Search Results
Results 501 - 550 of 1286
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Wiger P - - 1998
OBJECTIVES: To study the effects of limb elevation on abnormally increased intramuscular pressure (IMP) and blood perfusion pressure in the anterior compartment of the leg. DESIGN: An experimental cross-over design. The test leg was elevated and the control leg was kept at heart level. PARTICIPANTS: Eight healthy subjects with a ...
Stotz-Potter E - - 1998
The mediodorsal nucleus of the thalamus (MD) has connections with central autonomic centers involved in cardiovascular control and undergoes severe degeneration in fatal familial insomnia, a human disease characterized by progressive dysautonomia. Microinjections of the GABAA antagonist bicuculline methiodide (BMI) into the medial and central portion of the MD lead ...
Klein A L - - 1998
Aging influences pulmonary venous flow and mitral inflow velocities. The duration of pulmonary venous atrial reversal flow exceeds that of the mitral inflow A wave in patients with left ventricular end-diastolic pressures greater than 15 mm Hg. The objective of this study was to investigate the effect of age on ...
Bicchi M - - 1998
Felodipine is a second-generation dihydropyridine calcium antagonist used to treat mild to moderate arterial hypertension. The authors used venous occlusion plethysmography to study the effect of this drug on lower limb arterial inflow and venous outflow in 10 at rest patients with mild essential hypertension. They also sought correlations between ...
Edouard D A - - 1998
To assess the contribution of the arterial and venous systems in the hemodynamic changes of normal pregnancy, we studied blood flow, vascular resistance, venous tone, and the viscoelastic properties ("creep") of the upper and lower limbs (using plethysmography), aortic distensibility (using pulse wave velocity measurements), and cardiac dimensions (using echocardiography) ...
Robert Y C YC University Eye Department Nord II, University of Zurich, - - 1998
STUDY OBJECTIVE. To determine the effect of different positional degrees on hemodynamics, especially central venous pressure and intraocular pressure, and a possible interrelationship, during laparoscopic surgery. SETTING. University teaching hospital (Canadian Task Force classification II-1). Seven women undergoing elective gynecologic laparoscopy. The women were monitored for heart rate, partial pressure ...
Dabrowiecki S - - 1998
To study the influence of venous hypertension, which develops in lower limbs under pneumoperitoneal pressure, on microcirculation, plethysmographic measurements were performed in patients before and during laparoscopic and traditional (open) cholecystectomy. During laparoscopy, isovolumetric venous pressure (estimate of capillary pressure), and filtration coefficient (estimate of patent capillary surface) decreased, which ...
Zhang Y - - 1998
The significance of the sympathetic nervous system (SNS) in regulating peripheral vascular resistance and cardiac function in fish has been well established, whereas its effect on venous function in vivo is unknown. Two protocols were employed in the present study to evaluate SNS effects on the venous system in intact, ...
Fukuoka M - - 1998
Foot venous pressure measurement is considered to be useful for assessing lower limb venous insufficiency, because venous hypertension is the main factor predisposing to venous insufficiency. In this study, we investigated the utility of foot venous pressure measurement in the evaluation of venous insufficiency. A total of 148 limbs of ...
Becker K K - - 1998
Complications associated with pulmonary artery catheters (PACs) include interpretation errors, insertion problems, sepsis, thrombosis, and dysrhythmias. Alternatives to the use of PACs include the central venous pressure catheter, measurement of cardiac output by thoracic electrical bioimpedance, gastric tonometry and the measurement of serum lactate level, and the still to be ...
Thorne S A - - 1998
AIMS: Protein losing enteropathy is a serious complication of Fontan surgery. The aim of this study was to investigate gastro-intestinal protein loss in adults with congenital heart disease, both with and without Fontan surgery, and to correlate findings with systemic venous pressure. METHODS AND RESULTS: Forty eight patients were studied. ...
Rostrup M - - 1998
Arterial and venous plasma catecholamine responses to 15 min of cycling at 60% of maximal oxygen uptake were examined 11 times during exercise and recovery in nine young men. Intra-arterial blood pressure, heart rate and oxygen uptake were recorded continuously. All variables increased significantly during the initial 4 min, after ...
Gamble J - - 1998
1. We studied human lower limbs to test the hypothesis that the application of small cumulative venous congestion pressure steps is associated with a reduction in precapillary resistance. 2. Strain gauge plethysmography was performed on twenty-one young subjects (22.7 +/- 0.6 years). At each of the small cumulative pressure steps, ...
Besarab A - - 1998
The measurement of intra-access pressure (P[IA]) normalized by mean arterial BP (MAP) helps detect venous outlet stenosis and correlates with access blood flow. However, general use of P(IA)/MAP is limited by time and special equipment costs. Bernoulli's equation relates differences between P(IA) (recorded by an external transducer as PT) and ...
Halliwill J R - - 1998
Lower body negative pressure is frequently used to simulate orthostasis. Prior data suggest that venous pooling in abdominal or pelvic regions may have major hemodynamic consequences. Therefore, we developed a simple paradigm for assessing regional contributions to venous pooling during lower body negative pressure. Sixteen healthy men and women underwent ...
Scott S S - - 1998
BACKGROUND: Measurements of central venous pressure are generally obtained through one of the three ports of centrally placed triple-lumen catheters. However, no scientifically based literature is available that guides clinical practice and indicates which of the lumens is most appropriate for obtaining these measurements. OBJECTIVE: To determine if a difference ...
Ljutić D - - 1998
Fourteen patients (7 females and 7 males, mean age 51.9 +/- 11.6 years) were studied to find out whether there is a connection between the QTc interval (a diagnostic tool for evaluating autonomic neuropathy) and venous reactivity in uremics on chronic hemodialysis. The QT interval was measured using standard lead ...
Katzgraber F - - 1998
Although venous air embolism is a known complication in medical practice in general, only a single case of upper gastrointestinal endoscopy complicated by venous air embolism with consecutive acute cardiovascular failure has so far been described in literature. Here we show that gastroscopy may be accompanied by massive, i.e. fatal ...
Zachrisson H - - 1998
Judgement of deep venous function may be necessary before surgery for superficial vein incompetence is performed. Assessment of deep venous function needs selective entrapment of superficial venous compartments between the ankle and knee, which may not be guaranteed if conventional tourniquets are used. This study was, therefore, aimed at modifying ...
Leftheriotis G - - 1998
Early post-operative ambulation (< 3 days) is expected to decrease the risk of venous thrombosis, whereas late ambulation (> 7 days) increases the risk of orthostatic hypotension. The effect of post-operative bed rest on calf vein compliance was studied before (D - 1) and 7 days (D + 7) after ...
Hata M - - 1998
Excessive bleeding is a significant problem during total sacrectomy. Ligation of the internal iliac veins to control bleeding from the pelvic venous plexus has been reported to be mandatory. However, despite ligation of the internal iliac veins, excessive hemorrhage from the pelvic and epidural venous plexuses is often encountered. We ...
Mostoufi-Moab S - - 1998
We examined the effects of unilateral, nondominant forearm training (4 wk) on blood pressure and forearm metabolites during ischemic and nonischemic rhythmic handgrip (30 1-s contractions/min at 25% maximal voluntary contraction). Contractions were performed by 10 subjects with the forearm enclosed in a pressurized Plexiglas tank to induce ischemic conditions. ...
Vayssettes-Courchay C - - 1997
1. Saphenous vein reactivity was recorded in the anaesthetized dog by use of an ultrasonic echo-tracking device to measure the internal diameter of the vein and to calculate the venous compliance. This method was used to investigate the effects of a new partial alpha1/alpha2-adrenoceptor agonist, S 18149, on the canine ...
Fromy B - - 1997
OBJECTIVE: The balance between the apparent beneficial effect and the risk of arterial ischaemia resulting from an external uniform compression is unclear. The purpose of this study was to determine the effects of a positive uniform compression on the lower limb circulation until a critical threshold was reached. METHODS: We ...
Wood G - - 1997
OBJECTIVE: To determine whether stopping nitroglycerin and sodium nitroprusside (both vasodilators) infusions in hypertensive, postcardiac surgical patients requiring a high FIO2 improves PaO2 and venous admixture. DESIGN: Prospective, clinical trial. SETTING: Intensive care unit in a university-affiliated hospital. PATIENTS: Thirty postcardiac surgical patients who, because of high FIO2 requirements, did ...
Zamboni P - - 1997
In spite of its invasiveness, measurement of ambulatory venous pressure (AVP) is widely considered the gold standard measurement of venous function. We studied a technique for noninvasive ultrasonographic AVP determination in superficial venous incompetence. A linear relationship between venous pressure (measured by echo-guided venous puncture) and diameter (measured by transverse ...
Veraart J C - - 1997
BACKGROUND: Elastic compression stockings are widely used medical devices for the prevention of edema and treatment of venous diseases. Many beneficial effects have been described in the past. The exact amount of pressure underneath elastic compression stockings at different areas of the leg remains controversial. OBJECTIVE: To examine the pressure ...
Lommi J - - 1997
OBJECTIVES: Increased activity of pro-inflammatory cytokines in the circulation has been observed in many, though not all, patients with congestive heart failure. To identify the predictors of cytokine activation in congestive heart failure, we assessed the relationship of peripheral and hepatic venous cytokines to central haemodynamics, neuroendocrine status and intermediary ...
Christ F - - 1997
1. Venous congestion strain-gauge plethysmography enables the non-invasive assessment of arterial blood flow, fluid filtration capacity (Kf), venous pressure (Pv) and isovolumetric venous pressure (Pvi) in man. One of the major assumptions of this technique, that cuff pressure (Pcuff) applied to the limb equals Pv at the level of the ...
Federspiel W J - - 1997
A potentially attractive support device for patients with acute respiratory failure is an intravenous membrane oxygenator. One problem, however, is that the membrane surface area required for sufficient gas exchange can unduly increase vena caval pressure drop and impede venous return. The purpose of this study was to design and ...
Mangiafico R A - - 1997
The aim of the study was to investigate the release of endothelin-1 (ET-1) in normal and varicose saphenous veins at baseline and after venous stasis test. Ten patients (eight women and two men, mean age 43 +/- 4) with primarily varicose great saphenous veins and ten controls (eight women and ...
Pinto A - - 1997
Thirty adult patients with distal, monolateral deep vein thrombosis of the lower limbs were randomly treated for sixty days either with subcutaneous Ca-Heparin or with Sulodexide, administered IM for ten days and orally for fifty days. The thrombus accretion above the knee, the venous pressures of the affected leg, the ...
Ibegbuna V - - 1997
OBJECTIVE: To investigate the effect of lightweight graduated elastic stockings on venous haemodynamics. DESIGN: The amount of reflux and function of the calf muscle pump were evaluated before and after the application of lightweight graduated compression stockings using air-plethysmography. Each patient acted as his own control and the Wilcoxon rank ...
Johansen L B - - 1997
The hypothesis was tested that the abdominal area constitutes an important reservoir for central blood volume expansion (CBVE) during water immersion in humans. Six men underwent 1) water immersion for 30 min (WI), 2) water immersion for 30 min with thigh cuff inflation (250 mmHg) during initial 15 min to ...
Sugerman H J - - 1997
OBJECTIVES: To determine whether intra-abdominal pressure (as estimated from urinary bladder pressure) is elevated in patients with central obesity (as measured by sagittal abdominal diameter) and pseudotumor cerebri and whether this increased intra-abdominal pressure is associated with increased pleural pressure and cardiac filling pressure, implying a resistance to venous return ...
Sahin G - - 1997
The central effects of capsaicin, veratrine, histamine and bradykinin were studied by injecting them directly into the oerebrospinal fluid and their peripheral effects were examined by injecting into femoral vein. Our experiments were performed in Na-pentobarbital-anaesthetized dogs. Tidal volume (VT), respiratory frequency (f/min), systemic arterial pressure (BP) were recorded. A ...
Jean G - - 1997
Central venous catheters are commonly used for haemodialysis patients and represent, in our centre, about 15% of the permanent vascular accesses with a total number of more than 230 central venous catheters over the last 10 years. Inadequate blood flow may occur and upsets the nurses, the patients, and the ...
Shanley C J - - 1997
To determine whether changes mixed-venous PCO2 or PO2 affect cardiac output independent of changes in arterial blood gases, we used extracorporeal gas exchange to increase mixed-venous PCO2 or decrease mixed-venous PO2 in adult sheep. Sheep were anesthetized, mechanically ventilated, and connected to a veno-venous extracorporeal circuit. The circuit included a ...
Saharay M - - 1997
It has been suggested that leukocyte trapping and activation in the microcirculation of the leg skin causes lipodermatosclerosis and ulceration in patients with chronic venous disease. Ambulatory venous hypertension is accepted as the physiologic factor that leads to ulceration. We investigated leukocyte endothelial adhesion in patients who were subjected to ...
Torii R - - 1997
Plasma arginine vasopressin (AVP) concentration is reduced in human subjects during prolonged saturation dive exposures of 4 atmospheres absolute (atm abs) and greater. The objectives of the present study were to determine if AVP would be reduced in eight male subjects during a 1-h exposure of 3 atm abs air ...
Yoxall C W - - 1997
Measurement of the oxygenation of the peripheral tissues provides useful information about tissue perfusion. A method is described for the measurement of peripheral venous oxyhaemaglobin saturation (SvO2) in the adult forearm by a noninvasive technique, near infrared spectroscopy (NIRS) with venous occlusion. A series of studies is performed on healthy ...
Ruess L - - 1997
PURPOSE: To determine in-line pressures generated in small-bore central venous catheters during power injection of computed tomographic (CT) contrast media. MATERIALS AND METHODS: Five 3.0-7.0-F central venous catheters for pediatric patients were tested at full and half lengths in vitro. In-line pressures were measured during power injection of three contrast ...
Bastian A - - 1997
A patient with recurrent acute pancreatitis developed pericardial effusion and cardiac tamponade. His systolic blood pressure fell to 70 mmHg and sinus tachycardia (150/min) developed. The central venous pressure rose from 3 cm H2O to 27 cm H2O. A chest radiograph showed an enlargement of the cardiac shadow. Pericardial paracentesis ...
Krantz T - - 1997
BACKGROUND: We evaluated the ability of the standards issued by the Danish Society of Anaesthesiologists to reflect a blood loss. METHODS: In 9 pigs bled (0-24 ml kg-1 and retransfused (to 28 ml kg-1) during halothane anaesthesia central cardiovascular, thoracic electrical impedance (TI), oxygen, acid-base and temperature variables were recorded. ...
Martin D S - - 1997
Venous capacitance plays an important role in the control of cardiac output. However, the central nervous system sites and neurochemical signals involved in modulating venous function remain to be fully elucidated. The hypothalamic paraventricular nucleus (PVN) is an important site modulating autonomic outflow to the cardiovascular system. The present study ...
Bazin J E - - 1997
This study was designed to determine the conditions that promote carbon dioxide embolism after venous injury during laparoscopy in pigs. Injury to an iliac vein was filmed during laparoscopy in the presence of a pneumoperitoneum created at increasing pressures from 0 to 30 mm Hg in 5-mm Hg increments. At ...
Dillon R S - - 1997
Effective peripheral blood flow is positively related to cardiac output and gravity (part dependent) and inversely related to gravity (part elevated), venous pressure, interstitial fluid pressure, degree of peripheral neuropathy, arteriosclerotic and thrombotic arterial obstructions, and infection. These factors are considered in the operation of the end-diastolic pneumatic boot in ...
Palmon S C - - 1997
Venous air embolism (VAE) can be a lethal complication of surgical procedures, during which (1) venous pressure at the site of surgery is subatmospheric or (2) gas is forced under pressure into a body cavity. Though classically associated with neurosurgery, VAE is also a potential complication of laparoscopic, pelvic, and ...
Yoshimoto Y - - 1997
A canine model of cortical vein occlusion was used to evaluate whether data obtained from monitoring venous stump pressure could help predict cerebral infarction after venous obstruction. Following bilateral parasagittal craniotomy, the cortical vein in each hemisphere was temporarily occluded and the increase in pressure was directly measured. Permanent venous ...
Lee H W - - 1997
Venous bleeding during transsphenoidal surgery for resection of pituitary tumors is a common problem that interferes with the performance of the surgical procedure. In this study, data were collected prospectively from 50 patients to determine whether there were pre- or intraoperative factors (e.g., patient demographics, type and grade of pituitary ...
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