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orthostatic hypotension hypovolemia

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https://www.readbyqxmd.com/read/26205572/lower-body-negative-pressure-historical-perspective-research-findings-and-clinical-applications
#1
George J Crystal, M Ramez Salem
Lower body negative pressure (LBNP) is a technique that redistributes blood from the upper body to the dependent regions of the pelvis and legs, thus reducing central venous pressure and venous return. The subject is placed in a cylindrical air-tight metal tank, which is sealed at the level of the iliac crests, and subatmospheric pressure is produced using a vacuum pump. This article reviews the historical background, physiological effects, research findings, and clinical applications of LBNP. LBNP is found in both the basic science and clinical literature, encompassing its diverse investigational and clinical applications...
April 2015: Journal of Anesthesia History
https://www.readbyqxmd.com/read/26198889/postural-tachycardia-syndrome-beyond-orthostatic-intolerance
#2
REVIEW
Emily M Garland, Jorge E Celedonio, Satish R Raj
Postural tachycardia syndrome (POTS) is a form of chronic orthostatic intolerance for which the hallmark physiological trait is an excessive increase in heart rate with assumption of upright posture. The orthostatic tachycardia occurs in the absence of orthostatic hypotension and is associated with a >6-month history of symptoms that are relieved by recumbence. The heart rate abnormality and orthostatic symptoms should not be caused by medications that impair autonomic regulation or by debilitating disorders that can cause tachycardia...
September 2015: Current Neurology and Neuroscience Reports
https://www.readbyqxmd.com/read/25684232/orthostatic-hypotension-of-unknown-cause-unanticipated-association-with-elevated-circulating-n-terminal-brain-natriuretic-peptide-nt-probnp
#3
Balaji Krishnan, Margarita Patarroyo-Aponte, Daniel Duprez, Marc Pritzker, Emil Missov, David G Benditt
BACKGROUND: The pathophysiology of orthostatic hypotension (OH) is multifactorial, with the most frequent causes being adverse effects of cardioactive drugs. In 20%-40% of cases, the etiology is unknown. In recent reports, altered levels of endogenous neuropeptides have been observed in noncardiac syncope, but B-type natriuretic peptide (BNP) and its amino-terminal cleavage fragment (NT-proBNP) have not been studied. OBJECTIVE: The purpose of this study was to assess the possibility that BNP with its diuretic and vasorelaxant properties could contribute to OH...
June 2015: Heart Rhythm: the Official Journal of the Heart Rhythm Society
https://www.readbyqxmd.com/read/25569595/diagnosis-and-treatment-of-cerebral-salt-wasting-syndrome-with-cryptococcal-meningitis-in-hiv-patient
#4
Sunggeun Lee, Anitsira Collado, Montish Singla, Roger Carbajal, Ashok Chaudhari, Donald Baumstein
Hyponatremia is one of the most common electrolyte imbalances in HIV patients. The differential diagnosis may include hypovolemic hyponatremia, syndrome of inappropriate antidiuretic hormone secretion (SIADH), and adrenal insufficiency. Here, we describe a case of hyponatremia secondary to cerebral salt wasting syndrome (CSWS) in an HIV patient with cryptococcal meningitis. A 52-year-old man with a history of diabetes and HIV was admitted for headache and found to have cryptococcal meningitis. He was also found to have asymptomatic hyponatremia...
March 2016: American Journal of Therapeutics
https://www.readbyqxmd.com/read/25071585/neurohumoral-mechanisms-associated-with-orthostasis-reaffirmation-of-the-significant-contribution-of-the-heart-rate-response
#5
REVIEW
Victor A Convertino
The inability to compensate for acute central hypovolemia underlies the clinical development of orthostatic hypotension and instability (e.g., syncope). Although neuro-humoral control of both cardiac output and peripheral vascular resistance contributes to hemodynamic stability during orthostasis, a notion has been proposed that the failure of adequate peripheral vascular constriction rather than cardiac responses represents the primary mechanism underlying the development of orthostatic intolerance. This review article provides an opportunity to present compelling evidence captured over the past 30 years in our laboratory to support the concept that neural-mediated tachycardia during orthostasis in healthy individuals represents a critical response to tolerating acute reduction in central blood volume in addition to, and independent of, peripheral vascular constriction...
2014: Frontiers in Physiology
https://www.readbyqxmd.com/read/24778619/arterial-pressure-and-cerebral-blood-flow-variability-friend-or-foe-a-review
#6
REVIEW
Caroline A Rickards, Yu-Chieh Tzeng
Variability in arterial pressure and cerebral blood flow has traditionally been interpreted as a marker of cardiovascular decompensation, and has been associated with negative clinical outcomes across varying time scales, from impending orthostatic syncope to an increased risk of stroke. Emerging evidence, however, suggests that increased hemodynamic variability may, in fact, be protective in the face of acute challenges to perfusion, including significant central hypovolemia and hypotension (including hemorrhage), and during cardiac bypass surgery...
2014: Frontiers in Physiology
https://www.readbyqxmd.com/read/24760494/low-pressure-spinal-fluid-leak-headache
#7
REVIEW
Roderick C Spears
Low cerebrospinal fluid (CSF) pressure results in neurologic deficits, of which the most common manifestation is headache. Typically, the headache is postural - and specifically, orthostatic - in presentation. There are three hypotheses to explain the occurrence of headache associated with low CSF fluid. The first is traction on pain-sensitive intracranial and meningeal structures; the second is CSF hypovolemia; and the third is spinal loss of CSF resulting in increased compliance at the caudal end of the CSF space...
June 2014: Current Pain and Headache Reports
https://www.readbyqxmd.com/read/24711524/reduced-cerebral-blood-flow-with-orthostasis-precedes-hypocapnic-hyperpnea-sympathetic-activation-and-postural-tachycardia-syndrome
#8
Andrew T Del Pozzi, Christopher E Schwartz, Deepali Tewari, Marvin S Medow, Julian M Stewart
Hyperventilation and reduced cerebral blood flow velocity can occur in postural tachycardia syndrome (POTS). We studied orthostatically intolerant patients, with suspected POTS, with a chief complaint of upright dyspnea. On the basis of our observations of an immediate reduction of cerebral blood flow velocity with orthostasis, we hypothesize that the resulting ischemic hypoxia of the carotid body causes chemoreflex activation, hypocapnic hyperpnea, sympathetic activation, and increased heart rate and blood pressure in this subset of POTS...
June 2014: Hypertension
https://www.readbyqxmd.com/read/24470768/misdiagnosed-spontaneous-intracranial-hypotension-complicated-by-subdural-hematoma-following-lumbar-puncture
#9
Nissrine Louhab, Nawal Adali, Mehdi Laghmari, Wafae El Hymer, Said Ait Ben Ali, Najib Kissani
INTRODUCTION: Spontaneous intracranial hypotension is an infrequent cause of secondary headache due to cerebrospinal fluid (CSF) hypovolemia. OBJECTIVE: To describe a case of headache revealing spontaneous intracranial hypotension complicated by subdural hematoma following lumbar puncture. OBSERVATION: A 34-year-old man presented with acute postural headache. The first cerebral computed tomography scan was normal. Lumbar puncture showed hyperproteinorachy at 2 g/L with six lymphocytic cells...
2014: International Journal of General Medicine
https://www.readbyqxmd.com/read/24375330/cerebral-venous-thrombosis-an-unexpected-complication-from-spinal-surgery
#10
REVIEW
Bruno Lourenço Costa, Motasem Shamasna, Joana Nunes, Florbela Magalhães, António Júdice Peliz
PURPOSE: To provide new insights into the pathophysiology, prevention and diagnosis of cerebral venous thrombosis (CVT) associated with iatrogenic cerebrospinal fluid (CSF) leaks and/or external CSF drainage. METHODS: Case report and literature review. RESULTS: We describe the case of a 30-year-old woman who developed a CSF fistula after lumbar spinal surgery. The treatment included rest, hydration, caffeine, and continuous lumbar CSF drainage...
May 2014: European Spine Journal
https://www.readbyqxmd.com/read/24365296/transient-loss-of-consciousness-and-syncope
#11
REVIEW
Claudio L Bassetti
Syncope describes a sudden and brief transient loss of consciousness (TLOC) with postural failure due to cerebral global hypoperfusion. The term TLOC is used when the cause is either unrelated to cerebral hypoperfusion or is unknown. The most common causes of syncopal TLOC include: (1) cardiogenic syncope (cardiac arrhythmias, structural cardiac diseases, others); (2) orthostatic hypotension (due to drugs, hypovolemia, primary or secondary autonomic failure, others); (3) neurally mediated syncope (cardioinhibitory, vasodepressor, and mixed forms)...
2014: Handbook of Clinical Neurology
https://www.readbyqxmd.com/read/24339614/two-cases-of-medically-refractory-spontaneous-orthostatic-headaches-with-normal-cerebrospinal-fluid-pressures-responding-to-epidural-blood-patching-intracranial-hypotension-versus-hypovolemia-and-the-need-for-clinical-awareness
#12
Kaukab M Hassan, Sudeep Prakash, S S Majumdar, Anup Banerji
The diagnosis of spontaneous intracranial hypotension or cerebrospinal fluid (CSF) hypovolemia syndrome requires a high index of suspicion and meticulous history taking, demonstration of low CSF pressure and/or neuroimaging features. A 31-year-old male, presented with subacute onset moderate occipital and sub-occipital headaches precipitated by upright posture and relieved on recumbency and neck pain for 2 years. There was no trauma, cranial/spinal surgery. Clinical examination was normal and CSF opening pressure and laboratory study were normal...
October 2013: Annals of Indian Academy of Neurology
https://www.readbyqxmd.com/read/24261222/-the-present-state-and-view-of-the-cerebrospinal-fluid-hypovolemia-research
#13
Masamichi Shinonaga
Spontaneous intracranial hypotension is a rare disease characterized by orthostatic headache, low cerebrospinal fluid pressure and diffuse dural enhancement in brain MRI. German neurologist Schaltenbrand reported that orthostatic headache by low cerebrospinal fluid pressure in 1938. This disease came to be known after development of radiological diagnosis in 1990'. The author reported that cerebrospinal fluid leak is induced in the whiplash sequelae after traffic accident in 2003. Cerebrospinal fluid hypovolemia got into the news social...
October 2013: Nihon Rinsho. Japanese Journal of Clinical Medicine
https://www.readbyqxmd.com/read/23808630/spontaneous-low-pressure-low-csf-volume-headaches-spontaneous-csf-leaks
#14
REVIEW
Bahram Mokri
Spontaneous intracranial hypotension typically results from spontaneous cerebrospinal fluid (CSF) leak, often at spine level and only rarely from skull base. Once considered rare, it is now diagnosed far more commonly than before and is recognized as an important cause of headaches. CSF leak leads to loss of CSF volume. Considering that the skull is a rigid noncollapsible container, loss of CSF volume is typically compensated by subdural fluid collections and by increase in intracranial venous blood which, in turn, causes pachymeningeal thickening, enlarged pituitary, and engorgement of cerebral venous sinuses on magnetic resonance imaging (MRI)...
July 2013: Headache
https://www.readbyqxmd.com/read/23491955/-diuretics-in-patients-with-renal-diseases
#15
Ritz, Schömig
The main indications for diuretic treatment of renal patients are edema and hypertension. Pharmakokinetics and pharmacodynamics of diuretics are altered in patients with proteinuria and/or impaired renal function. These patients exhibit avid sodium retention. Diuretics are partially inactivated by binding to proteins in tubular fluid. The natriuretic response to diuretics is limited by counter-regulation, specifically increased proximal tubular reabsorption in response to hypovolemia and increased distal tubular sodium reabsorption in response to increased sodium load...
June 1, 2000: Therapeutische Umschau. Revue Thérapeutique
https://www.readbyqxmd.com/read/23469486/-orthostatic-hypotension-definition-symptoms-assessment-and-pathophysiology
#16
M Tyberghein, J-C Philips, J-M Krzesinski, A J Scheen
Orthostatic hypotension (OH) is defined by a drop in arterial blood pressure (BP) of at least 20 mmHg for systolic BP and 10 mmHg for diastolic BP after standing. Symptoms are generally quite typical, but may also be rather vague. Diagnosis may be easily made by the physician in his/ her office, and confirmed, if necessary, by more sophisticated measurements. Pathophysiology is generally rather complex, but mostly involves a defect in the autonomic nervous system, in its sympathetic component. Failure of peripheral vasoconstriction seems to play a more important role than the defect in reflex tachycardia...
February 2013: Revue Médicale de Liège
https://www.readbyqxmd.com/read/23465770/postural-tachycardia-syndrome-in-children-and-adolescents
#17
REVIEW
Imad T Jarjour
Postural tachycardia syndrome is a chronic condition with frequent symptoms of orthostatic intolerance or sympathetic activation and excessive tachycardia while standing, without significant hypotension. Orthostatic symptoms include dizziness, lightheadedness, blurring of vision, near faints, weakness in legs, poor concentration, nausea, and headaches. Somatic symptoms include fatigue, sleep disorder, widespread pain, abdominal pain, and menstrual irregularities. Psychological problems may overlap with physical complaints...
March 2013: Seminars in Pediatric Neurology
https://www.readbyqxmd.com/read/23122672/postural-tachycardia-syndrome-a-heterogeneous-and-multifactorial-disorder
#18
REVIEW
Eduardo E Benarroch
Postural tachycardia syndrome (POTS) is defined by a heart rate increment of 30 beats/min or more within 10 minutes of standing or head-up tilt in the absence of orthostatic hypotension; the standing heart rate is often 120 beats/min or higher. POTS manifests with symptoms of cerebral hypoperfusion and excessive sympathoexcitation. The pathophysiology of POTS is heterogeneous and includes impaired sympathetically mediated vasoconstriction, excessive sympathetic drive, volume dysregulation, and deconditioning...
December 2012: Mayo Clinic Proceedings
https://www.readbyqxmd.com/read/22551332/spontaneous-intracranial-hypotension-a-case-study
#19
Tammy L Tyree, Randall Porter
PURPOSE: 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). DATA SOURCES: 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. CONCLUSIONS: SIH is a condition that typically occurs without a traumatic event, although it can be associated with minor trauma...
May 2012: Journal of the American Academy of Nurse Practitioners
https://www.readbyqxmd.com/read/22445241/-orthostatic-hypotension-epidemiology-and-mechanisms
#20
Jean-Jacques Monsuez, Romain Beddok, Abdel Mahiou, Alaine Ngaleu, Sid Belbachir
Orthostatic hypotension (OH) is defined as a decrease in systolic blood pressure more than or equal to 20mmHg or diastolic more than or equal to 10mmHg within three minutes of standing up. Discharge records for 0.4% of all hospitalizations include OH as a diagnosis. The prevalence of OH is related to aging, reaching 5 to 30% in unselected elders aged more than or equal to 65 years, especially those treated for hypertension and/or living in nursing homes or health care facilities. OH is associated with an increased risk of syncope and subsequent cardiovascular mortality...
November 2012: La Presse Médicale
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