SEARCH · Search PubMed
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.
Explore the source record for details and available documents.
Continuous blood mass-density measurements were performed in anesthetized dogs and injections of 0.7-1.4 ml/kg isotonic saline solution were applied. The resulting density dilution curves were used to compute blood volume, total flow in the aorta and local flow in the coronary circulation. Blood volume calculations were compared with blood volume determined by Evans blue injections and a close agreement was found. Blood flow determined by density dilution was independent from the investigated sites of injection or sampling. We conclude from these results that small volume injections of isotonic saline solution can be used to determine blood volume and flow by density dilution. In addition to these findings, a marked retention of the injected fluid was observed. Possible mechanisms to explain this retention include albumin deposition in the endothelial pores and/or variations of blood viscosity and capillary pressure.
This paper describes a dynamic blood volume determination which is faster and more accurate than the classic method. The new method determines blood volume by means of the product of the mean transit time of the circulation and the cardiac output. The mean transit time is calculated from the body transport function. To examine the precision of the dynamic method the blood volume of 24 patients was determined in both the dynamic and the classical way, using radioactively labelled erythrocytes. The comparison of the two methods resulted in a correlation coefficient of r = 0.77. The dynamic method of blood volume determination will be helpful especially in risk patients to accurately determine the quantities of fluids to be administered.
OBJECTIVE: There exists no method so far for the determination of circulating blood volume as an important parameter of circulatory function widely usable under clinical conditions. Therefore, the present study was designed to investigate whether identical distribution spaces could be measured by two methods for blood volume determination using sodium fluorescein (SoF) and radioactively labelled red blood cells (51Cr*). DESIGN: Comparative study. SETTING: Operating theatre, recovery room, or intensive care unit of a university hospital. PATIENTS: 35 patients undergoing abdominal, urological or vascular surgery. INTERVENTIONS: Simultaneous determinations of blood volume using SoF and 51Cr* in the intra- and postoperative period. RESULTS: There were no significant differences between the calculated means of blood volume (4,445 vs. 4,407 ml), red cell volume (1,554 vs. 1,540 ml), and plasma volume (2,891 vs. 2,807 ml) for 51Cr*-vs. SoF-stained red blood cells. The coefficient of correlation between the two methods was r = 0.95. The mean percentage error was -0.6% between the two methods, the precision 5.6%. CONCLUSIONS: SoF-stained erythrocytes allow a determination of the same distribution space as the well-established radioactive method using 51Cr*. Therefore, SoF-staining may replace 51Cr* labelling of red blood cells for the determination of blood volume in patients.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
1. The blood volume of the mouse has been measured using (59)Fe-labelled red cells to determine the red cell volume and (131)I-labelled human serum albumin to determine the plasma volume.2. Values for the blood volume of 95.0 +/- 1.5, 96.3 +/- 2.7 and 84.7 +/- 1.2 ml./kg body wt. were found for CSI female, CBA female and CBA male mice respectively.3. A marked discrepancy was observed between the venous (cardiac) haematocrit and the whole body haematocrit.4. The blood volume of the mouse must be determined from the red cell volume and the plasma volume, measured using appropriate labels, and not from the red cell volume or the plasma volume using the venous haematocrit.
This paper describes the investigation of a new mathematical method of calculating blood volume. The new method determines the blood volume by calculating the product of the mean circulation transit time. The mean transit time is calculated from the body transport function. To examine the accuracy of the LOGNORMAL-NLSQ technique, 45 concentration time curves were measured in an in vitro recirculation model with variable clearance. The calculated volume was 4% smaller than the actual volume. This may be attributed to the functional dead space within the model, and is tolerable for clinical situations. The LOGNORMAL-NLSQ technique might acquire considerable importance in future, especially since it provides accurate results very quickly.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Accurate blood volume determination is useful both clinically and in research. In many instances, however, direct measurement of blood volume is impractical due to the risk of bacterial contamination. For this reason, mass is often used to estimate volume. The relationship between mass and volume (density) varies with different suspension solutions and hematocrits. In this paper, equations are derived to calculate volume as a function of hematocrit and mass for pooled red cells suspended in four solutions: CPD plasma (whole blood), additive solutions 1 and 3 (AS-1 and AS-3), and saline. To validate this approach, the actual versus predicted blood volumes in 10 individual blood samples suspended in either AS-1 or saline are compared. The equations predict the volume of blood to within 0.5% and 1.0% in samples with low/normal and high hematocrits (15% to 85%, respectively). Use of these equations allow for accurate and rapid conversion of mass to volume for these blood products.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
OBJECTIVE: To develop and evaluate a new method for blood volume measurements using hydroxyethyl starch as a dilution marker. DESIGN: Laboratory and clinical investigation. SETTING: Neurosurgical operating rooms and anesthesiological laboratories of a university hospital. PATIENTS: Twelve patients who underwent a neurosurgical operation. INTERVENTIONS: Anesthesia and operations were carried out by physicians who were not involved in the study. In addition, blood samples were drawn from 50 volunteers. MEASUREMENTS AND MAIN RESULTS: Blood volume measurements by the hydroxyethyl starch method were validated in vivo by comparison with a conventional carbon monoxide technique. Patients were intravenously injected with hydroxyethyl starch (100 mL) and received simultaneously an injection of carbon monoxide (50 mL) into a closed-circuit ventilation system. Blood samples obtained before and 5 mins after injection were analyzed for carboxyhemoglobin and glucose plasma concentrations after acidic hydrolysis of hydroxyethyl starch. Blood volume was calculated from the difference between glucose concentrations measured after hydrolysis in the plasma, before and after the addition of hydroxyethyl starch. In vitro, the hydroxyethyl starch method had an error and a precision of approximately 2%. In vivo, simultaneous measurements of blood volume using hydroxyethyl starch and carbon monoxide demonstrated a high correlation (r2 = .96, p < .001) between these methods. The mean difference between the two methods relative to their average value was 1.0 +/- 3.5%; the bias was 52.3 mL, and the 95% confidence interval was -64.0 to +168.7 mL. CONCLUSIONS: Blood volume determination by the hydroxyethyl starch method is accurate and rapid and may enhance perioperative monitoring of fluid and blood therapy.