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Sample records for hypotension marked diuresis

  1. Nociceptin/orphanin FQ (N/OFQ)-evoked bradycardia, hypotension, and diuresis are absent in N/OFQ peptide (NOP) receptor knockout mice.

    PubMed

    Burmeister, Melissa A; Ansonoff, Michael A; Pintar, John E; Kapusta, Daniel R

    2008-09-01

    Intracerebroventricular administration of the opioid-like peptide nociceptin/orphanin FQ (N/OFQ) produces bradycardia, hypotension, and diuresis in mice. We hypothesized that these responses are solely caused by selective activation of central N/OFQ peptide (NOP) receptors. To test this premise, we first examined whether i.c.v. N/OFQ produced dose-dependent diuretic and cardiovascular depressor responses in commercially available C57BL/6 mice. Next, using doses established in these studies, we examined the renal excretory and cardiovascular responses to i.c.v. N/OFQ in conscious transgenic NOP receptor knockout mice (NOP(-/-)). In metabolic studies, i.c.v. N/OFQ, but not saline vehicle, dose-dependently increased urine output (V) in NOP(+/+); this response was significant at 3 nmol (N/OFQ, V = 0.39 +/- 0.10 ml/2 h; saline, 0.08 +/- 0.05 ml/2 h). The N/OFQ-evoked diuresis was absent in littermate NOP(-/-) (N/OFQ, V = 0.06 +/- 0.06 ml/2 h; saline, 0.03 +/- 0.03 ml/2 h). There were no significant changes in urinary sodium or potassium excretion or free water clearance in either group. In telemetry studies, i.c.v. N/OFQ dose dependently lowered heart rate (HR) and mean arterial pressure (MAP). At 3 nmol N/OFQ, both HR and MAP were reduced in NOP(+/+) (peak DeltaHR = -217 +/- 31 bpm; peak DeltaMAP =-47 +/- 7 mm Hg) compared with saline (peak DeltaHR =-14 +/- 5 bpm; peak DeltaMAP = 2 +/- 3 mm Hg). These N/OFQ-evoked bradycardic and hypotensive responses were absent in NOP(-/-) (peak DeltaHR =-13 +/- 17 bpm; peak DeltaMAP =-2 +/- 4 mm Hg, respectively). Basal 24-h cardiovascular and renal excretory function were not different between NOP(-/-) and NOP(+/+) mice. These results establish that the bradycardia, hypotension and diuresis produced by centrally administered N/OFQ are mediated by selective activation of NOP receptors.

  2. Osmotic diuresis

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/001266.htm Osmotic diuresis To use the sharing features on this page, please enable JavaScript. Osmotic diuresis is increased urination due to the presence of ...

  3. Spontaneous intracranial hypotension manifesting as a unilateral subdural hematoma with a marked midline shift.

    PubMed

    Inamasu, Joji; Moriya, Shigeta; Shibata, Junpei; Kumai, Tadashi; Hirose, Yuichi

    2015-01-01

    Spontaneous intracranial hypotension (SIH) is a syndrome in which hypovolemia of the cerebrospinal fluid (CSF) results in various symptoms. Although its prognosis is usually benign, cases with a rapid neurologic deterioration resulting in an altered mental status have been reported. One of the characteristic radiographic findings in such cases is the presence of bilateral accumulation of subdural fluid (hematoma/hygroma). When SIH-related subdural hematoma is present only unilaterally with a concomitant midline shift, making an accurate diagnosis may be challenging, and inadvertent hematoma evacuation may result in further neurologic deterioration. We report a 58-year-old woman with an altered mental status who had visited a local hospital and in whom a brain CT showed a unilateral subdural hematoma with a marked midline shift. She was referred to our department because of her neurologic deterioration after hematoma evacuation. A CT myelography revealed a massive CSF leakage in the entire thoracic epidural space. She made a full neurologic recovery following blood patch therapy. Our case is unique and educational because the suspicion for SIH as an underlying cause of subdural hematoma is warranted in nongeriatric patients not only with bilateral but also unilateral lesions. An immediate search for CSF leakage may be important in cases with failed hematoma evacuation surgery.

  4. Postobstructive diuresis

    PubMed Central

    Halbgewachs, Colin; Domes, Trustin

    2015-01-01

    Abstract Objective To educate primary health care professionals about the diagnosis and treatment of postobstructive diuresis (POD), a rare but potentially lethal complication associated with the relief of urinary obstructions. Sources of information The main concepts and clinical evidence reviewed in this article were derived from a literature search of PubMed and Google Scholar. Expert opinion was used to supplement recommendations in areas with little evidence. Main message Urinary retention is a frequently encountered presentation seen by all physicians. Most family physicians are comfortable treating these patients, initiating investigations, and organizing appropriate follow-up. This article reviews a rare but potentially lethal complication known as POD. Postobstructive diuresis is a polyuric response initiated by the kidneys after the relief of a substantial bladder outlet obstruction. In severe cases this condition can become pathologic, resulting in dehydration, electrolyte imbalances, and death if not adequately treated. Primary care physicians should be familiar with this potential clinical entity, especially as they are generally the first to encounter and treat these patients. Conclusion Physicians aware of POD will be able to identify patients at risk and arrange the appropriate monitoring after relieving a urinary obstruction. Early diagnosis and treatment of pathologic POD will prevent mortality. PMID:25821871

  5. Orthostatic Hypotension (Postural Hypotension)

    MedlinePlus

    ... This condition is more common in older adults. Risk factors The risk factors for orthostatic hypotension include: Age. Orthostatic hypotension is ... a result of orthostatic hypotension can be a risk factor for stroke due to the reduced blood supply ...

  6. Orthostatic Hypotension (Postural Hypotension)

    MedlinePlus

    ... happens, you may be asked to wear a 24-hour Holter monitor to record your heart's electrical activity ... medications for people who aren't helped with lifestyle changes or other medications. There are many simple steps to managing or preventing orthostatic hypotension. Your doctor may give ...

  7. A case of marked diuresis by combined dopamine and atrial natriuretic peptide administration without renal injury in acute decompensated heart failure.

    PubMed

    Kamiya, Masataka; Sato, Naoki; Akiya, Mai; Okazaki, Hirotake; Takahashi, Yasuhiro; Mizuno, Kyoichi

    2013-01-01

    Renal injury is an important factor for worsening outcome in acute decompensated heart failure (ADHF). An 81-year-old woman was admitted due to ADHF with dyspnea and mild peripheral edema. The patient was managed with intravenous administration of atrial natriuretic peptide (ANP) at a dose of 0.0125 μg/kg/minute, which did not control volume overload even at an increased dose of 0.025 μg/kg/minute. After a low dose of dopamine (DA) of 1.0 μg/kg/ minute was added, urine output increased markedly to 120 from 30 mL/hour. Furthermore, her heart rate decreased to 80-100 from 120 bpm and the congestion improved with a reduced brain natriuretic peptide level. Interestingly, the combination of ANP and DA therapy reduced serum creatinine as well as the levels of urinary liver-type fatty acid binding protein, a novel reno-tubular stress marker, by 98.9%, and an oxidative stress marker, urinary 8-hydroxydeoxyguanosine, by 88.2% from baseline levels. Thus, this ADHF patient, a nonresponder to ANP alone, improved without renal injury when administered combination therapy consisting of low doses of ANP and DA, suggesting that this combined therapy might be useful for better management of ADHF in patients without diuretic responses with ANP alone. Further prospective studies are warranted.

  8. Orthostatic hypotension

    NASA Technical Reports Server (NTRS)

    Grimm, J. J.

    1980-01-01

    Following a brief physiopathological review, orthostatic hypotension is classified into three groups: organic, functional and medication-dependent. The importance of etiological diagnosis, the use of objective tests and appropriate therapy, especially concerning the organic forms, is stressed.

  9. Mark.

    ERIC Educational Resources Information Center

    Lipman, Matthew; Smith, Theresa L., Ed.

    Mark is the central character in this story designed to help adolescents formulate a philosophy of values. The story is well suited for use in high school social studies courses and/or in philosophy or guidance units. Mark's thoughts and actions are reported as he interacts with his family, friends, acquaintances, and individuals of authority…

  10. Surfactant therapy and spontaneous diuresis.

    PubMed

    Bhat, R; John, E; Diaz-Blanco, J; Ortega, R; Fornell, L; Vidyasagar, D

    1989-03-01

    The effect of artificial surfactant therapy on renal function and the onset of spontaneous diuresis was prospectively evaluated in 19 infants with hyaline membrane disease in a double-blind, controlled study. Twelve infants were in the surfactant group; seven infants received placebo (0.9% saline solution). There was no difference in the time of onset of spontaneous diuresis (as defined by output greater than or equal to 80% of intake). The glomerular filtration rate, determined by endogenous creatinine clearance, was also similar in the surfactant- and placebo-treated infants during the first 3 days of life. The fractional excretion of sodium was significantly higher in the placebo group at 24 hours and 36 hours. Infants in the placebo group had a higher negative sodium balance than those in the surfactant group. Ventilatory status improved significantly soon after surfactant treatment, as evidenced by improvement in the alveolar/arterial oxygen pressure ratio and by a lower mean airway pressure. These data suggest that ventilatory status can be improved without diuresis; the factors that regulate diuresis are multiple and not fully understood.

  11. Orthostatic hypotension

    NASA Technical Reports Server (NTRS)

    Ninet, J.

    1981-01-01

    Basic orientation of the article, by the leader of a group of medical researchers associated with hospitals in Lyon, France, is toward definition and classification. A table divides OH (orthostatic hypotension) according to physiopathological classification into sympathicotonic and asympathicotonic types and then each of these into primary and secondary with subdivisions. The figure sketches organization and functioning of the baroreflex arc. Applications to clinical study of circulatory reflexes, listing measurement tests and the biological study of hormonal regulation listing the appropriate kinds of studies. Data are not given.

  12. Diuresis and voiding pattern in healthy schoolchildren.

    PubMed

    Mattsson, S; Lindström, S

    1995-12-01

    To analyse how differences in diuresis affect the normal pattern of micturition of healthy children. Two hundred and six healthy continent schoolchildren, aged 7-15 years, completed a frequency/volume chart for 24 h by recording the time and volume of each micturition. Several diuresis variables were calculated from these charts and compared with sex, age, oral fluid intake, functional bladder capacity, voiding intervals and volumes. The weight-corrected mean diuresis per 24 h varied 10-fold between individuals, independently of recorded fluid intake. In the majority, the diuresis decreased during the night, but the opposite diurnal pattern occurred in 12% of the children. The individual night-time diuresis was positively correlated with functional bladder capacity and the daytime diuresis was positively correlated with voiding frequency. The weight-corrected diuresis varies many-fold among healthy continent children. A substantial proportion has a reversed diurnal pattern with a larger diuresis during the night. The individual bladder size is adapted to accommodate their typical nightly urine production.

  13. Types of Hypotension

    MedlinePlus

    ... Children often outgrow NMH. Severe Hypotension Linked to Shock Shock is a life-threatening condition in which blood ... work well. Blood pressure drops much lower in shock than in other types of hypotension. Many factors ...

  14. Sporadic hypokalemic paralysis caused by osmotic diuresis in diabetes mellitus.

    PubMed

    Vishnu, Venugopalan Y; Kattadimmal, Anoop; Rao, Suparna A; Kadhiravan, Tamilarasu

    2014-07-01

    A wide variety of neurological manifestations are known in patients with diabetes mellitus. We describe a 40-year-old man who presented with hypokalemic paralysis. On evaluation, we found that the cause of the hypokalemia was osmotic diuresis induced by marked hyperglycemia due to undiagnosed diabetes mellitus. The patient had an uneventful recovery with potassium replacement, followed by glycemic control with insulin. Barring a few instances of symptomatic hypokalemia in the setting of diabetic emergencies, to our knowledge uncomplicated hyperglycemia has not been reported to result in hypokalemic paralysis.

  15. [Hypotension from endocrine origin].

    PubMed

    Vantyghem, Marie-Christine; Douillard, Claire; Balavoine, Anne-Sophie

    2012-11-01

    Hypotension is defined by a low blood pressure either permanently or only in upright posture (orthostatic hypotension). In contrast to hypertension, there is no threshold defining hypotension. The occurrence of symptoms for systolic and diastolic measurements respectively below 90 and 60 mm Hg establishes the diagnosis. Every acute hypotensive event should suggest shock, adrenal failure or an iatrogenic cause. Chronic hypotension from endocrine origin may be linked to adrenal failure from adrenal or central origin, isolated hypoaldosteronism, pseudohypoaldosteronism, pheochromocytoma, neuro-endocrine tumors (carcinoïd syndrome) or diabetic dysautonomia. Hypotension related to hypoaldosteronism associates low blood sodium and above all high blood potassium levels. They are generally classified according to their primary (hyperreninism) or secondary (hyporeninism) adrenal origin. Isolated primary hypoaldosteronisms are rare in adults (intensive care unit, selective injury of the glomerulosa area) and in children (aldosterone synthase deficiency). Isolated secondary hypoaldosteronism is related to mellitus diabetes complicated with dysautonomia, kidney failure, age, iatrogenic factors, and HIV infections. In both cases, they can be associated to glucocorticoid insufficiency from primary adrenal origin (adrenal failure of various origins with hyperreninism, among which congenital 21 hydroxylase deficiency with salt loss) or from central origin (hypopituitarism with hypo-reninism). Pseudohypoaldosteronisms are linked to congenital (type 1 pseudohypoaldosteronism) or acquired states of resistance to aldosterone. Acquired salt losses from enteric (total colectomy with ileostomy) or renal (interstitial nephropathy, Bartter and Gitelman syndromes…) origin might be responsible for hypotension and are associated with hyperreninism-hyperaldosteronism. Hypotension is a rare manifestation of pheochromocytomas, especially during surgical removal when the patient has not been

  16. Immersion diuresis without expected suppression of vasopressin

    NASA Technical Reports Server (NTRS)

    Keil, L. C.; Silver, J. E.; Wong, N.; Spaul, W. A.; Greenleaf, J. E.; Kravik, S. E.

    1984-01-01

    There is a shift of blood from the lower parts of the body to the thoracic circulation during bed rest, water immersion, and presumably during weightlessness. On earth, this central fluid shift is associated with a profound diuresis. However, the mechanism involved is not yet well understood. The present investigation is concerned with measurements regarding the plasma vasopressin, fluid, electrolyte, and plasma renin activity (PRA) responses in subjects with normal preimmersion plasma vasopressin (PVP) concentration. In the conducted experiments, PRA was suppressed significantly at 30 min of immersion and had declined by 74 percent by the end of the experiment. On the basis of previously obtained results, it appears that sodium excretion during immersion may be independent of aldosterone action. Experimental results indicate that PVP is not suppressed by water immersion in normally hydrated subjects and that other factors may be responsible for the diuresis.

  17. What Is Hypotension?

    MedlinePlus

    ... abnormally low blood pressure. Blood pressure is the force of blood pushing against the walls of the ... are flowing to your brain, kidneys, and other vital organs. Most forms of hypotension happen because your ...

  18. What Causes Hypotension?

    MedlinePlus

    ... your risk of orthostatic hypotension. These medicines include: Diuretics, also called "water pills" Calcium channel blockers Angiotensin- ... insulin) Severe diarrhea Severe kidney disease Overuse of diuretics A major decrease in the heart's ability to ...

  19. Living with Hypotension

    MedlinePlus

    ... Clinical Trials Links Related Topics Anemia Arrhythmia Cardiogenic Shock Heart Attack Heart Valve Disease Send a link ... about your blood pressure. Severe hypotension linked to shock is an emergency. Shock can lead to death ...

  20. Effects of vasopressin administration on diuresis of water immersion in normal humans

    NASA Technical Reports Server (NTRS)

    Epstein, M.; Denunzio, A. G.; Loutzenhiser, R. D.

    1981-01-01

    The influence of vasopressin suppression on the diuresis encountered during water immersion is investigated in studies on normal humans immersed to the neck. Six hydrated male subjects were studied on two occasions while undergoing 6 h of immersion without or during the administration of aqueous vasopressin for the initial 4 h. Neck immersion is found to result in a significant increase in urinary flow rate beginning in the first hour and persisting throughout the immersion. The administration of vasopressin markedly attenuated the diuretic response throughout the period of infusion, while cessation of vasopressin administration during the final 2 h of immersion resulted in a marked offset of the antidiuresis. Results thus support the view that the suppression of antidiuretic hormone contributes to the immersion diuresis of hydrated subjects.

  1. Effects of vasopressin administration on diuresis of water immersion in normal humans

    NASA Technical Reports Server (NTRS)

    Epstein, M.; Denunzio, A. G.; Loutzenhiser, R. D.

    1981-01-01

    The influence of vasopressin suppression on the diuresis encountered during water immersion is investigated in studies on normal humans immersed to the neck. Six hydrated male subjects were studied on two occasions while undergoing 6 h of immersion without or during the administration of aqueous vasopressin for the initial 4 h. Neck immersion is found to result in a significant increase in urinary flow rate beginning in the first hour and persisting throughout the immersion. The administration of vasopressin markedly attenuated the diuretic response throughout the period of infusion, while cessation of vasopressin administration during the final 2 h of immersion resulted in a marked offset of the antidiuresis. Results thus support the view that the suppression of antidiuretic hormone contributes to the immersion diuresis of hydrated subjects.

  2. Spontaneous intracranial hypotension.

    PubMed Central

    Renowden, S A; Gregory, R; Hyman, N; Hilton-Jones, D

    1995-01-01

    The clinical features and radiological appearances of spontaneous intracranial hypotension are described in three patients and the medical literature is reviewed. Awareness of this condition and its differentiation from more sinister meningitic processes is important to avoid unnecessary invasive investigations and to allow prompt diagnosis and effective treatment. Images PMID:8530936

  3. Norepinephrine-induced diuresis in chronically ethanol-treated rats

    SciTech Connect

    Pohorecky, L.A. )

    1989-01-01

    Previous research from this laboratory indicated that noradrenergic mechanisms might mediate ethanol diuresis. Experiments described here examined changes in sensitivity of noradrenergic mechanisms in animals chronically treated with ethanol. Norepinephrine hydrochloride (0-12 ug intracerebroventricularly) produced dose-dependent diuresis in control and ethanol treated rats on the first day of treatment. Tolerance to ethanol diuresis was present after 10 day of ethanol treatment. Lack of responsiveness to norepinephrine-induced diuresis was evident only on the 20th day of treatment in both the ethanol and dextrin-maltose groups of rats. These results indicate a temporal dissociation between the tolerance to ethanol-induced and norepinephrine-induced diuresis and suggest that norepinephrine may not play a primary role in the development of tolerance to the diuretic action of ethanol.

  4. [Primary orthostatic hypotension].

    PubMed

    Lehmann, M; Hirsch, F W; Auch-Schwelk, W; Alnor, J; Ochs, A; Gastmann, U; Keul, J

    1986-02-01

    We studied a 25-year-old man suffering from primary orthostatic hypotension whose blood pressure decreased to 65/45 mm Hg during orthostasis and to 95/70 mm Hg during ergometric exercise (50 and 100 watt), and whose heart rate responses were inadequate. Resting catecholamine levels were within the normal range and did not show any significant increase related to orthostasis or to ergometric exercise. Hypersensitivity was observed to low doses of intravenous noradrenaline and isoproterenol. Specific binding of 3H-Yohimbine to intact platelets revealed a normal number of alpha-2-adrenoreceptors in agreement with the adrenaline-induced platelet aggregation in vitro, which was, however, in contrast to hypersensitivity to noradrenaline. Specific 3H-Dihydroalprenolol binding to intact polymorphonuclear leucocytes revealed an increased beta-2-adrenoreceptor density in agreement with hypersensitivity to Isoproterenol. Prescription of Fludrocortison improved orthostatic hypotension.

  5. Over-diuresis or cardiac tamponade? An unusual case of acute kidney injury and early closure

    PubMed Central

    Singh, Gurkeerat; Sabath, Bruce

    2016-01-01

    An 84-year-old man with hypertension and a history of deep venous thrombosis (on warfarin) was admitted with shortness of breath presumed to be due to congestive heart failure. Echocardiogram performed the following day showed a low-normal ejection fraction with signs of elevated right-sided pressures but was otherwise normal. He improved with diuretic therapy but after a few days was found to be hypotensive with a concomitant rise in creatinine with decreased urine output. This was felt to be secondary to over-diuresis but he did not respond to small boluses of intravenous fluids as his kidney function continued to worsen and hypotension persisted. He was transferred to the intermediate care unit where a rapid, bedside ultrasound revealed a new, moderate-sized pericardial effusion with tamponade physiology. Pericardiocentesis, with removal of 750 cc of frank blood, led to dramatic improvement in blood pressure, kidney function, and urine output. Here, we demonstrate the utility of point-of-care ultrasound in a community hospital setting where urgent echocardiogram is not routinely available. We also report acute kidney injury due to pericardial tamponade reversed with therapeutic pericardiocentesis. PMID:27124173

  6. Excess diuresis and natriuresis during acute sleep deprivation in healthy adults.

    PubMed

    Kamperis, Konstantinos; Hagstroem, Soren; Radvanska, Eva; Rittig, Soren; Djurhuus, Jens Christian

    2010-08-01

    The transition from wakefulness to sleep is associated with a pronounced decline in diuresis, a necessary physiological process that allows uninterrupted sleep. The aim of this study was to assess the effect of acute sleep deprivation (SD) on urine output and renal water, sodium, and solute handling in healthy young volunteers. Twenty young adults (10 male) were recruited for two 24-h studies under standardized dietary conditions. During one of the two admissions, subjects were deprived of sleep. Urine output, electrolyte excretions, and osmolar excretions were calculated. Activated renin, angiotensin II, aldosterone, arginine vasopressin, and atrial natriuretic peptide were measured in plasma, whereas prostaglandin E(2) and melatonin were measured in urine. SD markedly increased the diuresis and led to excess renal sodium excretion. The effect was more pronounced in men who shared significantly higher diuresis levels during SD compared with women. Renal water handling and arginine vasopressin levels remained unaltered during SD, but the circadian rhythm of the hormones of the renin-angiotensin-aldosterone system was significantly affected. Urinary melatonin and prostaglandin E(2) excretion levels were comparable between SD and baseline night. Hemodynamic changes were characterized by the attenuation of nocturnal blood pressure dipping and an increase in creatinine clearance. Acute deprivation of sleep induces natriuresis and osmotic diuresis, leading to excess nocturnal urine production, especially in men. Hemodynamic changes during SD may, through renal and hormonal processes, be responsible for these observations. Sleep architecture disturbances should be considered in clinical settings with nocturnal polyuria such as enuresis in children and nocturia in adults.

  7. Orthostatic hypotension for the cardiologist.

    PubMed

    Mar, Philip L; Raj, Satish R

    2017-10-04

    Orthostatic hypotension is a phenomenon commonly encountered in a cardiologist's clinical practice that has significant diagnostic and prognostic value for a cardiologist. Given the mounting evidence associating cardiovascular morbidity and mortality with orthostatic hypotension, cardiologists will play an increasing role in treating and managing patients with orthostatic hypotension. The American College of Cardiology, American Heart Association, and Heart Rhythm Society recently published consensus guidelines on the diagnosis, treatment, and management of syncope and their instigators, including orthostatic hypotension. Additionally, consensus guidelines have also been recently updated, reinforcing the universal definition orthostatic hypotension and its closely associated pathologies. Finally, the United States Food and Drug Administration (FDA) recently approved droxidopa, a synthetic oral norepinephrine prodrug, in 2014 for the treatment of neurogenic orthostatic hypotension (nOH), and it represents a well tolerated, effective, and easy to use intervention for nOH. This represents only the second drug approved by the FDA for orthostatic hypotension, the first being midodrine in 1986. A handful of smaller head-to-head studies have pitted not only pharmacologic agents to one another but also nonpharmacologic interventions to pharmacologic agents. Additionally, recent studies have also reported on more convenient screening tools for orthostatic hypotension. Though there have been many advances in the management of orthostatic hypotension, nOH remains a chronic, debilitating, and often progressively fatal condition. Cardiologists can play a very important role in optimizing hemodynamics in this patient population to improve quality of life and minimize cardiovascular risk.

  8. Causes of chronic orthostatic hypotension

    NASA Technical Reports Server (NTRS)

    Robertson, D.; Robertson, R. M.

    1994-01-01

    OBJECTIVE: To determine the frequency of various causes of orthostatic hypotension. DESIGN: Survey. SETTING: Tertiary referral center. PATIENTS: One hundred patients with moderate to severe orthostatic hypotension. RESULTS: Twenty-seven percent of the patients had primary autonomic failure, 35% had secondary autonomic failure, and 38% had hypotension without evidence of generalized autonomic degeneration. CONCLUSIONS: In a tertiary referral center, only a minority of patients with severe orthostatic hypotension will have Shy-Drager syndrome or Bradbury-Eggleston syndrome as their primary disease. Occasional patients who initially appear to have Bradbury-Eggleston syndrome ultimately prove to have Shy-Drager syndrome or paraneoplastic autonomic failure. Antidepressant drugs, even in low doses, remain a major overlooked cause of orthostatic hypotension.

  9. Hypotension in Severe Dimethoate Self-Poisoning

    PubMed Central

    Davies, James; Roberts, Darren; Eyer, Peter; Buckley, Nick; Eddleston, Michael

    2008-01-01

    Introduction Acute self-poisoning with the organophosphorus (OP) pesticide dimethoate has a human case fatality three-fold higher than poisoning with chlorpyrifos despite similar animal toxicity. The typical clinical presentation of severe dimethoate poisoning is quite distinct from that of chlorpyrifos and other OP pesticides: many patients present with hypotension that progresses to shock and death within 12–48 h post-ingestion. The pathophysiology of this syndrome is not clear. Case reports We present here three patients with proven severe dimethoate poisoning. Clinically, all had inappropriate peripheral vasodilatation and profound hypotension on presentation, which progressed despite treatment with atropine, i.v. fluids, pralidoxime chloride, and inotropes. All died 2.5–32 h post-admission. Continuous cardiac monitoring and quantification of troponin T provided little evidence for a primary cardiotoxic effect of dimethoate. Conclusion Severe dimethoate self-poisoning causes a syndrome characterized by marked hypotension with progression to distributive shock and death despite standard treatments. A lack of cardiotoxicity until just before death suggests that the mechanism is of OP-induced low systemic vascular resistance (SVR). Further invasive studies of cardiac function and SVR, and post-mortem histology, are required to better describe this syndrome and to establish the role of vasopressors and high-dose atropine in therapy. PMID:19003596

  10. Sustained hypotension following intravenous metoclopramide.

    PubMed

    Nguyen, Tammy T; Petzel Gimbar, Renee M

    2013-11-01

    To report a case of sustained hypotension associated with the use of intravenous metoclopramide. A 50-year-old woman developed a hypotensive episode lasting approximately 90 minutes after the administration intravenous metoclopramide for the treatment of a migraine. The patient presented to the emergency department after she woke up with a severe headache that was much worse than her normal migraine headaches. Her past medical history included migraines, diabetes type 2, hypertension, and hyperlipidemia. Fifteen minutes after the administration of intravenous metoclopramide 10 mg, the patient's systolic blood pressure decreased from 138 to 84 mmHg (a mean arterial pressure decrease of 40.7 mmHg). The patient was given 1 L of intravenous NaCl 0.9% that had minimal effect on blood pressure. The patient did not reapproach her baseline systolic blood pressure until 90 minutes after the metoclopramide administration when it was measured at 138 mmHg. Subsequent contrast tomography of the head was negative and the patient's headache was successfully treated with butalbital/acetaminophen/caffeine. The patient was discharged home the same day. There are few published case reports of metoclopramide-induced hypotension in the current literature. Of those published, all showed transient hypotension with metoclopramide, lasting seconds to minutes. An objective causality assessment for drug-associated adverse drug reaction showed metoclopramide as a probable cause of the patient's hypotension (Naranjo score of 5). In this case, several indicators of metoclopramide induced hypotension were evident, including the timing of the hypotension after drug administration and the lack of any other possible causes of hypotension. This is the first published case report of sustained hypotension due to intravenous metoclopramide. Intravenous metoclopramide may cause sustained episodes of hypotension.

  11. Treatment of Post-SCI Hypotension

    ClinicalTrials.gov

    2017-01-13

    Spinal Cord Injury; Autonomic Dysreflexia; Orthostatic Hypotension; Baroreceptor Integrity; Sympathetic Integrity; Vagal Integrity; Hypotension; Cerebral Blood Flow; Blood Pressure; Venous Occlusion Plethysmography

  12. Sleep deprivation induces excess diuresis and natriuresis in healthy children.

    PubMed

    Mahler, B; Kamperis, K; Schroeder, M; Frøkiær, J; Djurhuus, J C; Rittig, S

    2012-01-15

    Urine production is reduced at night, allowing undisturbed sleep. This study was undertaken to show the effect of sleep deprivation (SD) on urine production in healthy children. Special focus was on gender and children at an age where enuresis is still prominent. Twenty healthy children (10 girls) underwent two 24-h studies, randomly assigned to either sleep or SD on the first study night. Diet and fluid intake were standardized. Blood samples were drawn every 4 h during daytime and every 2 h at night. Urine was fractionally collected. Blood pressure and heart rate were noninvasively monitored. Blood was analyzed for plasma antidiuretic hormone (AVP), atrial natriuretic peptide (ANP), angiotensin II, aldosterone, and renin. Urine was analyzed for aquaporin-2 and PGE(2). Successful SD was achieved in all participants with a minimum of 4 h 50 min, and full-night SD was obtained in 50% of the participants. During SD, both boys and girls produced markedly larger amounts of urine than during normal sleep (477 ± 145 vs. 291 ± 86 ml, P < 0.01). SD increased urinary excretion of sodium (0.17 ± 0.05 vs. 0.10 ± 0.03 mmol·kg(-1)·h(-1)) whereas solute-free water reabsorption remained unchanged. SD induced a significant fall in nighttime plasma AVP (P < 0.01), renin (P < 0.05), angiotensin II (P < 0.001), and aldosterone (P < 0.05) whereas plasma ANP levels remained uninfluenced (P = 0.807). Nighttime blood pressure and heart rate were significantly higher during SD (mean arterial pressure: 78.5 ± 8.0 vs. 74.7 ± 8.7 mmHg, P < 0.001). SD leads to natriuresis and excess diuresis in healthy children. The underlying mechanism could be a reduced nighttime dip in blood pressure and a decrease in renin-angiotensin-aldosterone system levels during sleep deprivation.

  13. Five years of data diuresis: what have WEH learned?

    PubMed

    Sullivan, Jennifer C; Pollock, Jennifer S

    2015-11-01

    This year represents the fifth annual Data Diuresis session of the Water and Electrolyte Homeostasis (WEH) section of the American Physiological Society (APS) at the 2015 Experimental Biology meeting. As opposed to taking a single organ approach to the study of physiology, the WEH section employs an integrative approach to encompass how the different organ systems interact to regulate numerous physiological and pathophysiological processes. The goal of this minireview is to highlight the broad spectrum of research themes that were presented over the first five years of Data Diuresis. Presentation topics include (but are not limited to) oxidative stress, inflammation, obesity, pregnancy, and hypertension spanning the brain, heart and vasculature, and kidney. WEH researchers continue to impact and help drive the direction of physiological research across multiple disciplines, leaving us excited to see what the next five years of Data Diuresis will bring.

  14. Euglycemic Diabetic Ketoacidosis with Persistent Diuresis Treated with Canagliflozin.

    PubMed

    Adachi, Junichiro; Inaba, Yuusuke; Maki, Chisato

    2017-01-01

    Diabetic ketoacidosis is characterized by hyperglycemia, anion-gap acidosis, and increased plasma ketones. After the resolution of hyperglycemia, persistent diuresis is rare. We herein report the case of a 27-year-old Asian woman with type 2 diabetes who was treated with a sodium-glucose cotransporter 2 (SGLT2) inhibitor (canagliflozin) who developed euglycemic diabetic ketoacidosis and persistent diuresis in the absence of hyperglycemia. Physicians should consider euglycemic diabetic ketoacidosis in the differential diagnosis of patients treated with SGLT2 inhibitors.

  15. Euglycemic Diabetic Ketoacidosis with Persistent Diuresis Treated with Canagliflozin

    PubMed Central

    Adachi, Junichiro; Inaba, Yuusuke; Maki, Chisato

    2017-01-01

    Diabetic ketoacidosis is characterized by hyperglycemia, anion-gap acidosis, and increased plasma ketones. After the resolution of hyperglycemia, persistent diuresis is rare. We herein report the case of a 27-year-old Asian woman with type 2 diabetes who was treated with a sodium-glucose cotransporter 2 (SGLT2) inhibitor (canagliflozin) who developed euglycemic diabetic ketoacidosis and persistent diuresis in the absence of hyperglycemia. Physicians should consider euglycemic diabetic ketoacidosis in the differential diagnosis of patients treated with SGLT2 inhibitors. PMID:28090050

  16. [Orthostatic hypotension; that great unknown].

    PubMed

    Velilla-Zancada, S M; Prieto-Díaz, M A; Escobar-Cervantes, C; Manzano-Espinosa, L

    2016-11-16

    Orthostatic hypotension is an anomaly of growing interest in scientific research. Although certain neurogenic diseases are associated with this phenomenon, it can also be associated with non-neurological causes. Although orthostatic hypotension is defined by consensus as a decrease in the systolic blood pressure of at least 20mmHg, or a decrease in diastolic blood pressure of at least 10mmHg, within 3min of standing, the studies differ on how to diagnose it. Orthostatic hypotension is associated with certain cardiovascular risk factors and with drug treatment, but the results are contradictory. The purpose of this review is to update the knowledge about orthostatic hypotension and its treatment, as well as to propose a method to standardise its diagnosis.

  17. Hypotensive Resuscitation among Trauma Patients

    PubMed Central

    Carrick, Matthew M.; Leonard, Jan; Slone, Denetta S.; Mains, Charles W.

    2016-01-01

    Hemorrhagic shock is a principal cause of death among trauma patients within the first 24 hours after injury. Optimal fluid resuscitation strategies have been examined for nearly a century, more recently with several randomized controlled trials. Hypotensive resuscitation, also called permissive hypotension, is a resuscitation strategy that uses limited fluids and blood products during the early stages of treatment for hemorrhagic shock. A lower-than-normal blood pressure is maintained until operative control of the bleeding can occur. The randomized controlled trials examining restricted fluid resuscitation have demonstrated that aggressive fluid resuscitation in the prehospital and hospital setting leads to more complications than hypotensive resuscitation, with disparate findings on the survival benefit. Since the populations studied in each randomized controlled trial are slightly different, as is the timing of intervention and targeted vitals, there is still a need for a large, multicenter trial that can examine the benefit of hypotensive resuscitation in both blunt and penetrating trauma patients. PMID:27595109

  18. Primary neurogenic orthostatic hypotension

    PubMed Central

    Hughes, R. C.; Cartlidge, N. E. F.; Millac, P.

    1970-01-01

    Eight further cases of neurogenic orthostatic hypotension are described together with a necropsy study on one case. Three cases showed evidence of autonomic dysfunction in isolation, while in five cases this was accompanied by evidence of more diffuse central nervous system degeneration. (Parkinsonism, cerebellar ataxia, dementia, pyramidal signs, bulbar weakness, and muscular wasting were all seen in varying proportions.) The various clinical presentations, investigations, pathology, treatment, and prognosis are discussed. In the experience of the authors, when assessed, an abnormal Valsalva response is invariable, confirming the breakdown of the circulatory reflex. A normal vasopressor response is likewise invariable, eliminating an abnormality of blood vessels themselves, and confirming the lesion as neurogenic. The demonstration of loss of sweating to indirect body heating, which also is usual suggests that the defect is central or on the efferent side of the reflex and a normal pilo-erector response to acetylcholine confirms this as preganglionic. Emphasis is laid on the non-specificity of many accepted physiological tests in this disorder and on the delay in diagnosis consequent upon the variable presentation. PMID:5431725

  19. On the mechanisms of kappa-opioid-induced diuresis.

    PubMed Central

    Blackburn, T. P.; Borkowski, K. R.; Friend, J.; Rance, M. J.

    1986-01-01

    In conscious saline loaded rats, the kappa-opioid agonists tifluadom, U50488, and ethylketocyclazocine, given subcutaneously, induced a characteristic diuresis which could be antagonized by naloxone. Bilateral adrenal demedullation significantly reduced adrenal gland catecholamine content and plasma adrenaline levels, but did not significantly affect plasma corticosterone levels, indicating that the adrenal cortex remained both intact and functional. Seven days following bilateral adrenal demedullation, the subcutaneous administration of the kappa-agonists no longer induced diuresis. However, demedullation did not affect the diuretic response to frusemide or clonidine, nor did it affect the antidiuretic response induced by the mu-opioid agonists morphine and buprenorphine. Adrenal catecholamines do not appear to be involved in kappa-opioid-induced diuresis, since pretreatment with propranolol, prazosin and idazoxan did not affect the diuretic response in intact animals. The results indicate a link between the adrenal medulla and kappa-opioid-induced diuresis and suggest that a peripheral mechanism may also be involved in mediating this effect. PMID:3542107

  20. Osmotic and osmotic-loop diuresis in brain surgery. Effects on plasma and CSF electrolytes and ion excretion.

    PubMed

    Schettini, A; Stahurski, B; Young, H F

    1982-05-01

    In 22 patients to be operated on for brain tumors or cerebral aneurysms, the effect of osmotic diuresis was compared with that of osmotic-loop diuresis on plasma and cerebrospinal fluid (CSF) electrolytes, and water and ion excretion. Mannitol or mannitol plus furosemide were used to reduce brain bulk. After treatment with thiopental and hyperventilation, patients received randomly a rapid infusion of mannitol (1.4 gm/kg), or mannitol (1.4 gm/kg) plus furosemide (0.3 mg/kg). Brain shrinkage was considerably greater and more consistent with mannitol plus furosemide than with mannitol alone. However, hyponatremia, hypokalemia, hypochloremia, and hyperosmolality were also more marked (p less than 0.05) with mannitol plus furosemide than with mannitol. The rate of water and ion excretion was even more striking. At 30 minutes after absorption of mannitol alone, water excretion peaked at 17 ml/min, and gradually decreased to 3.8 ml/min 70 minutes later. With mannitol plus furosemide, during an identical time course, initial water excretion was 30 ml/min, followed by a further rise to 42 ml/min and then a decline to 17 ml/min. At peak diuresis after mannitol, Na+ and Cl- excretion average 0.57 and 0.62 mEq/min, respectively. This compares with mean values of 3.7 and 4.12 mEq/min for Na+ and Cl-, respectively, after mannitol plus furosemide. Although optimum brain shrinkage is achieved with osmotic-loop diuresis, the rapid electrolyte depletion (Na+ and Cl-) must be corrected to avoid altered sensorium during the patients' postoperative course.

  1. Midodrine for severe orthostatic hypotension.

    PubMed

    2016-05-01

    Midodrine (Bramox-Brancaster Pharma Limited) was authorised in the UK by the Medicines and Healthcare products Regulatory Agency (MHRA) in March 2015 for "the treatment of severe orthostatic hypotension due to autonomic dysfunction in adults when corrective factors have been ruled out and other forms of treatment are inadequate".(1) Previously, midodrine had only been available in the UK as an unlicensed product used on a named-patient basis. It is the first drug to be licensed in the UK for the treatment of orthostatic hypotension. Here we consider the evidence for midodrine in the treatment of severe orthostatic hypotension and how it fits with current management strategies. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  2. [Clinical experimental studies in patients with asympathicotonic hypotension].

    PubMed

    Anlauf, M; Werner, U; Merguet, P; Nitzs, T; Graben, N; Bock, K D

    1975-04-25

    Three patients with postural hypotension (two of the idiopathic type, one possibly due to familial dysautonomia) were found to have not only the pathognomonic postural hypotension, without rise in heart rate, cardiac output and peripheral vascular resistance, but also a similarly abnormal regulatory mechanism on ergometric stress when recumbent. There was a delayed-response to the bloodpressure fall on Valsalva a manoeuvre, and the blood volume was reduced. A combined effect of these factors explains that these patients have a more marked impairment of physical capcity than might be expected merely from the orthostatic hypotension. The actions of noradrenaline, adrenaline, phenylephrine, isoproterenol, angiotensin and tyramine on blood pressure and heart rate were different from normal. Plasma-renin activity was reduced in all three patients and could not be raised. Urinary excretion of adrenaline and noradrenaline was markedly diminished. Reactions to noradrenaline and tyramine, as well as the excretion pattern of the catecholamine metabolites suggest a disorder of active adrenaline liberation. Furthermore, different disorders of catecholamine metabolism underlie idiopathic orthostatic hypotension and familial autonomia. Therapeutic trials with fludrocortisone, beta-receptor blockers and levodopa brought improvement, but long-term results are not yet available.

  3. Hypotension Begins at 110 mm Hg: Redefining Hypotension With Data

    DTIC Science & Technology

    2007-08-19

    turn the paper around a bit and look at it from the therapeutic side. For years now we’ve been talking about hypotensive resuscitation and the...a café napkin , we theorized on what is the level of blood pressure. Howard Champion reminded us of Bill Seiko’s work in Baltimore, and Frank Lewis

  4. Postprandial and Orthostatic Hypotension Treated by Sitagliptin in a Patient with Dementia with Lewy Bodies

    PubMed Central

    Saito, Yoshihiro; Ishikawa, Joji; Harada, Kazumasa

    2016-01-01

    Patient: Female, 78 Final Diagnosis: Dementia with Lewy body Symptoms: Dizziness • sycope Medication: — Clinical Procedure: — Specialty: Geriatrics Objective: Unusual setting of medical care Background: Postprandial hypotension, induced by an absorption of glucose from intestine, could be treated by acarbose; however, it was unclear whether dipeptidyl peptidase-4 inhibitor reduced postprandial hypotension. Case Report: A 78-year-old woman who had experienced episodes of dizziness and hypotension after eating was admitted to our hospital. During 24-hour ambulatory blood pressure monitoring, there were repeated episodes of marked postprandial hypotension; i.e., a significant systolic blood pressure reduction within two hours after eating (from ‒58 to ‒64 mm Hg after meals). The patient was diagnosed with dementia with Lewy bodies. The patient exhibited postprandial hyperglycemia and hypotension after a 75 g oral glucose tolerance test. After the administration of 25 mg sitagliptin, the patient’s postprandial and orthostatic hypotension was reduced remarkably. Moreover, her Mini-Mental State Examination score subsequently increased (from 22 to 25 points). Conclusions: The dipeptidyl peptidase-4 inhibitor sitagliptin can delay postprandial increases in glucose levels and hypotensive episodes, as well as sympathetic nervous system abnormalities and orthostatic hypotension. PMID:27885251

  5. Guidance document for structured reporting of diuresis renography.

    PubMed

    Taylor, Andrew T; Blaufox, M Donald; De Palma, Diego; Dubovsky, Eva V; Erbaş, Belkis; Eskild-Jensen, Anni; Frøkiær, Jørgen; Issa, Muta M; Piepsz, Amy; Prigent, Alain

    2012-01-01

    This Guidance Document for structured reporting of diuresis renography in adults was developed by the International Scientific Committee of Radionuclides in Nephro-urology (ISCORN; http://www.iscorn.org). ISCORN chose diuresis renography for its first structured report Guidance Document because suspected obstruction is the most common reason for referral, most radionuclide renal studies are conducted at institutions that perform fewer than 3 studies per week, and a large percentage of studies are interpreted by physicians with limited training in nuclear medicine. Ten panelists were asked to categorize specific reporting elements as essential, recommended, optional (without sufficient data to support a higher ranking), and unnecessary (does not contribute to scan interpretation or quality assurance). The final document was developed through an iterative series of comments and questionnaires with a majority vote required to place an element in a specific category. The Guidance Document recommends a reporting structure organized into indications, clinical history, study procedure, findings and impression and specifies the elements considered essential or recommended in each category. The Guidance Document is not intended to be restrictive but, rather, to provide a basic structure and rationale so that the diuresis renography report will: (1) communicate the results to the referring physician in a clear and concise manner designed to optimize patient care; (2) contain the essential elements required to evaluate and interpret the study; (3) clearly document the technical components of the study necessary for accountability, quality assurance and reimbursement; and (4) encourage clinical research by facilitating better comparison and extrapolation of results between institutions.

  6. Regulation of arterial pressure: role of pressure natriuresis and diuresis.

    PubMed

    Hall, J E; Guyton, A C; Coleman, T G; Mizelle, H L; Woods, L L

    1986-12-01

    The importance of the renal pressure natriuresis and diuresis mechanisms in long-term control of body fluid volumes and arterial pressure has been controversial and difficult to quantitate experimentally. Recent studies, however, have demonstrated that in several forms of chronic hypertension caused by aldosterone, angiotensin II (AngII), vasopressin, or norepinephrine and adrenocorticotropin, increased renal arterial pressure is essential for maintaining normal excretion of sodium and water in the face of reduced renal excretory capability. When renal arterial pressure was servo-controlled in these models of hypertension, sodium and water retention continued unabated, causing ascites, pulmonary edema, or even complete circulatory collapse within a few days. Apparently, other mechanisms for volume homeostasis, such as the various natriuretic and diuretic factors that have been postulated, are not sufficiently powerful to maintain fluid balance in the absence of increased renal arterial pressure when renal excretory function is reduced in these forms of hypertension. The intrarenal mechanisms responsible for pressure natriuresis and diuresis are not entirely clear, but they seem to involve small increases in glomerular filtration rate and filtered load as well as reductions in fractional reabsorption in proximal and distal tubules. During chronic disturbances of arterial pressure additional factors, especially changes in AngII and aldosterone formation, act to amplify the effectiveness of the basic renal pressure natriuresis and diuresis mechanisms in regulating arterial pressure and body fluid volumes.

  7. Atrial natriuretic peptide blocks renin response to renal hypotension

    SciTech Connect

    Scheuer, D.A.; Thrasher, T.N.; Quillen, E.W. Jr.; Metzler, C.H.; Ramsay, D.J.

    1987-02-01

    The authors have reported that the renin response to systemic hypotension is inhibited in the presence of elevated atrial pressure and that elevations in atrial pressure of similar or larger magnitude cause graded increases in plasma atrial natriuretic peptide (ANP). Therefore they tested the hypothesis that comparable increments in plasma ANP can inhibit renal hypotension-induced increases in plasma renin activity (PRA) in conscious dogs. Renal perfusion pressure was controlled using cuffs implanted around the abdominal aorta just above the renal arteries. Reducing renal perfusion pressure by 10 or 30% of control caused graded increases in PRA. Infusion of 1-28 rat ANP, which increased plasma ANP by 34.8 +/- 7.5 (SE) pg/ml, eliminated increases in PRA in response to a 10% reduction in renal perfusion pressure and markedly inhibited the response to a 30% pressure reduction. ANP and PRA were measured by radioimmunoassay. These results indicate that increments in plasma ANP which reproduce endogenous release inhibit renal hypotension-induced stimulation of PRA. Furthermore, the results provide an explanation for the inhibition of the renin response to renal hypotension during elevate atrial pressure.

  8. On the mechanism of L-DOPA-induced postural hypotension in the cat

    PubMed Central

    Dhasmana, K. M.; Spilker, B. A.

    1973-01-01

    1. The effects of L-DOPA on postural hypotension and carotid occlusion pressor effect were studied, mainly in cats; the recovery of the blood pressure upon tilting was used as a measure of postural hypotension. 2. L-DOPA (30 mg/kg) partially depressed the carotid occlusion pressor effect and caused some degree of postural hypotension, L-DOPA (100 mg/kg) had more marked effects; the responses returned to control after 90 to 150 minutes. L-DOPA itself caused a pressor response in all cats. 3. The dopa decarboxylase inhibitor N1-(DL-seryl)-N2-(2,3,4-trihydroxybenzyl) hydrazine (RO4-4602, 50 and 10 mg/kg) had no effect itself on the tilt response but completely prevented the effects of L-DOPA on the carotid occlusion pressor effect and postural hypotension. 4. After RO4-4602 (3 and 1 mg/kg), L-DOPA (100 mg/kg) caused a brief rise of blood pressure followed by a longer lasting fall in horizontally-orientated cats (i.e. `supine' hypotension). No postural hypotension was observed after L-DOPA under these conditions. 5. Noradrenaline elicited only small and transient effects on postural hypotension, but dopamine's effects were more marked and longer lasting. Pressor dose-response relationships for noradrenaline were the same before and after L-DOPA, as well as in cats pretreated with L-DOPA for 4 days. 6. In cats with kidneys and intestines removed, the tilt reflex was still present. Dose-response curves to L-DOPA were the same as in normal animals. RO4-4602 (3 mg/kg) prevented postural hypotension and block of the carotid occlusion pressor effect; supine hypotension was also observed after L-DOPA. 7. The recovery response to tilting in spinal cats was markedly depressed or absent unless the blood pressure was elevated by angiotensin, in which experiments L-DOPA depressed the recovery upon tilting (i.e. induced postural hypotension). 8. Blood pressure responses to tyramine were increased after 10 mg/kg of L-DOPA, but depressed after 100 mg/kg. The response to tyramine was

  9. Magnesium Sulfate: Another Cause of a Solute Diuresis.

    PubMed

    Brown, Robert S

    2017-04-01

    In pregnant women, magnesium sulfate infusions are a treatment commonly used for preeclampsia and as a tocolytic agent. In this case report, a 33-year-old woman at 26 weeks of gestation received intravenous magnesium sulfate in Ringer's lactate solution and corticosteroids for preterm uterine contractions without preeclampsia. She developed polyuria of more than 18L in 48 hours, with urine chemistries documenting that magnesium sulfate contributed 30% of the solute in this massive isosthenuric diuresis. Therefore, magnesium sulfate should be added to the common solutes, glucose, sodium chloride, urea, and mannitol, as a cause of solute diureses. Copyright © 2016 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

  10. The non-diuretic hypotensive effects of thiazides are enhanced during volume depletion states

    PubMed Central

    Alshahrani, Saeed; Rapoport, Robert M.; Zahedi, Kamyar; Jiang, Min; Nieman, Michelle; Barone, Sharon; Meredith, Andrea L.; Lorenz, John N.; Rubinstein, Jack

    2017-01-01

    Thiazide derivatives including Hydrochlorothiazide (HCTZ) represent the most common treatment of mild to moderate hypertension. Thiazides initially enhance diuresis via inhibition of the kidney Na+-Cl- Cotransporter (NCC). However, chronic volume depletion and diuresis are minimal while lowered blood pressure (BP) is maintained on thiazides. Thus, a vasodilator action of thiazides is proposed, likely via Ca2+-activated K+ (BK) channels in vascular smooth muscles. This study ascertains the role of volume depletion induced by salt restriction or salt wasting in NCC KO mice on the non-diuretic hypotensive action of HCTZ. HCTZ (20mg/kg s.c.) lowered BP in 1) NCC KO on a salt restricted diet but not with normal diet; 2) in volume depleted but not in volume resuscitated pendrin/NCC dKO mice; the BP reduction occurs without any enhancement in salt excretion or reduction in cardiac output. HCTZ still lowered BP following treatment of NCC KO on salt restricted diet with paxilline (8 mg/kg, i.p.), a BK channel blocker, and in BK KO and BK/NCC dKO mice on salt restricted diet. In aortic rings from NCC KO mice on normal and low salt diet, HCTZ did not alter and minimally decreased maximal phenylephrine contraction, respectively, while contractile sensitivity remained unchanged. These results demonstrate 1) the non-diuretic hypotensive effects of thiazides are augmented with volume depletion and 2) that the BP reduction is likely the result of HCTZ inhibition of vasoconstriction through a pathway dependent on factors present in vivo, is unrelated to BK channel activation, and involves processes associated with intravascular volume depletion. PMID:28719636

  11. Lysosphingolipid receptor-mediated diuresis and natriuresis in anaesthetized rats.

    PubMed

    Bischoff, A; Meyer Zu Heringdorf, D; Jakobs, K H; Michel, M C

    2001-04-01

    Lysosphingolipids such as sphingosine-1-phosphate (SPP) and sphingosylphosphorylcholine (SPPC) can act on specific G-protein-coupled receptors. Since SPP and SPPC cause renal vasoconstriction, we have investigated their effects on urine and electrolyte excretion in anaesthetized rats. Infusion of SPP (1 - 30 microg kg(-1) min(-1)) for up to 120 min dose-dependently but transiently (peak after 15 min, disappearance after 60 min) reduced renal blood flow without altering endogenous creatinine clearance. Nevertheless, infusion of SPP increased diuresis, natriuresis and calciuresis and, to a lesser extent, kaliuresis. These tubular lysosphingolipid effects developed more slowly (maximum after 60 - 90 min) and also abated more slowly upon lysosphingolipid washout than the renovascular effects. Infusion of SPPC, sphingosine and glucopsychosine (3 - 30 microg kg(-1) min(-1) each) caused little if any alterations in renal blood flow but also increased diuresis, natriuresis and calciuresis and, to a lesser extent, kaliuresis. Pretreatment with pertussis toxin (10 microg kg(-1) 3 days before the acute experiment) abolished the renovascular and tubular effects of 30 microg kg(-1) min(-1) SPP. These findings suggest that lysosphingolipids are a hitherto unrecognized class of endogenous modulators of renal function. SPP affects renovascular tone and tubular function via receptors coupled to G(i)-type G-proteins. SPPC, sphingosine and glucopsychosine mimic only the tubular effects of SPP, and hence may act on distinct sites.

  12. Sex differences in pressure diuresis/natriuresis in rabbits.

    PubMed

    Evans, R G; Stevenson, K M; Bergström, G; Denton, K M; Madden, A C; Gribben, R L; Weekes, S R; Anderson, W P

    2000-08-01

    We tested for sex-related differences in the pressure diuresis/natriuresis relationships in anaesthetized, renally denervated rabbits, using an extracorporeal circuit to perfuse the left kidney with the rabbit's own blood, through a series of step-wise increases in renal artery pressure (RAP) (from 65 to 130 mmHg). Urine flow, sodium excretion, and the fractional excretions of sodium and urine increased with increasing RAP, and were greater in male than in female rabbits at all levels of RAP-tested. However, these apparent sex-related differences in the acute pressure diuresis/natriuresis relationships were not reflected in alterations in chronic regulation of mean arterial pressure (MAP). Thus, in rabbits on a normal salt diet (0.85 g day(-1)), resting conscious MAP was significantly greater in males (87 +/- 3 mmHg) compared with females (77+/-1 mmHg). Chronically increasing daily salt intake to 4.98 g day(-1) for 28 days had no significant effect on resting conscious MAP in either sex. Thus, although our observations indicate sex differences, at least under the present experimental conditions, in the factors regulating extracellular fluid volume, these do not appear to have a major impact in setting the level of MAP in the long term.

  13. [Role of prostaglandin E2 in regulation of urine excretion in saluresis, water and osmotic diuresis in rat].

    PubMed

    Bogolepova, A E; Shakhmatova, E I

    2004-11-01

    In the saluresis, water and osmotic diuresis were indicating an increase of prostaglandin E2 excretion and a correlation between this index and diuresis. Unselective blockade of cyclooxygenase by diclofenac-natrium leads to a decrease of diuresis in the observed types of urine-production in rats. Inhibition of inducible cyclooxygenase by celebrex didn't change the value of diuresis after water load or administration of osmotic agent, but decreased the diuretic effect of furosemide.

  14. Orthostatic hypotension: epidemiology, pathophysiology and management

    NASA Technical Reports Server (NTRS)

    Jacob, G.; Robertson, D.

    1995-01-01

    Orthostatic hypotension is characterized by low upright blood pressure levels and symptoms of cerebral hypoperfusion. Whereas orthostatic hypotension is heterogeneous, correct pathophysiologic diagnosis is important because of therapeutic and prognostic considerations. Although therapy is not usually curative, it can be extraordinarily beneficial if it is individually tailored. Management of the Shy-Drager syndrome (multiple-system atrophy) remains a formidable challenge.

  15. Alternating Skew Deviation from Traumatic Intracranial Hypotension

    PubMed Central

    Moster, Stephen J.; Moster, Mark L.

    2014-01-01

    Abstract A 56-year-old woman developed progressive headache, mental status changes, and diplopia after trauma. She was diagnosed with alternating skew deviation caused by intracranial hypotension. This is the first case of alternating skew deviation reported from intracranial hypotension and perhaps a differential pressure between intracranial and intraspinal spaces plays a role in the development of these findings. PMID:27928294

  16. Orthostatic hypotension: epidemiology, pathophysiology and management

    NASA Technical Reports Server (NTRS)

    Jacob, G.; Robertson, D.

    1995-01-01

    Orthostatic hypotension is characterized by low upright blood pressure levels and symptoms of cerebral hypoperfusion. Whereas orthostatic hypotension is heterogeneous, correct pathophysiologic diagnosis is important because of therapeutic and prognostic considerations. Although therapy is not usually curative, it can be extraordinarily beneficial if it is individually tailored. Management of the Shy-Drager syndrome (multiple-system atrophy) remains a formidable challenge.

  17. The principles and technical aspects of diuresis renography

    SciTech Connect

    Conway, J.J. )

    1989-12-01

    It is intuitive that dilation of the urinary tract is most likely caused by obstruction. However, the opposite is more often true. That is, dilation is not associated with obstruction, especially in children. The most common causes for hydronephrosis and hydroureter include infection, vesicoureteral reflux, congenital megacalyces and megaureter, previous obstruction, and bladder noncompliance. Theoretically, one can consider obstruction on the basis of its significance, which is that there may be a loss of renal function with time. Techniques such as intravenous pyelography and ultrasonography, which anatomically document the degree of dilation of the urinary tract, cannot quantitatively determine the presence of obstruction or its significance. Radionuclide renography more readily quantifies abnormal renal function. Serial renographic studies with furosemide can document renal function loss and, thus, determine the significance of the obstruction. Diuresis renography with furosemide provides an objective quantitative means for determining the renal function changes over time.

  18. Studies on the adrenomedullary dependence of kappa-opioid agonist-induced diuresis in conscious rats.

    PubMed Central

    Borkowski, K. R.

    1989-01-01

    1. The dependence of kappa-opioid agonist-induced diuresis, upon an intact and functional adrenal medulla in conscious rats, was investigated in order to test the hypothesis that the diuresis is mediated by a blood-borne 'diuretic factor', of adrenomedullary origin, released by kappa-opioid receptor stimulation. 2. Confirming previous observations, adrenal demedullation significantly attenuated diuretic responses to the kappa-opioid agonists U50488H, ethylketocyclazocine (EKC) and tifluadom, but did not affect basal urine output, furosemide-induced diuresis or the antidiuretic response to the mu-opioid agonist, buprenorphine. Naloxone abolished U50488H-induced diuresis, confirming an involvement of opioid receptors. 3. Transfusion studies established that blood, from intact rats treated with U50488H, induced diuresis in intact and demedullated recipient rats, whether or not the recipients had been pretreated with naloxone. However, blood from demedullated rats treated with U50448H was unable to induce diuresis when administered to intact or demedullated recipients. 4. It is concluded that kappa-opioid agonist-induced diuresis is dependent upon an intact and functional adrenal medulla and appears to be mediated by a blood-borne 'diuretic factor' of adrenomedullary origin. PMID:2558758

  19. Caffeine-induced diuresis and atrial natriuretic peptides.

    PubMed

    Nussberger, J; Mooser, V; Maridor, G; Juillerat, L; Waeber, B; Brunner, H R

    1990-05-01

    After a single-blind, randomized, cross-over protocol using decaffeinated coffee in a control experiment, the effect of an oral 250-mg caffeine dose on plasma immunoreactive atrial natriuretic peptide (ANF) was assessed in eight healthy students who had been on a methylxanthine-free diet for 1 week. One to 2 h after caffeine ingestion, both systolic blood pressure (SBP) and diastolic BP (DBP) increased by 12 mm Hg while heart rate (HR) also tended to increase. An increase in diuresis and in urinary sodium, potassium, and osmol excretion was observed within 1 h. Decaffeinated coffee induced no change in any of these parameters. Plasma epinephrine (EPI) increased gradually from 16.6 +/- 3.2 pg/ml (mean +/- SEM) to 45.1 +/- 7.9 pg/ml within 2 h after caffeine ingestion, but did not change after decaffeinated coffee (p less than 0.001). Plasma norepinephrine (NE), renin activity (PRA), aldosterone, and vasopressin remained unchanged. Plasma ANF was measured by radioimmunoassay (RIA) using an extremely sensitive antiserum (Kd = 10(-12) M) after rapid and virtually complete (90-103%) extraction from plasma. In 0.2 ml plasma, the theoretical detection limit is 1.1 fmol/ml. Normal plasma ANF concentrations in supine subjects were 17.9 +/- 8.1 fmol/ml (mean +/- SD) and 11.0 +/- 3.3 fmol/ml in subjects in the upright position. Plasma ANF levels were not affected by coffee drinking. In conclusion, by using a new and sensitive assay for plasma ANF, we did not find that caffeine-induced diuresis is mediated by ANF.

  20. Droxidopa in neurogenic orthostatic hypotension

    PubMed Central

    Kaufmann, Horacio; Norcliffe-Kaufmann, Lucy; Palma, Jose-Alberto

    2015-01-01

    Neurogenic orthostatic hypotension (nOH) is a fall in blood pressure on standing due to reduced norepinephrine release from sympathetic nerve terminals. nOH is a feature of several neurological disorders that affect the autonomic nervous system, most notably Parkinson disease (PD), multiple system atrophy, pure autonomic failure and other autonomic neuropathies. Droxidopa, an orally active synthetic amino acid that is converted to norepinephrine by the enzyme aromatic L-amino acid decarboxylase (dopa-decarboxylase), was recently approved by the FDA for the short-term treatment of nOH. It is presumed to raise blood pressure by acting at the neurovascular junction to increase vascular tone. This review summarizes the pharmacological properties of droxidopa, its mechanism of action, and the efficacy and safety results of clinical trials. PMID:26092297

  1. Gastric vascular and motor responses to anaphylactic hypotension in anesthetized rats, in comparison to those with hemorrhagic or vasodilator-induced hypotension.

    PubMed

    Kuda, Yuhichi; Shibamoto, Toshishige; Zhang, Tao; Yang, Wei; Tanida, Mamoru; Kurata, Yasutaka

    2017-01-31

    Anaphylactic shock is life-threatening, but pathophysiology of the stomach lesion remains unclear. We determined gastric hemodynamics and gastric functions during anaphylactic hypotension, as compared to hypotension induced by hemorrhage or sodium nitroprusside (SNP) in anesthetized and ovalbumin-sensitized Sprague-Dawley rats. Systemic arterial pressure, portal venous pressure, and gastric arterial blood flow were measured, and gastric vascular resistance (GVR) was determined. Separately, the intragastric pressure (IGP) and gastric effluent, as a measure of gastric flux, were continuously measured. During anaphylaxis, GVR decreased only transiently at 0.5 min, followed by an increase. IGP increased markedly, while gastric flux decreased. During hemorrhage, GVR and IGP increased, while gastric flux did not change. When SNP was injected, both GVR and IGP decreased and gastric flux increased only just after injection. In conclusion, gastric vasodilatation occurs only transiently after antigen injection, and gastric motility increases, but gastric emptying deceases during anaphylactic hypotension in anesthetized rats.

  2. A C-terminal Aldehyde Analog of the Insect Kinins Inhibits Diuresis in the Housefly

    DTIC Science & Technology

    2006-09-21

    p e p t i d e s 2 8 ( 2 0 0 7 ) 1 4 6 – 1 5 2A C-terminal aldehyde analog of the insect kinins inhibits diuresis in the housefly Ronald J. Nachman a...secretion in crickets, but shows inhibition of both in vitro and in vivo diuresis in the housefly. R-LK-CHO reduced the total amount of urine voided over 3 h...to stimulate Malpighian tubule fluid secretion [2,25]. In the housefly, muscakinin has been implicated in the control of diuresis in response to

  3. Effects of daily water drinking on orthostatic and postprandial hypotension in patients with multiple system atrophy.

    PubMed

    Deguchi, Kazushi; Ikeda, Kazuyo; Sasaki, Iwao; Shimamura, Mieko; Urai, Yoshiteru; Tsukaguchi, Masago; Touge, Tetsuo; Takeuchi, Hiroaki; Kuriyama, Shigeki

    2007-06-01

    It has been demonstrated that the increased blood pressure (BP) caused by a single dose of water alleviates orthostatic hypotension (OH) and postprandial hypotension (PPH) in patients with autonomic failure (AF). The aim of this study was to evaluate the practical effect of daily water drinking on OH and PPH in the morning when patients with AF are usually most affected. In five patients with multiple system atrophy (MSA) characterized by intractable OH and PPH, we measured seated, standing and postprandial BP in the morning without and with ingestion of 350 ml tap water at 07.30 hours for seven successive days. The changes from the basal BP level at 07.30 hours (DeltaBP) were assessed as an index of the effect of water drinking. Water drinking elicited a rapid pressor response in all patients. The DeltaBP during sitting, standing and after a meal following water drinking (day 1 and day 7) was significantly higher than without water drinking (day 0). The effects of reducing OH and PPH on day 7 were equivalent to those on day 1. No adverse effects associated with daily water drinking were observed, except later diuresis, which occurred in one patient. Daily water drinking demonstrated constant pressor effects in the morning with no severe adverse effects in MSA patients. This finding suggests that water drinking should be tried as a practical measure to prevent or reduce OH and PPH.

  4. Hypotension in ICU Patients Receiving Vasopressor Therapy.

    PubMed

    Yapps, Bryce; Shin, Sungtae; Bighamian, Ramin; Thorsen, Jill; Arsenault, Colleen; Quraishi, Sadeq A; Hahn, Jin-Oh; Reisner, Andrew T

    2017-08-17

    Vasopressor infusion (VPI) is used to treat hypotension in an ICU. We studied compliance with blood pressure (BP) goals during VPI and whether a statistical model might be efficacious for advance warning of impending hypotension, compared with a basic hypotension threshold alert. Retrospective data were obtained from a public database. Studying adult ICU patients receiving VPI at submaximal dosages, we analyzed characteristics of sustained hypotension episodes (>15 min) and then developed a logistic regression model to predict hypotension episodes using input features related to BP trends. The model was then validated with prospective data. In the retrospective dataset, 102-of-215 ICU stays experienced >1 hypotension episode (median of 2.5 episodes per day in this subgroup). When trained with 75% of retrospective dataset, testing with the remaining 25% of the dataset showed that the model and the threshold alert detected 99.6% and 100% of the episodes, respectively, with median advance forecast times (AFT) of 12 and 0 min. In a second, prospective dataset, the model detected 100% of 26 episodes with a median AFT of 22 min. In conclusion, episodes of hypotension were common during VPI in the ICU. A logistic regression model using BP temporal trend features predicted the episodes before their onset.

  5. Stress induced hypotension in pure autonomic failure

    PubMed Central

    Thijs, R D; van Dijk, J G

    2006-01-01

    A 47 year old woman with pure autonomic failure complained of dizziness during emotional stress. Emotional stimuli have not previously been reported to cause hypotension in patients with autonomic failure. In the patient, ambulatory blood pressure recording revealed severe hypotension (50/30 mm Hg) after a stressful event. During a tilt table test, hyperventilation was shown to cause a significant fall of blood pressure. This suggests that emotional stress can induce hypotension, probably through hyperventilation, in subjects with autonomic failure. PMID:16354738

  6. RNAi-mediated gene knockdown and in vivo diuresis assay in adult female Aedes aegypti mosquitoes.

    PubMed

    Drake, Lisa L; Price, David P; Aguirre, Sarah E; Hansen, Immo A

    2012-07-14

    This video protocol demonstrates an effective technique to knockdown a particular gene in an insect and conduct a novel bioassay to measure excretion rate. This method can be used to obtain a better understanding of the process of diuresis in insects and is especially useful in the study of diuresis in blood-feeding arthropods that are able to take up huge amounts of liquid in a single blood meal. This RNAi-mediated gene knockdown combined with an in vivo diuresis assay was developed by the Hansen lab to study the effects of RNAi-mediated knockdown of aquaporin genes on Aedes aegypti mosquito diuresis. The protocol is setup in two parts: the first demonstration illustrates how to construct a simple mosquito injection device and how to prepare and inject dsRNA into the thorax of mosquitoes for RNAi-mediated gene knockdown. The second demonstration illustrates how to determine excretion rates in mosquitoes using an in vivo bioassay.

  7. Sympathoinhibition and hypotension in carotid sinus hypersensitivity

    NASA Technical Reports Server (NTRS)

    Smith, M. L.; Ellenbogen, K. A.; Eckberg, D. L.

    1992-01-01

    Carotid sinus reflex hypersensitivity is a known cause of syncope in humans. The condition is characterized by cardioinhibition and vasodepression, each to varying degrees. The extent and importance of sympathoinhibition has not been determined in patients with carotid sinus hypersensitivity. This study reports on the extent of sympathoinhibition measured directly directly during carotid massage with and without atrioventricular sequential pacing, in a patient with symptomatic carotid sinus reflex hypersensitivity. Carotid massage elicited asystole, hypotension and complete inhibition of muscle sympathetic nerve activity. Carotid massage during atrioventricular pacing produced similar sympathoinhibition, but with minimal hypotension. Therefore, sympathoinhibition did not contribute importantly to the hypotension during carotid massage in the supine position in this patient. Further investigations are required to elucidate the relation of sympathoinhibition to hypotension in patients with carotid sinus hypersensitivity in the upright position.

  8. Sympathoinhibition and hypotension in carotid sinus hypersensitivity

    NASA Technical Reports Server (NTRS)

    Smith, M. L.; Ellenbogen, K. A.; Eckberg, D. L.

    1992-01-01

    Carotid sinus reflex hypersensitivity is a known cause of syncope in humans. The condition is characterized by cardioinhibition and vasodepression, each to varying degrees. The extent and importance of sympathoinhibition has not been determined in patients with carotid sinus hypersensitivity. This study reports on the extent of sympathoinhibition measured directly directly during carotid massage with and without atrioventricular sequential pacing, in a patient with symptomatic carotid sinus reflex hypersensitivity. Carotid massage elicited asystole, hypotension and complete inhibition of muscle sympathetic nerve activity. Carotid massage during atrioventricular pacing produced similar sympathoinhibition, but with minimal hypotension. Therefore, sympathoinhibition did not contribute importantly to the hypotension during carotid massage in the supine position in this patient. Further investigations are required to elucidate the relation of sympathoinhibition to hypotension in patients with carotid sinus hypersensitivity in the upright position.

  9. Is clonidine-induced diuresis mediated by atrial natriuretic factor?

    PubMed

    Pan, L; Gutkowska, J

    1988-09-01

    The effect of intracerebroventricular (ICV) administration of clonidine on urine output, urinary sodium excretion, urinary cGMP, and plasma immunoreactive atrial natriuretic factor (IR-ANF) was studied in conscious, normally hydrated rats. Clonidine treatment evoked a significant dose-dependent increase in urine output. A 20-fold elevation was noted after the highest clonidine dose (2 micrograms/rat). The observed diuresis was accompanied by enhanced sodium excretion, which with the highest dose (2 micrograms) of clonidine increased from 1.6 +/- 0.36 to 39.4 +/- 10.5 meq/liter (P less than 0.001). Plasma IR-ANF rose from 30.7 +/- 8.8 to 113.3 +/- 32.3 pg/ml plasma 5 min after the 0.5 micrograms clonidine dose (P less than 0.05), and urinary cGMP excretion was augmented from 8.49 +/- 4.29 to 27.7 +/- 5.0 pmol/min 1 h after 0.5 micrograms clonidine (P less than 0.05). Pretreatment with peripherally administered anti-ANF serum abolished the diuretic effect of intracerebroventricularly administered clonidine; urine output decreased from 1.49 +/- 0.41 to 0.42 +/- 0.21 ml/h. The urinary cGMP level after anti-ANF serum treatment fell from 25.0 +/- 7.56 to 7.1 +/- 3.5 pmol/min (P less than 0.05). Peripheral pretreatment with the alpha 2-antagonist yohimbine or the opioid antagonist naloxone partially abolished clonidine's diuretic impact: urine output dropped from 1.91 +/- 0.55 to 0.42 +/- 0.18 and 0.46 +/- 0.18 ml/h (P less than 0.05), respectively. At the same time, plasma IR-ANF decreased from 113.3 +/- 32.2 to 30.3 +/- 11.4 after yohimbine and to 24.6 +/- 12.1 pg/ml after naloxone treatment (P less than 0.05). These data suggest that ANF may be involved in the mechanism of diuresis of centrally applied clonidine, which appears to enhance ANF release through its central stimulation of opiate and alpha 2-adrenergic receptors.

  10. [Orthostatic hypotension in the elderly].

    PubMed

    Ferrer-Gila, Teresa; Rízea, Cristian

    2013-03-16

    Orthostatic hypotension (OH) is defined as a decrease in systolic blood pressure of 20 mmHg, or a decrease in diastolic blood pressure of 10 mmHg within three minutes of standing. It results from an inadequate response to postural changes in blood pressure. Common symptoms include dizziness, light-headedness, blurred vision, weakness, fatigue, nausea, palpitations, sweating, head and neck ache, slow cognitive performance and transient loss of conscientiousness. OH is a common problem among elderly patients and its aetiology is diverse, including autonomic nervous system dysfunction, cardiac problems, medication side effects, ageing changes or transitory deregulation of blood volume. The instrumental diagnosis can be easily accomplished by the tilt-table test, with continuous monitoring of blood pressure and cardiac parameters. It is a non-invasive technique and needs minimal collaboration from the patient. In our experience, when reviewing 327 patients, aged over 40 years and examined because of clinical suspicion of OH, the prevalence thereof was 51% whereas if focused in subjects older than 70, OH was proven in 90% of the cases. The older the patients, the more frequently they presented general deterioration, neurological or cardiac problems as well as pharmacological side effects. Ruling out neurological or cardiac malfunction can drastically improve the prognosis with possible reversibility of symptoms. Some nonpharmacological and pharmacological approaches to improve management of OH and life quality are described for guidance.

  11. Orthostatic Hypotension: Mechanisms, Causes, Management

    PubMed Central

    Tomalia, Victoria A.

    2015-01-01

    Orthostatic hypotension (OH) occurs when mechanisms for the regulation of orthostatic BP control fails. Such regulation depends on the baroreflexes, normal blood volume, and defenses against excessive venous pooling. OH is common in the elderly and is associated with an increase in mortality rate. There are many causes of OH. Aging coupled with diseases such as diabetes and Parkinson's disease results in a prevalence of 10-30% in the elderly. These conditions cause baroreflex failure with resulting combination of OH, supine hypertension, and loss of diurnal variation of BP. The treatment of OH is imperfect since it is impossible to normalize standing BP without generating excessive supine hypertension. The practical goal is to improve standing BP so as to minimize symptoms and to improve standing time in order to be able to undertake orthostatic activities of daily living, without excessive supine hypertension. It is possible to achieve these goals with a combination of fludrocortisone, a pressor agent (midodrine or droxidopa), supplemented with procedures to improve orthostatic defenses during periods of increased orthostatic stress. Such procedures include water bolus treatment and physical countermaneuvers. We provide a pragmatic guide on patient education and the patient-orientated approach to the moment to moment management of OH. PMID:26174784

  12. Retrospective study to characterize post-obstructive diuresis in cats with urethral obstruction.

    PubMed

    Francis, Brenda J; Wells, Raegan J; Rao, Sangeeta; Hackett, Timothy B

    2010-08-01

    Urethral obstruction is a common medical emergency in cats. Frequency of post-obstruction diuresis in cats following resolution of urethral obstruction is unknown. The objective of this study was to document frequency and associated clinical features of post-obstruction diuresis in cats. The records of 32 cats undergoing 33 admissions to the Colorado State University Veterinary Hospital for urethral obstruction were reviewed. Signalment, admission blood values, fluid therapy, and urine output were recorded. Diuresis was defined as urine output greater than 2ml/kg/h. Post-obstructive diuresis occurred in 46% (13/28) of cats within the first 6h of treatment. Occurrence of post-obstructive diuresis was statistically more likely in cats with venous pH<7.35 on admission. Urine production following resolution of urethral obstruction should be monitored so that fluid therapy can be adjusted to the individual patient, as many cats will have a higher fluid requirement secondary to post-obstruction diuresis.

  13. [Renal urodilatin secretion is associated with diuresis and natriuresis after spontaneous, supraventricular tachycardia].

    PubMed

    Kentsch, M; Kuhrmann, T; Drummer, C; Rodemerk, U; Gerzer, R; Müller-Esch, G

    1998-02-01

    Patients with paroxysmal supraventricular tachycardia (SVT) may have a polyuria after termination of tachycardia. There is increasing evidence that the renal peptide urodilatin (ANP (95-126))--and not plasma ANP (ANP (99-126))--is the member of the natriuretic peptide family mediating natriuresis and diuresis in man. In patients with SVT we, therefore, analyzed the relationship between diuresis, natriuresis, plasma ANP, urinary urodilatin excretion and renal excretion of cyclic GMP, the second messenger in the ANP system. During and after clinical presentation with spontaneously occurring SVT, two patients with AV-nodal and one patient with atrioventricular reentry tachycardia (heart rate 160 to 200 bpm) were studied. Urinary urodilatin excretion was correlated to diuresis (r = 0.73) and natriuresis (r = 0.93); similarly urinary cyclic GMP excretion was related to diuresis (r = 0.80) and natriuresis (r = 0.87; p < 0.001, respectively). In contrast, there was no significant correlation between plasma ANP concentrations and diuresis (r = 0.28, n.s.) or natriuresis (r = 0.11, n.s.). As an explorative analysis, stepwise multiple linear regression identified urinary urodilatin as the most important contributor to diuresis and natriuresis after SVT. These data on polyuria after spontaneous SVT further support the view that in man urodilatin is the member of the natriuretic peptide family participating in kidney physiology.

  14. A dynamic paracellular pathway serves diuresis in mosquito Malpighian tubules.

    PubMed

    Beyenbach, Klaus W

    2012-07-01

    Female mosquitoes gorge on vertebrate blood, a rich nutrient source for developing eggs, but gorging meals increase the risk of predation. Mosquitoes are quick to reduce the flight payload with a potent diuresis. Diuretic peptides of the insect kinin family induce a tenfold reduction in the paracellular resistance of Malpighian tubules and increase the paracellular permeation of Cl(-), the counterion of the transepithelial secretion of Na(+) and K(+). As a result, the transepithelial secretion of NaCl and KCl and water increases. Insect kinins signal the opening of the paracellular pathway via G protein-coupled receptors and the elevation of intracellular [Ca(2+)], which leads to the reorganization of the cytoskeleton associated with the septate junction (SJ). The reorganization may affect the septate junctional proteins that control the barrier and permselectivity properties of the paracellular pathway. The proteins involved in the embryonic formation of the SJ and in epithelial polarization are largely known for ectodermal epithelia, but the proteins that form and mediate the dynamic functions of the SJ in Malpighian tubules remain to be determined.

  15. Hemodilution, vasopressin suppression, and diuresis during water immersion in man

    NASA Technical Reports Server (NTRS)

    Greenleaf, J. E.; Keil, L. C.; Shvartz, E.

    1981-01-01

    The possible role of hemodilution in the early stages of water immersion in the suppression of antidiuretic hormone (vasopressin) and subsequent diuresis in man is investigated. Parameters characterizing hemodilution as well as water balance and intercompartmental fluid levels were measured before, during and after the immersion of ten subjects in a semireclining position in tap water up to their necks at 34.6 C for 8 hr. Results indicate that hemodilution and the suppression of vasopressin and plasma renin activity were present by the second hour of immersion, with the early hemodilution due to a slight increase in plasma volume with no change in plasma sodium or osmotic contents, even though urine volume and osmotic excretion rates increased significantly. Hyponatremia, hyposmotemia and plasma renin activity suppression are observed to continue to the end of immersion, resulting in final decreases of 15.6% in plasma volume, 18.8% in extracellular volume, 19.6% in interstitial volume and 10.7% in red cell volume. Findings suggest the transfer of hypotonic fluid into the vascular system, which contributes to vasopressin suppression observed during immersion.

  16. Hemodilution, vasopressin suppression, and diuresis during water immersion in man

    NASA Technical Reports Server (NTRS)

    Greenleaf, J. E.; Keil, L. C.; Shvartz, E.

    1981-01-01

    The possible role of hemodilution in the early stages of water immersion in the suppression of antidiuretic hormone (vasopressin) and subsequent diuresis in man is investigated. Parameters characterizing hemodilution as well as water balance and intercompartmental fluid levels were measured before, during and after the immersion of ten subjects in a semireclining position in tap water up to their necks at 34.6 C for 8 hr. Results indicate that hemodilution and the suppression of vasopressin and plasma renin activity were present by the second hour of immersion, with the early hemodilution due to a slight increase in plasma volume with no change in plasma sodium or osmotic contents, even though urine volume and osmotic excretion rates increased significantly. Hyponatremia, hyposmotemia and plasma renin activity suppression are observed to continue to the end of immersion, resulting in final decreases of 15.6% in plasma volume, 18.8% in extracellular volume, 19.6% in interstitial volume and 10.7% in red cell volume. Findings suggest the transfer of hypotonic fluid into the vascular system, which contributes to vasopressin suppression observed during immersion.

  17. Stretch Marks

    MedlinePlus

    ... like during puberty), that person may get fine lines on the body called stretch marks. Stretch marks happen when the skin is pulled by rapid growth or stretching. Although the skin is usually fairly elastic, when it's overstretched, the normal production of collagen (the major protein that makes up ...

  18. Evaluation of intradialytic hypotension using impedance cardiography.

    PubMed

    Bayya, Abed; Rubinger, Dvora; Linton, David Michael; Sviri, Sigal

    2011-09-01

    Hypotension during hemodialysis is frequent in patients with cardiovascular disease who have a limited physiological compensatory response. Recent advances in technology allow non-invasive monitoring of cardiac output and derived hemodynamic parameters. This prospective study evaluated episodes of intradialytic hypotension using clinical data and continuous non-invasive hemodynamic monitoring by impedance cardiography. Forty-eight chronic hemodialysis patients, with prevalence for intradialytic hypotensive episodes, underwent evaluation with non-invasive impedance cardiography (Physioflow) before, during and after a regular dialysis session. During continuous non-invasive cardiac monitoring, a fall of systolic arterial blood pressure of 20% or more at least once during hemodialysis was detected in 18 patients (37.5%)--thereafter identified as the "Unstable" group. In 30 patients--thereafter called the "Stable" group, the blood pressure did not change significantly. During hypotension, a decrease in cardiac output was found in 11 of the 18 unstable patients, and a significant fall in peripheral resistance in the remaining 7. End-diastolic filling ratio was significantly lower in the unstable group. The most significant predictors associated with intradialytic hypotension were the presence of ischemic heart disease (P = 0.05), and medication with beta blockers (P = 0.037) and calcium channel blockers (P = 0.018). Hemodynamic changes in dialysis patients with hypotensive episodes included decreased cardiac output or decreased peripheral resistance. A lower end-diastolic filling ratio may be regarded as a marker for reduced preload in these patients. Non-invasive impedance cardiography may be used to evaluate risk factors for hypotension in dialysis patients.

  19. Saccharin increases perception of bladder filling in a forced diuresis experiment.

    PubMed

    Bakali, Evangelia; Hong, Jennifer; Gillespie, James; Tincello, Douglas

    2017-06-01

    To study bladder sensation during a forced diuresis protocol and to assess differences in sensation perceived by different ethnic groups and after drinking artificially sweetened water. Female Caucasian and south Indian Asian volunteers performed the diuresis protocol drinking water, or water sweetened with saccharin (5 mg/kg body weight). Participants recorded filling sensation every 5 min while drinking 250-350 mL/15 min. They were asked to record the strongest sensation before voiding as maximum sensation, before voiding. The void was measured and sensation immediately recorded as minimum. The process was repeated. Voided volume and time required to achieve maximum sensation during cycle 2 were compared by water and sweetener, ethnic group, and age. Twenty Asian and 20 Caucasian volunteers participated. No differences in maximum voided volume or diuresis rate was seen by ethnicity. Median diuresis with sweetener was 16.7 mL/min (8.6-35) compared to 13.2 (7.1-25) with water (P = 0.008), a difference accounted for by 16 women with >5 mL/min difference in diuresis rate. These were excluded to leave 24 women with similar diuresis rates with both sweetener and water (14.8 mL/min (8.6-28.0) and 13.2 mL/min (7.1-25.0). In these women, time to achieve maximum sensation was lower with sweetener than water: 37.5 min (20-85) versus 50.0 min (20-80), P = 0.002, with no difference in voided volume. Water sweetened with saccharin produced an increased diuresis rate in some women. After controlling for this, time to recording maximum sensation was decreased with sweetened water, suggesting saccharin has an effect upon perceived sensation. © 2016 Wiley Periodicals, Inc.

  20. Hyperprolactinemia due to spontaneous intracranial hypotension.

    PubMed

    Schievink, Wouter I; Nuño, Miriam; Rozen, Todd D; Maya, M Marcel; Mamelak, Adam N; Carmichael, John; Bonert, Vivien S

    2015-05-01

    OBJECT Spontaneous intracranial hypotension is an increasingly recognized cause of headaches. Pituitary enlargement and brain sagging are common findings on MRI in patients with this disorder. The authors therefore investigated pituitary function in patients with spontaneous intracranial hypotension. METHODS Pituitary hormones were measured in a group of 42 consecutive patients with spontaneous intracranial hypotension. For patients with hyperprolactinemia, prolactin levels also were measured following treatment. Magnetic resonance imaging was performed prior to and following treatment. RESULTS The study group consisted of 27 women and 15 men with a mean age at onset of symptoms of 52.2 ± 10.7 years (mean ± SD; range 17-72 years). Hyperprolactinemia was detected in 10 patients (24%), ranging from 16 ng/ml to 96.6 ng/ml in men (normal range 3-14.7 ng/ml) and from 31.3 ng/ml to 102.5 ng/ml in women (normal range 3.8-23.2 ng/ml). In a multivariate analysis, only brain sagging on MRI was associated with hyperprolactinemia. Brain sagging was present in 60% of patients with hyperprolactinemia and in 19% of patients with normal prolactin levels (p = 0.02). Following successful treatment of the spontaneous intracranial hypotension, hyperprolactinemia resolved, along with normalization of brain MRI findings in all 10 patients. CONCLUSIONS Spontaneous intracranial hypotension is a previously undescribed cause of hyperprolactinemia. Brain sagging causing distortion of the pituitary stalk (stalk effect) may be responsible for the hyperprolactinemia.

  1. Prediction of intradialytic hypotension using photoplethysmography.

    PubMed

    Solem, Kristian; Olde, Bo; Sörnmo, Leif

    2010-07-01

    Intradialytic hypotension is the most common acute complication during conventional hemodialysis treatment. Prediction of such events is highly desirable in clinical routine for prevention. This paper presents a novel prediction method of acute symptomatic hypotension in which the photoplethysmographic signal is analyzed with respect to changes in amplitude, reflecting vasoconstriction, and cardiac output. The method is based on a statistical model in which the noise is assumed to have Laplacian amplitude distribution. The performance is evaluated on 11 hypotension-prone patients who underwent hemodialysis treatment, resulting in seven events with acute symptomatic hypotension and 17 without. The photoplethysmographic signal was continuously acquired during treatment as was information on blood pressure and oxygen saturation. Using leave-one-out cross validation, the proposed method predicted six out of seven hypotensive events, while producing 1 false prediction out of 17 possible. The performance was achieved when the prediction threshold was chosen to be in the range 57%-65% of the photoplethysmographic envelope at treatment onset.

  2. Marking Time

    ERIC Educational Resources Information Center

    Foster, Colin

    2011-01-01

    Teachers say that they would gladly teach a day in the classroom if at the end of the day they could leave and have no marking. There is a common staffroom perception that mathematics teachers have it easy when it comes to marking. In arts subjects, setting an essay can be a fairly straightforward matter--a one-line question may suffice--but…

  3. Marking Time

    ERIC Educational Resources Information Center

    Foster, Colin

    2011-01-01

    Teachers say that they would gladly teach a day in the classroom if at the end of the day they could leave and have no marking. There is a common staffroom perception that mathematics teachers have it easy when it comes to marking. In arts subjects, setting an essay can be a fairly straightforward matter--a one-line question may suffice--but…

  4. Effect of interactions between nitric oxide and angiotensin II on pressure diuresis and natriuresis.

    PubMed

    Madrid, M I; García-Salom, M; Tornel, J; De Gasparo, M; Fenoy, F J

    1997-11-01

    The present study examined the effect of an angiotensin II AT1 or AT2 receptor antagonist on the impairment of the pressure diuresis and natriuresis response produced by nitric oxide (NO) synthesis blockade. N omega-nitro-L-arginine methyl ester (L-NAME, 37 nmol.kg-1.min-1) lowered renal blood flow and reduced the slopes of the pressure diuresis and natriuresis responses by 44 and 40%, respectively. Blockade of AT1 receptors with valsartan increased slightly sodium and water excretion at low renal perfusion pressure (RPP). Blockade of AT2 receptors with PD-123319 had no effect on renal function. The administration of valsartan or PD-123319 to rats given L-NAME had no effect on the renal vasoconstriction induced by NO synthesis blockade. In addition, in rats given L-NAME, valsartan elevated baseline excretory values at all RPP studied, but it had no effect on the sensitivity of the pressure diuresis and natriuresis response. However, the administration of PD-123319 to L-NAME-pretreated rats shifted the slopes of the pressure diuresis and natriuresis responses toward control values, indicating that the impairment produced by NO synthesis blockade on pressure diuresis is dependent on the activation of AT2 angiotensin receptors.

  5. [Hypotension and bradycardia before spinal anesthesia].

    PubMed

    Shiraishi Zapata, Carlos Javier

    I report a case of hypotension and bradycardia before spinal anesthesia in a pregnant woman with mild to moderate hypertension treated with nifedipine and methyldopa, scheduled for an elective cesarean delivery. She had the history of neurally-mediated syncopes. Two main factors (increased vagal tone and adverse effects of antihypertensive drugs) could explain the hypotension and bradycardia before spinal anesthesia. Monitoring allowed recognizing the problem and corrected it. Thus, it was avoided a disaster in anesthesia, as hemodynamic changes after spinal anesthesia, they would have joined to previous hypotension and bradycardia, which would have caused even a cardiac arrest. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

  6. Genetics and molecular biology of hypotension

    NASA Technical Reports Server (NTRS)

    Robertson, D.

    1994-01-01

    Major strides in the molecular biology of essential hypertension are currently underway. This has tended to obscure the fact that a number of inherited disorders associated with low blood pressure exist and that these diseases may have milder and underrecognized phenotypes that contribute importantly to blood pressure variation in the general population. This review highlights some of the gene products that, if abnormal, could cause hypotension in some individuals. Diseases due to abnormalities in the catecholamine enzymes are discussed in detail. It is likely that genetic abnormalities with hypotensive phenotypes will be as interesting and diverse as those that give rise to hypertensive disorders.

  7. Genetics and molecular biology of hypotension

    NASA Technical Reports Server (NTRS)

    Robertson, D.

    1994-01-01

    Major strides in the molecular biology of essential hypertension are currently underway. This has tended to obscure the fact that a number of inherited disorders associated with low blood pressure exist and that these diseases may have milder and underrecognized phenotypes that contribute importantly to blood pressure variation in the general population. This review highlights some of the gene products that, if abnormal, could cause hypotension in some individuals. Diseases due to abnormalities in the catecholamine enzymes are discussed in detail. It is likely that genetic abnormalities with hypotensive phenotypes will be as interesting and diverse as those that give rise to hypertensive disorders.

  8. Interactions between nitric oxide and renal nerves on pressure-diuresis and natriuresis.

    PubMed

    Madrid, M I; Salom, M G; Tornel, J; López, E; Fenoy, F J

    1998-09-01

    The present study examined the effect of renal denervation on the impairment of the pressure-diuresis response produced by nitric oxide synthesis blockade. The experiments were performed in Inactin-anesthetized Munich-Wistar rats. The animals with innervated kidneys had lower baseline values of renal blood flow, GFR, sodium excretion (UNaV), and urine flow (V) than rats with denervated kidneys. Also, renal denervation shifted pressure-diuresis and natriuresis toward lower pressures. A low dose of N(omega)-nitro-L-arginine methyl esther (NAME, 3.7 nmol/kg per min) reduced UNaV and the fractional excretion of sodium (FENa) and blunted pressure-natriuresis only in rats with innervated kidneys, whereas it had no effects in rats with denervated kidneys. A medium dose of NAME (37 nmol/kg per min) lowered FENa only in rats with innervated kidneys. The administration of NAME (37 nmol/kg per min) blunted pressure-diuresis and natriuresis in kidneys with or without the renal nerves, but the effect was more pronounced in rats with innervated kidneys. A high dose of NAME (3.7 micromol + 185 nmol/kg per min) increased UNaV and FENa only in rats with innervated kidneys, whereas it reduced GFR, V, UnaV, and FENa in rats with denervated kidneys. However, pressure-natriuresis and diuresis were blunted by this high dose of NAME independently of the presence or absence of renal nerves. These results demonstrate that renal nerves potentiate the renal effects of low doses of NAME on renal function and pressure-diuresis and natriuresis. However, high doses of NAME abolish pressure-diuresis independently of renal nerves, and the natriuretic effect of NAME in innervated kidneys may be attributed to reflex inhibition of sympathetic tone due to the rise in arterial pressure.

  9. Orthostatic hypotension associated with dorsal medullary cavernous angioma.

    PubMed

    Idiaquez, J; Araya, P; Benarroch, E

    2009-01-01

    Orthostatic hypotension (OH) is a rare manifestation of medulla oblongata lesions that may be because of interruption of descending sympathoexcitatory axons. To illustrate the location of a medullary lesion that produced OH following resection in relationship to the location of putative sympathoexcitatory pathways. A case with dorsal medullary cavernous angioma presenting with OH is described. The possible localization of lesion was compared with distribution of tyrosine hydroxylase (TH)-immunoreactive axons in a comparable section of the medulla of a control brain. The patient had marked OH after partial removal of the cavernous angioma. Biopsy confirmed the diagnosis. The magnetic resonance imaging location of the lesion overlapped that of TH-immunoreactive axons of the medullary transtegmental tract. A restricted lesion of medullary lesion interrupting the catecholaminergic transtegmental tract arising from the sympathoexcitatory C1 neurons of the rostral ventrolateral medulla could result in severe OH.

  10. [MRI evaluation of cervicothoracic CSF hypotension].

    PubMed

    Maraval, A; Brugieres, P; Combes, C; Thomas, P; Blanc, R; Gaston, A

    2006-06-01

    We propose studying signs of cervicothoracic CSF hypotension by MRI. Axial T1-weighted GRE sequence with and without saturation bands positioned above and below the selected image plane, MR venography and MR Angiography with contrast administration are helpful to confirm the venous nature of the epidural thickening and to make the differential diagnosis with infectious or neoplastic epiduritis.

  11. Uneasy marks.

    PubMed

    Rublee, D

    1998-05-05

    Germany earned a reputation as a European nirvana, marked by a booming job market and generous health and social programs. Now, thanks to the high costs of rebuilding the former East Germany and other factors, national health programs face cutbacks. But just about everyone has a stake in guarding the status quo.

  12. Does training-induced orthostatic hypotension result from reduced carotid baroreflex responsiveness?

    NASA Technical Reports Server (NTRS)

    Pawelczyk, James A.; Raven, Peter B.

    1994-01-01

    As manned space travel has steadily increased in duration and sophistication, the answer to a simple, relevant question remains elusive. Does endurance exercise training - high intensity rhythmic activity, performed regularly for extended periods of time - alter the disposition to, or severity of, postflight orthostatic hypotension? Research results continue to provide different views; however, data are difficult to compare because of the following factors that vary between investigations: the type of orthostatic stress imposed (+Gz, lower body negative pressure (LBNP), head-up tilt); pretest perturbations used (exercise, heat exposure, head-down tilting, bed rest, water immersion, hypohydration, pharmacologically-induced diuresis); the length of the training program used in longitudinal investigations (days versus weeks versus months); the criteria used to define fitness; and the criteria used to define orthostatic tolerance. Generally, research results indicate that individuals engaged in aerobic exercise activities for a period of years have been reported to have reduced orthostatic tolerance compared to untrained control subjects, while the results of shorter term longitudinal studies remain equivocal. Such conclusions suggest that chronic athletic training programs reduce orthostatic tolerance, whereas relatively brief (days to weeks) training programs do not affect orthostatic tolerance to any significant degree (increase or decrease). A primary objective was established to identify the alterations in blood pressure control that contribute to training-induced orthostatic hypotension (TIOH). Although any aspect of blood pressure regulation is suspect, current research has been focused on the baroreceptor system. Reductions in carotid baroreflex responsiveness have been documented in exercise-trained rabbits, reportedly due to an inhibitory influence from cardiac afferent, presumably vagal, nerve fibers that is abolished with intrapericardiac denervation. The

  13. Hypotension and hypovolemia during hemodialysis: is the usual suspect innocent?

    PubMed

    Berger, David; Takala, Jukka

    2016-06-09

    Hypotension during intermittent hemodialysis is common, and has been attributed to acute volume shifts, shifts in osmolarity, electrolyte imbalance, temperature changes, altered vasoregulation, and sheer hypovolemia. Although hypovolemia may intuitively seem a likely cause for hypotension in intensive care patients, its role in the pathogenesis of intradialytic hypotension may be overestimated.

  14. Hypotension and environmental noise: a replication study.

    PubMed

    Lercher, Peter; Widmann, Ulrich; Thudium, Jürg

    2014-08-26

    Up to now, traffic noise effect studies focused on hypertension as health outcome. Hypotension has not been considered as a potential health outcome although in experiments some people also responded to noise with decreases of blood pressure. Currently, the characteristics of these persons are not known and whether this down regulation of blood pressure is an experimental artifact, selection, or can also be observed in population studies is unanswered. In a cross-sectional replication study, we randomly sampled participants (age 20-75, N = 807) from circular areas (radius = 500 m) around 31 noise measurement sites from four noise exposure strata (35-44, 45-54, 55-64, >64 Leq, dBA). Repeated blood pressure measurements were available for a smaller sample (N = 570). Standardized information on socio-demographics, housing, life style and health was obtained by door to door visits including anthropometric measurements. Noise and air pollution exposure was assigned by GIS based on both calculation and measurements. Reported hypotension or hypotension medication past year was the main outcome studied. Exposure-effect relationships were modeled with multiple non-linear logistic regression techniques using separate noise estimations for total, highway and rail exposure. Reported hypotension was significantly associated with rail and total noise exposure and strongly modified by weather sensitivity. Reported hypotension medication showed associations of similar size with rail and total noise exposure without effect modification by weather sensitivity. The size of the associations in the smaller sample with BMI as additional covariate was similar. Other important cofactors (sex, age, BMI, health) and moderators (weather sensitivity, adjacent main roads and associated annoyance) need to be considered as indispensible part of the observed relationship. This study confirms a potential new noise effect pathway and discusses potential patho-physiological routes of actions.

  15. Hypotension and Environmental Noise: A Replication Study

    PubMed Central

    Lercher, Peter; Widmann, Ulrich; Thudium, Jürg

    2014-01-01

    Up to now, traffic noise effect studies focused on hypertension as health outcome. Hypotension has not been considered as a potential health outcome although in experiments some people also responded to noise with decreases of blood pressure. Currently, the characteristics of these persons are not known and whether this down regulation of blood pressure is an experimental artifact, selection, or can also be observed in population studies is unanswered. In a cross-sectional replication study, we randomly sampled participants (age 20–75, N = 807) from circular areas (radius = 500 m) around 31 noise measurement sites from four noise exposure strata (35–44, 45–54, 55–64, >64 Leq, dBA). Repeated blood pressure measurements were available for a smaller sample (N = 570). Standardized information on socio-demographics, housing, life style and health was obtained by door to door visits including anthropometric measurements. Noise and air pollution exposure was assigned by GIS based on both calculation and measurements. Reported hypotension or hypotension medication past year was the main outcome studied. Exposure-effect relationships were modeled with multiple non-linear logistic regression techniques using separate noise estimations for total, highway and rail exposure. Reported hypotension was significantly associated with rail and total noise exposure and strongly modified by weather sensitivity. Reported hypotension medication showed associations of similar size with rail and total noise exposure without effect modification by weather sensitivity. The size of the associations in the smaller sample with BMI as additional covariate was similar. Other important cofactors (sex, age, BMI, health) and moderators (weather sensitivity, adjacent main roads and associated annoyance) need to be considered as indispensible part of the observed relationship. This study confirms a potential new noise effect pathway and discusses potential patho-physiological routes of actions

  16. Pharmacokinetic-Pharmacodynamic Analysis of Cisplatin with Hydration and Mannitol Diuresis: The Contribution of Urine Cisplatin Concentration to Nephrotoxicity.

    PubMed

    Fukushima, Keizo; Okada, Akira; Oe, Hiroyuki; Hirasaki, Mika; Hamori, Mami; Nishimura, Asako; Shibata, Nobuhito; Sugioka, Nobuyuki

    2017-09-14

    Forced diuresis, high-volume hydration with diuresis, is widely used as a prophylactic treatment against cisplatin nephrotoxicity. However, the details of the underlying mechanisms and the optimal protocol of forced diuresis remain unclear. The present study investigated the alterations in pharmacokinetics and pharmacodynamics (nephrotoxicity) of cisplatin with forced diuresis treatment. Cisplatin (5 mg/kg) was intravenously injected to rats (5 rats/group, except for control group in pharmacodynamic study, n = 13) treated with or without forced diuresis 2-h pre- and post-hydration with 10% mannitol at different infusion rates (0.3, 1.0, and 3.0 mL/h). The unbound cisplatin concentrations in plasma and urine, and the platinum amount in the kidney were monitored in the pharmacokinetic studies. The plasma creatinine concentration was evaluated as an index of nephrotoxicity in the pharmacodynamic studies. Forced diuresis treatment did not significantly alter the plasma cisplatin pharmacokinetics but dramatically decreased the urine concentration of unbound cisplatin and its accumulation into the kidneys in a dose-dependent manner, and correspondingly, nephrotoxicity was dose-dependently attenuated by forced diuresis. The pharmacokinetic-pharmacodynamic analysis suggested that the urine cisplatin concentration has a comparable impact on the cisplatin-induced nephrotoxicity to that in plasma, probably owing to the reabsorption of cisplatin from urine, which can be attenuated by forced diuresis. These results indicated that the nephroprotective effect of forced diuresis is a pharmacokinetic-based drug-drug interaction possibly due to the inhibition of cisplatin reabsorption from urine. Monitoring of urine cisplatin concentration may lead to the optimization of a forced diuresis protocol with mannitol.

  17. Perfusion index derived from a pulse oximeter can predict the incidence of hypotension during spinal anaesthesia for Caesarean delivery.

    PubMed

    Toyama, S; Kakumoto, M; Morioka, M; Matsuoka, K; Omatsu, H; Tagaito, Y; Numai, T; Shimoyama, M

    2013-08-01

    Hypotension during spinal anaesthesia for Caesarean delivery is a result of decreased vascular resistance due to sympathetic blockade and decreased cardiac output due to blood pooling in blocked areas of the body. Change in baseline peripheral vascular tone due to pregnancy may affect the degree of such hypotension. The perfusion index (PI) derived from a pulse oximeter has been used for assessing peripheral perfusion dynamics due to changes in peripheral vascular tone. The aim of this study was to examine whether baseline PI could predict the incidence of spinal anaesthesia-induced hypotension during Caesarean delivery. Parturients undergoing elective Caesarean delivery under spinal anaesthesia with hyperbaric bupivacaine 10 mg and fentanyl 20 μg were enrolled in this prospective study. The correlation between baseline PI and the degree of hypotension during spinal anaesthesia and also the predictability of spinal anaesthesia-induced hypotension during Caesarean delivery by PI were investigated. Baseline PI correlated with the degree of decreases in systolic and mean arterial pressure (r=0.664, P<0.0001 and r=0.491, P=0.0029, respectively). The cut-off PI value of 3.5 identified parturients at risk for spinal anaesthesia-induced hypotension with a sensitivity of 81% and a specificity of 86% (P<0.001). The change of PI in parturients with baseline PI ≤ 3.5 was not significant during the observational period, while PI in parturients with baseline PI>3.5 demonstrated marked decreases after spinal injection. We demonstrated that higher baseline PI was associated with profound hypotension and that baseline PI could predict the incidence of spinal anaesthesia-induced hypotension during Caesarean delivery.

  18. Importance of Residual Water Permeability on the Excretion of Water during Water Diuresis in Rats

    PubMed Central

    Cheema-Dhadli, Surinder; Chong, Chee Keong; Kim, Namhee; Kamel, Kamel S

    2010-01-01

    When the concentration of sodium (Na+) in arterial plasma (PNa) declines sufficiently to inhibit the release of vasopressin, water will be excreted promptly when the vast majority of aquaporin 2 water channels (AQP2) have been removed from luminal membranes of late distal nephron segments. In this setting, the volume of filtrate delivered distally sets the upper limit on the magnitude of the water diuresis. Since there is an unknown volume of water reabsorbed in the late distal nephron, our objective was to provide a quantitative assessment of this parameter. Accordingly, rats were given a large oral water load, while minimizing non-osmotic stimuli for the release of vasopressin. The composition of plasma and urine were measured. The renal papilla was excised during the water diuresis to assess the osmotic driving force for water reabsorption in the inner medullary collecting duct. During water diuresis, the concentration of creatinine in the urine was 13-fold higher than in plasma, which implies that ~8% of filtered water was excreted. The papillary interstitial osmolality was 600 mOsm/L > the urine osmolality. Since 17% of filtered water is delivered to the earliest distal convoluted tubule micropuncture site, we conclude that half of the water delivered to the late distal nephron is reabsorbed downstream during water diuresis. The enormous osmotic driving force for the reabsorption of water in the inner medullary collecting duct may play a role in this reabsorption of water. Possible clinical implications are illustrated in the discussion of a case example. PMID:21468191

  19. Bradykinin may be involved in neuropeptide Y-induced diuresis, natriuresis, and calciuresis.

    PubMed

    Bischoff, A; Rascher, W; Michel, M C

    1998-10-01

    Neuropeptide Y (NPY) can cause diuresis, natriuresis, and calciuresis in rats independently of the pressure-natriuresis mechanism (A. Bischoff and M. C. Michel. Pflügers Arch. 435: 443-453, 1998). Because this is seen in systemic but not intrarenal NPY infusion, we have investigated the possible mediator of tubular NPY effects in anesthetized rats. In the present study, infusion of NPY (2 micrograms . kg-1 . min-1) enhanced renovascular resistance by approximately 8 mmHg . ml-1 . min and enhanced urine and sodium excretion by approximately 450 microliter/15 min and approximately 60-85 micromol/15 min, respectively. Acute renal denervation did not alter renovascular or tubular NPY effects, indicating that a neuronally released mediator is not involved. Treatment with the angiotensin II-receptor antagonist losartan prevented the decline of the renovascular response with time but did not modify tubular NPY effects. The bradykinin B2-receptor antagonist icatibant accelerated the decline of the renovascular NPY effects with time; concomitantly, it attenuated NPY-induced diuresis and natriuresis and abolished NPY-induced calciuresis. The converting-enzyme inhibitor ramiprilat prevented the decline of the renovascular response with time; concomitantly, it magnified the NPY-induced diuresis, natriuresis, and calciuresis. We conclude that bradykinin may be involved in NPY-induced diuresis, natriuresis, and, in particular, calciuresis.

  20. Cardiac morphology and function in patients with and without residual diuresis on hemodialysis.

    PubMed

    Araujo, Salustiano; Lemes, Helton P; Cunha, Danny A; Queiroz, Vinicius S; Nascimento, Daniela D; Ferreira Filho, Sebastião Rodrigues

    2011-03-01

    In patients with chronic renal failure on hemodialysis, left ventricular hypertrophy is related to the increase in total peripheral vascular resistance and volume overload. The presence of residual diuresis enables greater control of the volemia of these. We evaluated the morpho-functional changes of the left ventricle in patients with chronic kidney disease on hemodyalisis treatment with and without residual diuresis. A total of 31 non diabetic patients were studied and they were divided into two groups: with residual diuresis (RD+) (n = 17) and without residual diuresis (RD-) (n = 14). In both groups, RD+ vs. RD-, using data from a Doppler echocardiogram differences were found, respectively, in the cardiac index (3.9 ± 0.2 vs. 3.0 ± 0.2 L/min/m²; p = 0.0056), systolic index (54 ± 2.9 vs. 45 ± 3.3 mL/b/m²; p = 0.04), end diastolic volume (141 ± 6.7 vs. 112 ± 7.6 mL; p = 0.008), end diastolic diameter (52 ± 0.7 vs. 48 ± 1.1 mm; p = 0.0072) and total peripheral resistance index (1121 ± 56 vs. 1529 ± 111 dyne.sec.cm-5; p = 0.001). RD+ had lower relative wall thickness than RD- (0.38 ± 0.01 vs. 0.45 ± 0.01; p = 0.0008). The ejection fraction and the left ventricular mass index were similar in both groups. The urinary 24-hour volume correlated with the relative wall thickness (r = -0.42; p = 0.0186) and with peripheral resistance index (r = -0.48; p = 0.0059). In conclusion, there were distinct ventricular geometric patterns and different functional performances between RD+ and RD- groups. The presence of residual diuresis can be responsible by these modifications in systolic function.

  1. Caffeine-induced diuresis and natriuresis is independent of renal tubular NHE3.

    PubMed

    Fenton, Robert A; Poulsen, Søren B; de la Mora Chavez, Samantha; Soleimani, Manoocher; Busslinger, Meinrad; Dominguez Rieg, Jessica A; Rieg, Timo

    2015-06-15

    Caffeine is one of the most widely consumed behavioral substances. We have previously shown that caffeine- and theophylline-induced inhibition of renal reabsorption causes diuresis and natriuresis, an effect that requires functional adenosine A1 receptors. In this study, we tested the hypothesis that blocking the Gi protein-coupled adenosine A1 receptor via the nonselective adenosine receptor antagonist caffeine changes Na(+)/H(+) exchanger isoform 3 (NHE3) localization and phosphorylation, resulting in diuresis and natriuresis. We generated tubulus-specific NHE3 knockout mice (Pax8-Cre), where NHE3 abundance in the S1, S2, and S3 segments of the proximal tubule was completely absent or severely reduced (>85%) in the thick ascending limb. Consumption of fluid and food, as well as glomerular filtration rate, were comparable in control or tubulus-specific NHE3 knockout mice under basal conditions, while urinary pH was significantly more alkaline without evidence for metabolic acidosis. Caffeine self-administration increased total fluid and food intake comparably between genotypes, without significant differences in consumption of caffeinated solution. Acute caffeine application via oral gavage elicited a diuresis and natriuresis that was comparable between control and tubulus-specific NHE3 knockout mice. The diuretic and natriuretic response was independent of changes in total NHE3 expression, phosphorylation of serine-552 and serine-605, or apical plasma membrane NHE3 localization. Although caffeine had no clear effect on localization of the basolateral Na(+)/bicarbonate cotransporter NBCe1, pretreatment with DIDS inhibited caffeine-induced diuresis and natriuresis. In summary, NHE3 is not required for caffeine-induced diuresis and natriuresis.

  2. Impact of water-induced diuresis on excretion profiles of ethanol, urinary creatinine, and urinary osmolality.

    PubMed

    Bendtsen, P; Jones, A W

    1999-01-01

    This article reports the impact of diuresis on urinary excretion of ethanol in seven healthy volunteers who drank 1000 mL of export beer (44 g ethanol) in 30 min and, 120 min later, ingested 500 or 1000 mL of water within 5 min. Urine was voided before drinking started and every 30-60 min for 360 min after the start of drinking. The concentration of ethanol in urine (UAC) was determined by headspace gas chromatography, the creatinine content was determined by Jaffe's method, and osmolality was measured by freezing point depression. Maximum diuresis coincided with the peak UAC and was reached 60-90 min after the end of drinking. The urinary creatinine and osmolality dropped appreciably after drinking beer, and the lowest values coincided with peak diuresis. Creatinine was < 0.2 g/L in 22% of urine specimens, and osmolality was < 200 mOsm/kg in 31% of specimens. Production of urine decreased as UAC entered the postabsorptive phase but increased again after the subjects drank water 120 min after alcohol consumption. The amount of ethanol recovered in urine was 681 mg (standard deviation [SD] 203 mg) corresponding to 1.5% (SD 0.46%) of the dose administered. The concentrations of ethanol in successive voids during the postabsorptive phase were not influenced after subjects drank 500 or 1000 mL of water although diuresis increased and urinary creatinine and osmolality decreased. Measuring UAC provides a reliable way to monitor recent drinking, and unlike the analysis of illicit drugs in urine, the concentrations of ethanol are not influenced by diuresis.

  3. Osmotic diuresis due to urea as the cause of hypernatraemia in critically ill patients.

    PubMed

    Lindner, Gregor; Schwarz, Christoph; Funk, Georg-Christian

    2012-03-01

    Hypernatraemia is common in critically ill patients and has been shown to be an independent predictor of mortality. Osmotic urea diuresis can cause hypernatraemia due to significant water losses but is often not diagnosed. Free water clearance (FWC) and electrolyte free water clearance (EFWC) were proposed to quantify renal water handling. We aimed to (i) identify patients with hypernatraemia due to osmotic urea diuresis and (ii) investigate whether FWC and EFWC are helpful in identifying renal loss of free water. In this retrospective study, we screened a registry for patients, who experienced intensive care unit (ICU)-acquired hypernatraemia. Among them, patients with hypernatraemia due to osmotic urea diuresis were detected by a case-by-case review. Total fluid and electrolyte balances together with FWC and EFWC were calculated for days of rising serum sodium and stable serum sodium. We identified seven patients (10% of patients with ICU-acquired hypernatraemia) with osmotic diuresis due to urea. All patients were intubated during development of hypernatraemia and received enteral nutrition. The median highest serum sodium level of 153 mmol (Q1: 151-Q3: 155 mmol/L) was reached after a 5-day period of rise in serum sodium. During this period, FWC was -904 mL/day (Q1: -1574-Q3: -572), indicating renal water retention, while EFWC was 1419 mL/day (Q1: 1052-Q3: 1923), showing renal water loss. While FWC did not differ between time of stable serum sodium and development of hypernatraemia, EFWC was significantly higher during rise in serum sodium. Osmotic urea diuresis is a common cause of hypernatraemia in the ICU. EFWC was useful in the differential diagnosis of polyuria during rising serum sodium levels, while FWC was misleading.

  4. Caffeine-induced diuresis and natriuresis is independent of renal tubular NHE3

    PubMed Central

    Fenton, Robert A.; Poulsen, Søren B.; de la Mora Chavez, Samantha; Soleimani, Manoocher; Busslinger, Meinrad; Rieg, Timo

    2015-01-01

    Caffeine is one of the most widely consumed behavioral substances. We have previously shown that caffeine- and theophylline-induced inhibition of renal reabsorption causes diuresis and natriuresis, an effect that requires functional adenosine A1 receptors. In this study, we tested the hypothesis that blocking the Gi protein-coupled adenosine A1 receptor via the nonselective adenosine receptor antagonist caffeine changes Na+/H+ exchanger isoform 3 (NHE3) localization and phosphorylation, resulting in diuresis and natriuresis. We generated tubulus-specific NHE3 knockout mice (Pax8-Cre), where NHE3 abundance in the S1, S2, and S3 segments of the proximal tubule was completely absent or severely reduced (>85%) in the thick ascending limb. Consumption of fluid and food, as well as glomerular filtration rate, were comparable in control or tubulus-specific NHE3 knockout mice under basal conditions, while urinary pH was significantly more alkaline without evidence for metabolic acidosis. Caffeine self-administration increased total fluid and food intake comparably between genotypes, without significant differences in consumption of caffeinated solution. Acute caffeine application via oral gavage elicited a diuresis and natriuresis that was comparable between control and tubulus-specific NHE3 knockout mice. The diuretic and natriuretic response was independent of changes in total NHE3 expression, phosphorylation of serine-552 and serine-605, or apical plasma membrane NHE3 localization. Although caffeine had no clear effect on localization of the basolateral Na+/bicarbonate cotransporter NBCe1, pretreatment with DIDS inhibited caffeine-induced diuresis and natriuresis. In summary, NHE3 is not required for caffeine-induced diuresis and natriuresis. PMID:25925253

  5. Severe bradycardia and prolonged hypotension in ciguatera.

    PubMed

    Chan, Thomas Yan Keung

    2013-06-01

    Ciguatera results when ciguatoxin-contaminated coral reef fish from tropical or subtropical waters are consumed. The clinical features that present in affected persons are mainly gastrointestinal, neurological, general, and much less commonly, cardiovascular. We report the case of a 50-year-old man who developed the characteristic combination of acute gastrointestinal and neurological symptoms after the consumption of an unidentified coral reef fish head. In addition to those symptoms, he developed dizziness, severe bradycardia (46 bpm) and prolonged hypotension, which required the administration of intravenous atropine and over three days of intravenous fluid replacement with dopamine infusion. Patients with ciguatera can develop severe bradycardia and prolonged hypotension. Physicians should recognise the possible cardiovascular complications of ciguatera and promptly initiate treatment with intravenous atropine, intravenous fluid replacement and inotropic therapy if such complications are observed.

  6. Vertigo and nystagmus in orthostatic hypotension.

    PubMed

    Choi, J-H; Seo, J-D; Kim, M-J; Choi, B-Y; Choi, Y R; Cho, B M; Kim, J S; Choi, K-D

    2015-04-01

    Generalized cerebral ischaemia from cardiovascular dysfunction usually leads to presyncopal dizziness, but several studies reported a higher frequency of rotatory vertigo in cardiovascular patients. Whether generalized cerebral ischaemia due to cardiovascular disorders may produce objective vestibular dysfunction was investigated. Thirty-three patients with orthostatic dizziness/vertigo due to profound orthostatic hypotension and 30 controls were recruited. All participants underwent recording of eye movements during two orthostatic challenging tests: the Schellong and the squatting-standing tests. Most patients had neuroimaging, and patients with abnormal eye movements were subjected to follow-up evaluations. Symptoms associated with orthostatic dizziness/vertigo included blurred vision, fainting and tinnitus. Ten (30%) of 33 patients developed rotatory vertigo and nystagmus during the Schellong (n = 5) or squatting-standing test (n = 5). Four of them showed pure downbeat nystagmus whilst five had downbeat and horizontal nystagmus with or without torsional component. Patients with orthostatic nystagmus had shorter duration of orthostatic intolerance than those without nystagmus (1.0 ± 1.6 vs. 11.0 ± 9.7 months, P < 0.001). In two patients, orthostatic nystagmus disappeared during follow-up despite the persistence of profound orthostatic hypotension. Generalized cerebral ischaemia caused by orthostatic hypotension induces rotatory vertigo due to objective vestibular dysfunction. The presence of orthostatic vertigo and nystagmus has an association with the duration of orthostatic intolerance. © 2014 EAN.

  7. Adaptation of Baroreflexes and Orthostatic Hypotension

    NASA Technical Reports Server (NTRS)

    Convertino, Victor A.

    1993-01-01

    The footward shift of blood volume and compensatory autonomic reflex responses initiated during the assumption of the upright posture in terrestrial gravity is a common feature in humans. When regular exposure to upright posture is removed, the headward redistribution of blood induces numerous physiological adaptations which compromise this normal response and the development of low blood pressure upon standing (orthostatic hypotension) can ensue. Such microgravity conditions can be produced by prolonged exposure to spaceflight or prolonged bed rest. Since the reduction of blood and plasma volume during exposure to microgravity has been associated with orthostatic instability following spaceflight and bed rest, it has been a reasonable assumption that hypovolemia may be a primary contributing factor to the development of orthostatic hypotension. This view was supported by the observation that the attempt to restore vascular volume in astronauts by drinking saline solutions just prior to re-entry had proven effective in reducing orthostatic instability after spaceflights of short duration. However, as the duration of spaceflight lengthens, orthostatic instability persists despite fluid loading procedures, suggesting that mechanisms other than hypovolemia may contribute to orthostatic hypotension following prolonged exposure to microgravity conditions. Recent evidence has been generated from spaceflight and groundbase experiments that supports the notion that changes in autonomic baroreflexes that control cardiac and vascular responses during orthostatic challenges may be affected by longer periods of microgravity exposure and can contribute to postflight orthostatic instability.

  8. Effect of sertraline hydrochloride on dialysis hypotension.

    PubMed

    Dheenan, S; Venkatesan, J; Grubb, B P; Henrich, W L

    1998-04-01

    Hemodialysis hypotension (HH) is a very common disorder and has a multifactorial etiology. Autonomic dysfunction occurs in up to 50% of patients with end-stage renal disease (ESRD) and plays a key role in HH in some patients. Sertraline hydrochloride, a central nervous system serotonin reuptake inhibitor, has been shown to be an effective treatment of hypotension caused by autonomic dysfunction in disorders such as neurocardiogenic syncope and idiopathic orthostatic hypotension. This study sought to determine whether sertraline was effective in ameliorating HH. A retrospective chart analysis was performed that included nine consecutive patients (aged > or = 54 years, time on hemodialysis > or = 2.2 years) placed on sertraline (50 to 100 mg/d) for depression who also had HH (defined as prehemodialysis systolic blood pressure [SBP] < or = 100 mm Hg, > or = 40 mm Hg decrease in SBP during hemodialysis, SBP <90 mm Hg, any diastolic blood pressure <40 mm Hg, or a decrease in blood pressure-causing symptoms) before treatment with sertraline. The data from a 6-week pre-sertraline period were compared with the data from a 6-week sertraline period (defined as 6 weeks after drug begun). Blood pressure medications were unchanged during the trial period of sertraline. However, nadir mean arterial pressure recorded during a given dialysis session in the pre-sertraline period (55+/-4 mm Hg) was significantly lower than that recorded in the sertraline period (68+/-5 mm Hg; P < 0.05). In addition, the number of hypotensive episodes (same definition as HH) per dialysis session during the sertraline period was significantly lower than that during the pre-sertraline period (mean, 0.6+/-0.2 episodes per session v 1.4+/-0.3 episodes per session; P < 0.005). The number of therapeutic interventions required for hypotension during the sertraline period was also significantly less than that during the pre-sertraline period (mean, 1.7+/-0.8 interventions v 11.0+/-3.0 interventions; P < 0

  9. Genetic AVP deficiency abolishes cold-induced diuresis but does not attenuate cold-induced hypertension.

    PubMed

    Sun, Zhongjie

    2006-06-01

    Chronic cold exposure causes hypertension and diuresis. The aim of this study was to determine whether vasopressin (AVP) plays a role in cold-induced hypertension and diuresis. Two groups of Long-Evans (LE) and two groups of homozygous AVP-deficient Brattleboro (VD) rats were used. Blood pressure (BP) was not different among the four groups during a 2-wk control period at room temperature (25 degrees C, warm). After the control period, one LE group and one VD group were exposed to cold (5 degrees C); the remaining groups were kept at room temperature. BP and body weight were measured weekly during exposure to cold. Food intake, water intake, urine output, and urine osmolality were measured during weeks 1, 3, and 5 of cold exposure. At the end of week 5, all animals were killed and blood was collected for measurement of plasma AVP. Kidneys were removed for measurement of renal medulla V2 receptor mRNA and aquaporin-2 (AQP-2) protein expression. BP of LE and VD rats increased significantly by week 2 of cold exposure and reached a high level by week 5. BP elevations developed at approximately the same rate and to the same degree in LE and VD rats. AVP deficiency significantly increased urine output and solute-free water clearance and decreased urine osmolality. Chronic cold exposure increased urine output and solute-free water clearance and decreased urine osmolality in LE rats, indicating that cold exposure caused diuresis in LE rats. Cold exposure failed to affect these parameters in VD rats, suggesting that the AVP system is responsible for cold-induced diuresis. Cold exposure did not alter plasma AVP in LE rats. Renal medulla V2 receptor mRNA and AQP-2 protein expression levels were decreased significantly in the cold-exposed LE rats, suggesting that cold exposure inhibited renal V2 receptors and AVP-inducible AQP-2 water channels. We conclude that 1) AVP may not be involved in the pathogenesis of cold-induced hypertension, 2) the AVP system plays a critical role

  10. Medial prefrontal cortex acetylcholine injection-induced hypotension: the role of hindlimb vasodilation

    NASA Technical Reports Server (NTRS)

    Crippa, G. E.; Lewis, S. J.; Johnson, A. K.; Correa, F. M.

    2000-01-01

    The injection of acetylcholine (ACh) into the cingulate region of the medial prefrontal cortex (MPFC) causes a marked fall in arterial blood pressure which is not accompanied by changes in heart rate. The purpose of the present study was to investigate the hemodynamic basis for this stimulus-induced hypotension in Sprague-Dawley rats. The study was designed to determine whether a change in the vascular resistance of hindlimb, renal or mesenteric vascular beds contributes to the fall in arterial pressure in response to ACh injection into the cingulate cortex. Miniature pulsed-Doppler flow probes were used to measure changes in regional blood flow and vascular resistance. The results indicated that the hypotensive response was largely due to a consistent and marked vasodilation in the hindlimb vascular bed. On this basis, an additional experiment was then undertaken to determine the mechanisms that contribute to hindlimb vasodilation. The effect of interrupting the autonomic innervation of one leg on the hindlimb vasodilator response was tested. Unilateral transection of the lumbar sympathetic chain attenuated the cingulate ACh-induced vasodilation in the ipsilateral, but not in the contralateral hindlimb. These results suggest that the hypotensive response to cingulate cortex-ACh injection is caused by skeletal muscle vasodilation mediated by a sympathetic chain-related vasodilator system.

  11. Medial prefrontal cortex acetylcholine injection-induced hypotension: the role of hindlimb vasodilation

    NASA Technical Reports Server (NTRS)

    Crippa, G. E.; Lewis, S. J.; Johnson, A. K.; Correa, F. M.

    2000-01-01

    The injection of acetylcholine (ACh) into the cingulate region of the medial prefrontal cortex (MPFC) causes a marked fall in arterial blood pressure which is not accompanied by changes in heart rate. The purpose of the present study was to investigate the hemodynamic basis for this stimulus-induced hypotension in Sprague-Dawley rats. The study was designed to determine whether a change in the vascular resistance of hindlimb, renal or mesenteric vascular beds contributes to the fall in arterial pressure in response to ACh injection into the cingulate cortex. Miniature pulsed-Doppler flow probes were used to measure changes in regional blood flow and vascular resistance. The results indicated that the hypotensive response was largely due to a consistent and marked vasodilation in the hindlimb vascular bed. On this basis, an additional experiment was then undertaken to determine the mechanisms that contribute to hindlimb vasodilation. The effect of interrupting the autonomic innervation of one leg on the hindlimb vasodilator response was tested. Unilateral transection of the lumbar sympathetic chain attenuated the cingulate ACh-induced vasodilation in the ipsilateral, but not in the contralateral hindlimb. These results suggest that the hypotensive response to cingulate cortex-ACh injection is caused by skeletal muscle vasodilation mediated by a sympathetic chain-related vasodilator system.

  12. Dopamine-resistant hypotension and severe retinopathy of prematurity

    PubMed Central

    Catenacci, Melissa; Miyagi, Shogo; Wickremasinghe, Andrea C.; Lucas, Sarah Scarpace; de Alba Campomanes, Alejandra G.; Good, William V.; Clyman, Ronald I.

    2013-01-01

    Objective To examine the relationship between the cause or severity of hypotension and the development of severe retinopathy of prematurity (sROP) (≥ stage 3 or stage 2 with plus disease in Zone I or II).. Study design Infants (<28 weeks’ gestation, n=242) were observed for hypotension and treated with a standardized hypotension-treatment protocol. Hypotension was classified as resulting from one of the following causes: (a) culture-positive infection and/or necrotizing enterocolitis, (b) PDA ligation, or (c) “idiopathic” (no cause identified other than prematurity), and as being either dopamine-responsive or dopamine-resistant. Cortisol levels were measured for infants with dopamine-resistant hypotension. Eye examinations were performed until the ROP resolved or the vasculature matured. Multivariable logistic regression analysis was performed to determine the relationship between the cause/severity of hypotension and sROP. Results Overall, 66% of infants developed hypotension (41% were dopamine-responsive and 25% were dopamine-resistant). sROP developed in 19% of infants. “Idiopathic” dopamine-resistant hypotension was the only cause significantly related to sROP. 66% of infants with dopamine-resistant hypotension had low serum cortisol (≤10 μg/dL). Low cortisol, in the presence of dopamine-resistant hypotension, was significantly associated with sROP and accounted for the relationship between “idiopathic” hypotension and sROP. When low cortisol was included in statistical models, other known risk factors, such as immature gestation, were no longer significantly related to sROP. Conclusion Low cortisol, in the presence of dopamine-resistant hypotension, has the greatest magnitude of association with sROP. PMID:23465406

  13. Pharmacology of Casimiroa edulis IV. Hypotensive effects of compounds isolated from methanolic extracts in rats and guinea pigs.

    PubMed

    Magos, G A; Vidrio, H; Reynolds, W F; Enríquez, R G

    1999-01-01

    Bioassay-directed fractionation of the methanolic extract of seeds of Casimiroa edulis led to the isolation of seven constituents with cardiovascular activity, namely the new compound synephrine acetonide and the known compounds N-monomethylhistamine, N,N-dimethylhistamine, proline, N-methylproline, gamma-aminobutyric acid and casimiroedine. In anesthetized rats, both histamine derivatives produced transient hypotension mediated via H1-histaminergic receptors and in the case of N,N-dimethylhistamine, via nitric oxide release. Synephrine acetonide produced transient hypertension and tachycardia, mediated via alpha- and alpha- and beta-adrenergic receptores, respectively. The chromatographic zone containing N-methyproline, proline and gamma-aminobutyric acid elicited marked and prolonged hypotension. Finally, casimiroedine did not modify the blood pressure of anesthetized rats, but lowered it persistently in anesthetized guinea pigs. It was concluded that hypotension produced by C. edulis is due to several active components. The immediate effect can be attributed to the histamine derivatives acting on H1-receptors. More prolonged hypotension would be produced by the mixture of amino acids through an unknown mechanism, as well as by casimiroedine, possibly by activation of H3-receptors. Hypotension is partially offset by synephrine acetonide through adrenergic mechanisms.

  14. Forced diuresis with the RenalGuard system: impact on contrast induced acute kidney injury.

    PubMed

    Solomon, Richard

    2014-01-01

    Kidney injury following the administration of iodinated contrast media occurs particularly in patients with reduced kidney and cardiac function and when large doses of contrast are used. There is little compelling evidence that vasodilators and anti-oxidants prevent this injury. Most prevention trials have employed intravenous volume loading as a central strategy. However, the success of this approach depends upon maintaining euvolemia while producing a vigorous diuresis. A novel strategy for maintaining euvolemia and inducing a vigorous diuresis has been developed using the RenalGuard system. In this review; the mechanism of protective action is reviewed. The trials of the RenalGuard device are reviewed and future uses of the device are discussed.

  15. Evaluation of Polyuria: The Roles of Solute Loading and Water Diuresis.

    PubMed

    Bhasin, Bhavna; Velez, Juan Carlos Q

    2016-03-01

    Polyuria, defined as daily urine output in excess of 3.0 to 3.5L/d, can occur due to solute or water diuresis. Solute-induced polyuria can be seen in hospitalized patients after a high solute load from exogenous protein administration or following relief of urinary obstruction. Similar clinical scenarios are rarely encountered in the outpatient setting. We describe a case of polyuria due to high solute ingestion and excessive water intake leading to a mixed picture of solute and water diuresis. Restriction of the daily solute load and water intake resulted in complete resolution of polyuria. Determination of the daily excreted urinary osmoles may yield important clues to the cause of polyuria and should be included in the routine workup of polyuria.

  16. PULMONARY EMBOLISM AS A CAUSE OF SYSTEMIC HYPOTENSION AND SHOCK,

    DTIC Science & Technology

    HYPOTENSION, *SHOCK(PATHOLOGY), *EMBOLISM, ETIOLOGY, ETIOLOGY, LUNG, THROMBOSIS, BLOOD COAGULATION, AUTONOMIC NERVOUS SYSTEM, SURGERY, NERVES, SYMPATHOMIMETIC AGENTS, AMINES, CARDIOVASCULAR AGENTS, ALCOHOLS, ANTISPASMODIC AGENTS.

  17. Orthostatic hypotension. Causes, evaluation, and management.

    PubMed Central

    Hollister, A S

    1992-01-01

    Chronic orthostatic hypotension is caused by a variety of disorders. Frequently patients withdraw from social interactions, are prone to adverse drug reactions and inappropriate diagnoses, and are bed-bound by the time of diagnosis. Applying basic principles of cardiovascular physiology and pharmacology usually permits these patients to lead active lives and to live longer. Much of the management is based on common sense and knowledge of the basic pathophysiology of the disorder and depends on thorough patient education and close monitoring of blood pressure in many of the activities of daily living. PMID:1475949

  18. Alanine increases blood pressure during hypotension

    NASA Technical Reports Server (NTRS)

    Conlay, L. A.; Maher, T. J.; Wurtman, R. J.

    1990-01-01

    The effect of L-alanine administration on blood pressure (BP) during haemorrhagic shock was investigated using anesthetized rats whose left carotid arteries were cannulated for BP measurement, blood removal, and drug administration. It was found that L-alanine, in doses of 10, 25, 50, 100, and 200 mg/kg, increased the systolic BP of hypotensive rats by 38 to 80 percent (while 100 mg/kg pyruvate increased BP by only 9.4 mmhg, not significantly different from saline). The results suggest that L-alanine might influence cardiovascular function.

  19. Alanine increases blood pressure during hypotension

    NASA Technical Reports Server (NTRS)

    Conlay, L. A.; Maher, T. J.; Wurtman, R. J.

    1990-01-01

    The effect of L-alanine administration on blood pressure (BP) during haemorrhagic shock was investigated using anesthetized rats whose left carotid arteries were cannulated for BP measurement, blood removal, and drug administration. It was found that L-alanine, in doses of 10, 25, 50, 100, and 200 mg/kg, increased the systolic BP of hypotensive rats by 38 to 80 percent (while 100 mg/kg pyruvate increased BP by only 9.4 mmhg, not significantly different from saline). The results suggest that L-alanine might influence cardiovascular function.

  20. Antagonistic effects of atipamezole and yohimbine on xylazine-induced diuresis in healthy dogs.

    PubMed

    Talukder, Hasanuzzaman; Hikasa, Yoshiaki; Matsuu, Aya; Kawamura, Hiroe

    2009-05-01

    The aim of this study was to investigate and compare the antagonistic effects of atipamezole and yohimbine on xylazine-induced diuresis in healthy dogs. Five healthy male beagles were assigned to each of the 8 treatment groups in a randomized design at 1-week intervals in the same dog. One group was not medicated. The dogs in the other groups received 2 mg/kg xylazine intramuscularly (IM) and a treatment of saline (control), 50, 100 or 300 microg/kg of each atipamezole or yohimbine IM 0.5 hr later. Urine and blood samples were collected 11 times over the course of 24 hr. Urine volume, pH, specific gravity and creatinine values; osmolality, electrolyte and arginine vasopressin (AVP) values in both urine and plasma; and plasma atrial natriuretic peptide (ANP) concentration were measured. Both atipamezole and yohimbine antagonized xylazine-induced diuresis. The reversal effect of yohimbine was more potent, but not dose-dependent at the tested doses, in contrast with atipamezole. Both atipamezole and yohimbine exhibited similar potency in reversing the decreases in urine specific gravity, osmolality, creatinine, sodium and chloride concentrations and the increase in the plasma potassium concentration induced by xylazine. Both also inhibited xylazine-induced diuresis without significantly altering the hormonal profile in the dogs. A higher dose of atipamezole tended to increase the plasma ANP concentration. This may not be due only to actions mediated by alpha(2)-adrenoceptors. Both drugs can be used as antagonistic agents against xylazine-induced diuresis in healthy dogs.

  1. Effect of water temperature on diuresis-natriuresis: AVP, ANP, and urodilatin during immersion in men

    NASA Technical Reports Server (NTRS)

    Nakamitsu, S.; Sagawa, S.; Miki, K.; Wada, F.; Nagaya, K.; Keil, L. C.; Drummer, C.; Gerzer, R.; Greenleaf, J. E.; Hong, S. K.

    1994-01-01

    Effects of water temperature on diuresis, natriuresis, and associated endocrine responses during head-out immersion were studied in eight men during four 5-h experimental conditions: air control at 28 C and immersion at 34.5 C (thermoneutral (Tnt)), 36 C (above Tnt (aTnt)), and 32 C (below Tnt (bTnt). Esophageal temperature decreased by approximately 0.4 C in bTnt and increased by approximately 0.5 C in aTnt. Cardiac output increased by approximately 80% in aTnt and approximately 40% in bTnt while thoracic impedance, an index of central blood pooling, decreased by 7.5 ohms in bTnt (NS vs. Tnt) and 8.8 ohms in aTnt. Total peripheral resistance decreased at all temperatures (50% in aTnt, 20% in bTnt). Urine flow and Na(+) excretion increased by sixfold in bTnt and Tnt but by only threefold in aTnt. Creatinine clearance was unchanged while osmolal clearance (but not free water clearance) increased two-fold with all immersions. Plasma atrial natriuretic peptide (ANP), urinary urodilatin, and urinary guanosine 3',5'-cyclic monophosphate increased while plasma renin activity, aldosterone, and arginine vasopressin (AVP) decreased similarly at all temperatures. bTnt did not potentiate diuresis by selective attenuation of AVP. The overall natriuretic response exhibited a higher correlation with urodilatin than with ANP. Because diuresis and natriuresis were significantly attenuated in aTnt where central blood pooling was greater, we conclude that mechanisms other than the atrial stretch receptor reflex, i.e., urodilatin and effective arterial blood volume, may play more predominant roles in the mechanism of immersion-induced diuresis and natriuresis.

  2. Effect of water temperature on diuresis-natriuresis: AVP, ANP, and urodilatin during immersion in men

    NASA Technical Reports Server (NTRS)

    Nakamitsu, S.; Sagawa, S.; Miki, K.; Wada, F.; Nagaya, K.; Keil, L. C.; Drummer, C.; Gerzer, R.; Greenleaf, J. E.; Hong, S. K.

    1994-01-01

    Effects of water temperature on diuresis, natriuresis, and associated endocrine responses during head-out immersion were studied in eight men during four 5-h experimental conditions: air control at 28 C and immersion at 34.5 C (thermoneutral (Tnt)), 36 C (above Tnt (aTnt)), and 32 C (below Tnt (bTnt). Esophageal temperature decreased by approximately 0.4 C in bTnt and increased by approximately 0.5 C in aTnt. Cardiac output increased by approximately 80% in aTnt and approximately 40% in bTnt while thoracic impedance, an index of central blood pooling, decreased by 7.5 ohms in bTnt (NS vs. Tnt) and 8.8 ohms in aTnt. Total peripheral resistance decreased at all temperatures (50% in aTnt, 20% in bTnt). Urine flow and Na(+) excretion increased by sixfold in bTnt and Tnt but by only threefold in aTnt. Creatinine clearance was unchanged while osmolal clearance (but not free water clearance) increased two-fold with all immersions. Plasma atrial natriuretic peptide (ANP), urinary urodilatin, and urinary guanosine 3',5'-cyclic monophosphate increased while plasma renin activity, aldosterone, and arginine vasopressin (AVP) decreased similarly at all temperatures. bTnt did not potentiate diuresis by selective attenuation of AVP. The overall natriuretic response exhibited a higher correlation with urodilatin than with ANP. Because diuresis and natriuresis were significantly attenuated in aTnt where central blood pooling was greater, we conclude that mechanisms other than the atrial stretch receptor reflex, i.e., urodilatin and effective arterial blood volume, may play more predominant roles in the mechanism of immersion-induced diuresis and natriuresis.

  3. Osmotic diuresis-induced hypernatremia: better explained by solute-free water clearance or electrolyte-free water clearance?

    PubMed

    Popli, Subhash; Tzamaloukas, Antonios H; Ing, Todd S

    2014-01-01

    Hypernatremia may result from inadequate water intake, excessive water loss or a combination of the two. Osmotic diuresis leads to losses of both solute and water. The relationship between solute and water losses determines the resulting changes in serum osmolality and sodium concentration. Total solute loss is routinely higher than loss of water in osmotic diuresis. Theoretically, then, decreases in serum osmolality (and serum sodium concentration) should follow. In clinical situations of osmotic diuresis, however, reduction in osmolality can take place, but not reduction in serum sodium concentration. It is of note that serum sodium concentration changes are related to urinary losses of sodium and potassium but not to the loss of total solute. In osmotic diuresis, the combined loss of sodium and potassium per liter of urine is lower than the concurrent serum sodium level. Consequently, hypernatremia can ensue. A patient who presented with osmotic diuresis and hypernatremia is described here. In this patient, we have shown that electrolyte-free water clearance is a better index of the effect of osmotic diuresis on serum sodium concentration than the classic solute-free water clearance.

  4. Thienoquinolins exert diuresis by strongly inhibiting UT-A urea transporters.

    PubMed

    Ren, Huiwen; Wang, Yanhua; Xing, Yongning; Ran, Jianhua; Liu, Ming; Lei, Tianluo; Zhou, Hong; Li, Runtao; Sands, Jeff M; Yang, Baoxue

    2014-12-15

    Urea transporters (UT) play an important role in the urine concentration mechanism by mediating intrarenal urea recycling, suggesting that UT inhibitors could have therapeutic use as a novel class of diuretic. Recently, we found a thienoquinolin UT inhibitor, PU-14, that exhibited diuretic activity. The purpose of this study was to identify more potent UT inhibitors that strongly inhibit UT-A isoforms in the inner medullary collecting duct (IMCD). Efficient thienoquinolin UT inhibitors were identified by structure-activity relationship analysis. Urea transport inhibition activity was assayed in perfused rat terminal IMCDs. Diuretic activity of the compound was determined in rats and mice using metabolic cages. The results show that the compound PU-48 exhibited potent UT-A inhibition activity. The inhibition was 69.5% with an IC50 of 0.32 μM. PU-48 significantly inhibited urea transport in perfused rat terminal IMCDs. PU-48 caused significant diuresis in UT-B null mice, which indicates that UT-A is the target of PU-48. The diuresis caused by PU-48 did not change blood Na(+), K(+), or Cl(-) levels or nonurea solute excretion in rats and mice. No toxicity was detected in cells or animals treated with PU-48. The results indicate that thienoquinolin UT inhibitors induce a diuresis by inhibiting UT-A in the IMCD. This suggests that they may have the potential to be developed as a novel class of diuretics with fewer side effects than classical diuretics.

  5. Diuresis by intravenous administration of xanthurenic acid in rats, and inhibition by probenecid.

    PubMed

    Uwai, Yuichi; Nakashima, Yuta; Honjo, Emi; Kawasaki, Tatsuya; Nabekura, Tomohiro

    2014-01-01

    The conjugates with sulfate and glucoside of xanthurenic acid, a tryptophan metabolite, were reported to show natriuresis. Sulfotransferase for xanthurenic acid works in the renal proximal tubule to produce the sulfate of xanthurenic acid as well as the liver, and we recently found that xanthurenic acid is a substrate of renal organic anion transporter OAT1. The purpose of this study was to examine relationship between the transport by OAT1 and diuresis related with xanthurenic acid. Drug transport experiment using Xenopus laevis oocytes represented that probenecid inhibited xanthurenic acid uptake by rat OAT1 (rOAT1). Although no diuresis was recognized by the intravenous injection of xanthurenic acid as a bolus in rats, the addition of its infusion exhibited natriuresis. Simultaneous administration of probenecid significantly decreased the urine volume and excreted amounts of sodium into urine. These findings showed the diuresis by the xanthurenic acid administration, and it was probenecid-sensitive. The rOAT1-mediated transport of xanthurenic acid might, at least in part, contribute to its diuretic effect.

  6. Antagonistic effects of atipamezole, yohimbine and prazosin on medetomidine-induced diuresis in healthy cats.

    PubMed

    Murahata, Yusuke; Yamamoto, Asami; Miki, Yuya; Hikasa, Yoshiaki

    2014-03-01

    This study aimed to investigate and compare the antagonistic effects of atipamezole, yohimbine and prazosin on medetomidine-induced diuresis in healthy cats. Five cats were repeatedly used in each of the 9 groups. One group was not medicated. Cats in the other groups received 40 µg/kg medetomidine intramuscularly and saline (as the control), 160 µg/kg prazosin, or 40, 160 or 480 µg/kg atipamezole or yohimbine intravenously 0.5 hr later. Volume, pH and specific gravity of urine; plasma arginine vasopressin (AVP) level; and creatinine, osmolality and electrolyte levels in both urine and plasma were measured. Both atipamezole and yohimbine, but not prazosin, antagonized medetomidine-induced diuresis. The antidiuretic effect of atipamezole was more potent than that of yohimbine, but was not dose dependent, in contrast to the effect of yohimbine at the tested doses. Both atipamezole and yohimbine reversed medetomidine-induced decreases in both urine specific gravity and osmolality and increases in plasma osmolality and free-water clearance. Antidiuresis of either atipamezole or yohimbine was not related to the area under the curve for AVP level, although the highest dose of both atipamezole and yohimbine initially and temporarily increased plasma AVP levels, suggesting that this may partly influence the antidiuretic effects of both agents. The diuretic effect of medetomidine in cats may be mediated by α2-adrenoceptors, but not α1-adrenoceptors. Atipamezole and yohimbine can be used as antagonistic agents against medetomidine-induced diuresis in healthy cats.

  7. Osmotic adaptation of renal medullary cells during transition from chronic diuresis to antidiuresis.

    PubMed

    Sone, M; Albrecht, G J; Dörge, A; Thurau, K; Beck, F X

    1993-04-01

    The cells of the renal medulla adapt osmotically to high extracellular tonicities by high concentrations of organic osmolytes. Intracellular accumulation of these substances is, however, relatively slow. The aim of the present study was to assess the effect of an abrupt rise in extracellular tonicity on intracellular osmotically active substances after prior reduction of medullary contents of organic osmolytes by chronic diuresis. Intra- and extracellular electrolyte concentrations at the papillary tip and the tissue contents of methylamines (glycerophosphorylcholine, betaine), polyols (myo-inositol, sorbitol), and several amino acids were determined in the different kidney zones by electron microprobe analysis and high-performance liquid chromatography in control animals, in rats infused for 6 days with furosemide via osmotic minipumps, and in rats given the vasopressin analogue [deamino-Cys1,D-Arg8]vasopressin (DDAVP) after the chronic furosemide treatment. Chronic diuresis greatly reduced interstitial tonicity and inner medullary contents of methylamines and polyols and moderately reduced inner medullary amino acid contents but did not significantly affect intracellular electrolyte concentrations. When the diuretic rats were infused with DDAVP for 2 h, interstitial tonicity more than doubled and intracellular K and Cl concentrations rose by approximately 60 and 160%, while inner medullary contents of methylamines, polyols, and amino acids were not changed significantly. These data demonstrate that after effective depletion of medullary organic osmolytes by long-term diuresis, the cells of the renal papilla adapt osmotically to an abrupt increase in extracellular tonicities by elevated cell electrolyte concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

  8. Thienoquinolins exert diuresis by strongly inhibiting UT-A urea transporters

    PubMed Central

    Ren, Huiwen; Wang, Yanhua; Xing, Yongning; Ran, Jianhua; Liu, Ming; Lei, Tianluo; Zhou, Hong; Li, Runtao; Sands, Jeff M.

    2014-01-01

    Urea transporters (UT) play an important role in the urine concentration mechanism by mediating intrarenal urea recycling, suggesting that UT inhibitors could have therapeutic use as a novel class of diuretic. Recently, we found a thienoquinolin UT inhibitor, PU-14, that exhibited diuretic activity. The purpose of this study was to identify more potent UT inhibitors that strongly inhibit UT-A isoforms in the inner medullary collecting duct (IMCD). Efficient thienoquinolin UT inhibitors were identified by structure-activity relationship analysis. Urea transport inhibition activity was assayed in perfused rat terminal IMCDs. Diuretic activity of the compound was determined in rats and mice using metabolic cages. The results show that the compound PU-48 exhibited potent UT-A inhibition activity. The inhibition was 69.5% with an IC50 of 0.32 μM. PU-48 significantly inhibited urea transport in perfused rat terminal IMCDs. PU-48 caused significant diuresis in UT-B null mice, which indicates that UT-A is the target of PU-48. The diuresis caused by PU-48 did not change blood Na+, K+, or Cl− levels or nonurea solute excretion in rats and mice. No toxicity was detected in cells or animals treated with PU-48. The results indicate that thienoquinolin UT inhibitors induce a diuresis by inhibiting UT-A in the IMCD. This suggests that they may have the potential to be developed as a novel class of diuretics with fewer side effects than classical diuretics. PMID:25298523

  9. [Volume therapy in hypotensive trauma patients].

    PubMed

    Pargger, H; Studer, W; Rüttimann, U

    2000-10-21

    In trauma patients it is mandatory to establish the exact reason for their hypotension. If hypovolaemia is most probably responsible for the hypotension, fluid resuscitation should be initiated. The therapy of choice is infusion of sugarless, isotonic crystalloids with a physiologic serum electrolyte composition. In patients with brain injuries a decrease in serum osmolality is not advisable and hypertonic fluids may therefore be considered. Human albumin preparations are no longer indicated, but synthetic colloids may be an adjunct to a pure crystalloid regime. Hydroxyethyl starch preparations with a molecular weight in the mean range are reasonable choices considering the individual advantages and disadvantages of the various colloids. Larger blood losses must be treated with blood components such as packed red cells, fresh frozen plasma and thrombocyte concentrates as indicated. There are no widely accepted values for laboratory or monitoring parameters in starting or stopping a given fluid therapy; these values are unquestionably influenced, among other things, by the patient history and the pattern of the injuries. Initial resuscitation (when to start, who should administer the fluid and how much) also remains a focus of heated controversy.

  10. Severe postural hypotension following home canoe construction from polyester resins.

    PubMed Central

    MacFarlane, I. A.; Wilkinson, R.; Harrington, J. M.

    1984-01-01

    On two occasions a 36-year-old man developed severe postural hypotension and neurological signs after working with a polyester resin canoe building kit in an unventilated shed. It is likely that his recurrent illness was caused by styrene intoxication. Postural hypotension secondary to styrene exposure has not previously been reported. PMID:6463006

  11. Effect of canagliflozin on blood pressure and adverse events related to osmotic diuresis and reduced intravascular volume in patients with type 2 diabetes mellitus.

    PubMed

    Weir, Matthew R; Januszewicz, Andrzej; Gilbert, Richard E; Vijapurkar, Ujjwala; Kline, Irina; Fung, Albert; Meininger, Gary

    2014-12-01

    ] and polyuria [increased urine frequency]) vs placebo (6.7%, 5.6%, and 0.8%). The incidence of intravascular volume reduction-related AEs (eg, orthostatic hypotension and postural dizziness) was low across groups (1.2%, 1.3%, and 1.1%). In summary, canagliflozin was associated with reduced BP in patients with T2DM across a range of baseline BPs, with increased incidence of AEs related to osmotic diuresis but not intravascular volume reduction.

  12. Pathophysiology of the Cardiovascular System and Neonatal Hypotension.

    PubMed

    Shead, Sandra L

    2015-01-01

    Hypotension is common in low birth weight neonates and less common in term newborns and is associated with significant morbidity and mortality. Determining an adequate blood pressure in neonates remains challenging for the neonatal nurse because of the lack of agreed-upon norms. Values for determining norms for blood pressure at varying gestational and postnatal ages are based on empirical data. Understanding cardiovascular pathophysiology, potential causes of hypotension, and assessment of adequate perfusion in the neonatal population is important and can assist the neonatal nurse in the evaluation of effective blood pressure. This article reviews cardiovascular pathophysiology as it relates to blood pressure and discusses potential causes of hypotension in the term and preterm neonate. Variation in management of hypotension across centers is discussed. Underlying causes and pathophysiology of hypotension in the neonate are described.

  13. Predictors of dexmedetomidine-associated hypotension in critically ill patients

    PubMed Central

    Gerlach, Anthony T.; Blais, Danielle M.; Jones, G. Morgan; Burcham, Pamela K.; Stawicki, Stanislaw P.; Cook, Charles H.; Murphy, Claire V.

    2016-01-01

    Background: Dexmedetomidine is commonly used for sedation in the Intensive Care Unit (ICU), and its use may be associated with hypotension. We sought to determine predictors of dexmedetomidine-associated hypotension. Methods: Retrospective, single-center study of 283 ICU patients in four adults ICUs over a 12 month period. Univariate analyses were performed to determine factors associated with dexmedetomidine-related hypotension. Risk factors significant at the 0.20 level in the univariate analysis were considered for inclusion into a step-wise multiple logistical regression model. Results: Hypotension occurred in 121 (42.8%) patients with a median mean arterial pressure (MAP) nadir of 54 mmHg. Univariate analyses showed an association between hypotension and age (P = 0.03), Acute Physiology and Chronic Health Evaluation II (APACHE II) score (P = 0.02), baseline MAP (<0.001), admission to the cardiothoracic ICU (P = 0.05), history of coronary artery disease (P = 0.02), and postcardiac surgery (P = 0.0009). Admission to the medical ICU was associated with a decrease in development in hypotension (P = 0.03). There was a trend for hypotension with weight (P = 0.09) and history of congestive heart failure (P = 0.12) Only MAP prior to initiation (odds ratio [OR] 0.97, 95% confidence interval [95% CI] 0.95–0.99; P < 0.0001), APACHE II scores (OR 1.06, 95% CI 1.01–1.12; P = 0.017), and history of coronary artery disease (OR 0.48, 95% CI 0.26–0.90, P = 0.022) were independently associated with hypotension by multivariable analysis. Conclusions: Dexmedetomidine-associated hypotension is common. Preexisting low blood pressure, history of coronary artery disease, and higher acuity were identified as independent risk factors for dexmedetomidine-associated hypotension. PMID:27722111

  14. Dynamic gadolinium-enhanced magnetic resonance urography for assessing drainage in dilated pelvicalyceal systems with moderate renal function: preliminary results and comparison with diuresis renography.

    PubMed

    Chu, W C W; Lam, W W M; Chan, K W; Yeung, C K; Lee, K H; Sihoe, J D Y

    2004-04-01

    To evaluate the use of dynamic gadolinium diethylenetriaminepenta-acetic acid (DTPA)-enhanced magnetic resonance urography (Gd-MRU) for assessing kidneys with markedly dilated pelvicalyceal systems and impaired function. Eight children (mean age 30 months, sd 25) were assessed, diagnosed as having gross unilateral hydronephrosis with a mean (sd) anteroposterior renal pelvic diameter of 36 (7) mm and reduced (30-40%) renal function. Dynamic Gd-MRU was performed after the patients were pre-loaded with intravenous fluid and diuretics, and comprised a dynamic T1-weighted sequence after Gd-DTPA (0.1 mmol/kg body weight) was administered, with a time-intensity curve of each kidney produced. Drainage was diagnosed by a clearly declining time-intensity curve and direct visualization of contrast medium within the ureter in several frames. High-grade or complete obstruction was diagnosed when drainage of contrast medium could not be detected. Gd-MRU results were compared with diuresis radionuclide (mercapto-acetyltriglycine, MAG3) renography within the same week. Unobstructive units detected by Gd-MRU were treated conservatively with a close follow-up by ultrasonography and radionuclide studies. Diuresis MAG3 renography showed drainage in three dilated units and poor washout in five; in contrast, Gd-MRU showed drainage in seven dilated systems (three showed poor washout by MAG3), and obstruction in the remaining case. The unobstructed units detected by MRU under conservative treatment thus showed no further deterioration of renal function or progressive hydronephrosis in the subsequent follow-up (mean 18 months, range 15-23). These preliminary results suggest that dynamic Gd-MRU is a useful noninvasive imaging method in distinguishing obstructive from unobstructive dilated systems, particularly in patients with hydronephrosis and reduced renal function.

  15. Effects of bradykinin B2 receptor antagonism on the hypotensive effects of ACE inhibition.

    PubMed Central

    Bouaziz, H; Joulin, Y; Safar, M; Benetos, A

    1994-01-01

    1. The aim of this study was to determine the participation of endogenous bradykinin (BK) in the antihypertensive effects of the angiotensin converting enzyme inhibitor (ACEI), perindoprilat, in the spontaneously hypertensive rat (SHR) on different salt diets. 2. Conscious SHRs receiving either a low or a high NaCl diet were used in order to evaluate the respective roles of angiotensin II suppression and bradykinin stimulation in the acute hypotensive effects of perindoprilat. Two different B2 receptor antagonists (B 4146 and Hoe 140) were used after bolus administration of 7 mg kg-1 of the ACEI, perindoprilat. In separate animals, Hoe 140 was administered before the injection of perindoprilat. In other experiments, the effects of Hoe 140 on the hypotensive effects of the calcium antagonist, nicardipine, were tested. 3. The different NaCl diets had no effect on baseline blood pressure. Hoe 140 injection before ACE inhibition did not modify blood pressure. Perindoprilat caused more marked hypotension in the low salt-fed rats than in the high salt animals (P < 0.01). Administration of Hoe 140 or B4146 after perindoprilat significantly reduced the antihypertensive effects of perindoprilat in the different groups, but this effect was more pronounced in high salt-fed rats. However, in SHRs receiving Hoe 140 before perindoprilat, the antihypertensive effect of perindoprilat was completely abolished in both high or low salt diet rats. In separate experiments we confirmed that Hoe 140 did not affect the hypotensive efficacy of the calcium antagonist, nicardipine. 4. Our study shows that inhibition of endogenous bradykinin degradation participates in the acute antihypertensive effects of perindoprilat in SHRs. The role of bradykinin is more pronounced following exposure to a high salt diet i.e., when the renin-angiotensin system is suppressed.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7858859

  16. Discovery of novel selective hypotensive vasopressin peptides that exhibit little or no functional interactions with known oxytocin/vasopressin receptors

    PubMed Central

    Chan, W Y; Wo, N C; Stoev, S; Cheng, L L; Manning, M

    1998-01-01

    Arginine-vasopressin (VP) has both vasoconstricting and vasodilating action. We report here the discovery of four novel selective hypotensive VP analogues: d(CH2)5[D-Tyr(Et)2,Arg3,Val4]AVP; d(CH2)5[D-Tyr(Et)2,Lys3,Val4]AVP and their iodinatable Tyr-NH29 analogues.Bioassays in rats for activities characteristic of neurohypophysial peptides showed that the four VP peptides possessed little or no V1a, V2 or oxytocin (OT) receptor agonistic or antagonistic activities.In anaesthetized rats, these peptides (0.05–0.10 mg kg−1 i.v.) elicited a marked fall in arterial blood pressure.Blockade of cholinoceptors, adrenoceptors and bradykinin B2 receptors, and inhibition of prostaglandin synthesis had little effect on their vasodepressor action.Classical V1a, V2 and OT receptor antagonists did not block the vasodepressor response.L-NAME, 0.2 mg kg−1 min−1, markedly suppressed the hypotensive response to ACh but not the vasodepressor response to the hypotensive VP peptides. However, the duration of the vasodepressor response was shortened. Very high doses of L-NAME attenuated both the vasodepressor response and the duration of action.These findings indicate that the vasodepressor action of these VP peptides is independent of the peripheral autonomic, bradykinin and PG systems and is not mediated by the known classical OT/VP receptors. NO does not appear to have an important role in their vasodepressor action.The discovery of these novel VP peptides could lead to the development of new tools for the investigation of the complex cardiovascular actions of VP and the introduction of a new class of hypotensive agents. The two iodinatable hypotensive VP peptides could be radiolabelled as potential markers for the localization of the receptor system involved. PMID:9831918

  17. Antagonistic effects of atipamezole, yohimbine, and prazosin on xylazine-induced diuresis in clinically normal cats.

    PubMed

    Murahata, Yusuke; Miki, Yuya; Hikasa, Yoshiaki

    2014-10-01

    This study aimed to investigate and compare the antagonistic effects of atipamezole, yohimbine, and prazosin on xylazine-induced diuresis in clinically normal cats. Five cats were repeatedly used in each of the 9 groups. One group was not medicated. Cats in the other groups received 2 mg/kg BW xylazine intramuscularly, and saline (as the control); 160 μg/kg BW prazosin; or 40, 160, or 480 μg/kg BW atipamezole or yohimbine intravenously 0.5 h later. Urine and blood samples were collected 10 times over 8 h. Urine volume, pH, and specific gravity; plasma arginine vasopressin (AVP) concentration; and creatinine, osmolality, and electrolyte values in both urine and plasma were measured. Both atipamezole and yohimbine antagonized xylazine-induced diuresis, but prazosin did not. The antidiuretic effect of atipamezole was more potent than that of yohimbine but not dose-dependent, in contrast to the effect of yohimbine at the tested doses. Both atipamezole and yohimbine reversed xylazine-induced decreases in both urine specific gravity and osmolality, and the increase in free water clearance. Glomerular filtration rate, osmolar clearance, and plasma electrolyte concentrations were not significantly altered. Antidiuresis of either atipamezole or yohimbine was not related to the area under the curve for AVP concentration, although the highest dose of both atipamezole and yohimbine increased plasma AVP concentration initially and temporarily, suggesting that this may in part influence antidiuretic effects of both agents. The diuretic effect of xylazine in cats may be mediated by α2-adrenoceptors but not α1-adrenoceptors. Atipamezole and yohimbine can be used as antagonistic agents against xylazine-induced diuresis in clinically normal cats.

  18. Function of cGMP-dependent protein kinase II in volume load-induced diuresis.

    PubMed

    Schramm, Andrea; Schinner, Elisabeth; Huettner, Johannes P; Kees, Frieder; Tauber, Philipp; Hofmann, Franz; Schlossmann, Jens

    2014-10-01

    Atrial natriuretic peptide (ANP)/cGMPs cause diuresis and natriuresis. Their downstream effectors beyond cGMP remain unclear. To elucidate a probable function of cGMP-dependent protein kinase II (cGKII), we investigated renal parameters in different conditions (basal, salt diets, starving, water load) using a genetically modified mouse model (cGKII-KO), but did not detect any striking differences between WT and cGKII-KO. Thus, cGKII is proposed to play only a marginal role in the adjustment of renal concentration ability to varying salt loads without water restriction or starving conditions. When WT mice were subjected to a volume load (performed by application of a 10-mM glucose solution (3% of BW) via feeding needle), they exhibited a potent diuresis. In contrast, urine volume was decreased significantly in cGKII-KO. We showed that AQP2 plasma membrane (PM) abundance was reduced for about 50% in WT upon volume load, therefore, this might be a main cause for the enhanced diuresis. In contrast, cGKII-KO mice almost completely failed to decrease AQP2-PM distribution. This significant difference between both genotypes is not induced by an altered p-Ser256-AQP2 phosphorylation, as phosphorylation at this site decreases similarly in WT and KO. Furthermore, sodium excretion was lowered in cGKII-KO mice during volume load. In summary, cGKII is only involved to a minor extent in the regulation of basal renal concentration ability. By contrast, cGKII-KO mice are not able to handle an acute volume load. Our results suggest that membrane insertion of AQP2 is inhibited by cGMP/cGKII.

  19. Antagonistic effects of atipamezole, yohimbine, and prazosin on xylazine-induced diuresis in clinically normal cats

    PubMed Central

    Murahata, Yusuke; Miki, Yuya; Hikasa, Yoshiaki

    2014-01-01

    This study aimed to investigate and compare the antagonistic effects of atipamezole, yohimbine, and prazosin on xylazine-induced diuresis in clinically normal cats. Five cats were repeatedly used in each of the 9 groups. One group was not medicated. Cats in the other groups received 2 mg/kg BW xylazine intramuscularly, and saline (as the control); 160 μg/kg BW prazosin; or 40, 160, or 480 μg/kg BW atipamezole or yohimbine intravenously 0.5 h later. Urine and blood samples were collected 10 times over 8 h. Urine volume, pH, and specific gravity; plasma arginine vasopressin (AVP) concentration; and creatinine, osmolality, and electrolyte values in both urine and plasma were measured. Both atipamezole and yohimbine antagonized xylazine-induced diuresis, but prazosin did not. The antidiuretic effect of atipamezole was more potent than that of yohimbine but not dose-dependent, in contrast to the effect of yohimbine at the tested doses. Both atipamezole and yohimbine reversed xylazine-induced decreases in both urine specific gravity and osmolality, and the increase in free water clearance. Glomerular filtration rate, osmolar clearance, and plasma electrolyte concentrations were not significantly altered. Antidiuresis of either atipamezole or yohimbine was not related to the area under the curve for AVP concentration, although the highest dose of both atipamezole and yohimbine increased plasma AVP concentration initially and temporarily, suggesting that this may in part influence antidiuretic effects of both agents. The diuretic effect of xylazine in cats may be mediated by α2-adrenoceptors but not α1-adrenoceptors. Atipamezole and yohimbine can be used as antagonistic agents against xylazine-induced diuresis in clinically normal cats. PMID:25356000

  20. [Drinking water and urinary stones. Which drinking water and which modalities of diuresis?].

    PubMed

    Hubert, Jacques; Hubert, Claire; Jungers, Paul; Daudon, Michel; Hartemann, Philippe

    2002-09-01

    Urologists frequently advise a high fluid intake to their patients with calcium stones, but apart from this simple advice, they often have few convincing arguments. This article describes the various types of drinking water available in France (mineral water, spring water, tap water), the legislation concerning drinking water, and the ions that must be taken into account for long-term forced diuresis. After studying their composition and adapting the dietary advice (particularly concerning dairy foods) to this ionic composition, various types of water can be advised to patients, including tap water, most types of spring water, but not all mineral waters.

  1. The role of nitric oxide in saline-induced natriuresis and diuresis in rats.

    PubMed

    Noonan, W T; Banks, R O

    1999-09-01

    This study was designed to determine to what extent nitric oxide (NO) mediates the natriuretic and diuretic responses to acute isotonic saline (0.9 gram % NaCl) volume expansion (SVE, 0.5 ml min-1 kg-1). Studies were performed on 49 pentobarbital anesthetized (65 mg/kg) female Sprague-Dawley rats with or without a NO synthase inhibitor, Nomega-nitro-L-arginine (LNA). Group 1 received saline at 27 microliter/min for 1 hr (baseline) and then SVE for 1 hr; Groups 2-4 received LNA at 10, 150, and 200 microgram kg-1 min-1, respectively, for 1 hr followed by LNA + SVE. To determine to what extent inhibition of NOS would reverse an ongoing SVE-induced natriuresis and diuresis, Group 5 was saline-volume-expanded for hours 1 and 2 whereas Group 6 was administered SVE during the first hour and then SVE + 150 microgram kg -1 min-1 LNA during the second hour. SVE caused a significant (P < 0.05) increase in the glomerular filtration rate (GFR) of Group 1 and the LNA-treated rats (Groups 2-4). This SVE-induced increase in the GFR occurred despite the fact that baseline GFR was significantly lower in the two groups of rats that were infused with the highest doses of LNA (Groups 3-4). SVE was also associated with similar increases in urine flow rate, sodium and potassium excretion, and total osmolar excretion in Groups 1-4. On the other hand, mean arterial pressure (MAP) was significantly higher in Group 2 during SVE + LNA and during the baseline as well as during the SVE periods in Groups 3-4; MAP was also significantly elevated in Group 6 during SVE + LNA. Thus, despite the fact that MAP was higher in LNA-treated rats, sodium and urine flow rates were the same as in Group 1 (i.e., there was no evidence of a pressure natriuresis or diuresis in these animals). Along these lines, there was a small but significant positive linear correlation coefficient (r = 0.41, P = 0.05) between sodium excretion values and corresponding MAP values in SVE control rats but not in Groups 3-4 during

  2. Effects of in vivo 'priming' on endotoxin-induced hypotension and tissue injury. The role of PAF and tumor necrosis factor.

    PubMed Central

    Sun, X. M.; Hsueh, W.; Torre-Amione, G.

    1990-01-01

    Exogenously administered tumor necrosis factor-alpha (TNF) and bacterial endotoxin (LPS) induce shock and tissue injury. Here, the authors studied the effect of endogenous TNF on LPS-induced hypotension and tissue injury and investigated the role of PAF in these responses. Rats were primed with intraperitoneal injection of zymosan 24 hours before, or Bacillus Calmette-Guérin (BCG) 12 to 15 days before intravenous injection of low dose (0.5 mg/kg) LPS. It was found that nonprimed animals showed mild hypotension and moderate leukopenia in response to LPS. In contrast, zymosanprimed rats developed shock and marked leukopenia, and more severe bowel injury than nonprimed rats. The authors then showed that, following LPS injection, zymosan-primed animals had higher TNF and platelet-activating factor (PAF) levels than nonprimed rats. Pretreatment of the animal with PAF antagonist, SRI 63-441, markedly ameliorated the hypotension and tissue injury. Interestingly, BCG-primed rats did not show aggravation of LPS-induced hypotension. Only TNF (but not PAF) level in these animals was increased. Thus, it appears that TNF release alone, without a sufficient increase in PAF, is incapable of causing severe hypotension. However, most of the BCG-primed animals showed tissue injury, which could be prevented by pretreatment with PAF antagonist. The authors discuss the possible mechanisms of this discrepancy between systemic and local responses in BCG-primed animals. Images Figure 3 PMID:2327475

  3. Bed Rest and Orthostatic-Hypotensive Intolerance

    NASA Technical Reports Server (NTRS)

    Schneider, Suzanne M.

    2000-01-01

    Orthostatic tolerance may be defined as the ability of humans to maintain cerebral perfusion and consciousness upon movement from a supine or sitting position to the upright posture; for example, subjects can stand suddenly or be tilted to the head-up body position. Similar but not identical physiological responses can be induced by positive G(sub Z) (head to foot) acceleration or exposure to lower body negative pressure (LBNP). The objective is to suddenly shift blood to the lower body to determine how effectively cardiovascular and neural-hormonal compensatory responses react to maintain blood pressure. In the most precise method for measuring tolerance, individuals would be stressed until they faint (syncope). However, the potential consequences and discomforts of such a test usually prohibit such a procedure so that few investigators actually induce syncope. In a more common approach, subjects are exposed to a given level of stress, for example, head-up tilt for 15 min, and any increases in heart rate or decreases in blood pressure are interpreted as indicators of progress toward syncope. Presumably, the greater the perturbation of heart rate and blood pressure, the closer to "tolerance," i.e., point of unconsciousness. Another more appropriate approach is to induce a progressively increasing hypotensive stress until pre-determined physiological responses or pre-syncopal symptoms appear. The physiological criteria may include a sudden drop in systolic blood pressure (greater than 25 mm/min), a sudden drop in heart rate (greater than 15 beats/min), or a systolic blood pressure less than 70 mmHg. The most common pre-syncopal symptoms include lightheadedness, stomach awareness or distress, feelings of warmth, tingly skin, and light to profuse sweating. Usually a combination of physiological responses and symptoms occurs such that, on different days, the tolerance time to the same orthostatic protocol is reproducible for a given individual. The assumption is that

  4. Bed Rest and Orthostatic-Hypotensive Intolerance

    NASA Technical Reports Server (NTRS)

    Schneider, Suzanne M.

    2000-01-01

    Orthostatic tolerance may be defined as the ability of humans to maintain cerebral perfusion and consciousness upon movement from a supine or sitting position to the upright posture; for example, subjects can stand suddenly or be tilted to the head-up body position. Similar but not identical physiological responses can be induced by positive G(sub Z) (head to foot) acceleration or exposure to lower body negative pressure (LBNP). The objective is to suddenly shift blood to the lower body to determine how effectively cardiovascular and neural-hormonal compensatory responses react to maintain blood pressure. In the most precise method for measuring tolerance, individuals would be stressed until they faint (syncope). However, the potential consequences and discomforts of such a test usually prohibit such a procedure so that few investigators actually induce syncope. In a more common approach, subjects are exposed to a given level of stress, for example, head-up tilt for 15 min, and any increases in heart rate or decreases in blood pressure are interpreted as indicators of progress toward syncope. Presumably, the greater the perturbation of heart rate and blood pressure, the closer to "tolerance," i.e., point of unconsciousness. Another more appropriate approach is to induce a progressively increasing hypotensive stress until pre-determined physiological responses or pre-syncopal symptoms appear. The physiological criteria may include a sudden drop in systolic blood pressure (greater than 25 mm/min), a sudden drop in heart rate (greater than 15 beats/min), or a systolic blood pressure less than 70 mmHg. The most common pre-syncopal symptoms include lightheadedness, stomach awareness or distress, feelings of warmth, tingly skin, and light to profuse sweating. Usually a combination of physiological responses and symptoms occurs such that, on different days, the tolerance time to the same orthostatic protocol is reproducible for a given individual. The assumption is that

  5. Cardiovascular effects of thyrotropin-releasing hormone in normotensive and hypotensive rats: role of rostral ventrolateral medulla.

    PubMed

    Yan, J; Chen, H; Liao, W; Lu, S

    1992-07-01

    To ascertain the central mechanism of the effects of thyrotropin-releasing hormone (TRH) on the cardiovascular system, we evaluated the effects of this neuropeptide on unit fires in the rostral ventro-lateral medulla (RVL), mean arterial pressure (MAP), and heart rate (HR) in normotensive and hypotensive rats. Intracerebroventricular injection (i.c.v.) of 10 micrograms TRH significantly increased MAP and HR in both normotensive and hypotensive rats. No similar effects were observed after saline injection. If electrolytic lesions of bilateral RVL were made, the cardiovascular effects of TRH i.c.v. failed to occur. TRH i.c.v. markedly increased the firing frequency of most units in the RVL. In particular, TRH i.c.v. increased the firing frequency of most units excitatory to a fall in MAP and decreased the firing frequency of most units inhibitory to a fall in MAP in normotensive rats. Moreover, a drop of MAP as low as 40 mmHg for 10 min resulted in an increase of the firing frequency of most units. The effect of TRH i.c.v. on the RVL units in the hypotensive rats was similar to that in the normotensive rats. Our findings suggest that TRH is able to intensify the cardiovascular activities and the RVL plays a key role in the effects of TRH on the cardiovascular system in both normotensive and hypotensive rats.

  6. Spontaneous Intracranial Hypotension Secondary to Lumbar Disc Herniation

    PubMed Central

    Kim, Kyoung-Tae

    2010-01-01

    Spontaneous intracranial hypotension is often idiopathic. We report on a patient presenting with symptomatic intracranial hypotension and pain radiating to the right leg caused by a transdural lumbar disc herniation. Magnetic resonance (MR) imaging of the brain revealed classic signs of intracranial hypotension, and an additional spinal MR confirmed a lumbar transdural herniated disc as the cause. The patient was treated with a partial hemilaminectomy and discectomy. We were able to find the source of cerebrospinal fluid leak, and packed it with epidural glue and gelfoam. Postoperatively, the patient's headache and log radiating pain resolved and there was no neurological deficit. Thus, in this case, lumbar disc herniation may have been a cause of spontaneous intracranial hypotension. PMID:20157378

  7. What Are the Signs and Symptoms of Hypotension?

    MedlinePlus

    ... away after sitting down. Severe Hypotension Linked to Shock In shock , not enough blood and oxygen flow to the ... sleepiness, and confusion. In the earliest stages of shock, it may be hard to detect any signs ...

  8. Clinical implications of delayed orthostatic hypotension

    PubMed Central

    Freeman, Roy

    2015-01-01

    Objective: To define the long-term outcome of delayed orthostatic hypotension (OH). Hypothesis: Delayed OH is an early and milder form of OH that progresses over time. Methods: We reviewed the medical records of 230 previously reported patients who completed autonomic testing at our center from January 1, 2002, through December 31, 2003. All available information on clinical diagnosis, mortality, medication use, and autonomic testing were extracted and included in the reported outcomes. Standard criteria were used to define OH and delayed OH. Results: Forty-eight individuals with delayed OH, 42 individuals with OH, and 75 controls had complete follow-up data. Fifty-four percent of individuals with delayed OH progressed to OH. Thirty-one percent of individuals with delayed OH developed an α-synucleinopathy. The 10-year mortality rate in individuals with delayed OH was 29%, in individuals with baseline OH was 64%, and in controls was 9%. The 10-year mortality of individuals who progressed to OH was 50%. Progression to OH was associated with developing an α-synucleinopathy, baseline diabetes, and abnormal baseline autonomic test results. Conclusion: Delayed OH frequently progresses to OH with a high associated mortality. PMID:26400576

  9. Spontaneous intracranial hypotension: a case study.

    PubMed

    Tyree, Tammy L; Porter, Randall

    2012-05-01

    To present an illustrative case study of a patient with spontaneous intracranial hypotension (SIH) and to increase awareness of this condition among nurse practitioners (NPs). A literature search was conducted, and deidentified patient information forms the basis of this presentation. The authors' experience and appropriate images enhance the presentation of the case study. SIH is a condition that typically occurs without a traumatic event, although it can be associated with minor trauma. It occurs when cerebrospinal fluid (CSF) leaks through a focal weakness in the dural sac or meningeal diverticula, resulting in CSF hypovolemia. Patients usually present with an orthostatic headache. The most common brain magnetic resonance imaging findings are diffuse pachymeningeal enhancement, descent of the cerebellar tonsils, and subdural fluid collections. Treatment options range from management of symptoms to surgical repair of the leak. As NPs continue to provide care in a variety of settings, including emergency departments and urgent care areas, they must be familiar with the progression of symptoms that might indicate SIH and be prepared to make appropriate referrals to prevent iatrogenic morbidity. ©2012 The Author(s) Journal compilation ©2012 American Academy of Nurse Practitioners.

  10. Update on Management of Neurogenic Orthostatic Hypotension

    PubMed Central

    Low, Phillip A.; Singer, Wolfgang

    2009-01-01

    Orthostatic hypotension (OH) is common in the elderly and in disorders like diabetes and Parkinson's disease. It is important to grade its severity and its impact on the person's quality of life. It is also possible to quantitate the severity of OH. Symptoms of OH vary with orthostatic stress, and it is important to recognize subtle symptoms such as tiredness and cognitive impairment. Standard drug treatment is efficacious in improving OH and its symptoms but will worsen supine hypertension. Pyridostigmine will modestly but significantly improve OH without worsening supine hypertension. Since orthostatic stress varies from moment to moment and drug treatment is suboptimal, it is necessary to combine drug treatment of OH with non-pharmacological approaches, such as compression of venous capacitance bed, use of physical counter-maneuvers, and intermittent water bolus treatment. Search Strategy: The manuscript is based on a focused review. To achieve this, references for this review were identified by searches of PubMed between 1995 and January 2008 using the search term “orthostatic hypotension”. Articles were also identified through searches of the authors own files. Only papers published in English were selected. The final reference list was generated on the basis of originality and relevance to the topic covered in this review, with a particular focus on data supported by clinical trials. PMID:18420158

  11. Risk Factors for Hypotension in Urgently Intubated Burn Patients

    DTIC Science & Technology

    2012-01-01

    fold increase in the odds of death. The use of propofol for the induction of anesthesia for endotracheal intubation in critically ill burned patients...did not increase the odds of hypotension or death. In burn patients requiring emergent endotracheal intubation in the BICU, the care team should...01 DEC 2012 2. REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE Risk factors for hypotension in urgently intubated burn patients 5a

  12. Orthostatic hypotension as a manifestation of vitamin B12 deficiency.

    PubMed

    Ganjehei, Leila; Massumi, Ali; Razavi, Mehdi; Wilson, James M

    2012-01-01

    A 90-year-old woman with orthostatic hypotension and near-syncope was found to have a low-normal level of vitamin B(12) and no other medical findings that could explain her orthostasis. Her symptoms responded to vitamin B(12) replacement therapy. This case shows that vitamin B(12) deficiency can induce orthostatic hypotension and syncope that are correctable by vitamin B(12) replacement.

  13. Cognitive performance in hypotensive persons with spinal cord injury

    PubMed Central

    Jegede, Adejoke B.; Rosado-Rivera, Dwindally; Bauman, William A.; Cardozo, Christopher P.; Sano, Mary; Moyer, Jeremy M.; Brooks, Monifa; Wecht, Jill Maria

    2010-01-01

    Background Due to sympathetic de-centralization, individuals with spinal cord injury (SCI), especially those with tetraplegia, often present with hypotension, worsened with upright posture. Several investigations in the non-SCI population have noted a relationship between chronic hypotension and deficits in memory, attention and processing speed and delayed reaction times. Objective To determine cognitive function in persons with SCI who were normotensive or hypotensive over a 24-h observation period while maintaining their routine activities. Methods Subjects included 20 individuals with chronic SCI (2–39 years), 13 with tetraplegia (C4–8) and 7 with paraplegia (T2–11). Individuals with hypotension were defined as having a mean 24-h systolic blood pressure (SBP) below 110 mmHg for males and 100 mmHg for females, and having spent ≥50% of the total time below these gender-specific thresholds. The cognitive battery used included assessment of memory (CVLT), attention and processing speed (Digit Span, Stroop word and color and Oral Trails A), language (COWAT) and executive function (Oral Trails B and Stroop color–word). Results Demographic parameters did not differ among the hypotensive and normotensive groups; the proportion of individuals with tetraplegia (82%) was higher in the hypotensive group. Memory was significantly impaired (P<0.05) and there was a trend toward slowed attention and processing speed (P<0.06) in the hypotensive compared to the normotensive group. Interpretation These preliminary data suggest that chronic hypotension in persons with SCI is associated with deficits in memory and possibly attention and processing speed, as previously reported in the non-SCI population. PMID:19842013

  14. Cognitive performance in hypotensive persons with spinal cord injury.

    PubMed

    Jegede, Adejoke B; Rosado-Rivera, Dwindally; Bauman, William A; Cardozo, Christopher P; Sano, Mary; Moyer, Jeremy M; Brooks, Monifa; Wecht, Jill Maria

    2010-02-01

    Due to sympathetic de-centralization, individuals with spinal cord injury (SCI), especially those with tetraplegia, often present with hypotension, worsened with upright posture. Several investigations in the non-SCI population have noted a relationship between chronic hypotension and deficits in memory, attention and processing speed and delayed reaction times. To determine cognitive function in persons with SCI who were normotensive or hypotensive over a 24-h observation period while maintaining their routine activities. Subjects included 20 individuals with chronic SCI (2-39 years), 13 with tetraplegia (C4-8) and 7 with paraplegia (T2-11). Individuals with hypotension were defined as having a mean 24-h systolic blood pressure (SBP) below 110 mmHg for males and 100 mmHg for females, and having spent >or=50% of the total time below these gender-specific thresholds. The cognitive battery used included assessment of memory (CVLT), attention and processing speed (Digit Span, Stroop word and color and Oral Trails A), language (COWAT) and executive function (Oral Trails B and Stroop color-word). Demographic parameters did not differ among the hypotensive and normotensive groups; the proportion of individuals with tetraplegia (82%) was higher in the hypotensive group. Memory was significantly impaired (P < 0.05) and there was a trend toward slowed attention and processing speed (P < 0.06) in the hypotensive compared to the normotensive group. These preliminary data suggest that chronic hypotension in persons with SCI is associated with deficits in memory and possibly attention and processing speed, as previously reported in the non-SCI population.

  15. A centrally mediated prolonged hypotension produced by oxotremorine or pilocarpine

    PubMed Central

    Dage, R.C.

    1979-01-01

    1 Oxotremorine, methyloxotremorine, pilocarpine or arecoline were given intravenously to anaesthetized cats, dogs or rats, and intraperitoneally to conscious normotensive and spontaneously hypertensive rats, pretreated with doses of methylatropine that completely blocked peripheral muscarinic receptors, to ascertain their effects on blood pressure and heart rate. 2 Oxotremorine but not methyloxotremorine produced a prolonged hypotension in cats and dogs but not in rats. Heart rate was not changed. Pilocarpine, although less potent, produced an identical effect, whereas the effect of arecoline was short by comparison. The hypotensive effect of these drugs was reversed by atropine. 3 In dogs, oxotremorine produced a prolonged hypotension with no change in heart rate or cardiac output. 4 A decrease in spontaneous sympathetic nerve activity accompanied the hypotension in cats. Both effects were reversed by atropine but could be reinvoked by large doses of oxotremorine. 5 The oxotremorine-induced hypotension in cats was not altered by decerebration but was abolished by high cervical spinal section. 6 The results indicate that the prolonged hypotension elicited by oxotremorine is mediated by an action at muscarinic receptors in the brain stem resulting in a decrease in sympathetic nerve activity and peripheral resistance but not heart rate or cardiac output. PMID:760887

  16. Venlafaxine-Induced Orthostatic Hypotension in a Geriatric Patient

    PubMed Central

    Chikkaramanjegowda, Vidyashree; de Leon, Jose

    2013-01-01

    Venlafaxine is not usually associated with risk of orthostatic hypotension. A 65-year-old US Caucasian female taking 225 mg/day of venlafaxine extended-release developed symptomatic orthostatic hypotension. The systolic and diastolic blood pressure dropped by 25 and 18 mm Hg, respectively, from supine position to standing position within 3 minutes. The patient was otherwise healthy and the orthostatic hypotension resolved with venlafaxine discontinuation. This was a probable venlafaxine adverse drug reaction according to the Naranjo scale. This case contributes to the scarce literature that indicates that clinicians need to be aware that occasionally venlafaxine can induce clinically significant orthostatic hypotension, particularly in geriatric patients. Our patient did not have orthostatic hypotension when she was taking venlafaxine at 60 years of age in higher venlafaxine doses (300 mg/day) but developed this adverse drug reaction when venlafaxine was restarted at the geriatric age. This case indicates that a history of prior tolerance to venlafaxine does not guarantee tolerance after 65 years of age. If a clinician decides to use venlafaxine in geriatric patients, the clinician should warn the patient about the risk of orthostatic hypotension and consider very slow titration and low doses. PMID:23984153

  17. Pyridostigmine treatment trial in neurogenic orthostatic hypotension.

    PubMed

    Singer, Wolfgang; Sandroni, Paola; Opfer-Gehrking, Tonette L; Suarez, Guillermo A; Klein, Caroline M; Hines, Stacy; O'Brien, Peter C; Slezak, Jeffrey; Low, Phillip A

    2006-04-01

    Midodrine hydrochloride is the only drug demonstrated in a placebo-controlled treatment trial to improve orthostatic hypotension (OH) but it significantly worsens supine hypertension. By enhancing ganglionic transmission, pyridostigmine bromide can potentially ameliorate OH without worsening supine hypertension. To evaluate the efficacy of a single 60-mg dose of pyridostigmine bromide, alone or in combination with a subthreshold (2.5 mg) or suprathreshold (5 mg) dose of midodrine hydrochloride, compared with placebo. We report a double-blind, randomized, 4-way cross-over study of pyridostigmine in the treatment of neurogenic OH. A total of 58 patients with neurogenic OH were enrolled. After 1 day of baseline measurements, patients were given 4 treatments (3 active treatments [60 mg of pyridostigmine bromide; 60 mg of pyridostigmine bromide and 2.5 mg of midodrine hydrochloride; 60 mg of pyridostigmine bromide and 5 mg of midodrine hydrochloride] and a placebo) in random order on successive days. Blood pressure (BP) and heart rate were measured, both supine and standing, immediately before treatment and hourly for 6 hours after the treatment was given. No significant differences were seen in the supine BP, either systolic (P = .36) or diastolic (P = .85). In contrast, the primary end point of the fall in standing diastolic BP was significantly reduced (P = .02) with treatment. Pairwise comparison showed significant reduction by pyridostigmine alone (BP fall of 27.6 mm Hg vs 34.0 mm Hg with placebo; P = .04) and pyridostigmine and 5 mg of midodrine hydrochloride (BP fall of 27.2 mm Hg vs 34.0 mm Hg with placebo; P = .002). Standing BP improvement significantly regressed with improvement in OH symptoms. Pyridostigmine significantly improves standing BP in patients with OH without worsening supine hypertension. The greatest effect is on diastolic BP, suggesting that the improvement is due to increased total peripheral resistance.

  18. Wave reflections, arterial stiffness, and orthostatic hypotension.

    PubMed

    Sung, Shih-Hsien; Chen, Zu-Yin; Tseng, Tzu-Wei; Lu, Dai-Yin; Yu, Wen-Chung; Cheng, Hao-Min; Chen, Chen-Huan

    2014-12-01

    The effect of wave reflections on blood pressure change associated with posture remains unclear. We therefore applied a wave separation technique to investigate the relations of the backward pressure wave amplitude with orthostatic pressure changes and orthostatic hypotension (OH). We analyzed data from 613 subjects who had participated in our hemodynamic studies. Measurements of brachial systolic (SBP) and diastolic blood pressures (DBP), carotid-femoral pulse wave velocity (cf-PWV), and backward pressure wave amplitude from a decomposed carotid pressure wave (Pb) were obtained at supine position. SBP and DBP were measured again 3 minutes after standing. OH was defined as a fall of ≥20 mm Hg in SBP and/or ≥10 mm Hg in DBP. Subjects with OH (n = 100) were characterized with significantly higher supine SBP and DBP and significantly lower standing SBP and DBP when compared with subjects without OH. Subjects with OH were also characterized with significantly higher cf-PWV and Pb. cf-PWV and Pb separately were significantly associated with the orthostatic SBP change in univariable and multivariable analyses. Also, cf-PWV and Pb separately were significant predictors of OH in univariable and multivariable analyses. cf-PWV predicted OH in the younger but less so in the older subgroup, whereas Pb demonstrated similar prediction in both subgroups. In a final multivariable model, both cf-PWV and Pb were significant independent predictors of OH. Wave reflections are an independent determinant of orthostatic SBP change and OH in both younger and older subjects. © American Journal of Hypertension, Ltd 2014. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  19. A case of isolated ACTH deficiency who developed autoimmune-mediated hypothyroidism and impaired water diuresis during glucocorticoid replacement therapy.

    PubMed

    Kageyama, Y

    2000-12-01

    A case of isolated ACTH deficiency who developed autoimmune-mediated hypothyroidism and still showed impaired water diuresis during glucocorticoid replacement therapy is reported. A 45-year-old woman was initially admitted for nausea, vomiting, and general malaise. Her serum sodium and plasma osmolality, ACTH and cortisol values were low, but her urine osmolality was high. Other pituitary hormone levels, thyroid hormone levels, and a computed tomogram of the pituitary gland were normal. The patient was treated with hydrocortisone and followed in the outpatient clinic; however, she was lost to follow up 18 months after admission. Three years later she presented with hypoglycemia and hyponatremia. Her serum or plasma ACTH, FT3, FT4, cortisol levels were low and her serum TSH level was high. Pituitary stimulation tests revealed a blunted response of ACTH to CRH and an exaggerated response of TSH to TRH. Plasma ADH was inappropriately high, and a water-loading test revealed impaired water diuresis and poor suppression of ADH. Although ADH was suppressed, impaired water diuresis was observed in the water loading test after hydrocortisone supplementation. Thyroxine supplementation completely normalized the water diuresis. Her outpatient clinic medical records revealed a gradual increase in TSH levels during follow up, indicating that she had developed hypothyroidism during glucocorticoid replacement therapy. The hyponatremia on the first admission was due to glucocorticoid deficiency, whereas the hyponatremia on the second admission was due to combined deficiencies of glucocorticoid and thyroid hormones.

  20. A pharmacokinetic/pharmacodynamic model capturing the time course of torasemide-induced diuresis in the dog.

    PubMed

    Paulin, A; Schneider, M; Dron, F; Woehrlé, F

    2016-12-01

    A pharmacokinetic/pharmacodynamic modelling approach was used to determine a dosage regimen which maximizes diuretic efficiency of torasemide in dogs. Kinetic profiles of plasma concentration, torasemide excretion rate in urine (TERU) and diuresis were investigated in 10 dogs after single oral administrations at 3 dose levels, 0.2, 0.8 and 1.6 mg/kg, and an intravenous injection of 0.2 mg/kg. Endogenous regulation was evidenced by a proteresis loop between TERU and diuresis. To describe the diuresis-time profile, TERU served as input into a turnover model with inhibition of loss of response, extended by a moderator acting on both loss and production of response. Estimated maximum inhibition of loss of response, Imax , was 0.984 showing that torasemide is an efficacious diuretic able to suppress almost total water reabsorption. A TERU50, value producing half of Imax , of 1.45 μg/kg/h was estimated from the model. Pharmacokinetic and pharmacodynamic parameters were used to simulate the torasemide dose-effect relationship after oral administration. Model predictions were in good agreement with diuresis measured in a validation study conducted in 10 dogs, which were administered oral doses of 0.15, 0.4, 0.75, 1.5 and 4.5 mg/kg for 5 days. Finally, oral dose associated with the highest daily diuretic efficiency was predicted to be 0.1 mg/kg.

  1. Induced hypotension during anesthesia with special reference to orthognathic surgery.

    PubMed Central

    Rodrigo, C.

    1995-01-01

    Since Gardner first used arteriotomy during anesthesia to improve visibility in the surgical field, various techniques and pharmacological agents have been tried for the same purpose. With reports documenting the spread of acquired immune deficiency syndrome through blood transfusions, prevention of homologous blood transfusions during surgery has also become a major concern. Induced hypotension has been used to reduce blood loss and thereby address both issues. In orthognathic surgery, induced hypotension during anesthesia has been used for similar reasons. It is recommended that hypotensive anesthesia be adjusted in relation to the patient's preoperative blood pressure rather than to a specific target pressure and be limited to that level necessary to reduce bleeding in the surgical field and in duration to that part of the surgical procedure deemed to benefit by it. A mean arterial blood pressure (MAP) 30% below a patient's usual MAP, with a minimum MAP of 50 mm Hg in ASA Class I patients and a MAP not less than 80 mm Hg in the elderly, is suggested to be clinically acceptable. Various pharmacological agents have been used for induced hypotension during orthognathic surgery. In addition, there are many drugs that have been used in other types of surgery that could be used in orthognathic surgery to induce hypotension. Recent reports using control groups do not show significant differences in morbidity and mortality attributable to induced hypotension during anesthesia. Appropriate patient evaluation and selection, proper positioning and monitoring, and adequate fluid therapy are stressed as important considerations in patients undergoing induced hypotension during orthognathic surgery. PMID:8934953

  2. Response by the corpuscles of Stannius to hypotensive stimuli in three divergent ray-finned fishes (Amia calva, Anguilla rostrata, and Catastomus commersoni): cardiovascular and morphological changes.

    PubMed

    Butler, D G; Zhang, D H; Villadiego, R; Oudit, G Y; Youson, J H; Cadinouche, M Z A

    2003-06-15

    In accordance with their vital role in cardiovascular physiology () corpuscles of Stannius (CS) from two teleosts and an holostean species showed marked and consistent degranulation and exocytotic responses to hypotensive stimuli. In eels (Anguilla rostrata LeSueur) acute blood withdrawal (hypovolemic hypotension) was followed by a prompt decrease in cardiac output (CO) and dorsal aortic pressure (P(DA)), a compensatory tachycardic response and an increase in systemic vascular resistance (R(SYS)). Isovolemic hypotension induced by papaverine i.v., led to a similar, but more prolonged, decrease in P(DA) but the heart rate (HR) continued to accelerate, thereby counterbalancing the severe and persistent decrease in R(SYS). Both hypovolemic and isovolemic hypotension were followed by a significant depletion of cytoplasmic granules from eel CS even though plasma concentrations of Ca, Mg, Na(+), and K(+) were normal. In an ancient holostean fish, the bowfin, Amia calva and a generalized teleost fish, Catastomus commersoni, the number of cytoplasmic granules decreased by 39% and 54%, respectively, 120 min after the acute withdrawal of 8 ml kg bw(-1) of blood. These findings suggest that a primary role of the CS is to release cytoplasmic granules containing renin or isorenin into the blood circulation, in response to hypotension and/or hypovolemia.

  3. Steep fall in cardiac output is main determinant of hypotension during drug-free and nitroglycerine-induced orthostatic vasovagal syncope.

    PubMed

    Verheyden, Bart; Liu, Jiexin; van Dijk, Nynke; Westerhof, Berend E; Reybrouck, Tony; Aubert, André E; Wieling, Wouter

    2008-12-01

    How much of the hypotension occurring during postural syncope is cardiac output-mediated and how much can be ascribed to a fall in systemic vascular resistance are unknown. The contribution of both determinants may be influenced by the use of vasoactive drugs. The purpose of this study was to assess the determinants of hypotension during drug-free and nitroglycerine (NTG)-induced vasovagal presyncope in routine tilt table testing. In this retrospective study, a total of 56 patients (37 female; age 36 +/- 19 years) with suspected vasovagal syncope and a positive tilt test at two clinical centers were selected. In 29 patients, presyncope was provoked by 0.4 mg sublingual NTG, administered in the 60 degrees head-up tilt position. In the other 27 patients, presyncope was provoked by passive tilt alone. Finger arterial pressure was monitored continuously, and left ventricular stroke volume was computed from pressure pulsations. After NTG administration, heart rate rose, and peak heart rate was similar in all patients. Use of NTG did not affect circulatory patterns precipitating a vasovagal response. On average in all patients, marked hypotension was mediated by an approximately 50% fall in cardiac output, whereas systemic vascular resistance was well maintained until presyncope. Hypotension during routine tilt testing is cardiac output-mediated, and the mechanism appears independent of the use of 0.4 mg sublingual NTG. The study data challenge the conventional idea of systemic vasodilation as the overriding cause of hypotension during postural syncope.

  4. Depression of fractional sodium reabsorption by the proximal tubule of the dog without sodium diuresis

    PubMed Central

    Howards, Stuart S.; Davis, Bernard B.; Knox, Franklyn G.; Wright, Fred S.; Berliner, Robert W.

    1968-01-01

    The effect of infusions of hyperoncotic solutions on fractional sodium reabsorption by the proximal tubule of the dog was studied by the recollection micropuncture method. Tubule fluid to plasma inulin concentration ratios were measured for identified proximal tubule segments before and after infusion of 25% albumin or dextran solutions. Results were compared with changes in fractional reabsorption during saline diuresis. Plasma volume increased 66% ± SE 5.8 after infusion of albumin solution and 94% ± SE 8.2 after infusion of dextran solution. Fractional sodium reabosorption by the proximal tubule was depressed after infusion of both of these hyperoncotic solutions. Nevertheless, changes in sodium excretion after infusion of albumin and dextran were small. In contrast, after infusions of isotonic sodium chloride solution, which increased plasma volume 61% ± SE 5.8, a decrease in fractional reabsorption of 50.7% ± SE 7.2 was associated with large changes in sodium excretion. PMID:5658588

  5. [Case of ischemic heart disease resulting from persistent diuresis after giant ovarian tumor resection].

    PubMed

    Sata, Naho; Satoh, Masaaki; Seo, Norimasa

    2010-02-01

    A patient with a giant ovarian tumor weighing about 7 kg was successfully removed by operation. However, her ECG demonstrated ischemic changes after the operation. We report a case of ischemic heart disease due to persistent diuresis after giant ovarian tumor resection. A 75-year-old, 56.5 kg, 143.5 cm woman was admitted to our hospital for ovarian tumor resection. The preoperative ECG showed normal sinus rhythm and no ischemic changes. Both general anesthesia and epidural anesthesia were planed. An epidural catheter was inserted at T12-L1. Anesthesia was induced with propofol 100 mg, fentanyl 100 microg and vecuronium 8 mg under 100% oxygen inhalation. General anesthesia was maintained with sevoflurane while epidural anesthesia was achieved using 0.375% ropivacaine 6 ml. During the operation, blood pressure was 90-110/70-80 mmHg, with SaO2, 100% and heart rate, 70-80 beats x min(-1). The content of tumor was suctioned for 30 minutes. Surgery was successfully finished without any other incidence. After extubation, her ECG changed to atrial fibrillation from normal sinus rhythm and showed ST-T depression. And then her systolic blood pressure became 80 mmHg or below, but we found continued diuresis at about 10 ml x kg(-1) x hr(-1) for over 2 hr. The total of 7 unit vasopressin was intermittently given for vasoconstriction and antidiuresis. Her hemodynamic was immediately restored, and ECG turned to normal ST-T. The patient had uneventful postoperative recovery.

  6. Chronic intrarenal insulin replacement reverses diabetes mellitus-induced natriuresis and diuresis.

    PubMed

    Manhiani, M Marlina; Duggan, A Daniel; Wilson, Hunter; Brands, Michael W

    2012-02-01

    We showed recently that sustained natriuresis in type 1 diabetic dogs was attributed to the decrease in insulin rather than the hyperglycemia alone. The sodium-retaining action of insulin appeared to require hyperglycemia, and it completely reversed the diabetic natriuresis and diuresis. This study tested whether the sodium-retaining effect was attributed to direct intrarenal actions of insulin. Alloxan-treated dogs (D; n=7) were maintained normoglycemic using 24-h/d IV insulin replacement. After control measurements, IV insulin was decreased to begin a 6-day diabetic period. Blood glucose increased from 84±6 mg/dL to an average of 428 mg/dL on days 5 and 6, sodium excretion increased from 74±8 to 98±7 meq/d over the 6 days, and urine volume increased from 1645±83 to 2198±170 mL/d. Dir dogs (n=7) were subjected to the same diabetic regimen, but, in addition, insulin was infused continuously into the renal artery at 0.3 mU/kg per minute during the 6-day period. This did not affect plasma insulin. Blood glucose increased from 94±10 mg/dL to an average of 380 mg/dL on days 5 and 6, but sodium excretion averaged 76±5 and 69±8 meq/d during control and diabetes mellitus, respectively. The diuresis also was prevented. Glomerular filtration rate increased only in Dir dogs, and there was no change in mean arterial pressure in either group. This intrarenal insulin infusion had no effect on sodium or volume excretion in normal dogs. Intrarenal insulin replacement in diabetic dogs caused a sustained increase in tubular reabsorption that completely reversed diabetic natriuresis. Insulin plus glucose may work to prevent salt wasting in uncontrolled type 2 diabetes mellitus.

  7. Gastrin and D1 dopamine receptor interact to induce natriuresis and diuresis.

    PubMed

    Chen, Yue; Asico, Laureano D; Zheng, Shuo; Villar, Van Anthony M; He, Duofen; Zhou, Lin; Zeng, Chunyu; Jose, Pedro A

    2013-11-01

    Oral NaCl produces a greater natriuresis and diuresis than the intravenous infusion of the same amount of NaCl. Gastrin is the major gastrointestinal hormone taken up by renal proximal tubule (RPT) cells. We hypothesized that renal gastrin and dopamine receptors interact to synergistically increase sodium excretion, an impaired interaction of which may be involved in the pathogenesis of hypertension. In Wistar-Kyoto rats, infusion of gastrin induced natriuresis and diuresis, which was abrogated in the presence of a gastrin (cholecystokinin B receptor [CCKBR]; CI-988) or a D1-like receptor antagonist (SCH23390). Similarly, the natriuretic and diuretic effects of fenoldopam, a D1-like receptor agonist, were blocked by SCH23390, as well as by CI-988. However, the natriuretic effects of gastrin and fenoldopam were not observed in spontaneously hypertensive rats. The gastrin/D1-like receptor interaction was also confirmed in RPT cells. In RPT cells from Wistar-Kyoto but not spontaneously hypertensive rats, stimulation of either D1-like receptor or gastrin receptor inhibited Na(+)-K(+)-ATPase activity, an effect that was blocked in the presence of SCH23390 or CI-988. In RPT cells from Wistar-Kyoto and spontaneously hypertensive rats, CCKBR and D1 receptor coimmunoprecipitated, which was increased after stimulation of either D1 receptor or CCKBR in RPT cells from Wistar-Kyoto rats; stimulation of one receptor increased the RPT cell membrane expression of the other receptor, effects that were not observed in spontaneously hypertensive rats. These data suggest that there is a synergism between CCKBR and D1-like receptors to increase sodium excretion. An aberrant interaction between the renal CCK BR and D1-like receptors (eg, D1 receptor) may play a role in the pathogenesis of hypertension.

  8. Chronic Intra-Renal Insulin Replacement Reverses Diabetes-Induced Natriuresis and Diuresis

    PubMed Central

    Manhiani, M. Marlina; Duggan, A. Daniel; Wilson, Hunter; Brands, Michael W.

    2012-01-01

    We recently showed that sustained natriuresis in Type I diabetic dogs was due to the decrease in insulin rather than the hyperglycemia alone. The sodium retaining action of insulin appeared to require hyperglycemia and it completely reversed the diabetic natriuresis and diuresis. This study tested whether the sodium retaining effect was due to direct intrarenal actions of insulin. Alloxan-treated dogs (D; n=7) were maintained normoglycemic using 24hr/day i.v. insulin replacement. After control measurements, i.v. insulin was decreased to begin a 6-day diabetic period. Blood glucose increased from 84±6 to an average of 428 mg/dL on days 5 and 6, sodium excretion increased from 74±8 to 98±7 mEq/day over the 6 days, and urine volume increased from 1645±83 to 2198±170 mL/day. Other dogs (DIr, n=7) were subjected to the same diabetic regimen, but in addition, insulin was infused continuously into the renal artery at 0.3 mU/kg/min during the 6-day period. This did not affect plasma insulin. Blood glucose increased from 94±10 to an average of 380 mg/dL on days 5 and 6, but sodium excretion averaged 76±5 and 69±8 mEq/day during control and diabetes, respectively. The diuresis also was prevented. GFR increased only in Dir dogs, and there was no change in MAP in either group. This intra-renal insulin infusion had no effect on sodium or volume excretion in normal dogs. Intra-renal insulin replacement in diabetic dogs caused a sustained increase in tubular reabsorption that completely reversed diabetic natriuresis. Insulin+glucose may work to prevent salt wasting in uncontrolled Type II diabetes. PMID:22215718

  9. Intradialytic hypotension and risk of cardiovascular disease.

    PubMed

    Stefánsson, Bergur V; Brunelli, Steven M; Cabrera, Claudia; Rosenbaum, David; Anum, Emmanuel; Ramakrishnan, Karthik; Jensen, Donna E; Stålhammar, Nils-Olov

    2014-12-05

    Patients undergoing hemodialysis have an elevated risk of cardiovascular disease-related morbidity and mortality compared with the general population. Intradialytic hypotension (IDH) is estimated to occur during 20%-30% of hemodialysis sessions. To date, no large studies have examined whether IDH is associated with cardiovascular outcomes. This study determined the prevalence of IDH according to interdialytic weight gain (IDWG) and studied the association between IDH and outcomes for cardiovascular events and mortality to better understand its role. This study retrospectively examined records of 39,497 hemodialysis patients during 2007 and 2008. US Renal Data System claims and dialysis provider data were used to determine outcomes. IDH was defined by current Kidney Disease Outcomes Quality Initiative guidelines (≥20 mmHg fall in systolic BP from predialysis to nadir intradialytic levels plus ≥2 responsive measures [dialysis stopped, saline administered, etc.]). IDWG was measured absolutely (in kilograms) and relatively (in percentages). IDH occurred in 31.1% of patients during the 90-day exposure assessment period. At baseline, the higher the IDWG (relative or absolute), the greater the frequency of IDH (P<0.001). For all-cause mortality, the median follow-up was 398 days (interquartile range, 231-602 days). Compared with patients without IDH, IDH was associated with all-cause mortality (7646 events; adjusted hazard ratio, 1.07 [95% confidence interval, 1.01 to 1.14]), myocardial infarction (2396 events; 1.20 [1.10 to 1.31]), hospitalization for heart failure/volume overload (8896 events; 1.13 [1.08 to 1.18]), composite hospitalization for heart failure/volume overload or cardiovascular mortality (10,805 events; 1.12 [1.08 to 1.17]), major adverse cardiac events (MACEs; myocardial infarction, stroke, cardiovascular mortality) (4994 events, 1.10 [1.03 to 1.17]), and MACEs+ (MACEs plus arrhythmia or hospitalization for heart failure/volume overload) (12

  10. Plants and hypotensive, antiatheromatous and coronarodilatating action.

    PubMed

    Petkov, V

    1979-01-01

    studies are presented for the following plants: Garlic, Geranium; Hellebore; Mistletoe; Olive; Valerian; Hawthorn; Pseucedanum arenarium; Periwinkle; Fumitory. For another 50 plants growing in Bulgaria and in other countries the author presents his and other investigators' experimental and clinical data about hypotensive, antiatheromatous and coronarodilatating action.

  11. Endothelial cell-specific knockout of connexin 43 causes hypotension and bradycardia in mice

    PubMed Central

    Liao, Y.; Day, K. H.; Damon, D. N.; Duling, B. R.

    2001-01-01

    Connexin 43 (Cx43) is a protein expressed in a variety of mammalian tissues. However, the lack of specific blockers and the absence of known genetic mutants have hampered the investigation of the function of this protein. Cx43-null mice die shortly after birth, thus preventing functional studies in vivo. Here, we report the generation and characterization of a vascular endothelial cell-specific deletion of the Cx43 gene (VEC Cx43 KO) in mice by using the loxP/Cre system. Using homologous recombination, a mouse line was created carrying loxP sites flanking exon 2 of the Cx43 gene (“floxed” mice). To produce cell specific deletion of the Cx43 gene, these mice were crossed with animals from a line carrying the Tie 2-Cre transgene. The homozygous VEC Cx43 KO mice survived to maturity. However, they were hypotensive and bradycardic when compared with heterozygous VEC Cx43 KO mice, or to the floxed Cx43 gene mice. The hypotension was associated with marked elevation of plasma nitric oxide (NO) levels as well as elevated plasma angiotensin (Ang) I and II. We hypothesize that endothelial cell Cx43 plays a key role in the formation and/or action of NO, and that the elevation of Ang II is a secondary event. The specific cellular basis for the hypotension remains to be established, but our findings support the idea that endothelial Cx43 gap junctions are involved in maintaining normal vascular function; moreover, these animals provide the opportunity to determine more clearly the role of endothelial Cx43 in vascular development and homeostasis. PMID:11481448

  12. Gastric distension attenuates the hypotensive effect of intraduodenal glucose in healthy older subjects.

    PubMed

    Gentilcore, Diana; Meyer, James H; Rayner, Christopher K; Horowitz, Michael; Jones, Karen L

    2008-08-01

    Postprandial hypotension occurs frequently, and current management is suboptimal. Recent studies suggest that the magnitude of the fall in postprandial blood pressure (BP) may be attenuated by gastric distension. The aim of this study was to determine the effect of gastric distension on the hypotensive response to intraduodenal (ID) glucose. Eight healthy subjects (5 males, 3 females, aged 65-76 years) received an ID infusion of either 1) 50 g glucose in 300 ml saline (ID glucose) over 60 min (t=0-60 min), 2) 50 g glucose in 300 ml saline over 60 min and intragastric (4) infusion of 500 ml water between t=7-10 min (IG water and ID glucose), or 3) ID saline (0.9%) infusion over 60 min and IG infusion of 500 ml water (IG water and ID saline) all followed by ID saline infusion for another 60 min (t=60-120 min) on three separate days. BP and heart rate (HR) were measured. Gastric emptying (GE) of the IG water was quantified by two-dimensional ultrasonography. Between t=0-60 min, systolic and diastolic BP was greater (P<0.05 for both) with IG water and ID saline compared with IG water and ID glucose, and less (P<0.05 for both) with ID glucose compared with IG water and ID glucose. These effects were evident at relatively low IG volumes (approximately 300 ml). GE was faster with IG water and ID saline when compared with IG water and ID glucose. We conclude that, in healthy older subjects, IG administration of water markedly attenuates the hypotensive response to ID glucose, presumably as a result of gastric distension.

  13. Risk factors for hypotension in urgently intubated burn patients.

    PubMed

    Dennis, Christopher J; Chung, Kevin K; Holland, Seth R; Yoon, Brian S; Milligan, Daun J; Nitzschke, Stephanie L; Maani, Christopher V; Hansen, Jacob J; Aden, James K; Renz, Evan M

    2012-12-01

    When urgently intubating patient in the burn intensive care unit (BICU), various induction agents, including propofol, are utilized that may induce hemodynamic instability. A retrospective review was performed of consecutive critically ill burn patients who underwent urgent endotracheal intubation in BICU. Basic burn-related demographic data, indication for intubation, and induction agents utilized were recorded. The primary outcomes of interest were clinically significant hypotension requiring immediate fluid resuscitation, initiation or escalation of vasopressors immediately after intubation. Secondary outcomes included ventilator days, stay length, and in-hospital mortality. Between January 2003 and August 2010, we identified 279 urgent intubations in 204 patients. Of these, the criteria for presumed sepsis were met in 60% (n=168) of the intubations. After intubation, 117 patients (42%) experienced clinically significant hypotension. Propofol (51%) was the most commonly utilized induction agent followed by etomidate (23%), ketamine (15%), and midazolam (11%). On multiple logistic regression, %TBSA (OR 1.016, 95% CI 1.004-1.027, p<0.001) and presumed sepsis (OR 1.852, 95% CI 1.100-3.117, p=0.02) were the only significant predictors of hypotension. None of the induction agents, including propofol, were significantly associated with hypotension in patients with or without presumed sepsis. In critically ill burn patients undergoing urgent endotracheal intubation, specific induction agents, including propofol, were not associated with clinically significant hypotension. Presumed sepsis and %TBSA were the most important risk factors. Published by Elsevier Ltd.

  14. [Prevention and treatment of hypotension during Caesarean delivery].

    PubMed

    Erler, Ines; Gogarten, Wiebke

    2007-03-01

    Regional anesthesia for Caesarean delivery is often accompanied by a reduction in maternal blood pressure. Maternal hypotension may lead to a reduction in uteroplacental blood flow with consecutive fetal acidosis. In order to avoid reductions in uteroplacental blood flow, tremendous research has been performed, showing that the avoidance of aortocaval compression, compression of the lower extremities, and prehydration with colloids are effective in reducing maternal hypotension. Further means include the recent introduction of low dose spinal anesthesia with a combination of small amounts of local anesthetics and opioids. Nevertheless, maternal hypotension is not always preventable and the use of vasopressors is still frequently required. Although ephedrine has been considered the vasopressor of choice over the last decades, current studies show that fetal acidosis is less frequently encountered with the use of phenylephrine, which should thus be considered as a first-line agent.

  15. Refractory hypotension in a patient with Wernicke's encephalopathy.

    PubMed

    Wang, Shi; Hou, Xiaojun; Ding, Suju; Guan, Yangtai; Zhen, Huimin; Tu, Laihui; Qiu, Yiqing

    2012-01-01

    A 57-year-old male patient with gastric carcinoma underwent radical distal gastrectomy type II + Braun anastomosis, and received total parenteral nutrition for 10 days after surgery, followed by small amounts of semi-liquid nutrition for 3 days and liquid nutrition for 2 days. The patient developed refractory hypotension for more than 1 week in the early course of disease, and on Day 15 after surgery presented with characteristic signs of Wernicke's encephalopathy, including diplopia and mental confusion. The hypotension did not improve despite appropriate fluid replacement soon after admission. Treatment with moderate dose of thiamine for 3 months partly relieved ophthalmoplegia and confusion, but not Korsakoff syndrome. This extraordinary presentation with refractory hypotension and the unusual course of the disease encouraged us to present this case.

  16. Midodrine as a Countermeasure for Post-Spaceflight Orthostatic Hypotension

    NASA Technical Reports Server (NTRS)

    Stenger, Michael B.; Stein, Sydney P.; Meck, Janice V.; Platts, Steven H.

    2008-01-01

    One possible mechanism for post-spaceflight orthostatic hypotension, which affects approximately 30% of astronauts after short duration shuttle missions, is inadequate norepinephrine release during upright posture. We performed a two phased study to determine the effectiveness of an alpha1-adrenergic agonist, midodrine, as a countermeasure to post-spaceflight orthostatic hypotension. The first phase of the study examined the landing day orthostatic responses of six veteran astronauts after oral midodrine (10 mg) administered on the ground within approximately two hours of wheel stop. One female crewmember exhibited orthostatic hypotension in a previous flight but not after midodrine. Five male crewmembers, who did not exhibit orthostatic hypotension during previous flights, also did not show signs of orthostatic hypotension after midodrine. Additionally, phase one showed that midodrine did not cause hypertension in these crewmembers. In the second phase of this study, midodrine is ingested inflight (near time of ignition, TIG) and orthostatic responses are determined immediately upon landing via an 80 degree head-up tilt test performed on the crew transport vehicle (CTV). Four of ten crewmembers have completed phase two of this study. Two crewmembers completed the landing day tilt tests, while two tests were ended early due to presyncopal symptoms. All subjects had decreased landing day stroke volumes and increased heart rates compared to preflight. Midodrine appears to have increased total peripheral resistance in one crewmember who was able to complete the landing day tilt test. The effectiveness of midodrine as a countermeasure to immediate post-spaceflight orthostatic hypotension has yet to be determined; interpretation is made more difficult due to low subject number and the lack of control subjects on the CTV.

  17. Orthostatic hypotension in patients, bed rest subjects, and astronauts

    NASA Technical Reports Server (NTRS)

    Lathers, C. M.; Charles, J. B.

    1994-01-01

    Orthostatic hypotension after even short space flights has affected a significant number of astronauts. Given the need for astronauts to function at a high level of efficiency during and after their return from space, the application of pharmacologic and other treatments is strongly indicated. This report addresses the clinical problem of orthostatic hypotension and its treatments to ascertain whether pharmacologic or physiologic treatment may be useful in the prevention of orthostatic hypotension associated with space flight. Treatment of orthostatic hypotension in patients now includes increasing intravascular volume with high sodium intake and mineralocorticoids, or increasing vascular resistance through the use of drugs to stimulate alpha or block beta vascular receptors. Earlier treatment used oral sympathomimetic ephedrine hydrochloride alone or with "head-up" bed rest. Then long-acting adrenocortical steroid desoxycorticosterone preparations with high-salt diets were used to expand volume. Fludrocortisone was shown to prevent the orthostatic drop in blood pressure. The combination of the sympathomimetic amine hydroxyamphetamine and a monoamine oxidase inhibitor tranylcypromine has been used, as has indomethacin alone. Davies et al. used mineralocorticoids at low doses concomitantly with alpha-agonists to increase vasoconstrictor action. Schirger et al used tranylcypromine and methylphenidate with or without a Jobst elastic leotard garment or the alpha-adrenergic agonist midodrine (which stimulates both arterial and venous systems without direct central nervous system or cardiac effects). Vernikos et al established that the combination of fludrocortisone, dextroamphetamine, and atropine exhibited a beneficial effect on orthostatic hypotension induced by 7-day 6 degrees head-down bed rest (a model used to simulate the weightlessness of space flight). Thus, there are numerous drugs that, in combination with mechanical techniques, including lower body negative

  18. Postprandial hypotension in the elderly: Findings in a Mexican population.

    PubMed

    Asensio, Enrique; Alvarez, José Benito; Lara, Susano; Alvarez de la Cadena, Jorge E; Juárez, Daniela

    2015-01-01

    Postprandial hypotension is a known cause of syncope in the elderly. Its prevalence is unknown in our country. A prospective cross-sectional study was performed to determine PPH's Prevalence in elderly adults of both an urban and a rural Community in the State of Queretaro. Blood pressure measurements included a basal pre-prandial record, minute 0 recording at the moment they finished the meal and every 10 min until a 90 min record was complete. We included a medical history, a mental state test for cognitive evaluation (Minimental) and Minnesota Quality of life score and a food macronutrient composition analysis. We included 256 subjects, 78.1 ± 8.8 years old, 195 (76.2%) female. Two-hundred and five subjects (80.1%) had Postprandial hypotension after one or both analyzed meals, with non-significant differences in the studied items. Sixty-six (26.2%) patients had "significant postprandial hypotension". Patients living in a special care facility had more postprandial hypotension than people at the family home (87-3% vs 69.8% respectively, p<0.0001). Post-prandial hypotension is a common finding in this elderly population. We did not find distinctive conditions or markers that allow identification of subjects at risk for postprandial hypotension and its complications. This should prompt for routine screenings in specialized facilities to prevent complications. Copyright © 2014 Instituto Nacional de Cardiología Ignacio Chávez. Published by Masson Doyma México S.A. All rights reserved.

  19. Orthostatic hypotension in patients, bed rest subjects, and astronauts

    NASA Technical Reports Server (NTRS)

    Lathers, C. M.; Charles, J. B.

    1994-01-01

    Orthostatic hypotension after even short space flights has affected a significant number of astronauts. Given the need for astronauts to function at a high level of efficiency during and after their return from space, the application of pharmacologic and other treatments is strongly indicated. This report addresses the clinical problem of orthostatic hypotension and its treatments to ascertain whether pharmacologic or physiologic treatment may be useful in the prevention of orthostatic hypotension associated with space flight. Treatment of orthostatic hypotension in patients now includes increasing intravascular volume with high sodium intake and mineralocorticoids, or increasing vascular resistance through the use of drugs to stimulate alpha or block beta vascular receptors. Earlier treatment used oral sympathomimetic ephedrine hydrochloride alone or with "head-up" bed rest. Then long-acting adrenocortical steroid desoxycorticosterone preparations with high-salt diets were used to expand volume. Fludrocortisone was shown to prevent the orthostatic drop in blood pressure. The combination of the sympathomimetic amine hydroxyamphetamine and a monoamine oxidase inhibitor tranylcypromine has been used, as has indomethacin alone. Davies et al. used mineralocorticoids at low doses concomitantly with alpha-agonists to increase vasoconstrictor action. Schirger et al used tranylcypromine and methylphenidate with or without a Jobst elastic leotard garment or the alpha-adrenergic agonist midodrine (which stimulates both arterial and venous systems without direct central nervous system or cardiac effects). Vernikos et al established that the combination of fludrocortisone, dextroamphetamine, and atropine exhibited a beneficial effect on orthostatic hypotension induced by 7-day 6 degrees head-down bed rest (a model used to simulate the weightlessness of space flight). Thus, there are numerous drugs that, in combination with mechanical techniques, including lower body negative

  20. Acarbose improved severe postprandial hypotension in a patient with diabetes mellitus.

    PubMed

    Sasaki, E; Goda, K; Nagata, K; Kitaoka, H; Ohsawa, N; Hanafusa, T

    2001-01-01

    Postprandial hypotension (PPH) is defined as a decrease of systolic blood pressure by more than 20 mmHg after meals. Severe PPH is a troublesome diabetic complication, which has no established means of treatment. We encountered a patient who had diabetes mellitus complicated by severe PPH and attempted to treat this problem using several medications (octreotide, midodrine hydrochloride, and acarbose). A 58-year-old male with diabetic triopathy complained of orthostatic dizziness and vertigo after meals. The blood pressure was monitored for 24 h with an ambulatory blood pressure monitor, revealing that the systolic blood pressure decreased markedly after breakfast and dinner by 45 and 50 mmHg, respectively. PPH was not improved by a subcutaneous injection of octreotide. Administration of midodrine hydrochloride reduced the frequency of hypotensive episodes from twice to once daily, but the magnitude of the postprandial fall in blood pressure was still around 30 mmHg. After the patient started to receive acarbose therapy, the postprandial fall in blood pressure was diminished to 18 mmHg and his symptoms largely disappeared. For the treatment of PPH in diabetic patients, our experience suggests that it may be appropriate to try first on alpha-glucosidase inhibitor like acarbose.

  1. Recent advances in the treatment of orthostatic hypotension

    NASA Technical Reports Server (NTRS)

    Robertson, D.; Davis, T. L.

    1995-01-01

    Orthostatic hypotension is a fall in blood pressure on standing that causes symptoms of dizziness, visual changes, and discomfort in the head and neck. The goal of treatment is the improvement of the patient's functional capacity, rather than a target blood pressure. For treatment to be successful, it must be individualized. Non-pharmalogic interventions include carefully managed exercise, scheduled activities, and monitoring of the environmental temperature. Agents such as fludrocortisone, midodrine, and epoetin alfa offer successful pharmacologic interventions. Although these measures ease the symptoms of orthostatic hypotension, current approaches neither reverse nor stabilize the disease process in autonomic disorders.

  2. Pharmacologic options available to treat symptomatic intradialytic hypotension.

    PubMed

    Perazella, M A

    2001-10-01

    Treatment of symptomatic intradialytic hypotension (IDH) is a difficult task for the practicing nephrologist. Minimizing patient factors that precipitate IDH as well as dialysis procedure-related components that lower blood pressure are the initial approaches to this problem. However, despite these maneuvers, hypotension often persists in a group of high-risk patients. Pharmacologic interventions are often used to reduce IDH. Unfortunately, many of the available therapies are marginally effective and/or poorly tolerated. A few therapies appear to be efficacious and well tolerated-carnitine, sertraline, and midodrine. This article reviews the various pharmacologic therapies used for IDH and makes recommendations for treatment of this difficult problem.

  3. Recent advances in the treatment of orthostatic hypotension

    NASA Technical Reports Server (NTRS)

    Robertson, D.; Davis, T. L.

    1995-01-01

    Orthostatic hypotension is a fall in blood pressure on standing that causes symptoms of dizziness, visual changes, and discomfort in the head and neck. The goal of treatment is the improvement of the patient's functional capacity, rather than a target blood pressure. For treatment to be successful, it must be individualized. Non-pharmalogic interventions include carefully managed exercise, scheduled activities, and monitoring of the environmental temperature. Agents such as fludrocortisone, midodrine, and epoetin alfa offer successful pharmacologic interventions. Although these measures ease the symptoms of orthostatic hypotension, current approaches neither reverse nor stabilize the disease process in autonomic disorders.

  4. Prospective association between hypotension and idiopathic chronic fatigue.

    PubMed

    Lucas, Katherine E; Rowe, Peter C; Coresh, Josef; Klag, Michael J; Meoni, Lucy A; Ford, Daniel E

    2004-04-01

    To determine whether there is an association between hypotension and incident cases of idiopathic chronic fatigue. A prospective study. Johns Hopkins Precursors Study. Medical students (n = 876) in graduating classes from 1948 to 1964. 'Easy fatigability' reported by participants at 5- or 10-year follow-up after graduation. The unadjusted risk in women was 5.0 (95% exact confidence interval = 1.4 to 17.4) and in men was 1.7 (95% exact confidence interval = 0.8, to 3.5). These preliminary findings suggest that hypotension may be a risk factor for the development of idiopathic chronic fatigue in women.

  5. A practical guide to the treatment of neurogenic orthostatic hypotension.

    PubMed

    Berger, Michael J; Kimpinski, Kurt

    2014-03-01

    Neurogenic orthostatic hypotension (NOH) is a debilitating condition associated with many central and peripheral neurological disorders. It has a complex pathophysiology and variable clinical presentation, which makes diagnosis and treatment difficult. Neurogenic orthostatic hypotension is often confused with other disorders of orthostatic intolerance, hypovolemic states and systemic conditions. Diagnosis is usually made by an autonomic specialist following characteristic responses to head-up tilt. Symptom control can be achieved through a combination of patient education, nonpharmacologic and pharmacologic therapy. The purpose of this review is to provide the clinician with a practical approach to the diagnosis and management of NOH.

  6. Marking nut anaphylaxis

    PubMed Central

    Kral, Anita Christine; Hayball, John; Smith, William B

    2016-01-01

    Marking nut Semecarpus anacardium, so-called because it contains a pigment that has been used in the past to mark fabrics, is a known cause of contact hypersensitivity. It may be ingested as an ingredient of some traditional Hindi foods. We describe the first reported case of anaphylaxis to marking nut. PMID:27489793

  7. Mastering Marking Madness

    ERIC Educational Resources Information Center

    Moore, Brooke

    2009-01-01

    Teachers are smart people, so why does marking reduce them to stressed and soulless messes? Because in their hearts they know that students do not learn from it, and that drives them nuts. Researchers like Lorna Earl and Dylan Wiliam have looked closely at marking systems and have proven what teachers already know deep down: marking student work…

  8. High blood pressure and syncope: orthostatic hypotension as a link.

    PubMed

    Rafanelli, Martina; Ungar, Andrea

    2016-06-22

    The prevalence of hypertension increases with the age. Diagnostic criteria are the same as for the young, but in older adults isolated systolic hypertension is more frequent, due to loss of vascular compliance. Blood pressure should be measured on both sides in the seated position, moreover in the supine and upright position to detect orthostatic hypotension. Ambulatory blood pressure monitoring is useful to detect white coat hypertension and masked hypertension, to tailor the treatment and search for diurnal and nocturnal blood pressure pattern abnormalities. Given that frailty can affect the relationship between blood pressure and mortality, the clinician should properly evaluate and monitor physical performance and cognitive status, throughout specific tools, as the Fried Frailty Phenotype, aiming at a systolic blood pressure target between 130 and 150 mmHg. Before starting hypotensive drugs, a careful risk and benefits' evaluation should be performed given the high risk of hypertension and hypotension consequences and the frequent coexistence of orthostatic hypotension, which predisposes to syncope and falls.

  9. Intracranial hypotension: the nonspecific nature of MRI findings.

    PubMed

    Bruera, O C; Bonamico, L; Giglio, J A; Sinay, V; Leston, J A; Figuerola, M L

    2000-01-01

    We present three patients who complained of postural headache related to different types of intracranial hypotension: spontaneous or primary, and secondary, but presenting the same findings on brain magnetic resonance imaging. Diffuse pachymeningeal gadolinium enhancement supports the belief that the enhancement is a nonspecific meningeal reaction to low pressure.

  10. Midodrine as a Countermeasure for Post-spaceflight Orthostatic Hypotension

    NASA Technical Reports Server (NTRS)

    Platts, Steven H.; Ziegler, Michael G.; Waters, Wendy W.; Meck, Janice V.

    2007-01-01

    Up to 30 % of astronauts exhibit post-spaceflight orthostatic hypotension due to inadequate norepinephrine release during upright posture following short duration spaceflight. We hypothesize that the (alpha)1-adrenergic agonist midodrine will be an effective countermeasure. This study is being conducted in 2 phases. The first phase is complete and consisted testing six short duration crew members. All of these subjects participated in preflight and postflight tilt testing on a control flight as well as on the test flights, where midodrine was administered after landing, 1 hour before testing. Hemodynamic variables were compared between the 2 flights. Midodrine improved stroke volume, cardiac output, systolic pressure and heart rate, without increasing vascular resistance. None of these subjects experienced orthostatic hypotension on landing day. Phase II is similar to phase I, except that midodrine is ingested in flight (near TIG) and the tilt test is performed immediately after landing on the CTV. One crewmember has completed phase II testing. This crewmember had no evidence of orthostatic hypotension or presyncope, four additional crewmembers have volunteered for this study. To date, midodrine has been shown to be a safe and effective countermeasure to post-spaceflight orthostatic hypotension.

  11. Central Methysergide Prevents Renal Sympathoinhibition and Bradycardia during Hypotensive Hemorrhage

    NASA Technical Reports Server (NTRS)

    Veelken, Roland; Johnson, Kim; Scrogin, Karie E.

    1998-01-01

    Central methysergide prevents renal sympathoinhibition and bradycardia during hypotensive hemorrhage. Mean arterial pressure (MAP), heart rate (HR), and renal sympathetic nerve activity (RSNA) were measured in conscious rats during either hemorrhage or cardiopulmonary receptor stimulation with phenylbiguanide (PBG) after intracerebroventricular injection of the 5-HT1/5-HT2-receptor antagonist, methysergide (40 microg). Progressive hemorrhage caused an initial rise (109 +/- 33%) followed by a fall in RSNA (-60 +/- 7%) and a fall in HR (-126 +/- 7 beats/min). Methysergide delayed the hypotension and prevented both the sympathoinhibitory and bradycardic responses to hemorrhage. Systemic 5-HT3-receptor blockade did not influence responses to hemorrhage. The PBG infusion caused transient depressor(-25 +/- 6 mmHg), bradycardic (-176 +/- 40 beats/min), and renal sympathostimulatory (182 +/-47% baseline) responses that were not affected by central methysergide (-20 +/- 6 mmHg, -162 +/- 18 beats/min, 227 +/- 46% baseline). These data indicate that a central serotonergic receptor-mediated component contributes to the sympathoinhibitory and bradycardic responses to hypotensive hemorrhage in conscious rats. Furthermore, the same central 5-HT-receptor populations involved in reflex responses to hypotensive hemorrhage probably do not mediate the sympathoinhibitory response to cardiopulmonary chemosensitive 5-HT3 receptors.

  12. Hypotension does not alter the antinociceptive effect of nifedipine.

    PubMed

    Wong, C H; Wu, W H; Zbuzek, V K

    1998-01-01

    We explored the relationship between antinociceptive and hypotensive effects of nifedipine (NIF) injected intraperitoneally ( ip, 15 mg/kg) and epidurally (epi, 20 microM), as compared to verapamil (VER, 10 mg/kg ip) and nitroglycerin (NTG, 0.1 and 0.15 mg/kg ip). The systolic blood pressure (BP) and tail-flick (TF) latencies were measured simultaneously every 10 min for 2 hours and individual values of both measurements were correlated. The highest antinociceptive as well as hypotensive effects were both measured in the group receiving NIF epi., with the correlation coefficient r2=0.2878. Injected ip., NIF revealed similar antinociceptive effect, whereas the other studied drugs were not effective. As to the degree of hypotensive activity, NIF epi was followed by VER, NTG 0.1, NIF ip. and NTG 0.15. No significant correlation was found between BP and TF latencies in any group receiving the drugs. We concluded that the antinociceptive response, measured by the tail-flick technique, is independent of the hypotensive activity of the studied drugs, including NIF.

  13. Midodrine as a Countermeasure for Post-spaceflight Orthostatic Hypotension

    NASA Technical Reports Server (NTRS)

    Platts, Steven H.; Ziegler, Michael G.; Waters, Wendy W.; Meck, Janice V.

    2007-01-01

    Up to 30 % of astronauts exhibit post-spaceflight orthostatic hypotension due to inadequate norepinephrine release during upright posture following short duration spaceflight. We hypothesize that the (alpha)1-adrenergic agonist midodrine will be an effective countermeasure. This study is being conducted in 2 phases. The first phase is complete and consisted testing six short duration crew members. All of these subjects participated in preflight and postflight tilt testing on a control flight as well as on the test flights, where midodrine was administered after landing, 1 hour before testing. Hemodynamic variables were compared between the 2 flights. Midodrine improved stroke volume, cardiac output, systolic pressure and heart rate, without increasing vascular resistance. None of these subjects experienced orthostatic hypotension on landing day. Phase II is similar to phase I, except that midodrine is ingested in flight (near TIG) and the tilt test is performed immediately after landing on the CTV. One crewmember has completed phase II testing. This crewmember had no evidence of orthostatic hypotension or presyncope, four additional crewmembers have volunteered for this study. To date, midodrine has been shown to be a safe and effective countermeasure to post-spaceflight orthostatic hypotension.

  14. Moderate induced hypotension provides satisfactory operating conditions in maxillofacial surgery.

    PubMed

    Schindler, I; Andel, H; Leber, J; Kimla, T

    1994-05-01

    Patients scheduled for maxillofacial surgery were randomly assigned to receive isoflurane (n = 22) or nitroglycerin (n = 18) in order to induce hypotension. Surgeons, blinded for the actual level of blood pressure and the technique used for inducing hypotension, were asked to rate operating conditions on a scale from 1 to 5. Systolic arterial pressure (SAP) and mean arterial pressure (MAP) were reduced by 26% for both groups. Although blood pressure levels showed little variation throughout the induced hypotension period, scores of 2 to 5 were given significantly more often at incision and at 30 min compared to the following measuring points (P < 0.01). In total, the surgical field was rated significantly more often with a score of 1 and 2 than with a score of 3 to 5 (P < 0.01). A relation between score and SAP and/or MAP could not be found. There was also no relation between scores and the technique used for hypotension. Our data suggest that, with the exception of the first half hour of surgery, on average a SAP of 89 mmHg and a MAP of 65 mmHg were sufficient to produce satisfactory operating conditions.

  15. Treatment of Idiopathic Intracranial Hypotension With Tea: A Case Report

    PubMed Central

    Petramfar, Peyman; Mohammadi, S. Saeed; Hosseinzadeh, Farideh

    2016-01-01

    Introduction The syndrome of spontaneous intracranial hypotension has been increasingly diagnosed since its discovery through magnetic resonance imaging (MRI). It is a rare syndrome that is due to the leakage of cerebrospinal fluid (CSF) from a tear in the dura and can occur at any age, even among adolescents, but is most frequently seen among females in late middle age. Case Presentation Here, we describe a 32-year-old woman with a two-month history of headaches and occasional nausea and vomiting (N/V). MRI without gadolinium was normal, but meningeal enhancement was seen in MRI with gadolinium. The lumbar puncture revealed a low opening pressure. Computed tomography myelography (CT myelography) showed no leakage; Therefore, idiopathic intracranial hypotension was diagnosed. Treatment was started using tea, and the patient’s headache got significantly better in about a day. Conclusions Conservative therapy, such as bed rest and caffeine treatment with eight cups of tea daily, yielded a significant improvement in our patient. Effectively, the patient constitutes a case of idiopathic intracranial hypotension due to undetectable CSF leakage or hyper-absorption, with good response to conservative management through tea-drinking. Further investigations with an appropriate sample size are needed in order to confirm this intervention in the treatment of idiopathic intracranial hypotension. PMID:27621920

  16. Effect of hemorrhage on cardiac output, vasopressin, aldosterone, and diuresis during immersion in men

    NASA Technical Reports Server (NTRS)

    Greenleaf, J. E.; Simanonok, K.; Bernauer, E. M.; Wade, C. E.; Keil, L. C.

    1992-01-01

    The purpose of this research was to test the hypotesis that a reduction in blood volume would attenuate or eliminate immersion-induced increases in cardiac output (Q(sub co)) and urine excretion, and to investigate accompanying vasoactive and fluid-electrolyte hormonal responses. Eight men (19-23 yr) were supine during a 2-hr control period in air, and then sat for 5-hr test periods in air at 20 C (dry control, DC); water at 34.5 C (wet control, WC); and water (34.5 C) after hemorrhage (WH) of 14.8 plus or minus 0.3 percent of their blood volume. Blood volume was -11.6 plus or minus 0.6 percent at immersion (time 0). Mean (bar-X hrs 1-5) Q(sub co) was unchanged in WC (5.3 plus or minus 0.01 l/min) and in WH (4.5 plus or minus 0.1 l/min), but decreased (P less than 0.05) in DC to 3.6 plus or minus 0.1 l/min. Mean urine excretion rates were 1.0 plus or minus 0.2 ml/min for DC and 1.1 plus or minus 0.2 ml/min for WH; both were lower (P less than 0.05) than that for WC of 2.0 plus or minus 0.4 ml/min. Plasma (Na+) and (Osm) were unchanged in all experiments. Mean plasma vasopressin (PVP) (bar-X hrs 1-5) was 1.1 plus or minus 0.1 pg/ml in WC, and higher (P less than 0.05) in DC (2.1 plus or minus 0.2 pg/ml)and WH (2.1 plus or minus 0.1 pg/ml); it was unchanged during air and water test periods. Thus, hemorrhage attenuated the immersion-induced increase in Q(sub co), eliminated the WC diuresis, maintained plasma renin activity and PVP at DC levels and did not change immersion-induced aldosterone suppression; the osmotic diuresis during control immersion is apparently not due to either aldosterone suppression or vasopressin suppression.

  17. Pressure-natriuresis and -diuresis in transgenic rats harboring both human renin and human angiotensinogen genes.

    PubMed

    Dehmel, B; Mervaala, E; Lippoldt, A; Gross, V; Bohlender, J; Ganten, D; Luft, F C

    1998-12-01

    The hypertensive double transgenic rat harboring both the human renin and human angiotensinogen genes (dTGR) offers a unique opportunity to study the human renin-angiotensin system in an experimental animal model. Since nothing is known about the control of sodium and water excretion in these rats, this study was performed to compare pressure-natriuresis relationships in hypertensive dTGR and normotensive control rats harboring only the human renin gene (hREN), in order to determine how the pressure-natriuresis relationship is reset in hypertensive dTGR. To differentiate between extrinsic and intrinsic renal mechanisms, experiments were performed with and without renal denervation, and with and without infusions of vasopressin, norepinephrine, 17-OH-corticosterone, and aldosterone. Human and rat angiotensinogen and renin mRNA expression were also determined. In hREN without controlled renal function, urine flow and sodium excretion increased from 13 to 169 microl/min per g kidney wet weight (kwt) and from 1 to 30 micromol/min per g kwt, respectively, as renal perfusion pressure was increased from 67 to 135 mmHg. Renal blood flow (RBF) and GFR ranged between 3 to 7 and 0.9 to 1.5 ml/min per g kwt. In dTGR, pressure-natriuresis-diuresis relationships were shifted approximately 40 mmHg rightward. RBF was lower in dTGR than in hREN; GFR was not different. In dTGR with neurohormonal factors controlled, RBF was decreased and pressure-natriuresis-diuresis curves were not different compared to dTGR curves without these interventions. By light microscopy, the kidneys of these 6-wk-old dTGR and hREN rats were normal and indistinguishable. Both human and rat renin and angiotensinogen mRNA were expressed in the kidneys of dTGR. The two renin mRNA were decreased in dTGR, indicating a physiologic downregulation of renin gene expression by high BP. It is concluded that the renal pressure-natriuresis mechanism is reset toward higher pressure levels in dTGR and participates in the

  18. Pilot Study: Colostomy and Urine Collection Protocol for Investigating Potential Inciting Causes of Hen Diuresis Syndrome.

    PubMed

    Jones, Kelli; Turner, Bradley; Brandão, João; Hubbard, Sue Ann; Magee, Danny; Baughman, Brittany; Wills, Robert; Tully, Thomas

    2015-06-01

    Hen diuresis syndrome has emerged over the past 5 yr as a significant cause of mortality in the U.S. broiler breeder industry. The condition affects hens in production and is characterized by transient muscle weakness in the vent region, transient diuresis, and often urate deposits on the skin below the vent. Affected hens are often seen straining to lay an egg, which suggests oviduct contraction is also impaired. Related hen mortality, often reaching 1% or more a week, is believed to be primarily the result of male aggression of the vent region (Turner et al., "Investigating Causes of Excessive Urate Production in Broiler Breeder Hens Associated with Peritonitis and Cannibalism Mortality," Oral Presentation at The American Association of Avian Pathologists Annual Meeting, p. 139, 2010). The exact association between the cause of mortality and this syndrome is unknown, but it may be the consequence of transient partial to full oviduct prolapse, which predisposes or stimulates cannibalism and aggression. Based on unpublished work done prior to this study (Turner et al., ibid.), the evidence suggests the underlying problem is metabolic. We feel that urine collection and analysis is an essential component to understanding this condition. This study serves as a pilot study for future investigations that attempt to identify the nature and cause of the metabolic disturbance through paired urine and serum collection and analysis. For the purpose of this study, a small sample of 10 affected and 10 unaffected birds was used for sample collection. In order to collect pure urine, the birds were surgically colostomized. Colostomy did prove to be a useful means of collecting urine free of feces, and for the purposes of our study it yielded adequate urine samples for analysis. There were statistically relevant urine values observed. Affected birds had a higher presence of blood in the urine, a lower uric acid excretion rate (mg/hr), higher concentration (mEq/L) of urine Na+, and

  19. Acute Electrocardiographic ST Segment Elevation May Predict Hypotension in a Swine Model of Severe Cyanide Toxicity

    DTIC Science & Technology

    2012-04-21

    induced shock, 30 swine were anesthetized and monitored and then intoxicated with a continuous cyanide infusion until severe hypotension (50 % of...TOXICOLOGY INVESTIGATION Acute Electrocardiographic ST Segment ElevationMay Predict Hypotension in a Swine Model of Severe Cyanide Toxicity Tylan A...Toxicology 2012 Abstract Cyanide causes severe cardiac toxicity resulting in tachycardia, hypotension, and cardiac arrest; however, the clinical diagnosis can

  20. Prevention of supine hypotensive syndrome in pregnant women treated with transcranial magnetic stimulation.

    PubMed

    Kim, Deborah Rubin; Wang, Eileen

    2014-08-15

    In our studies of transcranial magnetic stimulation in pregnant women with major depressive disorder, two subjects had an episode of supine hypotensive syndrome and one subject had an episode of dizziness without hypotension. Prevention of the supine hypotensive syndrome in pregnant women receiving transcranial magnetic stimulation is described.

  1. Hypotensive effects of resistance exercises with blood flow restriction.

    PubMed

    Neto, Gabriel R; Sousa, Maria S C; Costa, Pablo B; Salles, Belmiro F; Novaes, Giovanni S; Novaes, Jefferson S

    2015-04-01

    The effects of low-intensity resistance exercise (RE) combined with blood flow restriction (BFR) on blood pressure (BP) are an important factor to be considered because of the acute responses imposed by training. The aim of this study was to compare the hypotensive effect of RE performed with and without BFR in normotensive young subjects. After 1 repetition maximum (1RM) tests, 24 men (21.79 ± 3.21 years; 1.72 ± 0.06 m; 69.49 ± 9.80 kg) performed the following 4 experimental protocols in a randomized order: (a) high-intensity RE at 80% of 1RM (HI), (b) low-intensity RE at 20% of 1RM (LI), (c) low-intensity RE at 20% of 1RM combined with partial BFR (LI + BFR), and (d) control. Analysis of systolic blood pressure (SBP) and diastolic blood pressure (DBP) was conducted over a 60-minute period. The 3 RE protocols resulted in hypotensive SBP (HI = -3.8%, LI = -3.3%, LI + BFR = -5.5%) responses during the 60 minutes (p ≤ 0.05). The LI + BFR protocol promoted hypotensive (-11.5%) responses in DBP during the 60 minutes (p ≤ 0.05), and both the HI and LI + BFR protocols resulted in mean blood pressure (MBP) hypotension between 30 (-7.0%, -7.7%) and 60 minutes (-3.6%, -8.8%), respectively. In conclusion, postexercise hypotension may occur after all 3 exercise protocols with greater reductions in SBP after HI and LI + BFR, in DBP after LI + BFR, and in MBP after HI and LI + BFR protocols.

  2. Bionic baroreceptor corrects postural hypotension in rats with impaired baroreceptor.

    PubMed

    Hosokawa, Kazuya; Ide, Tomomi; Tobushi, Tomoyuki; Sakamoto, Kazuo; Onitsuka, Ken; Sakamoto, Takafumi; Fujino, Takeo; Saku, Keita; Sunagawa, Kenji

    2012-09-04

    Impairment of the arterial baroreflex causes orthostatic hypotension. Arterial baroreceptor sensitivity degrades with age. Thus, an impaired baroreceptor plays a pivotal role in orthostatic hypotension in most elderly patients. There is no effective treatment for orthostatic hypotension. The aims of this investigation were to develop a bionic baroreceptor (BBR) and to verify whether it corrects postural hypotension. The BBR consists of a pressure sensor, a regulator, and a neurostimulator. In 35 Sprague-Dawley rats, we vascularly and neurally isolated the baroreceptor regions and attached electrodes to the aortic depressor nerve for stimulation. To mimic impaired baroreceptors, we maintained intracarotid sinus pressure at 60 mm Hg during activation of the BBR. Native baroreflex was reproduced by matching intracarotid sinus pressure to the instantaneous pulsatile aortic pressure. The encoding rule for translating intracarotid sinus pressure into stimulation of the aortic depressor nerve was identified by a white noise technique and applied to the regulator. The open-loop arterial pressure response to intracarotid sinus pressure (n=7) and upright tilt-induced changes in arterial pressure (n=7) were compared between native baroreceptor and BBR conditions. The intracarotid sinus pressure-arterial pressure relationships were comparable. Compared with the absence of baroreflex, the BBR corrected tilt-induced hypotension as effectively as under native baroreceptor conditions (native, -39±5 mm Hg; BBR, -41±5 mm Hg; absence, -63±5 mm Hg; P<0.05). The BBR restores the pressure buffering function. Although this research demonstrated feasibility of the BBR, further research is needed to verify its long-term effect and safety in larger animal models and humans.

  3. Posterior reversible encephalopathy syndrome in setting of postobstructive diuresis and persistent hypocalcemia.

    PubMed

    Gera, Dinesh N; Patil, Sachin B; Parikh, Mitul; Modi, Pranjal R; Kute, Vivek B; Trivedi, Hargovind L

    2012-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinicoradiographic entity of heterogenous etiologies, which are grouped together because of similar findings on neuroimaging studies, associated with similar symptom complex of headache, vision loss, altered mentation, and seizures. In this report, we describe a case of PRES in setting of postobstructive diuresis in a 5-year-old male child, whose solitary functioning kidney was obstructed by a 1.6-cm radio-opaque stone, who after percutaneous nephrostomy (PCN) diversion developed persistent hypocalcemia which persisted despite maximum replacement by iv calcium gluconate drip, and the child developed repeated generalized tonic clonic convulsions and became unconscious for 4 days. Computerized tomography (CT) scan of the brain showed typical hypodensities in bilateral occipitoparietal regions suggesting PRES. Ultimately, over a period of 4 days, his hypocalcemia could be corrected and the child was neurologically normal on the 5th day. CT scan of the brain after a month was free of any hypodensities.

  4. Dominant factors that govern pressure natriuresis in diuresis and antidiuresis: a mathematical model.

    PubMed

    Moss, Robert; Layton, Anita T

    2014-05-01

    We have developed a whole kidney model of the urine concentrating mechanism and renal autoregulation. The model represents the tubuloglomerular feedback (TGF) and myogenic mechanisms, which together affect the resistance of the afferent arteriole and thus glomerular filtration rate. TGF is activated by fluctuations in macula densa [Cl(-)] and the myogefnic mechanism by changes in hydrostatic pressure. The model was used to investigate the relative contributions of medullary blood flow autoregulation and inhibition of transport in the proximal convoluted tubule to pressure natriuresis in both diuresis and antidiuresis. The model predicts that medullary blood flow autoregulation, which only affects the interstitial solute composition in the model, has negligible influence on the rate of NaCl excretion. However, it exerts a significant effect on urine flow, particularly in the antidiuretic kidney. This suggests that interstitial washout has significant implications for the maintenance of hydration status but little direct bearing on salt excretion, and that medullary blood flow may only play a signaling role for stimulating a pressure-natriuresis response. Inhibited reabsorption in the model proximal convoluted tubule is capable of driving pressure natriuresis when the known actions of vasopressin on the collecting duct epithelium are taken into account.

  5. Ibuprofen can induce syndrome of inappropriate diuresis in healthy young patients.

    PubMed

    Roche, Céline; Ragot, Céline; Moalic, Jean-Luc; Simon, Fabrice; Oliver, Manuela

    2013-01-01

    A 30-year-old caucasian woman, without past medical history or known drug use, was admitted to the emergency department for persistent fever and arthralgias. The laboratory analysis showed moderate hypoosmolar hyponatremia (Na: 132 mmol/L, osmolality: 239 mOsm/L), normal sodium excretion (<20 mmol/L), and a high urinary osmolality (415 mOsm/L). Later, she deteriorated with seizures and deeper hyponatremia (Na: 113 mmol/L) and so was moved to the critical care unit. At first, no obvious aetiology was found, the patient was euvolemic, as she was well hydrated and lacked concerning findings of heart failure, renal disease, or liver cirrhosis. A syndrome of inappropriate diuresis (SIAD) was proposed, and corrective measures were started immediately to reduce her hyponatremia, including restriction of fluid intake. The administration of intravenous hypertonic saline solution permitted normal neurological status to be restored and corrected the sodium concentration but induced reversible acute renal failure. Further investigation revealed that the patient had ingested 8 g ibuprofen two days before admission. After other aetiologies were ruled out, drug-induced SIAD due to ibuprofen was the most likely diagnosis for this patient. SIAD-associated hyponatremia and acute renal failure are rare side effects of nonsteroidal anti-inflammatory drugs, particularly in young people. Therefore, this case may represent a unique case of NSAID-induced SIAD and highlight the need to obtain thorough medication histories and exclude all other potential causes in hyponatremic patients.

  6. The role of atrial natriuretic peptide (ANP) in cold-induced diuresis (CID)

    SciTech Connect

    Agnew, J.W.; Freund, B.J.; DuBose, D.A.; McKay, J.M.; Hashiro, G.M. Tripler Army Medical Center, Honolulu, HI )

    1991-03-11

    The hormonal control of cold-induced diuresis (CID) remains unresolved. This study investigated the role of ANP, plasma vasopressin (AVP), and aldosterone (ALDO) on CID. Four semi-nude men participated in a 210 min exposure to 15C and 29C air, on separate days. These subjects drank 300 mL of water and had an intravenous saline drip throughout both exposures to replace blood and insensible fluid losses. CID was observed in 15C but not in the 29C experiment, as indicated by a greater urine output. In 15C, atrial natriuretic peptide (ANP) increased after 90 min by 41% and remained elevated for 2 h relative to 29C. No differences were observed in AVP between 15C and 29C. In the 15C versus the 29C experiment, ALDO was approximately 37% lower at the pre, 15 and 90 min time periods. Mean arterial blood pressure was generally greater but only significant at 60 min during the 15C versus the 29C experiment. Urinary NA{sup +} excretion was elevated in 15C relative to 29C while no difference in K{sup +} excretion was observed. Although pressure effects may contribute, the observed natriuresis in the absence of a kaliuresis in the cold suggests a physiological role of ANP in CID.

  7. Dominant factors that govern pressure natriuresis in diuresis and antidiuresis: a mathematical model

    PubMed Central

    Layton, Anita T.

    2014-01-01

    We have developed a whole kidney model of the urine concentrating mechanism and renal autoregulation. The model represents the tubuloglomerular feedback (TGF) and myogenic mechanisms, which together affect the resistance of the afferent arteriole and thus glomerular filtration rate. TGF is activated by fluctuations in macula densa [Cl−] and the myogefnic mechanism by changes in hydrostatic pressure. The model was used to investigate the relative contributions of medullary blood flow autoregulation and inhibition of transport in the proximal convoluted tubule to pressure natriuresis in both diuresis and antidiuresis. The model predicts that medullary blood flow autoregulation, which only affects the interstitial solute composition in the model, has negligible influence on the rate of NaCl excretion. However, it exerts a significant effect on urine flow, particularly in the antidiuretic kidney. This suggests that interstitial washout has significant implications for the maintenance of hydration status but little direct bearing on salt excretion, and that medullary blood flow may only play a signaling role for stimulating a pressure-natriuresis response. Inhibited reabsorption in the model proximal convoluted tubule is capable of driving pressure natriuresis when the known actions of vasopressin on the collecting duct epithelium are taken into account. PMID:24553433

  8. [Role of paraventricular nucleus in natriuresis and diuresis induced by volume expansion in rabbits].

    PubMed

    Zhang, B; Lin, M Z; Han, G C

    2000-02-01

    In sham-lesioned and paraventricular nucleus (PVN) lesioned rabbits, the peak increases of urine volume (UV) induced by volume expansion (VE) were 0.59+/-0.09 and 0.31+/-0.03 ml/min (P<0.01) respectively, whereas the peak increases of U(Na)V were respectively 66.76+/-6.74 and 36.05+/-3.44 micromol/min (P<0.01). No significant differences were found in the two increases induced by VE between rabbits with intact and those with sham-lesioned PVN. In rabbits with vagotomy there were no changes in the two increases after PVN lesion (P>0.05). In rabbits with renal denervation there was no significant change in natriuretic response after PVN lesion (P>0.05), but lesion of PVN significantly attenuated diuretic response (P<0.02). There were no significant differences in glomerular filtration rate (GFR) and renal plasma flow (RPF) before or after VE between the rabbits with intact and lesioned PVN (P>0.05). These results suggest that PVN is involved in the regulation of natriuresis and diuresis induced by VE, which are mediated by vagal afferent nerve, whereas the renal sympathetic efferent nerve may be involved in natriuretic response.

  9. The Effect of Diuresis on the Paced QRS Complexes in Pacing-Dependent Patients with Heart Failure.

    PubMed

    Sheng, Fuqiang; Chen, Bin; He, Maorong; Zhang, Meilin; Shen, Guoying; Zhao, Xiaowei

    2016-03-01

    Augmentation of the amplitude of QRS complexes with diuretic therapy for patients with congestive heart failure has been well documented. However, the effect of diuresis on the paced QRS complexes in pacing-dependent patients with heart failure is scarce. To investigate the effect of diuresis on the paced QRS complexes in pacing-dependent patients with heart failure. Thrity-two consecutive pacing-dependent patients with heart failure were enrolled in this study. Before and after diuresis, the sums of paced QRS amplitude of leads I+II (ΣpQRSI+II ), six limb leads (ΣpQRS6L ), leads V1 -V3 (ΣpQRSV1-V3 ), leads V4 -V6 (ΣpQRSV4-V6 ), leads V1 -V6 (ΣpQRSV1-V6 ), and lead aVR (pQRSaVR ), paced QRS duration (pQRSd ), paced QT intervals (pQT) and the body weight of each patient were measured, then the % changes (Δ%) in paced electrocardiogram (ECG) variables and the Δ% in body weight were evaluated. Compared with before diuresis, paced ECG variables significantly increased and body weight significantly decreased after diuresis, Δ% in paced QRS amplitude(s) in all ECG variables (ΣpQRSI+II, ΣpQRS6L, ΣpQRSV1-V3 , ΣpQRSV4-V6 , ΣpQRSV1-V6 , and pQRSaVR ) correlated well with Δ% in body weight (r = 0.416, r = 0.849, r = 0.901, r = 0.371, r = 0.837, r = 0.619, and P = 0.018, P < 0.001, P < 0.001, P = 0.037, P < 0.001, P < 0.001), while there was no correlation between Δ% in pQRSd and pQT and Δ% in body weight. The changes in amplitude of paced QRS complexes may be useful for the monitoring of therapy of pacing-dependent patients with heart failure. © 2015 Wiley Periodicals, Inc.

  10. GCF Mark IV development

    NASA Technical Reports Server (NTRS)

    Mortensen, L. O.

    1982-01-01

    The Mark IV ground communication facility (GCF) as it is implemented to support the network consolidation program is reviewed. Changes in the GCF are made in the area of increased capacity. Common carrier circuits are the medium for data transfer. The message multiplexing in the Mark IV era differs from the Mark III era, in that all multiplexing is done in a GCF computer under GCF software control, which is similar to the multiplexing currently done in the high speed data subsystem.

  11. On denture marking.

    PubMed

    Borrman, H I; DiZinno, J A; Wasén, J; René, N

    1999-06-01

    During the last decades in Sweden dentures have been permanently marked with a stainless steel metal band incorporated into the acrylic and containing the patient's birth date, a special number, and "S" for Sweden. The last recommendation issued by the National Board of Health and Welfare states that "the patients shall always be offered denture marking and be informed about the benefit thereof. Denture marking is not permitted if the patient refuses it". Requirements for denture markers have been that they should be biologically inert (when incorporated into the denture), not be expensive, be easy to inscribe, be possible to retrieve after an accident, and survive elevated temperatures for a reasonable time under normal circumstances. Although the frequency of edentulousness has decreased in recent years due to the improvement in oral health there remains a need to address the issue of marking of complete dentures, because there is a large variation in the oral status of populations in different countries. Given that only one marked denture can reveal the identity of a deceased person when all other methods fail to do so, makes it worthwhile. Furthermore, denture marking is important in long-term care facilities. We have investigated the issue of denture marking in Europe and in the United States. The results from the European survey show that denture marking is, to our knowledge regulated by law only in Sweden and Iceland. In the US denture marking is so far mandatory in 21 states while New York State requires dentures to be marked if the patient requests it and several other states impose the obligation to mark dentures on long-term care facilities. Since there is no international consensus regarding the issue of denture marking it is important to address it. A survey from the Nordic countries has shown that if denture marking was in general use, the contribution to the establishment of identity by forensic odontology in cases of fire would increase by about 10

  12. Marking as Judgment

    ERIC Educational Resources Information Center

    Brooks, Val

    2012-01-01

    An aspect of assessment which has received little attention compared with perennial concerns, such as standards or reliability, is the role of judgment in marking. This paper explores marking as an act of judgment, paying particular attention to the nature of judgment and the processes involved. It brings together studies which have explored…

  13. Minoxidil for severe hypertension after failure of other hypotensive drugs.

    PubMed Central

    Devine, B L; Fife, R; Trust, P M

    1977-01-01

    Forty-four patients with severe hypertension who were resistant to treatment with more conventional hypotensive drugs or could not tolerate the side effects were treated with minoxidil, a potent peripheral vasodilator. A beta-blocking drug and a diuretic were used routinely to control, respectively, the tachycardia and fluid retention caused by minoxidil. During treatment the outpatient supine blood pressure fell from a mean of 221/134 mm Hg to 162/98 mm Hg. Eleven patients required additional or alternative hypotensive agents before blood pressure was adequately controlled. Side effects were minor, although the invariable hirsuties caused by minoxidil was unacceptable to three women. The possibility of cardiotoxic effects, raised by early studies in dogs, has not been excluded, and therefore this drug should be used only in patients with severe hypertension. In such patients minoxidil appears to be most effective. PMID:902045

  14. Dose-dependent radiation-induced hypotension in the canine

    SciTech Connect

    Cockerham, L.G.; Hampton, J.D.; Doyle, T.F.

    1986-01-01

    Radiation-induced early transient incapacitation (ETI) is often accompanied by severe systemic hypotension. However, postradiation hypotension does not occur with equal frequency in all species and is not reported with consistency in the canine. In an attempt to clarify the differences in reported canine post-radiation blood pressures, canine systemic blood pressures were determined both before and after exposure to gamma radiation of either 80 or 100 Gy. Data obtained from six sham-radiated beagles and 12 radiated beagles indicated that 100-Gy, whole-body, gamma radiation produced a decrease in systemic mean blood pressure while 80-Gy, whole-body, gamma radiation did not. Analysis of this data could be consistent with a quantal response to a gamma radiation dose between 80 Gy and 100 Gy.

  15. New optimized piperamide analogues with potent in vivo hypotensive properties.

    PubMed

    de Mattos Duarte, Carolina; Verli, Hugo; de Araújo-Júnior, João Xavier; de Medeiros, Isac Almeida; Barreiro, Eliezer J; Fraga, Carlos Alberto Manssour

    2004-12-01

    We describe herein the structural optimization of new piperamide analogues, designed from two natural prototypes, piperine 1 and piperdardine 2, obtained from Piper tuberculatum Jacq. (Piperaceae). Molecular modeling studies using semiempirical AM1 method were made in order to establish rational modifications to optimize them by molecular simplification. The targeted compounds (10) and (11) were respectively obtained using benzaldehyde (12) and para-anisaldehyde (13) as starting materials. 1H NMR spectra showed that the target compounds were diastereoselectively obtained as the (E)-isomer, the same geometry of the natural prototypes. These new synthetic amides presented significant hypotensive effects in cardiovascular essays using in vivo methodologies. Compound 11 (N-[5-(4'-methoxyphenyl)-2(E)-pentenoyl]thiomorpholine) showed a potency 10,000 times greater than its prototype 5, evidencing an optimization of the molecular architecture for this class of hypotensive drug candidates.

  16. Persistent orthostatic headache without intracranial hypotension: which treatment?

    PubMed

    Curone, M; Cecchini, A Proietti; Chiapparini, L; D'Amico, D

    2015-05-01

    Orthostatic headache can be the leading symptom of intracranial hypotension, however, not all orthostatic headaches are due to cerebrospinal fluid leaks and these forms can be a clinical problem, especially for treatment. Aim of this study was to review patients with persistent orthostatic headache in whom a detailed head and spinal MRI follow-up did not reveal any sign of intracranial hypotension and to evaluate which treatment can be considered the first choice. Patients admitted to our headache center for evaluation of persistent orthostatic headache and followed after first admission with clinical and neuroradiological controls were systematically reviewed. 11 patients (7 M, 4 F) followed in a period lasted from 10 months up to 2 years were studied. Six patients (54, 5 %) reported a MRI performed previously elsewhere with a suspect diagnosis of intracranial hypotension which was not confirmed at MRI at our hospital such as during the radiological follow-up. Three patients (27.2 %) had developed orthostatic headache short after a neck or head trauma with no evidence of neuroradiological pathological signs and two patients (18 %) had a previous history of psychiatric disorder. We administrated antidepressants in five patients, atypical neuroleptic in three patients, association of antidepressant and antipsychotic in one patient and muscle relaxants in two cases. All patients showed a certain improvement of headache in the weeks after introduction of the pharmacological treatment; six (54, 5 %) had pain relief during the follow-up and five (45, 5 %) were pain free at the last clinical control. We found out that patients with the best outcome were the ones treated with antidepressants. Persistent orthostatic headache without any neuroradiological sign of intracranial hypotension is a challenging problem for clinicians. Although the International Classification of Headache Disorders (ICHD-3 beta version) criteria suggests the possibility of epidural blood patch in

  17. Caffeine and diuresis during rest and exercise: A meta-analysis

    PubMed Central

    Coca, Aitor; Casa, Douglas J.; Antonio, Jose; Green, James M.; Bishop, Phillip A.

    2016-01-01

    Objectives Although ergogenic, acute caffeine ingestion may increase urine volume, prompting concerns about fluid balance during exercise and sport events. This meta-analysis evaluated caffeine induced diuresis in adults during rest and exercise. Design Meta-analysis. Methods A search of three databases was completed on November 1, 2013. Only studies that involved healthy adults and provided sufficient information concerning the effect size (ES) of caffeine ingestion on urine volume were included. Sixteen studies met the inclusion criteria, providing a total of 28 ESs for the meta-analysis. Heterogeneity was assessed using a random-effects model. Results The median caffeine dosage was 300 mg. The overall ES of 0.29 (95% confidence interval (CI) = 0.11-0.48, p = 0.001) corresponds to an increase in urine volume of 109 ± 195 mL or 16.0 ± 19.2% for caffeine ingestion vs. non-caffeine conditions. Subgroup meta-analysis confirmed exercise as a strong moderator: active ES = 0.10, 95% CI = −0.07 to 0.27, p = 0.248 vs. resting ES = 0.54, 95% CI = 0.22–0.85, p = 0.001 (Cochran's Q, p = 0.019). Females (ES = 0.75,95% CI = 0.38–1.13, p< 0.001) were more susceptible to diuretic effects than males (ES = 0.13,95% CI = −0.05 to 0.31, p = 0.158) (Cochran's Q, p = 0.003). Conclusions Caffeine exerted a minor diuretic effect which was negated by exercise. Concerns regarding unwanted fluid loss associated with caffeine consumption are unwarranted particularly when ingestion precedes exercise. PMID:25154702

  18. (18)F-FDG PET/CT delayed images with forced diuresis for revaluating abdominopelvic malignancies.

    PubMed

    Wang, Hui-Chun; Wang, Zhi-Min; Wang, Yu-Bin; Chen, Xiao-Hong; Cui, Lan-Lan

    2017-05-01

    The aim of this retrospective study was to evaluate the role of delayed images after forced diuresis coupled with oral hydration in abdominopelvic (18)F-FDG PET/CT. Forty-six patients consisting of 17 urological diseases, 9 gynecological tumors, 18 colorectal malignancies, and 2 cancers of unknown primary site were retrospectively analyzed. All patients who presented with indeterminate or equivocal abdominopelvic foci on standard (18)F-FDG PET/CT underwent a delayed abdominopelvic imaging after administration of 20 mg furosemide intravenously and extra water intake of 500 mL. PET/CT images before and after furosemide were compared with each other and their findings correlated with pathology or clinical follow-up (>6 months). On initial PET/CT, the glucose metabolism characters of lesions were disguised by radioactive urine, or some undetermined (18)F-FDG accumulating foci near the urinary tract appeared. While postdiuretic PET/CT demonstrated an excellent urinary tracer washout, and hypermetabolic lesions could be clearly detected and precisely localized in all cases. On the other hand, the suspected active foci caused by potential stagnation of excreted (18)F-FDG in urinary tract were eliminated. The sensitivity, specificity, and accuracy were 94.4% (34/36), 8/10, 91.3% (42/46), respectively. Furthermore, the additional lesions with surrounding invasion or locoregional metastasis were discovered in 8 of 46 (17.4%) patients only by the delayed images, including 2 gynecological and 6 rectal malignancies. Detection of abdominopelvic malignancies can be improved using delayed (18)F-FDG PET/CT images after a diuretic and oral hydration.

  19. Ibuprofen Can Induce Syndrome of Inappropriate Diuresis in Healthy Young Patients

    PubMed Central

    Roche, Céline; Ragot, Céline; Moalic, Jean-Luc; Simon, Fabrice; Oliver, Manuela

    2013-01-01

    A 30-year-old caucasian woman, without past medical history or known drug use, was admitted to the emergency department for persistent fever and arthralgias. The laboratory analysis showed moderate hypoosmolar hyponatremia (Na: 132 mmol/L, osmolality: 239 mOsm/L), normal sodium excretion (<20 mmol/L), and a high urinary osmolality (415 mOsm/L). Later, she deteriorated with seizures and deeper hyponatremia (Na: 113 mmol/L) and so was moved to the critical care unit. At first, no obvious aetiology was found, the patient was euvolemic, as she was well hydrated and lacked concerning findings of heart failure, renal disease, or liver cirrhosis. A syndrome of inappropriate diuresis (SIAD) was proposed, and corrective measures were started immediately to reduce her hyponatremia, including restriction of fluid intake. The administration of intravenous hypertonic saline solution permitted normal neurological status to be restored and corrected the sodium concentration but induced reversible acute renal failure. Further investigation revealed that the patient had ingested 8 g ibuprofen two days before admission. After other aetiologies were ruled out, drug-induced SIAD due to ibuprofen was the most likely diagnosis for this patient. SIAD-associated hyponatremia and acute renal failure are rare side effects of nonsteroidal anti-inflammatory drugs, particularly in young people. Therefore, this case may represent a unique case of NSAID-induced SIAD and highlight the need to obtain thorough medication histories and exclude all other potential causes in hyponatremic patients. PMID:23840216

  20. The effects of diuresis and transfusion on pulmonary function in children with thalassemia major.

    PubMed

    Lands, L C; Woods, S; Katsardis, C; Desmond, K; Coates, A L

    1991-01-01

    Previous pulmonary function studies in subjects with thalassemia major (TM) who were on regular transfusion programs have demonstrated results ranging from small airway obstruction to a restrictive pattern. Ten subjects with TM were studied pre- and postdiuresis, and again 24 hr after transfusion, in order to evaluate the role of possible fluid overload in altering pulmonary function. Subjects underwent spirometry and had lung volume and flow volume curves (MEFVC) measured in a volume displacement plethysmograph while breathing air and a mixture of 80% helium and 20% oxygen (HeO2). Six patients had pulmonary mechanics measured with esophageal balloons in place. Baseline function was normal and no change occurred following diuresis. Following transfusion, the volume of isoflow (VisoV) decreased, but other parameters did not change. Subsequent analysis revealed 5 subjects with an initial VisoV greater than 20 (% FVC) but, paradoxically, less evidence of flow limitation in the small airways than those with a VisoV less than 20 (% FVC). Posttransfusion, in those subjects with an initially high VisoV, the Vmax25(air) tended to fall without a change of MEFVC in HeO2, resulting in a decreased VisoV. This was interpreted as evidence of subtle abnormalities in the small airways caused by volume expansion, raising doubts about the value of the VisoV as a measure of small airway disease. As a group, our subjects did not demonstrate any abnormalities in baseline function. Some subjects had mild flow limitation in small airway while other developed comparable levels of flow limitation following the volume expansion associated with transfusion.

  1. A randomized crossover clinical trial of sertraline for intradialytic hypotension.

    PubMed

    Razeghi, Effat; Dashti-Khavidaki, Simin; Nassiri, Samira; Abolghassemi, Rozita; Khalili, Hossein; Hashemi Nazari, Seyed Saeed; Mansournia, Mohammad Ali; Taraz, Mohammad

    2015-07-01

    Intradialytic hypotension (IDH) has been reported in 15% to 50% of hemodialysis patients and increases patients morbidity and mortality. Some small noncontrolled studies evaluated the effect of sertraline on IDH with conflicting results. This study is a randomized crossover controlled trial on the effectiveness of sertraline to reduce IDH. Patients on hemodialysis who suffered IDH in at least 50% of their dialysis sessions were enrolled. Each patient received either sertraline or placebo for 4 weeks and after a 4-week washout period, was switched to the other arm of the trial. All patients started sertraline at a daily dose of 50 mg that increased to 100 mg after 1 week. Twelve patients completed all phases of the study. Sertraline therapy increased nadir intradialysis diastolic and systolic blood pressure by 3.8 mm Hg and 4.9 mm Hg at the end of the intervention, respectively. Sertraline therapy also significantly increased postdialysis diastolic and systolic blood pressure by 6.0 mm Hg and 8.7 mm Hg. Sertraline therapy significantly reduced the risk of hypotension episodes by 43%. The improvement of intradialysis and postdialysis diastolic and systolic blood pressure were only significant in nondiabetic patients. Sertraline therapy significantly increases intradialysis and postdialysis blood pressure. These effects of sertraline can result in significant decrease in hypotension episodes during dialysis treatment and the number of interventions required to manage IDH. However, not all patients may benefit from sertraline depending on comorbidities such as diabetes mellitus.

  2. Hemofiltration and Hemodiafiltration Reduce Intradialytic Hypotension in ESRD

    PubMed Central

    Altieri, Paolo; Andrulli, Simeone; Bolasco, Piergiorgio; Sau, Giovanna; Pedrini, Luciano A.; Basile, Carlo; David, Salvatore; Feriani, Mariano; Montagna, Giovanni; Di Iorio, Biagio Raffaele; Memoli, Bruno; Cravero, Raffaella; Battaglia, Giovanni; Zoccali, Carmine

    2010-01-01

    Symptomatic intradialytic hypotension is a common complication of hemodialysis (HD). The application of convective therapies to the outpatient setting may improve outcomes, including intradialytic hypotension. In this multicenter, open-label, randomized controlled study, we randomly assigned 146 long-term dialysis patients to HD (n = 70), online predilution hemofiltration (HF; n = 36), or online predilution hemodiafiltration (HDF; n = 40). The primary end point was the frequency of intradialytic symptomatic hypotension (ISH). Compared with the run-in period, the frequency of sessions with ISH during the evaluation period increased for HD (7.1 to 7.9%) and decreased for both HF (9.8 to 8.0%) and HDF (10.6 to 5.2%) (P < 0.001). Mean predialysis systolic BP increased by 4.2 mmHg among those who were assigned to HDF compared with decreases of 0.6 and 1.8 mmHg among those who were assigned to HD and HF, respectively (P = 0.038). Multivariate logistic regression demonstrated significant risk reductions in ISH for both HF (odds ratio 0.69; 95% confidence interval 0.51 to 0.92) and HDF (odds ratio 0.46, 95% confidence interval 0.33 to 0.63). There was a trend toward higher dropout for those who were assigned to HF (P = 0.107). In conclusion, compared with conventional HD, convective therapies (HDF and HF) reduce ISH in long-term dialysis patients. PMID:20813866

  3. Guancydine, a new hypotensive agent with complex action.

    PubMed

    Hărăgus, S T; Uza, G; Duncea, C

    1977-01-01

    Guancydine (1-cyano-3-tert-amylguanidine) lowered within normal limits the tensional values in an interval of four hours after its administration in eight out of nine hypertensive patients under experiment. The hypotensive effect of a single oral dose of 500-750 mg persists for about 6-7 hours after its administration. Guancydine does not impair the vasopressor response to angiotensin II but reduces the action of this peptide on the excretion of water, Na, K and Ca through urine. The hypotensive effect of Guancydine is associated with a decrease of platelet adhesiveness and an activation of fibrinolysis. In view of this fact, Guancydine might play a role in the prophylaxis of complications of arterial hypertension - atherosclerosis and trombosis. The increase of venous blood oxygenation after Guancydine could be attributed to the opening of arterio-venous shunts or to the reduction of tissular extraction of oxygen. Guancydine does not seem to be toxic. It produced, in some patients, slight headache and orthostatic hypotension, especially during the first hours after administration.

  4. Spontaneous intracranial hypotension syndrome: report of twelve cases.

    PubMed

    Ferrante, Enrico; Savino, Anna; Sances, Grazia; Nappi, Giuseppe

    2004-06-01

    To investigate clinical, MRI, and radioisotope findings and therapeutic outcome of the syndrome of spontaneous intracranial hypotension (SIH). Spontaneous intracranial hypotension is characterized by orthostatic headache, low CSF pressure, and MRI findings of diffuse pachymeningeal gadolinium enhancement without previous history of head trauma or lumbar puncture. Spontaneous CSF leakage from a spinal dural tear has been suggested as the underlying pathogenic mechanism of SIH. Most patients recover without sequelae, but subdural collections have been described in a few. Twelve consecutive patients (10 females, 2 males, mean age 39 years) with headache related to the syndrome of spontaneous intracranial hypotension were investigated. Eleven patients presented orthostatic headache, one patient had continuous nonpostural headache. Additional clinical symptoms included nausea, vomiting, tinnitus, diplopia, and back pain. All the patients had low CSF opening pressure, seven had increased CSF albumin, and four had pleocytosis. Brain MRI showed diffuse pachymeningeal gadolinium enhancement. Other features included subdural fluid collections (hematoma/hygroma) in four patients, downward displacement of the brain in four patients, and enlargement of the pituitary gland in one patient. Radioisotope cisternography results indicated, in two patients, a CSF leakage site in the cervico-thoracic region, and in one patient showed limited ascent of the tracer to the cerebral convexity and early appearance of radioisotope in the bladder. All the patients had complete resolution of headache with conservative treatment. Patients with SIH have distinct MRI and sometimes radioisotope cisternographic abnormalities and generally respond favorably to conservative management.

  5. Interaction with pyridoxal as a possible mechanism of hydralazine hypotension.

    PubMed

    Vidrio, H

    1990-01-01

    The mechanism by which the antihypertensive vasodilator hydralazine relaxes vascular smooth muscle is unknown. The drug interacts with pyridoxal and can produce B6 deficiency; it also inhibits a number of enzymes requiring pyridoxal as a cofactor, but there is no apparent relation between its enzymatic and blood pressure effects. To explore the possibility of a hydralazine-pyridoxal interaction at a nonenzymatic site, the acute hypotensive response to hydralazine was determined by tail cuff blood pressure (BP) measurements in conscious normotensive rats pretreated or not pretreated with pyridoxine. Other animals were pretreated with isoniazid, a drug also capable of reacting with pyridoxal. Responses to hydralazine were diminished by pyridoxine and enhanced by isoniazid; those to the vasodilator diazoxide or to the alpha-adrenergic blocker zolertine were unaffected by such pretreatments. The inhibitory effect of pyridoxine was absent when rats were pretreated with the calcium antagonists verapamil or cinnarizine. Hydralazine hypotension in anesthetized rats was also reduced by pyridoxal pretreatment. These results suggest that at least part of hydralazine-induced hypotension may be related to interaction with pyridoxal, possibly through interference with an effect of the vitamer on calcium and/or sodium transport into vascular smooth muscle.

  6. Low-Volume Intense Exercise Elicits Post-exercise Hypotension and Subsequent Hypervolemia, Irrespective of Which Limbs Are Exercised

    PubMed Central

    Graham, Matthew J.; Lucas, Samuel J. E.; Francois, Monique E.; Stavrianeas, Stasinos; Parr, Evelyn B.; Thomas, Kate N.; Cotter, James D.

    2016-01-01

    Introduction: Exercise reduces arterial and central venous blood pressures during recovery, which contributes to its valuable anti-hypertensive effects and to facilitating hypervolemia. Repeated sprint exercise potently improves metabolic function, but its cardiovascular effects (esp. hematological) are less well-characterized, as are effects of exercising upper versus lower limbs. The purposes of this study were to identify the acute (<24 h) profiles of arterial blood pressure and blood volume for (i) sprint intervals versus endurance exercise, and (ii) sprint intervals using arms versus legs. Methods: Twelve untrained males completed three cycling exercise trials; 50-min endurance (legs), and 5*30-s intervals using legs or arms, in randomized and counterbalanced sequence, at a standardized time of day with at least 8 days between trials. Arterial pressure, hemoglobin concentration and hematocrit were measured before, during and across 22 h after exercise, the first 3 h of which were seated rest. Results: The post-exercise hypotensive response was larger after leg intervals than endurance (AUC: 7540 ± 3853 vs. 3897 ± 2757 mm Hg·min, p = 0.049, 95% CI: 20 to 6764), whereas exercising different limbs elicited similar hypotension (arms: 6420 ± 3947 mm Hg·min, p = 0.48, CI: −1261 to 3896). In contrast, arterial pressure at 22 h was reduced after endurance but not after leg intervals (−8 ± 8 vs. 0 ± 7 mm Hg, p = 0.04, CI: 7 ± 7) or reliably after arm intervals (−4 ± 8 mm Hg, p = 0.18 vs. leg intervals). Regardless, plasma volume expansion at 22 h was similar between leg intervals and endurance (both +5 ± 5%; CI: −5 to 5%) and between leg and arm intervals (arms: +5 ± 7%, CI: −8 to 5%). Conclusions: These results emphasize the relative importance of central and/or systemic factors in post-exercise hypotension, and indicate that markedly diverse exercise profiles can induce substantive hypotension and subsequent hypervolemia. At least for endurance

  7. Prehospital fluid resuscitation in hypotensive trauma patients: do we need a tailored approach?

    PubMed

    Geeraedts, Leo M G; Pothof, Leonie A H; Caldwell, Erica; de Lange-de Klerk, Elly S M; D'Amours, Scott K

    2015-01-01

    The ideal strategy for prehospital intravenous fluid resuscitation in trauma remains unclear. Fluid resuscitation may reverse shock but aggravate bleeding by raising blood pressure and haemodilution. We examined the effect of prehospital i.v. fluid on the physiologic status and need for blood transfusion in hypotensive trauma patients after their arrival in the emergency department (ED). Retrospective analysis of trauma patients (n=941) with field hypotension presenting to a level 1 trauma centre. Regression models were used to investigate associations between prehospital fluid volumes and shock index and blood transfusion respectively in the emergency department and mortality at 24h. A 1L increase of prehospital i.v. fluid was associated with a 7% decrease of shock index in the emergency department (p<0.001). Volumes of 0.5-1L and 1-2L were associated with reduced likelihood of shock as compared to volumes of 0-0.5L: OR 0.61 (p=0.03) and OR 0.54 (p=0.02), respectively. Volumes of 1-2L were also associated with an increased likelihood of receiving blood transfusion in ED: OR 3.27 (p<0.001). Patients who had received volumes of >2L have a much greater likelihood of receiving blood transfusion in ED: OR 9.92 (p<0.001). Mortality at 24h was not associated with prehospital i.v. fluids. In hypotensive trauma patients, prehospital i.v. fluids were associated with a reduction of likelihood of shock upon arrival in ED. However, volumes of >1L were associated with a markedly increased likelihood of receiving blood transfusion in ED. Therefore, decision making regarding prehospital i.v. fluid resuscitation is critical and may need to be tailored to the individual situation. Further research is needed to clarify whether a causal relationship exists between prehospital i.v. fluid volume and blood transfusion. Also, prospective trials on prehospital i.v. fluid resuscitation strategies in specific patient subgroups (e.g. traumatic brain injury and concomitant haemorrhage) are

  8. Percussion, diuresis, and inversion therapy for the passage of lower pole kidney stones following shock wave lithotripsy.

    PubMed

    Liu, Liang Ren; Li, Qi Jun; Wei, Qiang; Liu, Zhen Hua; Xu, Yong

    2013-12-08

    Lower pole kidney stones typically have poor rates of spontaneous clearance from the body. Some studies have suggested that diuresis, percussion and inversion therapy could be beneficial for people with lower pole kidney stones following shock wave lithotripsy. There is however controversy about the relative benefits, harms, and efficacy of these interventions for the management of lower pole kidney stones. To identify the benefits and harms of percussion, diuresis, and inversion therapy to facilitate the passage of lower pole kidney stones following shock wave lithotripsy. We searched the Cochrane Renal Group's specialised register up to 27 November 2013 through contact with the Trials' Search Co-ordinator using search terms relevant to this review. All randomised controlled trials (RCTs) and quasi-RCTs looking at the benefits and harms of percussion, diuresis, and inversion therapy for aiding passage of lower pole kidney stones following shock wave lithotripsy were sought for assessment. The first phases of randomised cross-over studies were also eligible for inclusion. Two authors independently assessed study quality and extracted data. Results were expressed as relative risk (RR) for dichotomous outcomes and mean difference (MD) or standardised mean difference (SMD) for continuous data with 95% confidence intervals (CI). We identified two small studies (177 participants) for inclusion and analysis. One study (69 participants) compared percussion, diuresis and inversion therapy following shock wave lithotripsy versus observation-only after shock wave lithotripsy. This study reported significantly higher stone-free rates in the intervention group (RR 0.62, 95% CI 0.47 to 0.82) and a significant reduction in stone burden (MD -3.30, 95% CI -3.58 to -3.03) compared to the observation-only group. They reported no significant differences in complication rates (RR 3.00, 95% CI 0.12 to 76.24).The second study (108 participants) compared percussion, diuresis, and

  9. Marking: A Critical Alternative.

    ERIC Educational Resources Information Center

    Hull, Charles

    1984-01-01

    Having pupils critique their own work is an alternative to marking that is worthy of consideration. Pupil critique fosters in students a willingness to take responsibility for the quality of their work products. (RM)

  10. Ames Fellows Award - Mark

    NASA Image and Video Library

    Dr. Hans Mark is a leading expert in the fields of aerospace design and national defense policy. From 1969 to 1977, he served as Director of the NASA Ames Research Center. During his tenure, Ames b...

  11. Mark IVA microprocessor support

    NASA Technical Reports Server (NTRS)

    Burford, A. L.

    1982-01-01

    The requirements and plans for the maintenance support of microprocessor-based controllers in the Deep Space Network Mark IVA System are discussed. Additional new interfaces and 16-bit processors have introduced problems not present in the Mark III System. The need for continuous training of maintenance personnel to maintain a level of expertise consistent with the sophistication of the required tools is also emphasized.

  12. Nimodipine-induced hypotension but not nitroglycerin-induced hypotension preserves long- and short-term memory in adult mice.

    PubMed

    Haile, Michael; Galoyan, Samuel; Li, Yong-Sheng; Cohen, Barry H; Quartermain, David; Blanck, Thomas; Bekker, Alex

    2012-05-01

    Acute hypotension may be implicated in cognitive dysfunction. L-type calcium channel blockers in the setting of hypoxia are protective of learning and memory. We tested the hypothesis that hypotension induced by nimodipine (NIMO) and nicardipine (NICA) would be protective of long- and short-term memory compared to hypotension induced by nitroglycerin (NTG). Forty Swiss-Webster mice (30 to 35 g, 6 to 8 weeks) were randomized into 4 groups for i.p. injection immediately after passive avoidance (PA) learning on day 0: (1) NTG (30 mg/kg); (2) NICA (40 mg/kg); (3) NIMO (40 mg/kg); and (4) saline. PA training latencies (seconds) were recorded for entry from a suspended platform into a Plexiglas tube where a shock (0.3 mA; 2-second duration) was automatically delivered. On day 2 latencies were recorded during a testing trial during which no shock was delivered. Latencies >900 seconds were assigned this value. Lower testing latency is indicative of an impairment of long-term associative memory. Forty-nine additional mice were randomized into similar groups for object recognition testing (ORT) and given i.p. injections on day 0. ORT measures short-term memory by exploiting the tendency of mice to prefer novel objects where a familiar object is present. On day 5 during training, 2 identical objects were placed in a circular arena and mice explored both for 15 minutes. A testing trial was conducted 1 hour later for 3 minutes after a novel object replaced a familiar one. Mice with intact memory spend about 65% of the time exploring the novel object. Mice with impaired memory devote equal time to each object. Recognition index (RI) is defined as the ratio of time spent exploring the novel object to time spent exploring both objects was the measure of memory. Mean arterial blood pressure (MAP), cerebral bloodflow, and body and brain oxygenation (PO(2)) studies were done in separate groups of mice to determine the dosages for matched degrees of hypotension and the physiological

  13. Potential involvement of P2Y2 receptor in diuresis of postobstructive uropathy in rats.

    PubMed

    Zhang, Yue; Kohan, Donald E; Nelson, Raoul D; Carlson, Noel G; Kishore, Bellamkonda K

    2010-03-01

    AVP resistance of the medullary collecting duct (mCD) in postobstructive uropathy (POU) has been attributed to increased production of PGE2. P2Y2 receptor activation causes production of PGE2 by the mCD. We hypothesize that increased P2Y2 receptor expression and/or activity may contribute to the diuresis of POU. Sprague-Dawley rats were subjected to bilateral ureteral obstruction for 24 h followed by release (BUO/R, n = 17) or sham operation (SHM/O, n = 15) and euthanized after 1 wk or 12 days. BUO/R rats developed significant polydipsia, polyuria, urinary concentration defect, and increased urinary PGE2 and decreased aquaporin-2 protein abundance in the inner medulla compared with SHM/O rats. After BUO/R, the relative mRNA expression of P2Y2 and P2Y6 receptors was increased by 2.7- and 4.9-fold, respectively, without significant changes in mRNA expression of P2Y1 or P2Y4 receptor. This was associated with a significant 3.5-fold higher protein abundance of the P2Y2 receptor in BUO/R than SHM/O rats. When freshly isolated mCD fractions were challenged with different types of nucleotides (ATPgammaS, ADP, UTP, or UDP), BUO/R and SHM/O rats responded to only ATPgammaS and UTP and released PGE2, consistent with involvement of the P2Y2, but not P2Y6, receptor. ATPgammaS- or UTP-stimulated increases in PGE2 were much higher in BUO/R (3.20- and 2.28-fold, respectively, vs. vehicle controls) than SHM/O (1.68- and 1.30-fold, respectively, vs. vehicle controls) rats. In addition, there were significant 2.4- and 2.1-fold increases in relative mRNA expression of prostanoid EP1 and EP3 receptors, respectively, in the inner medulla of BUO/R vs. SHM/O rats. Taken together, these data suggest that increased production of PGE2 by the mCD in POU may be due to increased expression and activity of the P2Y2 receptor. Increased mRNA expression of EP1 and EP3 receptors in POU may also help accentuate PGE2-induced signaling in the mCD.

  14. Meetings with Mark Vishik

    NASA Astrophysics Data System (ADS)

    Kalikinskaya, E. I.

    2014-12-01

    Mark Iosifovich Vishik was my husband Vladimir Chepyzhov's advisor during his years as a student in the Faculty of Mechanics and Mathematics at Moscow State University, and afterwards they worked together for almost 30 years. This is why I knew him personally while not being a mathematician myself: we sometimes talked on the phone, and met during common trips and a few holidays. In his last years, after the death of his devoted wife who was also his best friend, my husband and I decided to visit Mark regularly in order to comfort him in his loneliness, and many other of his friends did the same. I can say without exaggeration that Mark loved to talk with me about everyday matters, to reminisce about his wife Asya Moiseevna, their friends and relatives, to tell stories of his youth and the wonderful encounters that had so enriched his life. We had the idea to write down our conversations and publish them as a book. Unfortunately, few such conversations lay ahead. The last one took place in January 2010. We did not write a book, but we did write an article [1], which was published in English in the form of an interview with Mark. The present article is based on our conversations with Mark. Here I will try to recount his memories about people who played an important role in his life.

  15. (68)Ga-PSMA I&T PET/CT for assessment of prostate cancer: evaluation of image quality after forced diuresis and delayed imaging.

    PubMed

    Derlin, Thorsten; Weiberg, Desiree; von Klot, Christoph; Wester, Hans-Jürgen; Henkenberens, Christoph; Ross, Tobias L; Christiansen, Hans; Merseburger, Axel S; Bengel, Frank M

    2016-12-01

    Urinary radiotracer excretion of (68)Ga-Labelled prostate-specific membrane antigen (PSMA) ligands may complicate the assessment of the prostate region and differentiation of lymph nodes from ureteral activity. The aim of this study was to assess the value of delayed imaging after forced diuresis. Sixty-six patients underwent (68)Ga-PSMA I&T PET/CT for evaluation of prostate cancer at 60 min post-injection. In subgroups of patients, this was amended by delayed imaging after 180 min post-injection, preceded by furosemide and oral hydration early, at the time of tracer injection, or delayed, at 100 min post-injection. Urinary tracer activity within the bladder and focal ureteral activity was analyzed. After forced diuresis, linear and focal visualization of ureters was significantly reduced. After delayed furosemide, mean and peak bladder activity decreased (p < 0.001), and image quality of the prostate region improved on delayed images (p < 0.001). Early furosemide co-injection with tracer resulted in increased mean and peak bladder activity (p < 0.001) and in deteriorated image quality of the prostate region on delayed images (p = 0.008). Ga-PSMA I&T PET/CT delayed imaging after forced diuresis can improve the assessment of prostate region and pelvic lymph nodes by removing excreted tracer from the lower urinary tract. • Forced diuresis can improve image quality in (68) Ga-PSMA I&T. • After forced diuresis, linear and focal visualization of ureters was reduced. • Timing of diuresis relative to (68) Ga-PSMA I&T injection is important. • Early furosemide co-injection with tracer resulted in deteriorated image quality on delayed images. • After delayed furosemide, image quality improved on delayed images.

  16. The use of vasopressin in the setting of recalcitrant hypotension due to calcium channel blocker overdose.

    PubMed

    Kanagarajan, Karthikeyan; Marraffa, Jeanna M; Bouchard, Nicole C; Krishnan, Padmanabhan; Hoffman, Robert S; Stork, Christine M

    2007-01-01

    Treatment of hypotension caused by calcium channel blocker overdose (CCB) remains a challenge. We describe the successful use of vasopressin in two patients with massive CCB overdoses in whom hypotension was unresponsive to calcium, glucagon, insulin, and conventional vasopressor therapies. While various modes of treatments have been used to treat the hypotension of CCB overdose, this is the first report to our knowledge of the successful use of vasopressin in this clinical setting.

  17. Aircraft vortex marking program

    NASA Technical Reports Server (NTRS)

    Pompa, M. F.

    1979-01-01

    A simple, reliable device for identifying atmospheric vortices, principally as generated by in-flight aircraft and with emphasis on the use of nonpolluting aerosols for marking by injection into such vortex (-ices) is presented. The refractive index and droplet size were determined from an analysis of aerosol optical and transport properties as the most significant parameters in effecting vortex optimum light scattering (for visual sighting) and visual persistency of at least 300 sec. The analysis also showed that a steam-ejected tetraethylene glycol aerosol with droplet size near 1 micron and refractive index of approximately 1.45 could be a promising candidate for vortex marking. A marking aerosol was successfully generated with the steam-tetraethylene glycol mixture from breadboard system hardware. A compact 25 lb/f thrust (nominal) H2O2 rocket chamber was the key component of the system which produced the required steam by catalytic decomposition of the supplied H2O2.

  18. The PCB mark

    SciTech Connect

    1994-12-01

    Polychlorinated biphenyls (PCBs) are a class of organic chemicals that had become widely used in industrial applications due to their practical physical and chemical properties. Historical uses of PCBs include dielectric fluids (used in utility transformers, capacitors, etc.), hydraulic fluids, and other applications requiring stable, fire-retardant materials. Due to findings that PCBs may cause adverse health effects and due to their persistence and accumulation in the environment. The Toxic Substances Control Act (TSCA), enacted on October 11, 1976, banned the manufacture of PCBs after 1978 [Section 6(e)]. The first PCB regulations, promulgated at 40 CFR Part 761, were finalized on February 17, 1978. These PCB regulations include requirements specifying disposal methods and marking (labeling) procedures, and controlling PCB use. To assist the Department of Energy (DOE) in its efforts to comply with the TSCA statute and implementing regulations, the Office of Environmental Guidance has prepared the document ``Guidance on the Management of Polychlorinated Biphenyls (PCBs).`` That document explains the requirements specified in the statute and regulations for managing PCBs including PCB use, storage, transport, and disposal. The requirements outlined at 40 CFR 761.40 through 761.45 specify marking requirements for most PCB items (i.e., any PCB Article, PCB Container, PCB Article Container, or PCB Equipment that contains PCBs). Most PCB items require PCB marks, which are defined as a descriptive name, instructions, cautions, or other information applied to PCB Items or other objects subject to these regulations. The marking regulations include requirements for PCB marks on PCB Items, storage areas, and temporary storage areas. This Information Brief supplements the PCB guidance document by responding to common questions concerning marking requirements for PCBs. It is one of a series of Information Briefs pertinent to PCB management issues.

  19. Hypotensive acute effect of photobiomodulation therapy on hypertensive rats.

    PubMed

    Oishi, J C; De Moraes, T F; Buzinari, T C; Cárnio, E C; Parizotto, N A; Rodrigues, G J

    2017-06-01

    The purpose of this study was to evaluate the acute effect of photobiomodulation therapy (PBM) on arterial pressure in hypertensive and normotensive rats with application in an abdominal region. Normotensive (2K) and hypertensive (2K-1C) wistar rats were treated with PBM. Systolic arterial pressure (SAP), diastolic arterial pressure (DAP), mean arterial pressure (MAP) and heart rate (HR) were measured before, during and after PBM application. The nitric oxide (NO) serum concentration was measured before and after PBM application. Vascular reactivity study was performed in isolated thoracic aortas. Aluminum gallium arsenide (GaAlAs) diode laser was used, at 660nm wavelength and 100mW optical output. The PBM application induced a decrease of SAP in 2K-1C rats. In 2K rats, the PBM application had no effect on SAP, DAP and MAP. Moreover, the magnitude of hypotensive effect was higher in 2K-1C than in 2K rats. The PBM application induced a decrease of HR in 2K-1C and 2K, with higher effect in 2K-1C rats. In 2K-1C, the hypotensive effect induced by PBM was longer than that obtained in 2K rats. PBM application induced an elevation of NO concentration in serum from 2K-1C and 2K rats, with higher effect in 2K-1C. In isolated aortic rings PBM effect is dependent of NO release, and is not dependent of nitric oxide synthase (NOS) activation. Our results indicate that the abdominal acute application of PBM at 660nm is able to induce a long lasting hypotensive effect in hypertensive rats and vasodilation by a NO dependent mechanism. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Comparison between dexmedetomidine and remifentanil for controlled hypotension during tympanoplasty.

    PubMed

    Richa, F; Yazigi, A; Sleilaty, G; Yazbeck, P

    2008-05-01

    Controlled hypotension is frequently used for obtaining better exposure during tympanoplasty. The aim of this study was to compare dexmedetomidine, a selective, short-acting, central alpha2-adrenergic agonist with remifentanil, an ultra-short-acting opioid with properties similar to other mu-specific agonists, regarding their effects in achieving controlled hypotension and improving surgical field exposure and surgeon's satisfaction during tympanoplasty. In this prospective, double-blind pilot study, 24 consecutive patients scheduled for elective tympanoplasty were randomly assigned to receive either dexmedetomidine 1 microg kg(-1) over 10 min at anaesthesia induction followed by 0.4-0.8 microg kg(-1) h(-1) infusion during maintenance or remifentanil 1 microg kg(-1) over 1 min at anaesthesia induction followed by 0.2-0.4 microg kg(-1) min(-1) infusion during maintenance. Mean arterial pressure and heart rate were recorded before induction, at incision, 30, 60, 90 and 120 min after incision and 10 min after stopping the infusion. Surgical field exposure condition and satisfaction scores were assessed by the surgeon, blinded to the study drugs. Mean arterial pressure and heart rate were significantly lower in the remifentanil group compared with the dexmedetomidine group at all times (P = 0.03 and 0.036, respectively). Surgical field exposure condition (3 +/- 0.01 vs. 2.3 +/- 0.7; P = 0.039) and surgeons' satisfaction (3 +/- 0.01 vs. 2.25 +/- 0.87; P = 0.039) scores were significant after remifentanil compared with dexmedetomidine. Infusion of dexmedetomidine, at the doses used in this study, was less effective than remifentanil in achieving controlled hypotension, good surgical field exposure condition and surgeons' satisfaction during tympanoplasty.

  1. Hypotension and bradycardia associated with concomitant tizanidine and lisinopril therapy.

    PubMed

    Publow, Susan W; Branam, Donald L

    2010-10-01

    A case of severe bradycardia and hypotension associated with concomitant tizanidine and lisinopril therapy is reported. An 85-year-old man with a chief complaint of profound weakness was admitted to the hospital with a blood pressure reading of 60/32 mm Hg and a heart rate of 37 beats/min. His medical history included type 2 diabetes mellitus, congestive heart failure, gastroesophageal reflux disease, chronic obstructive pulmonary disease, osteoarthritis, restless leg syndrome, benign prostatic hyperplasia, generalized anxiety disorder with depression, and severe chronic back pain for which he was receiving treatment at a pain clinic. Two days before hospital admission, he had been seen at the pain clinic and started on ti-zanidine. Additional medications included acetaminophen, chlorpromazine, citalopram, finasteride, lidocaine patch, lisinopril, metformin, pramipexole, omeprazole, simvastatin, theophylline, diclofenac topical gel, hydrocodone-acetaminophen, and ondansetron. After taking three doses of the newly prescribed tizanidine, he developed severe hypotension and bradycardia. Notable laboratory test values included a serum creatinine concentration of 1.90 mg/dL, a blood urea nitrogen concentration of 21 mg/dL, a serum potassium concentration of 5.5 meq/L, and a serum sodium concentration of 128 meq/L. Upon admission, tizanidine, lisinopril, theophylline, omeprazole, and simvastatin were withheld, and i.v. fluids were administered. The patient's vital signs began to gradually improve. Within 24 hours, the patient's blood pressure and heart rate had improved, as had the previously abnormal laboratory test values. Tizanidine was discontinued, and all of his other preadmission medications were restarted at discharge. The addition of tizanidine in a patient receiving long-term treatment with lisinopril was associated with severe hypotension and bradycardia.

  2. Rebound intracranial hypertension: a complication of epidural blood patching for intracranial hypotension.

    PubMed

    Kranz, P G; Amrhein, T J; Gray, L

    2014-06-01

    Rebound intracranial hypertension is a complication of epidural blood patching for treatment of intracranial hypotension characterized by increased intracranial pressure, resulting in potentially severe headache, nausea, and vomiting. Because the symptoms of rebound intracranial hypertension may bear some similarity to those of intracranial hypotension and literature reports of rebound intracranial hypertension are limited, it may be mistaken for refractory intracranial hypotension, leading to inappropriate management. This clinical report of 9 patients with confirmed rebound intracranial hypertension reviews the clinical characteristics of patients with this condition, emphasizing factors that can be helpful in discriminating rebound intracranial hypertension from refractory spontaneous intracranial hypotension, and discusses treatment.

  3. Influence of endurance exercise training status and gender on postexercise hypotension.

    PubMed

    Senitko, Annette N; Charkoudian, Nisha; Halliwill, John R

    2002-06-01

    In sedentary individuals, postexercise hypotension after a single bout of aerobic exercise is due to a peripheral vasodilation. Endurance exercise training has the potential to modify this response and perhaps reduce the degree of postexercise hypotension. We tested the hypothesis that endurance exercise-trained men and women would have blunted postexercise hypotension compared with sedentary subjects but that the mechanism of hypotension would be similar (i.e., vasodilation). We studied 16 endurance-trained and 16 sedentary men and women. Arterial pressure, cardiac output, and total peripheral resistance were determined before and after a single 60-min bout of exercise at 60% peak oxygen consumption. All groups exhibited a similar degree of postexercise hypotension (approximately 4-5 mmHg; P < 0.05 vs. preexercise). In sedentary men and women, hypotension was the result of vasodilation (Deltaresistance: -8.9 +/- 2.2%). In endurance-trained women, hypotension was also the result of vasodilation (-8.1 +/- 4.1%). However, in endurance-trained men, hypotension was the result of a reduced cardiac output (-5.2 +/- 2.4%; P < 0.05 vs. all others) and vasodilation was absent (-0.7 +/- 3.3%; P < 0.05 vs. all others). Thus we conclude the magnitude of postexercise hypotension is similar in sedentary and endurance-trained men and women but that endurance-trained men and women achieve this fall in pressure via different mechanisms.

  4. Involvement of the renal kallikrein-kinin system in K(+)-induced diuresis and natriuresis in anesthetized rats.

    PubMed

    Suzuki, T; Katori, M; Fujita, T; Kumagai, Y; Majima, M

    2000-07-07

    Intravenous infusion of a high-K(+) solution (67.5 mM KCl, 67.5 mM NaCl) to anesthetized rats increased urine volume by 47.6% after 60 min, compared with infusion of a Na(+) solution (135 mM NaCl). This treatment also increased urinary excretion of Na(+) by 32.2%, in parallel with an increase in excretion of K(+) or Cl(-). Urinary excretion of kallikrein increased within 60 min after the start of K(+) infusion. A bradykinin B(2) receptor antagonist, 8-[3-[N-[(E)-3-(6-acetamidopyridin-3-yl)acryloylglycyl]-N-me thylamino ]-2,6-dichlorobenzyloxy]-2-methylquinoline (FR173657; 1.0 mg/kg, i.v. ), inhibited the K(+)-induced diuresis and natriuresis by 41.0% and 26.7%, respectively. These results indicate that K(+) load induces diuresis and natriuresis through the renal kallikrein-kinin system in rats.

  5. Pathophysiological basis of orthostatic hypotension in autonomic failure

    NASA Technical Reports Server (NTRS)

    Smit, A. A.; Halliwill, J. R.; Low, P. A.; Wieling, W.

    1999-01-01

    In patients with autonomic failure orthostatic hypotension results from an impaired capacity to increase vascular resistance during standing. This fundamental defect leads to increased downward pooling of venous blood and a consequent reduction in stroke volume and cardiac output that exaggerates the orthostatic fall in blood pressure. The location of excessive venous blood pooling has not been established so far, but present data suggest that the abdominal compartment and perhaps leg skin vasculature are the most likely candidates. To improve the orthostatic tolerance in patients with autonomic failure, protective measures that reduce excessive orthostatic blood pooling have been developed and evaluated. These measures include physical counter-manoeuvres and abdominal compression.

  6. The Management of Orthostatic Hypotension in Parkinson’s Disease

    PubMed Central

    Sánchez-Ferro, Álvaro; Benito-León, Julián; Gómez-Esteban, Juan Carlos

    2013-01-01

    Orthostatic hypotension (OH) is a common and disabling symptom affecting Parkinson’s disease (PD) patients. We present the effect of the different therapies commonly used to manage PD on this clinical manifestation. For this purpose, we describe the relationship between OH and the current treatments employed in PD, such as L-DOPA, dopaminergic agonists, and continuous dopaminergic stimulation therapies. Additionally, we review the therapeutic measures that could be used to ameliorate OH. There are different approaches to deal with this manifestation, including pharmacological and non-pharmacological treatments, although none of them is specifically aimed for treating OH in PD. PMID:23772219

  7. Early experiences of vasodilators and hypotensive anesthesia in children.

    PubMed

    Brown, T C K

    2012-07-01

    The physiological application of OHMS LAW explains the basis of hypotensive anesthesia. V = IR translates into: Pressure = Flow × Resistance or Blood pressure = Cardiac Output × Peripheral Resistance. If peripheral resistance is reduced by a vasodilator such as sodium nitroprusside (a short acting, vascular smooth muscle relaxant) or phenoxybenzamine (a long acting α adrenoreceptor antagonist), blood pressure will fall and vasoconstriction and bleeding will be reduced. A less desirable alternative to lowering blood pressure could be to reduce cardiac output by suppressing myocardial contractility using a ß(1) adrenoceptor antagonist or an inhalational agent such as isoflurane.

  8. Spontaneous Intracranial Hypotension Associated with Kinetic Tremor and Ataxia

    PubMed Central

    Salazar, Richard

    2016-01-01

    Background Spontaneous intracranial hypotension (SIH) is a clinically variable syndrome caused by low cerebrospinal fluid (CSF) pressure due to a non-traumatic CSF leak. Phenomenology Shown This case describes a 68-year-old gentleman who presents with chronic and slightly progressive kinetic tremor of bilateral hands associated with gait ataxia and gait start hesitation. Educational Value This case underscores the importance of having a high index of suspicion for the diagnosis of SIH when encountering a patient presenting with late-onset progressive kinetic tremor and gait ataxia syndrome. PMID:27351232

  9. [Case of spontaneous intracranial hypotension associated with depressed consciousness].

    PubMed

    Kato, Takahiro; Nakagawa, Itsuo; Hidaka, Shozo; Okada, Yasunori; Kubo, Takashi; Okamura, Kenta

    2007-04-01

    We experienced a case of spontaneous intracranial hypotension (SIH) complicated with depressed consciousness after its treatment. A 56-year-old woman developed postural headache, and her MRI revealed bilateral chronic subdural hematoma (CSH). After treatment with epidural autolongous blood patch, her headache resolved completely. However, two days after, the patient developed depressed conciousness, and MRI showed brain sagging and downward brain displacement. After management with conservative treatment, including second epidural blood patch and hematoma drainage, the patient became alert and other symptoms resolved gradually. We demonstrated that caution should be taken for the management of SIH, especially in the case associated with CSH.

  10. Spontaneous Intracranial Hypotension: An Etiology for Consciousness Disorder and Coma.

    PubMed

    Collange, Olivier; Wolff, Valérie; Cebula, Hélène; Pradignac, Alain; Meyer, Alain; Kindo, Michel; Diemunsch, Pierre; Proust, François; Mertes, Paul-Michel; Kremer, Stéphane

    2016-11-15

    We report 3 cases of spontaneous intracranial hypotension (SIH) associated with consciousness disorder and coma. In patients, SIH was suspected on a computed tomography scan and diagnosed by cerebral magnetic resonance imaging (MRI). Spinal MRI confirmed cerebrospinal fluid leakage. SIH should be seen as an underestimated cause of consciousness disorder and coma, especially in patients with a history of orthostatic headache, spinal injury, or oculomotor signs. Computed tomography scans should be examined for signs of SIH before operating on patients with a spontaneous subdural hematoma. Brain and spine MRI should be performed when SIH is suspected. Our 3 patients have shown good recovery without any neurological sequelae.

  11. Hypotensive akathisia: autonomic failure associated with leg fidgeting while sitting.

    PubMed

    Cheshire, W P

    2000-12-26

    The author describes a distinct clinical syndrome in six patients with autonomic failure who manifested habitual, voluntary, transiently suppressible, yet irresistible leg movements occurring only in the sitting position. Keeping the legs still brought on vague symptoms of fatigue, lightheadedness, or apprehension. Repetitive leg crossing, muscle tensing, foot twirling or wiggling, or heel or toe floor tapping while sitting may have compensated for orthostatic hypotension and raised systolic blood pressure by a mean of 28 mm Hg and diastolic pressure by a mean of 11 mm Hg.

  12. [Effects of octreotide on experimental orthostatic neurogenic hypotension].

    PubMed

    Verwaerde, P; Bordet, R; Portolan, G; Tran, M A; Marques, M A; Montastruc, J L; Sénard, J M

    1996-08-01

    The synthetic somatostatin analogue, octreotide, has recently been proposed for the treatment of both postprandial and orthostatic hypotension (OH) in humans with autonomic failure related to multiple system atrophy (MSA) or diabetes mellitus. However, pharmacodynamic data are not still available in experimental models of orthostatic hypotension. We investigated in a model of neurogenic orthostatic hypotension, obtained by chronic sinoaortic denervation (SAD) in chloralose-anaesthetized dogs, the effects of octreotide (0.1 mg/kg, subcutaneous route) during a double-blind cross-over study vs placebo. Blood pressure (BP) and heart rate (HR) average values, SBP and HR short-term variabilities (using fast Fourier transformation) in both low (LF: 50-150 mHz) and high frequency range (respiratory rate +/- 50 mHz) and plasma noradrenaline (NA) levels (HPLC) were measured in supine position and during head-up tilt test (HUT: 80 degrees, 10 min) before and 45 min after drug administration. In controls, as expected, head-up tilt test induced a significant increase in DBP (+14 +/- 8 mmHg), HR (+36 +/- 21 beat/min), NA (296 +/- 118 vs 141 +/- 63 pg/ml), SBP-LF (25 +/- 5 vs 14 +/- 3%) whereas HR-HF significantly decreased. The changes during head-up tilt test were not modified after placebo or octreotide administration. In SAD dogs, head-up tilt test elicited a dramatic fall in SBP (-74 +/- 39 mmHg), DBP (-20 +/- 15 mmHg) without any significant change in HR (-5 +/- 12 beat/min), NA (708 +/- 213 vs 606 +/- 331 pg/ml), SBP-LF (16 +/- 3 vs 16 +/- 3%), HR-HF (8 +/- 2 vs 7 +/- 1%). Octreotide or placebo failed to significantly modify any of the measured parameters during head-up tilt test performed 45 min after drug administration. At the dose used, octreotide elicited a 80% decrease in insulin plasma levels after 45 min in both normal and SAD dogs. These results suggest that 1) this experimental model of orthostatic hypotension in SAD dogs is reproductible and can be used to

  13. A Reversible Cause of Skin Hyperpigmentation and Postural Hypotension

    PubMed Central

    Husain, Mehreen; Madduri, Sujay; Okolie, Pamela; Nunlee-Bland, Gail; Williams, James

    2013-01-01

    Vitamin B12 deficiency results in neuropsychiatric, hematologic, gynecologic, cardiovascular, and cutaneous manifestations. It is seen most commonly in the elderly, malabsorption diseases  (>60% of all cases), vegans, and vegetarians. Manifestations of pernicious anemia may be similar to Addison disease and may lead to a misdiagnosis. Herein, we report two cases of vitamin B12 deficiency in which clinical features shared many similarities with Addison disease. Both patients presented with progressive darkening of hands and postural hypotension that reversed with replenishment of vitamin B12. Vitamin B12 deficiency should be considered in patients presenting with skin lesions especially with other coexisting autoimmune diseases. PMID:23840983

  14. Alpha-adrenoceptor antagonists and chemical sympathectomy exacerbate anaphylaxis-induced hypotension, but not portal hypertension, in anesthetized rats.

    PubMed

    Wang, Mofei; Tanida, Mamoru; Shibamoto, Toshishige; Kurata, Yasutaka

    2013-10-15

    Anaphylactic shock is sometimes life-threatening, and it is accompanied by hepatic venoconstriction in animals, which, in part, accounts for anaphylactic hypotension. Roles of norepinephrine and α-adrenoceptor in anaphylaxis-induced hypotension and portal hypertension were investigated in anesthetized ovalbumin-sensitized Sprague-Dawley rats. The sensitized rats were randomly allocated to the following pretreatment groups (n = 6/group): 1) control (nonpretreatment), 2) α1-adrenoceptor antagonist prazosin, 3) nonselective α-adrenoceptor antagonist phentolamine, 4) 6-hydroxydopamine-induced chemical sympathectomy, and 5) surgical hepatic sympathectomy. Anaphylactic shock was induced by an intravenous injection of the antigen. The systemic arterial pressure (SAP), central venous pressure (CVP), portal venous pressure (PVP), and portal venous blood flow (PBF) were measured, and splanchnic [Rspl: (SAP-PVP)/PBF] and portal venous [Rpv: (PVP-CVP)/PBF] resistances were determined. Separately, we measured efferent hepatic sympathetic nerve activity during anaphylaxis. In the control group, SAP markedly decreased, followed by a gradual recovery toward baseline. PVP and Rpv increased 3.2- and 23.3-fold, respectively, after antigen. Rspl decreased immediately, but only transiently, after antigen, and then increased 1.5-fold later than 10 min. The α-adrenoceptor antagonist pretreatment or chemical sympathectomy inhibited the late increase in Rspl and the SAP recovery. Pretreatment with α-adrenoceptor antagonists, or either chemical or surgical hepatic sympathectomy, did not affect the antigen-induced increase in Rpv. Hepatic sympathetic nerve activity did not significantly change after antigen. In conclusion, α-adrenoceptor antagonists and chemical sympathectomy exacerbate anaphylaxis-induced hypotension, but not portal hypertension, in anesthetized rats. Hepatic sympathetic nerves are not involved in anaphylactic portal hypertension.

  15. Teaching with Mark Dion

    ERIC Educational Resources Information Center

    Fusaro, Joe

    2011-01-01

    Mark Dion creates sculptures, installations, and interactive environments that sometimes seem contrary to what one expects from visual artists. Remarkable curiosity cabinets and carefully arranged artifacts from specific places and time periods make up a large part of his work. His work does not neatly fit into traditional lessons about elements…

  16. Double Marking Revisited

    ERIC Educational Resources Information Center

    Brooks, Val

    2004-01-01

    In 2002, the Qualifications and Curriculum Authority (QCA) published the report of an independent panel of experts into maintaining standards at Advanced Level (A-Level). One of its recommendations was for: limited experimental double marking of scripts in subjects such as English to determine whether the strategy would significantly reduce errors…

  17. Airbag bounce marks

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Looking east from the lander, the last few bounce marks as Pathfinder rolled to a stop on July 4 are visible in the soil in this image, taken by the Imager for Mars Pathfinder (IMP). The two most distant marks, identified by pointers in the image, consist of dark patches of disturbed soil. The three closest marks are clearly visible in the foreground, with one easily identifiable behind the Atmospheric Structure Instrument/Meteorology Package (ASI/MET) mast, is at right. The most distant positively identified bounce mark, indicated by the pointer at right, is approximately 11.3 meters (37 feet) from the lander.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator. JPL is an operating division of the California Institute of Technology (Caltech).

  18. Teaching with Mark Dion

    ERIC Educational Resources Information Center

    Fusaro, Joe

    2011-01-01

    Mark Dion creates sculptures, installations, and interactive environments that sometimes seem contrary to what one expects from visual artists. Remarkable curiosity cabinets and carefully arranged artifacts from specific places and time periods make up a large part of his work. His work does not neatly fit into traditional lessons about elements…

  19. Digitally Marking RSA Moduli

    SciTech Connect

    Johnston, A.M.

    2000-10-09

    The moduli used in RSA (see [5]) can be generated by many different sources. The generator of that modulus (assuming a single entity generates the modulus) knows its factorization. They would have the ability to forge signatures or break any system based on this moduli. If a moduli and the RSA parameters associated with it were generated by a reputable source, the system would have higher value than if the parameters were generated by an unknown entity. So for tracking, security, confidence and financial reasons it would be beneficial to know who the generator of the RSA modulus was. This is where digital marking comes in. An RSA modulus ia digitally marked, or digitally trade marked, if the generator and other identifying features of the modulus (such as its intended user, the version number, etc.) can be identified and possibly verified by the modulus itself. The basic concept of digitally marking an RSA modulus would be to fix the upper bits of the modulus to this tag. Thus anyone who sees the public modulus can tell who generated the modulus and who the generator believes the intended user/owner of the modulus is.

  20. Little Jiffy, Mark IV

    ERIC Educational Resources Information Center

    Kaiser, Henry F.; Rice, John

    1974-01-01

    In this paper three changes and one new development for the method of exploratory factor analysis (a second generation Little Jiffy) developed by Kaiser are described. Following this short description a step-by-step computer algorithm of the revised method, dubbed Little Jiffy, Mark IV is presented. (MP)

  1. Marking Advanced Essays

    ERIC Educational Resources Information Center

    Donley, Michael

    1978-01-01

    A list of points to aid essay writers is suggested as the basis of a marking system for the teacher of English as a foreign language. The checklist, obtained from a book on higher education by Ruth Beard, can be adapted to the English as a foreign language situation. (SW)

  2. Fathoming Mark Twain.

    ERIC Educational Resources Information Center

    Biggar, Joanna

    1988-01-01

    Relates the efforts of completing two collections of the works and papers of Mark Twain. Describes the combined efforts of the University of Iowa and the University of California to publish both a scholarly edition and a reader's edition devoted to Twain. (KO)

  3. Curiosity Leaves Its Mark

    NASA Image and Video Library

    2012-08-29

    This image shows a close-up of track marks from the first test drive of NASA Curiosity rover. The rover arm is visible in the foreground. A close inspection of the tracks reveals a unique, repeating pattern: Morse code for JPL.

  4. Interview with Mark Ashwill

    ERIC Educational Resources Information Center

    Landsberger, Joe

    2006-01-01

    This article presents an interview with Mark Ashwill, Director of the Institute of International Education-Vietnam in Ha Noi, Vietnam, a branch of the Institute of International Education (IIE). In this interview, Ashwill talks about his work as Director of the Institute of International Education-Vietnam, the role that communications technology…

  5. Rehab Mark. Trainer's Guide.

    ERIC Educational Resources Information Center

    Greenwood, Reed; And Others

    This manual is written for trainers working in the RehabMark system of employer development in vocational rehabilitation services. Videotapes are available to accompany lectures and other training activities, and materials for transparencies are provided in an appendix. After an introductory chapter, the first half of the manual contains training…

  6. Rehab Mark. Participant's Workbook.

    ERIC Educational Resources Information Center

    Greenwood, Reed; And Others

    This manual is the employer-focused component workbook of a vocational rehabilitation program. Goals of the RehabMark approach include increased exposure of the rehabilitation agency in the local community, expanded contributions by the agency to community members, and services benefiting numerous clients simultaneously. The first half of the…

  7. Interview with Mark Ashwill

    ERIC Educational Resources Information Center

    Landsberger, Joe

    2006-01-01

    This article presents an interview with Mark Ashwill, Director of the Institute of International Education-Vietnam in Ha Noi, Vietnam, a branch of the Institute of International Education (IIE). In this interview, Ashwill talks about his work as Director of the Institute of International Education-Vietnam, the role that communications technology…

  8. Ultrawide-band electromagnetic pulses induced hypotension in rats.

    PubMed

    Lu, S T; Mathur, S P; Akyel, Y; Lee, J C

    The ultrawide-band (UWB) electromagnetic pulses are used as a new modality in radar technology. Biological effects of extremely high peak E-field, fast rise time, ultrashort pulse width, and ultrawide band have not been investigated heretofore due to the lack of animal exposure facilities. A new biological effects database is needed to establish personnel protection guidelines for these new type of radiofrequency radiation. Functional indices of the cardiovascular system (heart rate, systolic, mean, and diastolic pressures) were selected to represent biological end points that may be susceptible to the UWB radiation. A noninvasive tail-cuff photoelectric sensor sphygmomanometer was used. Male Wistar-Kyoto rats were subjected to sham exposure, 0.5-kHz (93 kV/m, 180 ps rise time, 1.00 ns pulse width, whole-body averaged specific absorption rate, SAR = 70 mW/kg) or a 1-kHz (85 kV/m, 200 ps rise time, 1.03 ns pulse width, SAR = 121 mW/kg) UWB fields in a tapered parallel plate GTEM cell for 6 min. Cardiovascular functions were evaluated from 45 min to 4 weeks after exposures. Significant decrease in arterial blood pressures (hypotension) was found. In contrast, heart rate was not altered by these exposures. The UWB radiation-induced hypotension was a robust, consistent, and persistent effect.

  9. Ultrawide-band electromagnetic pulses induced hypotension in rats.

    PubMed

    Lu, S T; Mathur, S P; Akyel, Y; Lee, J C

    1999-09-01

    The ultrawide-band (UWB) electromagnetic pulses are used as a new modality in radar technology. Biological effects of extremely high peak E-field, fast rise time, ultrashort pulse width, and ultrawide band have not been investigated heretofore due to the lack of animal exposure facilities. A new biological effects database is needed to establish personnel protection guidelines for these new type of radiofrequency radiation. Functional indices of the cardiovascular system (heart rate, systolic, mean, and diastolic pressures) were selected to represent biological end points that may be susceptible to the UWB radiation. A noninvasive tail-cuff photoelectric sensor sphygmomanometer was used. Male Wistar-Kyoto rats were subjected to sham exposure, 0.5-kHz (93 kV/m, 180 ps rise time, 1.00 ns pulse width, whole-body averaged specific absorption rate, SAR = 70 mW/kg) or a 1-kHz (85 kV/m, 200 ps rise time, 1.03 ns pulse width, SAR = 121 mW/kg) UWB fields in a tapered parallel plate GTEM cell for 6 min. Cardiovascular functions were evaluated from 45 min to 4 weeks after exposures. Significant decrease in arterial blood pressures (hypotension) was found. In contrast, heart rate was not altered by these exposures. The UWB radiation-induced hypotension was a robust, consistent, and persistent effect.

  10. Mechanisms of orthostatic hypotension and tachycardia in patients with pheochromocytoma.

    PubMed

    Streeten, D H; Anderson, G H

    1996-08-01

    We have explored the pathophysiological mechanisms of orthostatic hypotension and orthostatic tachycardia, found to be present in 83% and 61% respectively of 18 patients with subsequently proven pheochromocytoma. Orthostatic increases in plasma norepinephrine (NE) concentrations were significantly greater in the patients than in normal control subjects. Intravenous infusions of NE at 1, 2, 4, 8, and 16 micrograms/min induced similar increases in plasma NE levels but smaller increments in systolic and diastolic BP in the pheochromocytoma patients than in normal control subjects. This was reflected by a significantly greater increment in plasma NE concentration required to raise systolic BP by 15 mm Hg and diastolic BP by 7 mm Hg in the pheochromocytoma patients than in the normal subjects (P < .05 and P < .01, respectively). Measurements of venous contractile responses to locally infused NE by the dorsal hand vein (LVDT) technique revealed significantly reduced slopes of the regressions of log NE infusion rate on change in venous diameter in the pheochromocytoma patients compared with normal subjects. The results indicate reduced responsiveness of the vasculature to NE in patients with pheochromocytoma, probably due to down-regulation of alpha-adrenergic receptors resulting from persistent elevation of the physiological agonist NE. This was shown by other authors to be present in circulating platelets. The pathophysiological importance of the subnormal venous responses to the orthostatic hypotension and tachycardia in the patients were supported by the finding that the orthostatic changes were corrected by lower body compression to 45 mm Hg with a MAST pressure suit.

  11. [Intermittent focal cerebral ischemia in hypotension due to pacemaker syndrome].

    PubMed

    Hagendorff, A; Pizzulli, L; Dettmers, C; Block, A; Omran, H; Hartmann, A; Manz, M; Lüderitz, B

    1994-12-01

    A pacemaker syndrome manifested as transient sensoric aphasia in a 68-year-old woman with a VVI-pace-maker implanted after SA-block. The attack occurred during long-term blood pressure recording and Holter monitoring. Borderline hypotension was documented during ventricular pacing which induced a retrograde excitation of the atrium. Clinical investigations excluded any intracranial abnormality, any source of embolism or stenosis of extra- and intracranial cerebral arteries. Cerebral blood flow measurements revealed a significant increase during pacing at elevated heart rate. Therefore, a device for AV-sequential pacing was implanted and basic pacing rate was elevated. The present case report indicates that focal and not only global cerebral ischemia can be produced by an impairment of systemic hemodynamics due to hypotension and a pacemaker syndrome. Improvement of cerebral blood flow during pacing is an unexpected finding contrasting with the concept of autoregulation. In addition, pacemaker implantation should be discussed in patients with transient cerebral perfusion deficits if an improvement of cerebral blood flow is documented along with rising heart rate.

  12. Phenotyping Hypotensive Patients in Critical Care Using Hospital Discharge Summaries

    PubMed Central

    Dai, Yang; Lokhandwala, Sharukh; Long, William; Mark, Roger; Lehman, Li-wei H.

    2017-01-01

    Among critically-ill patients, hypotension represents a failure in compensatory mechanisms and may lead to organ hypoperfusion and failure. In this work, we adopt a data-driven approach for phenotype discovery and visualization of patient similarity and cohort structure in the intensive care unit (ICU). We used Hierarchical Dirichlet Process (HDP) as a nonparametric topic modeling technique to automatically learn a d-dimensional feature representation of patients that captures the latent “topic” structure of diseases, symptoms, medications, and findings documented in hospital discharge summaries. We then used the t-Distributed Stochastic Neighbor Embedding (t-SNE) algorithm to convert the d-dimensional latent structure learned from HDP into a matrix of pairwise similarities for visualizing patient similarity and cohort structure. Using discharge summaries of a large patient cohort from the MIMIC II database, we evaluated the clinical utility of the discovered topic structure in phenotyping critically-ill patients who experienced hypotensive episodes. Our results indicate that the approach is able to reveal clinically interpretable clustering structure within our cohort and may potentially provide valuable insights to better understand the association between disease phenotypes and outcomes. PMID:28630951

  13. Injury patterns associated with hypotension in pediatric trauma patients: A national trauma database review.

    PubMed

    Gardner, Alison R; Diz, Debra I; Tooze, Janet A; Miller, Chadwick D; Petty, John

    2015-06-01

    Hypotension after trauma is most commonly assumed to be hemorrhagic, or hypovolemic, in origin. However, hypotension may occur in pediatric patients with isolated head injury, challenging accepted tenets of trauma care. We sought to quantify the contribution of head injury to the development of hypotension after pediatric trauma. This is a retrospective cohort analysis using the National Trauma Data Bank registry 2009. Children aged 0 to 15 years were classified by injury pattern sustained during trauma using discharge diagnosis International Classification of Diseases, Ninth Revision, codes into isolated head, hemorrhagic, spinal cord, or other injury type. The primary outcome was hypotension for age at arrival to the emergency department. Risk of hypotension was estimated and compared by injury pattern using absolute and relative risks (RRs) stratified by age group (0-4 years, 5-11 years, 12-15 years). Rates of hypotension ranged from 1.8% to 2.3% by age, with the highest incidence in the 12- to 15-year group. The RR of hypotension from isolated head injury (RR, 2.5; 95% confidence interval, 2.0-3.2 vs. other) was not significantly different from the RR for hemorrhagic injury (RR, 2.7; 95% confidence interval, 2.1-3.5 vs. other) in the 0- to 4-year-old group. For the older age groups, the RR of hypotension from isolated head injury was significantly lower than from hemorrhagic injury. Hypotension occurs after isolated head injury in children, and the risk of hypotension is as great as hemorrhagic injuries in children aged 0 to 4 years. This finding should now lead us to confirm whether a cause-effect relationship exists and, if so, isolate the responsible mechanism. In turn, this could reveal an opportunity to tailor treatments to address the underlying mechanism for hypotension in these children. Prognostic and epidemiologic study, level III.

  14. Mark Twain on phrenology.

    PubMed

    Stone, James L

    2003-12-01

    Mark Twain was a noted 19th century American writer and humorist. He often elaborated upon the personalities of his characters, and his observational skills reflected a strong interest in psychology. Similarly, he found an interest in phrenology, a pseudoscience that purported to characterize personality traits according to elevations or depressions on the head. Twain's style is clearly reflected in the interesting essay he wrote regarding his personal experience with phrenology.

  15. Obstruction Marking and Lighting

    DTIC Science & Technology

    1962-09-01

    Overhead Wires. Markers displayed on overhead wires should be spherical in shape with a diameter of not less than 20 incites, or may be of another shape...150 feet, or fraction thereof, of the overall length of the overhead line. These markers should be placed at equal intervals not more than 150 feet...obstructions by "colors." The distance between mark- ers on overhead wires located more than 15,000 feet from the refer- ence point of any landing area

  16. Body water handling in response to hypertonic-saline induced diuresis in fasting northern elephant seal pups (Mirounga angustirostris)

    NASA Technical Reports Server (NTRS)

    Ortiz, Rudy M.; Wade, Charles E.; Ortiz, C. Leo

    2003-01-01

    During natural fasting conditions in postweaned northern elephant seal (NES) (Mirounga angustirostris) pups, urinary water loss is minimized and percent total body water (TBW) is maintained constant. However, following infusion of hypertonic saline, glomerular filtration rate (GFR) and urine output increased in fasting pups. Therefore, we quantified the magnitude of the hypernatremia-induced diuresis relative to the animal's total body water (TBW) pool and the percentage of filtered water reabsorbed. Following a 24 h control period, naturally fasting NES pups (n=7) were infused (4 ml min(-1)) with hypertonic saline (16.7%) at a dose of 3 mmol NaCl kg(-1) body mass. Total body water was estimated prior to infusion by tritium dilution, GFR was estimated by standard creatinine clearance, and urine output (V) was measured for 24 h during the control and post infusion periods. Percentage of filtered water reabsorbed was calculated as (1-(V/GFR))x100. Twenty-four hours following the infusion, GFR (control: 69+/-12 ml min(-1) and post-infusion: 118+/-19 ml min(-1); mean+/-S.E.) increased 77+/-28% above control and the percentage of filtered water reabsorbed was decreased 0.4+/-0.1%. The increase in urine output (control: 218+/-47 ml d(-1) and post-infusion: 883+/-92 ml d(-1)) accounted for 1.7+/-0.2% of the pups' TBW. The hypernatremia-induced diuresis was accompanied by the loss of body water indicating the lack of water retention. Although the 77% increase in GFR was only associated with a 0.4% decrease in the percentage of filtered water reabsorbed, this decrease was significant enough to result in a 4-fold increase in urine output. Despite the observed diuresis, fasting NES pups appear to possess an efficient water recycling mechanism requiring only a small percentage of body water to excrete an excess salt load. This water recycling mechanism may allow pups to avoid negative perturbations in body water as they initiate feeding in a marine environment following the

  17. Postobstructive diuresis in cats with naturally occurring lower urinary tract obstruction: incidence, severity and association with laboratory parameters on admission.

    PubMed

    Fröhlich, Laura; Hartmann, Katrin; Sautter-Louis, Carola; Dorsch, Roswitha

    2016-10-01

    The objectives of this retrospective study were to investigate the actual incidence of postobstructive diuresis after relief of urethral obstruction in cats, as well as to identify changes in blood and urine parameters that might be associated with postobstructive diuresis (POD), and to assess the impact of fluid therapy. The medical records of 57 male cats with urethral obstruction that were treated with an indwelling urinary catheter were retrospectively analysed. Absolute urine output in ml/kg/h every 4 h and the incidence of cats with polyuria (urine volume >2 ml/kg/h) at any time point over a 48 h period after the re-establishment of urine flow were investigated. In addition, postobstructive diuresis in relation to fluid therapy (PODFR) was defined as urine output greater than the administered amount of intravenous fluids on at least two subsequent time points. Polyuria and PODFR were investigated for their association with blood and urine laboratory parameters. After 4 h, 74.1% (40/54) of the cats had polyuria, with a urine output of >2 ml/kg/h. Metabolic acidosis was present in 46.2% of the cats. Venous blood pH and bicarbonate were inversely correlated with urine output in ml/kg/h after 4 h. The overall incidence of POD within 48 h of catheterisation was 87.7%. There was a significant correlation between intravenous fluid rate at time point x and urine output at time point x + 1 at all the time points except for the fluid rate at time point 0 and the urine output after 4 h. PODFR was seen in 21/57 cats (36.8%). POD is a frequent finding in cats treated for urethral obstruction, and can be very pronounced. Further studies are required to determine whether or not a change in venous blood pH actually interferes with renal concentrating ability. The discrepancy between the frequency of cats with polyuria and PODFR (87.7% vs 36.8%) in the present study indicates that administered intravenous fluid therapy might be the driving force for the high incidence of

  18. Body water handling in response to hypertonic-saline induced diuresis in fasting northern elephant seal pups (Mirounga angustirostris)

    NASA Technical Reports Server (NTRS)

    Ortiz, Rudy M.; Wade, Charles E.; Ortiz, C. Leo

    2003-01-01

    During natural fasting conditions in postweaned northern elephant seal (NES) (Mirounga angustirostris) pups, urinary water loss is minimized and percent total body water (TBW) is maintained constant. However, following infusion of hypertonic saline, glomerular filtration rate (GFR) and urine output increased in fasting pups. Therefore, we quantified the magnitude of the hypernatremia-induced diuresis relative to the animal's total body water (TBW) pool and the percentage of filtered water reabsorbed. Following a 24 h control period, naturally fasting NES pups (n=7) were infused (4 ml min(-1)) with hypertonic saline (16.7%) at a dose of 3 mmol NaCl kg(-1) body mass. Total body water was estimated prior to infusion by tritium dilution, GFR was estimated by standard creatinine clearance, and urine output (V) was measured for 24 h during the control and post infusion periods. Percentage of filtered water reabsorbed was calculated as (1-(V/GFR))x100. Twenty-four hours following the infusion, GFR (control: 69+/-12 ml min(-1) and post-infusion: 118+/-19 ml min(-1); mean+/-S.E.) increased 77+/-28% above control and the percentage of filtered water reabsorbed was decreased 0.4+/-0.1%. The increase in urine output (control: 218+/-47 ml d(-1) and post-infusion: 883+/-92 ml d(-1)) accounted for 1.7+/-0.2% of the pups' TBW. The hypernatremia-induced diuresis was accompanied by the loss of body water indicating the lack of water retention. Although the 77% increase in GFR was only associated with a 0.4% decrease in the percentage of filtered water reabsorbed, this decrease was significant enough to result in a 4-fold increase in urine output. Despite the observed diuresis, fasting NES pups appear to possess an efficient water recycling mechanism requiring only a small percentage of body water to excrete an excess salt load. This water recycling mechanism may allow pups to avoid negative perturbations in body water as they initiate feeding in a marine environment following the

  19. Regional changes in the extravasation of albumin in the canine kidney: comparison of bradykinin and water diuresis.

    PubMed

    Lortie, M; Sirois, M G; Regoli, D; Couture, R; Adam, A; Plante, G E

    1994-11-01

    This report describes the adaptation of the albumin bound Evans blue dye (EB) extraction technique and its use in identifying regional changes in albumin extravasation rates. We present data to justify our technical approach and highlight the use of this method by describing differences resulting from two different models of induced diuresis and natriuresis. Results observed under control conditions (Group 1) are compared to those obtained following the infusion of bradykinin (BK) into the left kidney (Group 2) or hypotonic saline-induced water diuresis (Group 3). EB and water content of tissue samples of cortex (CTX), outer medulla (OM), inner medulla (IM), and papilla (PAP) regions are reported. Under control conditions a significant heterogeneous distribution of EB and water content (wet/dry tissue weight) between zones was observed. Left kidney EB values for the CTX, OM, IM, and PAP in Group 1 were 125 +/- 11, 398 +/- 56, 763 +/- 51, and 741 +/- 52 micrograms EB/g dry tissue and respective wet/dry tissue ratios were 4.48 +/- 0.05, 5.10 +/- 0.19, 7.13 +/- 0.37, and 6.35 +/- 0.32. In Group 2, BK caused a selective increase in cortex EB content to 201 +/- 7 (P < 0.01) micrograms EB/g dry tissue, without altering water content values. Results of EB extraction in Group 3 revealed no change in the CTX but significant increases in the OM, IM, and PAP regions: 576 +/- 40 (P < 0.01), 910 +/- 60 (P < 0.01), and 850 +/- 69 (P < 0.05) micrograms EB/g dry tissue, respectively. Likewise, tissue water content values were unchanged in the CTX but significantly greater in the OM, IM, and PAP: 6.02 +/- 0.22, 8.90 +/- 0.25, and 8.40 +/- 0.17, respectively (P < 0.01, all three values). This technique clearly shows the regional heterogeneity of the renal microvascular network and allows the localization of intrarenal changes in albumin extravasation. This method provides evidence that BK increases albumin extravasation in the cortex only and that changes in the renal medulla are

  20. Reply to: Spontaneous Intracranial Hypotension and its Association with Movement Disorders?

    PubMed Central

    Salazar, Richard

    2016-01-01

    In Response To: Onder H. Spontaneous intracranial hypotension and its association with movement disorders? Tremor Other Hyperkinet Mov. 2016; 6. doi: 10.7916/D84B31NS Original Article: Salazar R. Spontaneous intracranial hypotension associated with kinetic tremor and ataxia. Tremor Other Hyperkinet Mov. 2016; 6. doi: 10.7916/D8HQ3ZN5 PMID:27905574

  1. Cortical blood flow in controlled hypotension as measured by thermal diffusion 1

    PubMed Central

    Carter, L. Philip; Atkinson, James R.

    1973-01-01

    A thermal diffusion flow probe which gave a continuous, dynamic, quantitative record of cortical blood flow (CBF) was used to assess CBF in experimental animals with controlled hypotension. Acute hypotension was produced by trimethaphan camsylate, halothane, and sodium nitroprusside. Halothane produced less reduction in CBF per drop in blood pressure than the other two agents. Images PMID:4772724

  2. Surgical treatment of cervical disc protrusion causing intracranial hypotension following chiropractic manipulation.

    PubMed

    Wilson, David; Steel, Timothy; Sutton, Ian

    2015-09-01

    We describe a woman with intracranial hypotension provoked by a combination of calcified disc protrusion and chiropractic manipulation who required surgical intervention for definitive treatment. Intracranial hypotension is a rare but increasingly well recognized cause of orthostatic headache that arises due to spinal cerebrospinal fluid leakage from meningeal diverticula or dural perforations.

  3. Defining hypotension in anesthetized infants by individual awake blood pressure values: a prospective observational study.

    PubMed

    Weber, Frank; Koning, Laurens; Scoones, Gail P

    2017-04-01

    Blood pressure (BP) is the most commonly applied clinical surrogate parameter for tissue perfusion and cerebral autoregulation. Hypotension during anesthesia may contribute to unfavorable outcome in young children. Hypotension in anesthetized infants can be defined using BP values relative to individual awake baseline or absolute BP values. The aim of this study was to investigate the applicability of the two definitions and to compare the incidences of hypotension. This was a prospective observational study in 151 infants <12 months of age. The percentage of successful awake BP measurements was calculated and related to the infant's behavioral state. Hypotension under sevoflurane anesthesia was defined by a decrease of mean arterial pressure (MAP) relative to awake baseline (>20% in infants <6 months, >40% in infants >6 months) or absolute MAP values (<35 mmHg in infants <6 months, <43 mmHg in infants >6 months). The incidences of hypotension using the two definitions were compared. Awake BP values were obtained in 85% of the patients. Calm patients were more likely to allow their BP to be measured than anxious patients. Anxious patients had higher preinduction MAP values than calm patients. The relative BP approach resulted in a higher incidence of postinduction hypotension than using absolute BP values. Awake BP values were unobtainable in 15% of our patients, resulting in the necessity to define hypotension under anesthesia using absolute BP values. Definitions of hypotension using either absolute MAP or values relative to awake baseline are not interchangeable. © 2017 John Wiley & Sons Ltd.

  4. Meropenem population pharmacokinetics in critically ill patients with septic shock and continuous renal replacement therapy: influence of residual diuresis on dose requirements.

    PubMed

    Ulldemolins, Marta; Soy, Dolors; Llaurado-Serra, Mireia; Vaquer, Sergi; Castro, Pedro; Rodríguez, Alejandro H; Pontes, Caridad; Calvo, Gonzalo; Torres, Antoni; Martín-Loeches, Ignacio

    2015-09-01

    Meropenem dosing in critically ill patients with septic shock and continuous renal replacement therapy (CRRT) is complex, with the recommended maintenance doses being 500 mg to 1,000 mg every 8 h (q8h) to every 12 h. This multicenter study aimed to describe the pharmacokinetics (PKs) of meropenem in this population to identify the sources of PK variability and to evaluate different dosing regimens to develop recommendations based on clinical parameters. Thirty patients with septic shock and CRRT receiving meropenem were enrolled (153 plasma samples were tested). A population PK model was developed with data from 24 patients and subsequently validated with data from 6 patients using NONMEM software (v.7.3). The final model was characterized by CL = 3.68 + 0.22 · (residual diuresis/100) and V = 33.00 · (weight/73)(2.07), where CL is total body clearance (in liters per hour), residual diuresis is the volume of residual diuresis (in milliliters per 24 h), and V is the apparent volume of distribution (in liters). CRRT intensity was not identified to be a CL modifier. Monte Carlo simulations showed that to maintain concentrations of the unbound fraction (fu ) of drug above the MIC of the bacteria for 40% of dosing interval T (referred to as 40% of the ƒ uT >MIC), a meropenem dose of 500 mg q8h as a bolus over 30 min would be sufficient regardless of the residual diuresis. If 100% of the ƒ uT >MIC was chosen as the target, oligoanuric patients would require 500 mg q8h as a bolus over 30 min for the treatment of susceptible bacteria (MIC < 2 mg/liter), while patients with preserved diuresis would require the same dose given as an infusion over 3 h. If bacteria with MICs close to the resistance breakpoint (2 to 4 mg/liter) were to be treated with meropenem, a dose of 500 mg every 6 h would be necessary: a bolus over 30 min for oligoanuric patients and an infusion over 3 h for patients with preserved diuresis. Our results suggest that residual diuresis may be an easy and

  5. Meropenem Population Pharmacokinetics in Critically Ill Patients with Septic Shock and Continuous Renal Replacement Therapy: Influence of Residual Diuresis on Dose Requirements

    PubMed Central

    Llaurado-Serra, Mireia; Vaquer, Sergi; Castro, Pedro; Rodríguez, Alejandro H.; Pontes, Caridad; Calvo, Gonzalo; Torres, Antoni; Martín-Loeches, Ignacio

    2015-01-01

    Meropenem dosing in critically ill patients with septic shock and continuous renal replacement therapy (CRRT) is complex, with the recommended maintenance doses being 500 mg to 1,000 mg every 8 h (q8h) to every 12 h. This multicenter study aimed to describe the pharmacokinetics (PKs) of meropenem in this population to identify the sources of PK variability and to evaluate different dosing regimens to develop recommendations based on clinical parameters. Thirty patients with septic shock and CRRT receiving meropenem were enrolled (153 plasma samples were tested). A population PK model was developed with data from 24 patients and subsequently validated with data from 6 patients using NONMEM software (v.7.3). The final model was characterized by CL = 3.68 + 0.22 · (residual diuresis/100) and V = 33.00 · (weight/73)2.07, where CL is total body clearance (in liters per hour), residual diuresis is the volume of residual diuresis (in milliliters per 24 h), and V is the apparent volume of distribution (in liters). CRRT intensity was not identified to be a CL modifier. Monte Carlo simulations showed that to maintain concentrations of the unbound fraction (fu) of drug above the MIC of the bacteria for 40% of dosing interval T (referred to as 40% of the ƒuT>MIC), a meropenem dose of 500 mg q8h as a bolus over 30 min would be sufficient regardless of the residual diuresis. If 100% of the ƒuT>MIC was chosen as the target, oligoanuric patients would require 500 mg q8h as a bolus over 30 min for the treatment of susceptible bacteria (MIC < 2 mg/liter), while patients with preserved diuresis would require the same dose given as an infusion over 3 h. If bacteria with MICs close to the resistance breakpoint (2 to 4 mg/liter) were to be treated with meropenem, a dose of 500 mg every 6 h would be necessary: a bolus over 30 min for oligoanuric patients and an infusion over 3 h for patients with preserved diuresis. Our results suggest that residual diuresis may be an easy and

  6. Hypotensive and Angiotensin-Converting Enzyme Inhibitory Activities of Eisenia fetida Extract in Spontaneously Hypertensive Rats

    PubMed Central

    Mao, Shumei; Li, Chengde

    2015-01-01

    Objectives. This study aimed to investigate the antihypertensive effects of an Eisenia fetida extract (EFE) and its possible mechanisms in spontaneously hypertensive rats (SHR rats). Methods. Sixteen-week-old SHR rats and Wistar-Kyoto rats (WKY rats) were used in this study. Rats were, respectively, given EFE (EFE group), captopril (captopril group), or phosphate-buffered saline (PBS) (normal control group and SHR group) for 4 weeks. ACE inhibitory activity of EFE in vitro was determined. The systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured using a Rat Tail-Cuff Blood Pressure System. Levels of angiotensin II (Ang II), aldosterone (Ald), and 6-keto-prostaglandin F1 alpha (6-keto-PGF1α) in plasma were determined by radioimmunoassay, and serum nitric oxide (NO) concentration was measured by Griess reagent systems. Results. EFE had marked ACE inhibitory activity in vitro (IC50 = 2.5 mg/mL). After the 4-week drug management, SHR rats in EFE group and in captopril group had lower SBP and DBP, lower levels of Ang II and Ald, and higher levels of 6-keto-PGF1α and NO than the SHR rats in SHR group. Conclusion. These results indicate that EFE has hypotensive effects in SHR rats and its effects might be associated with its ACE inhibitory activity. PMID:26798397

  7. Granulomatosis With Polyangiitis-Associated Hypertrophic Pachymeningitis Mimicking Spontaneous Intracranial Hypotension: A Case Report.

    PubMed

    Jung, Young Hee; Lee, Mi Ji; Lee, Chungbin; Cha, Jihoon; Chung, Chin-Sang

    2017-03-01

    Dural enhancement is a characteristic finding in both spontaneous intracranial hypotension and hypertrophic pachymeningitis. Positional headache is the most important feature that distinguishes the two diseases. We report a patient with granulomatosis with polyangiitis (formerly Wegener's granulomatosis) who initially manifested like spontaneous intracranial hypotension. We report here the case of a 63-year old man who presented with severe positional headache. The patient had typical symptoms, symmetric dural enhancement, and a recent history of nontraumatic subdural hygroma which led to the diagnosis of spontaneous intracranial hypotension, but was finally diagnosed as granulomatosis with polyangiitis-associated secondary hypertrophic pachymeningitis. Cyclophosphamide therapy was effective for the maintenance of remission. Hypertrophic pachymeningitis associated with granulomatosis with polyangiitis can present with positional headache and subdural hygroma, mimicking spontaneous intracranial hypotension. Granulomatosis with polyangiitis should be suspected when patients with spontaneous intracranial hypotension or hypertrophic pachymeningitis show atypical features. © 2016 American Headache Society.

  8. Marked elevation of procalcitonin level can lead to a misdiagnosis of anaphylactic shock as septic shock.

    PubMed

    Kim, Young Jun; Kang, Sang Woo; Lee, Jae Hoon; Cho, Ji Hyun

    2015-08-01

    The case of a 74-year-old woman who presented with hyperthermia and hypotension is reported. Laboratory test results revealed marked elevation of C-reactive protein (CRP) and procalcitonin (PCT) levels. The clinical presentation and laboratory test results were suggestive of septic shock. No infectious focus was identified. The shock recurred after what was subsequently understood to be an unintended re-challenge with risedronate sodium. Drug-induced anaphylactic shock was finally diagnosed. Anaphylactic shock may be misdiagnosed as septic shock in patients who present with markedly elevated PCT levels. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. Ultrasonography-guided percutaneous nephrolithotomy with Chinese one-shot tract dilation technique based on stimulated diuresis: A report of 67 cases.

    PubMed

    Shi, Ying; Liang, Hua-Geng; Yang, Xiong; Hai, Bo; Wang, Liang; Xing, Yi-Fei; Ju, Wen; Zeng, Fu-Qing; Zhang, Xiao-Ping; Li, Wen-Cheng

    2016-12-01

    The safety and effectiveness of a novel Chinese one-shot dilation technique based on stimulated diuresis for percutaneous nephrolithotomy (PCNL) were investigated. After the feasibility of the Chinese one-shot dilation based on stimulated diuresis was verified by an animal study, this technique was applied in the clinical practice. A total of 67 patients in our department underwent the modified PCNL from July 2014 to June 2015. After the renal infundibulum was distended by stimulated diuresis, the kidney was punctured under the ultrasonographic guidance via the fornix of the target calyx. The working channel was dilated using a special designed pencil-shaped fascial dilator. The successful access rate, nephrostomy tract creation time, pre- and postoperative hemoglobin values and serum creatinine concentrations, stone-free rate and complications were recorded and analyzed. The renal infundibulum was successfully distended in all of the patients by the diuresis treatment. Under the ultrasonographic guidance, the successful access rate was 100% and the mean tract creation time was 2.0 min (range: 1.5-5.0 min). The stone-free rate right after surgery was 91.0%. Although the postoperative hemoglobin was significantly reduced (P<0.01), transfusion was not clinically necessary. There was no significant difference in serum creatinine concentrations before and after operation (P>0.05). No severe complication occurred during or after the PCNL. It was suggested that this Chinese one-shot dilation technique based on stimulated diuresis is an efficient and safe innovation for PCNL, and is even helpful for those patients with non-dilated pelvicaliceal systems.

  10. [Role of V1- and V2-receptors in mechanism of physiological paradox--an increase of reabsorption of the solute free water and simultaneous rise of diuresis].

    PubMed

    Kanashkina, T A; Kuznetsova, A A; Shakhmatova, E I; Natochin, Iu V

    2006-10-01

    In experiments on non-anesthetized rats with administration into stomach of water (5 ml/100 g body mass) direct correlation has been found between an increase of diuresis and excretion of solute free water (r = 0.98, p < 0.01), while after injection to these animals of 5 x 10(-11) M arginine-vasotocin - between an increase of diuresis and simultaneous rise reabsorption of solute free water (r = 0.8, p < 0.01). The rise of diuresis after the vasotocin injection is due to inhibition of sodium re- absorption, with the solute excretion fraction increasing from 2.6 +/- 0.2 % to 11.9 +/- 1.2, p < 0.001. A similar physiological paradox - an increase of diuresis with the simultaneous increase of reabsorption of solute free water - has been revealed at night hours in children with tendency for nocturnal enuresis (r = 0.64, p < 0.01). Mechanism responsible for this phenomenon consists in a rise of diuresis due to a decrease of sodium ion reabsorption in the ascending Henle loop limb. A problem is discussed of the homeostatic significance of a decrease of sodium reabsorption combined with an increase of solute-free water reabsorption; it is suggested that this phenomenon is based on a redistribution of reabsorption inside the nephron - a decrease of ion and water reabsorption in the initial parts of the nephron distal segment and an increase of solute free water reabsorption with the antidiuretic hormone-stimulated high osmotic permeability of terminal parts of renal tubules. An intraperitoneal injection of V1-anatagonist (OPC-21268) decreased the natriuretic component of response to arginine-vasotocin, while injection of V2-antagonist (OPC-31260) eliminated the antidiuretic component.

  11. Role of cerebral oxygenation for prediction of hypotension after spinal anesthesia for caesarean section.

    PubMed

    Sun, Shen; Liu, Nai-He; Huang, Shao-Qiang

    2016-08-01

    To investigate the role of cerebral oxygen saturation (ScO2) for prediction of hypotension after spinal anesthesia for caesarean section. Forty-five parturients undergoing elective caesarean section under spinal anesthesia were selected. Blood pressure, heart rate and pulse oxygen saturation before and after anesthesia were recorded, and the association between changes in ScO2 before and after anesthesia with hypotension after spinal anesthesia was explored. Hypotension occurred in 32 parturients after spinal anesthesia. The decrease in ScO2 after spinal anesthesia in parturients with hypotension was larger than in parturients without hypotension (P < 0.05). The duration from the intrathecal injection to 5 % decrease in ScO2 was shorter than that from the intrathecal injection to the occurrence of hypotension (P < 0.05). The mean time from 5 % decrease in ScO2 to hypotension was 38 s. The area under the receiver operation characteristic curve was 0.83 for decrease in ScO2 for prediction of hypotension (P < 0.05), and the optimal threshold value was 4.5 %. The sensitivity, specificity, positive predictive value and negative predictive value of 4.5 % decrease in ScO2 for prediction of hypotension were 0.75, 0.78, 0.92 and 0.47, respectively. The decrease in ScO2 after spinal anesthesia is associated with hypotension after spinal anesthesia for cesarean section, and may be a clinically useful predictor.

  12. Dynamic FDG PET/CT imaging with diuresis demonstrates an enterovesical fistula in a lymphoma patient with repeated colon diverticulitis.

    PubMed

    Kao, Pan-Fu; Ting, Wen-Chien; Hsiao, Pei-Ching; Kao, Yu-Lin; Chang, Pai-Jung; Lee, Jong-Kang

    2013-04-01

    A 43-year-old male patient with follicular B-cell lymphoma was referred for a FDG PET/CT scan due to severe left lower abdominal pain to rule out recurrent cancer. These FDG PET/CT images and previous FDG PET/CT images 5 months ago both revealed an air bubble in the urinary bladder on the CT images. He had a recurrent urinary tract infection history for 6 months. A list-mode dynamic data acquisition with diuresis intravenous injection revealed linear FDG activity extending from the upper-left portion of the bladder to a soft tissue mass in the lower-left pelvic region. An enterovesical fistula was confirmed by surgery.

  13. Mark 3 system overview

    NASA Technical Reports Server (NTRS)

    Clark, T. A.

    1980-01-01

    The Mark 3 very long baseline interferometry (VLBI) system, comprising a complete end to end VLBI system optimized for both high accuracy geodesy and radio astronomy, is described. The data flow, the data base handler system, and the field station component and configurations are briefly discussed. The use of mobile and transportable stations allows measurements to be taken from a large number of sites with relatively few sets of equipment. Fixed stations form a long term reference network for tying together the measurements with the mobile and transportable stations.

  14. Microinjection of glycine into the hypothalamic paraventricular nucleus produces diuresis, natriuresis, and inhibition of central sympathetic outflow.

    PubMed

    Krowicki, Zbigniew K; Kapusta, Daniel R

    2011-04-01

    Strychnine-sensitive glycine receptors and glycine-immunoreactive fibers are expressed in the hypothalamic paraventricular nucleus (PVN), yet the functional significance of this innervation is unclear. Therefore, these studies examined the changes in cardiovascular and renal function and renal sympathetic nerve activity (RSNA) produced by the microinjection of glycine (5 and 50 nmol) into the PVN of conscious Sprague-Dawley rats. Microinjection of glycine into, but not outside of, the PVN dose-dependently increased urine flow rate and urinary sodium excretion and decreased RSNA. At the higher dose, PVN glycine also decreased heart rate; neither 5 nor 50 nmol PVN glycine altered mean arterial pressure. The glycine (50 nmol)-evoked diuresis and natriuresis were abolished in rats continuously infused intravenously with [Arg(8)]-vasopressin. Furthermore, chronic bilateral renal denervation prevented the bradycardia and diuresis to PVN glycine and blunted the natriuresis. In other studies, unilateral PVN pretreatment with the glycine receptor antagonist strychnine (1.6 nmol) prevented the effects of PVN glycine (50 nmol) on heart rate, RSNA, and renal excretory function. When microinjected bilaterally, PVN strychnine (1.6 nmol per site) evoked a significant increase in heart rate and RSNA without altering renal excretory function. These findings demonstrate that in conscious rats glycine acts in the PVN to enhance the renal excretion of water and sodium and decrease central sympathetic outflow to the heart and kidneys. Although endogenous PVN glycine inputs elicit a tonic control of heart rate and RSNA, the renal excretory responses to PVN glycine seem to be caused primarily by the inhibition of arginine vasopressin secretion.

  15. Patterns of renal dopamine release to regulate diuresis and natriuresis during volume expansion. Role of renal monoamine-oxidase.

    PubMed

    de Luca Sarobe, Verónica; Di Ciano, Luis; Carranza, Andrea M; Levin, Gloria; Arrizurieta, Elvira E; Ibarra, Fernando R

    2010-01-01

    Diuretic and natriuretic effects of renal dopamine (DA) are well established. However, in volume expansion the pattern of renal DA release into urine (UDAV) and the role of enzymes involved in DA synthesis/degradation have not yet been defined. The objective was to determine the pattern of UDAV during volume expansion and to characterize the involvement of monoamine-oxidase (MAO) and aromatic amino-acid decarboxylase (AADC) in this response. In this study male Wistar rats were expanded with NaCl 0.9% at a rate of 5% BWt per hour. At the beginning of expansion three groups received a single drug injection as follows: C (vehicle, Control), IMAO (MAO inhibitor Pargyline, 20 mg/kg BWt, i.v.) and BNZ (AADC inhibitor Benserazide, 25 mg/kg BWt, i.v.). Results revealed that in C rats UDAV (ng/30 min/100g BWt) increased in the first 30 min expansion from 11.5 +/- 1.20 to 21.8 +/- 3.10 (p < 0.05) and decreased thereafter. IMAO showed a similar pattern but significantly higher than C at 30 min expansion (32.5 +/- 2.20, p < 0.05). IMAO greatly reduced MAO activity from 8.29 +/- 0.35 to 1.1 +/- 0.03 nmol/mg tissue/hour and significantly increased diuresis and natriuresis over controls. BNZ abolished the early UDAV peak to 3.2+/-0.72 (p < 0.01) and though, UDAV increased over C after 60 min expansion, natriuresis and diuresis were diminished by BNZ treatment. Results indicate that an increment in renal DA release into urine occurs early in expansion and in a peak-shaped way. In this response MAO plays a predominant role.

  16. Diuresis and reduced urinary osmolality in rats produced by small-molecule UT-A-selective urea transport inhibitors

    PubMed Central

    Esteva-Font, Cristina; Cil, Onur; Phuan, Puay-Wah; Su, Tao; Lee, Sujin; Anderson, Marc O.; Verkman, A. S.

    2014-01-01

    Urea transport (UT) proteins of the UT-A class are expressed in epithelial cells in kidney tubules, where they are required for the formation of a concentrated urine by countercurrent multiplication. Here, using a recently developed high-throughput assay to identify UT-A inhibitors, a screen of 50,000 synthetic small molecules identified UT-A inhibitors of aryl-thiazole, γ-sultambenzosulfonamide, aminocarbonitrile butene, and 4-isoxazolamide chemical classes. Structure-activity analysis identified compounds that inhibited UT-A selectively by a noncompetitive mechanism with IC50 down to ∼1 μM. Molecular modeling identified putative inhibitor binding sites on rat UT-A. To test compound efficacy in rats, formulations and administration procedures were established to give therapeutic inhibitor concentrations in blood and urine. We found that intravenous administration of an indole thiazole or a γ-sultambenzosulfonamide at 20 mg/kg increased urine output by 3–5-fold and reduced urine osmolality by ∼2-fold compared to vehicle control rats, even under conditions of maximum antidiuresis produced by 1-deamino-8-d-arginine vasopressin (DDAVP). The diuresis was reversible and showed urea > salt excretion. The results provide proof of concept for the diuretic action of UT-A-selective inhibitors. UT-A inhibitors are first in their class salt-sparing diuretics with potential clinical indications in volume-overload edemas and high-vasopressin-associated hyponatremias.—Esteva-Font, C., Cil, O., Phuan, P.-W., Su, T., Lee, S., Anderson, M. O., Verkman, A. S. Diuresis and reduced urinary osmolality in rats produced by small-molecule UT-A-selective urea transport inhibitors. PMID:24843071

  17. Effect of P2X4 and P2X7 receptor antagonism on the pressure diuresis relationship in rats

    PubMed Central

    Menzies, Robert I.; Unwin, Robert J.; Dash, Ranjan K.; Beard, Daniel A.; Cowley Jr., Allen W.; Carlson, Brian E.; Mullins, John J.; Bailey, Matthew A.

    2013-01-01

    Reduced glomerular filtration, hypertension and renal microvascular injury are hallmarks of chronic kidney disease, which has a global prevalence of ~10%. We have shown previously that the Fischer (F344) rat has lower GFR than the Lewis rat, and is more susceptible to renal injury induced by hypertension. In the early stages this injury is limited to the pre-glomerular vasculature. We hypothesized that poor renal hemodynamic function and vulnerability to vascular injury are causally linked and genetically determined. In the present study, normotensive F344 rats had a blunted pressure diuresis relationship, compared with Lewis rats. A kidney microarray was then interrogated using the Endeavour enrichment tool to rank candidate genes for impaired blood pressure control. Two novel candidate genes, P2rx7 and P2rx4, were identified, having a 7− and 3− fold increased expression in F344 rats. Immunohistochemistry localized P2X4 and P2X7 receptor expression to the endothelium of the pre-glomerular vasculature. Expression of both receptors was also found in the renal tubule; however there was no difference in expression profile between strains. Brilliant Blue G (BBG), a relatively selective P2X7 antagonist suitable for use in vivo, was administered to both rat strains. In Lewis rats, BBG had no effect on blood pressure, but increased renal vascular resistance, consistent with inhibition of some basal vasodilatory tone. In F344 rats BBG caused a significant reduction in blood pressure and a decrease in renal vascular resistance, suggesting that P2X7 receptor activation may enhance vasoconstrictor tone in this rat strain. BBG also reduced the pressure diuresis threshold in F344 rats, but did not alter its slope. These preliminary findings suggest a physiological and potential pathophysiological role for P2X7 in controlling renal and/or systemic vascular function, which could in turn affect susceptibility to hypertension-related kidney damage. PMID:24187541

  18. Diuresis and natriuresis caused by activation of VR1-positive sensory nerves in renal pelvis of rats.

    PubMed

    Zhu, Yi; Wang, Youping; Wang, Donna H

    2005-10-01

    To test the hypothesis that activation of the vanilloid receptor 1 (VR1) expressed in sensory nerves innervating the renal pelvis leads to diuresis and natriuresis, a selective VR1 receptor agonist, capsaicin (2.4 nmol), or vehicle was perfused intravenously or into the left renal pelvis of anesthetized rats at a rate without changing renal perfusion pressure. Mean arterial pressure was not altered by capsaicin administered intravenously or into the renal pelvis. Capsaicin perfusion into the left renal pelvis but not intravenously caused significant increases in urine flow rate and urinary sodium excretion bilaterally in a dose-dependent manner, which were abolished by capsazepine, a selective VR1 receptor antagonist, given ipsilaterally to the renal pelvis or by ipsilateral renal denervation. Capsaicin given intravenously or into the left renal pelvis increased plasma calcitonin gene-related peptide levels to the same extent. Increased plasma calcitonin gene-related peptide levels induced by capsaicin (68.9+/-2.8 pg/mL) perfusion into the renal pelvis was prevented either by capsazepine (22.5+/-10.1 pg/mL) given ipsilaterally into the renal pelvis or by ipsilateral renal denervation (25.9+/-2.3 pg/mL). Taken together, our data show that unilateral activation of VR1-positive sensory nerves innervating the renal pelvis leads to bilateral diuresis and natriuresis via a mechanism that is independent of plasma calcitonin gene-related peptide levels. These data suggest that VR1-positive sensory nerves in the kidney enhance renal excretory function, a mechanism that may be critically involved in sodium and fluid homeostasis.

  19. Early metabolic effects of hypotension on rat kidney.

    PubMed

    Freeman, D M; Chan, L; Yahaya, H; Holloway, P; Ross, B D

    1989-01-01

    Saturation-transfer phosphorus nuclear magnetic resonance (STNMR) has been applied to the rat kidney in vivo. The rate of renal metabolism determined by this method compares favorably with the renal oxygen consumption, assuming an ATP:oxygen ratio of 2. Hemorrhagic hypotension resulted in a 20% fall in renal blood flow and a significant fall in oxygen consumption. The rate of renal metabolism fell by 50%. This rate of ATP synthesis was below that required to maintain a normal [ATP], but renal [Pi] was not increased. When renal perfusion was reduced by 60%, intrarenal [Pi] rose. When [P1] was elevated, the method os STNMR no longer gave a reliable measure of the rate ATP synthesis, indicating that this new Pi pool was not in rapid chemical exchange with ATP. STNMR represents a useful noninvasive means of monitoring renal metabolic rate, with limitations due to insensitivity and the existence of multiple pools of intrarenal Pi.

  20. Pathophysiology and management of spontaneous intracranial hypotension--a review.

    PubMed

    Syed, Nadir Ali; Mirza, Farhan Arshad; Pabaney, Aqueel Hussain; Rameez-ul-Hassan

    2012-01-01

    Spontaneous Intracranial Hypotension is a syndrome involving reduced intracranial pressure secondary to a dural tear which occurs mostly due to connective tissue disorders such as Marfans Syndrome, and Ehler Danlos Syndrome. Patients with dural ectasias leading to CSF leakage into the subdural or epidural space classically present with orthostatic headaches and cranial nerve deficits mostly seen in cranial nerves V-VIII. Diagnosis of SIH is confirmed with the aid of neuroimaging modalities of which Cranial MR imaging is most widely used. SIH can be treated conservatively or with epidural blood patches which are now widely being used to repair dural tears, and their effectiveness is being recognized. Recently epidural injection of fibrin glue has also been used which has been found to be effective in certain patients.

  1. Spontaneous intracranial hypotension resulting from a thoracic osteophyte.

    PubMed

    Hung, Ling-Chien; Hsu, Yung-Chu

    2015-06-01

    We report a 34-year-old woman who presented with progressive postural headache and neck tightness over 1week. We confirmed the diagnosis of spontaneous intracranial hypotension (SIH) and spinal images showed a thoracic osteophyte caused the cerebrospinal fluid (CSF) leak. SIH caused by spinal CSF leak is generally thought to be a consequence of deficiency of the spinal meninges in conjunction with trivial trauma. Less commonly, spinal bony pathology can lead to SIH. We reviewed 13 reported patients with bony structural pathology related SIH. After two to three epidural blood patches, eight patients underwent surgery. They generally had good outcomes. In conclusion, even though surgical repair confers specific risks, it should be considered after repetitive failures of epidural blood patches. The long-term prognoses of surgical versus non-surgical patients warrants further investigation.

  2. Neurogenic orthostatic hypotension – management update and role of droxidopa

    PubMed Central

    Vijayan, Joy; Sharma, Vijay K

    2015-01-01

    Orthostatic hypotension (OH) is defined as a significant decrease in blood pressure (BP) during the first 3 minutes of standing or a head up on a tilt table. Symptoms of OH are highly variable, ranging from mild light-headedness to recurrent syncope. OH occurs due to dysfunction of one or more components of various complex mechanisms that interplay closely to maintain BP in a normal range during various physiological and associated disease states. Various biochemical and electrophysiological studies are often undertaken to assess the severity and etiology of OH. In addition to the lifestyle modifications, various medications that stimulate the adrenergic receptors or increase central blood volume are used in patients with OH. Droxidopa is a newer agent that increases the levels of norepinephrine in postganglionic sympathetic neurons. Management strategies for OH are presented, including the mechanism of action of droxidopa and various studies performed to assess its efficacy. PMID:26089676

  3. [Spontaneous cerebrospinal fluid leak may cause intracranial hypotension].

    PubMed

    Christiansen, Ingelise

    2015-01-05

    Spontaneous intracranial hypotension (SIH) is often misinterpreted as migraine or tension headache. This type of headache is, however, orthostatic and resolves in supine position. CT scan/MRI of the brain has characteristic findings, enhancement of the pachymeninges and bilateral hygroma. An extreme situation of a 70-year-old woman with sagging midbrain is described in this case report. Although this type of headache may be caused by a dural fistula with spinal fluid leak it is not necessary to locate the lesion with myelografi/MR. Timely treatment with an epidural blood patch at any lumbal level could prevent potentially life-threatening complications and the headache resolved within hours/few days.

  4. Effects of propranolol in a case of orthostatic hypotension.

    PubMed Central

    Brevetti, G; Chiariello, M; Lavecchia, G; Rengo, F

    1979-01-01

    In a hypertensive patient with orthostatic hypotension, the changes in several haemodynamic indices with respect to posture were evaluated. In the upright position, systemic blood pressure was reduced as compared with the supine position, and peripheral vasodilation was present, as shown by an increase in Jantsch's index of the impedance plethysmographic tracings. Systolic time intervals remained unchanged with changes in posture. Propranolol 10 mg intravenously brought the response to normal. In fact, after beta-blockade in the standing position the blood pressure remained unchanged and normal peripheral vasoconstriction was observed. Similar results were seen during atrial pacing at a constant heart rate of 130 beats/minute. In this patient, propranolol appears to normalise the response to the posture change, by restoring normal vasoconstriction in the upright position. PMID:426969

  5. Noise-induced compensation for postural hypotension in primary autonomic failure.

    PubMed

    Yamamoto, Yoshiharu; Hidaka, Ichiro; Iso-o, Noriko; Komai, Akira; Soma, Rika; Kwak, Shin

    2002-07-26

    Noise can have a beneficial effect on sensory neurological systems, enhancing detection of small afferent signals and thereby improve efferent neural responses. We hypothesized whether a similar mechanism would facilitate impaired neural transmission associated with neurological disease, and tested whether addition of external noise to baroreceptor signaling could improve blunted autonomic efferent responses to a postural challenge in patients with primary autonomic failure (PAF). Five PAF patients were tested, one in duplicate and another triplicate, for their transient responses of heart rate (measured from electrocardiographic RR intervals; RRIs) and systolic (SBP) and diastolic (DBP) blood pressures to either 30 degrees or 60 degrees head-up tilt, with and without continuous application of beat-to-beat Gaussian white noise to the carotid sinus baroreceptors. Also, the effects of noise were compared with those by a continuous positive pressure applied to the carotid sinus baroreceptors. The data were fit to a first order model to evaluate the speed (by the time constant; tau) and the magnitudes (by the steady state gains; Gs) of RRI and blood pressure responses. The PAF patients exhibited marked drops in SBP and DBP and a blunted increase in heart rate upon transition from a supine to a head-up position. Addition of noise, not the continuous positive pressure, to the arterial baroreceptors significantly (P<0.05) increased the G in RRI and diminished the Gs in SBP and DBP, though the time courses (taus) of both the RRI and blood pressure responses were unaffected. The addition of external noise to baroreceptor signaling ameliorated the marked postural hypotension seen in patients with PAF.

  6. Minimal Marking: A Success Story

    ERIC Educational Resources Information Center

    McNeilly, Anne

    2014-01-01

    The minimal-marking project conducted in Ryerson's School of Journalism throughout 2012 and early 2013 resulted in significantly higher grammar scores in two first-year classes of minimally marked university students when compared to two traditionally marked classes. The "minimal-marking" concept (Haswell, 1983), which requires…

  7. Case Marking Strategies in Kope.

    ERIC Educational Resources Information Center

    Clifton, John

    Case marking strategies in Kope, a Papuan language of Papua New Guinea, are analyzed in light of previous claims that most Papuan languages have one strategy for marking core relations and another for marking peripheral relations. A brief grammatical overview illustrates how core and peripheral relations are marked in Kope, including nominal case…

  8. Fludrocortisone does not prevent orthostatic hypotension in astronauts after spaceflight.

    PubMed

    Shi, Shang-Jin; South, Donna A; Meck, Janice V

    2004-03-01

    During stand/tilt tests after spaceflight, 20% of astronauts experience orthostatic hypotension and presyncope. Spaceflight-induced hypovolemia is a contributing factor. Fludrocortisone, a synthetic mineralocorticoid, has been shown to increase plasma volume and orthostatic tolerance in Earth-bound patients. The efficacy of fludrocortisone as a treatment for postflight hypovolemia and orthostatic hypotension in astronauts has not been studied. Our purpose was to test the hypothesis that astronauts who ingest fludrocortisone prior to landing would have less loss of plasma volume and greater orthostatic tolerance than astronauts who do not ingest fludrocortisone. There were 25 male astronauts who were randomized into 2 groups: placebo (n = 18) and fludrocortisone (n = 7), and participated in stand tests 10 d before launch and 2-4 h after landing. Subjects took either 0.3 mg fludrocortisone or placebo orally 7 h prior to landing. Supine plasma and red cell volumes, supine and standing HR, arterial pressure, aortic outflow, and plasma norepinephrine and epinephrine were measured. On landing day, 2 of 18 in the placebo group and 1 of 7 in the fludrocortisone group became presyncopal (chi2 = 0.015, p = 0.90). Plasma volumes were significantly decreased after flight in the placebo group, but not in the fludrocortisone group. During postflight stand tests, standing plasma norepinephrine was significantly less in the fludrocortisone group compared with the placebo group. Treatment with a single dose of fludrocortisone results in protection of plasma volume but no protection of orthostatic tolerance. Fludrocortisone is not recommended as a countermeasure for spaceflight-induced orthostatic intolerance.

  9. Prevention of dialysis hypotension episodes using fuzzy logic control system.

    PubMed

    Mancini, Elena; Mambelli, Emanuele; Irpinia, Mina; Gabrielli, Danila; Cascone, Carmelo; Conte, Ferruccio; Meneghel, Gina; Cavatorta, Fosco; Antonelli, Alessandro; Villa, Giuseppe; Dal Canton, Antonio; Cagnoli, Leonardo; Aucella, Filippo; Fiorini, Fulvio; Gaggiotti, Enzo; Triolo, Giorgio; Nuzzo, Vitale; Santoro, Antonio

    2007-05-01

    Automatic systems for stabilizing blood pressure (BP) during dialysis are few and only control those variables indirectly related to BP. Due to complex BP regulation under dynamic dialysis conditions, BP itself appears to be the most consistent input parameter for a device addressed to preventing dialysis hypotension (DH). An automatic system (ABPS, automatic blood pressure stabilization) for BP control by fluid removal feedback regulation is implemented on a dialysis machine (Dialog Advanced, Braun). A fuzzy logic (FL) control runs in the system, using instantaneous BP as the input variable governing the ultrafiltration rate (UFR) according to the BP trend. The system is user-friendly and just requires the input of two data: critical BP (individually defined as the possible level of DH risk) and the highest UFR applicable (percentage of the mean UFR). We evaluated this system's capacity to prevent DH in 55 RDT hypotension-prone patients. Sessions with (treatment A) and without (treatment B) ABPS were alternated one-by-one for 30 dialysis sessions per patient (674 with ABPS vs 698 without). Despite comparable treatment times and UF volumes, severe DH appeared in 8.3% of sessions in treatment A vs 13.8% in treatment B (-39%, P=0.01). Mild DH fell non-significantly (-12.3%). There was a similar percentage of sessions in which the planned body weight loss was not achieved and dialysis time was prolonged. In conclusion, FL may be suited to interpreting and controlling the trend of a determined multi-variable parameter like BP. The medical knowledge of the patient and the consequent updating of input parameters depending on the patient's clinical conditions seem to be the main factors for obtaining optimal results.

  10. Pharmacognosy and hypotensive evaluation of Ficus exasperata Vahl (Moraceae) leaf.

    PubMed

    Ayinde, Buniyamin A; Omogbai, Eric K I; Amaechina, Fabian C

    2007-01-01

    There is already a literature report on the anti-ulcer effect of water extract of Ficus exasperata. Some communities in Edo and Delta States of Nigeria use the decoction of the leaf as hypotensive crude drug. Verification of this claim and also the microscopy and other pharmacognostic parameters which can be used to establish the identity of the leaf were carried out. The microscopy of the leaf powder revealed the presence of straight walled epidermal cells, cone or nail shaped trichomes or epidermal hairs, clustered or prismatic calcium oxalate crystals of varying dimensions. The percentage weight loss on drying was 9.84 +/- 0.08 whereas water and alcohol extractive values were 5.29 +/- 0.07 and 2.21 +/- 0.11, respectively. The ash value was 30.68 +/- 0.44 whereas the acid insoluble ash and water soluble ash values were 17.87 +/- 0.37 and 16.73 +/- 0.13, respectively. Preliminary phytochemistry of leaf showed that it contains tannins, flavonoids and saponins with no traces of alkaloids or anthraquinones. The water extract showed a dose related reduction in mean arterial blood pressure. At 10 mg/kg, a reduction of 16.6 +/- 1.1 mmHg was observed, whereas at 30 mg/kg, a fall in mean arterial pressure of 38.3 +/- 0.6 mmHg was obtained. The hypotensive effect of the extract was significantly reduced with a prior administration of 2.5 mg of either atropine or chlorpheniramine. This suggests the probable stimulation of muscarinic receptors in the heart or release of histamine into the circulatory system thereby causing the initial fall in blood pressure.

  11. The Mark 3 Haploscope

    NASA Technical Reports Server (NTRS)

    Decker, T. A.; Williams, R. E.; Kuether, C. L.; Logar, N. D.; Wyman-Cornsweet, D.

    1975-01-01

    A computer-operated binocular vision testing device was developed as one part of a system designed for NASA to evaluate the visual function of astronauts during spaceflight. This particular device, called the Mark 3 Haploscope, employs semi-automated psychophysical test procedures to measure visual acuity, stereopsis, phoria, fixation disparity, refractive state and accommodation/convergence relationships. Test procedures are self-administered and can be used repeatedly without subject memorization. The Haploscope was designed as one module of the complete NASA Vision Testing System. However, it is capable of stand-alone operation. Moreover, the compactness and portability of the Haploscope make possible its use in a broad variety of testing environments.

  12. Hypotensive Response Magnitude and Duration in Hypertensives: Continuous and Interval Exercise

    PubMed Central

    de Carvalho, Raphael Santos Teodoro; Pires, Cássio Mascarenhas Robert; Junqueira, Gustavo Cardoso; Freitas, Dayana; Marchi-Alves, Leila Maria

    2015-01-01

    Background Although exercise training is known to promote post-exercise hypotension, there is currently no consistent argument about the effects of manipulating its various components (intensity, duration, rest periods, types of exercise, training methods) on the magnitude and duration of hypotensive response. Objective To compare the effect of continuous and interval exercises on hypotensive response magnitude and duration in hypertensive patients by using ambulatory blood pressure monitoring (ABPM). Methods The sample consisted of 20 elderly hypertensives. Each participant underwent three ABPM sessions: one control ABPM, without exercise; one ABPM after continuous exercise; and one ABPM after interval exercise. Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR) and double product (DP) were monitored to check post-exercise hypotension and for comparison between each ABPM. Results ABPM after continuous exercise and after interval exercise showed post-exercise hypotension and a significant reduction (p < 0.05) in SBP, DBP, MAP and DP for 20 hours as compared with control ABPM. Comparing ABPM after continuous and ABPM after interval exercise, a significant reduction (p < 0.05) in SBP, DBP, MAP and DP was observed in the latter. Conclusion Continuous and interval exercise trainings promote post-exercise hypotension with reduction in SBP, DBP, MAP and DP in the 20 hours following exercise. Interval exercise training causes greater post-exercise hypotension and lower cardiovascular overload as compared with continuous exercise. PMID:25517389

  13. Orthostatic hypotension, non-dipping and striatal dopamine in Parkinson disease.

    PubMed

    Oh, Yoon-Sang; Kim, Joong-Seok; Chung, Yong-An; You, Ie Ryung; Yang, Dong-Won; Chung, Sung-Woo; Park, Jeong-Wook; Kim, Yeong-In; Lee, Kwang-Soo

    2013-04-01

    Orthostatic hypotension and non-dipping are relatively common autonomic dysfunctions in patients with Parkinson disease (PD). These abnormalities have been thought to occur independently of striatal dopaminergic depletion; however, only little preliminary information is available. In this study, we investigated the association of neurocirculatory changes with striatal dopamine transporter status in 69 patients with early PD. Seventeen patients had orthostatic hypotension and 55 patients were non-dippers. A comparison between cases with and without orthostatic hypotension was insignificant for striatal dopamine transporter uptake. These insignificances continued in a comparison of dippers and non-dippers. These results suggest that sympathetic noradrenergic dysfunctions in PD are independent of striatal dopamine transporter depletion.

  14. Graded Compression Stockings Prevent Post-spaceflight Orthostatic Hypotension

    NASA Technical Reports Server (NTRS)

    Platts, S. H.; Brown, A. K.; Locke, J.; Stenger, M. B.

    2008-01-01

    Post-spaceflight orthostatic intolerance is characterized by hypotension and presyncope in 20-30% of returning astronauts. Previous data from our laboratory suggests that this is largely a result of decreased venous return. Currently, NASA astronauts wear an anti-gravity suit (AGS) which consists of inflatable air bladders over the calves, thighs and abdomen, which are typically pressurized from 0.5 to 1.5 PSI (27 to 78 mmHg). ISS crew members sometimes wear Russian Kentavr suits which consist of laced compression shorts and gaiters, providing 30 mmHg nominally. While these garments are effective during reentry, there are a number of drawbacks that make them impractical for postflight use. We studied the ability of commercially available, custom fit, graded compression stockings (Jobst, 55 mmHg at ankle to 6 mmHg at top of thigh, 25 mmHg mean compression) to prevent postflight orthostatic intolerance, hypothesizing that these garments would prevent orthostatic intolerance following short duration space flight. Crew members from a single Space Shuttle flight were tilted to 80 degrees for 10 min while wearing the stockings (n=5 males) upon arrival at the clinic (2 hrs after landing). Hemodynamic data were compared to data from all crewmembers tilted (without countermeasures) since return to flight (n=9). Two-way, repeated measures ANOVA, using the entire tilt time curve (0-10 min) show that systolic blood pressure (SBP, group effect p=0.008), stroke volume (SV, group effect p=0.003), and cardiac output (CO, group effect p=0.004) were higher in crewmembers who wore the Jobst stockings. A one-way ANOVA comparing the last minute standing also showed that SV (p=0.001) and CO (p less than 0.001) were higher and SBP tended to be higher (p=0.06) in Jobst subjects compared to controls. Control subjects had a higher rate of presyncope than Jobst subjects (3/9 vs 0/5) during the tilt on landing day. Orthostatic hypotension continues to present following spaceflight, despite

  15. Graded Compression Stockings Prevent Post-spaceflight Orthostatic Hypotension

    NASA Technical Reports Server (NTRS)

    Platts, S. H.; Brown, A. K.; Locke, J.; Stenger, M. B.

    2008-01-01

    Post-spaceflight orthostatic intolerance is characterized by hypotension and presyncope in 20-30% of returning astronauts. Previous data from our laboratory suggests that this is largely a result of decreased venous return. Currently, NASA astronauts wear an anti-gravity suit (AGS) which consists of inflatable air bladders over the calves, thighs and abdomen, which are typically pressurized from 0.5 to 1.5 PSI (27 to 78 mmHg). ISS crew members sometimes wear Russian Kentavr suits which consist of laced compression shorts and gaiters, providing 30 mmHg nominally. While these garments are effective during reentry, there are a number of drawbacks that make them impractical for postflight use. We studied the ability of commercially available, custom fit, graded compression stockings (Jobst, 55 mmHg at ankle to 6 mmHg at top of thigh, 25 mmHg mean compression) to prevent postflight orthostatic intolerance, hypothesizing that these garments would prevent orthostatic intolerance following short duration space flight. Crew members from a single Space Shuttle flight were tilted to 80 degrees for 10 min while wearing the stockings (n=5 males) upon arrival at the clinic (2 hrs after landing). Hemodynamic data were compared to data from all crewmembers tilted (without countermeasures) since return to flight (n=9). Two-way, repeated measures ANOVA, using the entire tilt time curve (0-10 min) show that systolic blood pressure (SBP, group effect p=0.008), stroke volume (SV, group effect p=0.003), and cardiac output (CO, group effect p=0.004) were higher in crewmembers who wore the Jobst stockings. A one-way ANOVA comparing the last minute standing also showed that SV (p=0.001) and CO (p less than 0.001) were higher and SBP tended to be higher (p=0.06) in Jobst subjects compared to controls. Control subjects had a higher rate of presyncope than Jobst subjects (3/9 vs 0/5) during the tilt on landing day. Orthostatic hypotension continues to present following spaceflight, despite

  16. Hypotensive Anesthesia versus Normotensive Anesthesia during Major Maxillofacial Surgery: A Review of the Literature

    PubMed Central

    Yoav, Leiser; Abu el-Naaj, Imad

    2015-01-01

    Steady blood pressure within normal limits during surgery is one of the markers of the ideal and skillful anesthesia. Yet, reduced blood pressure is advantageous in some settings because it can contribute to a reduction in overall blood loss and improve the surgical field conditions. Controlled hypotension during anesthesia or hypotensive anesthesia is often used in major maxillofacial operations. Since hypotensive anesthesia carries the risk of hypoperfusion to important organs and tissues, mainly the brain, heart, and kidneys, it cannot be applied safely in all patients. In this paper we review the medical literature regarding hypotensive anesthesia during major maxillofacial surgery, the means to achieve it, and the risks and benefits of this technique, in comparison to normotensive anesthesia. PMID:25811042

  17. Exogenous L-arginine attenuates the effects of angiotensin II on renal hemodynamics and the pressure natriuresis-diuresis relationship.

    PubMed

    Das, Satarupa; Mattson, David L

    2014-04-01

    Administration of exogenous L-arginine (L-Arg) attenuates angiotensin-II (AngII)-mediated hypertension and kidney disease in rats. The present study assessed renal hemodynamics and pressure diuresis-natriuresis in anaesthetized rats infused with vehicle, AngII (20 ng/kg per min i.v.) or AngII + L-Arg (300 μg/kg per min i.v.). Experiments in isolated aortic rings were carried out to assess L-Arg effects on the vasculature. Increasing renal perfusion pressure (RPP) from ~100 to 140 mmHg resulted in a nine- to tenfold increase in urine flow and sodium excretion rate in control animals. In comparison, AngII infusion significantly reduced renal blood flow (RBF) and glomerular filtration rate (GFR) by 40-42%, and blunted the pressure-dependent increase in urine flow and sodium excretion rate by 54-58% at elevated RPP. Supplementation of L-Arg reversed the vasoconstrictor effects of AngII and restored pressure-dependent diuresis to levels not significantly different from control rats. Dose-dependent contraction to AngII (10(-10) mol/L to 10(-7) mol/L) was observed with a maximal force equal to 27 ± 3% of the response to 10(-5) mol/L phenylephrine. Contraction to 10(-7) mol/L AngII was blunted by 75 ± 3% with 10(-4) mol/L L-Arg. The influence of L-Arg to blunt AngII-mediated contraction was eliminated by endothelial denudation or incubation with nitric oxide synthase inhibitors. Furthermore, the addition of 10(-3) mol/L cationic or neutral amino acids, which compete with L-Arg for cellular uptake, blocked the effect of L-Arg. Anionic amino acids did not influence the effects of L-Arg on AngII-mediated contraction. These studies show that L-Arg blunts AngII-mediated vascular contraction by an endothelial- and nitric oxide synthase-dependent mechanism involving cellular uptake of L-Arg.

  18. Exogenous L-Arginine Attenuates the Effects of Angiotensin II on Renal Hemodynamics and the Pressure Natriuresis-Diuresis Relationship

    PubMed Central

    Das, Satarupa; Mattson, David L.

    2014-01-01

    SUMMARY Administration of exogenous L-Arginine (L-Arg) attenuates Angiotensin II (AngII)-mediated hypertension and kidney disease in rats. The present study assessed renal hemodynamics and pressure-diuresis-natriuresis in anesthetized rats infused with vehicle, AngII (20 ng/kg/min, iv) or AngII + L-Arg (300 µg/kg/min, iv). Increasing renal perfusion pressure (RPP) from approximately 100 to 140 mmHg resulted in a 9–10 fold increase in urine flow and sodium excretion rate in control animals. In comparison, AngII infusion significantly reduced renal blood flow (RBF) and glomerular filtration rate (GFR) by 40–42% and blunted the pressure-dependent increase in urine flow and sodium excretion rate by 54–58% at elevated RPP. Supplementation of L-Arg reversed the vasoconstrictor effects of AngII and restored pressure-dependent diuresis to levels not significantly different from control rats. Experiments in isolated aortic rings were performed to assess L-Arg effects on the vasculature. Dose-dependent contraction to AngII (10−10M to 10−7M) was observed with a maximal force equal to 27±3% of the response to 10−5M phenylephrine. Contraction to 10−7M AngII was blunted by 75±3% with 10−4M L-Arg. The influence of L-Arg to blunt AngII mediated contraction was eliminated by endothelial denudation or incubation with nitric oxide synthase inhibitors. Moreover, the addition of 10−3M cationic or neutral amino acids, which compete with L-Arg for cellular uptake, blocked the effect of L-Arg. Anionic amino acids did not influence the effects of L-Arg on AngII-mediated contraction. These studies indicate that L-Arg blunts AngII-mediated vascular contraction by an endothelial- and NOS-dependent mechanism involving cellular uptake of L-Arg. PMID:24472006

  19. Recent advances in orthostatic hypotension presenting orthostatic dizziness or vertigo.

    PubMed

    Kim, Hyun-Ah; Yi, Hyon-Ah; Lee, Hyung

    2015-11-01

    Orthostatic hypotension (OH), a proxy for sympathetic adrenergic failure, is the most incapacitating sign of autonomic failure. Orthostatic dizziness (OD) is known to be the most common symptom of OH. However, recent studies have demonstrated that 30-39 % of patients with OH experienced rotatory vertigo during upright posture (i.e., orthostatic vertigo, OV), which challenges the dogma that OH induces dizziness and not vertigo. A recent population-based study on spontaneously occurring OD across a wide age range showed that the one-year and lifetime prevalence of OD was 10.9 and 12.5 %, respectively. Approximately 83 % of patients with OD had at least one abnormal autonomic function test result. So far, 11 subtypes of OD have been proposed according to the pattern of autonomic dysfunction, and generalized autonomic failure of sympathetic adrenergic and parasympathetic cardiovagal functions was the most common type. Four different patterns of OH, such as classic, delayed, early, and transient type have been found in patients with OD. The head-up tilt test and Valsalva maneuver should be performed for a comprehensive evaluation of sympathetic adrenergic failure in patients with OD/OV. This review summarizes current advances in OH presenting OD/OV, with a particular focus on the autonomic dysfunction associated with OD.

  20. Nitric oxide-dependent hypotensive effects of wax gourd juice.

    PubMed

    Nakashima, Miki; Shigekuni, Yukiko; Obi, Takeshi; Shiraishi, Mitsuya; Miyamoto, Atsushi; Yamasaki, Hideo; Etoh, Takeomi; Iwai, Sumio

    2011-11-18

    The wax gourd (Benincasa hispida (Thunb) Cong.) is a long-season vegetable that has been used in traditional Chinese medicine to treat high blood pressure. However, precise details of its effect and the mechanism of action involved are still lacking. Ten-fold-condensed wax gourd juice was used for the experiments. We measured (1) blood pressure of anesthetized normal Wistar rats in vivo, (2) isolated rat aortic contraction and relaxation, and (3) nitric oxide production from cultured porcine endothelial cells. The rats mentioned had not been treated with the investigational medicine. Intravenous injection of the juice produced a dose-dependent decrease in blood pressure. Treatment with the juice induced concentration-dependent relaxation of isolated rat aortic rings that had been precontracted with noradrenaline. The relaxation induced by the juice was strongly inhibited by treatment with the nitric oxide (NO) synthase inhibitor N(G)-nitro-l-arginine methyl ester hydrochloride (l-NAME) or endothelial denudation. Treatment with the juice produced NO from cultured porcine aortic endothelial cells. This NO production was significantly inhibited by l-NAME. The present findings suggest that wax gourd juice exerts a hypotensive effect via endothelium-dependent vasodilation. The main endothelium-derived relaxing factor involved might be NO. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  1. Exercise training hypotension - Implications for plasma volume, renin, and vasopressin

    NASA Technical Reports Server (NTRS)

    Greenleaf, J. E.; Sciaraffa, D.; Shvartz, E.; Keil, L. C.; Brock, P. J.

    1981-01-01

    The relation of changes in plasma volume, plasma renin activity and arginine vasopressin to changes in resting blood pressure during exercise training is investigated. Resting supine, sitting, and standing systolic and fifth-phase diastolic blood pressures were measured in ten men before and after an eight-day training period on a cycle ergometer in either a hot (39.8 C) or cool (23.8 C) environment, and compared with plasma volume, renin and vasopressin levels, heart rates, maximal oxygen uptakes, rectal temperatures and sweat rates. Following acclimatization, resting supine and sitting diastolic pressures are observed to decrease by 6 and 9 mm Hg, respectively, while no significant changes are found in the diastolic pressures of the control group or the systolic pressures of either group. Resting plasma volume is found to increase by 12.2% in the controls and by 17.6% after acclimatization following the exercise training. Results suggest that the resting hypotension produced is not attributable to changes in resting plasma volume, renin or vasopressin, although heat acclimatization, which leads to large decreases in plasma volume and increases in vasopressin and renin activity, may be useful in the treatment of hypertension.

  2. Orthostatic hypotension and subjective sleep quality in older people.

    PubMed

    McHugh, Joanna E; Fan, Chie W; Kenny, Rose Ann; Lawlor, Brian A

    2012-01-01

    Poor sleep quality and orthostatic hypotension are common complaints in an older population, and both are related to factors such as polypharmacy and depression. However, it is not known whether there is a direct association between the two. Our objective is to investigate a potential association between orthostatic blood pressure response and subjective sleep quality in older people. A within-subjects, cross-sectional design embedded in a larger longitudinal study design. Participants were recruited from the community to visit the TRIL clinic at St James's Hospital, where they underwent a structured medical and psychosocial assessment. A total of 505 community dwelling adults aged 60+ (321 females, mean age 72.44) were participated in this study. Orthostatic blood pressure responses were recorded during an active stand using Finometer equipment, and health-related factors such as pain ratings, co-morbidities, polypharmacy, timed up and go, Mini-Mental State Examination score, body mass index, as well as depression, anxiety, age and gender, were also recorded. Self-reported sleep quality was also assessed using the Pittsburgh Sleep Quality Index. The results showed that timed up and go, polypharmacy, depression, anxiety, gender and delayed recovery of blood pressure at orthostasis were associated with subjective poor sleep quality. There is an association between subjective sleep quality and delayed recovery of blood pressure at orthostasis, independent of mental health or polypharmacy effects, in older adults. This link may have implications for the management of sleep disorders in older people.

  3. Prolonged severe hypotension following combined amlodipine and valsartan ingestion.

    PubMed

    Smith, Silas W; Ferguson, Kathy L; Hoffman, Robert S; Nelson, Lewis S; Greller, Howard A

    2008-06-01

    Compared to other calcium channel blockers (CCBs), overdose with dihydropyridine CCBs are considered relatively benign due to their vascular selectivity. Although not a sustained-release preparation, amlodipine's prolonged duration of effect is concerning following overdose. In addition, angiotensin II receptor blocker blunting of vasoconstrictive and sympathetic compensatory responses could exacerbate calcium channel blocker toxicity. We describe severe toxicity associated with an overdose of amlodipine and valsartan. A 75-year-old woman presented to the ED 45 minutes after a witnessed suicidal ingestion of a "handful" of amlodipine and valsartan tablets. Hypotension, which appeared two hours after ingestion, was refractory to crystalloids and colloids, calcium gluconate, epinephrine, norepinephrine, phenylephrine, and vasopressin infusions. High-dose insulin euglycemia (HIE) therapy, and treatment with glucagon and naloxone were successful in improving her hemodynamic status. In this combined overdose, right heart catheterization demonstrated both negative inotropic effects and decreased systemic vascular resistance. Co-ingestion of amlodipine with valsartan produced profound toxicity. Early institution of HIE therapy may be beneficial to reverse these effects.

  4. Hypotension and reduced catecholamines in neuropeptide Y transgenic rats.

    PubMed

    Michalkiewicz, Mieczyslaw; Knestaut, Kriss M; Bytchkova, Elena Yu; Michalkiewicz, Teresa

    2003-05-01

    The neurons that control blood pressure express neuropeptide Y. Administered centrally, this neuropeptide reduces blood pressure and anxiety, together with lowering sympathetic outflow. The generation of neuropeptide Y transgenic rats overexpressing this peptide, under its natural promoter, has allowed us to examine the role of endogenous neuropeptide Y in the long-term control of blood pressure by the sympathetic nervous system. This study tested a hypothesis that endogenous neuropeptide Y acts to reduce blood pressure and catecholamine release. Blood pressure was measured by radiotelemetry in conscious male transgenic and nontransgenic littermates (control). Novel cage with cold water and forced swimming were used as stressors. Catecholamines were determined in 24-hour urine (baseline) and plasma (cold water stress) by a radioenzymatic assay. Blood pressures in baseline and during the stresses were significantly reduced in the transgenic rats. The lower blood pressure was associated with reduced catecholamines, lower decrease in pressure after autonomic ganglionic blockade, and increased longevity. Data obtained through the use of this transgenic rat model support and extend the evidence for the previously postulated sympatholytic and hypotensive effects of neuropeptide Y and provide novel evidence for an important physiological role of endogenous peptide in blood pressure regulation. As indicated by the increased longevity of these rats, in long-term regulation, these buffering actions of neuropeptide Y may have important cardiovascular protective effects against sympathetic hyperexcitation.

  5. Chemical Composition and Hypotensive Effect of Campomanesia xanthocarpa

    PubMed Central

    Sant'Anna, Liane Santariano; Merlugo, Liara; Ehle, Catrine Santos; Limberger, Jessica; Fernandes, Maquelen Blanco; Santos, Marí Castro; Mendez, Andreas Sebastian Loureiro; Paula, Fávero Reisdorfer

    2017-01-01

    Campomanesia xanthocarpa is known in Brazil as Guabiroba and is popularly used for various diseases, such as inflammatory, renal, and digestive diseases and dyslipidemia. The aim of the study was to analyze the chemical composition and investigate the effects of aqueous extract of C. xanthocarpa on the blood pressure of normotensive rats, analyzing the possible action mechanism using experimental and in silico procedures. The extract was evaluated for total phenolic compounds and total flavonoid content. The chemical components were determined by HPLC analyses. Systolic and diastolic blood pressure and heart rate were measured with extract and drugs administration. The leaves of C. xanthocarpa presented the relevant content of phenolics and flavonoids, and we suggested the presence of chlorogenic acid, gallic acid, quercetin, and theobromine. The acute administration of aqueous extract of C. xanthocarpa has a dose-dependent hypotensive effect in normotensive rats, suggesting that the action mechanism may be mediated through the renin-angiotensin system by AT1 receptor blockade and sympathetic autonomic response. Docking studies showed models that indicated an interaction between chlorogenic acid and quercetin with the AT1 receptor (AT1R) active site. The findings of these docking studies suggest the potential of C. xanthocarpa constituents for use as preventive agents for blood pressure. PMID:28584558

  6. Exercise training hypotension - Implications for plasma volume, renin, and vasopressin

    NASA Technical Reports Server (NTRS)

    Greenleaf, J. E.; Sciaraffa, D.; Shvartz, E.; Keil, L. C.; Brock, P. J.

    1981-01-01

    The relation of changes in plasma volume, plasma renin activity and arginine vasopressin to changes in resting blood pressure during exercise training is investigated. Resting supine, sitting, and standing systolic and fifth-phase diastolic blood pressures were measured in ten men before and after an eight-day training period on a cycle ergometer in either a hot (39.8 C) or cool (23.8 C) environment, and compared with plasma volume, renin and vasopressin levels, heart rates, maximal oxygen uptakes, rectal temperatures and sweat rates. Following acclimatization, resting supine and sitting diastolic pressures are observed to decrease by 6 and 9 mm Hg, respectively, while no significant changes are found in the diastolic pressures of the control group or the systolic pressures of either group. Resting plasma volume is found to increase by 12.2% in the controls and by 17.6% after acclimatization following the exercise training. Results suggest that the resting hypotension produced is not attributable to changes in resting plasma volume, renin or vasopressin, although heat acclimatization, which leads to large decreases in plasma volume and increases in vasopressin and renin activity, may be useful in the treatment of hypertension.

  7. Spontaneous Intracranial Hypotension Presenting as a "Pseudo-Chiari 1

    PubMed Central

    Haider, Ali S; Sulhan, Suraj; Watson, Ian T; Leonard, Dean; Arrey, Eliel N; Nguyen, Phu; Layton, Kennith F

    2017-01-01

    Spontaneous intracranial hypotension (SIH) is classified as a decrease in cerebrospinal fluid (CSF) pressure secondary to a CSF leakage and consequent descent of the brain into the foramen magnum. Diagnosing SIH can be difficult due to its overlapping findings with Arnold-Chiari type 1 Malformation (CM1) where the cerebellar tonsils herniate into the foramen magnum. The similarity of both conditions calls for a more reliable imaging technique to localize the CSF leak which could narrow the differential diagnosis and aid in choosing the correct treatment. Here, we present a case of a 28-year-old female, ten weeks post-partum with symptoms similar to SIH. MRI of the brain was remarkable for tonsillar herniation below the foramen magnum. Literature was reviewed for additional neuroradiology techniques that would aid in narrowing our differential diagnosis. Interestingly, computed tomography-, digital subtraction-, and magnetic resonance myelography with intrathecal gadolinium are the preferred techniques for diagnosis of high flow and low flow CSF leaks, respectively. These modalities further aid in choosing the correct treatment while avoiding complications. Literature suggests that treatment for CM1 involves posterior fossa decompression, whereas the mainstay of treatment for SIH involves an epidural blood patch (EBP). Thus, our patient was treated with an EBP and recovered without complication. PMID:28357166

  8. Orthostatic hypotension, balance and falls in Parkinson's disease.

    PubMed

    Matinolli, Maarit; Korpelainen, Juha T; Korpelainen, Raija; Sotaniemi, Kyösti A; Myllylä, Vilho V

    2009-04-15

    Orthostatic hypotension (OH) is a common feature in Parkinson's disease (PD). As the control of balance and gait is already affected by PD per se, OH may further predispose patients to falls and accidents. The study was conducted to evaluate the clinical correlates of OH and its association with mobility and balance in PD. From a total population of 205,000 inhabitants, 120 PD patients were included in the study. Medical data including history of recent falls were collected, and patients were clinically examined using the orthostatic test, the Timed Up & Go test, walking speed, and the quantitative measurement of postural sway. Sixty-three (52.5%) patients had OH in the orthostatic test. Twenty-five (39.5%) patients with and 16 (28.1%) patients without OH (P = 0.614) had fallen during the past 3 months. Patients with OH had significantly increased postural sway in standing compared with patients without OH. However, OH was not associated with mobility or walking speed. The current results support the concept that the control of body balance and OH may be closely linked.

  9. Cerebral autoregulation and symptoms of orthostatic hypotension in familial dysautonomia.

    PubMed

    Fuente Mora, Cristina; Palma, Jose-Alberto; Kaufmann, Horacio; Norcliffe-Kaufmann, Lucy

    2017-07-01

    Familial dysautonomia is an inherited autonomic disorder with afferent baroreflex failure. We questioned why despite low blood pressure standing, surprisingly few familial dysautonomia patients complain of symptomatic hypotension or have syncope. Using transcranial Doppler ultrasonography of the middle cerebral artery, we measured flow velocity (mean, peak systolic, and diastolic), area under the curve, pulsatility index, and height of the dictrotic notch in 25 patients with familial dysautonomia and 15 controls. In patients, changing from sitting to a standing position, decreased BP from 124 ± 4/64 ± 3 to 82 ± 3/37 ± 2 mmHg (p < 0.0001, for both). Despite low BP, all patients denied orthostatic symptoms. Middle cerebral artery velocity fell minimally, and the magnitude of the reductions were similar to those observed in healthy controls, in whom BP upright did not fall. While standing, patients had a greater fall in cerebrovascular resistance (p < 0.0001), an increase in pulsatility (p < 0.0001), and a deepening of the dicrotic notch (p = 0.0010), findings all consistent with low cerebrovascular resistance. No significant changes occurred in controls. Patients born with baroreflex deafferentation retain the ability to buffer wide fluctuations in BP and auto-regulate cerebral blood flow. This explains how they can tolerate extremely low BPs standing that would otherwise induce syncope.

  10. Impact of drugs on intradialytic hypotension: Antihypertensives and vasoconstrictors.

    PubMed

    Chang, Tara I

    2017-07-05

    Intradialytic hypotension (IDH) is a common complication of hemodialysis and is associated with numerous adverse outcomes including cardiovascular events, inadequate dialysis, loss of vascular access, and death. It is estimated that approximately 20%-30% of all dialysis sessions are affected by IDH. In seeking ways to reduce the occurrence of IDH, dialysis providers often turn to pharmacological approaches: withholding antihypertensive medications prior to hemodialysis or administering vasoconstrictor medications. This review will focus on what is known about the relation between antihypertensive medications and IDH, and summarize studies that have examined the efficacy of vasoconstrictor medications on IDH, including midodrine, arginine vasopressin, and droxidopa. However, there is currently scant evidence that any pharmacological approach is particularly effective in reducing IDH. Additional studies of potential treatments for IDH are needed, and should examine not only hemodynamic effects such as changes in nadir blood pressure during dialysis, but also on patient-centered and clinical outcomes such as symptoms of IDH, quality of life, and cardiovascular events. © 2017 Wiley Periodicals, Inc.

  11. A retrospective study to correlate breech presentation and enhanced risk of postspinal hypotension during cesarean delivery

    PubMed Central

    Jain, Anshul; Pandey, Shivali; Kumar, Roopesh; Sethi, Chavi; Sharma, Sanjya

    2015-01-01

    Background Subarachnoid blockade for cesarean section still poses a threat of profound hypotension and can result in unstable maternal and fetal hemodynamics. The correlation of fetal breech and vertex presentation with the occurrence of hypotension under spinal anesthesia is reviewed in this retrospective, double-blind study. Patients and methods The study was conducted on pregnant females scheduled for a lower segment cesarean section between January 2014 and December 2014. After applying inclusion criteria, 568 patients were recruited in the study out of which 363 had vertex and 184 patients had breech presentation. They were divided into two groups, Group I and Group II. The monitoring and therapeutic data (blood pressure, heart rate, arterial oxygen saturation, and dose of vasopressor/atropine) recovered from automated data analysis were analyzed retrospectively for prevalence of hypotension, bradycardia, and hypotension with bradycardia and nausea ± vomiting. Results Among Group I, prevalence of hypotension, bradycardia, and hypotension together with bradycardia was 152 (41.83%) patients, eight (2.20%) patients, and seven (1.92%) patients, respectively. In Group II, the prevalence of hypotension, bradycardia, and hypotension with bradycardia was 93 (50.5%) patients, five (2.71%) patients, and six (3.2%) patients, respectively. The difference between the two groups was statistically significant for hypotension. For Group I, 152 patients (41.87%) experienced one, 23 patients (6.33%) experienced two, and three patients (0.82%) experienced three episodes of hypotension. In Group II, 93 (50.5%), 19 (7.89%), and two (1.08%) patients experienced such episodes. The difference was significant with respect of one and two episodes. The prevalence of intraoperative nausea was 11.01% (40 patients) in Group I, whereas 11.41% (21 patients) in Group II. Intraoperative vomiting occurred in 19 patients (5.23%) of Group I and 14 patients (7.60%) of Group II. The height of the

  12. Association of Out-of-Hospital Hypotension Depth and Duration With Traumatic Brain Injury Mortality.

    PubMed

    Spaite, Daniel W; Hu, Chengcheng; Bobrow, Bentley J; Chikani, Vatsal; Barnhart, Bruce; Gaither, Joshua B; Denninghoff, Kurt R; Adelson, P David; Keim, Samuel M; Viscusi, Chad; Mullins, Terry; Rice, Amber D; Sherrill, Duane

    2017-10-01

    Out-of-hospital hypotension has been associated with increased mortality in traumatic brain injury. The association of traumatic brain injury mortality with the depth or duration of out-of-hospital hypotension is unknown. We evaluated the relationship between the depth and duration of out-of-hospital hypotension and mortality in major traumatic brain injury. We evaluated adults and older children with moderate or severe traumatic brain injury in the preimplementation cohort of Arizona's statewide Excellence in Prehospital Injury Care study. We used logistic regression to determine the association between the depth-duration dose of hypotension (depth of systolic blood pressure <90 mm Hg integrated over duration [minutes] of hypotension) and odds of inhospital death, controlling for significant confounders. There were 7,521 traumatic brain injury cases included (70.6% male patients; median age 40 years [interquartile range 24 to 58]). Mortality was 7.8% (95% confidence interval [CI] 7.2% to 8.5%) among the 6,982 patients without hypotension (systolic blood pressure ≥90 mm Hg) and 33.4% (95% CI 29.4% to 37.6%) among the 539 hypotensive patients (systolic blood pressure <90 mm Hg). Mortality was higher with increased hypotension dose: 0.01 to 14.99 mm Hg-minutes 16.3%; 15 to 49.99 mm Hg-minutes 28.1%; 50 to 141.99 mm Hg-minutes 38.8%; and greater than or equal to 142 mm Hg-minutes 50.4%. Log2 (the logarithm in base 2) of hypotension dose was associated with traumatic brain injury mortality (adjusted odds ratio 1.19 [95% CI 1.14 to 1.25] per 2-fold increase of dose). In this study, the depth and duration of out-of-hospital hypotension were associated with increased traumatic brain injury mortality. Assessments linking out-of-hospital blood pressure with traumatic brain injury outcomes should consider both depth and duration of hypotension. Copyright © 2017 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.

  13. Chronic elevation of IL-1β induces diuresis via a cyclooxygenase 2-mediated mechanism.

    PubMed

    Boesen, E I

    2013-07-15

    Chronic renal inflammation is an increasingly recognized phenomenon in multiple disease states, but the impact of specific cytokines on renal function is unclear. Previously, we found that 14-day interleukin-1β (IL-1β) infusion increased urine flow in mice. To determine the mechanism by which this occurs, the current study tested the possible involvement of three classical prodiuretic pathways. Chronic IL-1β infusion significantly increased urine flow (6.5 ± 1 ml/day at day 14 vs. 2.3 ± 0.3 ml/day in vehicle group; P < 0.05) and expression of cyclooxygenase (COX)-2, all three nitric oxide synthase (NOS) isoforms, and endothelin (ET)-1 in the kidney (P < 0.05 in all cases). Urinary prostaglandin E metabolite (PGEM) excretion was also significantly increased at day 14 of IL-1β infusion (1.21 ± 0.26 vs. 0.29 ± 0.06 ng/day in vehicle-infused mice; P = 0.001). The selective COX-2 inhibitor celecoxib markedly attenuated urinary PGEM excretion and abolished the diuretic response to chronic IL-1β infusion. In contrast, deletion of NOS3, or inhibition of NOS1 with L-VNIO, did not blunt the diuretic effect of IL-1β, nor did pharmacological blockade of endothelin ETA and ETB receptors with A-182086. Consistent with a primary effect on water transport, IL-1β infusion markedly reduced inner medullary aquaporin-2 expression (P < 0.05) and did not alter urinary Na⁺ or K⁺ excretion. These data indicate a critical role for COX-2 in mediating the effects of chronic IL-1β elevation on the kidney.

  14. Do we need to evaluate diastolic blood pressure in patients with suspected orthostatic hypotension?

    PubMed

    Fedorowski, Artur; Hamrefors, Viktor; Sutton, Richard; van Dijk, J Gert; Freeman, Roy; Lenders, Jacques Wm; Wieling, Wouter

    2017-06-01

    The contribution of diastolic blood pressure measurement to the diagnosis of classical orthostatic hypotension is not known. We aimed to explore the prevalence of isolated systolic and diastolic orthostatic hypotension components in patients with syncope and orthostatic intolerance. A total of 1520 patients aged >15 years with suspected syncope and/or symptoms of orthostatic intolerance were investigated in a tertiary center using tilt-table testing and continuous non-invasive blood pressure monitoring. Classical orthostatic hypotension was defined as a decline in systolic blood pressure ≥20 mmHg and/or diastolic blood pressure ≥10 mmHg at 3 min of tilt test. The prevalence of upright systolic blood pressure <90 mmHg and its overlap with isolated diastolic orthostatic hypotension was also assessed. One hundred eighty-six patients (12.2%) met current diagnostic criteria for classical orthostatic hypotension. Of these, 176 patients (94.6%) met the systolic criterion and 102 patients (54.8%) met the diastolic criterion. Ninety-two patients (49.5%) met both systolic and diastolic criteria, whereas ten patients (5.4%) met the diastolic criterion alone. Of these, three had systolic blood pressure <90 mmHg during tilt test and were diagnosed with orthostatic hypotension on the grounds of low standing blood pressure. Based on patient history and ancillary test results, causes of orthostatic intolerance and syncope other than orthostatic hypotension were present in the remaining seven patients. An abnormal orthostatic fall in diastolic blood pressure without an abnormal fall in systolic blood pressure is rare among patients with syncope and orthostatic intolerance. Approximately 95% of patients with classical orthostatic hypotension can be identified by systolic criterion alone.

  15. Is refractory hypotension in preterm infants a manifestation of early ductal shunting?

    PubMed

    Sarkar, S; Dechert, R; Schumacher, R E; Donn, S M

    2007-06-01

    Clinicians frequently use hydrocortisone (HC) to treat vasopressor-resistant hypotension even before establishing its cause. To identify the etiologic factors leading to development of refractory hypotension, and to assess if patent ductus arteriosus (PDA) is associated with refractory hypotension during the first week of life. The medical records of 290 consecutively born infants hypotension was defined as MABP unresponsive to fluid boluses and high-dose vasopressors (dopamine and dobutamine at doses 20 microg/kg/min each and/or epinephrine) prompting the use of HC. Eighty-nine (30.7%) of 290 infants had refractory hypotension between postnatal days 2 and 7. Infants with refractory hypotension were more likely to have a lower birth weight and GA (P<0.001), been treated with surfactant (P=0.004) and received indomethacin for a symptomatic PDA (P<0.001). To identify the etiologic factors, a univariate analysis revealed that the use of high-frequency oscillatory ventilation, presence of air leaks, PDA, sepsis, hyperkalemia and intraventricular hemorrhage (IVH) were significantly associated with refractory hypotension. However, multivariate analysis confirmed the independent association of only PDA (odds ratio (OR) 7.6, 95% confidence interval (CI) 3.3-17.7, P=0.000), severe IVH (OR 2.6, 95% CI 1.1-6.4, P=0.03) and GA (OR 0.7, 95% CI 0.6-0.8, P=0.001). Evaluation for early ductal shunting and closure of the ductus, if patent, should be attempted before HC is considered in hypotensive infants with escalating needs for vasopressors.

  16. Non-invasive haemodynamic measurements with Nexfin predict the risk of hypotension following spinal anaesthesia.

    PubMed

    Ławicka, Marzena; Małek, Andrzej; Antczak, Damian; Wajlonis, Anita; Owczuk, Radosław

    2015-01-01

    Unfavourable circulatory system conditions have been observed in many patients with spinal anaesthesia. The most frequent symptoms include a decrease in blood pressure and, less frequently, bradycardia. The appearance of unfavourable consequences of spinal anaesthesia might be related to the initial status of the patient's circulatory system. The aim of this study was to establish the possibility of predicting unfavourable circulatory consequences (hypotension, bradycardia) following spinal anaesthesia, based on non-invasive haemodynamic assessment with a Nexfin device. This prospective study included 100 18-60-year-old ASA I or II planned spinal anaesthesia patients. The initial hemodynamic parameters were assessed with a Nexfin monitor. Anaesthesia was performed with 3-3.5 mL of a 0,5% hyperbaric bupivacaine solution. Within 20 min after the administration of anaesthesia, the arterial blood pressure values, heart rate, sensory blockade level, and motoric blockade level were recorded in 5-min intervals. Hypotension was classified by a decrease of SAP < 90 mm Hg and/or the decrease of the SAP ≥ 20% initial value. Logistic regression was used to determine the independent predictors of hypotension resulting from a spinal blockade. The development of hypotension and bradycardia was observed in 39 and 2%, respectively, of the patients. The patients who developed hypotension differed significantly from those who did not develop this symptom, with the main difference being the body mass and the assessment on the ASA scale. The patients who developed hypotension after spinal anaesthesia differed significantly in the initial hemodynamic parameters (SAP, MAP, SVRI). The following two independent risk factors for hypotension were isolated: the mean arterial pressure (OR 1.04; 95% CI: 1.005-1.076) and the systemic vascular resistance index (OR 1.109; 95% CI: 1.021-1.204). Nexfin-based non-invasive haemodynamic monitoring might be helpful in the identification of individuals

  17. Incidence of and Risk Factors For Post-Intubation Hypotension in the Critically Ill.

    PubMed

    Smischney, Nathan J; Demirci, Onur; Diedrich, Daniel A; Barbara, David W; Sandefur, Benjamin J; Trivedi, Sangita; McGarry, Sean; Kashyap, Rahul

    2016-02-02

    We aim to report the incidence of post-intubation hypotension in the critically ill, to report in-hospital mortality and length of stay in those who developed post-intubation hypotension, and to explore possible risk factors associated with post-intubation hypotension. Adult (≥18 years) ICU patients who received emergent endotracheal intubation were included. We excluded patients if they were hemodynamically unstable 60 minutes pre-intubation. Post-intubation hypotension was defined as the administration of any vasopressor within 60 minutes following intubation. Twenty-nine patients developed post-intubation hypotension (29/147, 20%). Post-intubation hypotension was associated with increased in-hospital mortality (11/29, 38% vs. 19/118, 16%) and length of stay (21 [10-37] vs. 12 [7-21] days) on multivariate analysis. Three risk factors for post-intubation hypotension were identified on multivariate analysis: 1) decreasing mean arterial pressure pre-intubation (per 5 mmHg decrease) (p-value=0.04; 95% CI 1.01-1.55); 2) administration of neuromuscular blockers (p-value=0.03; 95% CI 1.12-6.53); and 3) intubation complication (p-value=0.03; 95% CI 1.16-15.57). Post-intubation hypotension was common in the ICU and was associated with increased in-hospital mortality and length of stay. These patients were more likely to have had lower mean arterial pressure prior to intubation, received neuromuscular blockers, or suffered a complication during intubation.

  18. Incidence of and Risk Factors For Post-Intubation Hypotension in the Critically Ill

    PubMed Central

    Smischney, Nathan J.; Demirci, Onur; Diedrich, Daniel A.; Barbara, David W.; Sandefur, Benjamin J.; Trivedi, Sangita; McGarry, Sean; Kashyap, Rahul

    2016-01-01

    Background We aim to report the incidence of post-intubation hypotension in the critically ill, to report in-hospital mortality and length of stay in those who developed post-intubation hypotension, and to explore possible risk factors associated with post-intubation hypotension. Material/Methods Adult (≥18 years) ICU patients who received emergent endotracheal intubation were included. We excluded patients if they were hemodynamically unstable 60 minutes pre-intubation. Post-intubation hypotension was defined as the administration of any vasopressor within 60 minutes following intubation. Results Twenty-nine patients developed post-intubation hypotension (29/147, 20%). Post-intubation hypotension was associated with increased in-hospital mortality (11/29, 38% vs. 19/118, 16%) and length of stay (21 [10–37] vs. 12 [7–21] days) on multivariate analysis. Three risk factors for post-intubation hypotension were identified on multivariate analysis: 1) decreasing mean arterial pressure pre-intubation (per 5 mmHg decrease) (p-value=0.04; 95% CI 1.01–1.55); 2) administration of neuromuscular blockers (p-value=0.03; 95% CI 1.12–6.53); and 3) intubation complication (p-value=0.03; 95% CI 1.16–15.57). Conclusions Post-intubation hypotension was common in the ICU and was associated with increased in-hospital mortality and length of stay. These patients were more likely to have had lower mean arterial pressure prior to intubation, received neuromuscular blockers, or suffered a complication during intubation. PMID:26831818

  19. Progressively invalidating orthostatic hypotension: A common symptom for a challenging diagnosis

    PubMed Central

    Pelusi, Serena; Lombardi, Rosa; Airaghi, Lorena; Burdick, Larry; Rango, Mario; Penatti, Alessandra; Fargion, Silvia

    2016-01-01

    We discuss here an uncommon condition of neurogenic hypotension in the context of immunoglobulin light chain (amyloid light-chain) amyloidosis. The most serious feature was autonomic nervous system impairment, mainly characterized by severe refractory orthostatic hypotension, which became progressively invalidating, forcing the patient to bed. Moreover, since the systemic involvement of the disease, the patient presented also diarrhea, dysphagia, asthenia, peripheral edema because of gastrointestinal, and kidney dysfunction. Eventually, the massive myocardial depression and infiltration led to a fatal outcome. PMID:28255325

  20. A case of protracted hypotension as unique symptom of a biphasic anaphylaxis to amoxicillin.

    PubMed

    Zisa, G; Riccobono, F; Calamari, A M; D'Antonio, C D; Galimberti, M

    2009-04-01

    We are reporting a case of one patient who have experienced itching of palms and soles, thorax erythema, conjunctive injection immediately after oral administration of amoxicillin, and hypotension after 3 hours. In E.D. hypotension was monitored because he was a cardiopatic but it wasn't treated even if it was protracted. A positive result of immediate-reading intradermal test with amoxicillin at 2 mg/ml concentration was found confirming the diagnosis of allergic biphasic anaphylaxis to amoxicillin.

  1. Research pilot Mark Pestana

    NASA Image and Video Library

    2001-04-16

    Mark Pestana is a research pilot and project manager at the NASA Dryden Flight Research Center, Edwards, Calif. He is a pilot for the Beech B200 King Air, the T-34C and the Predator B. He flies the F-18 Hornet as a co-pilot and flight test engineer. Pestana has accumulated more than 4,000 hours of military and civilian flight experience. He was also a flight engineer on the NASA DC-8 flying laboratory. Pestana was the project manager and pilot for the Hi–rate Wireless Airborne Network Demonstration flown on the NASA B200 research aircraft. He flew B200 research missions for the X-38 Space Integrated Inertial Navigation Global Positioning System experiment. Pestana also participated in several deployments of the DC-8, including Earth science expeditions ranging from hurricane research over the Caribbean Sea to ozone studies over the North Pole, atmospheric chemistry over the South Pacific, rain forest health in Central America, Rocky Mountain ice pack assessment, and volcanic and tectonic activity around the Pacific Rim. He came to Dryden as a DC-8 mission manager in June 1998 from NASA Johnson Space Center, Houston, where he served as the Earth and Space Science discipline manager for the International Space Station Program at Johnson. Pestana also served as a flight crew operations engineer in the Astronaut Office, developing the controls, displays, tools, crew accommodations and procedures for on-orbit assembly, test, and checkout of the International Space Station. He led the analysis and technical negotiations for modification of the Russian Soyuz spacecraft as an emergency crew return vehicle for space station crews. He joined the U.S. Air Force Reserve in 1991 and held various positions as a research and development engineer, intelligence analyst, and Delta II launch vehicle systems engineer. He retired from the U.S. Air Force Reserve with the rank of colonel in 2005. Prior to 1990, Pestana was on active duty with the U.S. Air Force as the director of mi

  2. Increased diuresis, renal vascular reactivity, and blood pressure levels in young rats fed high sodium, moderately high fructose, or their association: a comparative evaluation.

    PubMed

    Da Silva, Rita de Cássia Vilhena A F; de Souza, Priscila; da Silva-Santos, José Eduardo

    2016-12-01

    Excessive intakes of sodium or fructose have been described as risk factors for hypertension. We hypothesized that even a moderately high fructose diet (6% fructose), either alone or in combination with high sodium (4% NaCl), may impair diuresis and renal and systemic vascular reactivity, contributing to the onset of high blood pressure in rats. Male Wistar rats were fed chow containing 4% NaCl (HS), 6% fructose (MHF), or both 4% NaCl and 6% fructose (HSMHF) for 6 weeks and had their diuresis, plasma creatinine, vascular reactivity of perfused kidneys and systemic arterial pressure evaluated. We found no differences in augmented diuresis among animals given HS, MHF, or HSMHF diets. After 6 weeks both the HS and HSMHF groups had increased weight in their left kidneys, but only the HSMHF group showed augmented plasma creatinine. The effects of phenylephrine on renal vascular perfusion pressure were similarly enhanced in kidneys from the HS, MHF, and HSMHF groups, but not on the systemic arterial pressure. Although when evaluated in anesthetized rats, only the HSMHF group presented augmented blood pressure, evaluation in conscious animals revealed that both the MHF and HSMHF diets, but not the HS alone, were able to induce tachycardia and hypertension. In conclusion, a MHF diet containing 6% fructose was enough to render the renal vascular bed hyperreactive to phenylephrine and to induce both hypertension and tachycardia. The combination of 6% fructose with 4% NaCl led to plasma accumulation of creatinine and accelerated the development of tachycardia.

  3. Activation of the contact system in lethal hypotensive bacteremia in a baboon model.

    PubMed Central

    Pixley, R. A.; DeLa Cadena, R. A.; Page, J. D.; Kaufman, N.; Wyshock, E. G.; Colman, R. W.; Chang, A.; Taylor, F. B.

    1992-01-01

    The hypotension in septicemia is believed to be mediated by the combined action of many mediators including cytokines, prostaglandins, and complement components. To evaluate the contribution of the contact/kinin-forming system to hypotension, the authors used an established experimental baboon model of bacteremia in which two concentrations of Escherichia Coli (E. coli) were used to produce lethal and nonlethal hypotension. The lethal group (n = 5) developed irreversible hypotension that significantly correlated with the decline in levels of high molecular weight kininogen (HK) and an increase in alpha 2 macroglobulin-kallikrein complexes (alpha 2M-kal). The nonlethal group (n = 9) experienced reversible hypotension, a less striking decline in HK, and only slight elevation in alpha 2M-kal. No significant changes were found in levels of factor XII, prekallikrein, and factor XI in either group. A significant change in the contact system, which reflects the fatal outcome, is the rise in alpha 2M-kal. This study suggests that irreversible hypotension correlates with prolonged activation of the contact system. PMID:1373271

  4. Vascular contractile reactivity in hypotension due to reduced renal reabsorption of Na(+) and restricted dietary Na().

    PubMed

    Alshahrani, Saeed; Rapoport, Robert M; Soleimani, Manoocher

    2017-03-01

    Reduced renal Na(+) reabsorption along with restricted dietary Na(+) depletes intravascular plasma volume which can then result in hypotension. Whether hypotension occurs and the magnitude of hypotension depends in part on compensatory angiotensin II-mediated increased vascular resistance. We investigated whether the ability of vascular resistance to mitigate the hypotension was compromised by decreased contractile reactivity. In vitro reactivity was investigated in aorta from mouse models of reduced renal Na(+) reabsorption and restricted dietary Na(+) associated with considerable hypotension and renin-angiotensin system activation: (1) the Na(+)-Cl(-)-Co-transporter (NCC) knockout (KO) with Na(+) restricted diet (0.1%, 2 weeks) and (2) the relatively more severe pendrin (apical chloride/bicarbonate exchanger) and NCC double KO. Contractile sensitivity to KCl, phenylephrine, and/or U46619 remained unaltered in aorta from both models. Maximal KCl and phenylephrine contraction expressed as force/aorta length from NCC KO with Na(+)-restricted diet remained unaltered, while in pendrin/NCC double KO were reduced to 49 and 64%, respectively. Wet weight of aorta from NCC KO with Na(+)-restricted diet remained unaltered, while pendrin/NCC double KO was reduced to 67%, consistent with decreased medial width determined with Verhoeff-Van Gieson stain. These findings suggest that hypotension associated with severe intravascular volume depletion, as the result of decreased renal Na(+) reabsorption, may in part be due to decreased contractile reactivity as a consequence of reduced vascular hypertrophy.

  5. Accuracy and Precision of Noninvasive Blood Pressure in Normo-, Hyper-, and Hypotensive Standing and Anesthetized Adult Horses.

    PubMed

    Heliczer, N; Lorello, O; Casoni, D; Navas de Solis, C

    2016-05-01

    Blood pressure is relevant to the diagnosis and management of many medical, cardiovascular and critical diseases. The accuracy of many commonly used noninvasive blood pressure (NIBP) monitors and the accuracy of NIBP measurements in hypo- and hypertensive standing horses has not been determined. The objective of this study was to investigate the accuracy of an oscillometric BP monitor in standing horses before and during pharmacologically induced hyper- and hypotension and to compare results in standing and anesthetized horses. Eight standing mares from a research herd (SG) and eight anesthetized horses from a hospital population (AG). Prospective experimental and observational studies. Invasive blood pressure (IBP) and NIBP, corrected to heart level, were measured simultaneously. In the SG hyper- and hypotension were induced by administration of phenylephrine (3 μg/kg/min IV for 15 minutes) and acepromazine (0.05 mg/kg IV), respectively. In the AG NIBP and IBP were recorded during regular hospital procedures. There was a significant correlation between mean NIBP and IBP in standing (R = 0.88, P < .001) and anesthetized horses (R = 0.81, P < .001). The mean bias (lower, upper limit of agreement) was 16.4(-16.1, 48.9) mmHg for mean BP in the SG and 0.5(-22.3, 23.2) mmHg in the AG. The NIBP device was capable of identifying the increase and decrease in BP in all horses, but in the SG significant correlation between NIBP and IBP was only detected for the normotensive phase. While the evaluated oscillometric BP device allowed estimation of BP and adequately differentiated marked trends, the accuracy and precision were low in standing horses. Copyright © 2016 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

  6. Diuresis and reduced urinary osmolality in rats produced by small-molecule UT-A-selective urea transport inhibitors.

    PubMed

    Esteva-Font, Cristina; Cil, Onur; Phuan, Puay-Wah; Su, Tao; Lee, Sujin; Anderson, Marc O; Verkman, A S

    2014-09-01

    Urea transport (UT) proteins of the UT-A class are expressed in epithelial cells in kidney tubules, where they are required for the formation of a concentrated urine by countercurrent multiplication. Here, using a recently developed high-throughput assay to identify UT-A inhibitors, a screen of 50,000 synthetic small molecules identified UT-A inhibitors of aryl-thiazole, γ-sultambenzosulfonamide, aminocarbonitrile butene, and 4-isoxazolamide chemical classes. Structure-activity analysis identified compounds that inhibited UT-A selectively by a noncompetitive mechanism with IC50 down to ∼1 μM. Molecular modeling identified putative inhibitor binding sites on rat UT-A. To test compound efficacy in rats, formulations and administration procedures were established to give therapeutic inhibitor concentrations in blood and urine. We found that intravenous administration of an indole thiazole or a γ-sultambenzosulfonamide at 20 mg/kg increased urine output by 3-5-fold and reduced urine osmolality by ∼2-fold compared to vehicle control rats, even under conditions of maximum antidiuresis produced by 1-deamino-8-D-arginine vasopressin (DDAVP). The diuresis was reversible and showed urea > salt excretion. The results provide proof of concept for the diuretic action of UT-A-selective inhibitors. UT-A inhibitors are first in their class salt-sparing diuretics with potential clinical indications in volume-overload edemas and high-vasopressin-associated hyponatremias.

  7. Chloride channels in stellate cells are essential for uniquely high secretion rates in neuropeptide-stimulated Drosophila diuresis.

    PubMed

    Cabrero, Pablo; Terhzaz, Selim; Romero, Michael F; Davies, Shireen A; Blumenthal, Edward M; Dow, Julian A T

    2014-09-30

    Epithelia frequently segregate transport processes to specific cell types, presumably for improved efficiency and control. The molecular players underlying this functional specialization are of particular interest. In Drosophila, the renal (Malpighian) tubule displays the highest per-cell transport rates known and has two main secretory cell types, principal and stellate. Electrogenic cation transport is known to reside in the principal cells, whereas stellate cells control the anion conductance, but by an as-yet-undefined route. Here, we resolve this issue by showing that a plasma membrane chloride channel, encoded by ClC-a, is exclusively expressed in the stellate cell and is required for Drosophila kinin-mediated induction of diuresis and chloride shunt conductance, evidenced by chloride ion movement through the stellate cells, leading to depolarization of the transepithelial potential. By contrast, ClC-a knockdown had no impact on resting secretion levels. Knockdown of a second CLC gene showing highly abundant expression in adult Malpighian tubules, ClC-c, did not impact depolarization of transepithelial potential after kinin stimulation. Therefore, the diuretic action of kinin in Drosophila can be explained by an increase in ClC-a-mediated chloride conductance, over and above a resting fluid transport level that relies on other (ClC-a-independent) mechanisms or routes. This key segregation of cation and anion transport could explain the extraordinary fluid transport rates displayed by some epithelia.

  8. [The effect of niaoduqing tablet on the diuresis in normal rats and the hemorheology in blood-stasis rats].

    PubMed

    Deng, Hong-zhu; Xiao, Wei; Chen, Yu-yao

    2003-03-01

    To observe the effect of the Niaoduqing Tablet(NDT) on the diuresis in normal rats and the hemorheology in rats of blood stasis and compare it with the Niaoduqing Granule(NDG), so as to provide some laboratory data for the clinic application and innovation of the dosage forms. Diuretic effect of the NDT on experimental rats burthened with 1% Sodium deoxycholate was observed by using the metabolize cage examination. The changes of whole blood and plasma viscosity in the blood-stasis rat-model were measured with Viscometer-R80. Plasma was separated and fibrinogen measured by using the turbidimetric method. Every dose of NDT had the diuretic effect on experiment rats, but only the big and middle dose increasing the urine quantity in 6 hours had the significance. Each dose could reduce the viscosity of whole blood and the fibrinogen in the blood-stasis rat model, and had the superiority to NDG. NDT has the diuretic effect and can ameliorate the hemorheology in the blood-stasis rat model, which may delay the course of the chronic renal failure (CRF).

  9. Caffeine-induced natriuresis and diuresis via blockade of hepatic adenosine-mediated sensory nerves and a hepatorenal reflex.

    PubMed

    Ming, Zhi; Lautt, W Wayne

    2010-11-01

    The hepatorenal reflex, activated by intrahepatic adenosine, is involved in the regulation of urine production in healthy rats and renal pathogenesis secondary to liver injury. Hepatic adenosine A1 receptors regulate the hepatorenal reflex. The aim of the present study was to evaluate whether caffeine mediates renal natriuresis and diuresis in healthy and diseased liver through this mechanism. Rats were anesthetized and instrumented to monitor systemic, hepatic, and renal circulation and urine production. Intrahepatic (intraportal but not intravenous) caffeine (5 mg·kg-1) increased urine flow (~82%) in healthy rats. This effect was abolished by liver denervation. Intraportal infusion of adenosine decreased urine production, and this response was abolished by intraportal but not intravenous caffeine. Liver injury was induced by intraperitoneal injection of thioacetamide (500 mg·kg-1), and functional assessment was performed 24 h later. Liver injury was associated with lower (~30%) glomerular filtration rate, lower (~18%) renal arterial blood flow, and lower urine production. Intraportal but not intravenous caffeine improved basal urine production and renal ability to increase urine production in response to saline overload. The liver-dependent diuretic effect of caffeine is consistent with the hypothesis for the adenosine-mediated mechanism of hepatorenal syndrome.

  10. Artemisia copa aqueous extract as vasorelaxant and hypotensive agent.

    PubMed

    Gorzalczany, Susana; Moscatelli, Valeria; Ferraro, Graciela

    2013-06-21

    Artemisia copa Phil. (Asteraceae) is a medicinal plant commonly used in traditional medicine in Argentina. The vasorelaxant and hypotensive activities of the aqueous extract of Artemisia copa have been investigated. The in vitro effect of the extract and isolated compounds from Artemisia copa was investigated using isolated rat aortic rings. The acute effect caused by the intravenous (i.v.) infusion (0.1-300mg/kg) on blood pressure and heart rate was evaluated in spontaneous hypertensive rats. In addition, a phytochemical analysis of the extract was performed by HPLC. Artemisia copa had a relaxant effect in endothelium-intact aortic rings that had been pre-contracted with 10(-7)M phenylephrine (Emax=96.7±1.3%, EC50=1.1mg/ml), 10(-5)M 5-hydroxytriptamine (Emax=96.7±3.5%, EC50=1.5mg/ml) and 80mM KCl (Emax=97.9± 4.4%, EC50=1.6mg/ml). In denuded aortic rings contracted by phenylephrine, a similar pattern was observed (Emax=92.7±6.5%, EC50=1.8mg/ml). l-NAME, indomethacin, tetraethylammonium and glibenclamide were not able to block the relaxation induced by the extract. Nevertheless, the pre-treatment with Artemisia copa attenuated the CaCl2-induced contraction in a concentration-dependent manner (Emax: 86% of inhibition for 3mg/ml and 52% de-inhibition for 1mg/ml). This pre-treatment also induced a significant attenuation of the norepinephrine-induced contraction in a concentration-dependent manner (Emax: 72.7% of inhibition for 3mg/ml and 27% de inhibition for 1mg/ml) in a Ca(2+) free medium. Upon analyzing the composition of the extract, the presence of p-coumaric acid, isovitexin, luteolin and chrysoeriol were found. Luteolin (CE50: 1.5μg/ml), chrysoeriol (CE50: 13.2μg/ml) and p-coumaric acid (CE50: 95.2μg/ml), isolated from the aqueous extract, caused dilatation of thoracic aortic rings pre-contracted with phenylephrine. Artemisia copa administered i.v. also induced a decrease in the mean arterial pressure but did not affect the heart rate in hypertensive

  11. Autoregulation of cerebral blood flow in orthostatic hypotension

    NASA Technical Reports Server (NTRS)

    Novak, V.; Novak, P.; Spies, J. M.; Low, P. A.

    1998-01-01

    BACKGROUND AND PURPOSE: We sought to evaluate cerebral autoregulation in patients with orthostatic hypotension (OH). METHODS: We studied 21 patients (aged 52 to 78 years) with neurogenic OH during 80 degrees head-up tilt. Blood flow velocities (BFV) from the middle cerebral artery were continuously monitored with transcranial Doppler sonography, as were heart rate, blood pressure (BP), cardiac output, stroke volume, CO2, total peripheral resistance, and cerebrovascular resistance. RESULTS: All OH patients had lower BP (P<.0001), BFV_diastolic (P<.05), CVR (P<.007), and TPR (P<.02) during head-up tilt than control subjects. In control subjects, no correlations between BFV and BP were found during head-up tilt, suggesting normal autoregulation. OH patients could be separated into those with normal or expanded autoregulation (OH_NA; n=16) and those with autoregulatory failure (OH_AF; n=5). The OH_NA group showed either no correlation between BFV and BP (n=8) or had a positive BFV/BP correlation (R2>.75) but with a flat slope. An expansion of the "autoregulated" range was seen in some patients. The OH_AF group was characterized by a profound fall in BFV in response to a small reduction in BP (mean deltaBP <40 mm Hg; R2>.75). CONCLUSIONS: The most common patterns of cerebral response to OH are autoregulatory failure with a flat flow-pressure relationship or intact autoregulation with an expanded autoregulated range. The least common pattern is autoregulatory failure with a steep flow-pressure relationship. Patients with patterns 1 and 2 have an enhanced capacity to cope with OH, while those with pattern 3 have reduced capacity.

  12. Early Discontinuation of Treatment in Patients with Orthostatic Hypotension

    PubMed Central

    Shibao, C.; Grijalva, C.G.; Lipsitz, L.A.; Biaggioni, I.; Griffin, M.R.

    2014-01-01

    Background Midodrine and fludrocortisone are considered the first-line pharmacologic treatments for orthostatic hypotension (OH). Although OH is thought to require long-term therapy, it is unknown how long patients remain on treatment (“persistence”). Methods We assembled a retrospective cohort of patients with OH aged ≥50 years enrolled in Tennessee Medicaid (1996–2008), and identified new episodes of midodrine and fludrocortisone use. Follow-up continued from first medication fill through treatment discontinuation (90 days without medication), change in treatment, death, hospitalization, loss of enrollment or study end. We compared persistence on treatment using Cox regression models and fludrocortisone as reference. Covariates included demographics, healthcare utilization measurements and co-morbidities. Results We identified 1,704 OH patients, who initiated 1,767 episodes of fludrocortisone (1103) or midodrine (664) use. The median age was 69 years, 53% were female and 80% were white. During 738 person years of follow-up, episodes of use ended because of treatment discontinuation in 467 (27% fludrocortisone, 25% midodrine); treatment change in 72 (3% fludrocortisone, 6% midodrine) and death in 53 (3% fludrocortisone, 2% midodrine). Overall median persistence on fludrocortisone and midodrine was 254 (IQR: 119–783) and 259 (IQR: 119–807) days, respectively. The adjusted hazard ratio (aHR) for overall non-persistence on midodrine compared to fludrocortisone was 1.07 (95% CI: 0.90–1.28). Conclusions Overall duration of OH treatment with first-line medications was short, and similar for fludrocortisone and midodrine. Further research is warranted to determine the causes of this low persistence. PMID:24008021

  13. Orthostatic Hypotension and Mortality in Elderly Frail Patients

    PubMed Central

    Freud, Tamar; Punchik, Boris; Yan, Press

    2015-01-01

    Abstract Orthostatic hypotension (OH) is a common problem in the elderly age group, and some studies have reported an association between OH and increased mortality. We evaluated possible associations between OH and mortality in a retrospective study of frail elderly patients who came for a comprehensive geriatric assessment. The study included all patients ≥65 years who were assessed in the outpatient Comprehensive Geriatric Assessment Unit. Data were collected from the computerized medical record, including blood pressure, sociodemographic data, lifestyle, falls, pulse rate, body mass index, functional and cognitive status, and comorbidity. Data on mortlaity were also collected. The study population consisted of 571 patients who underwent assessment over a 9-year study period. The mean age was 83.7 ± 6.1, 35.9% were males, and 183 (32.1%) were diagnosed with OH. Systolic OH (OHS) was more common than diastolic OH (25.2% vs 15.6%). In univariate analyses, OHS was associated with increased overall mortality. Over the follow-up period, 30.2% of the OHS patients died compared with 22.3% (P = 0.037), but in the Cox models there was no statistically significant associations between OHS and overall mortality. In contrast, age, burden of comorbidity, a low high-density lipoprotein level, and low creatinine clearance were independent predictors of increased overall mortality. In a population of frail elderly patients with a high burden of comorbidity, OH was not an independent risk factor for overall mortality. PMID:26091470

  14. Autoregulation of cerebral blood flow in orthostatic hypotension

    NASA Technical Reports Server (NTRS)

    Novak, V.; Novak, P.; Spies, J. M.; Low, P. A.

    1998-01-01

    BACKGROUND AND PURPOSE: We sought to evaluate cerebral autoregulation in patients with orthostatic hypotension (OH). METHODS: We studied 21 patients (aged 52 to 78 years) with neurogenic OH during 80 degrees head-up tilt. Blood flow velocities (BFV) from the middle cerebral artery were continuously monitored with transcranial Doppler sonography, as were heart rate, blood pressure (BP), cardiac output, stroke volume, CO2, total peripheral resistance, and cerebrovascular resistance. RESULTS: All OH patients had lower BP (P<.0001), BFV_diastolic (P<.05), CVR (P<.007), and TPR (P<.02) during head-up tilt than control subjects. In control subjects, no correlations between BFV and BP were found during head-up tilt, suggesting normal autoregulation. OH patients could be separated into those with normal or expanded autoregulation (OH_NA; n=16) and those with autoregulatory failure (OH_AF; n=5). The OH_NA group showed either no correlation between BFV and BP (n=8) or had a positive BFV/BP correlation (R2>.75) but with a flat slope. An expansion of the "autoregulated" range was seen in some patients. The OH_AF group was characterized by a profound fall in BFV in response to a small reduction in BP (mean deltaBP <40 mm Hg; R2>.75). CONCLUSIONS: The most common patterns of cerebral response to OH are autoregulatory failure with a flat flow-pressure relationship or intact autoregulation with an expanded autoregulated range. The least common pattern is autoregulatory failure with a steep flow-pressure relationship. Patients with patterns 1 and 2 have an enhanced capacity to cope with OH, while those with pattern 3 have reduced capacity.

  15. 'Non-hypotensive' hypovolaemia reduces ascending aortic dimensions in humans

    NASA Technical Reports Server (NTRS)

    Taylor, J. A.; Halliwill, J. R.; Brown, T. E.; Hayano, J.; Eckberg, D. L.

    1995-01-01

    1. The notion that small, 'non-hypotensive' reductions of effective blood volume alter neither arterial pressure nor arterial baroreceptor activity is pervasive in the experimental literature. We tested two hypotheses: (a) that minute arterial pressure and cardiac autonomic outflow changes during hypovolaemia induced by lower body suction in humans are masked by alterations in breathing, and (b) that evidence for arterial baroreflex engagement might be obtained from measurements of thoracic aorta dimensions. 2. In two studies, responses to graded lower body suction at 0 (control), 5, 10, 15, 20 and 40 mmHg were examined in twelve and ten healthy young men, respectively. In the first, arterial pressure (photoplethysmograph), R-R interval, and respiratory sinus arrhythmia amplitude (complex demodulation) were measured during uncontrolled and controlled breathing (constant breathing frequency and tidal volume). In the second, cross-sectional areas of the ascending thoracic aorta were calculated from nuclear magnetic resonance images. 3. Lower body suction with controlled breathing resulted in an increased arterial pulse pressure at mild levels (5-20 mmHg; ANOVA, P < 0.05) and a decreased arterial pulse pressure at moderate levels (40 mmHg; ANOVA, P < 0.05). Both R-R intervals and respiratory sinus arrhythmia were negatively related to lower body suction level, whether group averages (general linear regression, r > 0.92) or individual subjects (orthogonal polynomials, 12 of 12 subjects) were assessed. 4. Aortic pulse area decreased progressively and significantly during mild lower body suction, with 47% of the total decline occurring by 5 mmHg. 5. These results suggest that small reductions of effective blood volume reduce aortic baroreceptive areas and trigger haemodynamic adjustments which are so efficient that alterations in arterial pressure escape detection by conventional means.

  16. Management of spontaneous intracranial hypotension – Transorbital ultrasound as discriminator

    PubMed Central

    Fichtner, Jens; Ulrich, Christian T; Fung, Christian; Knüppel, Christin; Veitweber, Martina; Jilch, Astrid; Schucht, Philippe; Ertl, Michael; Schömig, Beate; Gralla, Jan; Z'Graggen, Werner J; Bernasconi, Corrado; Mattle, Heinrich P; Schlachetzki, Felix; Raabe, Andreas; Beck, Jürgen

    2016-01-01

    Objective Spontaneous intracranial hypotension (SIH) is most commonly caused by cerebrospinal fluid (CSF) leakage. Therefore, we hypothesised that patients with orthostatic headache (OH) would show decreased optic nerve sheath diameter (ONSD) during changes from supine to upright position. Methods Transorbital B-mode ultrasound was performed employing a high-frequency transducer for ONSD measurements in the supine and upright positions. Absolute values and changes of ONSD from supine to upright were assessed. Ultrasound was performed in 39 SIH patients, 18 with OH and 21 without OH, and in 39 age-matched control subjects. The control group comprised 20 patients admitted for back surgery without headache or any orthostatic symptoms, and 19 healthy controls. Results In supine position, mean ONSD (±SD) was similar in patients with (5.38±0.91 mm) or without OH (5.48±0.89 mm; p=0.921). However, in upright position, mean ONSD was different between patients with (4.84±0.99 mm) and without OH (5.53±0.99 mm; p=0.044). Furthermore, the change in ONSD from supine to upright position was significantly greater in SIH patients with OH (−0.53±0.34 mm) than in SIH patients without OH (0.05±0.41 mm; p≤0.001) or in control subjects (0.01±0.38 mm; p≤0.001; area under the curve: 0.874 in receiver operating characteristics analysis). Conclusions Symptomatic patients with SIH showed a significant decrease of ONSD, as assessed by ultrasound, when changing from the supine to the upright position. Ultrasound assessment of the ONSD in two positions may be a novel, non-invasive tool for the diagnosis and follow-up of SIH and for elucidating the pathophysiology of SIH. PMID:26285586

  17. Orthostatic Hypotension in Middle-Age and Risk of Falls.

    PubMed

    Juraschek, Stephen P; Daya, Natalie; Appel, Lawrence J; Miller, Edgar R; Windham, Beverly Gwen; Pompeii, Lisa; Griswold, Michael E; Kucharska-Newton, Anna; Selvin, Elizabeth

    2017-02-01

    One-third of older adults fall each year. Orthostatic hypotension (OH) has been hypothesized as an important risk factor for falls, but findings from prior studies have been inconsistent. We conducted a prospective study of the association between baseline OH (1987-1989) and risk of falls in the Atherosclerosis Risk in Communities (ARIC) Study. Falls were ascertained during follow-up via ICD-9 hospital discharge codes or Centers for Medicare & Medicaid Services claims data. OH was defined as a drop in systolic blood pressure (SBP) ≥20mm Hg or diastolic blood pressure (DBP) ≥10mm Hg within 2 minutes of moving from the supine to standing position. Changes in SBP or DBP during OH assessments were also examined as continuous variables. During a median follow-up of 23 years, there were 2,384 falls among 12,661 participants (mean age 54 years, 55% women, 26% black). OH was associated with risk of falls even after adjustment for demographic characteristics and other risk factors (hazard ratio (HR): 1.30; 95% confidence interval (CI): 1.10, 1.54; P = 0.002). Postural change in DBP was more significantly associated with risk of falls (HR 1.09 per -5mm Hg change in DBP; 95% CI: 1.05, 1.13; P < 0.001) than postural change in SBP (HR 1.03 per -5mm Hg change in SBP; 95% CI: 1.01, 1.05; P = 0.002). In a community-based, middle-aged population, OH, and in particular, postural change in DBP, were independent risk factors for falls over 2 decades of follow-up. Future studies are needed to examine OH thresholds associated with increased risk of falls. © American Journal of Hypertension, Ltd 2016. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  18. The clinical relevance of orthostatic hypotension in elderly patients.

    PubMed

    Hartog, Laura; Kleefstra, Nanne; Luigies, Rene; de Rooij, Sophia; Bilo, Henk; van Hateren, Kornelis

    2017-02-22

    Orthostatic hypotension (OH) is highly prevalent in old age. The impact of OH on orthostatic complaints and falling is questionable. We wondered if the consensus definition of OH plays an essential role in the accuracy and direction of the prediction of these endpoints. We aimed to explore the relation between different definitions of OH, including relative decrease of blood pressure, and orthostatic complaints and falling. A cross-sectional study was performed with 1415 participants aged ≥65 years visiting a mobile fall-prevention team. The CAREFALL Triage Instrument and data on blood pressure, orthostatic complaints and previous fall incidents were collected. Multivariate binary logistic regression analyses were performed to assess the association of different definitions of OH and orthostatic complaints or falling. Ten different definitions of OH based on different relative declines of systolic blood pressure (SBP) and diastolic blood pressure (DBP) were defined. The 2011 consensus definition of OH was not related to orthostatic complaints (Odds Ratio (OR) 1.07 (95 % Confidence Interval (CI) 0.68-1.69)) or previous fall incidents (OR 1.08 (95%CI 0.83-1.41)). A ≥ 25 % SBP decrease was significantly related to orthostatic complaints (OR 2.81 (95%CI 1.31-6.05)) and a ≥ 25 % DBP decrease was related to previous fall incidents (OR 2.56 (95%CI 1.08-6.09)). With the exception of a decrease of ≥25 % SBP or DBP, the clinical relevance of incidental OH blood pressure measurements seems very limited with respect to orthostatic complaints or fall incidents in elderly patients. Using relative decreases may be more appropriate in clinical practice. Geriatr Gerontol Int 2016; ••: ••-••. © 2017 Japan Geriatrics Society.

  19. 'Non-hypotensive' hypovolaemia reduces ascending aortic dimensions in humans

    NASA Technical Reports Server (NTRS)

    Taylor, J. A.; Halliwill, J. R.; Brown, T. E.; Hayano, J.; Eckberg, D. L.

    1995-01-01

    1. The notion that small, 'non-hypotensive' reductions of effective blood volume alter neither arterial pressure nor arterial baroreceptor activity is pervasive in the experimental literature. We tested two hypotheses: (a) that minute arterial pressure and cardiac autonomic outflow changes during hypovolaemia induced by lower body suction in humans are masked by alterations in breathing, and (b) that evidence for arterial baroreflex engagement might be obtained from measurements of thoracic aorta dimensions. 2. In two studies, responses to graded lower body suction at 0 (control), 5, 10, 15, 20 and 40 mmHg were examined in twelve and ten healthy young men, respectively. In the first, arterial pressure (photoplethysmograph), R-R interval, and respiratory sinus arrhythmia amplitude (complex demodulation) were measured during uncontrolled and controlled breathing (constant breathing frequency and tidal volume). In the second, cross-sectional areas of the ascending thoracic aorta were calculated from nuclear magnetic resonance images. 3. Lower body suction with controlled breathing resulted in an increased arterial pulse pressure at mild levels (5-20 mmHg; ANOVA, P < 0.05) and a decreased arterial pulse pressure at moderate levels (40 mmHg; ANOVA, P < 0.05). Both R-R intervals and respiratory sinus arrhythmia were negatively related to lower body suction level, whether group averages (general linear regression, r > 0.92) or individual subjects (orthogonal polynomials, 12 of 12 subjects) were assessed. 4. Aortic pulse area decreased progressively and significantly during mild lower body suction, with 47% of the total decline occurring by 5 mmHg. 5. These results suggest that small reductions of effective blood volume reduce aortic baroreceptive areas and trigger haemodynamic adjustments which are so efficient that alterations in arterial pressure escape detection by conventional means.

  20. The Mark III VLBI System

    NASA Technical Reports Server (NTRS)

    Rogers, A. E. E.; Whitney, A. R.; Levine, J. I.; Nesman, E. F.; Webber, J. C.; Hinteregger, H. F.

    1988-01-01

    Geodetic measurements have errors in centimeter range. Collection of three reports describes both equipment and results of some measurements taken with Mark III very-long-baseline interferometry (VLBI) system. Has demonstrated high accuracy over short baselines, where phase-delay measurements used. Advanced hardware, called Mark III A, developed to improve system performance and efficiency. Original Mark III hardware and III A subsystem upgrades developed as part of NASA Crustal Dynamics Project at Haystack Observatory.

  1. 46 CFR 108.661 - Unit markings: Draft marks.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... corner column, continuing to the footing or lower displacement hull. (b) The bottom of each mark must be... unit to the surface of the water, except that where a unit has a permanent appendage extending below... surface of the water. (e) In cases where draft marks are obscured due to operational constraints or...

  2. 46 CFR 108.661 - Unit markings: Draft marks.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... corner column, continuing to the footing or lower displacement hull. (b) The bottom of each mark must be... unit to the surface of the water, except that where a unit has a permanent appendage extending below... surface of the water. (e) In cases where draft marks are obscured due to operational constraints or...

  3. 46 CFR 108.661 - Unit markings: Draft marks.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... corner column, continuing to the footing or lower displacement hull. (b) The bottom of each mark must be... unit to the surface of the water, except that where a unit has a permanent appendage extending below... surface of the water. (e) In cases where draft marks are obscured due to operational constraints or...

  4. An Approach to Mark Arthropods for Mark Capture Type Research

    USDA-ARS?s Scientific Manuscript database

    A series of studies were conducted to validate methods for marking a wide variety of arthropods with inexpensive proteins for mark-capture dispersal research. The markers tested included egg albumin protein in chicken egg whites and casein protein in bovine milk. The first study qualified the effec...

  5. Improving Marking Quality through a Taxonomy of Mark Schemes

    ERIC Educational Resources Information Center

    Ahmed, Ayesha; Pollitt, Alastair

    2011-01-01

    At the heart of most assessments lies a set of questions, and those who write them must achieve "two" things. Not only must they ensure that each question elicits the kind of performance that shows how "good" pupils are at the subject, but they must also ensure that each mark scheme gives more marks to those who are…

  6. Improving Marking Quality through a Taxonomy of Mark Schemes

    ERIC Educational Resources Information Center

    Ahmed, Ayesha; Pollitt, Alastair

    2011-01-01

    At the heart of most assessments lies a set of questions, and those who write them must achieve "two" things. Not only must they ensure that each question elicits the kind of performance that shows how "good" pupils are at the subject, but they must also ensure that each mark scheme gives more marks to those who are…

  7. Renal medullary ETB receptors produce diuresis and natriuresis via NOS1.

    PubMed

    Nakano, Daisuke; Pollock, Jennifer S; Pollock, David M

    2008-05-01

    Endothelin-1 (ET-1) plays an important role in the regulation of salt and water excretion in the kidney. Considerable in vitro evidence suggests that the renal medullary ET(B) receptor mediates ET-1-induced inhibition of electrolyte reabsorption by stimulating nitric oxide (NO) production. The present study was conducted to test the hypothesis that NO synthase 1 (NOS1) and protein kinase G (PKG) mediate the diuretic and natriuretic effects of ET(B) receptor stimulation in vivo. Infusion of the ET(B) receptor agonist sarafotoxin S6c (S6c: 0.45 microg x kg(-1) x h(-1)) in the renal medulla of anesthetized, male Sprague-Dawley rats markedly increased the urine flow (UV) and urinary sodium excretion (UNaV) by 67 and 120%, respectively. This was associated with an increase in medullary cGMP content but did not affect blood pressure. In addition, S6c-induced diuretic and natriuretic responses were absent in ET(B) receptor-deficient rats. Coinfusion of N(G)-propyl-l-arginine (10 microg x kg(-1) x h(-1)), a selective NOS1 inhibitor, suppressed S6c-induced increases in UV, UNaV, and medullary cGMP concentrations. Rp-8-Br-PET-cGMPS (10 microg x kg(-1) x h(-1)) or RQIKIWFQNRRMKWKK-LRK(5)H-amide (18 microg x kg(-1) x h(-1)), a PKG inhibitor, also inhibited S6c-induced increases in UV and UNaV. These results demonstrate that renal medullary ET(B) receptor activation induces diuretic and natriuretic responses through a NOS1, cGMP, and PKG pathway.

  8. NotaMark industrial laser marking system: a new security marking technology

    NASA Astrophysics Data System (ADS)

    Moreau, Vincent G.

    2004-06-01

    Up until now, the only variable alphanumeric data which could be added to banknotes was the number, applied by means of impact typographical numbering boxes. As an additional process or an alternative to this mechanical method, a non-contact laser marking process can be used offering high quality and greater levels of flexibility. For this purpose KBA-GIORI propose an exclusive laser marking solution called NotaMark. The laser marking process NotaMark is the ideal solution for applying variable data and personalizing banknotes (or any other security documents) with a very high resolution, for extremely large production volumes. A completely integrated solution has been developed comprised of laser light sources, marking head units, and covers and extraction systems. NotaMark allows the marking of variable data by removing locally and selectively, specific printed materials leaving the substrate itself untouched. A wide range of materials has already been tested extensively. NotaMark is a new security feature which is easy to identify and difficult to counterfeit, and which complies with the standard mechanical and chemical resistance tests in the security printing industry as well as with other major soiling tests. The laser marking process opens up a whole new range of design possibilities and can be used to create a primary security feature such as numbering, or to enhance the value of existing features.

  9. Investigation of postural hypotension due to static prolonged standing in female workers.

    PubMed

    Kabe, Isamu; Tsuruoka, Hiroko; Tokujitani, Yoko; Endo, Yuichi; Furusawa, Mami; Takebayashi, Toru

    2007-07-01

    The "Just-in-Time system" improves productivity and efficiency through cost reduction while it makes workers work in a standing posture. The aim of this study was to investigate the prevalence of postural hypotension in females during prolonged standing work, and to discuss preventive methods. Twelve female static standing workers (mean age+/-standard deviation; 32+/-14 yr old), 6 male static standing workers (30+/-4 yr old), 10 female walking workers (27+/-7 yr old) and 9 female desk workers (31+/-5 yr old) in a certain telecommunications equipment manufacturing factory agreed to participate in this study. All participants received an interview with an occupational physician, and performed the standing up test before working and ambulatory blood pressure monitoring (ABPM) while working. Although the blood pressure of the standing up test did not differ among the groups, mean pulse rates on standing up significantly increased in every group. Hypotension rates in the female standing workers' group by ABPM were 9 persons of 12 participants (75%) for systolic blood pressure (SBP), and were 11 persons of 12 participants (92%) for diastolic blood pressure (DBP). There were significantly higher than those in the female desk workers' group, none of 9 participants (0%) for SBP and 2 of 9 participants (22%) for DBP. The hypotension rates both male standing and female walking worker groups did not differ. Because all 8 workers who were found to have postural hypotension by the standing up test had decreased SBP and/or DBP by ABPM, it is suggested that persons at high risk of postural hypotension during standing work could be screened by the standing up test. The mechanism of postural hypotension may be a decrease of venous return due to leg swelling, and neurocardiogenic or vasovagal response. Preventing the congestion of the lower limbs by walking, managing standing time and wearing elastic hose to keep the amount of the venous return could prevent postural hypotension

  10. A multicenter study of the point prevalence of drug-induced hypotension in the ICU.

    PubMed

    Kane-Gill, Sandra L; LeBlanc, Jaclyn M; Dasta, Joseph F; Devabhakthuni, Sandeep

    2014-10-01

    To determine the point prevalence of drug-induced hypotension episodes in critically ill patients, to assess the episodes resulting from error, and to describe how episodes are treated. Multicenter observational, 24-hour snapshot study. Forty-seven ICUs in 27 institutions located in the United States, Canada, and Singapore. A total of 688 ICU patients were evaluated. None. Patients were included in the study if they had an episode of hypotension in the 24 hours prior to the clinical pharmacists' evaluation. The definition for a hypotensive episode is either a systolic blood pressure less than 90 mm Hg or a decrease in systolic blood pressure of 30 mm Hg over a 2-hour period. Each episode of unintentional hypotension was assessed for suspected drug-related causes. When a drug-related cause was suspected, an objective assessment tool, the modified Kramer, was used to determine causality. A score of at least "possible" was considered drug induced, referred to as a "drug-related hazardous condition." A drug-related hazardous condition is the temporal gap (intermediate stage) between the identification of an adverse drug reaction and the subsequent onset of drug-induced injury, known as an "adverse drug event." Drug-induced episodes were evaluated for medication errors and treatment. One hundred fifty-eight patients experienced 204 hypotensive episodes that were considered unintentional and drug related. Common drugs implicated included propofol, fentanyl, metoprolol, lorazepam, hydralazine, and furosemide. A total of 54 episodes (26.5%) resulted from medication errors. Common error types were improper dose/quantity (46%) and prescribing (25%). A total of 56.9% episodes were treated. Many hypotensive episodes in the ICU are drug related and require treatment. A substantial portion of these episodes result from errors and are therefore preventable. This presents opportunities to improve prescribing including optimizing drug dosing to avoid possible patient harm from drug

  11. Intracranial hypotension producing reversible coma: a systematic review, including three new cases.

    PubMed

    Loya, Joshua J; Mindea, Stefan A; Yu, Hong; Venkatasubramanian, Chitra; Chang, Steven D; Burns, Terry C

    2012-09-01

    Intracranial hypotension is a disorder of CSF hypovolemia due to iatrogenic or spontaneous spinal CSF leakage. Rarely, positional headaches may progress to coma, with frequent misdiagnosis. The authors review reported cases of verified intracranial hypotension-associated coma, including 3 previously unpublished cases, totaling 29. Most patients presented with headache prior to neurological deterioration, with positional symptoms elicited in almost half. Eight patients had recently undergone a spinal procedure such as lumbar drainage. Diagnostic workup almost always began with a head CT scan. Subdural collections were present in 86%; however, intracranial hypotension was frequently unrecognized as the underlying cause. Twelve patients underwent one or more procedures to evacuate the collections, sometimes with transiently improved mental status. However, no patient experienced lasting neurological improvement after subdural fluid evacuation alone, and some deteriorated further. Intracranial hypotension was diagnosed in most patients via MRI studies, which were often obtained due to failure to improve after subdural hematoma (SDH) evacuation. Once the diagnosis of intracranial hypotension was made, placement of epidural blood patches was curative in 85% of patients. Twenty-seven patients (93%) experienced favorable outcomes after diagnosis and treatment; 1 patient died, and 1 patient had a morbid outcome secondary to duret hemorrhages. The literature review revealed that numerous additional patients with clinical histories consistent with intracranial hypotension but no radiological confirmation developed SDH following a spinal procedure. Several such patients experienced poor outcomes, and there were multiple deaths. To facilitate recognition of this treatable but potentially life-threatening condition, the authors propose criteria that should prompt intracranial hypotension workup in the comatose patient and present a stepwise management algorithm to guide the

  12. Ultrasound measurement of inferior vena cava collapse predicts propofol-induced hypotension.

    PubMed

    Au, Arthur K; Steinberg, Dean; Thom, Christopher; Shirazi, Maziar; Papanagnou, Dimitrios; Ku, Bon S; Fields, J Matthew

    2016-06-01

    Hypotension is a common side effect of propofol, but there are no reliable methods to determine which patients are at risk for significant propofol-induced hypotension (PIH). Ultrasound has been used to estimate volume status by visualization of inferior vena cava (IVC) collapse. This study explores whether IVC assessment by ultrasound can assist in predicting which patients may experience significant hypotension. This was a prospective observational study conducted in the operating suite of an urban community hospital. A convenience sample of consenting adults planned to receive propofol for induction of anesthesia during scheduled surgical procedures were enrolled. Bedside ultrasound was used to measure maximum (IVCmax) and minimum (IVCmin) IVC diameters. IVC-CI was calculated as [(IVCmax-IVCmin)/IVCmax × 100%]. The primary outcome was significant hypotension defined as systolic blood pressure (BP) below 90mmHg and/or administration of a vasopressor to increase BP during surgery. The study sample comprised 40 patients who met inclusion criteria. Mean age was 55years, (95%CI, 49-60) with 53% female. 55% of patients had significant hypotension after propofol administration. 76% of patients with IVC-CI≥50% had significant hypotension compared to 39% with IVC-CI<50%, P=.02. IVC-CI≥50% had a specificity of 77.27% (95%CI, 64.29%-90.26%) and sensitivity of 66.67% (95%CI, 52.06%-81.28%) in predicting PIH. The odds ratio for PIH in patients with IVC-CI≥50% was 6.9 (95%CI, 1.7-27.5). Patients with IVC-CI≥50% were more likely to develop significant hypotension from propofol. IVC ultrasound may be a useful tool to predict which patients are at increased risk for PIH. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Prominent Inferior Intercavernous Sinus on Sagittal T1-Weighted Images: A Sign of Intracranial Hypotension.

    PubMed

    Alcaide-Leon, Paula; López-Rueda, Antonio; Coblentz, Ailish; Kucharczyk, Walter; Bharatha, Aditya; de Tilly, Lyne Noël

    2016-04-01

    The purpose of this study is to describe the diagnostic accuracy of the dilatation of the inferior intercavernous sinus as a sign of intracranial hypotension and to raise awareness of this anatomic structure, which can be mistaken for a focal pituitary lesion. Sagittal T1-weighted images of 26 patients with intracranial hypotension and 28 control subjects were evaluated to determine the presence of a distended inferior intercavernous sinus. Information about the shape, size, and signal of the inferior intercavernous sinus was also collected. The chi-square test was used to compare both groups. Sensitivity and specificity of the dilatation of the inferior intercavernous sinus as a sign of intracranial hypotension were calculated. A visible inferior intercavernous sinus was found in 13 of 26 patients with intracranial hypotension (50%) and in four of 28 control subjects (14.3%). These percentages were significantly different (p = 0.005). There was no significant difference in size of the inferior intercavernous sinus in the intracranial hypotension group (median, 5.86 mm(2); interquartile range, 6.28 mm(2)) compared with the control group (median, 8.25 mm(2); interquartile range, 16.69 mm(2)). Changes in the size of the inferior intercavernous sinus were detected in congruence with the appearance or resolution of intracranial hypotension. Dilatation of the inferior intercavernous sinus is frequently associated with intracranial hypotension, although it can also be found in the healthy adult as a normal anatomic variant. Recognition of this anatomic structure is important to avoid mistaking it for a focal pituitary lesion.

  14. Adrenomedullin Prevents Sex-Dependent Impairment of Autoregulation during Hypotension after Piglet Brain Injury through Inhibition of ERK MAPK Upregulation

    PubMed Central

    Kiessling, J. Willis; Bdeir, Khalil; Kofke, W. Andrew; Vavilala, Monica S.

    2010-01-01

    Abstract Cerebrospinal fluid (CSF) adrenomedullin (ADM) levels are increased in female, but remain unchanged in male, piglets after fluid percussion injury (FPI) of the brain. Subthreshold vascular concentrations of ADM restore impaired hypotensive pial artery dilation after FPI more in males than females. Extracellular signal-related kinase (ERK) mitogen-activated protein kinase (MAPK) is upregulated and contributes to reductions in cerebral blood flow (CBF) after FPI. We hypothesized that ADM prevents sex-dependent impairment of autoregulation during hypotension after FPI through inhibition of ERK MAPK upregulation. FPI increased ERK MAPK more in males than in females. CBF was unchanged during hypotension in sham animals, was reduced more in males than in females after FPI during normotension, and was further reduced in males than in females during hypotension and after FPI. ADM and the ERK MAPK antagonist U 0126 prevented reductions in CBF during hypotension and FPI more in males than in females. Transcranial Doppler (TCD) blood flow velocity was unchanged during hypotension in sham animals, was decreased during hypotension and FPI in male but not in female pigs, and was ameliorated by ADM. Intracranial pressure (ICP) was increased after FPI more in male than in female animals. ADM blunted elevated ICP during FPI and hypotension in males, but not in females. ADM prevented reductions in cerebral perfusion pressure (CPP) during FPI and hypotension in males but not in females. The calculated autoregulatory index was unchanged during hypotension in sham animals, but was reduced more in males than females during hypotension and FPI. ADM prevented reductions in autoregulation during hypotension and FPI more in males than females. These data indicate that ADM prevented loss of cerebral autoregulation after FPI in a sex-dependent and ERK MAPK-dependent manner. PMID:20170313

  15. Swash mark and grain flow

    USGS Publications Warehouse

    Sallenger,, Asbury H.

    1981-01-01

    Swash marks composed entirely of coarse sand are commonly found on coarse-sand beaches. These swash marks are 10 to 30 centimeters in width and a few millimeters to one centimeter in height. Previous observations, mostly on finer-sand beaches, indicate swash marks are seldom over a few millimeters in height and are commonly composed of material readily floated by surface tension (e.g., mica flakes and shell fragments). Swash marks composed of coarse sand have both fining seaward and fining with depth trends in grain size. Apparently, the leading margin of a wave upwash drives a highly concentrated flow of grains in which both grain size and grain velocity decrease with depth. Therefore, large grains are transported at greater velocities than are smaller grains. Thus, at the maximum advance of an upwash, a swash mark is deposited which has the observed fining seaward and fining with depth trends in grain size.

  16. Preoperative characteristics predicting intraoperative hypotension and hypertension among hypertensives and diabetics undergoing noncardiac surgery.

    PubMed Central

    Charlson, M E; MacKenzie, C R; Gold, J P; Ales, K L; Topkins, M; Shires, G T

    1990-01-01

    We prospectively studied patients with hypertension and diabetes undergoing elective noncardiac surgery with general anesthesia to test the hypothesis that patients at high risk for prognostically significant intraoperative hemodynamic instability could be identified by their preoperative characteristics. Specifically we hypothesized that patients with a low functional capacity, decreased plasma volume, or significant cardiac comorbidity would be at high risk for intraoperative hypotension and those with a history of severe hypertension would be at risk for intraoperative hypertension. Patients who had a preoperative mean arterial pressure (MAP) greater than or equal to 110, a walking distance of less than 400 m, or a plasma volume less than 3000 cc were at increased risk of intraoperative hypotension (i.e., more than 1 hour of greater than or equal to 20 mmHg decreases in the MAP). Hypotension was also more common among patients having intra-abdominal or vascular surgery, and among those who had operations longer than 2 hours. Patients older than 70 years or with a decreased plasma volume were at increased risk of having more than 15 minutes of intraoperative elevations of greater than or equal to 20 mmHg over the preoperative MAP in combination with intraoperative hypotension; this was also more common when surgery lasted more than 2 hours. Patients who had intraoperative hypotension tended to have an immediate decrease in MAP at the onset of anesthesia and were often purposefully maintained at MAPs less than their usual level during surgery with fentanyl and neuromuscular blocking agents. Patients who had intraoperative hyper/hypotension tended to have repeated elevations in MAP above their preoperative levels during the course of surgery, and such elevations precipitated interventions with neuromuscular blocking agents and/or fentanyl. Neither pattern was more common among patients who developed net intraoperative negative fluid balances. Both hypotension and

  17. Prehospital Nitroglycerin in Tachycardic Chest Pain Patients: A Risk for Hypotension or Not?

    PubMed

    Proulx, Marie-Hélène; de Montigny, Luc; Ross, Dave; Vacon, Charlene; Juste, Louis Enock; Segal, Eli

    2017-01-01

    The American Heart Association guidelines (AHA) guidelines list tachycardia as a contraindication for the administration of nitroglycerin (NTG), despite limited evidence of adverse events. We sought to determine whether NTG administered for chest pain was a predictor of hypotension (systolic blood pressure <90 mmHg) in patients with tachycardia, compared to patients without tachycardia (50≥ heart rate ≤100). We performed a retrospective cohort study using patient care reports completed by basic life support (BLS) providers in a large urban Canadian EMS system for the period 2010-2012. We used logistic regression to test the association between post-NTG hypotension and tachycardia, independent of pre-NTG blood pressure, age, sex, and comorbidities. Using identical models, we tested four secondary outcomes (drop in blood pressure, reduced consciousness, bradycardia, and cardiac arrest). The cohort included 10,308 patients who were administered NTG by BLS in the prehospital setting; 2,057 (20%) of patients were tachycardic before NTG administration. Hypotension occurred in 320 of all patients (3.1%): 239 without tachycardia (2.9%) and 81 with tachycardia (3.9%). Compared to non-tachycardic patients, tachycardic patients showed increased adjusted odds of hypotension (AOR: 1.60; 95% CI: 1.23-2.08) or of a drop in blood pressure of 30mm Hg or greater (AOR: 1.11; CI: 1.00-1.24). Tachycardia was associated with decreased odds of bradycardia (OR: 0.33; CI: 0.17-0.64). We did not find a significant association between tachycardia and either post-NTG reduced level of consciousness or cardiac arrest. We did find a strong, significant association between pre-NTG blood pressure and post-NTG hypotension (AOR for units of 10mmHg: 0.64; CI: 0.61-0.69). Hypotension following prehospital administration of NTG was infrequent in patients with chest pain. However, while the absolute risk of NTG-induced hypotension was low, patients with pre-NTG tachycardia had a significant increase

  18. Forced diuresis and dual-phase 18F-fluorodeoxyglucose-PET/CT scan for restaging of urinary bladder cancers

    PubMed Central

    Harkirat, S; Anand, SS; Jacob, MJ

    2010-01-01

    Context: The results of 18F-fluorodeoxyglucose (FDG)-PET imaging carried out with the current standard techniques for assessment of urinary tract cancers have been reported to be less than satisfactory because of the urinary excretion of the tracer. Aims: To investigate the role of dual-phase FDG-PET/CT in the restaging of invasive cancers of the urinary bladder, with delayed imaging after forced diuresis and oral hydration as the scanning protocol. Settings and Design: FDG-PET has been considered to be of limited value for the detection of urinary tract cancers because of interference by the FDG excreted in urine. We investigated the efficacy of delayed FDG-PET/CT in the restaging of invasive bladder cancer, with imaging performed after intravenous (IV) administration of a potent diuretic and oral hydration. Materials and Methods: Twenty-nine patients with invasive cancer of the urinary bladder were included in this study. Patients were divided into two groups: Group I (22 patients) included cases with invasive bladder cancer who had not undergone cystectomy and group II (seven patients) included cases with invasive bladder cancer who had undergone cystectomy and urinary diversion procedure. All patients underwent FDG-PET/CT scan from the skull base to the mid-thighs 60 min after IV injection of 370 mega-Becquerel (MBq) of FDG. Additional delayed images were acquired 60-90 min after IV furosemide and oral hydration. PET/CT data were analyzed as PET and CT images studied separately as well as fused PET/CT images and the findings were recorded. The imaging findings were confirmed by cystoscopy, biopsy or follow-up PET/CT. Results: The technique was successful in achieving adequate washout of urinary FDG and overcame the problems posed by the excess FDG in the urinary tract. Hypermetabolic lesions could be easily detected by PET and precisely localized to the bladder wall, perivesical region and pelvic lymph nodes. PET/CT delayed images were able to demonstrate 16

  19. A quantitative study of intracranial hypotensive syndrome by magnetic resonance.

    PubMed

    Tian, Weizhong; Zhang, Ji; Chen, Jinhua; Liu, Ying; Chen, Xiaoyun; Wang, Ning

    2016-02-01

    The study aims to investigate the magnetic resonance imaging (MRI) findings of intracranial hypotension syndrome (IHS) and the change of quantitative indicators, so as to yield a deeper understanding of the disease. The clinical data and MRI findings of 26 cases of IHS which were confirmed by lumbar puncture were retrospectively analyzed. Two physicians evaluated the MRI findings including thickening and enhancement of dural, pituitary enlargement, subdural effusion (hematocele), venous engorgement and brain sagging, and measured the quantitative indicators including mamillopontine distance and pontomesencephalic angle. The consistency between the two results of the physicians was assessed by Kappa consistency test. The differences of mamillopontine distance and pontomesencephalic angle between the patient group and the control group were determined by paired t-test. The diagnostic efficiency of mamillopontine distance and pontomesencephalic angle was assessed by area under the ROC curve, and their best diagnostic thresholds were also determined, respectively. Age- and sex-matched healthy volunteers controls (n=26) were recruited and served as the control group. All of the 26 patients suffered from the characterized by orthostatic headache of IHS. The clinical evaluations of dural thickening and enhancement, pituitary enlargement, subdural effusion (hematocele), venous engorgement by the two physicians showed excellent agreements (κ=0.808, 1 and 0.906, P<0.01), and the clinical evaluations of brain sagging showed medium agreements (κ=0.606, P<0.01). The mamillopontine distance and pontomesencephalic angle of the patient group were 5.4 ± 1.6mm and 47.8 ± 8.7°, respectively, which were obviously less than those of the control group (6.9 ± 1.1mm and 61.0 ± 6.1°, respectively), and the differences were statistically significant (t=-4.563, P<0.01; t=-.329, P<0.01). The area under ROC curve of mamillopontine distance and pontomesencephalic angle were 0.774 and 0

  20. Factors associated with orthostatic hypotension in hospitalized elderly patients.

    PubMed

    Guérin, Aline; Bureau, Marie-Laure; Ghazali, Nisrin; Gervais, Raphaëlle; Liuu, Evelyne; Seité, Florent; Bellarbre, Fabienne; Ingrand, Pierre; Paccalin, Marc

    2016-06-01

    To assess the factors associated with orthostatic hypotension (OH) in hospitalized elderly patients. Prospective observational single center study. A French academic center. One hundred and thirty-one patients without OH symptoms who underwent OH testing. The OH test was performed when the patient was able to get out of the bed and was no longer receiving parenteral fluids. The blood pressure was measured after a 10-min rest while the patients were sitting and then standing at 1 and 3 min. Demographic data, co-morbidities, current medications and biological parameters were recorded. The mean patient age was 84.3 ± 7 years. The mean CIRS-G score was 10.6 ± 3.8. The OH test was performed 6.3 ± 3.9 days after admission and was positive in 39 (29.8 %) patients (95 % confidence interval (CI) 22, 38) and positive at 1 min in 87.2 % of the cases. Multivariate analysis showed that OH prevalence correlated with diabetes (odds ratio (OR) = 4.23; 95 % CI 1.10, 16.24; P = 0.03), serum 25-hydroxyvitamin D <20 ng/ml (OR = 3.38; 95 % CI 1.36, 8.42; P = 0.008), use of tranquilizers (anxiolytic and hypnotic) (OR = 2.96; 95 % CI 1.18, 7.4; P = 0.02), CIRS-G score (OR = 1.15; 95 % CI 1.01, 1.31; P = 0.03) and lack of diuretics (OR = 0.20; 95 % CI 0.06, 0.63; P = 0.005). In older adults, OH is often misdiagnosed because it is asymptomatic. As practitioners may be reluctant to perform the OH test because of time constraints, targeting a subgroup of patients with a higher risk of OH should be worthwhile to prevent further OH complications.

  1. Management of spontaneous intracranial hypotension - Transorbital ultrasound as discriminator.

    PubMed

    Fichtner, Jens; Ulrich, Christian T; Fung, Christian; Knüppel, Christin; Veitweber, Martina; Jilch, Astrid; Schucht, Philippe; Ertl, Michael; Schömig, Beate; Gralla, Jan; Z'Graggen, Werner J; Bernasconi, Corrado; Mattle, Heinrich P; Schlachetzki, Felix; Raabe, Andreas; Beck, Jürgen

    2016-06-01

    Spontaneous intracranial hypotension (SIH) is most commonly caused by cerebrospinal fluid (CSF) leakage. Therefore, we hypothesised that patients with orthostatic headache (OH) would show decreased optic nerve sheath diameter (ONSD) during changes from supine to upright position. Transorbital B-mode ultrasound was performed employing a high-frequency transducer for ONSD measurements in the supine and upright positions. Absolute values and changes of ONSD from supine to upright were assessed. Ultrasound was performed in 39 SIH patients, 18 with OH and 21 without OH, and in 39 age-matched control subjects. The control group comprised 20 patients admitted for back surgery without headache or any orthostatic symptoms, and 19 healthy controls. In supine position, mean ONSD (±SD) was similar in patients with (5.38±0.91 mm) or without OH (5.48±0.89 mm; p=0.921). However, in upright position, mean ONSD was different between patients with (4.84±0.99 mm) and without OH (5.53±0.99 mm; p=0.044). Furthermore, the change in ONSD from supine to upright position was significantly greater in SIH patients with OH (-0.53±0.34 mm) than in SIH patients without OH (0.05±0.41 mm; p≤0.001) or in control subjects (0.01±0.38 mm; p≤0.001; area under the curve: 0.874 in receiver operating characteristics analysis). Symptomatic patients with SIH showed a significant decrease of ONSD, as assessed by ultrasound, when changing from the supine to the upright position. Ultrasound assessment of the ONSD in two positions may be a novel, non-invasive tool for the diagnosis and follow-up of SIH and for elucidating the pathophysiology of SIH. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  2. Portacaval shunting attenuates portal hypertension and systemic hypotension in rat anaphylactic shock.

    PubMed

    Kamikado, Chiaki; Shibamoto, Toshishige; Zhang, Wei; Kuda, Yuhichi; Ohmukai, Chieko; Kurata, Yasutaka

    2011-03-01

    Anaphylactic shock in rats is characterized by antigen-induced hepatic venoconstriction and the resultant portal hypertension. We determined the role of portal hypertension in anaphylactic hypotension by using the side-to-side portacaval shunt- and sham-operated rats sensitized with ovalbumin (1 mg). We measured the mean arterial blood pressure (MAP), portal venous pressure (PVP), and central venous pressure (CVP) under pentobarbital anesthesia and spontaneous breathing. Anaphylactic hypotension was induced by an intravenous injection of ovalbumin (0.6 mg). In sham rats, the antigen caused not only an increase in PVP from 11.3 cmH(2)O to the peak of 27.9 cmH(2)O but also a decrease in MAP from 103 mmHg to the lowest value of 41 mmHg. CVP also decreased significantly after the antigen. In the portacaval shunt rats, in response to the antigen, PVP increased slightly, but significantly, to the peak of 17.5 cmH(2)O, CVP did not decrease, and MAP decreased to a lesser degree with the lowest value being 60 mmHg. These results suggest that the portacaval shunt attenuated anaphylactic portal hypertension and venous return decrease, partially preventing anaphylactic hypotension. In conclusion, portal hypertension is involved in rat anaphylactic hypotension presumably via splanchnic congestion resulting in decreased venous return and thus systemic arterial hypotension.

  3. Subclinical decelerations during developing hypotension in preterm fetal sheep after acute on chronic lipopolysaccharide exposure

    PubMed Central

    Lear, Christopher A.; Davidson, Joanne O.; Galinsky, Robert; Yuill, Caroline A.; Wassink, Guido; Booth, Lindsea C.; Drury, Paul P.; Bennet, Laura; Gunn, Alistair J.

    2015-01-01

    Subclinical (shallow) heart rate decelerations occur during neonatal sepsis, but there is limited information on their relationship with hypotension or whether they occur before birth. We examined whether subclinical decelerations, a fall in fetal heart rate (FHR) that remained above 100 bpm, were associated with hypotension in preterm fetal sheep exposed to lipopolysaccharide (LPS). Chronically-instrumented fetal sheep at 0.7 gestation received continuous low-dose LPS infusions (n = 15, 100 ng/kg over 24 h, followed by 250 ng/kg/24 h for 96 h) or saline (n = 8). Boluses of 1 μg LPS or saline were given at 48 and 72 h. FHR variability (FHRV) was calculated, and sample asymmetry was used to assess the severity and frequency of decelerations. Low-dose LPS infusion did not affect FHR. After the first LPS bolus, 7 fetuses remained normotensive, while 8 developed hypotension (a fall in mean arterial blood pressure of ≥5 mmHg). Developing hypotension was associated with subclinical decelerations, with a corresponding increase in sample asymmetry and FHRV (p < 0.05). The second LPS bolus was associated with similar but attenuated changes in FHR and blood pressure (p < 0.05). In conclusion, subclinical decelerations are not consistently seen during prenatal exposure to LPS, but may be a useful marker of developing inflammation-related hypotension before birth. PMID:26537688

  4. Hypotension induced by the concomitant use of a calcium-channel blocker and clarithromycin

    PubMed Central

    Takeuchi, Sayako; Tsujimoto, Toshihide

    2017-01-01

    In the elderly, calcium-channel blockers are the first-line treatment for hypertension, and macrolides are commonly prescribed antibiotics. Here we report a 78-year-old man taking nifedipine, diltiazem and carvedilol who presented with persistent hypotension and bradycardia after clarithromycin was prescribed. He was diagnosed with drug-induced hypotension and treated with fluid resuscitation and vasoactive agents. His symptoms gradually improved. He was transferred out of the intensive care unit 3 days after hospitalisation. Combining calcium-channel blockers and clarithromycin can cause vasodilatory hypotension. The concomitant use of calcium-channel blockers and macrolide antibiotics increases the levels of calcium-channel blockers in the blood as they are metabolised by cytochrome P450 3A4 (CYP3A4), which is inhibited by macrolide antibiotics. Moreover, the addition of another calcium-channel blocker and a β blocker can lower cardiac output due to bradycardia and worsen hypotension. Therefore, it is important to consider drug interactions when the cause of hypotension is unknown. PMID:28069789

  5. Should the 'C' in 'ABCDE' be altered to reflect the trend towards hypotensive resuscitation?

    PubMed

    Sapsford, W

    2008-01-01

    Fluid resuscitation of trauma victims currently differs, depending on whether the Advanced Trauma Life Support (ATLS), Prehospital Trauma Life Support (PHTLS) or Battlefield Advanced Trauma Life Support (BATLS) algorithm is utilised. Resuscitation protocol depends on the situation of the patient before definitive surgical control of the haemorrhage can be achieved, that is, in the prehospital phase (the urban, rural or battlefield setting) or in the emergency room. The principle difference is between hypotensive (PHTLS and BATLS, in the prehospital phase) and normotensive (ATLS, in the emergency room) resuscitation. The aim of this review was to determine if there is sufficient evidence to consider altering the ATLS resuscitation algorithm to a hypotensive model prior to definitive surgical control of haemorrhage. A literature review was conducted of the experimental and clinical evidence for hypotensive resuscitation. Uncontrolled haemorrhage models are too severe. They do not realistically mimic--and their results cannot easily be extrapolated into--clinical scenarios. One important clinical trial, inspired by these experimental models, has rightly influenced resuscitation of shocked prehospital patients towards a 'scoop and run' approach and permissive hypotension but it is specific to patients with penetrating trauma alone. There is insufficient evidence to alter the current ATLS algorithm in the emergency room in favour of hypotensive resuscitation. The future of resuscitation is considered.

  6. Evaluation of Leg Wrapping for the Prevention of Postspinal Hypotension in Cesarean Section under Spinal Anesthesia

    PubMed Central

    Bagle, Aparna Abhijit; Vishnu, Adithya; Kumar, Anil; Malik, Amit; Garg, Vinit; Khanvilkar, Gayatri

    2017-01-01

    Background: Spinal blockade provides excellent anesthesia for patients undergoing cesarean section. However, hypotension after spinal anesthesia is a common adverse effect that is commonly experienced in patients undergoing cesarean section. The aim of our study was to analyze if a simple technique like leg wrapping with elastic crepe bandage would be effective in controlling postspinal hypotension. Materials and Methods: Sixty full-term pregnant patients who were posted for cesarean section belonging to American Society of Anesthesiologists I and II were divided into two groups. Patients in Group W had their legs wrapped with elastic crepe bandage and in the other Group N, leg wrapping was not done. All the patients were preloaded with Ringer lactate at 10 ml/kg before the spinal anesthesia. The hemodynamic parameters were monitored every 3 min until the delivery of the baby and every 5 min until the end of surgery. If hypotension occurred, then along with crystalloid loading a bolus dose of mephentermine 6 mg was given intravenously. Statistical Analysis: Statistical software “Numbers version 3.6.1 (2566)” was used for statistical calculations. Results: Frequency of hypotension in Group W (10%) was significantly less compared to Group N (60%). Vasopressor requirement was significantly less in Group W (P = 0.009), which was highly significant. Conclusion: Wrapping of lower extremities was a simple, easy, and an effective method of decreasing episodes of hypotension and vasopressor requirement after spinal anesthesia in cesarean patients and needs to be practiced routinely. PMID:28663637

  7. Opportunities for Web-based Drug Repositioning: Searching for Potential Antihypertensive Agents with Hypotension Adverse Events.

    PubMed

    Wang, Kejian; Wan, Mei; Wang, Rui-Sheng; Weng, Zuquan

    2016-04-01

    Drug repositioning refers to the process of developing new indications for existing drugs. As a phenotypic indicator of drug response in humans, clinical side effects may provide straightforward signals and unique opportunities for drug repositioning. We aimed to identify drugs frequently associated with hypotension adverse reactions (ie, the opposite condition of hypertension), which could be potential candidates as antihypertensive agents. We systematically searched the electronic records of the US Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) through the openFDA platform to assess the association between hypotension incidence and antihypertensive therapeutic effect regarding a list of 683 drugs. Statistical analysis of FAERS data demonstrated that those drugs frequently co-occurring with hypotension events were more likely to have antihypertensive activity. Ranked by the statistical significance of frequent hypotension reporting, the well-known antihypertensive drugs were effectively distinguished from others (with an area under the receiver operating characteristic curve > 0.80 and a normalized discounted cumulative gain of 0.77). In addition, we found a series of antihypertensive agents (particularly drugs originally developed for treating nervous system diseases) among the drugs with top significant reporting, suggesting the good potential of Web-based and data-driven drug repositioning. We found several candidate agents among the hypotension-related drugs on our list that may be redirected for lowering blood pressure. More important, we showed that a pharmacovigilance system could alternatively be used to identify antihypertensive agents and sustainably create opportunities for drug repositioning.

  8. Renin-angiotensin system stimulates respiration during acute hypotension but not during hypercapnia.

    PubMed

    Ohtake, P J; Walker, J K; Jennings, D B

    1993-03-01

    We reported that intravenous infusion of angiotensin II (ANG II) stimulated ventilation (VE) in conscious dogs. Other studies in our laboratory have demonstrated that increases in respiration occurred in association with activation of the renin-angiotensin system during acute hypotension and during hypercapnia. Therefore, in conscious dogs (n = 5), we examined the effects of ANG II receptor blockade with intravenous saralasin (0.5 micrograms.kg-1.min-1) on respiratory responses during progressive nitroprusside-induced hypotension and during the ventilatory response to increased inspired fraction of CO2 (VRC). During hypotension (mean arterial pressure decreased approximately 20%) combined with ANG II receptor blockade, VE, heart rate, and arginine vasopressin increases were attenuated compared within unblocked studies. With ANG II receptor blockade during hypotension, alveolar ventilation and arterial PCO2 (PaCO2) were unchanged, which contrasted with a doubling of alveolar ventilation and a decrease of 4.8 +/- 1 Torr in PaCO2 in unblocked studies. During hypercapnia, the slope of the VRC was not affected by ANG II receptor blockade, but with 6.5% inspired CO2 fraction, VE and PaCO2 were lower than in unblocked studies. These results indicated that ANG II contributed to the respiratory response to a modest hypotension but did not affect respiratory sensitivity to CO2.

  9. Delta- and kappa-opioid receptors in the caudal midline medulla mediate haemorrhage-evoked hypotension.

    PubMed

    Henderson, Luke A; Keay, Kevin A; Bandler, Richard

    2002-04-16

    In mammals blood loss can trigger, shock, an abrupt, life-threatening hypotension and bradycardia. In the halothane-anaesthetised rat this response is blocked by inactivation of a discrete, vasodepressor area in the caudal midline medulla (CMM). Haemorrhagic shock is blocked also by systemic or ventricular injections of the opioid antagonist, naloxone. This study investigated, in the halothane anaesthetised rat, the contribution of delta-, kappa- and mu-opioid receptors in the CMM vasodepressor region to haemorrhage-evoked shock (i.e. hypotension and bradycardia) and its recovery. It was found that microinjections into the CMM of the delta-opioid receptor antagonist, naltrindole delayed and attenuated the hypotension and bradycardia evoked by haemorrhage, but did not promote recompensation. In contrast, CMM microinjections of the kappa-opioid receptor antagonist, nor-binaltorphamine, although it did not alter haemorrhage-evoked hypotension and bradycardia, did lead to a rapid restoration of AP, but not HR. CMM microinjections of the mu-opioid receptor antagonist, CTAP had no effect on haemorrhage-evoked shock or recompensation. These data indicate that delta- and kappa- (but not mu-) opioid receptor-mediated events within the CMM contribute to the hypotension and bradycardia evoked by haemorrhage and the effectiveness of naloxone in reversing shock.

  10. Pharmacologic inhibition of the renal outer medullary potassium channel causes diuresis and natriuresis in the absence of kaliuresis.

    PubMed

    Garcia, Maria L; Priest, Birgit T; Alonso-Galicia, Magdalena; Zhou, Xiaoyan; Felix, John P; Brochu, Richard M; Bailey, Timothy; Thomas-Fowlkes, Brande; Liu, Jessica; Swensen, Andrew; Pai, Lee-Yuh; Xiao, Jianying; Hernandez, Melba; Hoagland, Kimberly; Owens, Karen; Tang, Haifeng; de Jesus, Reynalda K; Roy, Sophie; Kaczorowski, Gregory J; Pasternak, Alexander

    2014-01-01

    The renal outer medullary potassium (ROMK) channel, which is located at the apical membrane of epithelial cells lining the thick ascending loop of Henle and cortical collecting duct, plays an important role in kidney physiology by regulating salt reabsorption. Loss-of-function mutations in the human ROMK channel are associated with antenatal type II Bartter's syndrome, an autosomal recessive life-threatening salt-wasting disorder with mild hypokalemia. Similar observations have been reported from studies with ROMK knockout mice and rats. It is noteworthy that heterozygous carriers of Kir1.1 mutations associated with antenatal Bartter's syndrome have reduced blood pressure and a decreased risk of developing hypertension by age 60. Although selective ROMK inhibitors would be expected to represent a new class of diuretics, this hypothesis has not been pharmacologically tested. Compound A [5-(2-(4-(2-(4-(1H-tetrazol-1-yl)phenyl)acetyl)piperazin-1-yl)ethyl)isobenzofuran-1(3H)-one)], a potent ROMK inhibitor with appropriate selectivity and characteristics for in vivo testing, has been identified. Compound A accesses the channel through the cytoplasmic side and binds to residues lining the pore within the transmembrane region below the selectivity filter. In normotensive rats and dogs, short-term oral administration of compound A caused concentration-dependent diuresis and natriuresis that were comparable to hydrochlorothiazide. Unlike hydrochlorothiazide, however, compound A did not cause any significant urinary potassium losses or changes in plasma electrolyte levels. These data indicate that pharmacologic inhibition of ROMK has the potential for affording diuretic/natriuretic efficacy similar to that of clinically used diuretics but without the dose-limiting hypokalemia associated with the use of loop and thiazide-like diuretics.

  11. [Relationship between regulation effect of salvia miltiorrhiza on AQP2 in kidney and promoting blood circulation and diuresis].

    PubMed

    Dong, Xiao-Jing; Guo, Liang-Feng; Yao, Rui; Xue, Song-Yan; Li, Feng

    2014-08-01

    Partial nature of "promoting blood circulation and dieresis" of Salvia Miltiorrhizain was initially demonstrated by investigating the regulation effect of AQP2 expression in kidney of trauma blood stasis model rats with the Salvia Miltiorrhizain so as to provide guidance for its clinical deployment of administration. Random allocation was taken to averagely divide 30 SD rats into two groups: 10 rats in normal group and 20 rats in blood stasis syndrome group. Trauma blood stasis rat model was established by quantitatively beating. Then the rat model group was divided into model group and salvia group. After 7 days of treatment, the rat kidney AQP2 expression was detected, the content of urine AQP2 was compared and the damaged local muscle and kidney pathological changes were observed by immunohistochemical method and western blot method. Compared with that of the normal group, rats in model group had inflammatory cells infiltration, blood stasis and edema of the injured local muscles and up-regulated AQP2 expression, decreasing urinary output, and kidney tissues blood stasis and edema (P < 0.05). On the other hand, compared with that of the model group, those parameters of rats in salvia group were all decreasing except urine output (P < 0.05). Such result indicated that Salvia Miltiorrhiza can reduce trauma blood stasis rat content of urine AQP2 and down-regulated AQP2 expression in kidney tissue, so as to reduce the reabsorption of water by renal tubular and increase urine output. The promoting blood circulation effect of Salvia Miltiorrhizain can alleviate the degree of the damaged tissue edema and encourage urine drainage. This therapy is closely related to the effect of regulating AQP2 in kidney by salvia, so the purpose of this study by verifying "promoting blood circulation and diuresis" as the mechanism for the regulation effect of the salvia on AQP2 expression.

  12. Vhl deletion in renal epithelia causes HIF-1α-dependent, HIF-2α-independent angiogenesis and constitutive diuresis

    PubMed Central

    Schönenberger, Désirée; Rajski, Michal; Harlander, Sabine; Frew, Ian J.

    2016-01-01

    One of the earliest requirements for the formation of a solid tumor is the establishment of an adequate blood supply. Clear cell renal cell carcinomas (ccRCC) are highly vascularized tumors in which the earliest genetic event is most commonly the biallelic inactivation of the VHL tumor suppressor gene, leading to constitutive activation of the HIF-1α and HIF-2α transcription factors, which are known angiogenic factors. However it remains unclear whether either or both HIF-1α or HIF-2α stabilization in normal renal epithelial cells are necessary or sufficient for alterations in blood vessel formation. We show that renal epithelium-specific deletion of Vhl in mice causes increased medullary vascularization and that this phenotype is completely rescued by Hif1a co-deletion, but not by co-deletion of Hif2a. A physiological consequence of changes in the blood vessels of the vasa recta in Vhl-deficient mice is a diabetes insipidus phenotype of excretion of large amounts of highly diluted urine. This constitutive diuresis is fully compensated by increased water consumption and mice do not show any signs of dehydration, renal failure or salt wasting and blood electrolyte levels remain unchanged. Co-deletion of Hif1a, but not Hif2a, with Vhl, fully restored kidney morphology and function, correlating with the rescue of the vasculature. We hypothesize that the increased medullary vasculature alters salt uptake from the renal interstitium, resulting in a disruption of the osmotic gradient and impaired urinary concentration. Taken together, our study characterizes a new mouse model for a form of diabetes insipidus and non-obstructive hydronephrosis and provides new insights into the physiological and pathophysiological effects of HIF-1α stabilization on the vasculature in the kidney. PMID:27528422

  13. Vhl deletion in renal epithelia causes HIF-1α-dependent, HIF-2α-independent angiogenesis and constitutive diuresis.

    PubMed

    Schönenberger, Désirée; Rajski, Michal; Harlander, Sabine; Frew, Ian J

    2016-09-20

    One of the earliest requirements for the formation of a solid tumor is the establishment of an adequate blood supply. Clear cell renal cell carcinomas (ccRCC) are highly vascularized tumors in which the earliest genetic event is most commonly the biallelic inactivation of the VHL tumor suppressor gene, leading to constitutive activation of the HIF-1α and HIF-2α transcription factors, which are known angiogenic factors. However it remains unclear whether either or both HIF-1α or HIF-2α stabilization in normal renal epithelial cells are necessary or sufficient for alterations in blood vessel formation. We show that renal epithelium-specific deletion of Vhl in mice causes increased medullary vascularization and that this phenotype is completely rescued by Hif1a co-deletion, but not by co-deletion of Hif2a. A physiological consequence of changes in the blood vessels of the vasa recta in Vhl-deficient mice is a diabetes insipidus phenotype of excretion of large amounts of highly diluted urine. This constitutive diuresis is fully compensated by increased water consumption and mice do not show any signs of dehydration, renal failure or salt wasting and blood electrolyte levels remain unchanged. Co-deletion of Hif1a, but not Hif2a, with Vhl, fully restored kidney morphology and function, correlating with the rescue of the vasculature. We hypothesize that the increased medullary vasculature alters salt uptake from the renal interstitium, resulting in a disruption of the osmotic gradient and impaired urinary concentration. Taken together, our study characterizes a new mouse model for a form of diabetes insipidus and non-obstructive hydronephrosis and provides new insights into the physiological and pathophysiological effects of HIF-1α stabilization on the vasculature in the kidney.

  14. Mark-specific hazard ratio model with missing multivariate marks.

    PubMed

    Juraska, Michal; Gilbert, Peter B

    2016-10-01

    An objective of randomized placebo-controlled preventive HIV vaccine efficacy (VE) trials is to assess the relationship between vaccine effects to prevent HIV acquisition and continuous genetic distances of the exposing HIVs to multiple HIV strains represented in the vaccine. The set of genetic distances, only observed in failures, is collectively termed the 'mark.' The objective has motivated a recent study of a multivariate mark-specific hazard ratio model in the competing risks failure time analysis framework. Marks of interest, however, are commonly subject to substantial missingness, largely due to rapid post-acquisition viral evolution. In this article, we investigate the mark-specific hazard ratio model with missing multivariate marks and develop two inferential procedures based on (i) inverse probability weighting (IPW) of the complete cases, and (ii) augmentation of the IPW estimating functions by leveraging auxiliary data predictive of the mark. Asymptotic properties and finite-sample performance of the inferential procedures are presented. This research also provides general inferential methods for semiparametric density ratio/biased sampling models with missing data. We apply the developed procedures to data from the HVTN 502 'Step' HIV VE trial.

  15. CE Marking - the Essential Requirements

    NASA Astrophysics Data System (ADS)

    Playle, Mervyn

    The European Union (EU) harmonisation project introduced the CE marking of products to enable the free, unhindered movement of goods throughout the European market. The CE mark replaced the EC mark in the mid 1990s and is fundamental to the New Approach Directives. When a product falls within the scope of a New Approach Directive the manufacturer must comply with the 'goal setting' essential requirements of the directive, to follow one of the conformity assessment procedures provided for, and to draw up the technical documentation specified. Although not mandatory, a manufacturer can choose to satisfy the essential requirements through the application of European harmonised standards.

  16. Oral midodrine is effective for the treatment of hypotension associated with carotid artery stenting.

    PubMed

    Sharma, Sanjiv; Lardizabal, Joel A; Bhambi, Brijesh

    2008-06-01

    Hypotension is commonly encountered during carotid artery stenting (CAS), mediated by vagal stimulation and suppression of sympathetic outflow. Some patients require treatment with intravenous vasopressors (dopamine, nor-epinephrine, or phenylephrine). The authors describe the successful use of the oral agent midodrine as an alternative to intravenous vasopressors in the treatment of hypotension related to CAS. Of 55 patients who underwent elective CAS, 19 (35%) experienced significant hypotension, and 15 (27%) required vasopressor therapy. Eleven patients received intravenous dopamine infusion in an intensive care setting, whereas 4 received oral midodrine in a regular telemetry unit. All patients eventually recovered and were discharged without any residual cardiovascular or neurological complications. No major side effects were noted with the use of both dopamine and midodrine. Cost of hospitalization was significantly higher in the dopamine group because of the need for ICU admission.

  17. Risk Prediction for Acute Hypotensive Patients by Using Gap Constrained Sequential Contrast Patterns

    PubMed Central

    Ghosh, Shameek; Feng, Mengling; Nguyen, Hung; Li, Jinyan

    2014-01-01

    The development of acute hypotension in a critical care patient causes decreased tissue perfusion, which can lead to multiple organ failures. Existing systems that employ population level prognostic scores to stratify the risks of critical care patients based on hypotensive episodes are suboptimal in predicting impending critical conditions, or in directing an effective goal-oriented therapy. In this work, we propose a sequential pattern mining approach which target novel and informative sequential contrast patterns for the detection of hypotension episodes. Our results demonstrate the competitiveness of the approach, in terms of both prediction performance as well as knowledge interpretability. Hence, sequential patterns-based computational biomarkers can help comprehend unusual episodes in critical care patients ahead of time for early warning systems. Sequential patterns can thus aid in the development of a powerful critical care knowledge discovery framework for facilitating novel patient treatment plans. PMID:25954447

  18. A rare presentation of an ancient disease: scurvy presenting as orthostatic hypotension

    PubMed Central

    Zipursky, Jonathan Samuel; Alhashemi, Ahmad; Juurlink, David

    2014-01-01

    A 49-year-old man presented to hospital with severe orthostatic hypotension, gingival dysplasia and a purpuric rash involving his extremities. The orthostatic hypotension failed to respond to fluids and, on the basis of physical examination and dietary history, the patient was given a preliminary diagnosis of scurvy (ascorbic acid deficiency). Serum ascorbic acid levels were undetectable and the orthostasis was resolved within 24 h of ascorbic acid replacement. The pathogenesis of orthostatic hypotension in the setting of scurvy appears to involve impaired catecholamine synthesis and attenuated vasomotor response to α-adrenergic stimulation. We believe that this case describes a rare presentation of scurvy and highlights a previously under-reported connection between scurvy and vasomotor instability. PMID:24859547

  19. A rare presentation of an ancient disease: scurvy presenting as orthostatic hypotension.

    PubMed

    Zipursky, Jonathan Samuel; Alhashemi, Ahmad; Juurlink, David

    2014-05-23

    A 49-year-old man presented to hospital with severe orthostatic hypotension, gingival dysplasia and a purpuric rash involving his extremities. The orthostatic hypotension failed to respond to fluids and, on the basis of physical examination and dietary history, the patient was given a preliminary diagnosis of scurvy (ascorbic acid deficiency). Serum ascorbic acid levels were undetectable and the orthostasis was resolved within 24 h of ascorbic acid replacement. The pathogenesis of orthostatic hypotension in the setting of scurvy appears to involve impaired catecholamine synthesis and attenuated vasomotor response to α-adrenergic stimulation. We believe that this case describes a rare presentation of scurvy and highlights a previously under-reported connection between scurvy and vasomotor instability. 2014 BMJ Publishing Group Ltd.

  20. Refractory Hypotension after Liver Allograft Reperfusion: A Case of Dynamic Left Ventricular Outflow Tract Obstruction

    PubMed Central

    Essandoh, Michael; Otey, Andrew Joseph; Dalia, Adam; Dewhirst, Elisabeth; Springer, Andrew; Henry, Mitchell

    2016-01-01

    Hypotension after reperfusion is a common occurrence during liver transplantation following the systemic release of cold, hyperkalemic, and acidic contents of the liver allograft. Moreover, the release of vasoactive metabolites such as inflammatory cytokines and free radicals from the liver and mesentery, compounded by the hepatic uptake of blood, may also cause a decrement in systemic perfusion pressures. Thus, the postreperfusion syndrome (PRS) can materialize if hypotension and fibrinolysis occur concomitantly within 5 min of reperfusion. Treatment of the PRS may require the administration of inotropes, vasopressors, and intravenous fluids to maintain hemodynamic stability. However, the occurrence of the PRS and its treatment with inotropes and calcium chloride may lead to dynamic left ventricular outflow tract obstruction (DLVOTO) precipitating refractory hypotension. Expedient diagnosis of DLVOTO with transesophageal echocardiography is extremely vital in order to avoid potential cardiovascular collapse during this critical period. PMID:26909349

  1. Blood Pressure Drop Prediction by using HRV Measurements in Orthostatic Hypotension.

    PubMed

    Sannino, Giovanna; Melillo, Paolo; Stranges, Saverio; De Pietro, Giuseppe; Pecchia, Leandro

    2015-11-01

    Orthostatic Hypotension is defined as a reduction of systolic and diastolic blood pressure within 3 minutes of standing, and may cause dizziness and loss of balance. Orthostatic Hypotension has been considered an important risk factor for falls since 1960. This paper presents a model to predict the systolic blood pressure drop due to orthostatic hypotension, relying on heart rate variability measurements extracted from 5 minute ECGs recorded before standing. This model was developed and validated with the leave-one-out cross-validation technique involving 10 healthy subjects, and finally tested with an additional 5 healthy subjects, whose data were not used during the training and cross-validation process. The results show that the model predicts correctly the systolic blood pressure drop in 80 % of all experiments, with an error rate below the measurement error of a sphygmomanometer digital device.

  2. [Prophylaxis and treatment of arterial hypotension during caesarean with spinal anaesthesia].

    PubMed

    Arias, J; Lacassie, H J

    2013-11-01

    Caesarean section is one of the most common surgical procedures worldwide. Arterial hypotension is the most prevalent adverse effect after spinal anaesthesia. Various methods have been used to prevent or treat hypotension. Since there is no treatment 100% effective by itself, a multimodal management is required to achieve an optimum balance and avoidance of hemodynamic imbalance. Strategies to avoid this side effect are analyzed on the basis of the best evidence available so far, summarized as mechanical factors, anesthetics, fluids and vasopressors. After spinal anaesthesia for caesarean section, the best strategy available for prevention of hypotension appears to be the combination of crystalloids along with an alpha 1 agonist vasopressor. Copyright © 2012 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Published by Elsevier España. All rights reserved.

  3. Hypotensive effect of hydroxylamine, an endogenous nitric oxide donor and SSAO inhibitor.

    PubMed

    Vidrio, H; Medina, M

    2007-01-01

    The endogenous compound hydroxylamine relaxes vascular smooth muscle in vitro, apparently through conversion to the vasodilator factor nitric oxide, but its effect on blood pressure has not been characterized. We found that in the anesthetized rat the amine elicits dose-related hypotension when administered by continuous iv infusion. In experiments designed to explore the mechanism of this effect, hydroxylamine was compared with the nitric oxide donor nitroprusside and the direct-acting vasodilator hydralazine, using pretreatments known to modify diverse mechanisms of vasodilation. Hydroxylamine hypotension was enhanced by the SSAO inhibitor isoniazid and the SSAO substrate methylamine, a pattern shared by hydralazine. Responses were blocked by the guanylate cyclase inhibitor methylene blue and were increased by the nitric oxide synthase inhibitor L-NAME, a pattern shared by nitroprusside. It was concluded that hydroxylamine exerts hypotension partly through conversion to nitric oxide and partly by a "hydralazine-like" mechanism involving SSAO inhibition.

  4. A peptide released by pepsin from kininogen domain 1 is a potent blocker of ANP-mediated diuresis-natriuresis in the rat.

    PubMed

    Croxatto, H R; Silva, R; Figueroa, X; Albertini, R; Roblero, J; Boric, M P

    1997-10-01

    A 20-amino acid peptide, KYEIKEGDCPVQSGKTWQDC (PU-D1), released by pepsin hydrolysis of LMW kininogen domain 1 was tested for its ability to antagonize the diuretic and natriuretic effect of ANP(103-125) in anesthetized rats. A single dose of 10.8 or 21.6 pmol (25 or 50 ng) PU-D1 given intravenously or into the duodenal lumen suppressed the diuresis-natriuresis induced by 209 pmol (500 ng) ANP by 43% to 59% and 69% to 96%, respectively. None of the doses tested (2.16 to 432 pmol, 5 ng to 1 microg) modified systemic blood pressure. Strikingly, a single IV dose of 10.8 pmol PU-D1 blocked the action of ANP for more than 3 hours. ANP blockade by PU-D1 was annulled completely by the bradykinin (BK) B2 receptor inhibitor Hoe 140. On a molar basis, PU-D1 is more effective than BK and kinins of 15, 16, and 18 amino acids for blocking the ANP-mediated diuresis-natriuresis. As with BK and other kinins, the inhibitory effect of Pu-D1 on ANP is obtained only within a small range of picomol doses. A single dose of 2.16 or 4.32 pmol PU-D1 or 47 pmol (50 ng) BK is ineffective against ANP if injected alone. However, when both substances are administered concomitantly at these subthreshold doses, they totally suppress ANP-induced diuresis-natriuresis. These results raise the question of whether PU-D1, released from kininogen domain 1, either alone or associated with BK, may interact with ANP in the regulation of urinary water and electrolyte excretion in physiological and pathological conditions.

  5. Eukaliuric diuresis and natriuresis in response to the KATP channel blocker U37883A: micropuncture studies on the tubular site of action.

    PubMed

    Huang, D Y; Osswald, H; Vallon, V

    1999-08-01

    1. Systemic application of U37883A, a blocker of ATP sensitive potassium (KATP) channels, elicits diuresis and natriuresis without significantly altering urinary potassium excretion. 2. To elucidate tubular sites of action upstream to the distal nephron, micropuncture experiments were performed in nephrons with superficial glomeruli of anaesthetized Munich-Wistar-Frömter rats during systemic application of U37883A (1, 5 or 15 mg kg-1 i.v.). 3. The observed eukaliuric diuresis and natriuresis in response to U37883A at 15 mg kg-1 was accompanied by an increase in early distal tubular flow rate (VED) from 10 - 18 nl min(-1) reflecting a reduction in fractional reabsorption of fluid up to this site (FR-fluid) of 13%. The latter proposed an effect on water-permeable segments such as the proximal tubule which could fully account for the observed reduction in fractional reabsorption of Na+ up to the early distal tubule (FR-Na+) of 8% and the increase in early distal tubular Na+ concentration ([Na+]ED) from 35 - 51 mM whereas [K+]ED was left unaltered. 4. In comparison, furosemide (3 mg kg-1 i.v.), which acts in the water-impermeable thick ascending limb, elicited diuresis, natriuresis and kaliuresis which were associated with a fall in FR-Na+ of 10% with no change in FR-fluid, and a rise in [Na+]ED from 42 - 117 mM and [K+]ED from 1.2 - 5.7 mM with no change in VED. 5. Direct late proximal tubular fluid collections confirmed a significant inhibition of fluid reabsorption in proximal convoluted tubule in response to systemic application of U37883A. 6. These findings suggest that the diuretic and natriuretic effect upstream to the distal tubule in response to systemic application of U37883A involves actions on water-permeable segments such as the proximal convoluted tubule.

  6. Automatic adaptive system dialysis for hemodialysis-associated hypotension and intolerance: a noncontrolled multicenter trial.

    PubMed

    Colì, Luigi; La Manna, Gaetano; Comai, Giorgia; Ursino, Mauro; Ricci, Davide; Piccari, Matteo; Locatelli, Francesco; Di Filippo, Salvatore; Cristinelli, Luciano; Bacchi, Massimo; Balducci, Alessandro; Aucella, Filippo; Panichi, Vincenzo; Ferrandello, Francesco Paolo; Tarchini, Renzo; Lambertini, Domenica; Mura, Carlo; Marinangeli, Giancarlo; Di Loreto, Ermanno; Quarello, Francesco; Forneris, Giacomo; Tancredi, Maurizio; Morosetti, Massimo; Palombo, Giuditta; Di Luca, Marina; Martello, Mauro; Emiliani, Giuseppe; Bellazzi, Roberto; Stefoni, Sergio

    2011-07-01

    Hemodialysis is complicated by a high incidence of intradialytic hypotension and disequilibrium symptoms caused by hypovolemia and a decrease in extracellular osmolarity. Automatic adaptive system dialysis (AASD) is a proprietary dialysis system that provides automated elaboration of dialysate and ultrafiltration profiles based on the prescribed decrease in body weight and sodium content. A noncontrolled (single arm), multicenter, prospective, clinical trial. 55 patients with intradialytic hypotension or disequilibrium syndrome in 15 dialysis units were studied over a 1-month interval using standard treatment (642 sessions) followed by 6 months using AASD (2,376 sessions). AASD (bicarbonate dialysis with dialysate sodium concentration and ultrafiltration rate profiles determined by the automated procedure). Primary and major secondary outcomes were the frequency of intradialytic hypotension and symptoms (hypotensive events, headache, nausea, vomiting, and cramps), respectively. More stable intradialytic systolic and diastolic blood pressures with lower heart rate were found using AASD compared with standard treatment. Sessions complicated by hypotension decreased from 58.7% ± 7.3% to 0.9% ± 0.6% (P < 0.001). The incidence of other disequilibrium syndrome symptoms was lower in patients receiving AASD. There were no differences in end-session body weight, interdialytic weight gain, or presession natremia between the standard and AASD treatment periods. A noncontrolled (single arm) study, no crossover from AASD to standard treatment. This study shows the long-term clinical efficacy of AASD for intradialytic hypotension and disequilibrium symptoms in a large number of patients and dialysis sessions. Copyright © 2011 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

  7. Modulation of oxidative stress and microinflammatory status by colloids in refractory dialytic hypotension

    PubMed Central

    2011-01-01

    Background Intradialytic hypotension may adversely affect the outcome of chronic hemodialysis. Therapeutic albumin has powerful anti-oxidant and anti-inflammatory properties. We have recently shown that systematic colloid infusion during hemodialysis sessions improves hemodynamic parameters in most dialysis hypotension-prone patients unresponsive to usual of preventive measures. We postulated that frequent hypotensive episodes may lead to a noxious inflammatory response mediated by oxidative stress induced by ischemia-reperfusion. The aim of this study was therefore to analyze the effect of 20% albumin and 4% gelatin infusions on oxidative stress and microinflammatory status in hypotension-prone patients unresponsive to usual preventive measures. Methods Prospective cross-over study (lasting 20 weeks) of routine infusion of 200 ml of 20% albumin versus 200 ml of 4% gelatin in 10 patients with refractory intradialytic hypotension. We analyzed the effect of 20% albumin and 4% gelatin on microinflammatory status, oxidative stress, serum nitrite and nitrate levels by analysis of variance. Results A significant decrease in serum ceruloplasmin and serum C3 was observed during the albumin period (p < 0.05, repeated measure ANOVA). A significant decrease in serum hydrogen peroxide was seen during albumin and gelatin administration (p < 0.01, repeated measure ANOVA) and a very large decrease in serum lipid peroxides was observed during the albumin period only (p < 0.01, Friedman test). Serum lactoferrin, serum proinflammatory cytokines and serum nitrite and nitrate levels remained stable during the different periods of this pilot trial. Conclusions We conclude that the improvement in microinflammatory status observed during colloid infusion in hypotension-prone dialysis patients may be related to a decrease in ischemia-reperfusion of noble organs, together with a specific reduction in oxidative stress by albumin. Trial registration ISRCTN 20957055 PMID:22013952

  8. Vasopressor choice for hypotension in elective Cesarean section: ephedrine or phenylephrine?

    PubMed Central

    Gunda, Chandrakala P.; Malinowski, Jennifer; Tegginmath, Aruna; Suryanarayana, Venkatesh G.

    2010-01-01

    Introduction Hypotensive episodes are a common complication of spinal anesthesia during Cesarean section. The purpose of this study was to compare the effectiveness and the side effects of vasopressors, ephedrine and phenylephrine, administered for hypotension during elective Cesarean section under spinal anesthesia. Material and methods The study consisted of 100 selected ASA I/II females scheduled for elective Cesarean section under spinal anesthesia. Each patient was randomly assigned to one of the two double-blind study groups. Group E received 1 ml ephedrine (5 mg/ml) with normal saline if hypotension was present (n=50). Group P received 1 ml phenylephrine (100 µg/ml) with normal saline if hypotension developed (n=50). Heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP) were compared within and between groups to basal levels at time increments of 0, 2, 4, 6, 8, 10, 15, 20, 25, 30, 45, and 60 min from start of surgery. Incidence of side effects and neonatal outcomes were studied between groups. Results All patients required vasopressor therapy for hypotension. Administration of phenylephrine was associated with significant drop in HR. Changes in SBP, DBP, and MAP were similar in both groups for most observed times. The incidences of nausea/vomiting and tachycardia were significantly higher in the ephedrine group. Conclusions Phenylephrine and ephedrine are acceptable choices to combat maternal hypotension related to spinal anesthesia in elective Cesarean section. Complications of intra-operative nausea and vomiting, tachycardia and bradycardia should be considered when choosing a vasopressor, suggesting phenylephrine may be more appropriate when considering maternal well-being. PMID:22371756

  9. [Hydrocortisone for the treatment of refractory hypotension: a randomized controlled trial].

    PubMed

    Salas, G; Travaglianti, M; Leone, A; Couceiro, C; Rodríguez, S; Fariña, D

    2014-06-01

    Systemic hypotension is a common sign in critically sick infants. Several studies have suggested that the use of short series of corticosteroids increases arterial blood pressure and reduces the inotropic support needs in preterm neonates with hypotension. There are a small number of reports on the use of hydrocortisone (HC) for the treatment of refractory hypotension in infants. To assess the effectiveness of hydrocortisone in the reduction of inotropic support in infants with refractory hypotension. infants who required dopamine ≥ 14 μg/kg/min and/or epinephrine. prospective, controlled, randomized, double blind trial with placebo. 2.5mg/kg every 12 hours, for 48 hours intravenously (intervention group [IG]); placebo: isotonic saline 1.25 ml/kg/doses intravenously (placebo group [PG]) every 12 hours, for 48 hours. Randomization was performed in blocks with blind assignment. A total of 50 infants with refractory systemic hypotension were prospectively recruited. Patient characteristics were similar in both groups. Requirements for inotropic support at 48 hrs were achieved in 60%, of the IG versus 24% of the PG (P=.009, RR: 2.5, 95% CI, 1.16-5.38). A significant association was observed between the administration of HC in infants treated with epinephrine and the presence of hyperglycemia (P =.008). In patients with refractory hypotension hydrocortisone administration reduced the need for inotropic support. Further studies with a greater number of patients are needed to confirm the effectiveness of HC as a therapeutic tool in these infants. Copyright © 2013 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

  10. Reversible cerebral vasoconstriction syndrome and posterior reversible encephalopathy syndrome associated with intracranial hypotension.

    PubMed

    Feil, Katharina; Forbrig, Robert; Thaler, Franziska S; Conrad, Julian; Heck, Suzette; Dorn, Franziska; Pfister, Hans-Walter; Straube, Andreas

    2017-02-01

    Reversible cerebral vasoconstriction syndrome (RCVS) and posterior reversible encephalopathy syndrome (PRES) are both rare disorders. The pathophysiology of both diseases is not yet fully understood. We report the unique case of a 19-year-old comatose woman who was brought to the ER after a series of generalized tonic-clonic seizures 6 days post peridural anesthesia for cesarean section. Vital signs and initial laboratory testing including urine analysis and drug screening were unremarkable. Initial cranial CT scan showed an acute small subdural hematoma (17 mm length × 6 mm width × 30 mm height), cerebral edema with slit ventricles, and slight cerebellar tonsillar herniation as signs of intracranial hypotension. CT angiography depicted narrowing of the proximal intracranial vessels consistent with RCVS. MR imaging was also suggestive of both intracranial hypotension and RCVS and showed, in addition, vasogenic edema consistent with PRES. An extensive CSF leakage involving T1 to L2/L3 was confirmed by spinal MRI. The patient underwent conservative therapy for intracranial hypotension (e.g., head-down position) as well as epidural blood patch, which led to regression of the clinical symptoms within a few days. Follow-up MRI showed complete resolution of all radiological changes. In summary, our patient developed clinical and neuroradiological signs of intracranial hypotension and a combination of PRES and RCVS associated with a CSF leakage caused by peridural anesthesia; by treating the intracranial hypotension, the other syndromes resolved. From a clinical point of view, it is important to look for CSF leakage as a treatable possible cause of PRES and/or RCVS triggered by intracranial hypotension as in our patient postpartum. Moreover, it is vital to obtain a good history as, in cases of suspected CSF leakage with classic postural headache, a recent spinal/cranial procedure is typically present.

  11. Coronary effects of endothelin-1 and vasopressin during acute hypotension in anesthetized goats.

    PubMed

    Fernández, Nuria; Martínez, Ma Angeles; García-Villalón, Angel Luis; Monge, Luis; Diéguez, Godofredo

    2005-06-10

    Coronary effects of endothelin-1 and vasopressin during acute hypotension, and the role of NO and prostanoids in these effects were examined in anesthetized goats. Left circumflex coronary artery flow was measured electromagnetically, and hypotension was induced by constriction of the caudal vena cava in animals non-treated (7 goats) or treated with the inhibitor of NO synthesis N(w)-nitro-L-arginine methyl esther (L-NAME, 5 goats), the cyclooxygenase inhibitor meclofenamate (5 goats) or both drugs (5 goats). Under normotension (22 goats), mean arterial pressure averaged 93 +/- 3 mm Hg and coronary vascular conductance (CVC) 0.37 +/- 0.025 ml/min/mm Hg. Endothelin-1 (0.01-0.3 nmol) and vasopressin (0.03-1 nmol), intracoronarily injected, dose-dependently decreased CVC by up to 56% for endothelin-1 and 40% for vasopressin. During hypotension in every condition tested, mean arterial pressure decreased to approximately 60 mm Hg, and CVC only decreased during hypotension pretreated with L-NAME (23%) or L-NAME + meclofenamate (34%). Under non-treated hypotension, the decreases in CVC by endothelin-1 were augmented approximately 1.5 fold, and those by vasopressin were not modified. This increase in CVR by endothelin-1 was not affected by L-NAME and was reversed by meclofenamate or L-NAME + meclofenamate. The coronary effects of vasopressin were not modified by any of these treatments. Therefore, acute hypotension increases the coronary vasoconstriction in response to endothelin-1 but not to vasopressin. This increased response to endothelin-1 may be related to both inhibition of NO release and release of vasoconstrictor prostanoids.

  12. Patients' choice of portable folding chairs to reduce symptoms of orthostatic hypotension

    NASA Technical Reports Server (NTRS)

    Smit, A. A.; Wieling, W.; Opfer-Gehrking, T. L.; van Emmerik-Levelt, H. M.; Low, P. A.

    1999-01-01

    Patients with neurogenic orthostatic hypotension may use portable folding chairs to prevent or reduce symptoms of low blood pressure. However, a concomitant movement disorder may limit the use of these chairs in daily living. In this prospective study, 13 patients with orthostatic hypotension, balance disturbance associated with motor disability, or both examined three commercially available portable folding chairs. A questionnaire was used to document the characteristics in chair design that were relevant for satisfactory use to these patients. Armrests, seat width, and an adjustable sitting height were found to be important features of a portable folding chair. One chair was selected by 11 of 13 patients to fit most needs.

  13. Patients' choice of portable folding chairs to reduce symptoms of orthostatic hypotension

    NASA Technical Reports Server (NTRS)

    Smit, A. A.; Wieling, W.; Opfer-Gehrking, T. L.; van Emmerik-Levelt, H. M.; Low, P. A.

    1999-01-01

    Patients with neurogenic orthostatic hypotension may use portable folding chairs to prevent or reduce symptoms of low blood pressure. However, a concomitant movement disorder may limit the use of these chairs in daily living. In this prospective study, 13 patients with orthostatic hypotension, balance disturbance associated with motor disability, or both examined three commercially available portable folding chairs. A questionnaire was used to document the characteristics in chair design that were relevant for satisfactory use to these patients. Armrests, seat width, and an adjustable sitting height were found to be important features of a portable folding chair. One chair was selected by 11 of 13 patients to fit most needs.

  14. Bedside Ultrasound Reduces Diagnostic Uncertainty and Guides Resuscitation in Patients With Undifferentiated Hypotension.

    PubMed

    Shokoohi, Hamid; Boniface, Keith S; Pourmand, Ali; Liu, Yiju T; Davison, Danielle L; Hawkins, Katrina D; Buhumaid, Rasha E; Salimian, Mohammad; Yadav, Kabir

    2015-12-01

    Utilization of ultrasound in the evaluation of patients with undifferentiated hypotension has been proposed in several protocols. We sought to assess the impact of an ultrasound hypotension protocol on physicians' diagnostic certainty, diagnostic ability, and treatment and resource utilization. Prospective observational study. Emergency department in a single, academic tertiary care hospital. A convenience sample of patients with a systolic blood pressure less than 90 mm Hg after an initial fluid resuscitation, who lacked an obvious source of hypotension. An ultrasound-trained physician performed an ultrasound on each patient using a standardized hypotension protocol. Differential diagnosis and management plan was solicited from the treating physician immediately before and after the ultrasound. Blinded chart review was conducted for management and diagnosis during the emergency department and inpatient hospital stay. The primary endpoints were the identification of an accurate cause for hypotension and change in physicians' diagnostic uncertainty. The secondary endpoints were changes in treatment plan, use of resources, and changes in disposition after performing the ultrasound. One hundred eighteen patients with a mean age of 62 years were enrolled. There was a significant 27.7% decrease in the mean aggregate complexity of diagnostic uncertainty before and after the ultrasound hypotension protocol (1.85-1.34; -0.51 [95% CI, -0.41 to -0.62]) as well as a significant increase in the absolute proportion of patients with a definitive diagnosis from 0.8% to 12.7%. Overall, the leading diagnosis after the ultrasound hypotension protocol demonstrated excellent concordance with the blinded consensus final diagnosis (Cohen k = 0.80). Twenty-nine patients (24.6%) had a significant change in the use of IV fluids, vasoactive agents, or blood products. There were also significant changes in major diagnostic imaging (30.5%), consultation (13.6%), and emergency department

  15. [Hemodynamic mechanism of the hypotensive action of beta-phenyl-GABA esters (phenibut)].

    PubMed

    Tiurenkov, I N

    1983-01-01

    It was established in acute and chronic experiments on cats that phenibut ethers are 7-10 times more potent than phenibut itself as regards hypotensive activity and produce inconsistent effects on the cardio- and hemodynamics. Of these ethers, methyl ether of phenibut is the most powerful agent. It causes lasting hypotension when given in doses of 1/50 and 1/30 of the LD50 at the cost of a decrease in the general peripheral resistance. At the same time, apart from raising the blood inflow to the heart and cardiac output, the drug has a compensated adverse ino- and chronotropic action on the heart.

  16. Hypotensive effect of Chamaemelum nobile aqueous extract in spontaneously hypertensive rats.

    PubMed

    Zeggwagh, Naoufel Ali; Moufid, Abderahman; Michel, Jean Baptiste; Eddouks, Mohamed

    2009-07-01

    This study aims to evaluate the hypotensive effect of Chamaemelum nobile aqueous extract (CNAE) in spontaneously hypertensive rats (SHRs). Single oral administration of CNAE (140 mg/kg) produced a significant reduction (p < 0.05) in systolic blood pressure (SBP) after 24 h of the administration. Daily oral administration of CNAE (140 mg/kg) during 3 weeks produced a significant reduction in SBP in the day 8 (p < 0.01) of treatment. Furthermore, CNAE produced a significant increase in urinary output and electrolytes excretion (p < 0.01) from the day 8 to the end of treatment. We conclude that CNAE possesses a hypotensive and diuretic effect in SHR.

  17. 19 CFR 134.21 - Special marking.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... COUNTRY OF ORIGIN MARKING Marking of Containers or Holders § 134.21 Special marking. This subpart includes only country of origin marking requirements and exceptions under section 304(b), Tariff Act of 1930,...

  18. 46 CFR 160.064-4 - Marking.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... manufacturer or distributor). (Lot No.). (b) Durability of marking. Marking shall be of a type which will be... instructions for use. (b) Durability of marking. Marking must be of a type which will be durable and legible...

  19. Inflectional marking in Hungarian aphasics.

    PubMed

    MacWhinney, B; Osmán-Sági, J

    1991-08-01

    How do aphasics deal with the rich inflectional marking available in agglutinative languages like Hungarian? For the Hungarian noun alone, aphasics have to deal with over 15 basic case markings and dozens of possible combinations of these basic markings. Using the picture description task of MacWhinney and Bates (1978), this study examined the use of inflectional markings in nine Broca's and five Wernicke's aphasic speakers of Hungarian. The analysis focused on subject, direct object, indirect object, and locative nominal arguments. Compared to normals, both groups had a much higher rate of omission of all argument types. Subject ellipsis was particularly strong, as it is in normal Hungarian. There was a tendency for Broca's to omit the indirect object and for Wernicke's to omit the direct object. Across argument types, Wernicke's had a much higher level of pronoun usage than did Broca's. Broca's also showed a very high level of article omission. Compared to similar data reported by Slobin (this issue) for Turkish, the Hungarian aphasics showed an elevated level of omission of case markings. Addition errors were quite rare, but there were 14 substitutions of one case marking for another. These errors all involved the substitution of some close semantic competitor. There were no errors in the basic rules for vowel harmony or morpheme order. Overall the results paint a picture of a group of individuals whose grammatical abilities are damaged and noisy, but still largely functional. Neither the view of Broca's as agrammatic nor the view of Wernicke's as paragrammatic was strongly supported.

  20. Histopathological analysis of spontaneous large necrosis of adrenal pheochromocytoma manifested as acute attacks of alternating hypertension and hypotension: a case report.

    PubMed

    Ohara, Nobumasa; Uemura, Yasuyuki; Mezaki, Naomi; Kimura, Keita; Kaneko, Masanori; Kuwano, Hirohiko; Ebe, Katsuya; Fujita, Toshio; Komeyama, Takeshi; Usuda, Hiroyuki; Yamazaki, Yuto; Maekawa, Takashi; Sasano, Hironobu; Kaneko, Kenzo; Kamoi, Kyuzi

    2016-10-12

    Pheochromocytomas are rare catecholamine-producing neuroendocrine tumors. Hypertension secondary to pheochromocytoma is often paroxysmal, and patients occasionally present with sudden attacks of alternating hypertension and hypotension. Spontaneous, extensive necrosis within the tumor that is associated with catecholamine crisis is an infrequent complication of adrenal pheochromocytoma, but its pathogenesis remains unclear. A 69-year-old Japanese man developed acute-onset episodic headaches, palpitations, and chest pains. During the episodes, both marked fluctuations in blood pressure (ranging from 40/25 to 300/160 mmHg) and high plasma levels of catecholamines were found simultaneously. Radiological findings indicated a 4-cm left adrenal pheochromocytoma. These episodic symptoms disappeared within 2 weeks with normalization of plasma catecholamine levels. Two months later, the patient underwent adrenalectomy. Microscopic examinations revealed pheocromocytoma with a large central area of coagulative necrosis. The necrotic material was immunohistochemically positive for chromogranin A. Granulation tissue was adjacent to the necrotic area, accompanied by numerous hemosiderin-laden macrophages and histiocytes with vascular proliferation. Viable tumor cells, detected along the periphery of the tumor, demonstrated pyknosis, and the Ki-67 labeling index was 2 % in the hot spot. No embolus or thrombus formation was found in the resected specimen harboring the whole tumor. The Pheochromocytoma of the Adrenal gland Scaled Score was 2 out of 20. The patient's postoperative course was unremarkable for > 7 years. Presumed causal factors for the extensive necrosis of adrenal pheochromocytoma in previously reported cases include hemorrhage into the tumor, hypotension induced by a phentolamine administration, embolic infarction, high intracapsular pressure due to malignant growth of the tumor, and catecholamine-induced vasoconstriction. In the present case, histopathological

  1. L-653,328: an ocular hypotensive agent with modest beta receptor blocking activity

    SciTech Connect

    Sugrue, M.F.; Gautheron, P.; Grove, J.; Mallorga, P.; Viader, M.P.; Baldwin, J.J.; Ponticello, G.S.; Varga, S.L.

    1988-05-01

    L-653,328 is the acetate ester of L-652,698 ((S)-3-tert-butylamino-1-(4-(2(hydroxy)ethyl)phenoxy)2-propanol). The penetration of L-652,698 into the albino rabbit eye was enhanced when the compound was instilled as its prodrug acetate ester. The instillation (one drop of 50 microliter) of 0.01, 0.05 and 0.1% solutions of L-653,328 significantly decreased in a dose-dependent manner the elevated intraocular pressure (IOP) of alpha-chymotrypsinized rabbits by 3.2, 4.7 and 6.1 mm Hg, respectively. A 0.01% solution of L-652,698 failed to significantly lower IOP, whereas this dose of timolol (3.8 mm Hg) and betaxolol (3.3 mm Hg) was effective. L-652,698 was active at 0.05% and 0.1%. Extraocular beta-adrenoceptor blockade was quantified in ganglion-blocked, conscious rabbits by determining effects on heart rate and blood pressure changes to i.v. isoproterenol (0.5 microgram/kg). Doses of timolol blocking isoproterenol-induced hypotension and tachycardia by 50% were 0.0065% and 0.03%, respectively. The corresponding doses for betaxolol were greater than 3% (43% inhibition) and 0.3%. Heart rate and blood pressure changes to isoproterenol were blocked by 18 and 36%, respectively, after the instillation of a 3% solution of L-653,328. The reduced propensity of L-653,328 for extraocular beta-adrenoceptor blockade stems from the modest affinity of L-652,698, its active moiety, for beta-adrenoceptors. The Ki values of L-652,698 for displacement of 125I-iodocyanopindolol binding to beta 1-(left ventricle) and beta 2-binding sites (iris + ciliary body) in the rabbit were 5.7 microM and 7.3 microM, respectively. In marked contrast, the corresponding values for timolol were 12 nM and 1.8 nM.

  2. Transient severe hypotension with once-weekly subcutaneous injection of teriparatide in osteoporotic patient: a case report and insight for the drug interaction between hypotensive agents and teriparatide.

    PubMed

    Enishi, Tetsuya; Uemura, Hirokazu; Katoh, Shinsuke; Inatsugi, Masanori; Minato, Sho; Inatsugi, Kei; Inatsugi, Mikiko; Sato, Nori; Siryo, Koichi

    2015-01-01

    Teriparatide, a recombinant form of parathyroid hormone, were well recognized as a useful option for the treatment of the osteoporosis. Although some side effects of teriparatide include headache, nausea, dizziness, and limb pain were reported. Here we present a 80-year-old woman of transient asymptomatic hypotension with once-weekly subcutaneous injection of teriparatide for the treatment of osteoporosis with hypertension disease as acute-phase reactions. Systolic blood pressure decreased in both 30 min and 60 min after injection compared with before injection. Heart rate increased with passage of time. Statistically significant were observed among before, 30 min, 60 min after injection of teriparatide. Slight nausea was seen as subjective symptoms with the first and second injection after 30 min. This case indicates careful attention, at least 1 hr, was recommended with weekly subcutaneous injections of teriparatide in the treatment for osoteoproteic patient with hypertension decreases. This is a first report, to the best of our knowledge, to demonstrate the transient asymptomatic hypotension after once-weekly injection of teriparatide with hypertension disease. Transient hypotension occurred after injection of teriparatide during the treatment period and was asymptomatic except for the first 2 injections.

  3. Survival analysis of hypotensive cats admitted to an intensive care unit with or without hyperlactatemia: 39 cases (2005-2011).

    PubMed

    Shea, Emily K; Dombrowski, Stefan C; Silverstein, Deborah C

    2017-04-15

    OBJECTIVE To examine the association between blood lactate concentration and survival to hospital discharge in critically ill hypotensive cats. DESIGN Retrospective case series. ANIMALS 39 cats admitted to an intensive care unit of a university veterinary hospital between January 2005 and December 2011 for which blood lactate concentration was recorded ≤ 1 hour before or after a Doppler-derived arterial blood pressure measurement ≤ 90 mm Hg (ie, hypotension) was obtained. PROCEDURES Medical records of each cat were reviewed to assess survival to hospital discharge, illness severity, duration of hospitalization, age, body weight, and PCV. Results were compared between hypotensive cats with and without hyperlactatemia (blood lactate concentration ≥ 2.5 mmol/L). RESULTS 6 of 39 (15%) hypotensive cats survived to hospital discharge. Twelve (31%) cats were normolactatemic (blood lactate concentration < 2.5 mmol/L), and 27 (69%) were hyperlactatemic. Hypotensive cats with normolactatemia had a higher blood pressure and higher survival rate than hypotensive cats with hyperlactatemia. Five-day Kaplan-Meier survival rates were 57% for normolactatemic cats and 17% for hyperlactatemic cats. Age, body weight, duration of hospitalization, PCV, and illness severity did not differ significantly between hypotensive cats with and without hyperlactatemia. CONCLUSIONS AND CLINICAL RELEVANCE Hypotensive, normolactatemic cats in an intensive care unit had a significantly greater chance of survival to hospital discharge than their hyperlactatemic counterparts. Blood lactate concentration may be a useful prognostic indicator for this patient population when used in conjunction with other clinical and laboratory findings.

  4. Severe hypotension related to high negative pressure suction drainage on a thoracic epidural drain during multilevel spinal fixation.

    PubMed

    Brahmbhatt, Anjalee; Hall, Nicholas D P; Bradley, William Pierre Litherland

    2013-11-15

    Hypotension or bradycardia or both related to intracranial hypotension after craniotomy has been reported in the literature. However, such reports are uncommon with thoracic epidural drains. We describe a case in which application of high negative pressure suction to a thoracic epidural drain caused a sudden decrease in arterial blood pressure.

  5. Mean arterial pressure and systolic blood pressure for detection of hypotension during hemapheresis: implications for patients with baseline hypertension.

    PubMed

    Miller, Matthew C; Rosales, Lazaro G; Kelly, Karen C; Henry, John Bernard

    2005-10-01

    Mean arterial pressure (MAP) has been characterized as a more sensitive and physiologically appropriate hemodynamic parameter in the detection of hemapheresis-related hypotension, resulting in a much closer correlation with the presence of symptomatic hypotension. Patients were enrolled over a 12-month period and data collected on any previous diagnosis of hypertension, antihypertensive therapy used, indication for apheresis, age decile, and gender. Baseline vital signs, any hypotensive signs or symptoms observed, and the patient's vital signs at the time of any hypotensive episode were recorded. Patients were assigned to a subgroup, sensitivity and specificity analysis performed, positive likelihood ratios calculated, receiver operating characteristic curves constructed, and ideal cutoff values identified. The incidence of hypotension among our study population was found to be 6.8%. Over all procedures, systolic blood pressure (SBP) was determined to be a "poor" test for detecting hypotension, while MAP demonstrated a "fair" capacity. A downward normalization was evident in the ideal cutoff value based upon a patient's hypertensive history. The currently accepted SBP less than 80 mmHg cutoff failed to detect hypotensive episodes among baseline hypertensive patients, raising questions about its sensitivity. Based upon physiologic principles and study findings, a MAP-based criterion is preferable in the diagnosis of hypotension during hemapheresis. Copyright 2005 Wiley-Liss, Inc

  6. Cerebral vasospasm following intracranial hypotension caused by cerebrospinal fluid leak from an incidental lumbar durotomy. Case report.

    PubMed

    Chaves, Claudia; Freidberg, Stephen R; Lee, Grace; Zerris, Vasilios; Ries, Sarah; Chavali, Ram

    2005-01-01

    The authors report on the unusual case of a patient with intracranial hypotension following an incidental durotomy complicated by an extensive but reversible cerebral vasospasm. Despite the dural tear repair and correction of the intracranial hypotension, the vasospasm ran its course. The precise mechanism of the cerebral vasospasm in this patient is unclear.

  7. Changes of some amino acid concentrations in the medial vestibular nucleus of conscious rats following acute hypotension.

    PubMed

    Li, Xiang-Lan; An, Ying; Jin, Qing-Hua; Kim, Min Sun; Park, Byung Rim; Jin, Yuan-Zhe

    2010-06-14

    Microdialysis and high performance liquid chromatography (HPLC) were used to measure the changes of certain amino acids in the medial vestibular nucleus (MVN) of conscious rats in order to understand whether those amino acids are involved in the regulation of blood pressure. Acute hypotension was induced by infusing sodium nitroprusside (SNP) into the femoral vein. In the control group, glutamate (Glu) release increased, though gamma-aminobutyric acid (GABA) and taurine (Tau) release decreased in the MVN following acute hypotension. In the unilateral labyrinthectomy group, the levels of Glu, GABA, and Tau were unchanged in the ipsilateral MVN to the lesion following acute hypotension. Furthermore, in the contralateral MVN to the lesion, Glu release increased, and GABA and Tau release decreased following acute hypotension. These results suggest that SNP-induced acute hypotension can influence the activity of neurons in the MVN through afferent signals from peripheral vestibular receptors, and that certain amino acid transmitters in the MVN are involved in this process.

  8. The pupillary light reflex for predicting the risk of hypotension after spinal anaesthesia for elective caesarean section.

    PubMed

    Riffard, Céline; Viêt, Truong Quoc; Desgranges, François-Pierrick; Bouvet, Lionel; Allaouchiche, Bernard; Stewart, Adrienne; Chassard, Dominique

    2016-12-19

    The balance between the sympathetic and parasympathetic systems could be used to predict the onset of hypotension following spinal anaesthesia. The autonomic innervation of the pupil may reflect this balance. The aim of this study was to evaluate the ability of pupillometry to predict the risk of hypotension after spinal anaesthesia for caesarean section. Two hundred patients receiving spinal anaesthesia for caesarean section were recruited. Changes in pupillary diameter, pupillary reaction latency, pupil constriction velocity and maximum and minimum pupillary diameters were measured with a pupillometer (Neurolight(®), IDMed) prior to induction of spinal anaesthesia with 10mg bupivacaine and fentanyl 30μg. Hypotension was defined as a systolic blood pressure drop of > 20% compared with the baseline value. A total of 141 patients (70%) presented at least one episode of hypotension. Pupillary reaction latency can poorly predict hypotension and severe hypotension after spinal anaesthesia. The areas under the receiver-operating characteristic curves were 0.654 (95% confidence interval: 0.584-0.720, P=0.0001) and 0.633 (95% confidence interval: 0.562-0.700, P=0.004) for optimal threshold values of 223 and 231ms, respectively. In multivariate analysis, a baseline systolic blood pressure > 130mmHg (odds ratio: 1.98, P=0.04) and a PRL > 223ms (odds ratio: 3.42, P=0.0002) were independently associated with the risk of spinal anaesthesia-related hypotension. Following spinal anaesthesia in patients undergoing caesarean section, though the predictive capacity pupillary reaction latency for the onset of hypotension and severe hypotension is poor, it is nevertheless the strongest predictor of hypotension identified in our study. Copyright © 2016 Société française d'anesthésie et de réanimation (Sfar). Published by Elsevier Masson SAS. All rights reserved.

  9. Intracranial hypotension in the setting of concurrent perineural cyst rupture and subarachnoid hemorrhage.

    PubMed

    Sivakumar, Walavan; Ravindra, Vijay M; Cutler, Aaron; Couldwell, William T

    2014-06-01

    Although most patients with intracranial hypotension typically present with headaches, the rest of the clinical spectrum is characteristically non-specific and often quite variable. In a patient with concurrent pathologies that can produce a similar clinical picture, a high index of suspicion must be maintained to achieve the correct diagnosis. The authors report a patient with intracranial hypotension in the setting of concurrent perineural cyst rupture and subarachnoid hemorrhage. A 63-year-old woman with a family history of ruptured intracranial aneurysms presented after a sudden thunderclap headache and was found to have diffuse subarachnoid hemorrhage. Imaging revealed anterior communicating and superior hypophyseal artery aneurysms. Following the uneventful clipping of both aneurysms, the patient experienced a delayed return to her neurological baseline. After it was noted that the patient had an improved neurological examination when she was placed supine, further investigation confirmed intracranial hypotension from perineural cyst rupture. The patient improved and returned to her neurological baseline after undergoing a high-volume blood patch and remained neurologically intact at postoperative follow-up. Although intracranial hypotension is known to be commonly associated with cerebrospinal fluid leak, its causal and temporal relationship with subarachnoid hemorrhage has yet to be elucidated.

  10. Effects of hemorrhagic hypotension on tyrosine concentrations in rat spinal cord and plasma

    NASA Technical Reports Server (NTRS)

    Conlay, L. A.; Maher, T. J.; Roberts, C. H.; Wurtman, R. J.

    1988-01-01

    Tyrosine is the precursor for catecholamine neurotransmitters. When catecholamine-containing neurons are physiologically active (as sympathoadrenal cells are in hypotension), tyrosine administration increases catecholamine synthesis and release. Since hypotension can alter plasma amino acid composition, the effects of an acute hypotensive insult on tyrosine concentrations in plasma and spinal cord were examined. Rats were cannulated and bled until the systolic blood pressure was 50 mmHg, or were kept normotensive for 1 h. Tyrosine and other large neutral amino acids (LNAA) known to compete with tyrosine for brain uptake were assayed in plasma and spinal cord. The rate at which intra-arterial (H-3)tyrosine disappeared from the plasma was also estimated in hemorrhaged and control rats. In plasma of hemorrhaged animals, both the tyrosine concentration and the tyrosine/LNAA ratio was elevated; moreover, the disappearance of (H-3)tyrosine was slowed. Tyrosine concentrations also increased in spinal cords of hemorrhaged-hypotensive rats when compared to normotensive controls. Changes in plasma amino acid patterns may thus influence spinal cord concentrations of amino acid precursors for neurotransmitters during the stress of hemorrhagic shock.

  11. Hypovolemia-induced Orthostatic Hypotension Relates To Hypo-sympathetic Responsiveness

    NASA Technical Reports Server (NTRS)

    Meck, Janice V.

    2007-01-01

    We report a new model which uses hypovolemia to force humans into a hemodynamic state that is similar to that after spaceflight. This model can be used to test candidate countermeasures for postflight orthostatic hypotension and to identify crewmembers who will be most susceptible to that symptom on landing day.

  12. Histamine-Induced Hypotension Modified by H1 and H2 Antagonists.

    DTIC Science & Technology

    The hypotensive response of monkeys to exogenous histamine was measured when the histamine was given without antagonist, after chlorpheniramine (10...percent maximal response was: without antagonist, 0.115 micrograms/kg; after chlorpheniramine , 13.5 micrograms/kg; after chlorpheniramine and

  13. In vivo arginine production and intravascular nitric oxide synthesis in hypotensive sepsis

    USDA-ARS?s Scientific Manuscript database

    Arginine is important in the response to infections and is a precursor for the synthesis of the vasodilator nitric oxide (NO). Low plasma arginine is correlated with a worse prognosis in patients with sepsis, and increased NO has been implicated in the hypotension of sepsis. Data on in vivo arginine...

  14. Blood pressure lowering therapy in older people: Does it really cause postural hypotension or falls?

    PubMed

    Zia, Anam; Kamaruzzaman, Shahrul Bahyah; Tan, Maw Pin

    2015-03-01

    Hypertension is a highly prevalent condition among older people, but many physicians avoid aggressive treatment in this age group due to concerns about adverse effects such as orthostatic hypotension and falls. Orthostatic hypotension, which also increases in prevalence with increasing age, has been considered to be associated with antihypertensive therapy. Both orthostatic hypotension and antihypertensive medications are considered independent yet closely related predictors for falls among older people. The prescription of antihypertensive therapy among the elderly remains a long-standing controversy in geriatric medicine due to ongoing concerns about potential complications such as falls, despite conclusive evidence supporting the treatment of hypertension even among the very elderly. However, recent evidence suggests a dose-dependent relationship between blood pressure lowering therapy and falls among older individuals with preexisting risk factors for falls. In response to the spate of revisions in hypertension treatment targets for older patients in international guidelines and the recent evidence on antihypertensive therapy and falls, this review article examines the complex relationship between hypertension, antihypertensives, orthostatic hypotension, and falls among older patients.

  15. Essential Hypotension Is Accompanied by Deficits in Attention and Working Memory

    ERIC Educational Resources Information Center

    Duschek, Stefan; Matthias, Ellen; Schandry, Rainer

    2005-01-01

    In the present study, the authors investigated the relationship between low blood pressure (BP) and attentional performance through the application of a multidimensional diagnostic approach. The authors compared 40 subjects with essential hypotension (mean systolic BP = 97.6 mmHg) with 40 normotensive controls (mean systolic BP = 124.1 mmHg) using…

  16. New NANN Practice Guideline: the management of hypotension in the very-low-birth-weight infant.

    PubMed

    Vargo, Lyn; Seri, Istvan

    2011-08-01

    The Management of Hypotension in the Very-Low-Birth-Weight Infant: Guideline for Practice, developed by Lyn Vargo, PhD, RN, NNP-BC, and Istvan Seri, MD, PhD, in 2011 under the auspices of the National Association of Neonatal Nurse Practitioners, focuses on the challenging topic of clinical management of systemic hypotension in the very low-birth-weight (VLBW) infant during the first 3 days of postnatal life. The recommendations and rationale in the excerpt below from the complete online publication are based on the best evidence available through both neonatal research and consultation of experts on the subject. They suggest a conservative, evidence-based treatment approach for the management of hypotension in the VLBW infant during the first 3 days of postnatal life that is logical, safe, and physiologically sound. The insufficient fund of knowledge on transitional cardiovascular physiology in general and pathophysiology in particular makes establishment of strict guidelines on the treatment of hypotension in VLBW neonates impossible. What becomes clear when presenting the evidence is how much more we need to know. Readers are strongly encouraged to refer to the complete text of the guideline, which has been endorsed by the American Academy of Pediatrics, for further understanding of this complex topic. The guideline is available free of charge at www.nann.org (click on Guidelines in the Education section).

  17. Hypotension in patients on chronic peritoneal dialysis: etiology, management, and outcome.

    PubMed

    Malliara, Maria; Passadakis, Ploumis; Panagoutsos, Stylianos; Theodoridis, Marios; Thodis, Elias; Bargman, Joanne; Jassal, Vanita; Vas, Stephen; Vargemezis, Vassilios; Oreopoulos, Dimitrios

    2002-01-01

    We retrospectively evaluated the phenomenon of arterial hypotension in peritoneal dialysis (PD) in a large cohort of 633 PD patients from two centers (Toronto Western Hospital, Toronto, Canada, and Division of Nephrology, Democritus University of Thrace, Greece), thus extending our previously reported experience for an additional 6 years (1995-2000). Together, the units had 81 hypotensive patients (12.8%), whose mean age was 63.8 +/- 14.2 years and whose mean duration of peritoneal dialysis was 49.3 +/- 30 months. Based on the underlying pathophysiology, the hypotensive PD patients were divided into four groups: (A) hypovolemia, 32 patients (39.5%); (B) congestive heart failure (CHF), 15 patients (18.5%); (C) receiving antihypertensive medications, 11 patients (13.6%); and (D) "unknown" etiology, 23 patients (28.4%). All patients in the hypovolemic and antihypertensive groups responded well to treatment (volume expansion and discontinuation of antihypertensive medication, respectively), but in the CHF and "unknown" groups, only 40% improved with the appropriate intervention. Patients in the latter two groups showed the poorest prognosis, with an approximate death rate of 65%. The hypovolemic group had better outcomes, which might reflect prompt response to fluid replacement in that group. We conclude that, in PD patients, careful use of antihypertensive medication, the right evaluation of target weight (especially in patients with cardiac failure), and judicious use of hypertonic exchanges may prevent the severe complication of arterial hypotension.

  18. [Evaluation of urine specific gravity as an index of hypotension after spinal anesthesia for cesarean section].

    PubMed

    Sudani, Tomoko; Inoue, Chieko; Nishimura, Kazumi; Takada, Motoshi; Suzuki, Akira; Dohi, Shuji

    2010-04-01

    Although most cesarean sections are done under spinal anesthesia, we often experience severe hypotension. Fluid resuscitation is usually carried out for prevention of hypotension, but it is difficult to assess the suitable infusion volume. We examined whether the urine specific gravity can predict hypotension after spinal anesthesia for cesarean section. Ninety nine patients (ASA 1 or 2) undergoing elective cesarean section were recruited. After dural puncture, we collected the cerebrospinal fluid and injected 2 ml of hyperbaric 0.5% bupivacaine. Thereafter urethral catheters were inserted, and then we collected the urine sample. The specific gravity of each sample was measured by using refractometer after the operation. There was a good correlation between the urinary output and the urine specific gravity. The minimum systolic blood pressure until delivery, the total dose of ephedrine, and the maximum sensory block level showed a significant, but not particularly strong correlation with the urine specific gravity. We concluded that it was difficult to predict hypotension by using urine specific gravity because the correlation was too weak.

  19. Dynamic regulation of heart rate during acute hypotension: new insight into baroreflex function

    NASA Technical Reports Server (NTRS)

    Zhang, R.; Behbehani, K.; Crandall, C. G.; Zuckerman, J. H.; Levine, B. D.; Blomqvist, C. G. (Principal Investigator)

    2001-01-01

    To examine the dynamic properties of baroreflex function, we measured beat-to-beat changes in arterial blood pressure (ABP) and heart rate (HR) during acute hypotension induced by thigh cuff deflation in 10 healthy subjects under supine resting conditions and during progressive lower body negative pressure (LBNP). The quantitative, temporal relationship between ABP and HR was fitted by a second-order autoregressive (AR) model. The frequency response was evaluated by transfer function analysis. Results: HR changes during acute hypotension appear to be controlled by an ABP error signal between baseline and induced hypotension. The quantitative relationship between changes in ABP and HR is characterized by a second-order AR model with a pure time delay of 0.75 s containing low-pass filter properties. During LBNP, the change in HR/change in ABP during induced hypotension significantly decreased, as did the numerator coefficients of the AR model and transfer function gain. Conclusions: 1) Beat-to-beat HR responses to dynamic changes in ABP may be controlled by an error signal rather than directional changes in pressure, suggesting a "set point" mechanism in short-term ABP control. 2) The quantitative relationship between dynamic changes in ABP and HR can be described by a second-order AR model with a pure time delay. 3) The ability of the baroreflex to evoke a HR response to transient changes in pressure was reduced during LBNP, which was due primarily to a reduction of the static gain of the baroreflex.

  20. Dynamic regulation of heart rate during acute hypotension: new insight into baroreflex function

    NASA Technical Reports Server (NTRS)

    Zhang, R.; Behbehani, K.; Crandall, C. G.; Zuckerman, J. H.; Levine, B. D.; Blomqvist, C. G. (Principal Investigator)

    2001-01-01

    To examine the dynamic properties of baroreflex function, we measured beat-to-beat changes in arterial blood pressure (ABP) and heart rate (HR) during acute hypotension induced by thigh cuff deflation in 10 healthy subjects under supine resting conditions and during progressive lower body negative pressure (LBNP). The quantitative, temporal relationship between ABP and HR was fitted by a second-order autoregressive (AR) model. The frequency response was evaluated by transfer function analysis. Results: HR changes during acute hypotension appear to be controlled by an ABP error signal between baseline and induced hypotension. The quantitative relationship between changes in ABP and HR is characterized by a second-order AR model with a pure time delay of 0.75 s containing low-pass filter properties. During LBNP, the change in HR/change in ABP during induced hypotension significantly decreased, as did the numerator coefficients of the AR model and transfer function gain. Conclusions: 1) Beat-to-beat HR responses to dynamic changes in ABP may be controlled by an error signal rather than directional changes in pressure, suggesting a "set point" mechanism in short-term ABP control. 2) The quantitative relationship between dynamic changes in ABP and HR can be described by a second-order AR model with a pure time delay. 3) The ability of the baroreflex to evoke a HR response to transient changes in pressure was reduced during LBNP, which was due primarily to a reduction of the static gain of the baroreflex.

  1. Profound Hypotension after an Intradermal Injection of Indigo Carmine for Sentinel Node Mapping

    PubMed Central

    Jo, Youn Yi; Lee, Mi Geum; Yun, Soon Young

    2013-01-01

    Intradermal injections of indigo carmine for sentinel node mapping are considered safe and no report of an adverse reaction has been published. The authors described two cases of profound hypotension in women that underwent breast-conserving surgery after an intradermal injection of indigo carmine into the periareolar area for sentinel node mapping. PMID:23593094

  2. Profound hypotension after an intradermal injection of indigo carmine for sentinel node mapping.

    PubMed

    Jo, Youn Yi; Lee, Mi Geum; Yun, Soon Young; Lee, Kyung Cheon

    2013-03-01

    Intradermal injections of indigo carmine for sentinel node mapping are considered safe and no report of an adverse reaction has been published. The authors described two cases of profound hypotension in women that underwent breast-conserving surgery after an intradermal injection of indigo carmine into the periareolar area for sentinel node mapping.

  3. Regional redistribution of blood flow in the external and internal carotid arteries during acute hypotension.

    PubMed

    Ogoh, Shigehiko; Lericollais, Romain; Hirasawa, Ai; Sakai, Sadayoshi; Normand, Hervé; Bailey, Damian M

    2014-05-15

    The present study examined to what extent an acute bout of hypotension influences blood flow in the external carotid artery (ECA) and the corresponding implications for blood flow regulation in the internal carotid artery (ICA). Nine healthy male participants were subjected to an abrupt decrease in arterial pressure via the thigh-cuff inflation-deflation technique. Duplex ultrasound was employed to measure beat-to-beat ECA and ICA blood flow. Compared with the baseline normotensive control, acute hypotension resulted in a heterogeneous blood flow response. ICA blood flow initially decreased following cuff release and then returned quickly to baseline levels. In contrast, the reduction in ECA blood flow persisted for 30 s following cuff release. Thus, the contribution of common carotid artery blood flow to the ECA circulation decreased during acute hypotension (-10 ± 4%, P < 0.001). This finding suggests that a preserved reduction in ECA blood flow, as well as dynamic cerebral autoregulation likely prevent a further decrease in intracranial blood flow during acute hypotension. The peripheral vasculature of the ECA may, thus, be considered an important vascular bed for intracranial cerebral blood flow regulation.

  4. Essential Hypotension Is Accompanied by Deficits in Attention and Working Memory

    ERIC Educational Resources Information Center

    Duschek, Stefan; Matthias, Ellen; Schandry, Rainer

    2005-01-01

    In the present study, the authors investigated the relationship between low blood pressure (BP) and attentional performance through the application of a multidimensional diagnostic approach. The authors compared 40 subjects with essential hypotension (mean systolic BP = 97.6 mmHg) with 40 normotensive controls (mean systolic BP = 124.1 mmHg) using…

  5. Influence of population and exercise protocol characteristics on hemodynamic determinants of post-aerobic exercise hypotension.

    PubMed

    Brito, L C; Queiroz, A C C; Forjaz, C L M

    2014-08-01

    Due to differences in study populations and protocols, the hemodynamic determinants of post-aerobic exercise hypotension (PAEH) are controversial. This review analyzed the factors that might influence PAEH hemodynamic determinants, through a search on PubMed using the following key words: "postexercise" or "post-exercise" combined with "hypotension", "blood pressure", "cardiac output", and "peripheral vascular resistance", and "aerobic exercise" combined only with "blood pressure". Forty-seven studies were selected, and the following characteristics were analyzed: age, gender, training status, body mass index status, blood pressure status, exercise intensity, duration and mode (continuous or interval), time of day, and recovery position. Data analysis showed that 1) most postexercise hypotension cases are due to a reduction in systemic vascular resistance; 2) age, body mass index, and blood pressure status influence postexercise hemodynamics, favoring cardiac output decrease in elderly, overweight, and hypertensive subjects; 3) gender and training status do not have an isolated influence; 4) exercise duration, intensity, and mode also do not affect postexercise hemodynamics; 5) time of day might have an influence, but more data are needed; and 6) recovery in the supine position facilitates systemic vascular resistance decrease. In conclusion, many factors may influence postexercise hypotension hemodynamics, and future studies should directly address these specific influences because different combinations may explain the observed variability in postexercise hemodynamic studies.

  6. Intraspinal hemorrhage in spontaneous intracranial hypotension: link to superficial siderosis? Report of 2 cases.

    PubMed

    Schievink, Wouter I; Wasserstein, Philip; Maya, M Marcel

    2016-03-01

    Spontaneous intracranial hypotension due to a spinal CSF leak has become a well-recognized cause of headaches, but such spinal CSF leaks also are found in approximately half of patients with superficial siderosis of the CNS. It has been hypothesized that friable vessels at the site of the spinal CSF leak are the likely source of chronic bleeding in these patients, but such an intraspinal hemorrhage has never been visualized. The authors report on 2 patients with spontaneous intracranial hypotension and intraspinal hemorrhage, offering support for this hypothesis. A 33-year-old man and a 62-year-old woman with spontaneous intracranial hypotension were found to have a hemorrhage within the ventral spinal CSF collection and within the thecal sac, respectively. Treatment consisted of microsurgical repair of a ventral dural tear in the first patient and epidural blood patching in the second patient. The authors suggest that spontaneous intracranial hypotension should be included in the differential diagnosis of spontaneous intraspinal hemorrhage, and that the intraspinal hemorrhage can account for the finding of superficial siderosis when the CSF leak remains untreated.

  7. Role of angiotensin-converting enzyme 2/angiotensin-(1-7)/Mas axis in the hypotensive effect of azilsartan.

    PubMed

    Iwanami, Jun; Mogi, Masaki; Tsukuda, Kana; Wang, Xiao-Li; Nakaoka, Hirotomo; Ohshima, Kousei; Chisaka, Toshiyuki; Bai, Hui-Yu; Kanno, Harumi; Min, Li-Juan; Horiuchi, Masatsugu

    2014-07-01

    The possible counteracting effect of angiotensin (Ang)-converting enzyme (ACE)2/Ang-(1-7)/Mas axis against the ACE/Ang II/Ang II type 1 (AT1) receptor axis in blood pressure control has been previously described. We examined the possibility that this pathway might be involved in the anti-hypertensive effect of a newly developed AT1 receptor blocker (ARB), azilsartan, and compared azilsartan's effects with those of another ARB, olmesartan. Transgenic mice carrying the human renin and angiotensinogen genes (hRN/hANG-Tg) were given azilsartan or olmesartan. Systolic and diastolic blood pressure, as determined by radiotelemetry, were significantly higher in hRN/hANG-Tg mice than in wild-type (WT) mice. Treatment with azilsartan or olmesartan (1 or 5 mg kg(-1) per day) significantly decreased systolic and diastolic blood pressure, and the blood pressure-lowering effect of azilsartan was more marked than that of olmesartan. The urinary Na concentration decreased in an age-dependent manner in hRN/hANG-Tg mice. Administration of azilsartan or olmesartan increased urinary Na concentration, and this effect was weaker with olmesartan than with azilsartan. Azilsartan decreased ENaC-α mRNA expression in the kidney and decreased the ratio of heart to body weight. Olmesartan had a similar but less-marked effect. ACE2 mRNA expression was lower in the kidneys and hearts of hRN/hANG-Tg mice than in WT mice. This decrease in ACE2 mRNA expression was attenuated by azilsartan, but not by olmesartan. These results suggest that the hypotensive and anti-hypertrophic effects of azilsartan may involve activation of the ACE2/Ang-(1-7)/Mas axis with AT1 receptor blockade.

  8. Neurogenic orthostatic hypotension: a double-blind, placebo-controlled study with midodrine

    NASA Technical Reports Server (NTRS)

    Jankovic, J.; Gilden, J. L.; Hiner, B. C.; Kaufmann, H.; Brown, D. C.; Coghlan, C. H.; Rubin, M.; Fouad-Tarazi, F. M.

    1993-01-01

    PURPOSE: To investigate the efficacy and safety of midodrine for treatment of patients with orthostatic hypotension due to autonomic failure. PATIENTS: Ninety-seven patients with orthostatic hypotension were randomized in a 4-week, double-blinded, placebo-controlled study with a 1-week placebo run-in period. Patients ranged in age from 22 to 86 years (mean: 61 years). METHODS: After a 1-week run-in phase, either placebo or midodrine at a dose of 2.5 mg, 5 mg, or 10 mg was administered three times a day for 4 weeks. Both the placebo group and the 2.5-mg midodrine group received constant doses throughout the double-blind phase. The patients receiving 5 mg or 10 mg of midodrine were given doses that were increased at weekly intervals by 2.5-mg increments until the designated dose was reached. Efficacy evaluations were based on an improvement at 1-hour postdose in standing systolic blood pressure and in symptoms of orthostatic hypotension (syncope, dizziness/lightheadedness, weakness/fatigue, and low energy level). RESULTS: Midodrine (10 mg) increased standing systolic blood pressure by 22 mm Hg (28%, p < 0.001 versus placebo). Midodrine improved (p < 0.05) the following symptoms of orthostatic hypotension compared to placebo: dizziness/lightheadedness, weakness/fatigue, syncope, low energy level, impaired ability to stand, and feelings of depression. The overall side effects were mainly mild to moderate. One or more side effects were reported by 22% of the placebo group compared with 27% of the midodrine-treated group. Scalp pruritus/tingling, which was reported by 10 of 74 (13.5%) of the midodrine-treated patients, was most frequent. Other reported side effects included supine hypertension (8%) and feelings of urinary urgency (4%). CONCLUSION: We conclude that midodrine is an effective and well-tolerated treatment for moderate-to-severe orthostatic hypotension associated with autonomic failure.

  9. Optimizing the respiratory pump: harnessing inspiratory resistance to treat systemic hypotension.

    PubMed

    Convertino, Victor A; Ryan, Kathy L; Rickards, Caroline A; Glorsky, Steven L; Idris, Ahamed H; Yannopoulos, Demetris; Metzger, Anja; Lurie, Keith G

    2011-06-01

    We review the physiology and affects of inspiration through a low level of added resistance for the treatment of hypotension. Recent animal and clinical studies demonstrated that one of the body's natural response mechanisms to hypotension is to harness the respiratory pump to increase circulation. That finding is consistent with observations, in the 1960s, about the effect of lowering intrathoracic pressure on key physiological and hemodynamic variables. We describe studies that focused on the fundamental relationship between the generation of negative intrathoracic pressure during inspiration through a low level of resistance created by an impedance threshold device and the physiologic sequelae of a respiratory pump. A decrease in intrathoracic pressure during inspiration through a fixed resistance resulting in a pressure difference of 7 cm H(2)O has multiple physiological benefits, including: enhanced venous return and cardiac stroke volume, lower intracranial pressure, resetting of the cardiac baroreflex, elevated cerebral blood flow oscillations, increased tissue blood flow/pressure gradient, and maintenance of the integrity of the baroreflex-mediated coherence between arterial pressure and sympathetic nerve activity. While breathing has traditionally been thought primarily to provide gas exchange, studies of the mechanisms involved in animals and humans provide the physiological underpinnings for "the other side of breathing": to increase circulation to the heart and brain, especially in the setting of physiological stress. The existing results support the use of the intrathoracic pump to treat clinical conditions associated with hypotension, including orthostatic hypotension, hypotension during and after hemodialysis, hemorrhagic shock, heat stroke, septic shock, and cardiac arrest. Harnessing these fundamental mechanisms that control cardiopulmonary physiology provides new opportunities for respiratory therapists and others who have traditionally focused on

  10. Pharmacological evidence of α2-adrenergic receptors in the hypotensive effect of Platonia insignis mart.

    PubMed

    Mendes, Marcelo Bezerra; da Silva-Filho, José Couras; Sabino, Carla Kelly Barroso; Arcanjo, Daniel Dias Rufino; Sousa, Cleyton Marcos Melo; Costa, Isabella Cristhina Gonçalves; Chaves, Mariana Helena; Oliveira, Rita de Cássia Meneses; Oliveira, Aldeídia P

    2014-10-01

    Platonia insignis Mart. (Clusiaceae) is a medicinal plant from the Brazilian Amazon region. The present study evaluated the biological potential of the ethanol extract (Pi-EtOH) and ethyl acetate fraction (Pi-EtOAc) of the P. insignis fruit shells on the cardiovascular system of rats. Pi-EtOH or Pi-EtOAc (12.5, 25, and 50 mg/kg) was administered intravenously in normotensive rats (260-300 g), and the mean arterial pressure and the heart rate were monitored. The Pi-EtOH induced hypotension (-11.56±0.89, -7.43±0.85, and -17.56±1.97 mmHg) followed by bradycardia in two highest doses (-8.89±3.62 and -15.79±1.83 beats/min) and Pi-EtOAc, at the same doses, induced hypotension (-11.2±1.03, -14.48±1.13, -29.89±2.67 mmHg) more intensively, followed by tachycardia at the dose 12.5 and 25 mg/kg (15.64±2.06, 19.31±1.92 beats/min) and bradycardia at a dose of 50 mg/kg (-9.98±7.33 beats/min). The hypotensive response from Pi-EtOAc was not attenuated when used in the pretreatment with L-NAME, verapamil, propranolol, and hexamethonium. However, when using yohimbine, the hypotensive effect was inhibited (-4.42±1.28 (P<.05), -3.29±0.99 (P<.05), 2.06±1.18 mmHg (P<.05); Student's t-test). Hence, the Pi-EtOAc seems to act similarly to the α2-adrenergic agonist in this hypotensive effect.

  11. Effect of perturbations and a meal on superior mesenteric artery flow in patients with orthostatic hypotension

    NASA Technical Reports Server (NTRS)

    Fujimura, J.; Camilleri, M.; Low, P. A.; Novak, V.; Novak, P.; Opfer-Gehrking, T. L.

    1997-01-01

    Our aims were to evaluate to role of superior mesenteric blood flow in the pathophysiology of orthostatic hypotension in patients with generalized autonomic failure. METHODS: Twelve patients with symptomatic neurogenic orthostatic hypotension and 12 healthy controls underwent superior mesenteric artery flow measurements using Doppler ultrasonography during head-up tilt and tilt plus meal ingestion. Autonomic failure was assessed using standard tests of the function of the sympathetic adrenergic, cardiovagal and postganglionic sympathetic sudomotor function. RESULTS: Superior mesenteric flow volume and time-averaged velocity were similar in patients and controls at supine rest; however, responses to cold pressor test and upright tilt were attenuated (p < 0.05) in patients compared to controls. Head-up tilt after the meal evoked a profound fall of blood pressure and mesenteric blood flow in the patients; the reduction of mesenteric blood flow correlated (r = 0.89) with the fall of blood pressure in these patients, providing another manifestation of failed baroreflexes. We make the novel finding that the severity of postprandial orthostatic hypotension regressed negatively with the postprandial increase in mesenteric flow in patients with orthostatic hypotension. CONCLUSION: Mesenteric flow is under baroreflex control, which when defective, results in, or worsens orthostatic hypotension. Its large size and baroreflexivity renders it quantitatively important in the maintenance of postural normotension. The effects of orthostatic stress can be significantly attenuated by reducing the splanchnic-mesenteric volume increase in response to food. Evaluation of mesenteric flow in response to eating and head-up tilt provide important information on intra-abdominal sympathetic adrenergic function, and the ability of the patient to cope with orthostatic stress.

  12. Induction of endothelium‐dependent constriction of mesenteric arteries in endotoxemic hypotensive shock

    PubMed Central

    Tseng, Tzu‐Ling; Chen, Mei‐Fang; Liu, Chin‐Hung; Pang, Cheng‐Yoong; Hsu, Yung‐Hsiang

    2016-01-01

    Background and Purpose Effective management of hypotension refractory to vasoconstrictors in severe sepsis is limited. A new strategy to ameliorate endotoxemic hypotension by inducing endothelium‐dependent constriction of large arteries was assessed. Experimental Approach Endotoxemia in rats was induced by injection of LPS (10 mg·kg−1, i.v.). Haemodynamics were measured in vivo, reactivity of isolated mesenteric arteries by myography and expression of proteins and enzyme activities by immunohistochemistry, biochemistry and molecular biology. Key ResultS Six hours after LPS, the hypotension was promptly reversed following injection (i.v. or i.p.) of oroxylin‐A (OroA) . In isolated LPS‐treated but not normal mesenteric arteries, OroA (1–10 μM) induced endothelium‐dependent, sustained constriction, blocked by endothelin‐1 (ET‐1) receptor antagonists. OroA further enhanced LPS‐induced expression of endothelin‐converting enzyme, ET‐1 mRNA and proteins and ET‐1 release, OroA also enhanced phosphorylation of Rho‐associated protein kinase (ROCK) and reversed LPS‐induced suppression of RhoA activities in smooth muscle of arteries with endothelium. Activated‐ phosphorylation of smooth muscle ROCK was blocked by ET‐1‐receptor antagonists and ROCK inhibitors. Moreover, OroA post‐treatment suppressed, via inhibiting NF‐κB activation, inducible NOS expression and circulating NO. Conclusions and Implications Reversal of endotoxemic hypotensive by OroA was due to release of endothelial ET‐1, upregulated by LPS, from mesenteric arteries, inducing prompt and sustained vasoconstriction via activation of vascular smooth muscle RhoA / ROCK‐pathway. In late endotoxemia, OroA‐induced vasoconstriction was partly due to decreased circulating NO. Activation of endothelium‐dependent constriction in large resistance arteries and suppression of systemic inflammation offer new strategies for acute management of endotoxemic hypotensive shock

  13. Exercise-induced decrease in insular cortex rCBF during postexercise hypotension.

    PubMed

    Lamb, Kala; Gallagher, Kevin; McColl, Roderick; Mathews, Dana; Querry, Ross; Williamson, Jon W

    2007-04-01

    The insular cortex (IC), a region of the brain involved in blood pressure (BP) modulation, shows decreases in regional cerebral blood flow (rCBF) during postexercise hypotension (PEH). To determine whether changes in IC neural activity were caused by prior exercise or by changes in BP, this investigation compared patterns of rCBF during periods of hypotension, which was induced by prior exercise (i.e., PEH) and sodium nitroprusside (SNP) infusion and a cold pressor (CP), to restore BP. Ten subjects were studied on three different days with randomly assigned conditions: i) resting baseline; ii) PEH; and iii) SNP-induced hypotension (matched to the PEH BP decrease). Data were collected for heart rate (HR) and mean BP, and rCBF was assessed using single-photon emission computed tomography (SPECT) as an index of brain activation. Using ANOVA across conditions, there were differences (P<0.05; mean +/- SD) from baseline during PEH for HR (+12 +/- 3 bpm) and mean BP (-8 +/- 2 mm Hg) and during SNP-induced hypotension (HR = +15 +/- 4 bpm; MBP = -9 +/- 2 mm Hg), with no differences between PEH and SNP. After exercise, there were decreases (P<0.05) in the leg sensorimotor area, anterior cingulate, and the right and left inferior thalamus, right inferior insula, and left anterior insular regions. During SNP-induced hypotension, there were significant increases in the right and left inferior thalamus and the right and left inferior anterior IC. CP during PEH increased BP and IC activity. Data show that reductions in IC neural activity are not caused by acute BP decreases. Findings suggest that exercise can lead to a temporary decrease in IC neural activity, which may be a significant neural factor contributing to PEH.

  14. Neurogenic orthostatic hypotension: a double-blind, placebo-controlled study with midodrine

    NASA Technical Reports Server (NTRS)

    Jankovic, J.; Gilden, J. L.; Hiner, B. C.; Kaufmann, H.; Brown, D. C.; Coghlan, C. H.; Rubin, M.; Fouad-Tarazi, F. M.

    1993-01-01

    PURPOSE: To investigate the efficacy and safety of midodrine for treatment of patients with orthostatic hypotension due to autonomic failure. PATIENTS: Ninety-seven patients with orthostatic hypotension were randomized in a 4-week, double-blinded, placebo-controlled study with a 1-week placebo run-in period. Patients ranged in age from 22 to 86 years (mean: 61 years). METHODS: After a 1-week run-in phase, either placebo or midodrine at a dose of 2.5 mg, 5 mg, or 10 mg was administered three times a day for 4 weeks. Both the placebo group and the 2.5-mg midodrine group received constant doses throughout the double-blind phase. The patients receiving 5 mg or 10 mg of midodrine were given doses that were increased at weekly intervals by 2.5-mg increments until the designated dose was reached. Efficacy evaluations were based on an improvement at 1-hour postdose in standing systolic blood pressure and in symptoms of orthostatic hypotension (syncope, dizziness/lightheadedness, weakness/fatigue, and low energy level). RESULTS: Midodrine (10 mg) increased standing systolic blood pressure by 22 mm Hg (28%, p < 0.001 versus placebo). Midodrine improved (p < 0.05) the following symptoms of orthostatic hypotension compared to placebo: dizziness/lightheadedness, weakness/fatigue, syncope, low energy level, impaired ability to stand, and feelings of depression. The overall side effects were mainly mild to moderate. One or more side effects were reported by 22% of the placebo group compared with 27% of the midodrine-treated group. Scalp pruritus/tingling, which was reported by 10 of 74 (13.5%) of the midodrine-treated patients, was most frequent. Other reported side effects included supine hypertension (8%) and feelings of urinary urgency (4%). CONCLUSION: We conclude that midodrine is an effective and well-tolerated treatment for moderate-to-severe orthostatic hypotension associated with autonomic failure.

  15. Hypoglycaemic and hypotensive effects of Globimetula cupulata (DC) Van Tieghem (Loranthaceae) aqueous leaf extract in rats.

    PubMed

    Ojewole, J A O; Adewole, S O

    2007-01-01

    The leaves of some mistletoes, specifically Loranthus micranthus Linn, Tapinanthus dodoneifolius (DC) Danser and Globimetula cupulata (DC) Van Tieghem (family: Loranthaceae), are used traditionally in Nigerian folk medicine to manage, control and/or treat a plethora of human ailments, including diabetes mellitus and hypertension. In order to scientifically appraise some of the folkloric, ethnomedical uses of Globimetula species, the present study was undertaken to investigate the hypoglycaemic and hypotensive effects of Globimetula cupulata aqueous leaf extract (GCE, 50-800 mg/kg po) in rat experimental paradigms. The hypoglycaemic effect of the plant extract was examined in normal (normoglycaemic) and diabetic (hyperglycaemic) rats using a streptozotocin (STZ)-induced diabetes model. Normotensive Wistar and hypertensive Dahl salt-sensitive rats were used to investigate the hypotensive (antihypertensive) effect of the plant extract. Metformin (MFM, 500 mg/kg po) was used as the reference hypoglycaemic agent for comparison. Acute oral administrations of G cupulata aqueous leaf extract (GCE, 50-800 mg/kg po) caused dose-related, significant (p < 0.05-0.001) hypoglycaemia in normal and STZ-treated diabetic rats. Furthermore, acute intravenous administrations of GCE (50-800 mg/kg iv) produced dose-dependent, significant reductions (p < 0.05-0.001) in systemic arterial blood pressure and heart rates of the normotensive and hypertensive rats used. Although the exact hypoglycaemic and hypotensive mechanisms of action of the plant extract still remain speculative, it is unlikely that the extract induced hypotension in the mammalian experimental animal model via cholinergic mechanisms, since its cardiovascular effects were resistant to atropine pretreatment. However, the findings of this experimental study indicated that Globimetula cupulata aqueous leaf extract possesses hypoglycaemic and hypotensive properties. This therefore lends pharmacological support to the folkloric

  16. MRI reveals edema in larynx (but not in brain) during anaphylactic hypotension in anesthetized rats.

    PubMed

    Toyota, Ichiro; Tanida, Mamoru; Shibamoto, Toshishige; Wang, Mofei; Kurata, Yasutaka; Tonami, Hisao

    2013-11-01

    Anaphylactic shock is sometimes accompanied by local interstitial edema due to increased vascular permeability. We performed magnetic resonance imaging (MRI) to compare edema in the larynx and brain of anesthetized rats during anaphylactic hypotension versus vasodilator-induced hypotension. Male Sprague Dawley rats were subjected to hypotension induced by the ovalbumin antigen (n=7) or a vasodilator sodium nitroprusside (SNP; n=7). Apparent diffusion coefficient (ADC) and T2-relaxation time (T2RT) were quantified on MRI performed repeatedly for up to 68 min after the injection of either agent. The presence of laryngeal edema was also examined by histological examination. Separately, the occurrence of brain edema was assessed by measuring brain water content using the wet/dry method in rats with anaphylaxis (n=5) or SNP (n=5) and the non-hypotensive control rats (n=5). Mast cells in hypothalamus were morphologically examined. Mean arterial blood pressure similarly decreased to 35 mmHg after an injection of the antigen or SNP. Hyperintensity on T2-weighted images (as reflected by elevated T2RT) was found in the larynx as early as 13 min after an injection of the antigen, but not SNP. A postmortem histological examination revealed epiglottic edema in the rats with anaphylaxis, but not SNP. In contrast, no significant changes in T2RT or ADC were detectable in the brains of any rats studied. In separate experiments, the quantified brain water content did not increase in either anaphylaxis or SNP rats, as compared with the non-hypotensive control rats. The numbers of mast cells with metachromatic granules in the hypothalamus were not different between rats with anaphylaxis and SNP, suggesting the absence of anaphylactic reaction in hypothalamus. Edema was detected using the MRI technique in the larynx during rat anaphylaxis, but not in the brain.

  17. Associations of endothelial dysfunction and arterial stiffness with intradialytic hypotension and hypertension

    PubMed Central

    DUBIN, Ruth; OWENS, Christopher; GASPER, Warren; GANZ, Peter; JOHANSEN, Kirsten

    2011-01-01

    Intradialytic hypotension and hypertension are both independently associated with mortality among persons with end-stage renal disease on hemodialysis. Endothelial dysfunction and arterial stiffness are two possible mechanisms underlying these phenomena, but their association with hemodynamic instability during dialysis has not been evaluated. Thirty patients were recruited from chronic dialysis units at San Francisco General Hospital and San Francisco Veterans Affairs Medical Center. Endothelial dysfunction was assessed with flow-mediated dilation of the brachial artery after upper arm occlusion. Arterial stiffness was assessed using carotid-femoral pulse wave velocity measured by tonometry. Intradialytic hypotension and hypertension were defined as the average decrease in systolic blood pressure (SBP) over 1 week, as well as the frequency over 1 month of hypotension or hypertension. Every 5% decrease in flow-mediated dilation was associated with a 7.5mmHg decrease in SBP after adjustment for phosphorus, body mass index, atherosclerosis, and ultrafiltration (P=0.02). Every 5 m/s increase in pulse wave velocity was associated with an 8mmHg increase in SBP after adjustment for predialysis SBP and ultrafiltration (P=0.03). Over 1 month, every 5% lower flow-mediated dilation was associated with a 10% higher frequency of hypotension (P=0.09), and every 5 m/s increase in pulse wave velocity was associated with an 15% higher frequency of hypertension (P=0.02). In a cross-sectional analysis of 30 dialysis patients, endothelial dysfunction and arterial stiffness were independently associated with intradialytic hypotension and intradialytic hypertension, respectively. Elucidating these potential mechanisms of hemodynamic instability during dialysis may facilitate development of treatment strategies specific to this pathophysiology. PMID:21658174

  18. Opportunities for Web-based Drug Repositioning: Searching for Potential Antihypertensive Agents with Hypotension Adverse Events

    PubMed Central

    Wang, Kejian; Wan, Mei; Wang, Rui-Sheng

    2016-01-01

    Background Drug repositioning refers to the process of developing new indications for existing drugs. As a phenotypic indicator of drug response in humans, clinical side effects may provide straightforward signals and unique opportunities for drug repositioning. Objective We aimed to identify drugs frequently associated with hypotension adverse reactions (ie, the opposite condition of hypertension), which could be potential candidates as antihypertensive agents. Methods We systematically searched the electronic records of the US Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) through the openFDA platform to assess the association between hypotension incidence and antihypertensive therapeutic effect regarding a list of 683 drugs. Results Statistical analysis of FAERS data demonstrated that those drugs frequently co-occurring with hypotension events were more likely to have antihypertensive activity. Ranked by the statistical significance of frequent hypotension reporting, the well-known antihypertensive drugs were effectively distinguished from others (with an area under the receiver operating characteristic curve > 0.80 and a normalized discounted cumulative gain of 0.77). In addition, we found a series of antihypertensive agents (particularly drugs originally developed for treating nervous system diseases) among the drugs with top significant reporting, suggesting the good potential of Web-based and data-driven drug repositioning. Conclusions We found several candidate agents among the hypotension-related drugs on our list that may be redirected for lowering blood pressure. More important, we showed that a pharmacovigilance system could alternatively be used to identify antihypertensive agents and sustainably create opportunities for drug repositioning. PMID:27036325

  19. Better marking means cheaper pruning.

    Treesearch

    Kenneth R. Eversole

    1953-01-01

    Careful selection of trees to be pruned can make the difference between profit and loss on the pruning investment, especially in stands where no thinning is contemplated. Expert marking is required to make sure that the pruned trees will grow rapidly. The most important variable influencing the cost of clear wood produced by pruning is growth rate. For example, at 3...

  20. Early-Modern "Speech" Marks

    ERIC Educational Resources Information Center

    Blackburn, Nick

    2011-01-01

    This essay presents a revised history of the punctuation mark ["], drawn from the earliest communities who made it their own. By situating the development of ["] in its historical context, from first uses of the diple [diple] by the Greek scholar Aristarchus, it explains how it was the general applications which persisted into the sixteenth…

  1. Reference Point Marking in Emai.

    ERIC Educational Resources Information Center

    Schaefer, Ronald P.

    Semantic noun classes in Emai, an Edoid language of Nigeria, are examined with respect to a process of Reference Point Marking (RPM) in order to explore the relationship between discourse and lexical semantics. Across pre- and post-verbal positions subcategorized by verbs like "rere" ("to be far"), these classes are shown to…

  2. Early-Modern "Speech" Marks

    ERIC Educational Resources Information Center

    Blackburn, Nick

    2011-01-01

    This essay presents a revised history of the punctuation mark ["], drawn from the earliest communities who made it their own. By situating the development of ["] in its historical context, from first uses of the diple [diple] by the Greek scholar Aristarchus, it explains how it was the general applications which persisted into the sixteenth…

  3. EP Profiles Inventor Mark Sherron

    ERIC Educational Resources Information Center

    Williams, John M.

    2006-01-01

    This article profiles Mark Jerome Sherron, inventor of the ALLIES Line of electronic sensors for blind and visually-impaired people. Featuring the American Liquid Level Indicator electronic sensor (ALLI), Sherron's ALLIES product line also includes the Light Intensity Level Indicator (LILI), a multi-function electronic light sensor for electronic…

  4. Keynote Address: Rev. Mark Massa

    ERIC Educational Resources Information Center

    Massa, Mark S.

    2011-01-01

    Rev. Mark S. Massa, S.J., is the dean and professor of Church history at the School of Theology and Ministry at Boston College. He was invited to give a keynote to begin the third Catholic Higher Education Collaborative Conference (CHEC), cosponsored by Boston College and Fordham University. Fr. Massa's address posed critical questions about…

  5. Spear-Marked Black Moth

    Treesearch

    Richard A. Werner; Bruce H. Baker

    1977-01-01

    The spear-marked black moth, Rheumaptera hastata (L.) (Lepidoptera: Geometridae) is a serious defoliator of paper birch (Betula papyrifera Marsh.) in interior Alaska. Epidemic populations have occurred at 15- to 17- year intervals, persisted for 2 years, and then collapsed. Recorded outbreaks occurred in 1941, acreage unknown; from 1957 to 1958, 5 million acres (2...

  6. EP Profiles Inventor Mark Sherron

    ERIC Educational Resources Information Center

    Williams, John M.

    2006-01-01

    This article profiles Mark Jerome Sherron, inventor of the ALLIES Line of electronic sensors for blind and visually-impaired people. Featuring the American Liquid Level Indicator electronic sensor (ALLI), Sherron's ALLIES product line also includes the Light Intensity Level Indicator (LILI), a multi-function electronic light sensor for electronic…

  7. The organizational structure of an intensive care unit influences treatment of hypotension among critically ill patients: A retrospective cohort study.

    PubMed

    Boone, M Dustin; Massa, Jennifer; Mueller, Ariel; Jinadasa, Sayuri P; Lee, Joon; Kothari, Rishi; Scott, Daniel J; Callahan, Julie; Celi, Leo Anthony; Hacker, Michele R

    2016-06-01

    Prior studies report that weekend admission to an intensive care unit is associated with increased mortality, potentially attributed to the organizational structure of the unit. This study aims to determine whether treatment of hypotension, a risk factor for mortality, differs according to level of staffing. Using the Multiparameter Intelligent Monitoring in Intensive Care database, we conducted a retrospective study of patients admitted to an intensive care unit at Beth Israel Deaconess Medical Center who experienced one or more episodes of hypotension. Episodes were categorized according to the staffing level, defined as high during weekday daytime (7 am-7 pm) and low during weekends or nighttime (7 pm-7 am). Patients with a hypotensive event on a weekend were less likely to be treated compared with those that occurred during the weekday daytime (P = .02). No association between weekday daytime vs weekday nighttime staffing levels and treatment of hypotension was found (risk ratio, 1.02; 95% confidence interval, 0.98-1.07). Patients with a hypotensive event on a weekend were less likely to be treated than patients with an event during high-staffing periods. No association between weekday nighttime staffing and hypotension treatment was observed. We conclude that treatment of a hypotensive episode relies on more than solely staffing levels. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. The organizational structure of an intensive care unit influences treatment of hypotension among critically ill patients: A retrospective cohort study

    PubMed Central

    Boone, M. Dustin; Massa, Jennifer; Mueller, Ariel; Jinadasa, Sayuri P; Lee, Joon; Kothari, Rishi; Scott, Daniel J.; Callahan, Julie; Celi, Leo Anthony; Hacker, Michele R.

    2016-01-01

    Purpose Prior studies report that weekend admission to an intensive care unit is associated with increased mortality, potentially attributed to the organizational structure of the unit. This study aims to determine whether treatment of hypotension, a risk factor for mortality, differs according to level of staffing. Methods Using the Multiparameter Intelligent Monitoring in Intensive Care database, we conducted a retrospective study of patients admitted to an intensive care unit at Beth Israel Deaconess Medical Center who experienced one or more episodes of hypotension. Episode(s) were categorized according to the staffing level, defined as high during weekday daytime (7am–7pm) and low during weekends or nighttime (7pm–7am). Results Patients with a hypotensive event on a weekend were less likely to be treated compared to those that occurred during the weekday daytime (p=0.02). No association between weekday daytime versus weekday nighttime staffing levels and treatment of hypotension was found (RR 1.02; 95% CI 0.98–1.07). Conclusion Patients with a hypotensive event on a weekend were less likely to be treated than patients with an event during high-staffing periods. No association between weekday nighttime staffing and hypotension treatment was observed. We conclude that treatment of a hypotensive episode relies on more than solely staffing levels. PMID:26975737

  9. Hypotension is a risk factor for new pressure ulcer occurrence in older patients after admission to an acute hospital.

    PubMed

    Man, Shiu-piu; Au-Yeung, Tung-wai

    2013-08-01

    Pressure ulcer occurrence in older patients admitted to hospital has not been studied thoroughly; yet, pressure ulcers frequently develop among the frail older patients who are hospitalized. Identifying risk factors for pressure ulcer occurrence is of utmost importance in preventing its development in this group of patients. Hypoperfusion, as manifested by hypotension, is theoretically important in the development of pressure ulcer. However, studies on this aspect are scarce. To examine whether a hypotensive episode (systolic blood pressure less than or equal to 90 mm Hg) is associated with pressure ulcer occurrence. This was a retrospective cohort study in a regional hospital. It recruited 259 patients aged 65 or older who were admitted to a convalescence ward and had a hospital stay for more than 5 days. Baseline clinical characteristics and the possible risk factors of pressure ulcer occurrence on admission and any episode of hypotension were recorded. The primary outcome measured was the incidence of pressure ulcer occurrence in the index admission. Hypotension was strongly associated with incident pressure ulcer occurrence (odds ratio 6.71, P = .001). Hypotension was an important risk factor for incident pressure ulcer occurrence during hospital stay. Every effort has to be taken to try to prevent hypotension. Precautions to prevent pressure ulcer development should be taken on patients who are hypotensive. Copyright © 2013 American Medical Directors Association, Inc. Published by Elsevier Inc. All rights reserved.

  10. Higher incidence of hypotension episodes in women during the sub-acute phase of ST elevation myocardial infarction and relationship to covariates

    PubMed Central

    Kala, Petr; Andrsova, Irena; Benesova, Klara; Holicka, Maria; Jarkovsky, Jiri; Hnatkova, Katerina; Koc, Lumir; Mikolaskova, Monika; Novakova, Tereza; Ondrus, Tomas; Privarova, Lenka; Spinar, Jindrich; Malik, Marek

    2017-01-01

    Objective The introduction of primary percutaneous coronary intervention (PPCI) has modified the profile of ST elevation myocardial infarction (STEMI) patients. Occurrence and prognostic significance of hypotension episodes are not known in PPCI treated STEMI patients. It is also not known whether and/or how the hypotension episodes correlate with the degree of myocardial damage and whether there are any sex differences. Methods Data of 293 consecutive STEMI patients (189 males) treated by PPCI and without cardiogenic shock were analyzed. Blood pressure was measured noninvasively. A hypotensive episode was defined as a systolic blood pressure below 90 mmHg over a period of at least 30 minutes. Results A hypotensive episode was observed in 92 patients (31.4%). Female sex was the strongest independent predictor of hypotension episodes (p < 0.0001), while there was no relationship to electrocardiographic STEMI localization. Hypotensive patients had significantly higher levels of troponin T and brain natriuretic peptide; hypotensive episodes were particularly frequent in women with increased troponin T. Treatment with angiotensin-converting enzyme inhibitor (ACEI), angiotensin receptor blocker (ARB) and betablockers was less frequent in hypotensive patients. After a mean 20-month follow-up, all-cause mortality did not differ between hypotensive patients and others. However, mortality in hypotensive patients who did not tolerate ACEI/ARB therapy was significantly higher compared to other hypotensive patients (p = 0.016). Conclusion Hypotension episodes are not uncommon in the sub-acute phase of contemporarily treated STEMI patients with a striking difference between sexes—female sex was the strongest independent predictor of hypotension episodes. Hypotensive episodes may lead to a delay in pharmacotherapy which influences prognosis. Higher incidence of hypotension in women could at least partially explain the sex-related differences in the use of cardiovascular

  11. Effect of discontinuation of antihypertensive medication on orthostatic hypotension in older persons with mild cognitive impairment: the DANTE Study Leiden.

    PubMed

    Moonen, Justine E F; Foster-Dingley, Jessica C; de Ruijter, Wouter; van der Grond, Jeroen; de Craen, Anton J M; van der Mast, Roos C

    2016-03-01

    the relationship between antihypertensive medication and orthostatic hypotension in older persons remains ambiguous, due to conflicting observational evidence and lack of data of clinical trials. to assess the effect of discontinuation of antihypertensive medication on orthostatic hypotension in older persons with mild cognitive impairment. a total of 162 participants with orthostatic hypotension were selected from the Discontinuation of Antihypertensive Treatment in Elderly people (DANTE) Study. This randomised clinical trial included community-dwelling participants aged ≥75 years, with mild cognitive impairment, using antihypertensive medication and without serious cardiovascular disease. Participants were randomised to discontinuation or continuation of antihypertensive treatment (ratio 1:1). Orthostatic hypotension was defined as a drop of at least 20 mmHg in systolic blood pressure and/or 10 mmHg in diastolic blood pressure on standing from a seated position. Outcome was the absence of orthostatic hypotension at 4-month follow-up. Relative risks (RR) were calculated by intention-to-treat and per-protocol analyses. at follow-up, according to intention-to-treat analyses, of the 86 persons assigned to discontinuation of antihypertensive medication, 43 (50%) were free from orthostatic hypotension, compared with 29 (38%) of the 76 persons assigned to continuation of medication [RR 1.31 (95% confidence interval (CI) 0.92-1.87); P = 0.13]. Per-protocol analysis showed that recovery from orthostatic hypotension was significantly higher in persons who completely discontinued all antihypertensive medication (61%) compared with the continuation group (38%) [RR 1.60 (95% CI 1.10-2.31); P = 0.01]. in older persons with mild cognitive impairment and orthostatic hypotension receiving antihypertensive medication, discontinuation of antihypertensive medication may increase the probability of recovery from orthostatic hypotension. © The Author 2016. Published by Oxford

  12. 15 CFR 272.3 - Approved markings.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... STANDARDS AND TECHNOLOGY, DEPARTMENT OF COMMERCE MAKING OF TOY, LOOK-ALIKE, AND IMITATION FIREARMS MARKING OF TOY, LOOK-ALIKE AND IMITATION FIREARMS § 272.3 Approved markings. The following markings are...

  13. Effects of Sacubitril/Valsartan (LCZ696) on Natriuresis, Diuresis, Blood Pressures, and NT-proBNP in Salt-Sensitive Hypertension.

    PubMed

    Wang, Tzung-Dau; Tan, Ru-San; Lee, Hae-Young; Ihm, Sang-Hyun; Rhee, Moo-Yong; Tomlinson, Brian; Pal, Parasar; Yang, Fan; Hirschhorn, Elizabeth; Prescott, Margaret F; Hinder, Markus; Langenickel, Thomas H

    2017-01-01

    Salt-sensitive hypertension (SSH) is characterized by impaired sodium excretion and subnormal vasodilatory response to salt loading. Sacubitril/valsartan (LCZ696) was hypothesized to increase natriuresis and diuresis and result in superior blood pressure control compared with valsartan in Asian patients with SSH. In this randomized, double-blind, crossover study, 72 patients with SSH received sacubitril/valsartan 400 mg and valsartan 320 mg once daily for 4 weeks each. SSH was diagnosed if the mean arterial pressure increased by ≥10% when patients switched from low (50 mmol/d) to high (320 mmol/d) sodium diet. The primary outcome was cumulative 6- and 24-hour sodium excretion after first dose administration. Compared with valsartan, sacubitril/valsartan was associated with a significant increase in natriuresis (adjusted treatment difference: 24.5 mmol/6 hours, 50.3 mmol/24 hours, both P<0.001) and diuresis (adjusted treatment difference: 291.2 mL/6 hours, P<0.001; 356.4 mL/24 hours, P=0.002) on day 1, but not on day 28, and greater reductions in office and ambulatory blood pressure on day 28. Despite morning dosing of both drugs, ambulatory blood pressure reductions were more pronounced at nighttime than at daytime or the 24-hour average. Compared with valsartan, sacubitril/valsartan significantly reduced N-terminal pro B-type natriuretic peptide levels on day 28 (adjusted treatment difference: -20%; P=0.001). Sacubitril/valsartan and valsartan were safe and well tolerated with no significant changes in body weight or serum sodium and potassium levels with either treatments. In conclusion, sacubitril/valsartan compared with valsartan was associated with short-term increases in natriuresis and diuresis, superior office and ambulatory blood pressure control, and significantly reduced N-terminal pro B-type natriuretic peptide levels in Asian patients with SSH. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01681576. © 2016 American Heart Association, Inc.

  14. Laser marking of component parts

    SciTech Connect

    Gress, A.V. Jr.

    1983-01-01

    Permanent identification of components and subassemblies for traceability and historical purposes is essential for assemblies subject to long term storage. Marketing requirements run the gamut from simple functional alphanumerics for terminal or wire numbers to complex component identification involving program nomenclature, part number, manufacturer's code, serial number, data code, and lot or batch number. The wide range of opaque materials marked includes both ferrous and nonferrous materials, plastics, composites, and ceramics.

  15. Optimal diagnostic thresholds for diagnosis of orthostatic hypotension with a 'sit-to-stand test'.

    PubMed

    Shaw, Brett H; Garland, Emily M; Black, Bonnie K; Paranjape, Sachin Y; Shibao, Cyndya A; Okamoto, Luis E; Gamboa, Alfredo; Diedrich, André; Plummer, W Dale; Dupont, William D; Biaggioni, Italo; Robertson, David; Raj, Satish R

    2017-05-01

    This study aimed to identify optimal blood pressure cut-offs to diagnose orthostatic hypotension during a sit-to-stand manoeuvre. This was a cross-sectional study of patients and healthy controls from the Vanderbilt Autonomic Dysfunction Center. Blood pressure was measured while supine, seated and standing. Blood pressure changes were calculated from supine-to-standing and seated-to-standing. Orthostatic hypotension was diagnosed on the basis of a supine-to-standing SBP drop at least 20 mmHg or a DBP drop at least 10 mmHg. Receiver operator characteristic (ROC) curves identified optimal sit-to-stand cut-offs. Amongst the 831 individuals, more had systolic orthostatic hypotension [n = 354 (43%)] than diastolic orthostatic hypotension [n = 305 (37%)] during lying-to-standing. The ROC curves had good characteristics [SBP area under curve = 0.916 (95% confidence interval: 0.896-0.936), P < 0.001; DBP area under curve = 0.930 (95% confidence interval: 0.909-0.950), P < 0.001]. A sit-to stand SBP drop at least 15 mmHg had optimal test characteristics (sensitivity = 80.2%; specificity = 88.9%; positive predictive value = 84.2%; negative predictive value = 85.8%), as did a DBP drop at least 7 mmHg (sensitivity = 87.2%; specificity = 87.2%; positive predictive value = 80.1%; negative predictive value = 92.0%). A sit-to-stand manoeuvre with lower diagnostic cut-offs for orthostatic hypotension provides a simple screening test for orthostatic hypotension in situations wherein a supine-to-standing manoeuvre cannot be easily performed. Our analysis suggests that a SBP drop at least 15 mmHg or a DBP drop at least 7 mmHg best optimizes sensitivity and specificity of this sit-to-stand test.

  16. Association and moderation of self-reported hypotension with traffic noise exposure: a neglected relationship.

    PubMed

    Lercher, Peter; Widmann, Ulrich

    2013-01-01

    In a short-term experimental study about one-third of subjects exposed to noise shows both increases and decreases in blood pressure. While the association of noise with hypertension is established it is not yet known whether hypotension is associated with noise in field studies. In a cross-sectional study the association of self-reported hypotension and low blood pressure readings with traffic noise was examined in adults (age 25-65, N = 1989, participation = 62%). Noise exposure was based on both, short and long-term day/night recordings and standard noise mapping. Questionnaire data on socio-demographics, housing, life-style, noise and weather sensitivity, health status, mental and physical symptoms were available to adjust for potential confounding and testing for moderation. Non-linear multiple regression was applied to estimate the association between the two outcomes and overall noise exposure. We did not observe a stable relation between noise and low blood pressure readings since the number of subjects based on the recommended cut-off points (5 th percentile or 110 (100)/60 mmHg) was too small. However, self-reported hypotension was non-linearly associated with noise exposure ( P = 0.044) in the presence of a strong sex × age effect modification ( P < 0.0001). Another significant moderation by noise were observed with reported symptoms of exhaustion ( P = 0.03). Weather sensitivity showed a significant interaction with noise sensitivity ( P = 0.02) and also a non-linear interaction with age ( P = 0.02). The results remained stable after adjustment for variables known to be associated with constitutional hypotension. The exposure-effect curve ascends around sound levels of 55 dBA. The results suggest a novel moderated association of noise with self-reported hypotension, predominantly in weather sensitive women with symptoms of exhaustion. Further and larger studies are needed to replicate the potential moderating effect of noise on persons with

  17. Effective plasma volume in cirrhosis with ascites. Evidence that a decreased value does not account for renal sodium retention, a spontaneous reduction in glomerular filtration rate (GFR), and a fall in GFR during drug-induced diuresis

    PubMed Central

    Lieberman, Fred L.; Ito, Sosuke; Reynolds, Telfer B.

    1969-01-01

    A reduction in effective (nonportal) plasma volume is considered the basis for renal sodium retention, a spontaneous reduction in glomerular filtration rate (GFR), and a fall in GFR occurring during drug-induced diuresis in patients with cirrhosis and ascites. In the present study the concept of a reduced effective plasma volume in cirrhosis is challenged by two lines of evidence, even though effective plasma volume itself could not be measured. (a) Total plasma volume failed to rise in 10 patients with the spontaneous loss of ascites, the appearance of sodium in the urine, and a rise in GFR. Portal pressure remained constant in these patients as ascites left, suggesting that effective plasma volume had not increased while portal plasma volume decreased. (b) Reduction of GFR could not be prevented in five patients with cirrhosis and ascites while total plasma volume was prevented from falling with albumin infusions during drug-induced diuresis. Reduction of GFR during drug-induced diuresis in 15 patients with cirrhosis and ascites was completely reversed with saline infusion despite continued diuresis with the identical drugs, excluding drug nephrotoxicity as the cause for the reduced GFR. The ascites of cirrhosis might no longer be regarded as a cause of effective plasma volume contraction, stimulating renal sodium retention and a reduction in GFR. More likely, this form of ascites is a result of plasma volume expansion and sodium retention. The causes for renal sodium retention and a spontaneous reduction in GFR remain unknown. The cause for a fall in GFR during drug-induced diuresis also remains unknown, but effective plasma volume contraction and drug nephrotoxicity seem excluded. Images PMID:5771197

  18. Marked Initial Pitch in Questions Signals Marked Communicative Function.

    PubMed

    Sicoli, Mark A; Stivers, Tanya; Enfield, N J; Levinson, Stephen C

    2015-06-01

    In conversation, the initial pitch of an utterance can provide an early phonetic cue of the communicative function, the speech act, or the social action being implemented. We conducted quantitative acoustic measurements and statistical analyses of pitch in over 10,000 utterances, including 2512 questions, their responses, and about 5000 other utterances by 180 total speakers from a corpus of 70 natural conversations in 10 languages. We measured pitch at first prominence in a speaker's utterance and discriminated utterances by language, speaker, gender, question form, and what social action is achieved by the speaker's turn. Through applying multivariate logistic regression we found that initial pitch that significantly deviated from the speaker's median pitch level was predictive of the social action of the question. In questions designed to solicit agreement with an evaluation rather than information, pitch was divergent from a speaker's median predictably in the top 10% of a speakers range. This latter finding reveals a kind of iconicity in the relationship between prosody and social action in which a marked pitch correlates with a marked social action. Thus, we argue that speakers rely on pitch to provide an early signal for recipients that the question is not to be interpreted through its literal semantics but rather through an inference.

  19. Severe hypernatremia from a urea-induced diuresis due to body protein wasting in an insulin-resistant type 2 diabetic patient.

    PubMed

    Anderson, Amy; Barrett, Eugene J

    2013-05-01

    Hypernatremia is encountered after pituitary or hypothalamic surgery and typically is secondary to vasopressin deficiency resulting in increased free water clearance with inadequate water replacement. We report a type 2 diabetic patient with severe hypernatremia (Na⁺ = 161 mEq/L) after hypothalamic surgery. Unexpectedly, this was accompanied by persistent urinary hypertonicity and negative total but positive electrolyte free water clearance. Measurement of urinary electrolytes and urea revealed that an osmotic diuresis induced by urea derived principally by breakdown of endogenous protein was causative. Body protein losses over 48 hours were estimated to exceed 2 kg of lean mass. High-dose glucocorticoid, insulin resistance, and a postsurgical catabolic stress likely contributed. In surgically severely stressed individuals, proteolysis of endogenous protein can strongly impact body water metabolism and contribute to severe hypernatremia.

  20. Severe Hypernatremia From a Urea-Induced Diuresis due to Body Protein Wasting in an Insulin-Resistant Type 2 Diabetic Patient

    PubMed Central

    Anderson, Amy

    2013-01-01

    Context: Hypernatremia is encountered after pituitary or hypothalamic surgery and typically is secondary to vasopressin deficiency resulting in increased free water clearance with inadequate water replacement. Objective: We report a type 2 diabetic patient with severe hypernatremia (Na+ = 161 mEq/L) after hypothalamic surgery. Unexpectedly, this was accompanied by persistent urinary hypertonicity and negative total but positive electrolyte free water clearance. Main Outcome Measure: Measurement of urinary electrolytes and urea revealed that an osmotic diuresis induced by urea derived principally by breakdown of endogenous protein was causative. Body protein losses over 48 hours were estimated to exceed 2 kg of lean mass. High-dose glucocorticoid, insulin resistance, and a postsurgical catabolic stress likely contributed. Conclusion: In surgically severely stressed individuals, proteolysis of endogenous protein can strongly impact body water metabolism and contribute to severe hypernatremia. PMID:23493436

  1. Refractory hypotension due to Rogaine® (minoxidil) ingestion managed with midodrine.

    PubMed

    Garrard, Alexander; Wood, Adam; Sollee, Dawn; Aaronson, Patrick

    2011-12-01

    Minoxidil (Rogaine®) is a direct vasodilator that can cause significant toxicity when ingested. We report a case of ingestion of topical minoxidil [Rogaine® (Johnson & Johnson Healthcare Products, Division of McNeil-PPC, Inc)] resulting in refractory hypotension that was successfully managed with the oral α (1) agonist midodrine. A 48-year-old male who ingested an eight ounce bottle of Rogaine® presented to the emergency department. The patient presented with a blood pressure of 57/45 mmHg and a pulse of 84 beats per minute. The patient received IV fluids and multiple vasopressors to maintain an adequate mean arterial pressure. Midodrine, an oral α (1) vasopressor, was added 10 hours post ingestion and was able to maintain an adequate mean arterial pressure. Over the next two days, midodrine was titrated down as his blood pressure returned to baseline. Midodrine may serve as an additional option to treat toxicant induced hypotension.

  2. An Unusual Case of Post-Traumatic Headache Complicated by Intracranial Hypotension

    PubMed Central

    Siavoshi, Sara; Dougherty, Carrie; Ailani, Jessica; Yadwadkar, Kaustubh; Berkowitz, Frank

    2016-01-01

    We present a case of post-traumatic headache complicated by intracranial hypotension resulting in an acquired Chiari malformation and myelopathy with syringomyelia. This constellation of findings suggest a possible series of events that started with a traumatic cerebral spinal fluid (CSF) leak, followed by descent of the cerebellar tonsils and disruption of CSF circulation that caused spinal cord swelling and syrinx. This unusual presentation of post-traumatic headache highlights the varying presentations and the potential sequelae of intracranial hypotension. In addition, the delayed onset of upper motor neuron symptoms along with initially normal head computerized tomography scan (CT) findings, beg the question of whether or not a post-traumatic headache warrants earlier magnetic resonance imaging (MRI). PMID:28036062

  3. Antioxidant and Vasodilator Activity of Ugni molinae Turcz. (Murtilla) and Its Modulatory Mechanism in Hypotensive Response

    PubMed Central

    Jofré, Ignacio; Pezoa, Cesar; Scheuermann, Erick; Rosalen, Pedro Luiz; Romero, Fernando

    2016-01-01

    Hypertension is a systemic condition with high morbidity and mortality rates worldwide, which poses an increased risk for cardiovascular diseases. In this study, we demonstrated the antioxidant and vasodilator activity of Ugni molinae Turcz. (Murtilla) fruit, a berry native to Chile and proposed models to explain its modulatory mechanism in hypotensive response. Murtilla fruits were cultivated in a germplasm bank and submitted to chemical and biological analyses. The phenolic compounds gallic acid, Catechin, Quercetin-3-β-D-glucoside, Myricetin, Quercetin, and Kaempferol were identified. Murtilla extract did not generate toxic effects on human endothelial cells and had significant antioxidant activity against ROS production, lipid peroxidation, and superoxide anion production. Furthermore, it showed dose-dependent vasodilator activity in aortic rings in the presence of endothelium, whose hypotensive mechanism is partially mediated by nitric oxide synthase/guanylate cyclase and large-conductance calcium-dependent potassium channels. Murtilla fruits might potentially have beneficial effects on the management of cardiovascular diseases. PMID:27688827

  4. Association between vasovagal hypotension and low sympathetic neural activity during presyncope

    NASA Technical Reports Server (NTRS)

    Cooke, William H.; Convertino, Victor A.

    2002-01-01

    Recent studies suggest that an underlying mechanism for susceptibility of patients and astronauts to presyncope includes hypoadrenergic responses to orthostatic stress. However, data used to reach this conclusion are open to various interpretations. In this report, maintenance of sympathetic neural activity (MSNA; peroneal nerve microneurography) during -60 mmHg lower body negative pressure (LBNP) was associated with maintenance of orthostatic tolerance, and disappearance of MSNA was associated with hypotension and pre-syncope. However, MSNA was substantially higher during progressive increases of negative pressure in the presyncopal subject, compared to the non-presyncopal subjects. The data from this case report question the notion that orthostatic hypotension occurs due to inadequate sympathetic neural activation during orthostatic stress in apparently normal, healthy subjects.

  5. Hypotensive effect of the hydroalcoholic extract from Jacaranda mimosaefolia leaves in rats.

    PubMed

    Nicasio, Pilar; Meckes, Mariana

    2005-02-28

    Hypothermic and cardiovascular activities of the methanol extract of Jacaranda mimosaefolia leaves were tested. To evaluate the hypotensive properties, anesthetized rats were used and temperature, blood pressure, and cardiac frequency were recorded. In addition, the in vitro effect produced by the extract on induced contraction with norepinephrine (NE) in rat aorta rings was evaluated. The extract produced a significant hypothermic effect with a maximum at 2 h, an effect which was accompanied by hypotension and low cardiac frequency, physiological conditions that were again re-established to the following 2 h. In isolated aorta preparations norepinephrine antagonistic effect was not correlated with the presence of Ca2+, pD2 for NE was modified by the extract, an effect that could explain a blockade of the adrenergic receptors.

  6. Hypoactive-hypoalert behaviour and thalamic hypometabolism due to intracranial hypotension.

    PubMed

    Kearney, Seamus; Flynn, Peter; Hughes, Simon; Spence, Wendy; McCarron, Mark Owen

    2017-08-01

    A 47-year-old man presented with a 9-year history of a hypoalert hypoactive behaviour syndrome, caused by the deep brain swelling variant of spontaneous intracranial hypotension. Along with apathy with retained cognition, he had stable ataxia, impaired upgaze and episodes of central apnoea. MRI brain showed a sagging brainstem, pointed ventricles and reduced angle between the vein of Galen and the straight sinus, but no meningeal enhancement or subdural collections. A dopamine transporter scan showed preganglionic dopamine receptor deficiency; a fluorodeoxy glucose positron emission tomography scan showed bilateral hypothalamic hypometabolism. This variant of spontaneous intracranial hypotension may alter deep brain functioning within the basal ganglia and thalamus, causing the hypoactive-hypoalert behaviour phenotype. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  7. [Characteristics of the cardiovascular system in children with primary arterial hypotension].

    PubMed

    Leont'eva, I V; Akhmetzhanova, Kh M; Belozerov, Iu M; Sipiagina, A E

    1991-01-01

    Overall 120 children aged 12 to 15 years with primary arterial hypotension and different variants of the disease course (grave, of medium gravity or mild) were examined. The control group was made up to 50 normal children. The program of the examination included electrocardiography, echocardiography, tetrapolar chest rheography and bicycle ergometry. It has been established that in children with arterial hypotension, the intracardiac hemodynamics undergoes compensatory adaptive reconstruction characterized by the enhancement of contractile and pump functions of the myocardium combined with the increased relaxation capacity. The central hemodynamics is characterized by the lowering of the general peripheral vascular resistance. The functional potentialities of the cardiovascular system decline, manifesting in the form of a decrease of exercise tolerance in association with energy losses necessary for its performance. The use of bicycle ergometry made it possible to delineate dysadaptation reactions of arterial pressure to exercise, modified by hereditary factors.

  8. Increased periocular pigmentation with ocular hypotensive lipid use in African Americans.

    PubMed

    Herndon, Leon W; Robert D Williams; Wand, Martin; Asrani, Sanjay

    2003-05-01

    To report increased eyelid pigmentation as an adverse side effect associated with topical ocular hypotensive lipids in African Americans. Interventional case series. Two African-American patients with open-angle glaucoma are described in whom increased eyelid pigmentation developed 1 month to 5 months after beginning treatment with either latanoprost or bimatoprost. Latanoprost was discontinued in an African-American patient, and pigmentation gradually diminished by 3 months after cessation of latanoprost. Increased eyelid pigmentation and increased eyelash length were noted in another African-American patient after just 4 weeks on bimatoprost. An increase in eyelid pigmentation and eyelash growth is a possible complication of topical ocular hypotensive lipid therapy, even in African-American patients. The changes seems to present earlier after bimatoprost treatment then after latanoprost treatment. Cessation of these medications may lead to loss of induced pigmentation.

  9. Head-down bed rest impairs vagal baroreflex responses and provokes orthostatic hypotension

    NASA Technical Reports Server (NTRS)

    Convertino, Victor A.; Doerr, Donald F.; Eckberg, Dwain L.; Fritsch, Janice M.; Vernikos-Danellis, Joan

    1990-01-01

    The hypothesis that baroreflex malfunction contributes to orthostatic hypotension in microgravity was tested by studying vagally mediated carotid baroreceptor-cardiac reflexes in healthy human subjects before, during, and after 30 days of 6-deg head-down bed rest. The baroreflex response relationships were provoked with ramped neck pressure-suction sequences comprising pressure elevations to 40 mm Hg followed by serial R-wave-triggered 15-mm Hg reductions to -65 mm0 Hg; each R-R interval was plotted as a function of systolic pressure minus the neck chamber pressure applied during the interval. It is shown that head-down bed rest led to an impairment of vagal baroreflex function and that it was associated with an impairment of hemodynamic adjustments to standing, indicating that baroreflex impairment may contribute to orthostatic hypotension observed in spacecrews after a flight.

  10. Hypotensive but not normotensive haemorrhage increases tryptophan hydroxylase-2 mRNA in caudal midline medulla.

    PubMed

    Brown, Heidi J; Henderson, Luke A; Keay, Kevin A

    2006-05-08

    Severe blood loss triggers shock, a precipitous hypotension and bradycardia. The integrity of (i) neurons in the vasodepressor region of the caudal midline medulla and (ii) central 5-HT neurotransmission are critical for the expression of haemorrhagic shock. This study investigated whether progressive blood loss triggers altered synthesis of 5-HT in the vasodepressor region of the caudal midline medulla by measuring changes in relative expression levels of tryptophan hydroxylase 2 (TpH 2) mRNA, the rate-limiting enzyme in the synthesis of neuronal 5-HT. Hypotensive but not normotensive haemorrhage triggered a significant increase in TpH 2 mRNA in the vasodepressor region of the caudal midline medulla, identifying an important role for 5-HT-containing caudal midline medullary neurons in haemorrhagic shock.

  11. Unexplained hypotension and exertional dyspnea in a night-cycled peritoneal dialysis patient--a rare form of icodextrin hypersensitivity.

    PubMed

    Onuigbo, Macaulay A C

    2014-01-01

    In recent years, icodextrin 7.5% has been used in PD as an alternative to glucose to achieve sustained reliable ultrafiltration (UF) and clearance without adversely increasing glucose absorption. Icodextrin is generally well tolerated. The most commonly reported adverse events are cutaneous reactions. We report a rare form of hypersensitivity to icodextrin 7.5% that was accompanied by dyspnea and symptomatic hypotension, without increased UF to account for the observed hypotension. Icodextrin produces symptomatic hypotension in up to 40% of patients by a known mechanism of increased UF and corresponding weight loss. However, it can also produce symptomatic hypotension accompanied by several other systemic symptoms in a hypersensitivity reaction. Discontinuation of the icodextrin results in prompt resolution of those symptoms. Treating nephrologists must be aware of this rare form of icodextrin hypersensitivity.

  12. Urea and NaCl regulate UT-A1 urea transporter in opposing directions via TonEBP pathway during osmotic diuresis.

    PubMed

    Kim, Yu-Mi; Kim, Wan-Young; Lee, Hyun-Wook; Kim, Jin; Kwon, H Moo; Klein, Janet D; Sands, Jeff M; Kim, Dongun

    2009-01-01

    In our previous studies of varying osmotic diuresis, UT-A1 urea transporter increased when urine and inner medullary (IM) interstitial urea concentration decreased. The purposes of this study were to examine 1) whether IM interstitial tonicity changes with different urine urea concentrations during osmotic dieresis and 2) whether the same result occurs even if the total urinary solute is decreased. Rats were fed a 4% high-salt diet (HSD) or a 5% high-urea diet (HUD) for 2 wk and compared with the control rats fed a regular diet containing 1% NaCl. The urine urea concentration decreased in HSD but increased in HUD. In the IM, UT-A1 and UT-A3 urea transporters, CLC-K1 chloride channel, and tonicity-enhanced binding protein (TonEBP) transcription factor were all increased in HSD and decreased in HUD. Next, rats were fed an 8% low-protein diet (LPD) or a 0.4% low-salt diet (LSD) to decrease the total urinary solute. Urine urea concentration significantly decreased in LPD but significantly increased in LSD. Rats fed the LPD had increased UT-A1 and UT-A3 in the IM base but decreased in the IM tip, resulting in impaired urine concentrating ability. The LSD rats had decreased UT-A1 and UT-A3 in both portions of the IM. CLC-K1 and TonEBP were unchanged by LPD or LSD. We conclude that changes in CLC-K1, UT-A1, UT-A3, and TonEBP play important roles in the renal response to osmotic diuresis in an attempt to minimize changes in plasma osmolality and maintain water homeostasis.

  13. Role in diuresis of a calcitonin receptor (GPRCAL1) expressed in a distal-proximal gradient in renal organs of the mosquito Aedes aegypti (L.).

    PubMed

    Kwon, Hyeogsun; Lu, Hsiao-Ling; Longnecker, Michael T; Pietrantonio, Patricia V

    2012-01-01

    Evolution of anthropophilic hematophagy in insects resulted in the coordination of various physiological processes for survival. In female mosquitoes, a large blood meal provides proteins for egg production and as a trade-off, rapid elimination of the excess water and solutes (Na(+), Cl(-)) is critical for maintaining homeostasis and removing excess weight to resume flight and avoid predation. This post-prandial excretion is achieved by the concerted action of multiple hormones. Diuresis and natriuresis elicited by the calcitonin-like diuretic hormone 31 (DH(31)) are believed to be mediated by a yet uncharacterized calcitonin receptor (GPRCAL) in the mosquito Malpighian tubules (MTs), the renal organs. To contribute knowledge on endocrinology of mosquito diuresis we cloned GPRCAL1 from MT cDNA. This receptor is the ortholog of the DH(31) receptor from Drosophila melanogaster that is expressed in principal cells of the fruit fly MT. Immunofluorescence similarly showed AaegGPRCAL1 is present in MT principal cells in A. aegypti, however, exhibiting an overall gradient-like pattern along the tubule novel for a GPCR in insects. Variegated, cell-specific receptor expression revealed a subpopulation of otherwise phenotypically similar principal cells. To investigate the receptor contribution to fluid elimination, RNAi was followed by urine measurement assays. In vitro, MTs from females that underwent AaegGPRcal1 knock-down exhibited up to 57% decrease in the rate of fluid secretion in response to DH(31). Live females treated with AaegGPRcal1 dsRNA exhibited 30% reduction in fluid excreted after a blood meal. The RNAi-induced phenotype demonstrates the critical contribution of this single secretin-like family B GPCR to fluid excretion in invertebrates and highlights its relevance for the blood feeding adaptation. Our results with the mosquito AaegGPRCAL1 imply that the regulatory function of calcitonin-like receptors for ion and fluid transport in renal organs arose early

  14. Urea and NaCl regulate UT-A1 urea transporter in opposing directions via TonEBP pathway during osmotic diuresis

    PubMed Central

    Kim, Yu-Mi; Kim, Wan-Young; Lee, Hyun-Wook; Kim, Jin; Kwon, H. Moo; Klein, Janet D.; Sands, Jeff M.; Kim, Dongun

    2009-01-01

    In our previous studies of varying osmotic diuresis, UT-A1 urea transporter increased when urine and inner medullary (IM) interstitial urea concentration decreased. The purposes of this study were to examine 1) whether IM interstitial tonicity changes with different urine urea concentrations during osmotic dieresis and 2) whether the same result occurs even if the total urinary solute is decreased. Rats were fed a 4% high-salt diet (HSD) or a 5% high-urea diet (HUD) for 2 wk and compared with the control rats fed a regular diet containing 1% NaCl. The urine urea concentration decreased in HSD but increased in HUD. In the IM, UT-A1 and UT-A3 urea transporters, CLC-K1 chloride channel, and tonicity-enhanced binding protein (TonEBP) transcription factor were all increased in HSD and decreased in HUD. Next, rats were fed an 8% low-protein diet (LPD) or a 0.4% low-salt diet (LSD) to decrease the total urinary solute. Urine urea concentration significantly decreased in LPD but significantly increased in LSD. Rats fed the LPD had increased UT-A1 and UT-A3 in the IM base but decreased in the IM tip, resulting in impaired urine concentrating ability. The LSD rats had decreased UT-A1 and UT-A3 in both portions of the IM. CLC-K1 and TonEBP were unchanged by LPD or LSD. We conclude that changes in CLC-K1, UT-A1, UT-A3, and TonEBP play important roles in the renal response to osmotic diuresis in an attempt to minimize changes in plasma osmolality and maintain water homeostasis. PMID:18945830

  15. Renal angiotensin II type-2 receptors are upregulated and mediate the candesartan-induced natriuresis/diuresis in obese Zucker rats.

    PubMed

    Hakam, Amer C; Hussain, Tahir

    2005-02-01

    Recently, there has been a growing interest in studying the role of angiotensin II type-2 (AT(2)) receptor in renal/cardiovascular function in pathological conditions. The present study was designed to determine the functional role of the AT(2) receptors on natriuresis/diuresis and compare the level of the tubular AT(2) receptor expression in obese and lean Zucker rats (12 weeks old). Under anesthesia, candesartan (angiotensin II type 1 [AT(1)]-specific antagonist; 100 microg/kg bolus) produced natriuresis/diuresis to a greater degree in obese than in lean rats. The specific AT(2) antagonist PD123319 (50 microg/kg per minute) after candesartan administration abolished the natriuretic/diuretic effects of candesartan in obese rats but not in lean rats. Infusion of AT(2) receptor agonist, CGP-42112A (1 microg/kg per minute), produced greater increase in sodium and urine excretion over basal in obese than in lean rats. The presence of the AT(2) receptor expression in the brush-border and basolateral membranes was confirmed by Western blotting using specific antibody and antigen-blocking peptide. Densitometric analysis of the bands revealed approximately 1.5- to 2.0-fold increase in the AT(2) receptor proteins in both membranes of obese compared with lean rats. Our results suggest upregulation of the AT(2) receptors, which play a role in mediating the natriuretic/diuretic effects of AT(1) receptor blockers in obese Zucker rats. We speculate that AT(2) receptors, by promoting sodium excretion, may protect obese Zucker rats against blood pressure increase associated with sodium and water retention.

  16. Efficacy of Bolus-dose Phenylephrine for Peri-intubation Hypotension.

    PubMed

    Panchal, Ashish R; Satyanarayan, Arthi; Bahadir, Jenna D; Hays, Daniel; Mosier, Jarrod

    2015-10-01

    Intubation in hypotensive emergency department (ED) patients may increase the risk of life-threatening complications such as hypoperfusion and cardiovascular collapse. Peripherally administered, diluted "push-dose" phenylephrine has been advocated to treat peri-intubation hypotension, however, its effectiveness is unknown. To investigate the efficacy and usage patterns of bolus-dose phenylephrine for peri-intubation hypotension at an academic medical center. A retrospective chart review of all adult intubated, hypotensive patients (systolic blood pressure [SBP] < 90 mm Hg) over 12 months was conducted. During the peri-intubation period (30-min prior to/after intubation), the effect of phenylephrine was evaluated pre/post drug administration by comparing SBP, diastolic blood pressure (DBP), and heart rate (HR). A total of 119 patients met eligibility criteria. Phenylephrine was given to 29/119 (24%) patients and 20 (17%) were treated during the peri-intubation period. Phenylephrine was given for many different conditions, and treatment timing varied greatly. Phenylephrine was given with other vasopressors 70% of the time (14/20), however, the timing of vasopressor infusion also varied greatly. When phenylephrine was given during the peri-intubation period, there were significant increases in SBP and DBP (p < 0.01) with no change in HR. In this academic ED, bolus-dose phenylephrine was used by practitioners without a systematic pattern. Although phenylephrine improved hemodynamics, it is possible that nonsystematic use of phenylephrine may cause inadvertent negative effects. Further studies will need to be conducted to better understand the best practices for use of phenylephrine. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Efficacy of atomoxetine versus midodrine for the treatment of orthostatic hypotension in autonomic failure.

    PubMed

    Ramirez, Claudia E; Okamoto, Luis E; Arnold, Amy C; Gamboa, Alfredo; Diedrich, André; Choi, Leena; Raj, Satish R; Robertson, David; Biaggioni, Italo; Shibao, Cyndya A

    2014-12-01

    The clinical presentation of autonomic failure is orthostatic hypotension. Severely affected patients require pharmacological treatment to prevent presyncopal symptoms or frank syncope. We previously reported in a proof of concept study that pediatric doses of the norepinephrine transporter blockade, atomoxetine, increases blood pressure in autonomic failure patients with residual sympathetic activity compared with placebo. Given that the sympathetic nervous system is maximally activated in the upright position, we hypothesized that atomoxetine would be superior to midodrine, a direct vasoconstrictor, in improving upright blood pressure and orthostatic hypotension-related symptoms. To test this hypothesis, we compared the effect of acute atomoxetine versus midodrine on upright systolic blood pressure and orthostatic symptom scores in 65 patients with severe autonomic failure. There were no differences in seated systolic blood pressure (means difference=0.3 mm Hg; 95% confidence [CI], -7.3 to 7.9; P=0.94). In contrast, atomoxetine produced a greater pressor response in upright systolic blood pressure (means difference=7.5 mm Hg; 95% CI, 0.6 to 15; P=0.03) compared with midodrine. Furthermore, atomoxetine (means difference=0.4; 95% CI, 0.1 to 0.8; P=0.02), but not midodrine (means difference=0.5; 95% CI, -0.1 to 1.0;