Search Results
Results 301 - 350 of 1286
< 2 3 4 5 6 7 8 9 10 11 12 >
Joseph Mathew - - 2003
INTRODUCTION: Vasospasm after subarachnoid hemorrhage remains a management challenge. The accepted treatment involves hypertensive, hypervolemic, hemodilution therapy. However, there is variation in the application of this treatment. Most authors increase mean arterial pressure (MAP), which can be associated with significant morbidity. Others increase cardiac output (CO). In this study, we ...
Healey Chris - - 2003
Venous hypertension leads to venous stasis ulcers. White cell activation, protein leakage from pressurized capillaries, and cytokine imbalances have all been implicated as indirect effects of venous hypertension that contribute to dermal changes seen in chronic venous insufficiency. The direct effect of increased tissue pressures on dermal elements has not ...
Schadt James C - - 2004
In the conscious rabbit, exposure to an air jet stressor increases arterial pressure, heart rate, and cardiac output. During hemorrhage, air jet exposure extends the blood loss necessary to produce hypotension. It is possible that this enhanced defense of arterial pressure is a general characteristic of stressors. However, some stressors ...
Fukuoka Masato - - 2003
The purpose of this study was to evaluate lower extremity venous function in patients with chronic venous insufficiency, with foot venous pressure (FVP) measurements and air plethysmography (APG). Eighty-five limbs of 63 patients with a history of chronic venous insufficiency (CVI) from 1995 to 1999 were studied. FVP parameters studied ...
Wang Liyun L Department of Orthopaedics, The Mount Sinai School of Medicine, New York, NY 10029, USA - - 2003
This paper addresses the question of whether or not interstitial fluid flow due to the blood circulation accounts for the observed periosteal bone formation associated with comprised venous return (venous stasis). Increased interstitial fluid flow induced by increased intramedullary pressure has been proposed to account for the periosteal response in ...
Alomari Mahmoud A - - 2004
The main purpose of the present study was to examine the relationships between measures of fitness [estimated peak oxygen consumption (V(O2) peak) and handgrip strength] and forearm vascular function in 55 young (22.6 +/- 3.5 yr) adults. In addition, the present study considered methodological and technical aspects regarding the examination ...
Milhoan K A - - 2004
After the bidirectional cavopulmonary or Fontan operation, the physiologic consequence is passive flow of the systemic venous return to the pulmonary arteries. Knowledge of pulmonary artery pressure (PA) is valuable in the management of these patients, and obtaining this information without the need for a central line or cardiac catheterization ...
Desmond Joel - - 2003
A short cut review was carried out to establish whether femoral central venous lines were as reliable as subclavian or jugular lines at assessing right atrial filling pressure. Altogether 141 papers were found using the reported search, of which seven presented the best evidence to answer the clinical question. The ...
Tkachenko B I - - 2003
Experiments on cats treated with nitroglycerin showed dynamic relationship between changes in caval venous flows: blood flow increased in the superior vena cava and decreased in the inferior vena cava. Blood pressure in the right atrium either decreased, or increased. No significant changes in total venous return were observed during ...
Moore A - - 2003
The ageing process is associated with important changes in the responses of the cardiovascular system to pharmacological stimuli. They are not limited to the arterial system, involved in the modulation of cardiac afterload and vascular resistance, but they also involve the low-resistance capacitance venous system and the heart. The main ...
Schipke J D - - 2003
The static pressure resulting after the cessation of flow is thought to reflect the filling of the cardiovascular system. In the past, static filling pressures or mean circulatory filling pressures have only been reported in experimental animals and in human corpses, respectively. We investigated arterial and central venous pressures in ...
van't Laar A - - 2003
Every doctor should be able to make a probable diagnosis of congestive heart failure by clinical examination. The most revealing clinical sign is an elevated jugular venous pressure. The measurement of this pressure was introduced by Lewis in 1930 and refined and standardised by Borst and Molhuysen in 1952. Still, ...
Wilkens J L - - 2003
In Jasus edwardsii (Hutton) the vascular resistance of each of the seven major arterial systems leaving the heart was increased in response to several of the following neurotransmitters and neurohormones: acetylcholine, adrenalin, serotonin, dopamine, octopamine and peptides proctolin and FLRFamide-related peptide F(1). The resistance to flow through the infrabranchial sinus ...
Bronzetti Gabriele - - 2003
BACKGROUND: Junctional ectopic tachycardia (JET) is a life-threatening arrhythmia producing severe hemodynamic dysfunction, which may complicate the postoperative course of surgery for congenital heart disease. Strict care and a fast and effective antiarrhythmic strategy are essential, because mortality largely depends on the duration of the arrhythmia. METHODS: Seven consecutive neonates ...
Minerick Adrienne Robyn - - 2003
Measurement of venous function in vivo is inherently difficult. In this study, we used the Hilbert transform to examine the dynamic relationships between venous pressure and cardiac output (CO) in rainbow trout whose blood volume was continuously increased and decreased by ramp infusion and withdrawal (I/W). The dorsal aorta and ...
Jorfeldt Lennart - - 2003
Blood flow determinations by venous occlusion plethysmography applying the strain-gauge technique are frequently used. A problem with the strain-gauge technique is that the relationship between venous volume and transmural pressure is not linear and, furthermore, changes with the sympathetic tone. The present study tests the hypothesis that these factors lead ...
Comunale Mark E - - 2003
OBJECTIVE: To determine whether the incidence of protamine-induced pulmonary vasoconstriction (PIPV) is influenced by central venous versus peripheral venous infusion of protamine and whether aspirin ingestion within a week of surgery would decrease the incidence of PIPV. DESIGN: Single-institution, prospective, observational, randomized trial. SETTING: University teaching hospital. PARTICIPANTS: One thousand ...
Jonas Jost B - - 2003
PURPOSE: To determine the central retinal vessel collapse pressure in patients with dilated episcleral veins. METHODS: This clinical noninterventional comparative study included a study group of 10 eyes (6 patients) with dilated episcleral veins, and a control group consisting of 50 eyes of 40 patients with cataract or refractive problems. ...
Jünger M - - 2003
The most important component in the treatment of venous ulcers is compression therapy. The function of compression therapy is the pressure exterted on the extrafascial and intrafascial venous system. Therefore the interface pressure of specially designed compressions stockings for the treatment of venous ulcers are in the focus of interest. ...
Owler Brian K - - 2003
OBJECT: Pseudotumor cerebri, or benign intracranial hypertension, is a condition of raised intracranial pressure in the absence of a mass lesion or cerebral edema. It is characterized by headache and visual deterioration that may culminate in blindness. Pseudotumor cerebri is caused by venous sinus obstruction in an unknown percentage of ...
Sirken Gary R - - 2003
BACKGROUND: Early detection with elective intervention of malfunctioning arteriovenous (AV) grafts improves access viability. Herein, we evaluated outlet venous pressure (OP), normalized by mean arterial blood pressure (MABP), at varying blood flow (Qb) rates in the detection of venous outlet stenosis. METHODS: This single-center, observational study included stable dialysis patients ...
Belcaro G - - 2003
In 20 patients with chronic venous insufficiency and venous hypertension associated with ulcerations, the effects of a new compound, applied onto the skin (Crystacide) were assessed in a randomized, controlled study. Duplex scanning was used to assess the presence of venous obstruction and incompetence, and microcirculatory methods were used to ...
Groothuis Jan T - - 2003
Venous occlusion strain gauge plethysmography (VOP) is based on the assumption that the veins are occluded and arterial inflow is undisturbed by the venous cuff pressure. Literature is not clear concerning the pressure that should be used. The purpose of this study was to determine the optimal venous occlusion pressure ...
Bittl John A - - 2003
Dialysis fistulas and bridge grafts frequently develop outflow stenoses in the venous limb, leading to graft failure. The venous stenoses are fibrotic and require percutaneous transluminal angioplasty with high-pressure balloons. We have encountered venous stenoses in 3 out of 219 hemodialysis patients with graft failure that were undilatable with 6-8 ...
Holmgren Daniel - - 2003
We report a case of recurrent syncope in association with moderate ventricular dysfunction and mild AV-valve regurgitation in an 18-year-old girl, 4 years after she underwent total cavopulmonary connection surgery. Cardiac catheterization revealed a transpulmonary gradient of 1-2 mmHg. During exercise, a dramatic fall in blood pressure and blood oxygenation ...
Jegger David - - 2003
During cardiopulmonary bypass (CPB), venous drainage may be impeded due to small vessel and cannula size or chattering, thus, blood return to the heart-lung machine is reduced. We designed a self-expandable prototype cannula, which is able to maintain the vein open and overcome this problem and analysed its performance capability. ...
Wecht Jill M - - 2003
The purpose of this study was to examine cardiac hemodynamics during acute head-up tilt (HUT) and calf venous function during acute head-down tilt (HDT) in subjects with paraplegia compared with sedentary nondisabled controls. Nineteen paraplegic males (below T6) and nine age-, height-, and weight-matched control subjects participated. Heart rate, stroke ...
Ohnesorge Henning - - 2003
OBJECTIVE: Sepsis or systemic inflammatory response syndrome (SIRS) is often associated with encephalopathy (70%), which has been described as an early symptom resulting in several diseases. The present study investigated somatosensory evoked potentials (SEP) as an indicator or even a predictor of cerebral dysfunction evaluated in an experimental model of ...
Taylor Wendy - - 2003
High-flow AVFs are a challenging problem in the pediatric age group. Venous occlusive changes develop as part of the dynamic response to these fistulas. The development of adequate venous collateral flow circumvents the destructive sequelae of longstanding venous hypertension. Without adequate collaterals, venous hypertension develops. Venous hypertension interferes with CSF ...
Charalambous C - - 2003
We conducted a prospective study to determine the relationship between central (CVP) and peripheral (PVP) venous pressures in critically ill patients. CVP and PVP were measured on five different occasions in 20 critically ill patients in the intensive care unit. Results showed that the mean difference between PVP and CVP ...
Liao Chiang-Hua - - 2003
A male premature newborn was diagnosed as respiratory distress syndrome shortly after birth. Umbilical arterial and venous catheters were inserted. The position of the umbilical venous catheter was erroneous roentgenographically, but return of blood was noted when the catheter was pull back to below the diaphragm. After fluid infusion via ...
Jacks A S - - 2003
Spontaneous retinal venous pulsation is seen as a subtle variation in the calibre of the retinal vein(s) as they cross the optic disc. The physical principles behind the venous pulsations has been the point of much debate. Initial theories suggested that the pulsation occurred because of the rise in intraocular ...
Pottier Pierre - - 2003
We have developed a model of a pre-thrombotic state in rats based on venous stasis induced by partial ligature of the inferior vena cava. The degree of stenosis was calibrated by using variations in upstream venous pressure. Different degrees of stasis were tested in order to obtain a pre-thrombotic state. ...
Chang Shi-Min - - 2003
The role of large superficial veins in the survival of a distally based fasciocutaneous flap with a veno-neuro-adipofascial pedicle was studied in a rabbit model. A sural veno-neuro-fasciocutaneous flap model (6 x 2 cm) with a distally based lesser saphenous veno-neuro-adipofascial pedicle (1.5 cm) was established. Fifteen rabbits were randomly ...
Yamagishi M - - 2002
BACKGROUND: Various vasoactive substances are released during cardiopulmonary bypass. They may deteriorate pulmonary circulation after the Fontan operation. Effects of plasma endothelin-1 (ET-1), a vasoconstricting peptide, on the Fontan circulation have not been investigated. METHODS: Eleven patients (aged 11.1+/-7.5 years) who underwent the modified Fontan operation (group F) and seven ...
Partsch Hugo - - 2002
The aim of this study was to investigate the hemodynamic effects of thigh compression in patients with deep venous incompetence. This diagnostic test study was set in a municipal general hospital. Twelve patients with venous leg ulcers (CEAP classification, C6 Es Ad Pr; four men and eight women), with a ...
Hirai Masafumi - - 2002
BACKGROUND/AIMS: Oedema is one of the most frequent signs of chronic venous insufficiency and may be present at all stages of this disorder. The aim of this study was to compare the effects of four different types of elastic compression stockings on oedema prevention in patients with varicose veins. METHODS: ...
Pranevicius Mindaugas - - 2002
PURPOSE: Flow in areas with increased tissue pressure is described by a Starling resistor and is determined by the inflow pressure (P(i)), the external pressure (P(e)), and the outflow or venous pressure (P(v)). Flow is in Zone 1 at P(e) > P(i) > P(v), Zone 2 at P(i) > P(e) ...
Brengelmann George L - - 2003
A. C. Guyton pioneered major advances in understanding cardiovascular equilibrium. He superimposed venous return curves on cardiac output curves to reveal their intersection at the one level of right atrial pressure (Pra) and flow simultaneously consistent with independent properties of the heart and vasculature. He showed how this point would ...
Nguyen N T - - 2003
BACKGROUND: Pneumoperitoneum (PP) and the reverse Trendelenburg (RT) position have been shown to decrease femoral blood flow, resulting in venous stasis. However the effects of PP and RT on femoral venous flow have not been evaluated in morbidly obese patients undergoing laparoscopic gastric bypass (GBP). We analyzed the effects of ...
Frinak Stanley - - 2002
BACKGROUND: Early recognition of arteriovenous graft (AVG) dysfunction in hemodialysis (HD) patients followed by prompt corrective procedures reduces AVG thrombosis rates and lengthens access survival. We developed a method to prospectively monitor AVGs that uses an algorithm to calculate venous access pressure (VAP) during HD from the venous drip chamber ...
Crespo Montero R - - 2002
The objectives of this study were to evaluate the degree of blood recirculation (REC) in venous catheters for dual lumen haemodialysis, and its relation to the drop in arterial line pressure and return venous pressure during haemodialysis. A total of 25 catheters were evaluated (15 temporary 15 cm catheters, and ...
Tkachenko B I - - 2002
Dynamics of changes in right-atrial pressure and venous pressure measured in the inferior and superior vena cava at their orifices (central venous pressure) after bolus injection of 20 ml physiological saline or epinephrine (5.0 mg/kg) was studied in acute experiments on cats. The initial pressure in the right atrium was ...
Hayashi K - - 2003
Venous diseases like iliofemoral deep vein thrombosis and valvular dysfunction induce venous hypertension. To know the effects of the hypertension on venous mechanics, blood pressure in the left femoral vein in the rabbit was chronically elevated by the constriction of the left external iliac vein. Wall dimensions and biomechanical properties ...
Arai Junichi - - 2002
BACKGROUND: Peripherally inserted central catheters (PICC) are being increasingly used in neonatal practice. Their use is not without technical difficulty. This report describes the use of continuous pressure monitoring to detect catheter occlusion in critically ill neonates. METHODS: In-line venous pressure of the PICC line was monitored by pressure transducer ...
De Somer F - - 2002
Six different commercially available paediatric venous cannulae, together with a specially constructed cannula, were tested in vitro for their pressure-flow relationship. With the cannulae placed in an open reservoir, flow increased with larger diameters and higher pressures. At a pressure of 30 cm H2O, flows were 219 +/- 20, 285 ...
Chand Deepa H - - 2002
Access failure is a significant cause of morbidity and mortality in hemodialysis patients. Routine monitoring of arteriovenous (AV) fistulas and grafts could increase access longevity. Dynamic venous pressure monitoring is a surveillance test advocated to detect early signs of vascular thrombosis. Venous pressure measurements obtained, per DOQI recommendations, in children ...
Hosoi Yutaka - - 2002
The mechanism of venous pressure decrease during exercise still remains unclear. To explore the components involved with the regulation of ambulatory venous pressure, we reinvestigated the pattern of pressure decrease during tiptoe exercise with a newly developed mathematic model. Seventeen healthy limbs of 16 volunteers (normal group) and 35 limbs ...
Parker J L - - 2002
We compared central venous pressures, measured via a 150 mm triple lumen catheter in the internal jugular vein with simultaneous external jugular venous pressures, measured with a 5 mm cannula in the external jugular vein, in 24 patients undergoing major surgery. Patients were mechanically ventilated in the supine position. Six ...
Almany Daniel K - - 2002
Vacuum-assisted venous drainage (VAVD) is a technique used to increase venous return during cardiopulmonary bypass (CPB). However, VAVD has created some new safety concerns. One potential problem is the pressurization of the venous reservoir in the event of vacuum failure. To prevent this overpressurization, a positive pressure release valve (PPRV) ...
< 2 3 4 5 6 7 8 9 10 11 12 >