Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Plasma Volume”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 163 records · Page 9Linked to original sources
PubMed2005

A subnormal plasma volume in formerly preeclamptic women is associated with a low venous capacitance.

OBJECTIVE: Pregnancy induces a smaller rise in plasma volume in formerly preeclamptic women with a pre-existent subnormal plasma volume than in their counterparts with a normal plasma volume. These women also have a three times higher recurrence rate of pregnancy-induced hypertensive disorders. In this study we tested the hypothesis that a subnormal plasma volume in these women is related to a lower capacitance of their venous compartment. METHODS: In 31 nonpregnant formerly preeclamptic women with a subnormal plasma volume and eight parous controls, we infused intravenously 500 mL of a modified gelatin solution over 30 minutes. Before and after infusion we measured the circulating levels of alpha-atrial natriuretic peptide (alpha-ANP) and active plasma renin concentration (APRC). During volume loading, we recorded the change in heart rate, stroke volume, and cardiac output using pulse contour analysis. We measured the ratio of percent change in blood volume and percent change in cardiac output during volume loading as a marker for venous capacitance. RESULTS: During volume loading, patients differed from controls by a larger rise in alpha-ANP, pulse rate, and cardiac output, and by a lower estimated venous capacitance. The concomitant response of stroke volume and APRC did not differ appreciably between groups. CONCLUSION: Formerly preeclamptic women with a subnormal plasma volume differ from controls with a normal plasma volume by a reduced venous capacitance. These results support our hypothesis that, in these women, a subnormal plasma volume indicates the presence of a subnormal venous capacitance.

Adult↗
PubMed1986

Estrogen effects on plasma volume, arterial blood pressure, interstitial space, plasma proteins, and blood viscosity in sheep.

In adult castrated ewes the infusion of 17 beta-estradiol for 3 weeks was associated with a 12% increase in body weight, a 20% increase in whole blood volume (mainly due to a 27% increase of plasma volume), a 13% decrease in mean arterial blood pressure, and a 40% increase in heart rate. The change in plasma volume correlated with the change in estradiol concentration (r = 0.72). Most of the fluid was retained in the interstitial space, as represented by a 6 kg weight gain, 10% of which was in the intravascular compartment. Whole blood and plasma viscosity increased 16% and 21%, respectively, thus reversing some of the blood volume effects toward a hyperdynamic cardiovascular state. We conclude that many of the cardiovascular and hematologic changes with estrogen administration are similar to the changes observed during pregnancy, with the proposed requirement of decrease in mean arterial blood pressure as a condition for blood volume expansion.

Animals↗
PubMed1987

Determination of plasma volume in swine by the enzyme-dilution method.

Plasma volume of six young swine was determined by simultaneous dilution in the plasma of two purified porcine enzymes, aspartate aminotransferase (AST) and alanine aminotransferase (ALT), and Evans blue dye. Ninety-minute time-activity and time-concentration curves were obtained, and the dilution spaces of each plasma indicator at the time of injection were estimated by extrapolation of data from the first 30 min after injection. Plasma volumes estimated using the two enzymes agreed closely with each other (AST, mean 50.2 ml/kg; ALT, mean 49.8 ml/kg) and were 11% smaller than those determined using Evans blue dye (mean 56.3 ml/kg). Plasma volumes calculated from the AST and ALT activities and Evans blue dye concentration in a sample drawn 5 min after injection very closely approximated those obtained by extrapolation. These values were comparable to previously published estimates of plasma volume for swine of equivalent weight. Endogenous plasma levels of AST and ALT activity were measured in samples drawn from five swine before and after a 40% blood loss. No significant change in AST or ALT activities occurred after hemorrhage.

Alanine Transaminase↗
PubMed2002

Hydroxyethyl starch and modified fluid gelatin maintain plasma volume in a porcine model of septic shock with capillary leakage.

OBJECTIVE: To compare the effects of different volume replacement therapies on maintenance of plasma volume in septic shock and capillary leakage syndrome. DESIGN AND SETTING: Prospective randomized, controlled animal laboratory study in a university animal laboratory. MEASUREMENTS AND RESULTS: Twenty-five fasted, anaesthetized, mechanically ventilated and multi-catheterized pigs (20.8+/-1.8 kg) received 1 g/kg body weight faeces into abdominal cavity to induce sepsis and were observed over 8 h. Five animals each received volume replacement therapy with modified fluid gelatin 4% or 8% (MFG4%, MFG8%), 6% HES 200/0.5, or Ringer's solution and were compared to controls receiving 6% HES 200/0.5. Infusion rate was titrated to maintain a central venous pressure of 12 mmHg. Plasma volume was determined using (51)Cr-labelled erythrocytes and standard formulae. Albumin escape rate was calculated using technetium (99m)Tc-labelled albumin. Colloid osmotic pressure, systemic haemodynamics and oxygenation were obtained before and 4 and 8 h after induction of sepsis. Plasma volume was reduced in the Ringer's solution group (-46%) but was maintained in HES (+/-0%), MFG4% (+4%), MFG8% (+23%) groups. Albumin escape rate increased in HES (+52%), MFG4% (+47%), MFG8% (+54%) and the Ringer's solution group (+41%) compared to controls. CONCLUSION: In this porcine septic shock model with concomitant capillary leakage syndrome, confirmed by an increased albumin escape rate, the artificial colloids HES, MFG4%, and MFG8% maintained plasma volume and colloid osmotic pressure. These results suggest the intravascular persistency of artificial colloids in the presence of albumin leakage. An editorial regarding this article can be found in the same issue (http://dx.doi.org/10.1007/s00134-002-1283-9)

Albumins↗
PubMed1997

Effect of therapeutic paracentesis on plasma volume and transvascular escape rate of albumin in patients with cirrhosis.

BACKGROUND/AIMS: Circulatory abnormalities with activation of vasoconstrictor systems after large-volume paracentesis are generally considered secondary to an increased extravasation of fluid from the intravascular compartment to the extravascular space with subsequent reduction in plasma volume. To test this hypothesis, plasma volume, the transvascular escape rate of albumin, the absolute escape rate of albumin and the activity of vasoconstrictor systems were measured in 25 cirrhotic patients with ascites in baseline conditions and 2 days after total paracentesis with plasma volume expansion. METHODS: Plasma volume and the transvascular escape rate of albumin, the fraction of albumin passing from the intravascular to the extravascular space per unit of time, were assessed through the plasma disappearance curve of radioiodinated human albumin. The absolute escape rate of albumin, the total flux of albumin from intravascular to extravascular space per unit of time, was also calculated. RESULTS: Eight of the 25 patients (32%) developed marked activation of vasoconstrictor systems after paracentesis. In these patients, plasma renin activity and plasma norepinephrine concentration increased from 6.6+/-2 to 23.4+/-11 ng x ml(-1) x h(-1) and 776+/-229 to 989+/-258 pg/ml, respectively (p<0.05). No significant changes in these parameters were found in the remaining 17 patients. The activation of vasoconstrictor systems occurred in the absence of changes in plasma volume (3456+/-276 vs 3476+/-264 ml, NS), transvascular escape rate of albumin (10.4+/-1 vs 10.9+/-2%/h, NS) and absolute escape rate of albumin (9.9+/-1.9 vs 10.5+/-0.7 g/h, NS). CONCLUSIONS: These results do not support a contraction of plasma volume as the mechanism responsible for activation of vasoconstrictor systems after paracentesis. Rather, the activation of vasoconstrictor systems in the absence of changes in plasma volume suggests that paracentesis accentuates the impairment of "effective" blood volume present in cirrhotic patients with ascites.

Blood Pressure↗
PubMed2002

Does indocyanine green accurately measure plasma volume early after cardiac surgery?

UNLABELLED: Potential overestimation of plasma volume (PV) determination by the conventional indocyanine green (ICG) dilution method (PV-ICG) can occur when generalized capillary protein leakage is present, because ICG binds to proteins. We recently reported that this overestimation can be recognized by simultaneous measurement of the initial distribution volume of glucose (IDVG). We examined whether overestimation of PV-ICG and further ICG-pulse dye densitometry-derived plasma volume (PV-PDD) can occur early after cardiac surgery by using the PV-ICG/IDVG ratio as an indicator. Possible overestimation was defined as a ratio higher than 0.45. Twenty-four consecutive postcardiac surgical patients were enrolled. PV-ICG, PV-PDD, and IDVG were calculated simultaneously after admission to the intensive care unit and on the first postoperative day. The mean +/- SD PV-ICG/IDVG ratio for 47 recordings was 0.38 +/- 0.05. Four had a PV-ICG/IDVG ratio higher than 0.45, and the highest was 0.48. The mean PV-PDD/IDVG ratio for a total of 47 recordings was 0.39 +/- 0.10. There were extremely high or low ratios observed in PV-PDD determinations, but they were not observed in PV-ICG determinations. Results suggest that most of the PV-ICG measurements are accurate, but inaccuracy of PV-PDD can occur early after cardiac surgery. IMPLICATIONS: Overestimation of indocyanine green-derived plasma volume can occur in the presence of generalized capillary protein leakage. This overestimation was examined early after cardiac surgery by using the simultaneous measurement of the initial distribution volume of glucose. We suggest that overestimation of the traditional dye dilution method is negligible, but apparent over- or underestimation of pulse dye densitometry-derived plasma volume cannot be negligible.

Adult↗
PubMed1966

A comparison of Coomassie blue dye with radioiodinated albumin as an indicator for plasma volume estimation in human subjects.

Plasma volume has been estimated in 10 human subjects using Coomassie blue and (131)I radioiodinated human serum albumin dilution methods simultaneously. Three different methods of correction used by previous workers to overcome the error due to early dye loss were applied. Satisfactory agreement with the established radioiodinated albumin method was only obtained by extrapolation of the semilogarithmic plot of Coomassie blue plasma dye concentration between five and 10 minutes to the time of injection. The significance of the controversial Evans blue ;mixing curve' is discussed. An analogous phase in the Coomassie blue disappearance slope is considered to be due to initial rapid loss of dye from the circulation rather than to the process of mixing. It is shown that Coomassie blue fulfils the criteria listed in the discussion for plasma volume estimation.

Adult↗
PubMed1998

The influence of exercise-induced plasma volume changes on the interpretation of biochemical parameters used for monitoring exercise, training and sport.

A number of studies have demonstrated considerable plasma volume changes during and after exposure to different environmental and physiological conditions. These changes are thought to result from transient fluid shifts into (haemodilution) and out of (haemoconcentration) the intravascular space. If the levels of plasma constituents are to be routinely measured for research purposes or used as indicators of training adaptation or the health of an athlete, then it is important to consider the dynamic nature of plasma volume. Controversy still exists over the relevance of plasma volume interactions with plasma constituent levels, and while some investigators have taken plasma volume shifts into account, others have chosen to ignore these changes. Bouts of acute exercise have been shown to produce a transient haemoconcentration immediately after long distance running, bicycle ergometry and both maximal and submaximal swimming exercise. While these changes are transient, lasting only a few hours, other studies have reported a longer term haemodilution following acute exercise. In addition, endurance training has been shown to cause long term expansion of the plasma volume. It would, therefore, seem important to consider the influence of plasma volume changes on plasma solutes routinely measured for research, and as markers of training adaptation, prior to arriving at conclusions and recommendations based purely on their measured plasma level. To further confound this issue, plasma volume changes are known to be associated with heat acclimatisation, hydration state, physical training and postural changes, all of which may differ from one experiment or exercise bout to the next, and should thus be taken into account.

Blood Chemical Analysis↗
PubMed1996

Determining blood and plasma volumes using bioelectrical response spectroscopy.

We hypothesized that an electric field (inductance) produced by charged blood components passing through the many branches of arteries and veins could assess total blood volume (TBV) or plasma volume (PV). Individual (N = 29) electrical circuits (inductors, two resistors, and a capacitor) were determined from bioelectrical response spectroscopy (BERS) using a Hewlett Packard 4284A Precision LCR Meter. Inductance, capacitance, and resistance from the circuits of 19 subjects modeled TBV (sum of PV and computed red cell volume) and PV (based on 125I-albumin). Each model (N = 10, cross validation group) had good validity based on 1) mean differences (-2.3 to 1.5%) between the methods that were not significant and less than the propagated errors (+/- 5.2% for TBV and PV), 2) high correlations (r > 0.92) with low SEE (< 7.7%) between dilution and BERS assessments, and 3) Bland-Altman pairwise comparisons that indicated "clinical equivalency" between the methods. Given the limitation of this study (10 validity subjects), we concluded that BERS models accurately assessed TBV and PV. Further evaluations of the models' validities are needed before they are used in clinical or research settings.

Adult↗
PubMed1999

Does indocyanine green accurately measure plasma volume independently of its disappearance rate from plasma in critically ill patients?

OBJECTIVE: To determine whether plasma volume determined by the indocyanine green (ICG) dilution method (PV-ICG) is equally accurate independently of its disappearance rate from plasma in the critically ill. DESIGN: Retrospective clinical investigation. SETTING: Intensive care unit of a university teaching hospital. PATIENTS AND METHODS: 192 adult patients were initially enrolled. The PV-ICG and the initial distribution volume of glucose (IDVG) were calculated utilizing a one-compartment model by simultaneous administration of ICG 25 mg and glucose 5 g on the first day of measurement in each patient. Twenty-one patients were excluded from the study because of a higher PV-ICG/IDVG ratio (> 0.45) indicating apparent overestimation of the PV-ICG associated with the generalized protein capillary leakage. The remaining 171 patients were divided into four groups according to the magnitude of their disappearance rate of ICG from plasma (Ke-ICG). RESULTS: Convergence was assumed consistently in each ICG or glucose decay curve, even in the lower Ke-ICG less than 0.10/min. The relationship between the two volumes was not statistically different among groups. CONCLUSIONS: The results suggest that the measurement of the PV-ICG can be equally accurate independently of its disappearance rate from plasma unless there is generalized protein capillary leakage.

APACHE↗
PubMed2003

Relationship of plasma volume to sympathetic tone in nulliparous women.

OBJECTIVE: We sought to determine whether resting supine plasma volume is related to sympathetic tone in healthy young nulligravid normotensive women. STUDY DESIGN: Forty women were examined in the midfollicular phase. Alpha-adrenergic tone was estimated by an examination of the late phase II blood pressure response to the Valsalva maneuver. Resting heart rate was examined to evaluate the balance of sympathetic and parasympathetic input. Plasma catecholamines were measured during supine rest. Plasma volume was estimated by Evans blue dilution. RESULTS: Plasma volume corrected for body surface area was correlated inversely to late phase II blood pressure response to the Valsalva maneuver (r = -0.31, P <.05) and was correlated directly to the cardiac R-R interval (r = 0.41, P <.01). There was no relationship of plasma volume corrected for body surface area to mean arterial pressure (r = -0.13, P not significant). We found no significant relationship of plasma epinephrine concentration (r = -0.05, P =.76) or plasma norepinephrine (r = -0.09, P =.60) with plasma volume corrected for body surface area. CONCLUSION: We conclude that plasma volume is related inversely to both an estimate of alpha-adrenergic activation and heart rate. These findings are consistent with an adaptive physiologic response that is aimed at the maintenance of blood pressure in the face of reduced plasma volume.

Adult↗
PubMed1990

Na restriction blunts expansion of plasma volume and ameliorates hyperdynamic circulation in portal hypertension.

Expansion of plasma volume may be necessary for the development of the hyperdynamic circulation in portal hypertension. In experiment 1, sham portal vein-constricted (sham PVL) rats were divided into normal diet (NL diet sham) and low-sodium diet (low-Na sham) groups. Data obtained from the NL diet sham group was used as control data in studying portal hypertensive rats, which were also divided into normal diet (NL diet PVL) and sodium-restricted (low-Na PVL) groups on the day of portal vein constriction. There were no hemodynamic differences at 3 wk between sham PVL rats on the two diets. In contrast, sodium restriction in PVL rats resulted in a significant amelioration of the hyperdynamic circulation. In experiment 2, PVL rats were fed a normal diet for 10 days, followed by allocation to NL diet PVL and low-Na PVL groups. The hemodynamic effects of sodium restriction in these animals (studied at 22 and 28 days after PVL) were similar to those observed in experiment 1. A time course for amelioration of the hyperdynamic circulation in PVL rats by sodium restriction is described. Sodium restriction prevents the expansion of the plasma volume in PVL rats. Interference with plasma volume expansion blunts the development of (and can ameliorate) the hyperdynamic syndrome. Plasma volume expansion seems necessary for the development of the hyperdynamic circulation in portal hypertension.

Animals↗
PubMed1995

Transcapillary fluid transfer and plasma volume changes in response to quiet standing and LBNP.

Quiet standing is one of the conditions of daily life. Still, it may lead to acute circulatory failure even in normal man, a phenomenon ascribed mainly to the early large pooling of blood and secondary decrease in central blood volume. Reduction of plasma volume (PV) by filtration in dependent regions apparently contributes, but there is no indication that this process is of major importance during short periods of standing still in normal life. Hence, studies have indicated that the plasma fluid loss occurs at relatively slow rate due to the presence of protective mechanisms that prevent rapid fluid loss.

Adult↗
PubMed1991

Blood and plasma volumes determined by carbon monoxide gas, 99mTc-labelled erythrocytes, 125I-albumin and the T 1824 technique.

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 amount of CO in moles (nCO) were used to calculate the total amount of circulating haemoglobin. Blood volume was calculated by dividing this figure with the haemoglobin concentration and plasma volume by multiplying the blood volume with 1-haematocrit. The calculated blood and plasma volumes were compared with the simultaneously measured volumes by 99mTc-labelled erythrocytes, 125I-albumin and T 1824 (Evans Blue). Mean blood volume determined with CO was 4557 ml (3251-6576 ml) compared with 4527 ml (3390-6527 ml) with 99mTc-labelled erythrocytes (r = 0.97). Mean plasma volume by T 1824 was 2895 ml (1972-3658 ml) vs 2898 ml (1815-3714) ml using 125I-albumin, (r = 0.99). The plasma volumes calculated from the blood volumes determined by the erythrocyte-labelling methods were 5-10% lower than those measured with labelled albumin. There was a better correlation between the plasma volumes by the albumin methods and by the CO-technique (r = 0.98 and r = 0.97, respectively) than between the plasma volumes by the albumin methods and by 99mTc-erythrocytes (r = 0.90 and r = 0.87, respectively).

Aged↗
PubMed2003

Low plasma volume following pregnancy complicated by pre-eclampsia predisposes for hypertensive disease in a next pregnancy.

OBJECTIVE: A large number of women with a history of pre-eclampsia/HELLP have a low plasma volume at least six months postpartum. The objective of this study was to determine whether a low plasma volume in formerly pre-eclamptic women and HELLP patients is associated with an increased risk for recurrent hypertensive complications in a next pregnancy. DESIGN: Prospective observational study. SETTING: Tertiary obstetric centre. SAMPLE: Formerly pre-eclamptic women and controls. METHODS: In 316 women with a history of pre-eclampsia and/or HELLP, we measured, plasma volume along with haemodynamic, metabolic and haemostatic variables at least six months postpartum. A group of 22 healthy parous controls was used as a reference. After standardising plasma volume for body mass index, women were subdivided into normotensive and normal plasma volume (n = 199), normotensive and low plasma volume (n = 76) and hypertensive (n = 41) subgroups, which were compared for demography, clinical parameters and course of a next pregnancy. MAIN OUTCOME MEASURES: Recurrent hypertensive disease of pregnancy. RESULTS: Relative to the normal plasma volume subgroup, normotensive women in the low plasma volume subgroup have a higher body mass index, a lower total vascular compliance and a shorter estimated systemic circulation time. They have a higher HOMA index and higher fasting triglyceride levels. In normotensive and hypertensive former patients alike, low plasma volume is associated with a higher recurrence of hypertensive complications in a next pregnancy compared with normotensive women with normal plasma volume. CONCLUSION: Low plasma volume in normotensive women with a history of pre-eclampsia and/or HELLP is associated with overweight, reduced vascular compliance and insulin resistance and a predisposition for recurrent pre-eclampsia and HELLP syndrome in a next pregnancy.

Adult↗
PubMed1992

Plasma volume, osmolarity, total protein and electrolytes during treadmill running and cycle ergometer exercise.

While haemoconcentration due to loss of plasma volume is well established during cycling, the existence of similar changes during running remains contentious. This study compared the changes in plasma volume and associated blood indices during 60 min of running and cycling at the same relative intensity (approximately 65% VO2max), with all changes referenced to blood indices obtained after 30 min seated at rest on a cycle ergometer. Plasma osmolarity increased similarly with both forms of exercise but was less than predicted for water loss alone, such that there was a net loss of sodium during exercise and of potassium postexercise, with essentially no loss of protein. Plasma volume decreased similarly (approximately 6.5%) in both exercise trials, but while that with cycling was initiated by exercise itself and was essentially maximal within 5 min, the reduction in plasma volume in the running trial was induced by adopting the upright posture and was complete before exercise began. These data would indicate that different mechanisms are responsible for the changes in plasma volume induced by running and cycling, while the similarity of change would suggest that there is a lower limit to any reduction in plasma volume, regardless of mechanism. Furthermore, the observation that the changes in plasma volume were complete before or early in exercise, would imply that oral water ingestion during prolonged exercise, which is essential for thermoregulation, may be more concerned with homeostasis of extravascular water rather than plasma volume.

Adult↗
PubMed1986

Plasma volume in black women with eclampsia.

Plasma volume was estimated in 11 black women with eclampsia and compared with 9 normotensive primigravidas. With respect to age, weight and height the two groups were similar and although plasma volume was 4.1% less in the reference group, this difference was not statistically significant.

Eclampsia↗
PubMed1989

Comparison of indirect methods to estimate plasma volume changes during hemodialysis.

Changes in plasma volume and intravascular protein mass were studied in a group of patients receiving routine hemodialysis. The methodology involved measuring pre- and post-dialysis hematocrits, total plasma proteins, colloid osmotic pressure, albumin and IgG concentrations. Correlations were sought among the plasma volume changes provided by equations using the listed, measured variables. The differences between predicted and measured post-dialysis protein concentrations were used to estimate net gain or loss of protein. Overall, no net gain or loss of intravascular proteins was observed, but the results raised the possibility that changes in intravascular proteins might occur in individual cases. These measurements may be useful in evaluating patients with recurrent dialysis-induced hypotension.

Blood Proteins↗