A thermodilution catheter and computer system has been developed to measure right ventricular ejection fraction and volumes. To evaluate the performance of this method, the thermodilution system was evaluated in an in vitro pulsatile flow model. Thermodilution measurements of ejection fraction (EF), cardiac output (CO), stroke volume (SV), end-diastolic volume ...

Left ventricular pressure is dependent on both ventricular volume and ventricular ejection flow. These dependencies are usually expressed by ventricular elastance, and resistance, respectively. Resistance is a one-valued effect only, when ejection flow either is constant or increases. Decreasing ejection flow elicits a third effect: a decrease of elastance. The ...

Comparative analysis of some basic lung indices obtained from a screening investigation of the flow volume curve by using two techniques, with a nose clip and without a nose clip, was made on a cohort of 86 workers in a factory shop for the production of bearings. We found no ...

We investigated the effect of a 10% cyclic blood volume change with a period of 2 or 4 min to study the short-term control of blood volume. In experiments with pentobarbital-anesthetized rabbits, the blood density variation over a 2-min cycle is 0.94 +/- 0.04 (SE) g/l, and the plasma density ...

Administration of anabolic steroids carries many risks. We present a series of 15 patients with primary hypogonadism who as a group had statistically significant increases in whole body hematocrit and red blood cell volume while on testosterone therapy of 300 mg. intramuscularly every 3 weeks. A small decrease in plasma ...

The effect of acute and sequential volaemic changes on the gastroduodenal flow of saline was assessed in 23 anaesthetized dogs following two different experimental protocols. Hypervolaemia, by i.v. infusion of saline, induced a gradual decrease on gastroduodenal flow which amounted to 76% below control values (P less than 0.001) when ...

The relationship between effective blood volume and related hormones in burn patients following resuscitation is not well understood. Previous reports have suggested that hormone secretion is altered by a resetting of neural control mechanisms. Serum and urine sodium, plasma renin activity, serum ADH, cardiac index, effective renal plasma flow, and ...

Residual HIV-infected blood in needles and syringes is a source of HIV infection. Using radiolabelled blood we have stimulated needlestick injuries and sharing of syringes by intravenous drug users and quantified the volumes of blood which could be transferred to recipients in these situations. Up to 0.75 microliters of blood ...

The flow and volume dependence of the total resistance of the respiratory system (Rrs) was investigated in six mechanically ventilated patients with chronic obstructive pulmonary disease (COPD) using a simple, rapid method. Isovolume Rrs-flow (V) relationships obtained at different inflation volumes (range 0.1 to 1 L) fitted (p less than ...

This report compares the effects of two methods of heart rate (HR) perturbation on stroke volume and dorsal aortic flow in the Hamburger-Hamilton stage 24 chick embryo. The sinus venosus was paced at intrinsic HR and at 150, 125, 75, and 50% of intrinsic HR (n = 23). Alternatively, a ...

In 7 anesthetized supine dogs with an anatomic dead space of 115-162 ml, gas transport during high-frequency oscillation (HFO) was investigated at an oscillatory frequency of 15 Hz. Starting with an oscillatory volume effectively delivered to the lungs (VDEL) of 60 ml, measured on line with an ultrasonic airflow meter, ...

The total amount of circulating haemoglobin was measured in 12 subjects using a direct carbon monoxide (CO)-technique. O2 plus 50 ml CO gas was rebreathed in a small closed system for 10 min. Carboxyhaemoglobin (HbCO)% was measured with a diode-array spectrophotometer before and after the rebreathing. delta HBCO% and the ...

The relationship between [99mTc]diphosphonate uptake and bone hemodynamics was studied in canine carrageenan-induced juvenile chronic arthritis. Blood flow was determined with microspheres, plasma and red cell volumes were measured by labeled fibrinogen and red cells, and the microvascular volume and mean transit time of blood were calculated. Normal femoral epiphyses ...

Symptomatic hypovolemia in preeclampsia is often treated by volume expansion. However, the effect of this treatment on placental blood flow is unclear. In the present study the hypothesis was tested that slow volume expansion, imposed on volume-depleted rats, does not compromise placental blood flow. Mild hypovolemia was induced in rats ...

CVP increasing observed in OS "Mir" flights lets to consider it as one of the chief factors in stateman state disturbance. It is necessary to use prophylactic means to prevent pathological changes in long flights. The received data confirm physical training and clamping cuffs application efficiency as a blood volume ...

Haemodialysis (HD) should affect the erythrocytes, which constitute more than 99% of blood cells. The aim of this study was to reinvestigate the intradialytic changes in erythrocyte water content (MCV). MCV was measured during 81 HD (47 uncomplicated, 34 with hypotension), and 16 isolated ultrafiltrations (UF) performed in stable, haemodialysed ...

The washout of 133Xenon injected locally in three subcutaneous regions on three volunteers was in a repeated latin square design analyzed regarding flow values and initial clearance. Blood flow showed no dependence on injected volumes (.02-.5 ml), but there was a significant day-day variation and regional and personal differences in ...

1. Acute pancreatitis (AP) was induced by ductal injection of 2.5% sodium taurocholate saline solution. Plasma and red blood cell (RBC) volume and visceral organ blood flow were evaluated by a radioisotopic method (51Cr tracers) in 45 adult male Wistar rats (22 submitted to AP and 23 controls) 4 h ...

The relative volume of the intervillous space of the placenta of the rhesus monkey was measured in vivo using positron emission tomography (PET), a noninvasive tracer technique. 11CO-Hb and 68GaCl3 were both used in three experiments and 68Ga-EDTA in two. The tracers were administered intravenously as bolus doses to 6 ...

We have measured the effects of barium-induced cardiac contraction on the intramyocardial blood volume content of all vessels and have independently measured the blood volume content of vessels with a diameter greater than 100 microns in rat myocardium. Measurements of total intramyocardial blood volume were made by using [125I]albumin as ...

The time constant of venous drainage (tau v) of a vascular bed is an important determinant of the change in regional volume that will occur with a change in blood flow or venous pressure (Pv). Therefore, to measure tau v of the dog hindlimb, the vasculature was isolated and perfused ...

Dehydration attenuates the increase in hindlimb blood flow produced by environmental heating (EH) in baboons. This study explored whether intravascular volume repletion alone was sufficient to remove this dehydration-induced attenuation. In six unanesthetized, chronically instrumented baboons, the increases in hindlimb blood flow during EH were measured under these conditions: euhydrated, ...

To investigate whether previously reported changes in venous blood volume and composition induced by acute hypoglycaemia in humans are representative for the entire body we measured erythrocyte 51Cr content, haematocrit, plasma volume, intravascular albumin content and transcapillary escape rate of albumin in arterial and venous blood in seven healthy subjects ...

Extracellular space and blood volume were measured using 82Br dilution and 51Cr-tagged erythrocytes in 24 tumor-free patients after total gastrectomy. Eleven of the patients suffered from early dumping. Age, blood volume, and extracellular space were significantly smaller in dumpers (P less than 0.05). The dumping score could be predicted by ...

Cerebral blood volume (CBV = cerebral plasma volume [CPV] + cerebral red cell volume [CRBCV]) is one determinant of intracranial pressure. In an effort to quantitate the effects of anesthetics and PaCO2 on CBV, the authors measured cerebral plasma volume (CPV) in normocapnic (PaCO2 approximately 42 mmHg) and hypocapnic (PaCO2 ...

The effect of volume expansion of extracellular fluid on gastroduodenal resistance to the flow of isotonic saline was assessed in three groups of rats using intravenous infusions of isotonic, isotonic-isoncotic, and isotonic-isoncotic-isohaemic solutions. The gastroduodenal segment of 29 male Wistar rats was barostatically perfused at a constant pressure gradient of ...

All the information regarding the forced expiratory manoeuvre are contained in the simple volume-time spirogram. Flow-volume and time-domain indices could be derived by digitising the volume-time spirogram. This paper describes an electronic means of digitising the spirogram and demonstrates its capability in deriving flow-volume and time-domain spirometric indices. The spirograms ...

Various infusion solutions are used during preoperative hemodilution or for substituting intraoperative blood loss. We examined the influence of saline 0.9%, albumin 5%, dextran 6% gelatin 3.5% and hydroxyethyl starch 6% (HES, mw 40,000 and 450,000) on primary hemostasis using the In-vitro bleeding test (IVBT) on composed blood samples of ...

We measured the energy dissipation associated with large-amplitude periodic flow through airway bifurcation models. Each model consisted of a single asymmetric bifurcation with a different branching angle and area ratio, with each branch terminated into an identical elastic load. Sinusoidal volumetric oscillations were applied at the parent duct so that ...

Enalapril maleate, an angiotensin converting enzyme inhibitor, is a vasodilator liable to modify regional blood flow. The effects of an oral dose of 40 mg enalapril maleate on indocyanine green (ICG) kinetics were assessed in nine healthy subjects. At 4 h after the administration of the drug, a 35% decrease ...

Transesophageal echocardiography (horizontal sector scan) was performed in 11 patients with secundum atrial septal defect (ASD). In all 11 patients, transesophageal echocardiography presented the definite visualization of the defect and a clear laminar shunt flow that showed its 2 peaks in late systole and late diastole. We estimated the size ...

STUDY OBJECTIVE: The aim was to evaluate the limitation on the measurement of the clearance rate of a small solute, 99mTc DTPA, from intravascular to extravascular spaces imposed by diffusion of the solute back into blood during the period of measurement. DESIGN: The technique for measuring clearance also generates the ...

We examined the effects of hypertonic saline (7%) administration during hypovolemia in the anesthetized dog on the mechanical properties of the systemic circulation that constitute the major determinants of venous return. By using a right-heart bypass preparation in which venous return from the splanchnic and non-splanchnic vascular beds was isolated ...

The present study was performed to quantify the distribution of a peptide neurotransmitter after microinjection into the medial preoptic area (POM), using a technique suitable for conscious animal preparations. The results indicate that only 50-nl volumes of injected tracer were sufficiently localized with 77 +/- 9% recovery in the POM. ...

Previous studies using intravascular tracers have shown that the apparent vascular volume in the cerebellum is 10-60% higher than that in the cerebrum. We questioned whether the extravascular volume in the cerebellum could be accounted for by the vasculature of the pia mater that covers its highly infolded surface. Estimates ...

To determine the effect of relative exercise intensity on organ blood volume and its relation to cardiac function, changes in relative blood volume and cardiac function were monitored with radionuclide techniques in 14 healthy volunteers. After labeling the subject's red cells with technetium 99m, we acquired data at rest, zero-load ...

Multiorgan hypoperfusion due to a loss of effective circulating blood volume, whether a consequence of hemorrhage or dehydration, constitutes a medical emergency. Fluid must be added rapidly to the circulatory system, in the form of blood, colloid, or crystalloid solution. The type of fluid used for volume expansion depends on ...

Impedance Plethysmography technique has been discussed with explanation of two compartment model and parallel conductor theory for the estimation of peripheral blood flow and stroke volume. Various methods for signal enhancement to facilitate computation of blood flow are briefly described. Source of error in the estimation of peripheral blood flow ...

To our knowledge, the relationship between gallbladder volume and cystic duct function has not been studied. We hypothesized that changes in gallbladder volume would influence cystic duct resistance. The effect of gallbladder volume changes on cystic duct resistance to both prograde (emptying) and retrograde (filling) steady-state flow was tested in ...

The effect of plasma volume expansion on uteroplacental blood flow was investigated in 20 hypertensive women in the 3rd trimester of pregnancy by measuring the radioactivity in the region of the placenta with a gamma camera after an intravenous injection of indium-113. Despite a significant increase in plasma volume there ...

The optimal dose of thiopental depends both on its initial distribution kinetics, which determine its concentrations at sites of action after iv administration, and on its pharmacodynamics. The disposition of concomitantly administered thiopental and indocyanine green (ICG), a marker of intravascular space, was determined in 21 patients, aged 20-80 yr, ...

Continuous measurement of haemoglobin concentration is used to control changes of blood volume during haemodialysis. Ultrafiltration is either kept constant throughout the session or after starting with a rate (1.5 to 2 l/h), is manually controlled in order to limit blood volume reduction to a pre-set percentage. Ultrafiltration is step-wise ...

The blood volume can be measured after labelling of red blood cells with technetium-99m. In addition, the blood volume and its standard error of estimate can be calculated from the subject's sex, height and deviation from desired weight. By comparing the measured blood volume with the estimated normal blood volume ...

Bulk fluid flow or volume flow in the direction of counterion flow is a probable mechanism for enhanced flux of uncharged species by iontophoresis. Both the electrical volume force effect, resulting from the interaction of the "ion atmosphere" and the electric field, and an induced osmotic pressure effect produce volume ...

Dehydration attenuates the increase in limb skin blood flow elicited by environmental heating (EH). This study sought to determine which of the two primary effects of dehydration, increased body fluid osmolality or decreased body fluid volume, was primarily responsible for this cutaneous vasoconstrictor bias in baboons. Unanesthetized chronically instrumented baboons ...

PURPOSE OF INVESTIGATION - To determine the contribution of variations in orientation of erythrocytes (orientation effect) to the heart synchronous variations in thoracic impedance in impedance cardiography. DESIGN - The blood of four dogs was gradually replaced by stroma free haemoglobin solution, causing a decrease in resistivity and orientation effect. ...

New non-invasive multifunctional methods have been proposed for the simultaneous measurements of more than two cardiovascular hemodynamic parameters such as peripheral and central blood flow, arterial and venous pressure, peripheral flow resistance, arterial and venous elasticity, hematocrit, blood oxygenation, etc. A proper combination of one or two of the recently ...

Dehydration due to hyperthermia induces both hyperosmolality and hypovolemia. Hyperosmolality reduces evaporative cooling, and alters the thermal responsiveness of the hypothalamic center to changes in both the central and peripheral milieu. Hypovolemia also reduces the thermoregulatory response, but its effect is more variable. The potential sensor of hypovolemia is the ...

In 8 emergency care patients blood volume was determined using Cr5I labelled erythrocytes and indocyanine green (ICG). Prior to measurement of ICG in blood with a spectrophotometer, the blood was hemolyzed with Triton-X. A close correlation of r = 0.97 between the Cr51 and the ICGTR-X estimates was found; the ...

Changes of relative blood volume during haemodialysis therapy have been investigated using kinetic modelling and on-line blood volume registration by continuous haemoglobinometry. An exponential relation has been found between blood volume reduction per litre of ultrafiltrate and the amount of fluid overload. Between the amount of refilling and ultrafiltration rate ...