Search Results
Results 601 - 650 of 1276
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Sweeney T E - - 1995
We have addressed the hypothesis that varicocele-related infertility is caused in part by a pressure-induced disturbance of testicular convective transport that upsets the testicular hormonal environment and thus impairs spermatogenesis. The left testis of the hamster [pentobarbital sodium (Nembutal), 70 mg/kg ip] was prepared for microcirculatory observations. Testicular venous pressure ...
Chong H H - - 1995
Pericardial effusions may be present in a variety of clinical situations, often presenting challenging clinical diagnostic and therapeutic problems. Although several imaging modalities are available, ECHO has become the diagnostic method of choice due to its portability and wide availability. CT and MRI may also be employed and may be ...
Corboz M - - 1995
We performed pulmonary venous occlusions in order to check the validity of the pulmonary capillary pressure measurements obtained using pulmonary arterial occlusion in the intact animal. The venous and arterial postocclusion pressure profiles were recorded using balloon catheters introduced, respectively, into a left lower lobe vein and into a right ...
Shrier I - - 1995
Compartment syndrome is a condition in which an increase in intramuscular pressure decreases blood flow to skeletal muscle. According to the Starling resistor (i.e., vascular waterfall) model of blood flow, the decrease in flow could occur through an increase in arterial resistance (Rart) or an increase in the critical closing ...
Reda Z - - 1995
We evaluated the effect of elevated airway pressure on the validity of intravascular pressure obtained in the distal inferior vena cava (IVC) as a measure of central venous pressure (CVP) in a group of children receiving mechanical ventilation. The IVC pressure correlated well with CVP in the patients without abdominal ...
Bridges N D - - 1995
OBJECTIVES: Our objective was to determine whether catheterization data obtained after a fenestrated Fontan operation influenced patient management or predicted functional status. BACKGROUND: Cardiac catheterization after a fenestrated Fontan operation is undertaken to identify residual lesions and to observe the patient's response to test occlusion of the baffle fenestration. METHODS: ...
Negl?n P - - 1995
OBJECTIVES: The role of compliance changes in the patho-physiology of venous disease is not well known mainly because of difficulty to measure compliance of veins in situ. This study suggests a method to determine the calf pressure/volume relationship by utilizing venous occlusion plethysmography combined with dorsal vein pressure. DESIGN: Comparison ...
Robotham JL - - 1995
It is generally assumed that inspiration will enhance both superior and inferior vena cava (SVC and IVC) blood flows due to the decrease in right atrial pressure produced by the fall in intrathoracic pressure. However, inspiration can also increase abdominal pressure due to the descent of the diaphragm. Using a ...
Negl?n P - - 1995
OBJECTIVE: In addition to degree of outflow obstruction and reflux and poor calf muscle pump function, vein wall compliance changes are important in understanding pathophysiology of venous disease. This study compares the pressure/volume relationship in post-thrombotic and healthy legs. EXPERIMENTAL DESIGN: Prospective and comparative study. SETTING: Vascular laboratory. PARTICIPANTS: Investigations ...
Tsutamoto T - - 1995
Hemodynamic tolerance has been observed within several hours of continuous infusion of nitroglycerin (NTG). We examined the hemodynamic parameters as well as femoral arterial and venous cyclic guanosine monophosphate (cGMP) concentrations during intravenous infusion of NTG or nicorandil, a nitrate and potassium channel opener, in patients with congestive heart failure. ...
Campbell S L - - 1995
Chylothorax was associated with constrictive pericarditis in a 6-year-old mixed-breed dog. Clinical signs included hepatomegaly, bilateral jugular pulses, muffled heart sounds, and dyspnea. Pleural effusion was identified on thoracic radiographs. Thoracentesis yielded 3 L of chylous effusion, confirmed by the cholesterol/triglyceride ratio (0.14). Echocardiography revealed a thickened pericardium, with numerous ...
Mahy I R - - 1995
1. The relationship between capillary pressure and venous pressure was investigated during incremental venous pressure elevation in seven healthy volunteers. Pressure was measured simultaneously at the apex of finger nailfold capillaries and in the dorsal vein of the ipsilateral hand. Elevation of venous pressure was accomplished by inflation of a ...
Butler B D - - 1995
Venous gas embolism (VGE) is reported with decompression to a decreased ambient pressure. With severe decompression, or in cases where an intracardiac septal defect (patent foramen ovale) exists, the venous bubbles can become arterialized and cause neurological decompression illness. Incidence rates of patent foramen ovale in the general population range ...
Litmanovitch M - - 1995
A prospective study was conducted to compare simultaneous intrathoracic and intra-abdominal central venous pressures in 10 critically ill, ventilated paediatric intensive care patients. Central venous pressures were measured using the water column technique over a 6 h study period. There was excellent correlation between intrathoracic and intra-abdominal vena caval pressure ...
Jónsson F - - 1995
Indices of fluid balance were evaluated during and after aortic surgery in 16 consecutive patients. Thoracic electrical impedance (TI), heart rate (HR), central venous (CVP), pulmonary artery mean (PAMP), pulmonary wedge (PWP) and mean arterial (MAP) pressure as well as fourteen arterial and venous blood gas variables were followed. Consistent ...
Hatzichristou D G - - 1995
A pharmaco-cavernosometry based clinical study was designed to define hemodynamic parameters consistent with complete trabecular smooth muscle relaxation, establish a methodology for overcoming incomplete trabecular smooth muscle relaxation, and determine under controlled conditions the contribution of venous outflow and arterial inflow to the steady-state equilibrium intracavernous pressure. Flow-pressure relationships were ...
Beppu T - - 1995
A pump control system using a microcomputer for cardiopulmonary bypass has been developed. The parameters monitored by the computer are central venous pressure, aortic pressure, blood volume in a reservoir, and collapsing of a small vinyl bag in a venous withdrawal tube. Both pumps in the arterial infusion and the ...
Choudhury D - - 1995
We analyzed the anatomic features of both grafts and fistulas and correlated these features with access function. We also attempted to determine venous pressures predicting access dysfunction (critical venous pressures) at various blood flow rates (BFRs). Therefore, accesses of 46 chronic hemodialysis patients were studied by venography in a prospective ...
Criado E - - 1995
We conducted this study to investigate the physiologic variations in venous valvular function and calf muscle pump function that occur in normal limbs after prolonged stationary standing. Twenty-two limbs from 11 healthy volunteers were studied after a brief period of activity and after 4 to 6 hours of stationary standing. ...
Louisy F - - 1995
Exposure to actual or simulated microgravity is known to result in changes in lower limb venous compliance or distensibility which may play a role in post-bedrest or postflight orthostatic intolerance. Venous deconditioning has only been described in terms of changes in vascular compliance or distensibility. But a complete understanding of ...
Saner H E - - 1995
Ten patients with isolated right atrial tamponade complicating open heart surgery were identified over a 3.5-year period at three institutions. Clinical manifestations varied but were typically those of decreased perfusion with elevated central venous pressure. Hemodynamically these patients had systemic hypotension and tachycardia with elevated central venous pressure but without ...
Louie E K - - 1995
The effect of acute pericardial tamponade on pulmonary venous return was assessed by transesophageal pulsed Doppler echocardiography. In 14 open-chest anesthetized dogs peak pulmonary venous flow velocities in systole (VJ) and in diastole (VK) were measured during apnea and atrial pacing while acute tamponade was induced by intrapericardial instillation of ...
Fink B - - 1995
The effects of ITF 296 on venous tone, estimated as changes in total effective vascular compliance (TEVC), were investigated in the anesthetized, spontaneously breathing dog under autonomic blockade. TEVC was calculated from the correlation between the observed changes in central venous pressure (CVP) and the experimentally induced changes in blood ...
Watenpaugh D E - - 1995
Elevated calf compliance may contribute to orthostatic intolerance following space flight and bed rest. Calf venous compliance is measured conventionally with venous occulusion plethysmography in supine subjects. With this well-established technique, subjects undergo inflation of a pressure cuff around the thigh just above the knee, which increases calf venous pressure. ...
Hopman M T - - 1994
The purpose of this study was to examine the properties of the venous vascular system in the lower extremities of individuals with long-standing paraplegia (PP). The venous volume variations (VVV), the venous capacity (VC), the venous emptying rate (VER) and the venous flow resistance (VFR) were measured in the left ...
Den Hartog E A - - 1994
In the intact circulation, mean systemic filling pressure (Psf) is determined by applying a series of inspiratory pause procedures (IPPs) and using Guyton's equation of venous return (Qv) and central venous pressure (Pcv): Qv = a - b x Pcv. During an IPP series, different tidal volumes are applied to ...
Mellander S - - 1994
1. The controversial problem concerning the unusual haemodynamics of the deranged circulation during increased hydrostatic tissue pressure (PT) was elucidated by detailed studies of arterial, capillary and venous functions in cat skeletal muscle exposed to graded experimental changes of PT over a wide range. 2. The results indicated that the ...
Doenicke A - - 1994
The unphysiologic osmolality of commercial preparations of etomidate dissolved in propylene glycol has limited its use as a drug to induce anesthesia. We wanted to determine whether hydroxypropyl-beta-cyclodextrin (HPCD) is a more suitable solvent than propylene glycol by comparing pharmacokinetics, pharmacodynamics, and side effects of etomidate preparations in each solvent. ...
Asgeirsson B - - 1994
OBJECTIVE: To assess local haemodynamic effects of raised tissue pressure per se and of arterial and venous pressure variations during raised tissue pressure, and to evaluate the vascular waterfall phenomenon. DESIGN: An isolated pump-perfused sympathectomised cat skeletal muscle enclosed in a plethysmograph. INTERVENTIONS: Hydrostatic capillary pressure (Pc), tissue volume alterations ...
Beaumont P E - - 1994
PURPOSE: This is the first report of the monitoring of the clinical progress of a central retinal vein occlusion by measuring the retinal venous collapse pressure using ophthalmodynamometry. METHOD: A 38-year-old woman with a nonischaemic central retinal vein occlusion received systemic prednisone. The dose of prednisone was increased and decreased ...
Alimi Y S - - 1994
Little data are available concerning the relation between the muscular pumping mechanism and the variation of superficial and deep venous pressure during normal action of the calf pump; therefore we undertook this study to determine the pressure values in three compartments of the calf and in the deep and the ...
Ilkiw J E - - 1994
Cardiovascular effects of high dose opioid together with low dose inhalant were compared with inhalant alone to determine whether opioid/inhalant techniques were less depressant on the cardiovascular system. The effects of positive pressure ventilation and increasing heart rate to a more physiological level were also studied. Cardiovascular measurements recorded during ...
Suzuki N - - 1994
The possible venous endothelial toxicity of 0.5% 2-chloroprocaine without additives in intravenous regional anaesthesia (IVRA) was evaluated in rabbits. After exsanguination of a hind limb with an Esmarch's bandage a neonatal blood pressure cuff around the thigh was inflated (250 mmHg). For IVRA 4 ml of either plain 0.5% 2-chloroprocaine ...
Ferguson G T - - 1994
Transdiaphragmatic pressures generated by phrenic nerve twitches have been proposed as a means to assess diaphragmatic function and central drive, but their validity and reliability have not been determined. We evaluated diaphragmatic twitch and twitch occlusion measurements in a rabbit model of diaphragmatic contractile dysfunction and diaphragmatic fatigue to determine ...
Aellig W H - - 1994
1. Venous resistance contributes very little to total peripheral resistance; more than half of the total blood volume, however, is contained in the extrathoracic veins. Owing to marked differences between venous and arterial anatomy and physiology, studies on veins and arteries usually require different methodological approaches. Whereas for arteries the ...
O'Malley M K - - 1994
OBJECTIVE: To assess the infection potential of not routinely changing invasive monitoring kits and associated plasticware. DESIGN: A prospective, observational study of microbiological contamination of a cohort of pressure monitoring infusion systems. SETTING: Adult intensive care units in a university tertiary care center. PATIENTS: Patients who had invasively monitored arterial, ...
Heyman F - - 1994
Particularly in humans, systemic veins are often exposed to extensive changes in transmural pressure at altered body positions, when centrally conveyed constrictor reflexes provide compensation to maintain a proper venous return. The present aim was to explore whether also purely local mechanisms, of e.g. myogenic and/or axon reflex nature and ...
Markel A - - 1994
OBJECTIVE: This study was designed to test the results of Valsalva's maneuver and limb compression against the standing-cuff inflation-deflation method for the detection of venous valvular reflux. DESIGN: The study was conducted in 67 patients (134 extremities) who had an episode of deep vein thrombosis. An ultrasonic duplex scanner was ...
Emerson R J - - 1994
BACKGROUND: Indirect/noninvasive blood pressure, heart rate and central venous pressure are frequently monitored hemodynamic parameters in postoperative cardiac surgery patients. No previous studies have explored the effect of lateral position on these variables in this population. OBJECTIVES: To determine differences in (1) blood pressure, central venous pressure, or heart rate ...
Jilma B - - 1994
Based on previous experimental and epidemiologic findings, we hypothesized that 17 beta-estradiol (E2) could decrease the alpha-adrenergic responsiveness in venous smooth muscle cells (VSMC), thereby decreasing venous tone and contributing to the pathogenesis of varicose veins. To test this hypothesis, the effect of an acute increase in E2 serum concentrations ...
Norbash A M - - 1994
PURPOSE: To determine whether there is a physiologic explanation for the predisposition of patients with certain angiographic characteristics to symptoms of hemorrhage and steal. METHODS: Superselective transcatheter feeding arterial pressure and mean arterial pressure measurements were obtained before embolotherapy in 32 patients with cerebral arteriovenous malformations. Pressures were correlated with ...
Murdoch I A - - 1994
We compared central venous pressure measurements from three sites, superior vena cava, inferior vena cava and right atrium, in 12 children undergoing cardiac catheterization whilst on assisted ventilation. There was no significant difference between the mean pressures in the superior vena cava and the inferior vena cava. Furthermore, there was ...
Williams P M - - 1994
Light reflection rheography (LRR) has been developed as a simple, quick and non-invasive test of venous function which reproduces the haemodynamic parameters of venous pressure measurements by recording changes in dermal blood content of the lower limb during exercise. It uses the same principles as photoplethysmography (PPG) but is simpler ...
Van Stone J C - - 1994
Stenosis of the outflow segment of hemodialysis access grafts frequently leads to thrombosis and loss of the access. Previous studies have shown that early detection and correction of the stenosis can prevent graft failure. The purpose of the present study was to compare four methods of detecting outflow segment stenosis: ...
Knott-Craig C J - - 1994
Central venous pressure (CVP) and left atrial pressure (LAP) were monitored continuously for the first 72 hours postoperatively in 32 patients who underwent a Fontan operation in whom preoperative measurements of the pulmonary artery index were available. Integrated mean values were generated for each patient for the following time frames: ...
Jacobson J D - - 1994
Cardiorespiratory effects of an IV administered bolus of ketamine (7.5 mg/kg of body weight) and midazolam (0.375 mg/kg) followed by IV infusion of ketamine (200 micrograms/kg/min) and midazolam (10 micrograms/kg/min) for 60 minutes was determined in 6 dogs. Ketamine-midazolam combination was administered to dogs on 3 occasions to determine effects ...
Marchiori G E - - 1994
Fourteen normal subjects (18-42 y) were studied using venous occlusion plethysmography to investigate the characteristics and reproducibility of the forearm vasoconstrictor response following a prolonged venous occlusion stimulus. Upon release of the stimulus, a transient vasodilation is followed by a vasoconstriction. As the stimulus of venous occlusion pressure increased (40, ...
Amoore J N - - 1994
OBJECTIVE: Venous collapse limits systemic venous return, but its effects on beat to beat respiratory venous return variations are less well known. The aim of this study was to investigate the effects of venous collapse on respiratory variations in venous return. METHODS: A model of venous collapse which included both ...
Rölleke T - - 1994
We studied the effects of hANP 99-126 on capillary filtration and venous compliance in both the calf (mainly skeletal muscle) and foot (mainly skin) of humans. Six healthy mean received ANP (intravenous injection of 25 micrograms followed by continuous infusion of 0.1 microgram.kg-1.min-1) for 30 min. Another six men served ...
Wendling W - - 1994
We examined the effects of Valsalva's manoeuvre and its four phase on heart rate, central venous pressure (CVP), mean arterial pressure (MAP), cerebral perfusion pressure (CPP), and laser Doppler cerebellar cortical blood flow (CBF). Brief Valsalva manoeuvres increased CVP and markedly decreased MAP. Cerebral perfusion pressure significantly (P < or ...
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