OBJECTIVE: To determine whether peripheral venous pressure (PVP) was correlated with central venous pressure (CVP) when measured by use of different catheter sizes, catheterization sites, and body positions in awake dogs and cats. ANIMALS: 36 dogs and 10 cats. PROCEDURES: Dogs and cats with functional jugular and peripheral venous catheters ...

The hemodynamic significance of the calf perforating veins continues to be the point of controversy. The conception that incompetent perforating veins cause hemodynamic disturbance and are responsible for the formation of leg ulceration has still many adherents prefering perforator surgery, whereas others reject any causal relation between large, incompetent perforators ...

PURPOSE: Using peripheral venous pressure (PVP) instead of central venous pressure (CVP) as a volume monitor decreases patient risks and costs, and is convenient. This study was undertaken to determine if PVP predicts CVP in pediatric patients. METHODS: With ethical approval and informed consent, 30 pediatric patients aged neonate to ...

PURPOSE: To estimate the central retinal vein pressure in patients with ischemic vs nonischemic central retinal vein occlusion (CRVO). DESIGN: Prospective clinical observational comparative study. METHODS: The study included 28 patients with CRVO, either of the ischemic type (n = 7) or the nonischemic type (n = 21). The control ...

OBJECTIVE: The information derived from central venous catheters is underused. We developed an EKG-R synchronization and averaging system to obtained distinct CVP waveforms and analyzed components of these. METHODS: Twenty-five paralyzed surgical patients undergoing CVP monitoring under mechanical ventilation were studied. CVP and EKG signals were analyzed employing our system, ...

Recent studies in humans have suggested sex differences in venous compliance of the lower limb, with lower compliance in women. Capillary fluid filtration could, however, be a confounder in the evaluation of venous compliance. The venous capacitance and capillary filtration response in the calves of 12 women (23.2 +/- 0.5 ...

Contradictory reports on the significance of several hemodynamic phenomena, such as femoral vein incompetence and incompetent calf perforators, impede orientation in venous hemodynamics. Venous pressure difference arising between the popliteal and the posterior tibial vein during the activity of the calf muscle venous pump was reported for the first time ...

INTRODUCTION: Limb venous compliance is a major factor in determining the extent of blood pooling during orthostatic stress. We measured the filling of the calf and of its major veins at different postures and quantified the venous contribution to the total volume shift of the calf. The results were also ...

Synbranchus marmoratus is a facultative air-breathing fish, which uses its buccal cavity as well as its gills for air-breathing. S. marmoratus shows a very pronounced tachycardia when it surfaces to air-breathe. An elevation of heart rate decreases cardiac filling time and therefore may cause a decline in stroke volume (V(S)), ...

AIM: High peripheral resistance and structural alteration in resistance arteries are central phenomena in essential hypertension and have been widely examined by forearm venous occlusion plethysmography; at rest for studying vascular tone, and during reactive hyperaemia for studying vascular structure. This work concerns the influence of venous pressure on hyperaemic ...

BACKGROUND: The effect of pneumoperitoneum on veins of the lower limbs related to the intra-abdominal working pressures during laparoscopic cholecystectomy has not been thoroughly investigated. We tested the hypothesis that working pressures do not affect the venous haemodynamics in the lower limbs. METHODS: The cross-sectional area and peak flow rates ...

BACKGROUND: Accurate assessment and monitoring of the cardiocirculatory function is essential during major pediatric and pediatric cardiac surgery. Invasive monitoring of cardiac output and oxygen delivery (DO(2)) is expensive and sometimes associated with adverse events. Measurement of central venous oxygen saturation (ScvO(2)) is less invasive and may reflect the DO(2). ...

Invasive haemodynamic monitoring plays a pivotal role in critically ill patients. In this respect, central venous pressure is one of the most often used parameters. This review aims to provide an overview of the use of central venous pressure monitoring, the advantages and shortcomings, besides pitfalls. The integration of central ...

Increased venous compliance in lower limbs may be contributed to postflight orthostatic intolerance; however, direct animal studies to address the changes of venous compliance to microgravity have been rare. The purpose of this study was to determine compliance changes in femoral veins of rabbits after 21 days of head-down rest. ...

PURPOSE: To determine the effect of reactive hyperemia on human forearm vein area. METHODS: After obtaining ethics approval and informed consent, an automatic tourniquet was applied to the forearms of 20 healthy subjects for one, two, and three minutes, at pressures of 25 mmHg, 200 mmHg, then 25 mmHg. A ...

OBJECTIVE: To review the clinical use of central venous pressure measurements. DATA SOURCES: The Medline database, biographies of selected articles, and the author's personal database. DATA SYNTHESIS: Four basic principles must be considered. Pressure measurements with fluid-filled systems are made relative to an arbitrary reference point. The pressure that is ...

Arterial and venous pressures were measured in hagfishes subjected to acute changes in salinity. The osmotic pressure of the seawater (SW) was increased or decreased by approximately 10%. Sixty minutes after the change in medium osmolarity the osmotic pressure of the blood corresponded with that of the medium. Following transfer ...

Subambient central venous pressure (Pven) and modulation of venous return through cardiac suction (vis a fronte) characterizes the venous circulation in sharks. Venous capacitance was estimated in the dogfish Squalus acanthias by measuring the mean circulatory filling pressure (MCFP) during transient occlusion of cardiac outflow. We tested the hypothesis that ...

Knowledge of central venous pressure (CVP) is considered valuable in the assessment and treatment of various states of critical illness and injury. OBJECTIVES: We tested a noninvasive means of determining CVP (NICVP), by monitoring forearm volume changes in response to externally applied circumferential pressure to the upper arm veins. METHODS: ...

A 22 years male admitted with severe pancreatitis with central venous catheter implanted for central venous pressure monitoring and for providing total parental nutrition developed catheter fragment embolus due to accidental fracture of the same while manipulating it. Non surgical retrieval of the same was done by radiological intervention without ...

This is the first study to examine the hypothesis that prolonged sitting is associated with procoagulant changes in the local lower-limb venous system. A comparison was made with upper-limb venous changes. Changes in markers of thrombin generation, fibrinolysis, endothelial perturbation and haemoconcentration were analysed as 10 healthy adult male participants ...

OBJECTIVES: Neurological complications after cavopulmonary connections like bidirectional Glenn shunt and Fontan connection are occasionally encountered in the postoperative period. We discuss such a case of bilateral bidirectional Glenn shunt which developed convulsive syncope postoperatively. CASE: A 5-year-old cyanotic girl diagnosed as tricuspid atresia with pulmonary stenosis without any spell ...

PURPOSE OF REVIEW: The proper use of central venous pressure requires a good understanding of basic measurement techniques and features of the waveform. RECENT FINDINGS: If attention is not paid to proper leveling of the transducer and consideration of transmural pressure then major errors are made in the use of ...

STUDY OBJECTIVE: To assess the reliability of peripheral venous pressure (PVP) as a predictor of central venous pressure (CVP) in the setting of rapidly fluctuating hemodynamics during orthotopic liver transplant surgery. DESIGN: Prospective clinical trial. SETTING: UCLA Medical Center, main operating room-liver transplant surgery. PATIENTS: Nine adult patients with liver ...

PURPOSE OF REVIEW: Mixed venous and central venous oxygen saturations reflect the balance between oxygen requirement and oxygen delivery, and thus may be used to assess the adequacy of tissue oxygenation. This review discusses recent data on the impact of using venous oximetry by obtaining mixed venous oxygen saturation or ...

BACKGROUND AND OBJECTIVES: Positive end-expiratory pressure may alter cardiac function and systemic haemodynamics. As transplanted livers may be sensitive to liver congestion, the aim of our study was to evaluate the effect of positive end-expiratory pressure on the cardiovascular system and in particular on central venous and iliac venous pressure ...

The mechanical properties of human veins remain incompletely known. However they play an important part in number of physiological and pathological situations, as hemodynamic adjustment to orthostasis, deep venous thrombosis (DVP) and chronic venous insufficiency (CVI). The aim of the study was to describe the pressure/volume (area) relationship of some ...

A 40-year-old woman who had primary pulmonary hypertension presented with dilated episcleral vessels, venous stasis retinopathy, and open-angle glaucoma with reflux of blood in Schlemm's canal in both eyes. Intraocular pressure was controlled with anti-glaucoma medication along with systemic treatment of congestive heart failure. However, venous stasis retinopathy progressed with ...

Verification of appropriate precordial Doppler probe position over the anterior chest wall is crucial for early detection of venous air embolism. We studied responses to normal saline (NS) and carbon dioxide (CO2) test injections at various probe locations during elective craniotomy. All patients received four IV injections (10 mL of ...

Right heart failure is associated with increased systemic venous pressure, which can be diagnosed clinically with the findings of elevated jugular venous pressure, pulsatile liver and distinctive cardiac murmurs (precordial systolic). Severe tricuspid regurgitation (TR) has occasionally been known to lead to marked pulsation of varicose veins. We report three ...

In puppies weighing 500 to 1,500 grams, 50 ml./kg. saline was rapidly infused and the following results were obtaied. (1) With the use of the same amount of fluid per unit body weight, the rate of elevation of central venous pressure was higher in smaller puppies. (2) With the infusion ...

In the present study, the effects of L-dopa treatment on cardiovascular variables and peripheral venous tone were assessed in 13 patients with Parkinson's disease (PD) with Hoehn and Yahr stages 1-4. Patients were investigated once with their regular treatment and once after 12 h of interruption of L-dopa treatment. L-Dopa ...

BACKGROUND AND OBJECTIVE: Previous studies in adults have demonstrated a clinically useful correlation between central venous pressure (CVP) and peripheral venous pressure (PVP). The current study prospectively compared CVP measurements from a central versus a peripheral catheter in kidney recipients during renal transplantation. METHODS: With ethics committee approval and informed ...

OBJECTIVE: To study the influence on central venous pressure (CVP), measured at the distal port, of crystalloid infusions administered through the proximal port(s) of a central venous multi-lumen catheter. PATIENTS: Thirty-one intensive care patients. INTERVENTIONS: CVP was measured at the distal port of a multi-lumen catheter inserted in the subclavian ...

OBJECTIVE: Transthoracic echocardiography (TTE) has been used clinically to disobstruct venous drainage cannula and to optimise placement of venous cannulae in the vena cava but it has never been used to evaluate performance capabilities. Also, little progress has been made in venous cannula design in order to optimise venous return ...

We investigated the effects of heat acclimation on venous and arterial compliance in humans. Four male and four female volunteers were exposed to an ambient temperature of 40 degrees C and relative humidity of 40% for 4 h (1330-1730 hours) per day for 9-10 consecutive days. The calf venous compliance ...

A major concern in surgery is the prevention or control of bleeding. The ligature and the clip are the hallmarks of the last century of modern surgery. Therapeutic embolization is not really used to stop hemorrhage but to treat aneurysms and so prevent future rupture and bleeding. Blood clotting within ...

Central venous pressure (CVP) is an important physiological parameter, the correct measure of which is a clinically relevant diagnostic tool for heart failure patients. A current challenge for physicians, however, is to obtain a quick and accurate measure of a patient's CVP in a manner that poses minimum discomfort. Current ...

BACKGROUND: Preoperative assessment of forearm superficial venous diameter may predict early failure of newly created arteriovenous fistulas for haemodialysis access. However, early failure and non-maturation rates remain high (up to 30%) and reported cut-off diameters are inconsistent. We hypothesize that this inconsistency is due to differences in the methods used ...

BACKGROUND AND AIMS: Hypovolemia after bowel preparation as well as capnoperitoneum (CP) may compromise hemodynamic function during laparoscopic colonic surgery. A fall in arterial pressure after induction of anesthesia is often answered by generous fluid administration, which might impair "fast-track" rehabilitation. Intraoperative assessment of the needed infusion volume is difficult ...

According to the concept of Guyton, cardiac output is largely controlled by venous return, which is determined by the difference between mean systemic venous pressure and right atrial pressure. In the analysis of the venous return curve, other authors have suggested that right atrial pressure is the dependent variable and ...

BACKGROUND: Accepted diagnostic criteria exist for the diagnosis of deep vein thrombosis (DVT). However, no uniform definition for the diagnosis and treatment of the post-thrombotic syndrome (PTS) exists. We examined the various definitions of PTS that are used and their relationships with invasive venous pressure measurement. METHODS: Patients who had ...

The effects of adrenergic stimulation on mean circulatory filling pressure (MCFP), central venous pressure (P(CV)) and stroke volume (Vs), as well as the effects of altered MCFP through changes of blood volume were investigated in rattlesnakes (Crotalus durissus). MCFP is an estimate of the upstream pressure driving blood towards the ...

Continuous central pressure monitoring and simultaneous continuous infusion via the same central venous catheter are sometimes necessary. Based on theoretical calculations and experimental measurements, we have determined that pressure monitoring is essentially unaffected if the continuous infusion rate is 50 ml.h(-1) or less for an adult and a paediatric central ...

Patients with chronic venous insufficiency often have combined superficial and deep venous incompetence. The aims of this study were to determine the effects of superficial venous surgery (SVS) on deep venous haemodynamics and on ambulatory venous pressure (AVP) and to determine if the AVP tourniquet test can predict the effect ...

Chronic venous insufficiency is linked to venous hypertension and forces of shear stress on the endothelium. Venous hypertension depends upon two forces: the weight of a column of blood from the right atrium transmitted through the valveless vena cava and iliac veins to the femoral vein, and pressure generated by ...

Recent histologic and immunocytochemical evidence of venous leg ulcers supports the hypothesis that lesions observed at different stages of chronic venous insufficiency may be associated with, and possibly caused by, an inflammatory process. Evidence has been obtained that venous valve deficiency may be associated with leukocyte infiltration into valve leaflets; ...

BACKGROUND: Hypovolaemia may be considered to represent a volume-restricted cardiac output (CO), but CO varies inversely with the haemoglobin concentration (Hb) and a maximal mixed venous oxygen saturation (SvO2) may be a better target for volume administration than a maximal CO. METHODS: In 10 anaesthetized pigs, volume loading with 6% ...

The effects of treadmill exercise on components of the cardiovascular (heart rate, mean arterial blood pressure, central venous pressure, venous return) and respiratory (minute ventilation, tidal volume, breathing frequency, rate of oxygen consumption, rate of carbon dioxide production) systems and on intra-abdominal pressure were measured in the American alligator, Alligator ...

The decrease in pre-capillary resistance in the human calf during gradual cumulative increases in venous congestion pressure has been proposed to represent vasodilator signalling between the venous and arterial microcirculations. The present study investigated whether prostaglandins are involved in this local flow regulation by measuring calf blood flow and microvascular ...