morgantown, WV (United States)

1998-12-31

250

[Non-invasive mechanical ventilation in COPD].  

PubMed

Non-invasive mechanical ventilation is the preferred method for the treatment of acute respiratory failure in patients with chronic obstructive pulmonary disease (COPD). Primary contraindications and stopping criteria must be regarded to avoid delaying endotracheal intubation. The primary interface is usually a nasal-oral mask. Cautious sedation can facilitate non-invasive ventilation in some patients. Under certain circumstances non-invasive ventilation may enable successful extubation in COPD patients with prolonged weaning. COPD patients can also benefit from preventive non-invasive ventilation in order to avoid re-intubation after a planned extubation. Domiciliary nocturnal non-invasive ventilation is an option for some patients with COPD in chronic hypercapnic respiratory failure. This treatment should be established in a specialised unit. PMID:22415450

Funk, G-C

2012-03-15

251

[Lung protective ventilation - pathophysiology and diagnostics].  

PubMed

Mechanical ventilation may lead to lung injury depending on the ventilatory settings (e.g. pressure amplitudes, endexpiratory pressures, frequency) and the length of mechanical ventilation. Particularly in the inhomogeneously injured lungs of ARDS patients, alveolar overextension results in volutrauma, cyclic opening and closure of alveolar units in atelectrauma. Particularly important appears to be the fact that these processes may also cause biotrauma, i.e. the ventilator-induced hyperactivation of inflammatory responses in the lung. These side effects are reduced, but not eliminated with the currently recommended ventilation strategy with a tidal volume of 6 ml/kg idealized body weight. It is our hope that in the future optimization of ventilator settings will be facilated by bedside monitoring of novel indices of respiratory mechanics such as the stress index or the Slice technique, and by innovative real-time imaging technologies such as electrical impedance tomography. PMID:18563672

Uhlig, Stefan; Frerichs, Inéz

2008-06-01

252

[New methods of artificial respiratory ventilation].  

PubMed

High frequency ventilation, a new nonconventional method, has been introduced into clinical practice also in Czechoslovakia, where mainly high frequency jet ventilation (HFJV) is being developed. The HFJ ventilator Best-2 (Konstrukta, Trencín) and Chirajet (Chirana, Stará Turá) which enable HFJV with a multijet generator are used. These equipments reduce inadvertent positive end expiratory pressure by means of an expiration jet and are so designed that Brychta's impulse and expulse regimen can be used to advantage at programmed lavage of the lungs and at selective ventilation of individual parts of the lungs. The paper presents the basic principles of HFJV as well as the author's experience in using this method of ventilation in experimental animals. PMID:2207733

Javorka, K

1990-08-01

253

Implementation of a Hybrid Controller for Ventilation Control Using Soft Computing  

SciTech Connect

Many industrial facilities utilize pressure control gradients to prevent migration of hazardous species from containment areas to occupied zones, often using Proportional-Integral-Derivative (PID) control systems. When operators rebalance the facility, variation from the desired gradients can occur and the operating conditions can change enough that the PID parameters are no longer adequate to maintain a stable system. As the goal of the ventilation control system is to optimize the pressure gradients and associated flows for the facility, Linear Quadratic Tracking (LQT) is a method that provides a time-based approach to guiding facility interactions. However, LQT methods are susceptible to modeling and measurement errors, and therefore the additional use of Soft Computing methods are proposed for implementation to account for these errors and nonlinearities.

Craig G. Rieger; D. Subbaram Naidu

2005-06-01

254

One-Step Multiplex PCR Assay for Detecting Streptococcus pneumoniae Serogroups/Types Covered by 13-Valent Pneumococcal Conjugate Vaccine (PCV13)  

PubMed Central

The life-threatening illnesses caused by Streptococcus pneumoniae have been declined significantly after the use of pneumococcal conjugate vaccines. Continuous monitoring of the vaccine serogroups/types is necessary to follow the changing epidemiology of invasive pneumococcal diseases. Recently, the sequential multiplex PCR approach, which uses several different sets of reactions, has been commonly adopted for determining capsular serogroups/types of S. pneumoniae isolates. In our study, we focused on development of a one-step multiplex PCR assay detecting all 1, 3, 4, 5, 6A/B, 7F, 9V, 14, 18C, 19A, 19F and 23F serogroups/types targeted by PCV13. The content of multiplex PCR mix and the cycling conditions were optimized in a manner that allowed rapid and accurate serotyping of a pneumococcal isolate by performing only a single amplification reaction. In our study of 182 clinical isolates, the one-step multiplex PCR assay exhibited 100% sensitivity and specificity, suggesting that its utilization can significantly reduce the use of traditional antiserum method requiring expensive reagents.

Coskun-Ari, Fatma Filiz; Guldemir, Dilek; Durmaz, Riza

2012-01-01

255

Long-Term Ventilation for High-Level Tetraplegia: A Report of 2 Cases of Noninvasive Positive-Pressure Ventilation  

Microsoft Academic Search

Toki A, Tamura R, Sumida M. Long-term ventilation for high-level tetraplegia: a report of 2 cases of noninvasive positive-pressure ventilation.Ventilator-dependent patients with tetraplegia rarely use noninvasive positive-pressure ventilation (NPPV) for long-term ventilation. We report 2 patients with high-level traumatic tetraplegia who were able to return home after being changed from traditional ventilation to NPPV. When they were referred to our

Akiko Toki; Risa Tamura; Mikio Sumida

2008-01-01

256

Design and Selection of a Camelid Single-Chain Antibody Yeast Two-Hybrid Library Produced De Novo for the Cap Protein of Porcine Circovirus Type 2 (PCV2)  

PubMed Central

Nanobodies (or variable domain of the heavy chain of the heavy-chain antibodies, VHHs) are single-domain antigen-binding fragments derived from camelid heavy chain antibodies. Their comparatively small size, monomeric behavior, high stability, high solubility, and ability to bind epitopes inaccessible to conventional antibodies make them especially suitable for many therapeutic and biotechnological applications. In this paper, for the first time, we created the immunized Camelus Bactrianus VHH yeast two-hybrid (Y2H) library according to the Clontech Mate & Plate library construction system. The transformation efficiency and titer of the VHH Y2H library were 7.26×106 cfu/3 µg and 2×109 cfu/ml, which met the demand for Y2H library screening. Using as an example the porcine circovirus type 2 (PCV2) Cap protein as bait, we screened 21 positive Cap-specific VHH sequences. Among these sequences, 7 of 9 randomly selected clones were strongly positive as indicated by enzyme-linked immunosorbent assay, either using PCV2 viral lysis or purified Cap protein as coated antigen. Additionally, the immunocytochemistry results further indicated that the screened VHHs could specifically detected PCV2 in the infected cells. All this suggests the feasibility of in vivo VHH throughput screening based on Y2H strategy.

Fu, Xiangjing; Gao, Xiaolong; He, Shengfang; Huang, Di; Zhang, Peng; Wang, Xinglong; Zhang, Shuxia; Dang, Ruyi; Yin, Shuanghui; Du, Enqi; Yang, Zengqi

2013-01-01

257

Design and selection of a camelid single-chain antibody yeast two-hybrid library produced de novo for the cap protein of porcine circovirus type 2 (PCV2).  

PubMed

Nanobodies (or variable domain of the heavy chain of the heavy-chain antibodies, VHHs) are single-domain antigen-binding fragments derived from camelid heavy chain antibodies. Their comparatively small size, monomeric behavior, high stability, high solubility, and ability to bind epitopes inaccessible to conventional antibodies make them especially suitable for many therapeutic and biotechnological applications. In this paper, for the first time, we created the immunized Camelus Bactrianus VHH yeast two-hybrid (Y2H) library according to the Clontech Mate & Plate library construction system. The transformation efficiency and titer of the VHH Y2H library were 7.26×10(6) cfu/3 µg and 2×10(9) cfu/ml, which met the demand for Y2H library screening. Using as an example the porcine circovirus type 2 (PCV2) Cap protein as bait, we screened 21 positive Cap-specific VHH sequences. Among these sequences, 7 of 9 randomly selected clones were strongly positive as indicated by enzyme-linked immunosorbent assay, either using PCV2 viral lysis or purified Cap protein as coated antigen. Additionally, the immunocytochemistry results further indicated that the screened VHHs could specifically detected PCV2 in the infected cells. All this suggests the feasibility of in vivo VHH throughput screening based on Y2H strategy. PMID:23469171

Fu, Xiangjing; Gao, Xiaolong; He, Shengfang; Huang, Di; Zhang, Peng; Wang, Xinglong; Zhang, Shuxia; Dang, Ruyi; Yin, Shuanghui; Du, Enqi; Yang, Zengqi

2013-03-01

258

Comparison of prophylactic effects of polyurethane cylindrical or tapered cuff and polyvinyl chloride cuff endotracheal tubes on ventilator-associated pneumonia.  

PubMed

Because microaspiration of contaminated supraglottic secretions past the endotracheal tube cuff is considered to be central in the pathogenesis of pneumonia, improved design of tracheal tubes with new cuff material and shape have reduced the size and number of folds, which together with the addition of suction ports above the cuff to drain pooled subglottic secretions leads to reduced aspiration of oropharyngeal secretions. So we conducted a study to compare the prophylactic effects of polyurethane-cylindrical or tapered cuff and polyvinyl chloride cuff endotracheal tubes (ETT) on ventilator-associated pneumonia. This randomized clinical trial was carried out in a 12 bed surgical intensive care unit. 96 patients expected to require mechanical ventilation more than 96 hours were randomly allocated to one of three following groups: Polyvinyl chloride cuff (PCV) ETT, Polyurethane (PU) cylindrical Sealguard ETT and PU Taperguard ETT. Cuff pressure monitored every three hours 3 days in all patients. Mean cuff pressure didn't have significant difference between three groups during 72 hours. Pneumonia was seen in 11 patients (34%) in group PVC, 8 (25%) in Sealguard and 7 (21%) in Taperguard group. Changes in mean cuff pressure between Sealguard and PVC tubes and also between Taperguard and PVC tubes did not show any significant difference. There was no significant difference in overinflation between three groups. The use of ETT with PU material results in reducing ventilator-associated pneumonia compared to ETT with PVC cuff. In PU tubes Taperguard has less incidence of ventilator-associated pneumonia compared to Sealguard tubes. PMID:23945890

Mahmoodpoor, Ata; Peyrovi-Far, Ali; Hamishehkar, Hadi; Bakhtyiari, Zhaleh; Mirinezhad, Mir Mousa; Hamidi, Masoud; Golzari, Samad Eslam Jamal

2013-08-07

259

Factors Associated with Blood Pressure Control in Hypertensive Patients with Coronary Heart Disease: Evidence from the Chinese Cholesterol Education Program  

PubMed Central

Blood pressure (BP) remains poorly controlled among hypertensive patients with coronary heart disease (CHD) in China. Improvement of its management will require an understanding of the patient characteristics and treatment factors associated with uncontrolled hypertension. A cross-sectional survey of 3,279 patients from 52 centers in China was performed to examine potential barriers to adequate blood pressure control of hypertensive patients with CHD. Uncontrolled hypertension was defined as blood pressure ?130/or 80 mmHg. Multivariable logistic regression was used to identify factors associated with poor blood pressure control. Mean age of the patients was 65 years, 40% were women, and mean BMI was 25 kg/m2. Mean systolic blood pressure was 136±18 mmHg and mean diastolic blood pressure was 80±11 mmHg. Only 18% of patients had a mean blood pressure <130/80 mmHg during the study period. Multivariate analysis revealed several independent factors of poor blood pressure control: body mass index ?23 kg/m2, the presence of stable angina pectoris (SAP), family history of diabetes, and use of calcium channel blockers (CCB). Further analysis showed that non-dihydropyridine calcium antagonist was significantly correlated with low BP control rate. Some of these may be amenable to modification. The results of our study suggest that overweight, the presence of SAP and family history of diabetes are important factors for tight BP control in primary care. In addition, non-dihydropyridine calcium channel blockers appear less effective than other therapies in control of blood pressure and should not be the first choice among hypertensive patients with CHD. Further identification of patients at risk of poor BP control can lead to targeted interventions to improve management.

Zhang, Yi; Li, Xin; Lei, Hou; Wei, Yidong; Li, Weiming; Hu, Dayi; Wedick, Nicole M.; Wang, Jinsong; Xu, Yawei; Li, Jue; Ma, Yunsheng

2013-01-01

260

Trust in Physicians and Blood Pressure Control in Blacks and Whites Being Treated for Hypertension in the Regards Study  

PubMed Central

Objectives Among persons treated for hypertension, Blacks are more likely to have uncontrolled blood pressure compared to Whites. Few studies have focused on trust in physicians as a potential contributor to this disparity in blood pressure (BP) control. The primary objective of this study was to assess the relationship between trust in physicians and blood pressure control among Blacks and Whites being treated for hypertension. Design Cross-sectional analysis of baseline data collected from the REasons for Geographic And Racial Differences in Stroke cohort, a US national, population-based cohort study. Participants were recruited by telephone from 2003–2007, completed a telephone survey, and had BP measured during an in-home visit. Participants 2843 Black and White adults aged >45 years with treated hypertension. Main Outcome Measures Uncontrolled blood pressure was defined as systolic blood pressure >140 mm Hg or diastolic blood pressure >90 mm Hg. For participants with diabetes, renal disease, or self-reported previous myocardial infarction, uncontrolled blood pressure was defined as systolic blood pressure >130 mm Hg or diastolic blood pressure >80 mm Hg. Results Trust in physicians was not associated with uncontrolled blood pressure in either unadjusted (odd ratio [OR] 1.07; 95% confidence interval [CI] 0.92, 1.25) or adjusted analyses (OR 0.97; 0.83, 1.14). Both Black race (OR 1.58; 1.36, 1.84) and imperfect medication adherence (OR 1.56; 1.31, 1.86) were associated with higher odds of uncontrolled blood pressure. Conclusions Trust in physicians was not related to blood pressure control among Blacks and Whites with treated hypertension in this sample. The racial disparity in blood pressure control was not completely explained by trust in physicians or medication adherence, and a better understanding of the mechanisms leading to this disparity is needed.

Durant, Raegan W.; McClure, Leslie A.; Halanych, Jewell H.; Lewis, Cora E.; Prineas, Ronald J.; Glasser, Stephen P.; Safford, Monika M.

2011-01-01

261

Secretion management in the mechanically ventilated patient.  

PubMed

Secretion management in the mechanically ventilated patient includes routine methods for maintaining mucociliary function, as well as techniques for secretion removal. Humidification, mobilization of the patient, and airway suctioning are all routine procedures for managing secretions in the ventilated patient. Early ambulation of the post-surgical patient and routine turning of the ventilated patient are common secretion-management techniques that have little supporting evidence of efficacy. Humidification is a standard of care and a requisite for secretion management. Both active and passive humidification can be used. The humidifier selected and the level of humidification required depend on the patient's condition and the expected duration of intubation. In patients with thick, copious secretions, heated humidification is superior to a heat and moisture exchanger. Airway suctioning is the most important secretion removal technique. Open-circuit and closed-circuit suctioning have similar efficacy. Instilling saline prior to suctioning, to thin the secretions or stimulate a cough, is not supported by the literature. Adequate humidification and as-needed suctioning are the foundation of secretion management in the mechanically ventilated patient. Intermittent therapy for secretion removal includes techniques either to simulate a cough, to mechanically loosen secretions, or both. Patient positioning for secretion drainage is also widely used. Percussion and postural drainage have been widely employed for mechanically ventilated patients but have not been shown to reduce ventilator-associated pneumonia or atelectasis. Manual hyperinflation and insufflation-exsufflation, which attempt to improve secretion removal by simulating a cough, have been described in mechanically ventilated patients, but neither has been studied sufficiently to support routine use. Continuous lateral rotation with a specialized bed reduces atelectasis in some patients, but has not been shown to improve secretion removal. Intrapulmonary percussive ventilation combines percussion with hyperinflation and a simulated cough, but the evidence for intrapulmonary percussive ventilation in mechanically ventilated patients is insufficient to support routine use. Secretion management in the mechanically ventilated patient consists of appropriate humidification and as-needed airway suctioning. Intermittent techniques may play a role when secretion retention persists despite adequate humidification and suctioning. The technique selected should remedy the suspected etiology of the secretion retention (eg, insufflation-exsufflation for impaired cough). Further research into secretion management in the mechanically ventilated patient is needed. PMID:17894902

Branson, Richard D

2007-10-01

262

The role of religion in relation to blood pressure control among a Southern California Thai population with hypertension.  

PubMed

This qualitative research investigates the role religion plays in relation to blood pressure control among a Southern California Thai population with hypertension. A total of 15 Thai individuals between the ages of 45-95 were interviewed. All participants indicated that stress plays a significant role in determining their ability to manage hypertension. Of the 15 participants, 14 acknowledged that religion plays an important role by helping them manage their stress level and offering them beneficial instruction about health practices such as diet and exercise. PMID:20232251

Naewbood, Supaporn; Sorajjakool, Siroj; Triamchaisri, Somporn Kantharadussadee

2012-03-01

263

The effect of ventilation on spontaneous heating of coal  

Microsoft Academic Search

Ventilation plays an important role in the spontaneous heating of coal in an underground coal mine. If the ventilation rate is too high, heat is carried away by convection. If the ventilation rate is too low, the reaction rate becomes oxygen-limited. The effect of ventilation on the spontaneous heating of coal was investigated in an isothermal oven in this study.

Liming Yuan; Alex C. Smith

264

Variability in mean duration of mechanical ventilation among community hospitals.  

PubMed

We explored intensive care units' mean ventilator-days per patient as a possible objective alternative to ventilator-associated pneumonia rates for assessing quality of care for ventilated patients. Mean ventilator-days per patient varied 4-fold within a network of community hospitals despite adjusting for multiple patient and hospital factors. Further assessment of this metric is warranted. PMID:22561723

Klompas, Michael; Kleinman, Ken P; Karcz, Anita

2012-04-24

265

Volume-limited and volume-targeted ventilation.  

PubMed

This article shows that volume-targeted ventilation is physiologically more logical than pressure-limited ventilation, and is associated with a reduced risk of pneumothorax, hypocarbia, duration of ventilation, death or bronchopulmonary dysplasia, and severe intraventricular hemorrhage. Therefore, it should now be adopted as the main mode for mechanical ventilation of preterm neonates. PMID:22954266

Morley, Colin J

2012-09-01

266

Natural ventilation for passive cooling: measurement of discharge coefficients  

Microsoft Academic Search

For the design of natural ventilation systems for passive cooling in buildings, engineers and architects are interested in the prediction of ventilation rates as a function of position and size of the ventilation openings. In common use, there are both simple and detailed (i.e., multizone) ventilation models which rely basically on the same Bernoulli algorithm to describe airflow through large

F. Flourentzou; J. Van der Maas; C.-A. Roulet

1998-01-01

267

Non-Stationary Ventilation Conditions with Open Mine Fires.  

National Technical Information Service (NTIS)

Open mine fires lead to the occurrence, in non-horizontal ventilation roads, of a driving effect, which for ascensional ventilation leads to an increase, and for descensional ventilation to a decrease, in the amount of ventilation. From this it follows th...

W. Trutwin

1977-01-01

268

Analysis of trials comparing High Frequency Ventilation with Conventional Mechanical Ventilation : Clinical Epidemiology in Intensive Care  

Microsoft Academic Search

An abundance of experimental and clinical evidence indicates that mechanical ventilation can cause ventilator induced lung damage (VILI). Primary mechanisms leading to VILI are volutrauma, i.e. use of large tidal volumes resulting in over-distension, and atelectotrauma, i.e. repetitive closing and opening of alveoli, causing shear stress. Ideally, mechanical ventilation should supply enough airway pressure, even in the end-expiratory phase of

C. W. Bollen

2006-01-01

269

Carbon dioxide mandatory ventilation (CO2MV): A new method for weaning from mechanical ventilation  

Microsoft Academic Search

Summary  We describe a new technique specially designed for weaning from mechanical ventilation: carbon dioxide mandatory ventilation\\u000a (CO2MV). CO2MV is based on feedback between end tidal expired partial pressure of carbon dioxide and ventilatory mode, controlled\\u000a or spontaneous. In order to evaluate its real interest we performed a randomized prospective study, CO2MV vs Intermittent\\u000a Mandatory Ventilation (IMV) and T. Tube Method

C. Chopin; M. C. Chambrin; J. Mangalaboyi; P. Lestavel; F. Fourrier

1989-01-01

270

21 CFR 868.5895 - Continuous ventilator.  

Code of Federal Regulations, 2013 CFR

...Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5895 Continuous ventilator. (a) Identification. A continuous...

2013-04-01

271

Monitoring ventilator weaning--predictors of success.  

PubMed

Improving the prediction of successful ventilator weaning and extubation is a goal that all Intensivists and perioperative physicians strive for. The successful wean and extubation of ventilated patients decreases hospital length of stay and associated costs, but more importantly it also reduces patient morbidity and mortality. This review evaluates traditional and novel indices used in the assessment for ventilatory wean readiness. Novel equipment such as the Bicore pulmonary monitor and the CO2 SMO Plus are now available on the market to assess and monitor ventilator weaning and may offer some value in this process. We also review the non-respiratory factors affecting weaning and the role of the bedside nurse and respiratory therapist. Resolution of the pulmonary compromise and an understanding of respiratory physiology, used in conjunction with monitored indices of weaning parameters in a consistent fashion will continue to improve our success rates of ventilator weaning and extubation. PMID:12580224

Weavind, L; Shaw, A D; Feeley, T W

2000-01-01

272

46 CFR 98.25-75 - Ventilation.  

Code of Federal Regulations, 2012 CFR

...MISCELLANEOUS VESSELS SPECIAL CONSTRUCTION, ARRANGEMENT, AND OTHER PROVISIONS FOR CERTAIN DANGEROUS CARGOES IN BULK Anhydrous Ammonia in Bulk § 98.25-75 Ventilation. (a) All enclosed spaces containing cargo tanks fitted with bottom...

2012-10-01

273

46 CFR 111.105-21 - Ventilation.  

Code of Federal Regulations, 2012 CFR

...105-21 Section 111.105-21 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Hazardous Locations § 111.105-21 Ventilation. A...

2012-10-01

274

Eustachian tube function after transmyringeal ventilation.  

PubMed

This study anus at determining the effect of transmyringeal ventilation on Eustachian tube functions. Seventy ears clinically diagnosed as having otitis media with effusion or grade I and II retraction of pars-tensa of tympanic membrane were treated with antiallergics, decongestants, mucolytics, and antibiotics as required for maximum upto three months. In forty-five ears that showed neither symptomatic nor audiometric improvement, transmyringeal ventilation was restored by myringotomy and ventilation tube insertion. There after, Eustachian tube functions were assessed by using pressure equilibration test. The post-operative audiograms showed mean hearing gain of 16. 6 dB (S D±7.9) in majority (96%) of the ears. At first week 93% ears could not either totally or partially equilibrate positive or negative pressure. The percentage in the poor function group remained 91% even at the end of 6 months showing no significant effect of ventilation tube insertion on active ET functions. PMID:23120122

Gupta, S C; Malhotra, M; Singh, M

2005-01-01

275

30 CFR 75.333 - Ventilation controls.  

Code of Federal Regulations, 2013 CFR

...HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.333...Conducting Strength Tests of Panels for Building Constructionâ (Section 12âTransverse...Conducting Strength Tests of Panels for Building Constructionâ is incorporated...

2013-07-01

276

Waste tank ventilation system waste material accumulations  

SciTech Connect

This paper calculates the amount of material that accumulates in the ventilation systems of various Tank Waste Remediation System facilities and estimates the amount of material that could be released due to a rapid pressurization.

Van Vleet, R.J., Westinghouse Hanford

1996-08-06

277

Demand Controlled Ventilating Systems: Sensor Tests.  

National Technical Information Service (NTIS)

A test program has been designed to evaluate the performance characteristics of sensors for the automatic control of ventilation rates. The test program consists of two main parts, one being the evaluation of sensor performance in laboratory tests and the...

P. Fahlen H. Andersson S. Ruud

1992-01-01

278

24 CFR 3285.505 - Crawlspace ventilation.  

Code of Federal Regulations, 2013 CFR

...the entry of rodents. In areas subject to freezing, the coverings for the ventilation openings...the skirting to the outside. Any surface water runoff from the furnace, air conditioning, or water heater drains must be directed away...

2013-04-01

279

EVALUATION OF VENTILATION PERFORMANCE FOR INDOOR SPACE  

EPA Science Inventory

The paper discusses a personal-computer-based application of computational fluid dynamics that can be used to determine the turbulent flow field and time-dependent/steady-state contaminant concentration distributions within isothermal indoor space. (NOTE: Ventilation performance ...

280

Impact of carbon storage on shallow ground water and pressure-controlled regional capacity for brine aquifers  

NASA Astrophysics Data System (ADS)

Injection of large volumes of carbon dioxide into the subsurface could affect shallow ground water by a domino effect, not including leakage through wells and faults. Using analytical and numerical models, we explore conditions under which ground water would be impacted by brine displacement. This work is limited to single- phase flow under the assumption that, far away from the injection site, details of two-phase flow are not as relevant as pressure buildup during injection. We carried out the exercise in the Texas Gulf Coast area where data are relatively abundant and in other generic basins. Preliminary results suggest that, in some circumstances (e.g., springs along fault lines focusing flow), ground water will be impacted relatively early after regional injection. This work ties in with pressure-controlled regional capacity assessments and has bearings on carbon storage policy. Capacity assessments are constrained by the level of acceptable risks, such as avoiding volumes with high well or fault density. Closed systems are pressure-controlled in that they need to stay below seal fracture pressure at all times. Capacity of open systems connected to fresh water aquifers are also interrelated to pressure that may be in some cases the limiting and controlling factor on capacity (e.g., preventing risk of well field contamination). This work is funded by the Gulf Coast Carbon Center, Austin, TX.

Nicot, J.; Hovorka, S.; Lakshminarasimhan, S.

2006-12-01

281

Humidification of inspired gases during mechanical ventilation.  

PubMed

Humidification of inspired gas is mandatory for all mechanically ventilated patients to prevent secretion retention, tracheal tube blockage and adverse changes occurring to the respiratory tract epithelium. However, the debate over "ideal" humidification continues. Several devices are available that include active and passive heat and moisture exchangers and hot water humidifiers Each have their advantages and disadvantages in mechanically ventilated patients. This review explores each device in turn and defines their role in clinical practice. PMID:22269929

Gross, J L; Park, G R

2012-01-23

282

Sensor-based demand controlled ventilation  

SciTech Connect

In most buildings, occupancy and indoor pollutant emission rates vary with time. With sensor-based demand-controlled ventilation (SBDCV), the rate of ventilation (i.e., rate of outside air supply) also varies with time to compensate for the changes in pollutant generation. In other words, SBDCV involves the application of sensing, feedback and control to modulate ventilation. Compared to ventilation without feedback, SBDCV offers two potential advantages: (1) better control of indoor pollutant concentrations; and (2) lower energy use and peak energy demand. SBDCV has the potential to improve indoor air quality by increasing the rate of ventilation when indoor pollutant generation rates are high and occupants are present. SBDCV can also save energy by decreasing the rate of ventilation when indoor pollutant generation rates are low or occupants are absent. After providing background information on indoor air quality and ventilation, this report provides a relatively comprehensive discussion of SBDCV. Topics covered in the report include basic principles of SBDCV, sensor technologies, technologies for controlling air flow rates, case studies of SBDCV, application of SBDCV to laboratory buildings, and research needs. SBDCV appears to be an increasingly attractive technology option. Based on the review of literature and theoretical considerations, the application of SBDCV has the potential to be cost-effective in applications with the following characteristics: (a) a single or small number of dominant pollutants, so that ventilation sufficient to control the concentration of the dominant pollutants provides effective control of all other pollutants; (b) large buildings or rooms with unpredictable temporally variable occupancy or pollutant emission; and (c) climates with high heating or cooling loads or locations with expensive energy.

De Almeida, A.T. [Universidade de Coimbra (Portugal). Dep. Eng. Electrotecnica; Fisk, W.J. [Lawrence Berkeley National Lab., CA (United States)

1997-07-01

283

Continuous epidural infusion for postoperative mechanical ventilation  

Microsoft Academic Search

We evaluated in analgesic and sedative effects of continuous epidural infusion of two analgesic regimens in ventilated patients\\u000a following esophagectomy. Fortysix patients, divided into two treatment groups, received postoperative continuous epidural\\u000a infusion of morphine, or that of a combination of bupivacaine and morphine. Assessments were made with the following indices:\\u000a pain relief score, somnolence score, patient ventilator coordination score, and

Shinichi Sakura; Mariko Sumi; Yoji Saito; Jyunken Koh; Makoto Asano; Akio Tanaka; Yoshihiro Kosaka

1990-01-01

284

Shut-off mechanism for ventilation hose  

DOEpatents

A shut-off mechanism to provide automatic closure of a ventilation hose when the operation of drawing air through the hose is terminated. The mechanism includes a tube of light gauge metal inside of which are mounted a plurality of louver doors positioned in the closed position due to gravity when the ventilation unit is not operational. When the unit is operational, air flowing into the unit maintains the doors in the open position. 5 figs.

Huyett, J.D.; Meskanick, G.R.

1989-12-07

285

Analytic Reviews: High-Frequency Oscillatory Ventilation (HFOV) and Airway Pressure Release Ventilation (APRV): A Practical Guide  

Microsoft Academic Search

Despite advances in ventilator management, 31% to 38% of patients with adult respiratory distress syndrome (ARDS) will die, some from progressive respiratory failure. Inability to adequately oxygenate patients with severe ARDS has prompted extensive efforts to identify what are now known as alternative modes of ventilation including high-frequency oscillatory ventilation and airway pressure release ventilation. Both modalities are based on

S. P. Stawicki; Munish Goyal; Babak Sarani

2009-01-01

286

Ventilation criteria for IDMS facility  

SciTech Connect

Both Facility Evaluation Board (FEB) reviews of the Integrated DWPF Melter System (IDMS) have identified the inconsistency of the current IDMS Process Hazards Review (PHR) versus actual IDMS practice as regards the criteria to contain air borne pollutants that may be present in the Process Room (e.g. benzene and mercury). The PHR states that a 1.0 in. wc pressure differential be maintained between the IDMS Process Room and Building 672-T. In addition, the PHR further specifies that the linear velocity through openings into the Process Room (e.g. open doors) be equal to or greater than 150 fpm. Finally, the PHR recommended that mercury vapor and benzene monitors be installed in the Process Room ventilation exhaust to alert personnel to the presence of vapors of benzene and/or mercury before entering the Process Room. This report summarizes the results of reassessment of these criteria and the specific recommendation for permanent installation of mercury and benzene vapor monitors in the vapor exhaust of the Process Room.

Lambert, D.P.

1996-07-03

287

Transpleural ventilation of explanted human lungs  

PubMed Central

Background The hypothesis that ventilation of emphysematous lungs would be enhanced by communication with the parenchyma through holes in the pleural surface was tested. Methods Fresh human lungs were obtained from patients with emphysema undergoing lung transplantation. Control human lungs were obtained from organ donors whose lungs, for technical reasons, were not considered suitable for implantation. Lungs were ventilated through the bronchial tree or transpleurally via a small hole communicating with the underlying parenchyma over which a flanged silicone tube had been cemented to the surface of the lung (spiracle). Measurements included flow?volume?time curves during passive deflation via each pathway; volume of trapped gas recovered from lungs via spiracles when no additional gas was obtainable passively from the airways; and magnetic resonance imaging assessment of spatial distribution of hyperpolarised helium (3He) administered through either the airways or spiracles. Results In emphysematous lungs, passively expelled volumes at 20?s were 94% greater through spiracles than via the airways. Following passive deflation from the airways, an average of 1.07?litres of trapped gas volume was recoverable via spiracles. Regions were ventilated by spiracles that were less well ventilated via bronchi. Conclusions Because of the extensive collateral ventilation present in emphysematous lungs, direct communication with the lung parenchyma through non?anatomical pathways has the potential to improve the mechanics of breathing and hence ventilation.

Choong, Cliff K; Macklem, Peter T; Pierce, John A; Lefrak, Stephen S; Woods, Jason C; Conradi, Mark S; Yablonskiy, Dimitry A; Hogg, James C; Chino, Kimiaki; Cooper, Joel D

2007-01-01

288

Active Ventilation Report RCDP Cycle II.  

SciTech Connect

This report documents the analysis of the performance of natural and mechanical ventilation in Pacific Northwest homes. The analysis was part of Cycle 2 of the Residential Construction Demonstration Project, sponsored by Bonneville Power Administration (BPA). Since 1986, the Residential Construction Demonstration Project (RCDP) has sponsored the collection of data on energy efficient homes in the Pacific Northwest that comply with these new standards and requirements. Cycle 2 of RCDP was conducted between September 1987 and April 1990. It concentrated on energy innovations in homes built to the Super Good Cents specifications. All of the test homes have electric heat and mechanical ventilation systems. Seven different types of active ventilation systems are represented in the homes. Three of these system types are equipped with heat recovery devices, and are represented in approximately a quarter of the test homes. The potential for both natural and mechanical ventilation was measured. Potential structural leakage was measured by blower door testing. Flow rate and operating time of mechanical ventilation systems were measured with flow hoods and hour meters. Actual ventilation was measured by using a passive tracer gas technique for several weeks during the heating season and at times of normal occupancy. 3 refs., 12 figs., 4 tabs.

Douglass, John G., Palmiter, Larry S., Brown, Ian, Bond, Tami, Washington State Energy Office

1991-02-01

289

Injurious mechanical ventilation affects neuronal activation in ventilated rats  

PubMed Central

Introduction Survivors of critical illness often have significant long-term brain dysfunction, and routine clinical procedures like mechanical ventilation (MV) may affect long-term brain outcome. We aimed to investigate the effect of the increase of tidal volume (Vt) on brain activation in a rat model. Methods Male Sprague Dawley rats were randomized to three groups: 1) Basal: anesthetized unventilated animals, 2) low Vt (LVt): MV for three hours with Vt 8 ml/kg and zero positive end-expiratory pressure (ZEEP), and 3) high Vt (HVt) MV for three hours with Vt 30 ml/kg and ZEEP. We measured lung mechanics, mean arterial pressure (MAP), arterial blood gases, and plasma and lung levels of cytokines. We used immunohistochemistry to examine c-fos as a marker of neuronal activation. An additional group of spontaneously breathing rats was added to discriminate the effect of surgical procedure and anesthesia in the brain. Results After three hours on LVt, PaO2 decreased and PaCO2 increased significantly. MAP and compliance remained stable in MV groups. Systemic and pulmonary inflammation was higher in MV rats than in unventilated rats. Plasma TNF? was significantly higher in HVt than in LVt. Immunopositive cells to c-fos in the retrosplenial cortex and thalamus increased significantly in HVt rats but not in LVt or unventilated rats. Conclusions MV promoted brain activation. The intensity of the response was higher in HVt animals, suggesting an iatrogenic effect of MV on the brain. These findings suggest that this novel cross-talking mechanism between the lung and the brain should be explored in patients undergoing MV.

2011-01-01

290

Dependence of ventilation image derived from 4D CT on deformable image registration and ventilation algorithms.  

PubMed

Ventilation imaging using 4D CT is a convenient and low-cost functional imaging methodology which might be of value in radiotherapy treatment planning to spare functional lung volumes. Deformable image registration (DIR) is needed to calculate ventilation imaging from 4D CT. This study investigates the dependence of calculated ventilation on DIR methods and ventilation algorithms. DIR of the normal end expiration and normal end inspiration phases of the 4D CT images was used to correlate the voxels between the two respiratory phases. Three different DIR algorithms, optical flow (OF), diffeomorphic demons (DD), and diffeomorphic morphons (DM) were retrospectively applied to ten esophagus and ten lung cancer cases with 4D CT image sets that encompassed the entire lung volume. The three ventilation extraction methods were used based on either the Jacobian, the change in volume of the voxel, or directly calculated from Hounsfield units. The ventilation calculation algorithms used are the Jacobian, ?V, and HU method. They were compared using the Dice similarity coefficient (DSC) index and Bland-Altman plots. Dependence of ventilation images on the DIR was greater for the ?V and the Jacobian methods than for the HU method. The DSC index for 20% of low-ventilation volume for ?V was 0.33 ± 0.03 (1 SD) between OF and DM, 0.44 ± 0.05 between OF and DD, and 0.51 ± 0.04 between DM and DD. The similarity comparisons for Jacobian were 0.32 ± 0.03, 0.44 ± 0.05, and 0.51 ± 0.04, respectively, and for HU they were 0.53 ± 0.03, 0.56 ± 0.03, and 0.76 ± 0.04, respectively. Dependence of extracted ventilation on the ventilation algorithm used showed good agreement between the ?V and Jacobian methods, but differed significantly for the HU method. DSC index for using OF as DIR was 0.86 ± 0.01 between ?V and Jacobian, 0.28 ± 0.04 between ?V and HU, and 0.28 ± 0.04 between Jacobian and HU, respectively. When using DM or DD as DIR, similar values were obtained when comparing the different ventilation calculation methods. The similarity values for the 20% high-ventilation volume were close to those found for the 20% low-ventilation volume. The results obtained with DSC index were confirmed when using the Bland-Altman plots for comparing the ventilation images. Our data suggest that ventilation calculated from 4D CT depends on the DIR algorithm employed. Similarities between ?V and Jacobian are higher than between ?V and HU, and Jacobian and HU. PMID:23835389

Latifi, Kujtim; Forster, Kenneth M; Hoffe, Sarah E; Dilling, Thomas J; van Elmpt, Wouter; Dekker, Andre; Zhang, Geoffrey G

2013-07-08

291

Pneumococcal Conjugate Vaccine (PCV7)  

MedlinePLUS

... the intervals between doses will depend on the child's age. Ask your health care provider for details.Children 2 through 4 Years ... allergy to any vaccine component. Tell your health-care provider if your child has ever had a severe reaction to any ...

292

Noninvasive Methods for Measuring Ventilation in Mobile Subjects. Part 1. Measurements of Ventilation in Freely Ranging Subjects. Part 2. Assessment of Heart Rate as a Predictor of Ventilation.  

National Technical Information Service (NTIS)

Ventilation, a measure of the frequency and depth of breathing, is an important determinant of the amounts of indoor and outdoor air pollutants that enter the respiratory tract. Increasing ventilation (for example, through exercise) increases the amounts,...

P. D. McCool J. M. Samet W. E. Lambert D. S. James C. M. Mermier

1993-01-01

293

Non-invasive ventilation and continuous positive pressure ventilation in emergency departments: where are we now?  

Microsoft Academic Search

A number of emergency departments have introduced non-invasive positive pressure ventilation (NIV) and continuous positive airway pressure (CPAP) for patients presenting with acute respiratory failure. It is thought that early non-invasive respiratory support will avoid the need for invasive ventilation in many cases. This literature review studied current knowledge of NIV and CPAP in the acute setting with the aim

R Bolton; A Bleetman

2008-01-01

294

Xe-133 rebreathing system for ventilation studies on ventilator-assisted patients  

SciTech Connect

The authors describe a manually operated system, simple to assemble, that will enable xenon-133 lung ventilation studies to be performed on ventilator-assisted patients. It can be constructed from items readily available. Radiation exposure levels to the operator were measured and are reported.

Wiesen, E.J.; Miron, S.D.; Bellon, E.M.

1984-10-01

295

Physiologic Determinants of Ventilator Dependence in Long-term Mechanically Ventilated Patients  

Microsoft Academic Search

To investigate the pathophysiologic mechanisms of ventilator de- pendence, we took physiologic measurements in 28 patients with COPD and 11 postcardiac surgery (PCS) patients receiving long- term mechanical ventilation during a spontaneous breathing trial, and in 20 stable, spontaneously breathing patients matched for age and disease. After 40 6 14 min of spontaneous breathing, 20 of 28 patients with COPD

ANDREA PURRO; LORENZO APPENDINI; ANDREA DE GAETANO; MARTA GUDJONSDOTTIR; CLAUDIO F. DONNER; ANDREA ROSSI

2000-01-01

296

Jet ventilation à haute fréquence combinée à la ventilation mécanique conventionnelle dans le traitement du SDRA  

Microsoft Academic Search

Better understanding of the physiopathology of ventilatory mechanisms associated with ARDS and the recent re-evaluation of the iatrogenic potential of mechanical ventilation (MV) brings us closer to the best suited ventilatory mode for these patients. In severely ill ARDS patients, only a small lung volume is ventilated, and remains available for the totality of the gas exchanges (baby lung concept).

J. P. Roustan

1995-01-01

297

Metformin attenuates ventilator-induced lung injury  

PubMed Central

Introduction Diabetic patients may develop acute lung injury less often than non-diabetics; a fact that could be partially ascribed to the usage of antidiabetic drugs, including metformin. Metformin exhibits pleiotropic properties which make it potentially beneficial against lung injury. We hypothesized that pretreatment with metformin preserves alveolar capillary permeability and, thus, prevents ventilator-induced lung injury. Methods Twenty-four rabbits were randomly assigned to pretreatment with metformin (250 mg/Kg body weight/day per os) or no medication for two days. Explanted lungs were perfused at constant flow rate (300 mL/min) and ventilated with injurious (peak airway pressure 23 cmH2O, tidal volume ?17 mL/Kg) or protective (peak airway pressure 11 cmH2O, tidal volume ?7 mL/Kg) settings for 1 hour. Alveolar capillary permeability was assessed by ultrafiltration coefficient, total protein concentration in bronchoalveolar lavage fluid (BALF) and angiotensin-converting enzyme (ACE) activity in BALF. Results High-pressure ventilation of the ex-vivo lung preparation resulted in increased microvascular permeability, edema formation and microhemorrhage compared to protective ventilation. Compared to no medication, pretreatment with metformin was associated with a 2.9-fold reduction in ultrafiltration coefficient, a 2.5-fold reduction in pulmonary edema formation, lower protein concentration in BALF, lower ACE activity in BALF, and fewer histological lesions upon challenge of the lung preparation with injurious ventilation. In contrast, no differences regarding pulmonary artery pressure and BALF total cell number were noted. Administration of metformin did not impact on outcomes of lungs subjected to protective ventilation. Conclusions Pretreatment with metformin preserves alveolar capillary permeability and, thus, decreases the severity of ventilator-induced lung injury in this model.

2012-01-01

298

Early High-Frequency Oscillatory Ventilation Versus Synchronized Intermittent Mandatory Ventilation in Very Low Birth Weight Infants: A Pilot Study of Two Ventilation Protocols  

Microsoft Academic Search

OBJECTIVE:To evaluate the feasibility of conducting a prospective, randomized trial comparing early high-frequency oscillatory ventilation (HFOV) to synchronized intermittent mandatory ventilation (SIMV) in very low birth weight (VLBW) premature infants. This pilot study evaluated two ventilator management protocols to determine how well they could be implemented in a multicenter clinical trial. Although this pilot study was not powered to detect

David J Durand; Jeanette M Asselin; Mark L Hudak; Judy L Aschner; Robert D McArtor; John P Cleary; Krisa P VanMeurs; Daniel L Stewart; Craig T Shoemaker; Thomas E Wiswell; Sherry E Courtney

2001-01-01

299

High-Frequency Oscillatory Ventilation, Partial Liquid Ventilation, or Conventional Mechanical Ventilation in NewbornPiglets with Saline Lavage-Induced Acute Lung Injury  

Microsoft Academic Search

It has been reported that, in diseased lungs, either partial liquid ventilation (PLV) or high-frequency oscillatory ventilation (HFOV) can improve oxygenation better and with less lung injury than conventional mechanical ventilation (CMV). This study was intended as a preclinical comparison between the effects of HFOV, PLV and CMV on gas exchange, lung mechanics and histology. Fifteen anesthetized newborn piglets, with

Pieter L. J. Degraeuwe; Frederik B. J. M. Thunnissen; Gijs D. Vos; Carlos E. Blanco

1999-01-01

300

46 CFR 108.187 - Ventilation for brush type electric motors in classified spaces.  

Code of Federal Regulations, 2010 CFR

... false Ventilation for brush type electric motors in classified spaces...187 Ventilation for brush type electric motors in classified spaces. Ventilation for brush type electric motors in classified...

2010-10-01

301

46 CFR 108.187 - Ventilation for brush type electric motors in classified spaces.  

Code of Federal Regulations, 2010 CFR

... false Ventilation for brush type electric motors in classified spaces...187 Ventilation for brush type electric motors in classified spaces. Ventilation for brush type electric motors in classified...

2009-10-01

302

An electrical analogue for a pressure-controlled, fluid flow generator for arterial blood-flow simulation.  

PubMed

To study the human arterial system, we constructed a pressure-controlled, fluid flow generator [1] that allows simulation of pressure and flow waves in a hydraulic system in which the arteries are simulated by collapsible tubes. In this paper we elaborate an electrical analogue of this flow generator. The analogue circuit contains only five electrical components: a source resistance and inductance, and a downstream resistance, inductance and capacitance. The values of the components are obtained from a function fit to the pressure and flow waves generated during steady and pulsatile flow measurements. The pulsation and relaxation times calculated from the analogue model are compared with experimental values. This electrical analogue allows computer simulation of the arterial pressure and flow waves. PMID:2023232

Janssens, J L; Raman, E R

303

Take Control of Your Blood pressure (TCYB) study: A multifactorial tailored behavioral and educational intervention for achieving blood pressure control  

PubMed Central

Objectives Evaluating a randomized controlled trial involving a tailored behavioral intervention conducted to improve blood pressure control. Methods Adults with hypertension from two outpatient primary care clinics were randomly allocated to receive a nurse-administered behavioral intervention or usual care. In this ongoing study, patients receive the tailored behavioral intervention bi-monthly for two years via telephone; the goal of the intervention is to promote medication adherence and improve hypertension-related health behaviors. Patient factors targeted in the tailored behavioral intervention include perceived risk of hypertension and knowledge, memory, medical and social support, patients' relationship with their health care provider, adverse effects of medication therapy, weight management, exercise, diet, stress, smoking, and alcohol use. Results The sample randomized to the behavioral intervention consisted of 319 adults with hypertension (average age = 60.5 years; 47% African-American). A comparable sample of adults was assigned to usual care (n=317). We had a 96% retention rate for the overall sample for the first 6 months of the study (93% at 12 months). The average phone call has lasted 18 minutes (range 2 to 51 minutes). From baseline to six months, self-reported medication adherence increased by 9% in the behavioral group vs. 1% in the non-behavioral group. Conclusion The intervention is easily implemented and is designed to enhance adherence with prescribed hypertension regimen. The study includes both general and patient-tailored information based upon need assessment. The study design ensures internal validity as well as the ability to generalize study findings to the clinic settings. Practice Implications Despite knowledge of the risks and acceptable evidence, a large number of hypertensive adults still do not have their blood pressure under effective control. This study will be an important step in evaluating a tailored multibehavioral intervention focusing on improving blood pressure control.

Bosworth, Hayden B.; Olsen, Maren K; Neary, Alice; Orr, Melinda; Grubber, Janet; Svetkey, Laura; Adams, Martha; Oddone, Eugene Z.

2008-01-01

304

WASTE HANDLING BUILDING VENTILATION SYSTEM DESCRIPTION DOCUMENT  

SciTech Connect

The Waste Handling Building Ventilation System provides heating, ventilation, and air conditioning (HVAC) for the contaminated, potentially contaminated, and uncontaminated areas of the Monitored Geologic Repository's (MGR) Waste Handling Building (WHB). In the uncontaminated areas, the non-confinement area ventilation system maintains the proper environmental conditions for equipment operation and personnel comfort. In the contaminated and potentially contaminated areas, in addition to maintaining the proper environmental conditions for equipment operation and personnel comfort, the contamination confinement area ventilation system directs potentially contaminated air away from personnel in the WHB and confines the contamination within high-efficiency particulate air (HEPA) filtration units. The contamination confinement areas ventilation system creates airflow paths and pressure zones to minimize the potential for spreading contamination within the building. The contamination confinement ventilation system also protects the environment and the public by limiting airborne releases of radioactive or other hazardous contaminants from the WHB. The Waste Handling Building Ventilation System is designed to perform its safety functions under accident conditions and other Design Basis Events (DBEs) (such as earthquakes, tornadoes, fires, and loss of the primary electric power). Additional system design features (such as compartmentalization with independent subsystems) limit the potential for cross-contamination within the WHB. The system provides status of important system parameters and equipment operation, and provides audible and/or visual indication of off-normal conditions and equipment failures. The Waste Handling Building Ventilation System confines the radioactive and hazardous material within the building such that the release rates comply with regulatory limits. The system design, operations, and maintenance activities incorporate ALARA (as low as is reasonably achievable) principles to maintain personnel radiation doses to all occupational workers below regulatory limits and as low as is reasonably achievable. The Waste Handling Building Ventilation System interfaces with the Waste Handling Building System by being located within the WHB and by maintaining specific pressures, temperatures, and humidity within the building. The system also depends on the WHB for water supply. The system interfaces with the Site Radiological Monitoring System for continuous monitoring of the exhaust air; the Waste Handling Building Fire Protection System for detection of fire and smoke; the Waste Handling Building Electrical System for normal, emergency, and standby power; and the Monitored Geologic Repository Operations Monitoring and Control System for monitoring and control of the system.

P.A. Kumar

2000-06-21

305

WASTE TREATMENT BUILDING VENTILATION SYSTEM DESCRIPTION DOCUMENT  

SciTech Connect

The Waste Treatment Building Ventilation System provides heating, ventilation, and air conditioning (HVAC) for the contaminated, potentially contaminated, and uncontaminated areas of the Monitored Geologic Repository's (MGR) Waste Treatment Building (WTB). In the uncontaminated areas, the non-confinement area ventilation system maintains the proper environmental conditions for equipment operation and personnel comfort. In the contaminated and potentially contaminated areas, in addition to maintaining the proper environmental conditions for personnel comfort and equipment operation, the contamination confinement area ventilation system directs potentially contaminated air away from personnel in the WTB and confines the contamination within high-efficiency particulate air (HEPA) filtration units. The contamination confinement area ventilation system creates airflow paths and pressure zones to minimize the potential for spreading contamination with the building. The contamination confinement ventilation system also protects the environment and the public by limiting airborne releases of radioactive or other hazardous contaminants from the WTB. The Waste Treatment Building Ventilation System confines the radioactive and hazardous material within the building such that the release rates comply with regulatory limits, The system design, operations, and maintenance activities incorporate ALARA (as low as is reasonably achievable) principles to maintain personnel radiation doses to all occupational workers below regulatory limits and as low as is reasonably achievable. The system provides status of important system parameters and equipment operation, and provides audible and/or visual indication of off-normal conditions and equipment failures. The Waste Treatment Building Ventilation System interfaces with the Waste Treatment Building System by being located in the WTB, and by maintaining specific pressure, temperature, and humidity environments within the building. The system also depends on the WTB for normal electric power supply and the required supply of water for heating, cooling, and humidification. Interface with the Waste Treatment Building System includes the WTB fire protection subsystem for detection of fire and smoke. The Waste Treatment Building Ventilation System interfaces with the Site Radiological Monitoring System for continuous monitoring of the exhaust air and key areas within the WTB, the Monitored Geologic Repository Operations Monitoring and Control System for monitoring and control of system operations, and the Site Generated Radiological Waste Handling System and Site Generated Hazardous, Non-Hazardous & Sanitary Waste Disposal System for routing of pretreated toxic, corrosive, and radiologically contaminated effluent from process equipment to the HEPA filter exhaust ductwork and air-cleaning unit.

P.A. Kumar

2000-06-22

306

[Mechanical ventilation of acute lung injury].  

PubMed

Acute lung injury (ALI) is of paramount importance for modern intensive care since it is one of the most frequent conditions necessitating admission to an ICU. ALI is characterised by severe life threatening hypoxemia which is based on ventilation perfusion mismatching within the lung. This is mostly resulting from atelectasis formation due to primary or secondary inflammation of lung tissue. Many studies showed that this inflammatory process is not restricted to the respiratory system but might result in non pulmonary organ failure and hemodynamic compromise as well. Mechanical ventilation is considered the hallmark treatment for ALI patients aimed to recruit lung tissue and thereby reverse hypoxemia without causing additional lung injury potentially resulting from overdistention or cycling collapse during expiration. Scientific evidence shows us that prevention of ventilator induced lung injury by protective ventilation with reduced tidal volumes is resulting in better clinical outcomes. Moreover, different technologies and adjunctive therapies have been suggested based on their pathophysiology. All these treatment options will be summarized in this article. Given the clear evidence for protective ventilation and bearing in mind that clinical application of this easy concept is still not widespread we will focus on this aspect. PMID:17455139

Kuhlen, R; Dembinski, R

2007-04-01

307

Dynamic behavior during noninvasive ventilation: chaotic support?  

PubMed

Acute noninvasive ventilation is generally applied via face mask, with modified pressure support used as the initial mode to assist ventilation. Although an adequate seal can usually be obtained, leaks frequently develop between the mask and the patient's face. This leakage presents a theoretical problem, since the inspiratory phase of pressure support terminates when flow falls to a predetermined fraction of peak inspiratory flow. To explore the issue of mask leakage and machine performance, we used a mathematical model to investigate the dynamic behavior of pressure-supported noninvasive ventilation, and confirmed the predicted behavior through use of a test lung. Our mathematical and laboratory analyses indicate that even when subject effort is unvarying, pressure-support ventilation applied in the presence of an inspiratory leak proximal to the airway opening can be accompanied by marked variations in duration of the inspiratory phase and in autoPEEP. The unstable behavior was observed in the simplest plausible mathematical models, and occurred at impedance values and ventilator settings that are clinically realistic. PMID:11179109

Hotchkiss, J R; Adams, A B; Dries, D J; Marini, J J; Crooke, P S

2001-02-01

308

Mechanical ventilators as vehicles of infection.  

PubMed

Twenty-five patients from the intensive care unit who had been subjected to tracheostomy and require mechanical respiration were studied. Data are presented concerning the bacteriological controls performed on the tracheal exudates, various parts of the ventilators (Engström Model 200 and Bennett PR-2), and the Wright spirometer. The germs found were mainly pseudomonas, enterobacteriaceae germs and bacteria from the acinetobacter group. There was a high incidence of infection in the tracheostomies of these patients. We found a cause and effect relationship between the contaminating bacteria isolated from the cannula and the bacteria isolated from the tracheal exudates in the case of pseudomonas aeruginosa. However, this was not found to be the case where enterobacteriaceae were concerned. Acinetobacter calcoaceticus were isolated almost exclusively in the ventilators. The study calls attention to the need for rigorous disinfection of ventilators to prevent hospital cross infections. PMID:811072

Perea, E J; Criado, A; Moreno, M; Avello, F

1975-01-01

309

Outcome of mechanical ventilation in Central Africa.  

PubMed Central

The outcome of mechanical ventilation is reported in a prospective series of 200 patients managed in an intensive care unit in Zambia. Fifty two patients survived (26%), and 46 patients were subsequently discharged from hospital (23%). Ten patients died in whom a complication of ventilation was a factor. Patients not expected to survive by the authors had a 96.3% mortality whereas patients with a chance of survival had a mortality rate of 58.8%. Two diagnostic groups were found to have a high mortality: head injury (85.1%) and non-traumatic coma (76.4%). This series is compared with similar series from developed countries and recommendations are made for the institution of mechanical ventilation in the developing world.

Sinclair, J. R.; Watters, D. A.; Davison, M.

1988-01-01

310

MODELING VENTILATION SYSTEM RESPONSE TO FIRE  

SciTech Connect

Fires in facilities containing nuclear material have the potential to transport radioactive contamination throughout buildings and may lead to widespread downwind dispersal threatening both worker and public safety. Development and implementation of control strategies capable of providing adequate protection from fire requires realistic characterization of ventilation system response which, in turn, depends on an understanding of fire development timing and suppression system response. This paper discusses work in which published HEPA filter data was combined with CFAST fire modeling predictions to evaluate protective control strategies for a hypothetical DOE non-reactor nuclear facility. The purpose of this effort was to evaluate when safety significant active ventilation coupled with safety class passive ventilation might be a viable control strategy.

Coutts, D

2007-04-17

311

Building ventilation and indoor air quality  

SciTech Connect

Rising energy prices, among other factors, have generated an incentive to reduce ventilation rates and thereby reduce the cost of heating and cooling buildings. Reduced infiltration and ventilation in buildings may significantly increase exposure to indoor contaminants and perhaps have adverse effects on occupant health and comfort. Four indoor air contaminants - carbon monoxide and nitrogen dioxide from gas appliances; formaldehyde from particleboard, plywood, urea-formaldehyde foam insulation, and gas appliances; and radon from building materials, soil, and ground water - are currently receiving considerable attention in the context of potential health risks associated with reduced infiltration and ventilation rates. These air contaminants in conventional and energy efficient buildings were measured and analyzed with a view to assessing their potential health risks and various control strategies capable of lowering pollutant concentrations. Preliminary findings suggest that further intensive studies are needed in order to develop criteria for maintaining acceptable indoor air quality without compromising energy efficiency.

Hollowell, C.D.; Berk, J.V.; Boegel, M.L.; Miksch, R.R.; Nazaroff, W.W.; Traynor, G.W.

1980-01-01

312

Impact of two-way air flow due to temperature difference on preventing the entry of outdoor particles using indoor positive pressure control method  

Microsoft Academic Search

Maintaining positive pressure indoors using mechanical ventilation system is a popular control method for preventing the entry of outdoor airborne particles. The idea is, as long as the supply air flow rate is larger than return air flow rate, the pressure inside the ventilated room should be positive since the superfluous air flow must exfiltrate from air leakages or other

Chun Chen; Bin Zhao; Xudong Yang

2011-01-01

313

Efficacy of intermittent ventilation for providing acceptable indoor air quality  

SciTech Connect

Ventilation standards and guidelines typically treat ventilation as a constant and specify its value. In many circumstances a designer wishes to use intermittent ventilation, rather than constant ventilation, but there are no easy equivalencies available. This report develops a model of efficacy that allows one to calculate how much intermittent ventilation one needs to get the same indoor air quality as a the continuous value specified. We have found that there is a simple relationship between three dimensionless quantities: the temporal ventilation effectiveness (which we call the efficacy), the nominal turn-over and the under-ventilation fraction. This relationship allows the calculation of intermittent ventilation for a wide variety of parameters and conditions. We can use the relationship to define a critical time that separates the regime in which ventilation variations can be averaged over from the regime in which variable ventilation is of low effectiveness. We have found that ventilation load-shifting, temporary protection against poor outdoor air quality and dynamic ventilation strategies can be quite effective in low-density buildings such as single-family houses or office spaces. The results of this work enable ventilation standards and guidelines to allow this extra flexibility and still provide acceptable indoor air quality.

Sherman, M.H.

2004-10-01

314

Estimated costs of ventilation systems complying with the HUD ventilation standard for manufactured homes  

SciTech Connect

At the request of the US Department of Housing and Urban Development (HUD), the Pacific Northwest Laboratory estimated the material, labor, and operating costs for ventilation equipment needed for compliance with HUD`s proposed revision to the ventilation standard for manufactured housing. This was intended to bound the financial impacts of the ventilation standard revision. Researchers evaluated five possible prototype ventilation systems that met the proposed ventilation requirements. Of those five, two systems were determined to be the most likely used by housing manufacturers: System 1 combines a fresh air duct with the existing central forced-air system to supply and circulate fresh air to conditioned spaces. System 2 uses a separate exhaust fan to remove air from the manufactured home. The estimated material and labor costs for these two systems range from $200 to $300 per home. Annual operating costs for the two ventilation systems were estimated for 20 US cities. The estimated operating costs for System 1 ranged from $55/year in Las Vegas, Nevada, to $83/year in Bismarck, North Dakota. Operating costs for System 2 ranged from a low of $35/year in Las Vegas to $63/year in Bismarck. Thus, HUD`s proposed increase in ventilation requirements will add less than $100/year to the energy cost of a manufactured home.

Miller, J.D.; Conner, C.C.

1993-11-01

315

Thermoregulation and ventilation of termite mounds.  

PubMed

Some of the most sophisticated of all animal-built structures are the mounds of African termites of the subfamily Macrotermitinae, the fungus-growing termites. They have long been studied as fascinating textbook examples of thermoregulation or ventilation of animal buildings. However, little research has been designed to provide critical tests of these paradigms, derived from a very small number of original papers. Here I review results from recent studies on Macrotermes bellicosus that considered the interdependence of ambient temperature, thermoregulation, ventilation and mound architecture, and that question some of the fundamental paradigms of termite mounds. M. bellicosus achieves thermal homeostasis within the mound, but ambient temperature has an influence too. In colonies in comparably cool habitats, mound architecture is adapted to reduce the loss of metabolically produced heat to the environment. While this has no negative consequences in small colonies, it produces a trade-off with gas exchange in large colonies, resulting in suboptimally low nest temperatures and increased CO(2) concentrations. Along with the alteration in mound architecture, the gas exchange/ventilation mechanism also changes. While mounds in the thermally appropriate savannah have a very efficient circular ventilation during the day, the ventilation in the cooler forest is a less efficient upward movement of air, with gas exchange restricted by reduced surface exchange area. These results, together with other recent findings, question entrenched ideas such as the thermosiphon-ventilation mechanism or the assumption that mounds function to dissipate internally produced heat. Models trying to explain the proximate mechanisms of mound building, or building elements, are discussed. PMID:12743703

Korb, Judith

2003-02-11

316

Evaluation of pressure support ventilation with seven different ventilators using Active Servo Lung 5000.  

PubMed

In modern emergency and critical care, physicians tend to choose the mode of mechanical ventilation based on spontaneous breathing for the purpose of promoting discharge of pulmonary secretion and preventing atelectasis in patients with acute respiratory insufficiency. However, we often observe "differences in recovery" among patients treated using the same PSV settings beyond "differences in individual characteristics." We evaluated the Pressure Support Ventilation (PSV) mode aiming to certify the difference among 7 representative mechanical ventilators using the Active Servo Lung 5000 (ASL5000) respiratory simulation system. The following parameters were measured: The time delay that resulted in the lowest inspiratory pressure from the point at which the ventilator recognized spontaneous breathing (TD), the lowest inspiratory airway pressure (cmH2O) generated prior to the initiation of PSV (DeltaPaw), the work of breathing while triggering required to achieve the lowest inspiratory negative pressure from the beginning of inspiratory support (WOBtrig), and the inspiratory work of breathing (WOBi). The mean TD of the Puritan-Bennett type 840 (PB840) was signifi cantly shorter than those of other ventilators (p0.01). The WOBtrig of the PB840 was significantly lower than those of others (p0.01). However, the WOBi values of the Servo-I and T-Bird were greater than the others, with the Evita series showing the smallest WOBi of the 7 ventilators tested. According to this simulation study using ASL 5000, we concluded that PB840 was the most rapid response ventilator, but the Evita series was the gentlest mechanical ventilator among 7 ventilators from the standpoint of the total work of breathing during the inspiration phase in the setting of PSV. PMID:18464889

Terado, Michihisa; Ichiba, Shingo; Nagano, Osamu; Ujike, Yoshihito

2008-04-01

317

Development of push-pull ventilation  

SciTech Connect

Push-pull ventilation (air is blown across a contaminant generation area toward an exhaust hood) can have distinct advantages over exhaust ventilation alone. It can control contaminant emission into the workplace better than exhaust only, and much less conditioned air must be exhausted so there are energy savings. This paper presents suggested push and pull flow rates for open surface tank operations such as plating. About 98% of the contaminant generated can be captured by a push-pull system using the proper flow rates.

Huebener, D.J.; Hughes, R.T.

1985-05-01

318

Ventilation-perfusion imaging in pulmonary papillomatosis  

SciTech Connect

Three children with laryngeal papillomas involving the lungs had serial ventilation-perfusion scintigrams to assess results of therapy designed to reduce the bronchial involvement. Different imaging patterns were observed depending on size, number, and location of lesions. In early parenchymal involvement a ventilation-perfusion mismatch was seen. The initial and follow-up studies correlated well with clinical and radiographic findings. This noninvasive procedure is helpful in evaluating ventilatory and perfusion impairment in these patients as well as their response to treatment.

Espinola, D.; Rupani, H.; Camargo, E.E.; Wagner, H.N. Jr.

1981-11-01

319

46 CFR 190.15-15 - Ventilation for living spaces and quarters.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false Ventilation for living spaces and quarters. 190.15-15 Section 190...Ventilation § 190.15-15 Ventilation for living spaces and quarters. (a) All living spaces shall be adequately ventilated in a...

2011-10-01

320

46 CFR 190.15-15 - Ventilation for living spaces and quarters.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 false Ventilation for living spaces and quarters. 190.15-15 Section 190...Ventilation § 190.15-15 Ventilation for living spaces and quarters. (a) All living spaces shall be adequately ventilated in a...

2012-10-01

321

Ventilation and airtightness in low-rise residential buildings. Analyses and full-scale measurements.  

National Technical Information Service (NTIS)

This report examines how the airtightness affects the ventilation, the influence of ventilation on the energy balance, methods of determining the ventilation and the performance of different ventilation systems. Six different modern house are analysed. Ai...

A. Blomsterberg

1990-01-01

322

30 CFR 56.14213 - Ventilation and shielding for welding.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Ventilation and shielding for welding. 56.14213 Section 56.14213 Mineral Resources...Procedures § 56.14213 Ventilation and shielding for welding. (a) Welding operations shall be shielded when performed at...

2013-07-01

323

30 CFR 57.14213 - Ventilation and shielding for welding.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Ventilation and shielding for welding. 57.14213 Section 57.14213 Mineral Resources...Procedures § 57.14213 Ventilation and shielding for welding. (a) Welding operations shall be shielded when performed at...

2013-07-01

324

46 CFR 169.315 - Ventilation (other than machinery spaces).  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false Ventilation (other than machinery spaces). 169.315 Section 169.315 Shipping...169.315 Ventilation (other than machinery spaces). (a) All enclosed spaces within the vessel must be properly...

2011-10-01

325

46 CFR 169.315 - Ventilation (other than machinery spaces).  

Code of Federal Regulations, 2012 CFR

...2012-10-01 false Ventilation (other than machinery spaces). 169.315 Section 169.315 Shipping...169.315 Ventilation (other than machinery spaces). (a) All enclosed spaces within the vessel must be properly...

2012-10-01

326

46 CFR 127.250 - Ventilation for enclosed spaces.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 false Ventilation for enclosed spaces. 127.250 Section 127.250 Shipping ...Arrangements § 127.250 Ventilation for enclosed spaces. (a) Each enclosed space within the vessel must be properly vented...

2012-10-01

327

Wind Data for Building Ventilation in Selected US Cities.  

National Technical Information Service (NTIS)

Appropriately using natural ventilation in a building can play a significant role in reducing the building's energy consumption. However, without accurate wind velocity and direction data the designer has no chance of incorporating natural ventilation. Wi...

C. L. Robbins K. C. Hunter

1983-01-01

328

Elective ventilation for organ donation: law, policy and public ethics.  

PubMed

This paper examines questions concerning elective ventilation, contextualised within English law and policy. It presents the general debate with reference both to the Exeter Protocol on elective ventilation, and the considerable developments in legal principle since the time that that protocol was declared to be unlawful. I distinguish different aspects of what might be labelled elective ventilation policies under the following four headings: 'basic elective ventilation'; 'epistemically complex elective ventilation'; 'practically complex elective ventilation'; and 'epistemically and practically complex elective ventilation'. I give a legal analysis of each. In concluding remarks on their potential practical viability, I emphasise the importance not just of ascertaining the legal and ethical acceptability of these and other forms of elective ventilation, but also of assessing their professional and political acceptability. This importance relates both to the successful implementation of the individual practices, and to guarding against possible harmful effects in the wider efforts to increase the rates of posthumous organ donation. PMID:23222143

Coggon, John

2012-12-07

329

30 CFR 77.1106 - Battery-charging stations; ventilation.  

Code of Federal Regulations, 2013 CFR

... 2013-07-01 2013-07-01 false Battery-charging stations; ventilation. 77...COAL MINES Fire Protection § 77.1106 Battery-charging stations; ventilation. Battery-charging stations shall be located in...

2013-07-01

330

Why We Ventilate Our Houses: An Historical Look.  

National Technical Information Service (NTIS)

The knowledge of how to ventilate buildings, and how much ventilation is necessary for human health and comfort, has evolved over centuries of trial and error. Humans and animals have developed successful solutions to the problems of regulating temperatur...

N. E. Matson M. H. Sherman

2004-01-01

331

46 CFR 171.118 - Automatic ventilators and side ports.  

Code of Federal Regulations, 2011 CFR

...STABILITY SPECIAL RULES PERTAINING TO VESSELS CARRYING PASSENGERS Openings in the Side of a Vessel Below the Bulkhead or Weather Deck § 171.118 Automatic ventilators and side ports. (a) An automatic ventilator must not be fitted in the...

2011-10-01

332

46 CFR 171.118 - Automatic ventilators and side ports.  

Code of Federal Regulations, 2012 CFR

...STABILITY SPECIAL RULES PERTAINING TO VESSELS CARRYING PASSENGERS Openings in the Side of a Vessel Below the Bulkhead or Weather Deck § 171.118 Automatic ventilators and side ports. (a) An automatic ventilator must not be fitted in the...

2012-10-01

333

End of Life Choices - Feeding Tubes and Ventilators  

MedlinePLUS

... hand using a syringe or by using a machine that will drip the liquid through the tube ... of the possible treatments involves a ventilator, a machine that helps the person breathe. A ventilator requires ...

334

30 CFR 56.14213 - Ventilation and shielding for welding.  

Code of Federal Regulations, 2010 CFR

... 2009-07-01 2009-07-01 false Ventilation and shielding for welding. 56.14213 Section 56.14213 Mineral...and Operational Procedures § 56.14213 Ventilation and shielding for welding. (a) Welding operations shall be...

2009-07-01

335

30 CFR 57.14213 - Ventilation and shielding for welding.  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 2010-07-01 false Ventilation and shielding for welding. 57.14213 Section 57.14213 Mineral...and Operational Procedures § 57.14213 Ventilation and shielding for welding. (a) Welding operations shall be...

2010-07-01

336

30 CFR 57.14213 - Ventilation and shielding for welding.  

Code of Federal Regulations, 2010 CFR

... 2009-07-01 2009-07-01 false Ventilation and shielding for welding. 57.14213 Section 57.14213 Mineral...and Operational Procedures § 57.14213 Ventilation and shielding for welding. (a) Welding operations shall be...

2009-07-01

337

30 CFR 56.14213 - Ventilation and shielding for welding.  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 2010-07-01 false Ventilation and shielding for welding. 56.14213 Section 56.14213 Mineral...and Operational Procedures § 56.14213 Ventilation and shielding for welding. (a) Welding operations shall be...

2010-07-01

338

Displacement Ventilation-Dimensioning of Supply Air Flow.  

National Technical Information Service (NTIS)

A supply air flow dimensioning guide for spaces equipped with displacement ventilation systems has been developed in this research. The guide's basic data consists of the internal heat load properties of the ventilated space. The supply air flow provided ...

M. Tapola K. Koivula

1989-01-01

339

VENTILATION RESEARCH: A REVIEW OF RECENT INDOOR AIR QUALITY LITERATURE  

EPA Science Inventory

The report gives results of a literature review, conducted to survey and summarize recent and ongoing engineering research into building ventilation, air exchange rate, pollutant distribution and dispersion, and other effects of heating, ventilation, and air-conditioning (HVAC) s...

340

Uneven distribution of ventilation in acute respiratory distress syndrome  

Microsoft Academic Search

INTRODUCTION: The aim of this study was to assess the volume of gas being poorly ventilated or non-ventilated within the lungs of patients treated with mechanical ventilation and suffering from acute respiratory distress syndrome (ARDS). METHODS: A prospective, descriptive study was performed of 25 sedated and paralysed ARDS patients, mechanically ventilated with a positive end-expiratory pressure (PEEP) of 5 cmH2O

Christian Rylander; Ulf Tylén; Rauni Rossi-Norrlund; Peter Herrmann; Michael Quintel; Björn Bake

2005-01-01

341

Basics of mechanical ventilation for dogs and cats.  

PubMed

Respiratory failure may occur due to hypoventilation or hypoxemia. Regardless of the cause, emergent anesthesia and intubation, accompanied by positive pressure ventilation, may be necessary and life saving. Long-term mechanical ventilation requires some specialized equipment and knowledge; however, short-term ventilation can be accomplished without the use of an intensive care unit ventilator, and can provide oxygen supplementation and carbon dioxide removal in critical patients. PMID:23747268

Hopper, Kate; Powell, Lisa L

2013-04-29

342

Bilevel positive airway pressure ventilation: factors influencing carbon dioxide rebreathing  

Microsoft Academic Search

Purpose  Use of bilevel positive airway pressure (BLPAP) ventilators for noninvasive ventilation (NIV) is an established treatment\\u000a for both acute and chronic ventilatory failure. Although BLPAP ventilator circuits are simpler than those of conventional\\u000a ventilators, one drawback to their use is that they allow variable amounts of rebreathing to occur. The aim of this work is\\u000a to measure the amount of

Zbigniew Szkulmowski; Kheirallah Belkhouja; Quoc-Hung Le; Dominique Robert; Laurent Argaud

2010-01-01

343

Distillation pressure control  

SciTech Connect

This patent describes an apparatus comprising: a fractional distillation column; means for providing a feed mixture to be fractionated to the column; means for withdrawing an overhead vapor stream from the column; means for condensing at least a portion of the overhead vapor stream; an accumulator; means for passing the resulting at least partially condensed overhead stream into the accumulator; means for withdrawing condensate from the accumulator and for passing a first portion of the thus withdrawn condensate into an upper portion of the column as an external reflux therefore and for passing a second portion of the thus withdrawn condensate as an overhead liquid product stream; means for withdrawing a first vapor stream from the accumulator and for passing a first portion of the thus withdrawn vapor through a first control valve to a vapor recovery unit and for passing a second portion of the thus withdrawn vapor stream through a second control valve to a waste gas disposal unit; means for providing a second vapor stream from an external source to the column through a third control valve wherein the second vapor stream is compatible with the first vapor stream.

Hofferber, J.A.

1988-09-06

344

46 CFR 190.15-10 - Ventilation for closed spaces.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false Ventilation for closed spaces. 190.15-10 Section 190.15-10 Shipping...Ventilation § 190.15-10 Ventilation for closed spaces. (a) All enclosed spaces within the vessel shall be properly vented...

2011-10-01

345

46 CFR 72.15-15 - Ventilation for closed spaces.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 false Ventilation for closed spaces. 72.15-15 Section 72.15-15 Shipping...Ventilation § 72.15-15 Ventilation for closed spaces. (a) All enclosed spaces within the vessel shall be properly vented...

2012-10-01

346

46 CFR 190.15-10 - Ventilation for closed spaces.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 false Ventilation for closed spaces. 190.15-10 Section 190.15-10 Shipping...Ventilation § 190.15-10 Ventilation for closed spaces. (a) All enclosed spaces within the vessel shall be properly vented...

2012-10-01

347

46 CFR 72.15-15 - Ventilation for closed spaces.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false Ventilation for closed spaces. 72.15-15 Section 72.15-15 Shipping...Ventilation § 72.15-15 Ventilation for closed spaces. (a) All enclosed spaces within the vessel shall be properly vented...

2011-10-01

348

Non-invasive ventilation for acute respiratory disease  

Microsoft Academic Search

Non-invasive ventilation (NIV) has been shown to be effective in acute respiratory failure of various aetiologies in different health care systems and ward settings. It should be seen as complementary to invasive ventilation and primarily a means of preventing some patients from deteriorating to the point at which intubation is needed. Generally it is best initiated early before assisted ventilation

M. W. Elliott

2005-01-01

349

Non-invasive ventilation in the weaning process  

Microsoft Academic Search

Patients with chronic airflow obstruction and difficulty in weaning from mechanical ventilation are at increased risk for intubation-associated complications and mortality because of prolonged invasive mechanical ventilation. Non- invasive ventilation (NIV) may avert most of the pathophysiologic mechanisms associated with weaning failure in these patients. Several randomised controlled trials have shown that the use of NIV in order to advance

M. FERRER

350

Animal model of unilateral ventilator-induced lung injury  

Microsoft Academic Search

Objective: To design, im- plement, and test a selective lung ventilator for setting a rat model of unilateral ventilator-induced lung in- jury (VILI). Design and setting: In- terventional animal study in a uni- versity laboratory for animal re- search. Subjects: Anesthetized and paralyzed male Wistar rats. Inter- ventions: A selective ventilator de- signed to apply varying tidal volume, PEEP, and

Ramon Farre; Susana Granell; Mar Rotger; Anna Serrano-Mollar; Daniel Closa; Daniel Navajas

2005-01-01

351

COMPARISON OF DIFFERENT VENTILATION SYSTEMS FOR COMMERCIAL AIRCRAFT CABINS  

Microsoft Academic Search

The ventilation systems in commercial aircraft cabins are important for providing a healthy and comfortable environment for the passengers and crew. The mixing ventilation system currently used provides a uniform air temperature distribution and dilutes contaminants in the cabin. However, the mixing ventilation system could spread infectious airborne diseases such as influenza and SARS. It is therefore necessary to improve

T Zhang; Q Chen

2005-01-01

352

Breathing pattern and cost of ventilation in the american alligator  

Microsoft Academic Search

The energetic cost of pulmonary ventilation is termed the “cost of breathing” and is commonly determined from the change in oxygen uptake with altered ventilation. Previous analyses of lung mechanics predicts increased tidal volume would be more expensive than increased breathing frequency. Existing studies on the oxidative cost of breathing have, however, not addressed breathing pattern. We stimulated ventilation in

Tobias Wang; Stephen J. Warburton

1995-01-01

353

Solar chimney for promoting cooling ventilation in southern Algeria  

Microsoft Academic Search

In hot climates ventilation can be a useful means of cooling dwellings, if the outside air is cooler than that inside the dwelling. Often, in hot regions the outside air is so hot during the day that cooling by ventilation is of no benefit until the evening when the outside air cools. Ventilation can then be beneficial, and can be

A. Bouchair

1994-01-01

354

Modeling deposition of particles in typical horizontal ventilation duct flows  

Microsoft Academic Search

Particles carried by airflows through ventilation ducts in heating, ventilation and air-conditioning (HVAC) systems have adverse effects on human health. Knowledge of particle deposition rates in ventilation ducts is useful for modeling exposures to particles within buildings and more completely understanding particle fates. To meet these objectives, deposition rates of particles to various internal surfaces in a smooth horizontal square

Jinping Zhang; Angui Li; Desheng Li

2008-01-01

355

Ventilator-associated pneumonia: Clinical significance and implications for nursing  

Microsoft Academic Search

Pneumonia is the second most common nosocomial infection in the United States and the leading cause of death from nosocomial infections. Intubation and mechanical ventilation greatly increase the risk of bacterial pneumonia. Ventilator-associated pneumonia (VAP) occurs in a patient treated with mechanical ventilation, and it is neither present nor developing at the time of intubation; it is a serious problem—with

Mary Jo Grap; Cindy L. Munro

1997-01-01

356

Respiratory pattern, thoracoabdominal motion and ventilation in chronic airway obstruction  

Microsoft Academic Search

Respiratory pattern, thoracoabdominal motion and ventilation in chronic airway obstruction. M. Fernandes, A. Cukier, N. Ambrosino, J.J. Leite, M.I. Zanetti Feltrim. Background. Patients with chronic obstructive pul- monary disease (COPD) present abnormal respiratory mechanics, but its relation to ventilation variables at rest is not fully understood. Methods. We evaluated breathing pattern, thoracoab- dominal motion, and ventilation in moderate and severe

M. Fernandes; A. Cukier; N. Ambrosino; J. J. Leite; M. I. Zanetti Feltrim

2007-01-01

357

Experimental study on a chair-based personalized ventilation system  

Microsoft Academic Search

Personalized ventilation is expected to improve the quality of inhaled air and accommodate individual thermal preferences. In this paper, a chair-based personalized ventilation system is proposed that can potentially be applied in theatres, cinemas, lecture halls, aircrafts, and even offices. Air quality, thermal comfort, and the human response to this ventilation method were investigated by experiments. By comparing eight different

Jianlei Niu; Naiping Gao; Ma Phoebe; Zuo Huigang

2007-01-01

358

INFLUENCE OF AN INSECT SCREEN ON GREENHOUSE VENTILATION  

Microsoft Academic Search

The influence of an insect screen on ventilation rate was experimentally investigated in a multispan glass-covered greenhouse equipped with a continuous roof vent, located at the University of Thessaly near Volos in the coastal area of eastern Greece. Microclimate variables as well as the ventilation rate were measured during summer. Two measuring techniques were used for the determination of ventilation

C. Kittas; T. Boulard; T. Bartzanas; N. Katsoulas; M. Mermier

359

Greenhouse Ventilation Rate: Theory and Measurement with Tracer Gas Techniques  

Microsoft Academic Search

Leakage and ventilation rates were measured in a four span glasshouse at Silsoe Research Institute. Two tracer gas techniques were used, a decay rate method with different positions of the leeward ventilator (0, 10 and 20% of the maximum opening) and a continuous injection method with the leeward ventilators open 10%. The influences of wind speed, wind direction and temperature

F. J. Baptista; B. J. Bailey; J. M. Randall; J. F. Meneses

1999-01-01

360

Study of Mine Fires and Mine Ventilation. Part I. Computer Simulation of Ventilation Systems under the Influence of Mine Fires.  

National Technical Information Service (NTIS)

An existing computer program for mine ventilation network is modified so that it can simulate ventilation conditions under the influence of mine fires. New program parts considered are methane productions in coal mines, heat and gas productions of mine fi...

R. E. Greuer

1977-01-01

361

Imposed Work of Breathing and Breathing Comfort of Nonintubated Volunteers Breathing with Three Portable Ventilators and a Critical Care Ventilator.  

National Technical Information Service (NTIS)

In spontaneous breathing modes, past laboratory work using a lung model indicated portable ventilators as compared to critical care ventilators may increase inspiratory work of breathing. The purpose of this study was to assess the imposed inspiratory wor...

P. N. Austin

2001-01-01

362

High-frequency percussive ventilation using the VDR-4 ventilator: an effective strategy for patients with refractory hypoxemia.  

PubMed

High-frequency percussive ventilation (HFPV) has been used for patients with severe respiratory compromise refractory to conventional mechanical ventilation. It frequently results in equivalent or improved oxygenation and ventilation at lower peak pressures than conventional ventilation, thus minimizing secondary ventilator-associated lung injury. The only ventilator currently available that delivers HFPV is the volume diffusive respirator (VDR-4; Percussionaire Corp, Sandpoint, Idaho). High-frequency percussive ventilation is delivered via a pneumatically powered, pressure-limited, time-cycled, high-frequency flow interrupter and provides small tidal volumes with 300 to 700 oscillations per minute. Following transition to HFPV, respiratory status often stabilizes or improves within a few hours. The unique gas flow mobilizes significant volumes of pulmonary secretions, further facilitating gas exchange. This article reviews the operating principles of HFPV, the functional components of the VDR-4, and the special nursing care considerations to include sedation, hemodynamic assessment, skin and oral care, nutrition, and weaning from ventilation. PMID:23095962

Kunugiyama, Sujen K; Schulman, Christine S

363

Long term mechanical ventilation equipment for neuromuscular patients: meeting the expectations of patients and prescribers.  

PubMed

BACKGROUND: To maximise the likelihood of successful long term mechanical ventilation (MV) in patients with neuromuscular diseases, ventilators characteristics and settings must be chosen carefully taking into account both medical requisites and the patient's preference and comfort. The general objectives of the survey were 1) to evaluate patients comfort with, and knowledge about, their long term MV; 2) to compare patients and prescribers opinions and expectations regarding long term MV; 3) to compare the equipment used by the patients with prescribers present opinion. METHODS: Neuromuscular patients receiving long term MV and home MV prescribers in Belgium and France and MV prescribers were asked to respond to a questionnaire survey specifically developed for the study. RESULTS: Completed questionnaires were collected from 209 patients, mean age 35.4±15.9 years (range 3 to 86 years), ventilated since 11 ± 17 year, and 45 MV prescribers. Hundred sixty three (78%) patients correctly designed their MV mode as a volume or a pressure targeted mode and 86% considered their MV as "efficient". When an inspiratory trigger was available, 92% of the patients were able to use it but only 72% were satisfied. Prescribers were more prone than patients to use new technologies, such as an emergency system to release a noninvasive interface (visual analogue scale (VAS/10): 9.2±1.5 vs 6.8±3.3, P=0.0001), a humidification system (VAS: 8.6±1.4 vs 7.8±2.6, P=0.02), a contactor for providing larger inspiratory volumes (VAS: 8.4±1.7 vs 6.0±3.0, P=0.009), an in-built cough assistance mode (VAS: 9.2±1.4 vs 5.5±3.3 P=0.00001), new options to improve speech, or new MV modes such as a volume targeted-pressure controlled mode. CONCLUSIONS: Patient's and prescriber's opinion differ about the ideal home ventilator. Patients are less prone to use new technologies, mainly because of a lack of information, underlining the need of regular MV update in patients receiving long term MV. PMID:23764860

Lofaso, Frédéric; Prigent, Hélène; Tiffreau, Vincent; Menoury, Nathalie; Toussaint, Michel; Finet Monnier, Armelle; Stremler, Natalie; Devaux, Christian; Leroux, Karl; Orlikowski, David; Mauri, Cécile; Pin, Isabelle; Sacconi, Sabrina; Pereira, Cécile; Pépin, Jean-Louis; Fauroux, Brigitte

2013-06-13

364

Project Design Concept Primary Ventilation System  

Microsoft Academic Search

Tank Farm Restoration and Safe Operation (TFRSO), Project W-3 14 was established to provide upgrades that would improve the reliability and extend the system life of portions of the waste transfer, electrical, ventilation, instrumentation and control systems for the Hanford Site Tank Farms. An assessment of the tank farm system was conducted and the results are documented in system assessment

2000-01-01

365

Percutaneous tracheostomy in the ventilated patient.  

PubMed

The medical indications of tracheostomy comprise the alleviation of upper airway obstruction; the prevention of laryngeal and upper airway damage due to prolonged translaryngeal intubation in patients subjected to prolonged mechanical ventilation; and the facilitation of airway access for the removal of secretions. Since 1985, percutaneous tracheostomy (PT) has gained widespread acceptance as a method for creating a surgical airway in patients requiring long-term mechanical ventilation. Since then, several comparative trials of PT and surgical tracheostomy have been conducted, and new techniques for PT have been developed. The use of percutaneous dilatation techniques under bronchoscopic control are now increasingly popular throughout the world. Tracheostomy should be performed as soon as the need for prolonged intubation is identified. However a validated model for the prediction of prolonged mechanical ventilation is not available, and the timing of tracheostomy should be individualized. The present review analyzes the state of the art of PT in mechanically ventilated patients - this being regarded by many as the technique of choice in performing tracheostomy in critically ill patients. PMID:23347906

Añón, J M; Araujo, J B; Escuela, M P; González-Higueras, E

2013-01-21

366

Modeling particle loss in ventilation ducts  

SciTech Connect

Empirical equations were developed and applied to predict losses of 0.01-100 {micro}m airborne particles making a single pass through 120 different ventilation duct runs typical of those found in mid-sized office buildings. For all duct runs, losses were negligible for submicron particles and nearly complete for particles larger than 50 {micro}m. The 50th percentile cut-point diameters were 15 {micro}m in supply runs and 25 {micro}m in return runs. Losses in supply duct runs were higher than in return duct runs, mostly because internal insulation was present in portions of supply duct runs, but absent from return duct runs. Single-pass equations for particle loss in duct runs were combined with models for predicting ventilation system filtration efficiency and particle deposition to indoor surfaces to evaluate the fates of particles of indoor and outdoor origin in an archetypal mechanically ventilated building. Results suggest that duct losses are a minor influence for determining indoor concentrations for most particle sizes. Losses in ducts were of a comparable magnitude to indoor surface losses for most particle sizes. For outdoor air drawn into an unfiltered ventilation system, most particles smaller than 1 {micro}m are exhausted from the building. Large particles deposit within the building, mostly in supply ducts or on indoor surfaces. When filters are present, most particles are either filtered or exhausted. The fates of particles generated indoors follow similar trends as outdoor particles drawn into the building.

Sippola, Mark R.; Nazaroff, William W.

2003-04-01

367

Anxiety and Agitation in Mechanically Ventilated Patients  

PubMed Central

During an ethnography conducted in an intensive care unit (ICU), we found that anxiety and agitation occurred frequently, and were important considerations in the care of 30 patients weaning from prolonged mechanical ventilation. We conducted a secondary analysis to (a) describe characteristics of anxiety and agitation experienced by mechanically ventilated patients; (b) explore how clinicians recognize and interpret anxiety and agitation and (c) describe strategies and interventions used to manage anxiety and agitation with mechanically ventilated patients. We constructed the Anxiety-Agitation in Mechanical Ventilation Model to illustrate the multidimensional features of symptom recognition and management. Patients’ ability to interact with the environment served as a basis for identification and management of anxiety or agitation. Clinicians’ attributions about anxiety or agitation and “knowing the patient” contributed to their assessment of patient responses. Clinicians chose strategies to overcome either the stimulus or patient’s appraisal of risk of the stimulus. This article contributes to the body of knowledge about symptom recognition and management in the ICU by providing a comprehensive model to guide future research and practice.

Tate, Judith Ann; Dabbs, Annette Devito; Hoffman, Leslie; Milbrandt, Eric; Happ, Mary Beth

2013-01-01

368

Lung function testing — useless in ventilated newborns?  

Microsoft Academic Search

Several methods have been used for lung function testing in the ventilated newborn. The interest in the field has been stimulated by the recent appearance of commercially available equipment for assessment of mechanical parameters and of functional residual capacity in this group. Nevertheless, lung function testing is rarely used as a clinical routine, even such simple variables as tidal volume

Ola Hjalmarson

1994-01-01

369

Current issues in home mechanical ventilation.  

PubMed

As modern health care continues to evolve, we expect and are seeing that more sophisticated medical care will be provided outside the traditional acute care environments. Advances in home medical technology, economic pressures, health-care consumerism, and societal changes are all factors playing a role in this evolution. Medically fragile and technology-dependent individuals who were once limited to care in acute and subacute institutional settings are now frequently cared for at home, most often by their immediate family members. Mechanical ventilation has found its way into the patient's home such that physicians and other providers must be prepared for the challenges associated with managing the conditions of complex, ventilator-dependent individuals outside of the walls, controls, and safety of the institutional setting. With little published science and recognized standards of practice, there are fewer rules to guide clinicians through this process. Experience has shown, however, that successful home management of ventilator-dependent individuals can be traced to a smooth and collaborative discharge from the hospital to home. Reimbursement and coverage issues must also be well understood to avoid the aggravation of denials and challenges for necessary equipment and assistance. Once home, a streamlined, patient-centered process supported by effective communication between all care providers can result in a safe and appropriate long-term home ventilation success story. PMID:17699139

Lewarski, Joseph S; Gay, Peter C

2007-08-01

370

46 CFR 168.15-50 - Ventilation.  

Code of Federal Regulations, 2011 CFR

...purpose of the space and route of the vessel. (b) When mechanical ventilation is provided for sleeping rooms, washrooms, toilet rooms, hospital spaces, and messrooms, these spaces must be supplied with fresh air equal to at least 10 times the volume...

2011-10-01

371

A Medical Student Workshop in Mechanical Ventilation.  

ERIC Educational Resources Information Center

|In order to teach applied respiratory physiology to medical students, the anesthesiology faculty at the University of Florida College of Medicine has designed and implemented a course that includes a laboratory workshop in mechanical ventilation of an animal model that allows students to apply and expand their knowledge. (JMD)|

And Others; Kushins, Lawrence G.

1980-01-01

372

Dehumidification and cooling loads from ventilation air  

Microsoft Academic Search

Ninety-five years since Willis Carrier began the modern era of air-conditioning by dehumidifying a printing plant, industry is becoming more concerned with the importance of controlling humidity in buildings. In part, this concern stems from indoor air quality problems associated with excess moisture in AC systems. But more universally, the need for ventilation air has forced HVAC equipment originally optimized

Lewis G. Harriman; Dean Plager; Douglas Kosar

1999-01-01

373

Limitations of jet ventilation through the laryngoscope.  

PubMed

A series is presented of 100 patients who underwent direct laryngoscopy under general anaesthesia. Our preferred technique of ventilation is jet insufflation by an injector attached to the blade of the laryngoscope, as it provides the surgeon with a quiet and completely exposed larynx. In nine cases, chest expansion was assessed as inadequate by the anaesthetist. These patients were obese with a short neck, and/or stiff-necked; thus, insertion of the laryngoscope was difficult and a good seal between it and the larynx could not be achieved. Arterial blood gas values in six of these patients demonstrated marked hypoventilation. To improve ventilation in these patients an alternative technique of insufflation through a nasotracheal catheter was used. Arterial blood gas values indicated that this method resolved the problem of hypoventilation. Although the catheter somewhat limits the view of the endolarynx, the improved ventilation outweighs the drawbacks of this technique. It is suggested that for the obese and/or stiff-necked patient, a nasotracheal catheter be used electively for ventilation. PMID:6802468

Winerman, I; Ezra, S; Man, A; Segal, S

1982-03-01

374

Noninvasive Home Mechanical Ventilation in Elderly Patients  

Microsoft Academic Search

Study Objective: To determine the short- and long-term benefits of noninvasive home mechanical ventilation (NIHMV) in patients aged 65 and older who were eligible for this treatment. Design and Setting: This retrospective, comparative, longitudinal study was carried out in a tertiary care hospital in Barcelona (Spain). Patients and Methods: The study included all patients in whom NIHMV with a nasal

Astrid Crespo; Xavier Muñoz; Ferran Torres; Sergi Martí; Jaume Ferrer; Ferran Morell

2010-01-01

375

Noninvasive mechanical ventilation in acute respiratory failure  

Microsoft Academic Search

Mechanical ventilation (MV) has been indicated in the treatment of acute respiratory failure (ARF) if conservative treatment fails. Invasive MV is asso- ciated to a variety of complications. The recent innovations of noninvasive methods of MV (NMV) avoid the complications of invasive MV, whilst ensuring a similar degree of efficacy. A review of the literature from 1989 to 1995 shows

N. Ambrosino

1996-01-01

376

14 CFR 125.117 - Ventilation.  

Code of Federal Regulations, 2013 CFR

...SEATING CAPACITY OF 20 OR MORE PASSENGERS OR A MAXIMUM PAYLOAD CAPACITY...117 Ventilation. Each passenger or crew compartment must...other means allowing air to flow between compartments, there...to the crew for closing the flow of air through the...

2013-01-01

377

14 CFR 121.219 - Ventilation.  

Code of Federal Regulations, 2013 CFR

...Requirements § 121.219 Ventilation. Each passenger or crew compartment must be suitably...louvres or other means allowing air to flow between compartments, there must be a means convenient to the crew for closing the flow of air through the partitions, when...

2013-01-01

378

Ventilation index of helicopter pilot suits  

Microsoft Academic Search

The main function of helicopter pilot suits used in offshore flights is to provide thermal protection in the event of cold water immersion and to allow maintenance of thermal comfort during normal use. As part of a larger study to assess the thermal characteristics of helicopter pilot suits, the ventilation index of four suits was determined using the methods outlined

PATRICK J. SULLIVAN; IGOR B. MEKJAVIC; NAOSHI KAKITSUBA

1987-01-01

379

Project Design Concept Primary Ventilation System  

SciTech Connect

Tank Farm Restoration and Safe Operation (TFRSO), Project W-3 14 was established to provide upgrades that would improve the reliability and extend the system life of portions of the waste transfer, electrical, ventilation, instrumentation and control systems for the Hanford Site Tank Farms. An assessment of the tank farm system was conducted and the results are documented in system assessment reports. Based on the deficiencies identified in the tank farm system assessment reports, and additional requirements analysis performed in support of the River Protection Project (RPP), an approved scope for the TFRSO effort was developed and documented in the Upgrade Scope Summary Report (USSR), WHC-SD-W314-RPT-003, Rev. 4. The USSR establishes the need for the upgrades and identifies the specific equipment to be addressed by this project. This Project Design Concept (PDC) is in support of the Phase 2 upgrades and provides an overall description of the operations concept for the W-314 Primary Ventilation Systems. Actual specifications, test requirements, and procedures are not included in this PDC. The PDC is a ''living'' document, which will be updated throughout the design development process to provide a progressively more detailed description of the W-314 Primary Ventilation Systems design. The Phase 2 upgrades to the Primary Ventilation Systems shall ensure that the applicable current requirements are met for: Regulatory Compliance; Safety; Mission Requirements; Reliability; and Operational Requirements.

MCGREW, D.L.

2000-10-02

380

MODELING EXISTING VENTILATION SYSTEMS USING MEASURED VALUES  

Microsoft Academic Search

Equations are derived to model installed exhaust ventilation systems using measured diameters, flows, and pressures. The system of equations does not require knowledge of system components or their loss coefficients except for those components that will be replaced. The approach also allows detection of physical changes in existing systems. Measurement errors limit the accuracy of predictions. The nonquadratic relationship between

Steven E. Guffey

1993-01-01

381

Buoyancy-Affected Flows in Ventilated Rooms  

Microsoft Academic Search

Calculations of velocity and temperature distributions in rooms with ventilation arrangements are reported. The method involves the solution, in finite-difference form, of two-dimensional equations for the conservation of mass, momentum, energy, turbulence energy, and dissipation rate, with algebraic expressions for the turbulent viscosity and heat diffusivity. The results are shown to be in reasonable agreement with available experimental data and

P. V. Nielsen; A. Restivo; J. H. Whitelaw

1979-01-01

382

Fire Protection Countermeasures for Containment Ventilation Systems.  

National Technical Information Service (NTIS)

The goal of this project is to find countermeasures to protect HEPA filters in exit ventilation ducts from the heat and smoke generated by fire. Several methods for partially mitigating the smoke exposure to the HEPA filters were identified through testin...

N. J. Alvares D. G. Beason W. Bergman H. W. Ford A. E. Lipska

1980-01-01

383

A Medical Student Workshop in Mechanical Ventilation.  

ERIC Educational Resources Information Center

In order to teach applied respiratory physiology to medical students, the anesthesiology faculty at the University of Florida College of Medicine has designed and implemented a course that includes a laboratory workshop in mechanical ventilation of an animal model that allows students to apply and expand their knowledge. (JMD)

And Others; Kushins, Lawrence G.

1980-01-01

384

Inefficiency of upward displacement operating theatre ventilation.  

PubMed

A new thermally based ventilation system ('Floormaster') with inlet of cool clean air at floor level, and evacuation at the ceiling of the air warmed by activity in the room (upward displacement ventilation, 17 air changes/h) was compared with a standard positive pressure (plenum) ventilation system with air supply through an inclined perforated screen along one wall at the ceiling and evacuation at floor level (conventional turbulent or mixing system, 16 air changes/h). The study was made during rigidly standardized sham operations (N = 20) performed in the same operating room by a six-member team wearing non-woven disposable or cotton clothing. In general the upward displacement system removed dust particles too small to carry bacteria (0.16-<0.3 microm, 0.001ventilation systems. PMID:8999051

Friberg, B; Friberg, S; Burman, L G; Lundholm, R; Ostensson, R

1996-08-01

385

Does Mixing Make Residential Ventilation More Effective?  

SciTech Connect

Ventilation dilutes or removes indoor contaminants to reduce occupant exposure. In a multi-zone environment such as a house, there will be different dilution rates and different source strengths in every zone. The total ventilation rate is the most important factor in determining the exposure of occupants to given sources, but the zone- specific distribution of exhaust and supply air, and the mixing of ventilation air can have significant roles. Different types of ventilation systems will provide different amounts of mixing depending on several factors such as air leakage through the building envelope, air distribution systems and the location of sources and occupants. This paper reports recent results of investigations to determine the impact that air mixing has on exposures of residential occupants to prototypical contaminants of concern. Evaluations of existing field measurements and simulations reported in the literature are combined with new analyses to provide an integrated overview of the topic. The results show that for extreme cases additional mixing can be a significant factor but for typical homes looking at average exposures mixing is not helpful and can even make exposures worse.

Sherman, Max; Walker, Iain

2010-08-16

386

Teaching Alveolar Ventilation with Simple, Inexpensive Models  

ERIC Educational Resources Information Center

|When teaching and learning about alveolar ventilation with our class of 300 first-year medical students, we use four simple, inexpensive "models." The models, which encourage research-oriented learning and help our students to understand complex ideas, are distributed to the students before class. The students anticipate something new every day,…

DiCarlo, Stephen E.

2008-01-01

387

Tunnel ventilation system design and management  

Technology Transfer Automated Retrieval System (TEKTRAN)

Properly designed and functioning tunnel ventilation systems in broiler houses are essential for maintaining productivity of broilers in warm weather. Convective heat loss from high air velocity provides cooling which improves performance; however, high air velocities require larger fans and increa...

388

Including Children Dependent on Ventilators in School.  

ERIC Educational Resources Information Center

|Guidelines for including ventilator-dependent children in school are offered, based on experience with six such students at a New York State school. Guidelines stress adherence to the medical management plan, the school-family partnership, roles of the social worker and psychologist, orientation, transportation, classroom issues, and steps toward…

Levine, Jack M.

1996-01-01

389

46 CFR 194.10-25 - Ventilation.  

Code of Federal Regulations, 2012 CFR

...VESSELS HANDLING, USE, AND CONTROL OF EXPLOSIVES AND OTHER HAZARDOUS...below 100 °F. with 88 °F. weather air. Mechanical cooling...shall serve no other space. Weather cowls shall be provided with... (2) Ventilation supply weather openings shall be...

2012-10-01

390

46 CFR 194.10-25 - Ventilation.  

Code of Federal Regulations, 2011 CFR

...VESSELS HANDLING, USE, AND CONTROL OF EXPLOSIVES AND OTHER HAZARDOUS...below 100 °F. with 88 °F. weather air. Mechanical cooling...shall serve no other space. Weather cowls shall be provided with... (2) Ventilation supply weather openings shall be...

2011-10-01

391

VENTILATING HORNETS DISPLAY DIFFERENTIAL BODY TEMPERATURE  

Microsoft Academic Search

abdomen bent downward at a 90? angle to the thorax, their antennae vibrating, and their wings beating rapidly for minutes at a time. Eventually these hornets leave their position, either to retreat into the nest or else to fly off to the field, and are replaced by new hornets that assume the ventilation task. Infra-red (IR) photography reveals that in

Jacob S. Ishay; Marian Plotkin; Natalya Ermakov; Alon Goren; David J. Bergman

2006-01-01

392

EXPERIMENTAL STUDY OF A VENTILATED SUPERCAVITATING VEHICLE  

Microsoft Academic Search

Supercavitating vehicles need to be supplied with an artificial cavity through ventilation until they accelerate to conditions at which a natural supercavity can be sustained. A study has been carried out in the high-speed water tunnel at St. Anthony Falls Laboratory to investigate some aspects of the flow physics of such a supercavitating vehicle. Digital strobe photography images were taken

Martin Wosnik; Travis J. Schauer; Roger E. A. Arndt

393

46 CFR 194.20-5 - Ventilation.  

Code of Federal Regulations, 2011 CFR

...OTHER HAZARDOUS MATERIALS Chemical Stores and/or Storerooms...20-5 Ventilation. (a) Chemical storerooms shall be equipped...sufficient to effect a complete change of air in not more than 4...Provisions shall be made so that the chemical storeroom will be...

2011-10-01

394

46 CFR 194.20-5 - Ventilation.  

Code of Federal Regulations, 2012 CFR

...OTHER HAZARDOUS MATERIALS Chemical Stores and/or Storerooms...20-5 Ventilation. (a) Chemical storerooms shall be equipped...sufficient to effect a complete change of air in not more than 4...Provisions shall be made so that the chemical storeroom will be...

2012-10-01

395

Analysis of Night Ventilation Potential for Residen tial Buildings in Hot-Humid Climate of Malaysia  

Microsoft Academic Search

This paper discusses the potential of app lying night ventilation as a passive cooling techni que for Malaysian terraced houses based on the results of a full-scal e field experiment. The results revealed that night ventilation provides better diurnal and nocturnal air temperature reduct ions than daytime ventilation, full-day ventilation and no ventilation. Night ventilation improves thermal comfort more tha

DORIS TOE HOOI CHYEE; TETSU KUBOTA

396

Gas exchange and intrapulmonary distribution of ventilation during continuous-flow ventilation  

SciTech Connect

In 12 anesthetized paralyzed dogs, pulmonary gas exchange and intrapulmonary inspired gas distribution were compared between continuous-flow ventilation (CFV) and conventional mechanical ventilation (CMV). Nine dogs were studied while they were lying supine, and three dogs were studied while they were lying prone. A single-lumen catheter for tracheal insufflation and a double-lumen catheter for bilateral endobronchial insufflation (inspired O2 fraction = 0.4; inspired minute ventilation = 1.7 +/- 0.3 (SD) 1.kg-1.min-1) were evaluated. Intrapulmonary gas distribution was assessed from regional 133Xe clearances. In dogs lying supine, CO2 elimination was more efficient with endobronchial insufflation than with tracheal insufflation, but the alveolar-arterial O2 partial pressure difference was larger during CFV than during CMV, regardless of the type of insufflation. By contrast, endobronchial insufflation maintained both arterial PCO2 and alveolar-arterial O2 partial pressure difference at significantly lower levels in dogs lying prone than in dogs lying supine. In dogs lying supine, the dependent lung was preferentially ventilated during CMV but not during CFV. In dogs lying prone, gas distribution was uniform with both modes of ventilation. The alveolar-arterial O2 partial pressure difference during CFV in dogs lying supine was negatively correlated with the reduced ventilation of the dependent lung, which suggests that increased ventilation-perfusion mismatching was responsible for the increase in alveolar-arterial O2 partial pressure difference. The more efficient oxygenation during CFV in dogs lying prone suggests a more efficient matching of ventilation to perfusion, presumably because the distribution of blood flow is also nearly uniform.

Vettermann, J.; Brusasco, V.; Rehder, K.

1988-05-01

397

Respiratory Care year in review 2012: invasive mechanical ventilation, noninvasive ventilation, and cystic fibrosis.  

PubMed

For the busy clinician, educator, or manager, it is becoming an increasing challenge to filter the literature to what is relevant to one's practice and then update one's practice based on the current evidence. The purpose of this paper is to review the recent literature related to invasive mechanical ventilation, noninvasive ventilation, and cystic fibrosis. These topics were chosen and reviewed in a manner that is most likely to have interest to the readers of Respiratory Care. PMID:23564873

Kallet, Richard H; Volsko, Teresa A; Hess, Dean R

2013-04-01

398

Patient-ventilator asynchrony during noninvasive ventilation: the role of expiratory trigger  

Microsoft Academic Search

Objective: Air leaks around the mask are very likely to occur during noninvasive ventilation, in particular when prolonged ventilatory\\u000a treatment is required. It has been suggested that leaks from the mask may impair the expiratory trigger cycling mechanism\\u000a when inspiratory pressure support ventilation (PSV) is used. The aim of this study was to compare the short-term effect of\\u000a two different

E. Calderini; M. Confalonieri; P. G. Puccio; N. Francavilla; L. Stella; C. Gregoretti

1999-01-01

399

Noninvasive proportional assist ventilation for acute respiratory insufficiency. Comparison with pressure support ventilation.  

PubMed

Noninvasive positive pressure ventilation (NPPV) is usually applied using pressure support ventilation (PSV). Proportional assist ventilation (PAV) is a newer mode that delivers assisted ventilation in proportion to patient effort. We hypothesized that PAV for NPPV would support gas exchange and avoid intubation as well as PSV and be more comfortable and tolerable for patients. Adult patients with acute respiratory insufficiency were randomized to receive NPPV with PAV delivered using the Respironics Vision ventilator or PSV using a Puritan-Bennett 7200ae critical care ventilator. Each mode was adjusted to relieve dyspnea and improve gas exchange until patients met weaning or intubation criteria, died, or refused to continue. Twenty-one and 23 patients were entered into the PAV and PSV groups, respectively, and had similar diagnoses and baseline characteristics, although pH was slightly lower in the PAV group (7.30 versus 7.35, p = 0.02). Mortality and intubation rates were similar, but refusal rate was lower, reduction in respiratory rate was more rapid, and there were fewer complications in the PAV group. We conclude that use of the PAV mode is feasible for noninvasive therapy of acute respiratory insufficiency. Compared with PSV delivered with the Puritan-Bennett 7200ae, PAV is associated with more rapid improvements in some physiologic variables and is better tolerated. PMID:11719297

Gay, P C; Hess, D R; Hill, N S

2001-11-01

400

Social Adversity Experience and Blood Pressure Control Following Antihypertensive Medication Use in a Community Sample of Older Adults.  

PubMed

BACKGROUND: Psychosocial stress is a risk factor for hypertension and has been shown to affect response to treatment for psychiatric illnesses. PURPOSE: We investigate the relationship between a history of social adversity experience and blood pressure control following antihypertensive medication use. METHODS: A total of 1,186 participants selected from the European Prospective Investigation into Cancer-Norfolk study (531 men and 655 women, aged 42 to 80 years) had attended two health checks at which blood pressure measurements were taken; were taking antihypertensive medication at the second, but not the first health check; and had completed a questionnaire assessment of their social and psychological circumstances which included details of traumatic experiences in childhood and of adverse life events, long-term difficulties, and perceived stress in adulthood. RESULTS: Experience of recent loss events in adulthood was associated with a smaller reduction in systolic blood pressure after starting hypertension treatment (??=?1.78, 95 % confidence interval 0.15-3.40, per life event), independently of age, sex, preexisting health conditions, cigarette smoking history, alcohol consumption, physical activity, and obesity. CONCLUSION: Results from this study suggest that stress caused by recent losses may be associated with reduced effectiveness of treatment for hypertension. Subject to replication, these findings may help determine the specific physiological mechanisms by which medication treatment effectiveness is affected by stress. PMID:23677855

Wainwright, Nicholas Wj; Levy, Sheldon; Pico, Jose; Luben, Robert N; Surtees, Paul G; Khaw, Kay-Tee

2013-05-16

401

On The Valuation of Infiltration towards Meeting Residential Ventilation Needs  

SciTech Connect

The purpose of ventilation is dilute or remove indoor contaminants that an occupant is exposed to. It can be provided by mechanical or natural means. In most homes, especially existing homes, infiltration provides the dominant fraction of the ventilation. As we seek to provide acceptable indoor air quality at minimum energy cost, it is important to neither over-ventilate nor under-ventilate. Thus, it becomes critically important to correctly evaluate the contribution infiltration makes to both energy consumption and equivalent ventilation. ASHRAE Standards including standards 62, 119, and 136 have all considered the contribution of infiltration in various ways, using methods and data from 20 years ago.

Sherman, Max H.

2008-09-01

402

SY Tank Farm ventilation isolation option risk assessment report  

SciTech Connect

The safety of the 241-SY Tank Farm ventilation system has been under extensive scrutiny due to safety concerns associated with tank 101-SY. Hydrogen and other gases are generated and trapped in the waste below the liquid surface. Periodically, these gases are released into the dome space and vented through the exhaust system. This attention to the ventilation system has resulted in the development of several alternative ventilation system designs. The ventilation system provides the primary means of mitigation of accidents associated with flammable gases. This report provides an assessment of various alternatives ventilation system designs.

Powers, T.B.; Morales, S.D.

1994-03-01

403

[Interpretation of ventilator curves in patients with acute respiratory failure].  

PubMed

Mechanical ventilation is a therapeutic intervention involving the temporary replacement of ventilatory function with the purpose of improving symptoms in patients with acute respiratory failure. Technological advances have facilitated the development of sophisticated ventilators for viewing and recording the respiratory waveforms, which are a valuable source of information for the clinician. The correct interpretation of these curves is crucial for the correct diagnosis and early detection of anomalies, and for understanding physiological aspects related to mechanical ventilation and patient-ventilator interaction. The present study offers a guide for the interpretation of the airway pressure and flow and volume curves of the ventilator, through the analysis of different clinical scenarios. PMID:22014424

Correger, E; Murias, G; Chacon, E; Estruga, A; Sales, B; Lopez-Aguilar, J; Montanya, J; Lucangelo, U; Garcia-Esquirol, O; Villagra, A; Villar, J; Kacmarek, R M; Burgueño, M J; Blanch, L

2011-10-19

404

Toothbrushing may reduce ventilator-associated pneumonia.  

PubMed

Data sourcesThe databases Embase, Medline, CINAHL, the Cochrane Central Register of Controlled Trials, the Cochrane Database of Systematic Reviews, clinical trials.gov and controlled-trials.com were searched. Reference lists of reviewed articles and eligible trials were also searched, and toothpaste and toothbrush manufactures were contacted.Study selectionRandomised controlled trials in adults over 18 years receiving mechanical ventilation were included where any kind of oral care involving toothbrushing was compared with any other kind of oral care or control with or without toothbrushing.Data extraction and synthesisData were extracted in duplicate and quality assessed using the Cochrane risk of bias tool. The results were combined using a random effects model. The main outcome was VAP.ResultsSix trials involving a total of 1408 patients were included. The risk of bias was high in four trials, low in one and unclear in the other. In four trials, there was a trend toward lower ventilator-associated pneumonia rates (risk ratio, 0.77; 95% confidence interval, 0.50-1.21; p = 0.26). The only trial with low risk of bias suggested that toothbrushing significantly reduced ventilator-associated pneumonia (risk ratio, 0.26; 95% confidence interval, 0.10-0.67; p = 0.006). Use of chlorhexidine antisepsis seems to attenuate the effect of toothbrushing on ventilator-associated pneumonia (p for the interaction = 0.02). One trial comparing electric vs. manual toothbrushing showed no difference in ventilator-associated pneumonia rates (risk ratio, 0.96; 95% confidence interval, 0.47-1.96; p = 0.91). Toothbrushing did not impact on length of ICU stay, or ICU or hospital mortality.ConclusionsIn summary, randomised trials to date show that toothbrushing is associated with a trend toward lower rates of VAP in intubated, mechanically ventilated critically ill patients. There is no clear difference between electric and manual toothbrushing. Toothbrushing has no effect on ICU mortality, hospital mortality, or ICU length of stay. PMID:24071681

Yusuf, Huda

2013-09-01

405

Exploring racial and sociodemographic trends in physician behavior, physician trust and their association with blood pressure control.  

PubMed

Racial disparities in several facets of healthcare have been widely documented, showing that African Americans face disproportionately high health risks when compared to whites. With respect to hypertension, 40% of the > or = 36 million African Americans are affected. We examined the correlation between the patient-physician relationship and the racial disparities in healthcare. We hypothesized that increased physician counseling would lead to higher patient trust and, thus, a greater likelihood of having controlled blood pressure. Four-hundred-sixty black and 333 white Veteran Affairs (VA) patients previously diagnosed with hypertension were included. Patients with a systolic reading > or = 140 mmHg and/or a diastolic reading > or = 90 mmHg at a recent doctor visit were considered to have uncontrolled blood pressure. By using patient exit interviews (PEIs), we quantified the number of counseling behaviors performed by physicians. Patient trust in physician was measured by validated questions answered on a 1-5 agreement scale. Results showed no racial disparity in blood pressure control. While blacks were found to receive more counseling, whites reported higher trust. Controlling for sociodemographic factors, we found that regardless of race, higher PEI scores were associated with higher trust; however, they were also associated with uncontrolled blood pressure. The association of physician behavior with blood pressure was not mediated by trust. We were unable to make direct cause-and-effect conclusions because the measures were recorded from a one-time questionnaire. Future research should focus on uncovering causal relationships, allowing physicians to work towards ending the established healthcare disparities. PMID:18020100

Rawaf, Mustafa M; Kressin, Nancy R

2007-11-01

406

Overall and Minority-Focused Recruitment Strategies in the PREMIER Multicenter Trial of Lifestyle Interventions for Blood Pressure Control  

PubMed Central

Recruitment strategies employed by four clinical centers across the US and a coordinating center were examined to identify successful overall and minority-focused recruitment strategies for the PREMIER multicenter trial of lifestyle changes for blood pressure control. The goal was to recruit 800 adults (40% African Americans) with systolic blood pressure of 120-159 mmHg and diastolic of 80-95 mmHg, not taking antihypertensive medication. Clinical centers used combinations of mass distribution of brochures, mass media, email distribution lists, screening events, and a national website. Culturally appropriate strategies for African Americans were designed by a Minority Implementation (MI) committee. Diversity training was provided for study staff, and African Americans were included in the study design process. Main recruitment outcomes were number overall and number of African Americans recruited by each strategy. Of the 810 randomized PREMIER participants, 279 (34%) were African American with site specific percentages of 56%, 46%, 27%, and 8%. Of African Americans recruited, 151 (54%) were from mass distribution of brochures (mailed letter, flyer included in Val-Pak coupons, or other), 66 (24%) from mass media (printed article, radio, TV story or ads, 52 (19%) from word of mouth, and 10 (3%) from email/website and screening events combined. Yields for Non-Hispanic Whites were 364 (69%) from brochures, 71 (13%) from mass media, 49 (9%) from word of mouth and 47 (9%) from email/website and screening events. Mass distribution of brochures was relatively more effective with Non-Hispanic Whites, while African Americans responded relatively better to other recruitment strategies.

Kennedy, Betty M.; Kumanyika, Shiriki; Ard, Jamy D.; Reams, Patrice; Johnson, Cheryl A.; Karanja, Njeri; Charleston, Jeanne B.; Appel, Lawrence J.; Maurice, Vallerie; Harsha, David W.

2009-01-01

407

Indication-specific 6-hour systolic blood pressure thresholds can approximate 24-hour determination of blood pressure control  

PubMed Central

Ambulatory blood pressure monitoring (ABPM) is an accurate method for evaluating hypertension, yet its use in clinical practice may be limited by availability, cost, and patient inconvenience. The objective of this study was to investigate the ability of a 6-hour ABPM window to predict blood pressure control, based on that of the full 24-hour ABPM session across several clinical indications in a cohort of 486 patients referred for ABPM. Sensitivities and specificities of the 6-hour systolic blood pressure mean to accurately classify patients as hypertensive were determined using a fixed reference point of 130 mmHg for the 24-hour mean. For four common indications in which ABPM was ordered, prediction tables were constructed varying the thresholds for the 6-hour mean to find the optimal value that best predicted the 24-hour hypertensive status as determined from the full 24-hour interval. Using a threshold of 137 mmHg for the indications of borderline hypertension, evaluation of current antihypertensive regimen and suspected white-coat hypertension, sensitivity and specificity ranged from 0.83–0.88 and 0.80–0.88, respectively, for the ability of 6-hour ABPM to correctly categorize hypertensive status. Using 133 mmHg as the threshold for treatment resistance resulted in a sensitivity and specificity of 0.93 and 0.83, respectively. We conclude that a shortened ABPM session of 6 hours can be used to accurately classify blood pressure as controlled or not, based on the results of a 24-hour session. The optimal 6-hour threshold for comparison depends upon indication for referral.

Ernst, Michael E.; Sezate, Genesis S.; Lin, Wenjiao; Weber, Cynthia A.; Dawson, Jeffrey D.; Carter, Barry L.; Bergus, George R.

2010-01-01

408

Exploring racial and sociodemographic trends in physician behavior, physician trust and their association with blood pressure control.  

PubMed Central

Racial disparities in several facets of healthcare have been widely documented, showing that African Americans face disproportionately high health risks when compared to whites. With respect to hypertension, 40% of the > or = 36 million African Americans are affected. We examined the correlation between the patient-physician relationship and the racial disparities in healthcare. We hypothesized that increased physician counseling would lead to higher patient trust and, thus, a greater likelihood of having controlled blood pressure. Four-hundred-sixty black and 333 white Veteran Affairs (VA) patients previously diagnosed with hypertension were included. Patients with a systolic reading > or = 140 mmHg and/or a diastolic reading > or = 90 mmHg at a recent doctor visit were considered to have uncontrolled blood pressure. By using patient exit interviews (PEIs), we quantified the number of counseling behaviors performed by physicians. Patient trust in physician was measured by validated questions answered on a 1-5 agreement scale. Results showed no racial disparity in blood pressure control. While blacks were found to receive more counseling, whites reported higher trust. Controlling for sociodemographic factors, we found that regardless of race, higher PEI scores were associated with higher trust; however, they were also associated with uncontrolled blood pressure. The association of physician behavior with blood pressure was not mediated by trust. We were unable to make direct cause-and-effect conclusions because the measures were recorded from a one-time questionnaire. Future research should focus on uncovering causal relationships, allowing physicians to work towards ending the established healthcare disparities.

Rawaf, Mustafa M.; Kressin, Nancy R.

2007-01-01

409

Technical Review Report for the Mound 1KW Package Safety Analysis Report for Packaging Waiver for the Use of Modified Primary Containment Vessel (PCV)  

SciTech Connect

This Technical Review Report (TRR) documents the review, performed by the Lawrence Livermore National Laboratory (LLNL) staff, at the request of the U.S. Department of Energy (DOE), on the Waiver for the Use of Modified Primary Containment Vessels (PCV). The waiver is to be used to support a limited number of shipments of fuel for the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) Project in support of the National Aeronautics and Space Administration's (NASA's) Mars Science Laboratory (MSL) mission. Under the waiver, an inventory of existing national security PCVs will be converted to standard PCVs. Both types of PCVs are currently approved for use by the Office of Nuclear Energy. LLNL has previously reviewed the national security PCVs under Mound 1KW Package Safety Analysis Report for Packaging, Addendum No. 1, Revision c, dated June 2007 (Addendum 1). The safety analysis of the package is documented in the Safety Analysis Report for Packaging (SARP) for the Mound 1KW Package (i.e., the Mound 1KW SARP, or the SARP) where the standard PCVs have been reviewed by LLNL. The Mound 1KW Package is certified by DOE Certificate of Compliance (CoC) number USA/9516/B(U)F-85 for the transportation of Type B quantities of plutonium heat source material. The waiver requests an exemption, claiming safety equivalent to the requirements specified in 10 CFR 71.12, Specific Exemptions, and will lead to a letter amendment to the CoC. Under the waiver, the Office of Radioisotope Power Systems, NE-34, is seeking an exemption from 10 CFR 71.19(d)(1), Previously Approved Package,[5] which states: '(d) NRC will approve modifications to the design and authorized contents of a Type B package, or a fissile material package, previously approved by NRC, provided--(1) The modifications of a Type B package are not significant with respect to the design, operating characteristics, or safe performance of the containment system, when the package is subjected to the tests specified in {section}71.71 and 71.73.' The LLNL staff had previously reviewed a request from Idaho National Laboratory (INL) to reconfigure national security PCVs to standard PCVs. With a nominal 50% reduction in both the height and the volume, the LLNL staff initially deemed the modifications to be significant, which would not be allowed under the provisions of 10 CFR 71.19(d)(1)--see above. As a follow-up, the DOE requested additional clarification from the Nuclear Regulatory Commission (NRC). The NRC concluded that the reconfiguration would be a new fabrication, and that an exemption to the regulations would be required to allow its use, as per the requirements specified in 10 CFR 71.19(c)(1), Previously Approved Package: '(c) A Type B(U) package, a Type B(M) package, or a fissile material package previously approved by the NRC with the designation '-85' in the identification number of the NRC CoC, may be used under the general license of {section}71.17 with the following additional conditions: (1) Fabrication of the package must be satisfactorily completed by December 31, 2006, as demonstrated by application of its model number in accordance with 71.85(c).' Although the preferred approach toward the resolution of this issue would be for the applicant to submit an updated SARP, the applicant has stated that the process of updating the Model Mound 1KW Package SARP is a work that is in progress, but that the updated SARP is not yet ready for submittal. The applicant has to provide a submittal, proving that the package meets the '-96' requirements of International Atomic Energy Agency (IAEA) Safety Standards Series No. TS-R-1, in order to fabricate approved packagings after December 31, 2006. The applicant has further stated that all other packaging features, as described in the currently approved Model Mound 1KW Package SARP, remain unchanged. This report documents the LLNL review of the waiver request. The specific review for each SARP Chapter is documented.

West, M; Hafner, R

2008-05-05

410

Ventilator associated pneumonia and infection control  

PubMed Central

Ventilator associated pneumonia (VAP) is the leading cause of morbidity and mortality in intensive care units. The incidence of VAP varies from 7% to 70% in different studies and the mortality rates are 20–75% according to the study population. Aspiration of colonized pathogenic microorganisms on the oropharynx and gastrointestinal tract is the main route for the development of VAP. On the other hand, the major risk factor for VAP is intubation and the duration of mechanical ventilation. Diagnosis remains difficult, and studies showed the importance of early initiation of appropriate antibiotic for prognosis. VAP causes extra length of stay in hospital and intensive care units and increases hospital cost. Consequently, infection control policies are more rational and will save money.

Alp, Emine; Voss, Andreas

2006-01-01

411

Air movement, comfort and ventilation in workstations  

SciTech Connect

This report presents findings from a research project to investigate the effects of office partition design on air movement, worker comfort, and ventilation in workstations. The objectives of the study were to evaluate the comfort and ventilation conditions produced by a conventional ceiling supply-and-return air distribution system in workstations separated by (1) solid partitions of different height (75 in. (1.9 m), 65 in. (1.65 m), 42 in. (1.1 m), and 0 in. (partitions removed)), and (2) prototype Steelcase airflow'' partitions, containing a gap positioned at the bottom of the partition. The project consisted primarily of experiments performed in a full-scale Controlled Environment Chamber (CEC) located in the Building Science Laboratory, Department of Architecture, University of California, Berkeley. 25 refs., 28 figs., 9 tabs.

Bauman, F.S.; Arens, E.A.; Johnston, L.P.; Zhang, H. (California Univ., Berkeley, CA (United States). Center for Environmental Design Research); Fisk, W.J.; McNeel, P.J.; Pih, D. (Lawrence Berkeley Lab., CA (United States))

1991-04-01

412

The techniques used to sedate ventilated patients  

Microsoft Academic Search

A survey of sedation techniques for ventilated patients was performed by visiting 34 Intensive Care Units in Great Britain and Northern Ireland. The opiates in frequent use were phenoperidine (21 units-62% of units), papaveretum (11–32%) and morphine (9–26%). Many units used more than one opiate. Levorphanol, buprenorphine, pethidine, fentanyl and codeine were little used. Frequent use of diazepam was found

H. M. Merriman; Princess MargaretHospital

1981-01-01

413

Improving the ventilation of short workings  

Microsoft Academic Search

Local-action ventilators (LAV) are universally used to circulate air in the faces of preliminary and productive workings in coal and ore raines. LAV are also used in small-bore workings within excavational sections of gas fields. In recent years, LAV have graduaUy been introduced in particular cases of dead-end blasting faces. Safety rules [1] require the use of LAV for chamber-type

V. K. Lukashchuk; A. M. Goryunov; A. N. Naumov; V. I. Klopov; G. I. Kulakov

1993-01-01

414

Time of non-invasive ventilation  

Microsoft Academic Search

Non-invasive ventilation (NIV) is a safe, versatile and effective technique that can avert side effects and complications\\u000a associated with endotracheal intubation. The success of NIV relies on several factors, including the type and severity of\\u000a acute respiratory failure, the underlying disease, the location of treatment, and the experience of the team. The time factor\\u000a is also important. NIV is primarily used

Stefano Nava; Paolo Navalesi; Giorgio Conti

2006-01-01

415

Hypnotic and Nonhypnotic Control of Ventilation  

Microsoft Academic Search

The present study examined the effects of: 1) breathing air versus breathing 5% CO2; 2) waking versus self-hypnotic conditions; and 3) neutral versus reduced respiratory rate instructions on four measures of ventilatory functioning (respiratory rate, tidal volume, expired minute ventilation, and end-tidal Pco2). Twelve high-hypnotizable normal volunteer subjects were studied in a repeated-measures, multivariate analysis of variance design. Significant main

Edgar L. Anderson Jr; Edward J. Frischholz; Mark J. Trentalange

1988-01-01

416

Ventilation during total intravenous anaesthesia with ketamine  

Microsoft Academic Search

Total intravenous anaesthesia with ketamine (TIVAK) is widely used throughout the world especially in precarious conditions.\\u000a Although ketamine is usually considered to provide good respiratory function and may be used with spontaneous ventilation,\\u000a recent studies have shown that desaturations may occur. Seventy-six adults and 64 children scheduled for peripheral surgery\\u000a were randomly allocated to breathe spontaneously room air or 40%

Luc-Marie Joly; Dan Benhamou

1994-01-01

417

Ventilator-associated pneumonia: caveats for benchmarking  

Microsoft Academic Search

ObjectiveTo determine the influence of using different denominators on risk estimates of ventilator-associated pneumonia (VAP).Design and settingProspective cohort study in the medical ICU of a large teaching hospital.PatientsAll consecutive patients admitted for more than 48 h between October 1995 and November 1997.Measurements and resultsWe recorded all ICU-acquired infections using modified CDC criteria. VAP rates were reported per 1,000 patient-days, patient-days at

Philippe Eggimann; Stéphane Hugonnet; Hugo Sax; Sylvie Touveneau; Jean-Claude Chevrolet; Didier Pittet

2003-01-01

418

Perception of draught in ventilated spaces  

Microsoft Academic Search

One hundred subjects were exposed to air velocities fluctuating in the same manner as in typically ventilated spaces. Each subject, dressed to obtain a neutral thermal sensation, participated in three experiments at an air temperature of 20, 23 and 26°C. In each experiment subjects were sedentary and exposed to six mean air velocities ranging from 0·05 to 0·40m\\/s. They were

P. O. FANGER; N. K. CHRISTENSEN

1986-01-01

419

Motorcycle helmet ventilation and heat transfer characteristics  

Microsoft Academic Search

1. Abstract Heat transfer characteristics of 10 motorcycle helmets were measured. Each helmet was tested three times on a manikin headform placed in a climate chamber (22 ºC and 50% RH) at the exit of a wind tunnel (50 ± 1.1 km·h-1). In every measurement a helmet was evaluated with the ventilation openings closed and open. Heat transfer ( Q&

C. P. Bogerd; P. A. Brühwiler

420

Limitations of jet ventilation through the laryngoscope  

Microsoft Academic Search

A series is presented of 100 patients who underwent direct laryngoscopy under general anaesthesia.\\u000a \\u000a Our preferred technique of ventilation is jet insufflation by an injector attached to the blade of the laryngoscope, as it\\u000a provides the surgeon with a quiet and completely exposed larynx. In nine cases, chest expansion was assessed as inadequate\\u000a by the anaesthetist. These patients were obese

I. Winerman; S. Ezra; A. Man; S. Segal

1982-01-01

421

[Researches on the mechanical ventilation trigger way].  

PubMed

A mechanical ventilation trigger way is set forth and a technical analysis on the pressure trigger way and flow trigger way is made in this paper. And it is pointed out that the PEEPi's influence on the human organism is the reason for the latter two kinds of trigger ways' notable differences in the measured values of the inspiration time and breath work. PMID:18581882

Li, Zhen-Hua

2008-03-01

422

Severe Legionella pneumonia successfully treated by independent lung ventilation with intrapulmonary percussive ventilation.  

PubMed

A case of severe Legionella pneumonia was successfully treated by independent lung ventilation (ILV) with intrapulmonary percussive ventilation (IPV). A 57-year-old man with lobar pneumonia was intubated and mechanically ventilated because of his deteriorating respiratory status. The diagnosis of Legionella pneumonia was made on the fourth day after admission and appropriate antibiotic therapy was commenced. On the fifth hospital day, ILV was commenced because the right unaffected lung was over-distended, his haemodynamic state was unstable and his left lung was producing copious amounts of purulent sputum. His right lung was ventilated and his left lung was treated with IPV owing to the existence of massive atelectasis. After treatment with antibiotics and ILV combined with IPV, his respiratory and haemodynamic status gradually improved. On the tenth day after admission, ILV was changed to conventional bilateral ventilation. The patient was extubated on the sixteenth hospital day and discharged from the intensive care unit 30 days after admission. The combination of ILV and IPV was therapeutically effective during the acute phase of unilateral severe Legionella pneumonia. PMID:18399877

Fujita, Motoki; Tsuruta, Ryosuke; Oda, Yasutaka; Kaneda, Kotaro; Miyauchi, Takashi; Kasaoka, Shunji; Maekawa, Tsuyoshi

2008-05-01

423

Effects of firn ventilation on isotopic exchange  

NASA Astrophysics Data System (ADS)

A new model of isotopic diffusion in the upper few meters of firn tracks the isotopic composition of both the ice matrix and the pore-space vapor through time in two dimensions. Stable isotopes in the vapor phase move through the firn by diffusion along concentration gradients and by advection. Wind-driven ventilation carries atmospheric water vapor into the firn, where it mixes with existing pore-space vapor. Unlike previous models, our model allows disequilibrium between pore-space vapor and the surrounding snow grains. We also calculate the isotopic effects of ventilation-driven sublimation and condensation in the firn. Model predictions of isotopic diffusion in firn compare favorably with existing diffusion models. Model results quantify what other investigators have suggested: isotopic change in the upper few meters is more rapid than can be explained by the Whillans and Grootes (1985) model; isotopic equilibration with atmospheric vapor is an important component of post-depositional isotopic change; and ventilation enhances isotopic exchange by creating regions of relatively rapid sublimation and condensation in the firn.

Neumann, A. Thomas; Waddington, D. Edwin

424

Why we ventilate our houses - An historical look  

SciTech Connect

The knowledge of how to ventilate buildings, and how much ventilation is necessary for human health and comfort, has evolved over centuries of trial and error. Humans and animals have developed successful solutions to the problems of regulating temperature and removing air pollutants through the use of ventilation. These solutions include ingenious construction methods, such as engineered passive ventilation (termite mounds and passive stacks), mechanical means (wing-powered, fans), and an evolving effort to identify problems and develop solutions. Ventilation can do more than help prevent building occupants from getting sick; it can provide an improved indoor environment. Codes and standards provide minimum legal requirements for ventilation, but the need for ventilation goes beyond code minima. In this paper we will look at indoor air pollutant sources over time, the evolution of ventilation strategies, current residential ventilation codes and standards (e.g., recently approved ASHRAE Standard 62.2), and briefly discuss ways in which we can go beyond the standards to optimize residential ventilation, reduce indoor air quality problems, and provide corresponding social and economic benefit.

Matson, Nance E.; Sherman, Max H.

2004-05-14

425

Uneven distribution of ventilation in acute respiratory distress syndrome  

PubMed Central

Introduction The aim of this study was to assess the volume of gas being poorly ventilated or non-ventilated within the lungs of patients treated with mechanical ventilation and suffering from acute respiratory distress syndrome (ARDS). Methods A prospective, descriptive study was performed of 25 sedated and paralysed ARDS patients, mechanically ventilated with a positive end-expiratory pressure (PEEP) of 5 cmH2O in a multidisciplinary intensive care unit of a tertiary university hospital. The volume of poorly ventilated or non-ventilated gas was assumed to correspond to a difference between the ventilated gas volume, determined as the end-expiratory lung volume by rebreathing of sulphur hexafluoride (EELVSF6), and the total gas volume, calculated from computed tomography images in the end-expiratory position (EELVCT). The methods used were validated by similar measurements in 20 healthy subjects in whom no poorly ventilated or non-ventilated gas is expected to be found. Results EELVSF6 was 66% of EELVCT, corresponding to a mean difference of 0.71 litre. EELVSF6 and EELVCT were significantly correlated (r2 = 0.72; P < 0.001). In the healthy subjects, the two methods yielded almost identical results. Conclusion About one-third of the total pulmonary gas volume seems poorly ventilated or non-ventilated in sedated and paralysed ARDS patients when mechanically ventilated with a PEEP of 5 cmH2O. Uneven distribution of ventilation due to airway closure and/or obstruction is likely to be involved.

Rylander, Christian; Tylen, Ulf; Rossi-Norrlund, Rauni; Herrmann, Peter; Quintel, Michael; Bake, Bjorn

2005-01-01

426

Glacial Ventilation of the North Pacific  

NASA Astrophysics Data System (ADS)

Previous work on sediment cores from the North Pacific showed that above ~2 km d13C on the benthic foram Cibicidoides was higher during glacial time than it is today, after correcting for secular change of ~0.3 permil. This led to the suggestion that the ocean was better ventilated either through greater transport of a paleo North Pacific Intermediate Water, or transport was the same as today and preformed d13C was higher ([O2] was higher). Below ~2km, d13C was about the same as today, after correction. A new synthesis of apparent ventilation ages based on the paired benthic (BF) and planktonic foram (PF) 14C method provides general support for the scenario based on d13C. Although many 14C data are available for this synthesis, we exercised some reasonable quality control by selecting data that met the following criteria: (1) analyses based on high deposition rate cores, or laminated intervals of cores, (2) analyses conducted at peaks in BF abundance, and (3) analyses from a narrow window of glacial maximum time (~18-20 ka). The result shows that above ~2.5 km apparent ventilation ages are less than today (better ventilation), and the one sample from >3km is the same as today (~1700 yrs). When d13C and BF-PF 14C data are compared between the North Atlantic and North Pacific Oceans, it seems likely the same water filled these basins deeper than ~3.5 km. d13C of each basin was about 0 permil, and although the average apparent ventilation age was ~1200 yrs for the North Atlantic during the LGM, the two oldest determinations are 1550 and 1450 yrs. The fly in the ointment is still the very low d13C observed in the South Atlantic sector of the Southern Ocean. Although the available data are reproducible and may not reflect low d13C in the fluff layer at the seafloor, results from a zonally averaged circulation-biogeochemistry model showed that d13C may become unlinked from nutrient content during a change of the ocean general circulation.

Keigwin, L. D.; Marchal, O.

2004-12-01

427

Comparison of actual tidal volume in neonatal lung model volume control ventilation using three ventilators.  

PubMed

In neonates, small changes in tidal volumes (V(T)) may lead to complications. Previous studies have shown a significant difference between ventilator-measured tidal volume and tidal volume delivered (actual V(T)). We evaluated the accuracy of three different ventilators to deliver small V(T) during volume-controlled ventilation. We tested Servo 300, 840 ventilator and Evita 4 Neoflow ventilators with lung models simulating normal and injured neonatal lung compliance models. Gas volume delivered from the ventilator into the test circuit (V(TV)) and actual V(T) to the test lung were measured using Ventrak respiration monitors at set V(T) (30 ml). The gas volume increase of the breathing circuit was then calculated. Tidal volumes of the SV300 and PB840 in both lung models were similar to the set V(T) and the actual tidal volumes in the injured model (20.7 ml and 19.8 ml, respectively) were significantly less than that in the normal model (27.4 ml and 23.4 ml). PB840 with circuit compliance compensation could not improve the actual V(T). V(TV) of the EV4N in the normal and the injured models (37.8 ml and 46.6 ml) were markedly increased compared with set V(T), and actual V(T) were similar to set V(T) in the normal and injured model (30.2 ml and 31.9 ml, respectively). EV4N measuring V(T) close to the lung could match actual V(T) to almost the same value as the set V(T) however the gas volume of the breathing circuit was increased. If an accurate value for the patient's actual V(T) is needed, this V(T) must be measured by a sensor located between the Y-piece and the tracheal tube. PMID:21823376

Toyama, H; Endo, Y; Ejima, Y; Matsubara, M; Kurosawa, S

2011-07-01

428

Urinary and dietary sodium and potassium associated with blood pressure control in treated hypertensive kidney transplant recipients: an observational study  

PubMed Central

Background In kidney transplant (Kt) recipients , hypertension is a major risk for cardiovascular complications but also for graft failure. Blood pressure (BP) control is therefore mandatory. Office BP (OBP) remains frequently used for clinical decisions, however home BP (HBP) have brought a significant improvement in the BP control. Sodium is a modifiable risk factor, many studies accounted for a decrease of BP with a sodium restricted diet. Increased potassium intake has been also recommended in hypertension management. Using an agreement between office and home BP, the present study investigated the relations between the BP control in Kt recipients and their urinary excretion and dietary consumption of sodium and potassium. Methods The BP control defined by OBP <140/90 mmHg and HBP <135/85 mmHg was tested in 70 Kt recipients (mean age 56?±?11.5 years; mean graft survival 7?±?6.6 years) treated with antihypertensive medications. OBP and HBP were measured with a validated oscillometric device (Omron M6®). The 24-hour urinary sodium (Na+) and potassium (K+) excretions as well as dietary intakes were compared between controlled and uncontrolled (in office and at home) recipients. Non parametric Wilcoxon Mann–Whitney Test was used for between groups comparisons and Fisher's exact test for frequencies comparisons. Pearson correlation coefficients and paired t-test were used when sample size was >30. Results Using an agreement between OBP and HBP, we identified controlled (21%) and uncontrolled recipients (49%). Major confounding effects susceptible to interfere with the BP regulation did not differ between groups, the amounts of sodium excretion were similar (154 ± 93 vs 162 ± 88 mmol/24 h) but uncontrolled patients excreted less potassium (68 ± 14 vs 54 ± 20 mmol/24 h; P?=?0.029) and had significantly lower potassium intakes (3279 ± 753 vs 2208 ± 720 mg/24 h; P?=?0.009), associated with a higher urinary Na+/K?+?ratio. Systolic HBP was inversely and significantly correlated to urinary potassium (r?=??0.48; P?=?0.002), a positive but non significant relation was observed with urinary sodium (r?=?0,30;P?=?0.074). Conclusions Half of the treated hypertensive Kt recipients remained uncontrolled in office and at home. Restoring a well-balanced sodium/potassium ratio intakes could be a non pharmacological opportunity to improve blood pressure control.

2012-01-01

429

Role of caveolin-1 expression in the pathogenesis of pulmonary edema in ventilator-induced lung injury  

PubMed Central

Caveolin-1 is a key regulator of pulmonary endothelial barrier function. Here, we tested the hypothesis that caveolin-1 expression is required for ventilator-induced lung injury (VILI). Caveolin-1 gene-disrupted (Cav-1-/-) and age-, sex-, and strain-matched wild-type (WT) control mice were ventilated using two protocols: volume-controlled with protective (8 mL/kg) versus injurious (21 mL/Kg) tidal volume for up to 6 hours; and pressure-controlled with protective (airway pressure = 12 cm H2O) versus injurious (30 cm H2O) ventilation to induce lung injury. Lung microvascular permeability (whole-lung 125I-albumin accumulation, lung capillary filtration coefficient [Kf, c]) and inflammatory markers (bronchoalveolar lavage [BAL] cytokine levels and neutrophil counts) were measured. We also evaluated histologic sections from lungs, and the time course of Src kinase activation and caveolin-1 phosphorylation. VILI induced a 1.7-fold increase in lung 125I-albumin accumulation, fourfold increase in Kf, c, significantly increased levels of cytokines CXCL1 and interleukin-6, and promoted BAL neutrophilia in WT mice. Lung injury by these criteria was significantly reduced in Cav-1-/- mice but fully restored by i.v. injection of liposome/Cav-1 cDNA complexes that rescued expression of Cav-1 in lung microvessels. As thrombin is known to play a significant role in mediating stretch-induced vascular injury, we observed in cultured mouse lung microvascular endothelial cells (MLECs) thrombin-induced albumin hyperpermeability and phosphorylation of p44/42 MAP kinase in WT but not in Cav-1-/- MLECs. Thus, caveolin-1 expression is required for mechanical stretch-induced lung inflammation and endothelial hyperpermeability in vitro and in vivo.

Maniatis, Nikolaos A.; Kardara, Matina; Hecimovich, Dan; Letsiou, Eleftheria; Castellon, Maricela; Roussos, Charalambos; Shinin, Vasily; Votta-Vellis, E. Gina; Schwartz, David E.; Minshall, Richard D.

2012-01-01

430

A pilot prospective study on closed loop controlled ventilation and oxygenation in ventilated children during the weaning phase  

PubMed Central

Introduction The present study is a pilot prospective safety evaluation of a new closed loop computerised protocol on ventilation and oxygenation in stable, spontaneously breathing children weighing more than 7 kg, during the weaning phase of mechanical ventilation. Methods Mechanically ventilated children ready to start the weaning process were ventilated for five periods of 60 minutes in the following order: pressure support ventilation, adaptive support ventilation (ASV), ASV plus a ventilation controller (ASV-CO2), ASV-CO2 plus an oxygenation controller (ASV-CO2-O2) and pressure support ventilation again. Based on breath-by-breath analysis, the percentage of time with normal ventilation as defined by a respiratory rate between 10 and 40 breaths/minute, tidal volume > 5 ml/kg predicted body weight and end-tidal CO2 between 25 and 55 mmHg was determined. The number of manipulations and changes on the ventilator were also recorded. Results Fifteen children, median aged 45 months, were investigated. No adverse event and no premature protocol termination were reported. ASV-CO2 and ASV-CO2-O2 kept the patients within normal ventilation for, respectively, 94% (91 to 96%) and 94% (87 to 96%) of the time. The tidal volume, respiratory rate, peak inspiratory airway pressure and minute ventilation were equivalent for all modalities, although there were more automatic setting changes in ASV-CO2 and ASV-CO2-O2. Positive end-expiratory pressure modifications by ASV-CO2-O2 require further investigation. Conclusion Over the short study period and in this specific population, ASV-CO2 and ASV-CO2-O2 were safe and kept the patient under normal ventilation most of the time. Further research is needed, especially for positive end-expiratory pressure modifications by ASV-CO2-O2. Trial registration ClinicalTrials.gov: NCT01095406

2012-01-01

431

Brain injury in chronically ventilated preterm neonates: collateral damage related to ventilation strategy.  

PubMed

Brain injury is a frequent comorbidity in chronically ventilated preterm infants. However, the molecular basis of the brain injury remains incompletely understood. This article discusses the subtle (diffuse) form of brain injury that has white matter and gray matter lesions without germinal matrix hemorrhage-intraventricular hemorrhage, posthemorrhagic hydrocephalus, or cystic periventricular leukomalacia. This article synthesizes data that suggest that diffuse lesions to white matter and gray matter are collateral damage related to ventilator strategy. Evidence is introduced from the 2 large-animal, physiologic models of evolving neonatal chronic lung disease that suggest that an epigenetic mechanism may underlie the collateral damage. PMID:22954278

Albertine, Kurt H

2012-09-01

432

Effects of passive limb movement on pulmonary ventilation.  

PubMed Central

This study was undertaken to determine if the observed increase in ventilation during passive limb movement was a reflex hyperventilation or a response to an increased metabolic need for oxygen. Experiments on human volunteers were designed to test the hypothesis that the rapid increase of ventilation at the onset of exercise was due to stimulation of the joints. Results of these studies showed significant increases in ventilation, oxygen consumption, carbon dioxide production, ventilation/oxygen consumption ratio, and heart rate compared to rest and recovery values. The data lead to the conclusion that the rapid increase of ventilation at the onset of exercise is a true hyperventilation and that stimulation of the joints can be a significant contributor to increased pulmonary ventilation.

Waisbren, S. J.; Whiting, C. S.; Nadel, E. R.

1990-01-01

433

Ethical challenges in home mechanical ventilation: A secondary analysis  

PubMed Central

The aim of this study was to explore the ethical challenges in home mechanical ventilation based on a secondary analysis of qualitative empirical data. The data included perceptions of healthcare professionals in hospitals and community health services and family members of children and adults using home mechanical ventilation. The findings show that a number of ethical challenges, or dilemmas, arise at all levels in the course of treatment: deciding who should be offered home mechanical ventilation, respect for patient and family wishes, quality of life, dignity and equal access to home mechanical ventilation. Other challenges were the impacts home mechanical ventilation had on the patient, the family, the healthcare services and the allocation of resources. A better and broader understanding of these issues is crucial in order to improve the quality of care for both patient and family and assist healthcare professionals involved in home mechanical ventilation to make decisions for the good of the patient and his or her family.

Dybwik, Knut; Nielsen, Erik Waage; Brinchmann, Berit St?re

2012-01-01

434

Skin breakdown in children and high-frequency oscillatory ventilation  

Microsoft Academic Search

Objective: To investigate the relationship of high-frequency oscillatory ventilation (HFOV) to skin breakdown on the scalp and ears in mechanically ventilated children.Study Design: Retrospective cohort study of 32 patients supported with HFOV paired with 32 patients supported with conventional mechanical ventilation (CV) in a pediatric intensive care unit (PICU).Results: By univariate analysis, more HFOV patients had skin breakdown than did

Jeffrey E. Schmidt; Richard J. Berens; Mary B. Zollo; Margaret Weisner; Carl G. M. Weigle

1998-01-01

435

CO/sub 2/-controlled ventilation system: pilot study  

SciTech Connect

Large savings in the cost of construction and operation could be made if ventilation were adapted to the prevailing need. Ventilation of empty rooms is a frequent extravagance. Amongst the most promising of present possibilities for indicating occupancy, and thus the ventilation need, is that of measuring the level of carbon dioxide. The project includes a test with equipment for CO2-control of the outdoor air-flow in an office building.

Soedergren, D.; Punttila, A.

1983-01-01

436

Current status of mechanical ventilation decision support systems: a review  

Microsoft Academic Search

Objectives of computerized decision support systems for mechanical ventilation are discussed. Questions considered are: Why\\u000a is computerized decision support for mechanical ventilation important? What parameter(s) should be optimized? What are the\\u000a differences between a single attribute and a multiattribute value function used for optimization? How is it possible to achieve\\u000a optimization in clinical practice with existing ventilators? How does one

Robert Rudowski; Thomas D. East; Reed M. Gardner

1996-01-01

437

Palliative noninvasive ventilation in patients with acute respiratory failure  

Microsoft Academic Search

Over the last two decades, the increasing use of noninvasive ventilation (NIV) has diminished the need for endotracheal ventilation,\\u000a thus decreasing the rate of ventilation-induced complications. Thus, NIV has decreased both intubation rates and mortality\\u000a rates in specific subsets of patients with acute respiratory failure (e.g., patients with hypercapnia, cardiogenic pulmonary\\u000a edema, immune deficiencies, or post-transplantation acute respiratory failure). NIV

Élie Azoulay; Alexandre Demoule; Samir Jaber; Achille Kouatchet; Anne-Pascale Meert; Laurent Papazian; Laurent Brochard

438

Noninvasive Positive-Pressure Ventilation in Patients With Malignancy  

Microsoft Academic Search

Noninvasive positive-pressure ventilation (NIPPV) is now accepted as the treatment of choice for subgroups of patients with acute respiratory failure. Noninvasive positive-pressure ventilation has traditionally not been considered in the management strategy of patients with malignancy; however, this mode of ventilatory support may be appropriate in some specific situations. Noninvasive positive-pressure ventilation is the preferred initial mode of ventilatory support

Paul E. Marik

2007-01-01

439

Single-shell tank ventilation upgrades needs analysis report  

SciTech Connect

This report was written to comply with the objectives of the Hanford Federal Facility Agreement and Consent Order, Tri-Party Agreement Milestone M-43-03 Provide to the Washington State Department of Ecology and Department of Health the Results of the Single-Shell Tank Ventilation Upgrades Needs Analysis. The needs analysis consists of identifying the current type and status of each single-shell tank ventilation system, identifying current and projected authorization basis requirements, and identifying ventilation system compliance deficiencies.

Kriskovich, J.R., Fluor Daniel Hanford

1997-02-03

440

Does a colour-coded blood pressure diary improve blood pressure control for patients in general practice: The CoCo trial  

PubMed Central

Background Insufficient blood pressure control is a frequent problem despite the existence of effective treatment. Insufficient adherence to self-monitoring as well as to therapy is a common reason. Blood pressure self-measurement at home (Home Blood Pressure Measurement, HBPM) has positive effects on treatment adherence and is helpful in achieving the target blood pressure. Only a few studies have investigated whether adherence to HBPM can be improved through simple measures resulting also in better blood pressure control. Objective Improvement of self-monitoring and improved blood pressure control by using a new colour-coded blood pressure diary. Outcome Primary outcome: Change in systolic and/or diastolic blood pressure 6 months after using the new colour-coded blood pressure diary. Secondary outcome: Adherence to blood pressure self-measurement (number of measurements/entries). Methods/Design Randomised controlled study. Population: 138 adult patients in primary care with uncontrolled hypertension despite therapy. The control group uses a conventional blood pressure diary; the intervention group uses the new colour-coded blood pressure diary (green, yellow, red according a traffic light system). Expected results/conclusion The visual separation and entries in three colour-coded areas reflecting risk (green: blood pressure in the target range ? 140/? 90 mmHg, yellow: blood pressure >140/>90 mmHg, red: blood pressure in danger zone > 180 mmHg/>110 mmHg) lead to better self-monitoring compared with the conventional (non-colour-coded) blood pressure booklet. The colour-coded, visualised information supports improved perception (awareness and interpretation) of blood pressure and triggers correct behaviour, in the means of improved adherence to the recommended treatment as well as better communication between patients and doctors resulting in improved blood pressure control. Trial registration ClinicalTrials.gov ID NCT01013467

2010-01-01

441

Blood pressure control in women is improved following cognitive behavioral intervention ( CBI ) and with the use of home blood pressure monitoring  

Microsoft Academic Search

We studied the immediate and sustained effects of cognitive-behavioral intervention(CBI) on blood pressure control. The CBI is a 30 day home based self-learning program involving reading tailored messages designed build knowledge (cognitive representations) to improve medication taking behavior and enhance patients sense of control.We hypothesized that those receiving CBI and home blood pressure monitoring (HBP) (n=64),vs HBP alone (n=62), would

Susan P. Steigerwalt; Gail Makos; Tracy Saunders; Margaret Scisney-Matlock

2003-01-01

442

Radionuclide Releases During Normal Operations for Ventilated Tanks  

SciTech Connect

This calculation estimates the design emissions of radionuclides from Ventilated Tanks used by various facilities. The calculation includes emissions due to processing and storage of radionuclide material.

Blunt, B.

2001-09-24

443

Effects of mechanical ventilation on diaphragm function and biology  

Microsoft Academic Search

ABSTRACT: The pathophysiological mechanisms,of weaning,from,mechanical ventilation are not fully known, but there is accumulating evidence that mechanical ventilation induces inspiratory muscle dysfunction. Recently, several animal models have provided potential mechanisms for mecha- nical ventilation-induced effects on muscle function. In patients, weaning difficulties are associated with inspiratory muscle,weakness,and,reduced,endurance,capacity. Animal,studies demonstrated,that diaphragm,force was,already,decreased,after 12 h of controlled mechanical,ventilation and this worsened,with time

G. Gayan-Ramirez; M. Decramer

2002-01-01

444

Natural Ventilation for the Prevention of Airborne Contagion  

PubMed Central

Background Institutional transmission of airborne infections such as tuberculosis (TB) is an important public health problem, especially in resource-limited settings where protective measures such as negative-pressure isolation rooms are difficult to implement. Natural ventilation may offer a low-cost alternative. Our objective was to investigate the rates, determinants, and effects of natural ventilation in health care settings. Methods and Findings The study was carried out in eight hospitals in Lima, Peru; five were hospitals of “old-fashioned” design built pre-1950, and three of “modern” design, built 1970–1990. In these hospitals 70 naturally ventilated clinical rooms where infectious patients are likely to be encountered were studied. These included respiratory isolation rooms, TB wards, respiratory wards, general medical wards, outpatient consulting rooms, waiting rooms, and emergency departments. These rooms were compared with 12 mechanically ventilated negative-pressure respiratory isolation rooms built post-2000. Ventilation was measured using a carbon dioxide tracer gas technique in 368 experiments. Architectural and environmental variables were measured. For each experiment, infection risk was estimated for TB exposure using the Wells-Riley model of airborne infection. We found that opening windows and doors provided median ventilation of 28 air changes/hour (ACH), more than double that of mechanically ventilated negative-pressure rooms ventilated at the 12 ACH recommended for high-risk areas, and 18 times that with windows and doors closed (p < 0.001). Facilities built more than 50 years ago, characterised by large windows and high ceilings, had greater ventilation than modern naturally ventilated rooms (40 versus 17 ACH; p < 0.001). Even within the lowest quartile of wind speeds, natural ventilation exceeded mechanical (p < 0.001). The Wells-Riley airborne infection model predicted that in mechanically ventilated rooms 39% of susceptible individuals would become infected following 24 h of exposure to untreated TB patients of infectiousness characterised in a well-documented outbreak. This infection rate compared with 33% in modern and 11% in pre-1950 naturally ventilated facilities with windows and doors open. Conclusions Opening windows and doors maximises natural ventilation so that the risk of airborne contagion is much lower than with costly, maintenance-requiring mechanical ventilation systems. Old-fashioned clinical areas with high ceilings and large windows provide greatest protection. Natural ventilation costs little and is maintenance free, and is particularly suited to limited-resource settings and tropical climates, where the burden of TB and institutional TB transmission is highest. In settings where respiratory isolation is difficult and climate permits, windows and doors should be opened to reduce the risk of airborne contagion.

Escombe, A. Roderick; Oeser, Clarissa C; Gilman, Robert H; Navincopa, Marcos; Ticona, Eduardo; Pan, William; Martinez, Carlos; Chacaltana, Jesus; Rodriguez, Richard; Moore, David A. J; Friedland, Jon S; Evans, Carlton A

2007-01-01

445

High frequency oscillatory ventilation versus synchronized intermittent mandatory ventilation in preterm neonates with hyaline membrane disease: a randomized controlled trial.  

PubMed

This randomized controlled study was conducted to compare the efficacy and safety of High frequency oscillatory ventilation (HFOV) and Synchronized intermittent mandatory ventilation (SIMV) in preterm neonates with hyaline membrane disease requiring ventilation. The ventilation strategy in both the groups included achieving optimal lung recruitment and targeted blood gases. 49 patients received HFOV and 61 SIMV. The baseline characteristics were similar in both the groups. HFOV group demonstrated better early oxygenation, enabled reduction in oxygenation index (OI) within 24 h of ventilation (difference in mean OI at 1, 6, and 24 h of ventilation: P=0.004 in HFOV, and 0.271 in SIMV group). Duration of hospital stay was shorter in HFOV group (P=0.003). The complication rate and survival were similar in two groups. PMID:22700666

Singh, S N; Malik, G K; Prashanth, G P; Singh, Anita; Kumar, Mala

2012-05-01

446

Ventilator-associated pneumonia: a review.  

PubMed

Ventilator-associated pneumonia (VAP) is the most common infection seen in intensive care units (ICUs); it accounts for one-fourth of the infections occurring in critically ill patients and is the reason for half of antibiotic prescriptions in mechanically ventilated patients. In addition to being a financial burden on ICUs, it continues to contribute significantly to the morbidity and mortality of ICU patients, with an estimated attributable mortality rate of 8% to 15%. While the pathophysiology of VAP remains relatively unchanged, diagnostic techniques and preventive measures are constantly evolving. The focus of this article is on recent trends in VAP epidemiology, modifiable risk factors, diagnostic techniques, challenges in management, and current data on the prevention of VAP. Important messages that the reader should take away include: 1) There is no gold standard for the diagnosis of VAP; whenever VAP is suspected, if feasible, a quantitative culture should be obtained by invasive or noninvasive methods (whichever is more readily available before initiation of antibiotics); 2) Suspicion based on clinical features should prompt the initiation of a broad spectrum of antibiotics depending on suspected pathogens; 3) Close attention should be paid to de-escalation of antibiotics once microbiological results become available or as the patient starts responding clinically; the ideal duration of treatment should be 8 days instead of the conventional 10 to 14 days, except in situations where Pseudomonas may be suspected or the patient's comorbidities dictate otherwise; and 4) Prevention remains the key to reducing the burden of VAP. We promote the proven preventive measures of using noninvasive ventilation when possible, semirecumbent patient positioning, continuous aspiration of subglottic secretions, and oral chlorhexidine washes along with stress ulcer prophylaxis only after careful assessment of the risks versus benefits. PMID:22406885

Ashraf, Madiha; Ostrosky-Zeichner, Luis

2012-02-01

447

Synchronous intermittent mandatory ventilation modes compared with patient triggered ventilation during weaning.  

PubMed Central

The efficacy of combining rate and pressure reduction during weaning by synchronous intermittent mandatory ventilation (SIMV) were compared with weaning by patient triggered ventilation (PTV) (pressure reduction alone) in two randomised trials. Regardless of ventilation mode, pressure was reduced to the same level according to the size of the infant. In the first trial, the SIMV rate was also reduced progressively to a minimum of 20 breaths/minute, and in the second to five breaths/minute. Forty premature infants aged 15 days of age or less were randomly allocated into each trial. No significant differences were f