BACKGROUND: This study was initiated to find a method of determining the prognosis for possible changes in hemodynamic and respiratory parameters in patients with pneumoperitoneum (PP). METHODS: We devised a model for a pseudopneumoperitoneum (PPP), which is created by encircling the wide pneumochamber on the entire abdomen and inflating it ...

The venoarteriolar response (VAR) of the skin in legs caused by experimental venous hypertension was measured using a new, double-wavelength laser Doppler probe technique (543 nm and 780 nm). This enables the measurement of the laser Doppler flux in the superficial and deep layers of the skin simultaneously. The recordings ...

The dynamic coupling between cardiac pump performance and vascular arterial-venous capacitive and resistive properties was examined analytically and experimentally to determine the feasibility of maintaining systemic and pulmonary circulation, devoid of the right heart. Analysis of the cardiovascular system (excluding neurohumoral factors), used a mathematical representation of the major determinants ...

Venous compliance in the calf of humans and its importance for capacitance function in relation to age were studied with the aid of 22, 44, and 59 mmHg lower body negative pressure (LBNP). Negative pressure transmission to the calf as well as changes in calf volume were studied, and venous ...

To determine whether the venous circuit constitutively produces nitric oxide (NO), we infused the NO synthase inhibitor, NG-nitro-L-arginine methyl ester (L-NAME) into anesthetized and mechanically ventilated pigs and measured venous circuit parameters. We measured cardiac output (Q) by thermodilution and obtained arterial (Part), central venous pressure (in the inferior vena ...

The results of different vascular tests used in the diagnosis of cavernosal arterial insufficiency and cavernosal venous leakage were compared in 168 men, with an average age of 62.9 y to determine which were the most reliable. One hundred and forty-five men had penile arterial insufficiency demonstrated with digital subtraction ...

PURPOSE: To determine whether central venous pressure at the common iliac vein reflects right atrial pressure in adult patients. METHODS: In this prospective, non-blinded study 26 mechanically-ventilated adult patients were studied. Simultaneous pressure readings were obtained from the right atrium (TCVP) and the common iliac vein (ACVP). RESULTS: There was ...

Acute head-down tilt (AHDT, -30 degrees) in humans induces a transient ventilatory augmentation for 1-2 min accompanied by a high venous return. However, the mechanisms underlying this respiratory response remain obscure because of limitations of experiments carried out in human subjects. The present study was undertaken to determine whether AHDT-induced ...

In Part I of this two-part series on cardiovascular assessment, the author described basic components of physical assessment relating to cardiac assessment such as skin color, integrity and hydration, pulses, shortness of breath, edema, and weight changes. In Part II, the intricacies of accurate blood pressure measurement, central venous pressure ...

The aim of the present study was to determine effects of positive end expiratory pressure (PEEP) application on peripheral venous capacitance and relate them to concomitant central hemodynamic disturbances. The venous volume-pressure (V/P) relationships were studied in 6 intact anesthetized pigs to describe the effects of PEEP on systemic venous ...

PURPOSE: A technique to control venous bleeding after retropubic prostatectomy is described. MATERIALS AND METHODS: A man underwent retropubic prostatectomy for an enlarged benign prostate following which hemorrhage occurred. RESULTS: After failure of other more traditional methods of hemostasis, the bleeding was stopped by direct anterior digital rectal pressure. CONCLUSIONS: ...

BACKGROUND: Toborinone (OPC-18790), a phosphodiesterase III inhibitor, enhances cardiac contractility and is an arterial dilator. However, its effects on the venous system have not yet been clearly defined. Because toborinone administration reduces left ventricular (LV) end-diastolic pressure, it is probably also a venodilator. Because of the known arterial effects and ...

OBJECTIVE: To explain why investigations of the measurement of central venous pressure (CVP) usually reveal a discrepancy between the clinician's estimate of CVP from physical diagnosis and supine measurement with a catheter. Data from MEDLINE search, personal files, and bibliographies of textbooks on physical diagnosis and cardiology were used. RESULTS: ...

The purpose of the present work was to study in vivo in rat the consequences of repeated exposures to sustained +Gz centrifugations on the venous pressure and on the venous tone, that one evaluated by measuring the equilibrium pressure of all vessels in the circulation when the flow is null ...

BACKGROUND: Abnormally increased pressure in the anterior compartment of 20 legs in 10 subjects was induced by applying venous stasis of a casted leg and external compression by a cylindrical air splint of the contralateral leg. The effects of increased intramuscular pressure (IMP) on blood perfusion pressure and clinical symptoms ...

OBJECTIVES: To study the effects of limb elevation on abnormally increased intramuscular pressure (IMP) and blood perfusion pressure in the anterior compartment of the leg. DESIGN: An experimental cross-over design. The test leg was elevated and the control leg was kept at heart level. PARTICIPANTS: Eight healthy subjects with a ...

The mediodorsal nucleus of the thalamus (MD) has connections with central autonomic centers involved in cardiovascular control and undergoes severe degeneration in fatal familial insomnia, a human disease characterized by progressive dysautonomia. Microinjections of the GABAA antagonist bicuculline methiodide (BMI) into the medial and central portion of the MD lead ...

To assess the contribution of the arterial and venous systems in the hemodynamic changes of normal pregnancy, we studied blood flow, vascular resistance, venous tone, and the viscoelastic properties ("creep") of the upper and lower limbs (using plethysmography), aortic distensibility (using pulse wave velocity measurements), and cardiac dimensions (using echocardiography) ...

Aging influences pulmonary venous flow and mitral inflow velocities. The duration of pulmonary venous atrial reversal flow exceeds that of the mitral inflow A wave in patients with left ventricular end-diastolic pressures greater than 15 mm Hg. The objective of this study was to investigate the effect of age on ...

STUDY OBJECTIVE. To determine the effect of different positional degrees on hemodynamics, especially central venous pressure and intraocular pressure, and a possible interrelationship, during laparoscopic surgery. SETTING. University teaching hospital (Canadian Task Force classification II-1). PATIENTS: Seven women undergoing elective gynecologic laparoscopy. INTERVENTIONS: The women were monitored for heart rate, ...

Felodipine is a second-generation dihydropyridine calcium antagonist used to treat mild to moderate arterial hypertension. The authors used venous occlusion plethysmography to study the effect of this drug on lower limb arterial inflow and venous outflow in 10 at rest patients with mild essential hypertension. They also sought correlations between ...

The significance of the sympathetic nervous system (SNS) in regulating peripheral vascular resistance and cardiac function in fish has been well established, whereas its effect on venous function in vivo is unknown. Two protocols were employed in the present study to evaluate SNS effects on the venous system in intact, ...

To study the influence of venous hypertension, which develops in lower limbs under pneumoperitoneal pressure, on microcirculation, plethysmographic measurements were performed in patients before and during laparoscopic and traditional (open) cholecystectomy. During laparoscopy, isovolumetric venous pressure (estimate of capillary pressure), and filtration coefficient (estimate of patent capillary surface) decreased, which ...

Complications associated with pulmonary artery catheters (PACs) include interpretation errors, insertion problems, sepsis, thrombosis, and dysrhythmias. Alternatives to the use of PACs include the central venous pressure catheter, measurement of cardiac output by thoracic electrical bioimpedance, gastric tonometry and the measurement of serum lactate level, and the still to be ...

PURPOSE: Foot venous pressure measurement is considered to be useful for assessing lower limb venous insufficiency, because venous hypertension is the main factor predisposing to venous insufficiency. In this study, we investigated the utility of foot venous pressure measurement in the evaluation of venous insufficiency. METHODS: A total of 148 ...

AIMS: Protein losing enteropathy is a serious complication of Fontan surgery. The aim of this study was to investigate gastro-intestinal protein loss in adults with congenital heart disease, both with and without Fontan surgery, and to correlate findings with systemic venous pressure. METHODS AND RESULTS: Forty eight patients were studied. ...

1. We studied human lower limbs to test the hypothesis that the application of small cumulative venous congestion pressure steps is associated with a reduction in precapillary resistance. 2. Strain gauge plethysmography was performed on twenty-one young subjects (22.7 +/- 0.6 years). At each of the small cumulative pressure steps, ...

Arterial and venous plasma catecholamine responses to 15 min of cycling at 60% of maximal oxygen uptake were examined 11 times during exercise and recovery in nine young men. Intra-arterial blood pressure, heart rate and oxygen uptake were recorded continuously. All variables increased significantly during the initial 4 min, after ...

The measurement of intra-access pressure (P[IA]) normalized by mean arterial BP (MAP) helps detect venous outlet stenosis and correlates with access blood flow. However, general use of P(IA)/MAP is limited by time and special equipment costs. Bernoulli's equation relates differences between P(IA) (recorded by an external transducer as PT) and ...

Lower body negative pressure is frequently used to simulate orthostasis. Prior data suggest that venous pooling in abdominal or pelvic regions may have major hemodynamic consequences. Therefore, we developed a simple paradigm for assessing regional contributions to venous pooling during lower body negative pressure. Sixteen healthy men and women underwent ...

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 ...

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 ...

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 ...

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. ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

PURPOSE: 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. METHODS: A linear relationship between venous pressure (measured by echo-guided venous puncture) and diameter (measured ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...