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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 ...
Jorgensen J O - - 1994
To assess the impact of raised intra-abdominal pressure associated with laparoscopy on venous return, we have used an animal model (pig) to study the effect of progressive increases in insufflation pressure on femoral venous blood outflow. As a second variable, the effect on flow of the reverse Trendelenburg position was ...
Miyasaka Y - - 1994
BACKGROUND: Recent radiological studies have shown that arteriovenous malformations with impaired venous drainage may be susceptible to hemorrhage. To evaluate this hypothesis using a hemodynamic approach, we measured intravascular pressure during surgery in three patients with arteriovenous malformation. SUMMARY OF REPORT: In three patients we measured intravascular pressures in the ...
Chait H I - - 1994
OBJECTIVE: To compare "central venous pressure" in pediatric patients in a clinical setting as measured from catheters in the infrahepatic inferior vena cava and the right atrium. DESIGN: Prospective, unblinded study. SETTING: Cardiothoracic intensive care unit of a tertiary care university hospital. PATIENTS: Thirty-three pediatric cardiac surgical patients, 2 days ...
Katz M L - - 1994
This study was designed to evaluate changes in venous hemodynamics that occur in normal, symptom-free male and female volunteers, as a consequence of daily activity. Each leg of 25 symptom-free volunteers was prospectively studied twice in the early morning and twice in the late afternoon on 2 days. Air plethysmography ...
Hildebrandt W - - 1994
This study evaluated the postural vascular adjustment in the human forearm which may be responsible for the recent observation that transcapillary fluid balance is maintained above the level of the heart while blood flow decreases in a linear fashion. In this study further evidence was provided that a posturally graded ...
Pascoe P J - - 1994
Cardiopulmonary effects of halothane administration were studied in hypovolemic dogs. Baseline cardiopulmonary data were recorded from conscious dogs after instrumentation. Hypovolemia was induced by withdrawal of blood from dogs until mean arterial pressure of 60 mm of Hg was achieved. Blood pressure was maintained at 60 mm of Hg for ...
Shiramoto M - - 1994
Calcium antagonists are potent dilators of resistance vessels but do not dilate capacitance vessels. CD832 is a novel dihydropyridine calcium antagonist which has a nitrate moiety in its chemical structure. The authors examined the effects of CD832 on venous capacitance in anesthetized rats. Venous capacitance was assessed by measuring mean ...
Deschamps A - - 1994
To determine the effect of neuropeptide Y (NPY) on regional vascular capacitances, we measured the regional blood volume (Vb), unstressed volume (V0), blood flow distribution, venous compliance (Cv), venous resistance (Rv), and the time constant of venous drainage (tau v) in the splanchnic and extrasplanchnic circulation of 13 dogs anesthetized ...
Hassler W - - 1994
During ten operations for spinal dural arterio-venous fistulas (AVF), intraoperative measurement of flow velocity and intravascular pressure was performed. Flow velocities were recorded using a miniaturized Doppler probe. Intravascular pressure changes in the draining veins before and after AVF removal was measured with small needles. Varying the pCO2 between 20 ...
Lung M A - - 1993
It is known that parasympathetic nerve stimulation elevates venous pressure in the dog submandibular gland, and that the venous pressure wave is transformed to that of the arterial pulse. The vascular arrangements and histological characteristics of the dog submandibular gland were therefore examined to establish which anatomical structures are responsible ...
Taylor A W - - 1993
The exact anatomy of the central retinal vein as it exits the eye is unknown. In this study serial sections of the central retinal vein and artery in the anterior optic nerve from six globes (five from cornea donors and one exenteration specimen) were examined by image analysis and three-dimensional ...
Belcaro G V - - 1993
Chronic venous hypertension produces microangiopathy which often progresses to ulceration. It has been recently observed that intermittent sequential compression (ISC) increases the rate of healing of venous ulcers. The aim of this study was to investigate the effect of this form of therapy on the microcirculation in limbs with venous ...
Rose W C - - 1993
Hemodynamic properties of the systemic vasculature were measured in eight anesthetized dogs using two-port impedance analysis. Blood pressures and flows were measured at the aortic root and the caval-atrial junction. Impedances were computed from 0.05 to 20 Hz to characterize the systemic vasculature. Pseudorandom variations in flow were produced with ...
Kiev J - - 1993
We studied 27 patients with venographically documented bilateral subclavian vein occlusion thrombosis after the use of dual lumen hemodialysis catheters. Immediate venous access was severely limited because all patients had previously had multiple access failures. The rate of venous pressure rise between hemodialysis treatments is inconsistent in suggesting imminent thrombosis ...
van Bemmelen P S - - 1993
Duplex ultrasonography with distal cuff deflation was used to determine the presence and size of incompetent veins and compare the results with those of air plethysmography in patients with chronic venous insufficiency. Thirty-two legs underwent a detailed study with both modalities. Sixteen legs had venous ulceration, six had stasis dermatitis, ...
Lee T S - - 1993
The insertion of a central venous pressure (CVP) catheter has been known to be associated with a variety of complications. Among these, isolated hydromediastinum is relatively rare. We recently encountered a patient who developed hydromediastinum due to extravascular penetration of a CVP line inserted via the right external jugular vein. ...
Palmer M - - 1993
Argon-enhanced coagulation (AEC) is a method for operative coagulation of tissues that utilizes a jet of argon gas encompassing an electrofulguration arc. Concern has been raised that the argon jet may produce harmful venous gas embolization. Two questions were addressed by this study. First, does AEC result in generation of ...
Arcaya J - - 1993
The natural history of symptomatic adult type I Arnold-Chiari (ACM1) malformation is variable. Patients with this condition frequently develop corticospinal and sensory deficits, together with cerebellar signs and lower cranial nerve palsies in various combinations. In the present report we describe a patient with ACM1 in whom sleep apnea together ...
Lew T W - - 1993
To confirm the incidence of venous air embolism (VAE), we simultaneously monitored expired nitrogen concentration (FEN2) and precordial Doppler in 30 patients undergoing cesarean delivery during general anesthesia. Patients were randomized into two groups and the effect of a 10 degrees reverse Trendelenburg tilt versus the horizontal position was evaluated. ...
Aita D J - - 1993
Four-compartment fasciotomies used to relieve abnormally high compartment pressures necessitate interruption of the ensheathing fascial membrane. In the calf, this is considered an important component in maintaining a viable musculovenous pump and preventing venous hypertension, a leading cause of venous insufficiency. Through postoperative physical examination and photoplethysmography evaluation of 47 ...
Ferguson J - - 1993
Interface pressures beneath six types of collar in volunteers were measured. Under certain types of collar mean interface pressures of more than 10 mmHg were obtained, with several individual readings around 30 mmHg. By causing jugular venous obstruction a similar rise in intracranial pressure may be produced inadvertently. The mechanisms ...
Payne S P - - 1993
Air plethysmography was compared with clinical assessment, ambulatory venous pressure measurement and duplex ultrasonography in 103 unselected limbs with venous disease and ten normal control limbs without such disease. Measurements of venous function obtained by air plethysmography showed considerable overlap between groups of limbs classified on the basis of clinical ...
Gabrielsen A - - 1993
Thermoneutral (34.9 degrees C) water immersion (WI) was conducted with 12 upright seated normal males at four consecutive water levels (5-10 min each): knee (reference), xiphoid process, fourth intercostal space, and sternoclavicular notch. Thereafter, water was let out of the tank and the experiment was repeated from the neck to ...
Liang J - - 1993
The purpose of this study was to examine the effects of prostaglandin E1 (PGE1) on venous capacitance during controlled hypotension. Trinitroglycerin (TNG) was used as a control agent. In rats anesthetized with ketamine, mean arterial pressure was lowered to 70 mmHg and subsequently 50 mmHg by intravenous infusion of PGE1 ...
Tollan A - - 1993
Effects of ovarian stimulation for in vitro fertilization on blood pressure and plasma catecholamine levels were studied in 10 women. The examinations were carried out before hormonal treatment with human menopausal gonadotropin (day three of the menstrual cycle, mean serum oestradiol concentration 0.2 nmol l-1, and on the day after ...
Shi X - - 1993
Fourteen healthy young men were exposed to progressive increases in lower body positive pressure (LBPP) from 0 to 40 Torr in the supine position. Central venous pressure (CVP) increased 1.09 mmHg (P < 0.05) at 5 Torr LBPP. Between 20 and 40 Torr LBPP CVP increased 0.85 mmHg, resulting in ...
Kitoh T - - 1993
To study the contribution of tissue components to the mechanical properties of veins, pressure-volume relationships were obtained with the cylindrical segments of isolated dog external jugular veins at several levels of longitudinal extension. At each length, the transmural pressure of the segment was raised up to 20 cmH2O and then ...
Leon M - - 1993
The aim of this study was to establish the long-term effect of graduated elastic compression on venous elasticity in patients with superficial or deep venous disease and to determine the possible relationship between elasticity and the duration of the disease. The elastic modulus of 29 patients, 19 with superficial vein ...
Nakhostine M - - 1993
Pressures in the tibialis anterior muscle were recorded at rest and during exercise with transducer-tipped catheters in 12 volunteers while they were supine or standing. The recordings were repeated with venous stasis created by an inflated tourniquet cuff on the thigh. Catheters were placed at 3 different sites in the ...
Gamble J - - 1993
1. We have used non-invasive mercury in a silastic strain gauge system to assess the effect of pressure step size, on the time course of the rapid volume response (RVR) to occlusion pressure. We also obtained values for hydraulic conductance (Kf), isovolumetric venous pressure (Pvi) and venous pressure (Pv) in ...
Beebe D S - - 1993
Intraoperative venous stasis may increase the risk for perioperative deep vein thrombosis and pulmonary embolism. To determine if abdominal insufflation during laparoscopic cholecystectomy causes venous stasis, eight patients undergoing this procedure had their left common femoral veins examined by a duplex scanner before and after abdominal insufflation; the veins then ...
Langham B T - - 1993
We have compared the cardiovascular response to insertion of an 18-gauge venous cannula in 40 healthy patients. In 20 of the patients, cannulation was preceded by infiltration of local anaesthetic. Both rate-pressure product and mean arterial pressure increased significantly (P < 0.01) compared with baseline when no local infiltration was ...
Fukutome T - - 1993
A newly designed 4 FG double-lumen catheter with the second port located either 5 or 7 cm proximal to the tip was tested in five children undergoing open heart surgery. The catheter was inserted percutaneously and initially positioned in the superior vena cava, right atrium or inferior vena cava. During ...
Doig J C - - 1993
A 62-year-old lady who was receiving corticosteroids for rheumatoid arthritis was admitted suffering from dehydration due to salmonella enteritis. Despite rehydration and appropriate chemotherapy she remained unwell and developed hypotension and elevation of her jugular venous pressure. Echocardiography and subsequent aspiration demonstrated a purulent pericardial effusion from which S typhimurium ...
Hopf H B - - 1993
In healthy humans, the increase in arterial blood pressure seen in patients with autonomic dysfunction in response to exogenous vasopressin (AVP) is abolished. We tested the hypothesis that redistribution of blood from the intra- to the extrathoracic vascular compartment might contribute to this buffer response. Regional distribution of 99mTc labeled ...
Manyari D E - - 1993
BACKGROUND: No method exists to assess human splanchnic venous function, the most important region in terms of vascular capacity. METHODS AND RESULTS: We studied 25 stable patients without heart failure or hypertension to develop a method to assess the splanchnic venous volume-pressure (V-P) relation and to determine the effect of ...
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