Search Results
Results 301 - 350 of 1273
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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) ...
Bergan John J - - 2002
Lower extremity venous insufficiency is a highly prevalent condition. Now it is understood that telangiectasias, reticular varicosities, and true varicose veins are physiologically similar and etiologically identical. The four main influences causing these abnormalities are heredity, female sex, gravitational hydrostatic forces, and hemodynamic muscular compartment pressure. There are clear indications ...
Corpataux Jean-Marc - - 2002
BACKGROUND: The aim of the study was to determine which, and to what extent, haemodynamic parameters contribute to the remodelling of the venous limb of the Brescia-Cimino haemodialysis access. METHODS: The dimensions of the radial artery and the venous limb of the haemodialysis access were measured by an echo-tracking technique. ...
Mehta Hitesh K - - 2002
The blood flow rate delivered by the dialysis machine (d-BFR) may not be accurately reflected by the blood flow rate set on the machine (sm-BFR). High negative arterial pressure may lead to deformity of the blood pump-segment tubing, resulting in a lower stroke volume and d-BFR. The Hagen-Poiseuille law predicts ...
Dember Laura M - - 2002
BACKGROUND: Static venous pressure elevation has been shown to have both high sensitivity and high specificity for hemodialysis arteriovenous (AV) graft venous anastomosis stenosis. However, it is not known how well static venous pressure elevation predicts subsequent AV graft thrombosis. METHODS: Monthly static venous pressure measurements were made during two ...
Koehler Nelson R - - 2002
The objective of the present investigation was to study the effects of a 60-s interval of venous congestion between two noninvasive measurements of arterial blood pressure (ABP) on the fluctuation of ABP, assessed by the standard deviation of the differences between two readings. ABP was measured in 345 successive patients, ...
Kleinekofort W - - 2002
Vascular access stenosis and thrombosis is one of the key problems for hemodialysis patients. Prospective monitoring of static venous dialysis pressures can be applied to detect outflow stenoses in a vascular access. However, the location of stenoses within the access may influence the diagnostic value of venous pressure measurements. Whereas ...
Neglén Peter - - 2002
The purpose of this study was the comparison of intravascular ultrasound scanning (IVUS) with transfemoral venography in the assessment of chronic iliac vein obstruction. IVUS and standard, single-plane, transfemoral venography were performed in 304 consecutive limbs during balloon dilation and stenting of an obstructed iliac venous segment. The appearance of ...
Blumberg Mark S - - 2002
When exposed to extreme cold or injected with the alpha(2)-adrenoceptor agonist, clonidine, infant rats emit ultrasonic vocalizations (USVs). Based upon the cardiovascular changes that accompany these two manipulations, especially decreased venous return, it was hypothesized that USVs are the acoustic by-product of the abdominal compression reaction (ACR), a maneuver that ...
Tuncel Meryem - - 2002
BACKGROUND: Although the sympathomimetic actions and cardiovascular complications of cocaine are ascribed to inhibition of norepinephrine (NE) reuptake, this hypothesis has not been tested in humans. We asked (a) whether cocaine can inhibit NE reuptake in the human peripheral circulation and (b) whether the NE-mediated peripheral vasoconstriction is the main ...
Schaller Carlo - - 2002
Recent experiments showed an upward shift of the lower limit of autoregulation (AR) following photochemical occlusion of cortical veins in the rat. The goal of the present study was to prove the hypothesis that occlusion of cortical veins will be associated with impairment of the upper limit of autoregulation as ...
Fu Qi - - 2002
The present study was performed to test the hypothesis that calf venous capacitance would be reduced by mild gravitational stress through a vasomotor reflex in humans, and this response could be diminished with advancing age. Nine young (31 +/- 1 years, mean +/- SE) and 9 elderly (69 +/- 1 ...
Chieveley-Williams Sarah - - 2002
STUDY OBJECTIVES: To determine whether the change in bladder pressure (Pblad) and central venous pressure (Pcvp) may reflect the changes in esophageal pressure (Pes) and gastric pressure (Pgas) when inspiratory pressure support (IPS) is altered. DESIGN: Prospective clinical study. SETTING: The ICUs of a teaching hospital. PATIENTS: Ten patients currently ...
DeSanctis M T - - 2002
Noninvasive macro- and microcirculatory tests provide quantitative information that offers answers to most questions posed in venous diseases. Duplex scanning is used to assess the macrocirculation, and microcirculatory methods are used to assess and quantify venous microangiopathy. Laser Doppler flowmetry is used to assess perfusion. Transcutaneous Po(2) and Pco(2) measurements ...
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