Search Results
Results 501 - 550 of 1271
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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 ...
Bojić L - - 1997
The aim of this study was the assessment of physiological venous reflexes in open angle glaucoma. The study was carried out by a controlled clinical experiment. The experimental group consisted of 17 glaucoma patients with controlled intraocular pressure. The control group consisted of 15 healthy volunteers. The assessment of venous ...
Dormandy A - - 1997
The currently favoured hypothesis for the link between the raised venous pressure of chronic venous insufficiency and venous ulceration is based on the intermittent inappropriate activation of white blood cells. The damage initiated by the oxidative burst of the leucocyte leads to endothelial dysfunction, interstitial oedema, microthrombi and long-term microcirculatory ...
van Kuijk W H - - 1996
It has been suggested that hemodynamic instability and impaired vascular reactivity during combined ultrafiltration-hemodialysis are related to bioincompatibility factors such as dialysate-derived contaminants or the dialyzer. The study presented here investigated whether vascular reactivity could be improved by the use of sterile dialysate. Forearm vascular resistance and venous tone (measured ...
Dinwiddie L C - - 1996
OBJECTIVE: To compare two methods, venous dialysis pressure (VDP) and intra-access static flow pressure (VPO), for the prospective identification of venous stenoses in high-risk PTFE grafts. DESIGN: Comparative. SAMPLE/SETTING: Twenty patients with upper extremity loop grafts in an outpatient chronic hemodialysis population. METHODS: VDP and VPO were measured for three ...
Hakim T S - - 1996
The arterial, double and venous occlusions are used to partition pulmonary vascular resistance into four segments. In this study, we tested whether the same can be accomplished from one double occlusion. In an isolated canine lung left lower lobe perfused with blood (flow rate = 500 mL.min-1), the pulmonary arterial ...
Saharay M - - 1996
Leukocyte trapping and activation in the microcirculation of the legs may play an important role in causing skin damage in venous disease. Leukocyte emigration from the microcirculation and subsequent locomotion in response to venous hypertension was studied in a group of 12 normal volunteers using a "skin window" technique. Two ...
Menawat S S - - 1996
To study the hemodynamic effects of an arteriovenous fistula (AVF) used as an adjunct to venous reconstructions and to determine the optimal size for such a fistula. A model of limb circulation with an AVF (in vitro system) was constructed with silicon elastic tubes and 40% glycerin solution as the ...
Deng X - - 1996
Excessive distension of venous grafts due to arterial pressure enhances the convective water transport (filtration flow) through the vessel wall, and thus might affect the infiltration of macromolecules such as lipoproteins. In this paired experimental study, filtration velocities were measured at 100 mm Hg for canine jugular veins with or ...
Spence R K - - 1996
Compression of the lower extremity is the mainstay of therapy in patients who have chronic venous insufficiency. We evaluated the ability of two forms of compression-elastic stockings and an inelastic compression garment-with air plethysmography to determine how well they corrected abnormal deep venous hemodynamics in patients who had class III ...
Tyberg J V - - 1996
We suggest a mechanism by which blood volume changes might explain the hypotension that, after space flight, often accompanies the return to normal gravity. Upon entering microgravity, peripheral veins may collapse and, because of volume redistribution, raise the pressure in the central venous compartment. After some time in space, homeostatic ...
Abu-Yousef M M - - 1996
OBJECTIVE: The purpose of this study was to determine if pulsatile flow in lower limbs as seen on venous Doppler waveforms correlates with increased right atrium pressure. MATERIALS AND METHODS: Of 429 patients who, over a 14-month period, underwent venous Doppler imaging of the lower limb to exclude deep venous ...
Simons P - - 1996
Oedema remains one of the most common causes of hand stiffness. Local venous return is intimately associated with oedema formation and management. To elucidate the underlying mechanisms of venous return, the venous pumping systems in the hand were objectively and quantitatively investigated using Doppler ultrasound, cadaveric dissection and venography. It ...
Veraart J C - - 1996
BACKGROUND: Although medical elastic compression stockings are widely used in venous diseases their effects on the venous system are still largely unclear. OBJECTIVE: To evaluate the pressure of these medical elastic compression stockings on the skin and their edema protective effects. METHODS: On 18 legs the interface pressure of the ...
Nalbantoglu U - - 1996
In this study, peripheral microcirculatory response to arterial and venous cannulation was studied. Eleven Sprague-Dawley rats were evaluated in two groups. Group I was the control group and received no cannulation (N = 6). After cremaster muscle isolation, the following parameters were evaluated at the microcirculatory level: vessel diameters, red ...
Tyberg J V - - 1996
The concept of left ventricular (LV) 'preload' has seemed simple and straightforward. Similarly, the capacitance function of the veins seemed to be defined, in spite of the fact that 'venous return' might be said to be increased in heart failure when it was obvious that cardiac output was substantially decreased. ...
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