Measurement Of Red Cell Volume Research Articles

Biotin Labeling of Red Cells in the Measurement of Red Cell Volume in Preterm Infants

Determination of circulating red cell volume (RCV) in anemic preterm infants is, in theory, a better indicator of transfusion needs than Hb concentration. Our study reports the results of RCV measurement using biotin labeling of red cells on 40 occasions in preterm infants of 25-34 wk gestation. In 20 infants, who had estimations made within 24 h of birth, the RCV varied between 17.7 and 66 mL/kg. Twenty measurements were made at a later age at the time of a blood transfusion. RCV values were between 13.1 and 41.5 mL/kg before transfusion. In 13 infants, RCV was determined simultaneously using two methods, biotin and dilution of autologous HbF with donor HbA at transfusion. There was no significant difference between the results of RCV estimations using these two methods. Our study demonstrates that biotin labeling is an effective method for determining RCV in preterm infants.

Identification of the source of haematuria by automated measurement of red cell volume.

The mean corpuscular volume (MCV) of urinary erythrocytes was measured by a Coulter Counter in 42 patients with asymptomatic haematuria. All patients had the source of haematuria established by a renal biopsy, cystoscopy or radiology. The mean urine MCV was significantly less in those with glomerular disease (n = 21) than in those with non-glomerular haematuria (n = 21). In every patient with glomerulonephritis, urinary erythrocytes were smaller than those in their own venous blood. Conversely, urinary red cells larger than venous blood were confined to patients with a non-glomerular source. Coulter analysis of urine provides a simple and objective aid to the diagnosis of haematuria.

Blood Volume Measurement in Baboons: Simultaneous Estimation of Red Cell Volume and Plasma Volume

A method is described for frequent sequential blood volume estimation in baboons using 32P for red cell volume measurements and 125I-albumin for simultaneous plasma volume measurements. Values for red cell, plasma, and total blood volumes are reported. Close correlations of the volumes to bodyweight were demonstrated. Circulatory half-lives of the isotopes, determined from disappearance curves, confirmed their suitability for serial measurements in these baboons.

Regional brain blood flow, blood volume, and haematocrit values in the adult rat.

Measurements of red cell volume, plasma volume, and tissue haematocrit (Hct) were made in 14 brain regions in adult rats using 51Cr-tagged red cells and 125I-labeled human serum albumin. The mean large vessel (systemic artery) Hct was 41.8, total body Hct was 35.3, and of the brain regions, the lowest value (septal nucleus) was 25.91 and the highest (visual cortex) was 32.05. The lowest blood volume was 6.29 microliters g-1 (caudate putamen) and the highest was 14.44 microliters g-1 (inferior colliculus). There was a significant difference between regions in both blood volume and tissue blood Hct. When brain regions were ranked in order of blood volume, this did not coincide with the order for blood flow.

Isovolumetric sphering of erythrocytes for more accurate and precise cell volume measurement by flow cytometry.

AbstractTypical mammalian erythrocytes are biconcave disks. Flow cytometric light‐scattering measurements of red cell volume show large, orientation‐dependent variations in signal size. To eliminate errors caused by shape factors, we sphere erythrocytes isovolumetrically on an Auto‐Analyzer manifold (Technicon Instruments Corp., Tarrytown, N. Y.) using a carefully controlled ratio of concentrations of a salt of long chain sulfated fatty alcohol (e.g.), sodium dodecyl sulfate (SDS) to albumin in neutrally buffered isotonic saline, producing a suspension with at least 2 1/2 hours of stability with respect to cell volume, cell count and retention of hemoglobin. A two‐step manifold modification of this procedure is preferred. It uses the endogeneous serum protein and a first SDS‐saline reagent without added albumin at a low dilution, and further dilution with a second SDS‐saline containing a very low concentration of glutaraldehyde. This bypasses a serious shelf life problem with the albumin‐SDS reagent.Microhematocrit and Coulter electronic impedance measurements were correlated with light‐scattering measurements on our own flow cytometer system of unsphered, sphered, and sphered and fixed samples. These reveal marked superiority over unsphered samples (e.g., reduced coefficients of variation of cell volume and improved correlation with microhematocrit) of the sphered and of the sphered and lightly fixed cells. The resulting tighter unimodal cell volume distributions also provide the following advantages: (1) The separation of signals of large platelets from that of the smallest red cells is substantially increased permitting better resolution of microcytic red cells in some abnormal bloods, and (2) bimodality of red cell volume distribution in abnormal bloods is more easily resolved.

Experience with Continuous Ambulatory Peritoneal Dialysis in Belgium

This paper has reviewed experience in Belgium with 99 patients on CAPD. They represent 6-7% of all dialysis patients in this country. The principle reasons for selecting CAPD were old age, problems with vascular access and major cardiovas cular complications. Hemoglobin and hematrocrit values increased in all patients but preliminary measurements of red cell volume in some of them showed no change. Most patients showed moderate increases in serum triglycerides. In three non-diabetic patients with marked elevation in triglyceride levels, insulin, given intraperitoneally, prevented further increases. The frequency of peritonitis was still high; the average rate was one episode every 7.6 patient months. Other major complications included hypotension, which improved after the substitution of dialysate with a higher sodium concentration, severe respiratory disease and gangrene of the legs. After a mean follow-up of seven months, the death rate was 18% and the rate of technical success was 70%. The fact that most of our patients were in the high-risk category should be kept in mind when comparing these results with those obtained with other modes of treatment. At the end of 1978, a total of 1195 patients with end-stage renal disease (ESRD) were treated on either home or hospital dialysis in Belgium. There were 50 dialysis centers for a total population of 9.8 million. Of these 1195 patients, only seven were treated with either continuous ambulatory peritoneal dialysis (2-4) or intermittent peritoneal dialysis. Since then and until July 1, 1980 the number of patients treated with CAPD in Belgium has increased to 99 and this paper describes our experience with these patients.

Erythrokinetic studies in hairy-cell leukaemia.

Erythrokinetics were studied in 29 patients with hairy-cell leukaemia. In all cases there was an increase in plasma volume, closely correlated to the size of the spleen, indicating that the true degree of anaemia can only be appreciated by red cell volume measurement. Moderately increased haemolysis was observed in most cases, which did not correlate with the spleen size. Simultaneous study of autologous and isologous red cell life-span suggested an extra-corpuscular mechanism for the haemolysis in most patients. A quantitative erythropoietic defect, either relative or absolute, was found in half the cases, without any qualitative defect. Only one case showed erythroid metaplasia of the spleen. Thus marrow failure appears to be largely responsible for the anaemia and granulocytopenia in hairy-cell leukaemia. A clear correlation was shown between the short-term prognosis after splenectomy and the degree of hypersplenism. However, long-term survival correlated chiefly with the degree of bone marrow failure, whether splenectomy had been carried out or not. The results indicate that isotope studies in hairy-cell leukaemia are useful both in determining the best form of treatment and predicting survival.

A reassessment of intravascular volume measurements in protein—calorie malnutrition

Accurate determination of plasma volume is difficult in oedematous protein--calorie malnutrition, but present studies on the equilibrium of labelled red cells have shown that red cell volume measurements are valid in this syndrome. The red cell volumes have been measured in afflicted Bantu children during a refeeding programme. Expression of the results in ml/kg, ml/m2 or ml/cm is misleading and has been replaced by expressing the results as a percentage of the means of the normal values for the height. The results show that the red cell volume increase that ought to occur at the end of refeeding programme (and hence the iron requirement) is far higher than suggested by the packed cell volume. With treatment the red cell volume increases slowly. The red cell volume and plasma volume changes that occur during treatment do not take place at the same rate.

THE ASSESSMENT OF ANEMIA IN SMALL PREMATURE INFANTS

Changes in hemoglobin concentration in premature infants are difficult to interpret because of variations in blood volume and blood loss. We have determined circulating red cell volume (RCV) and erythrocyte survival by Cr51 red cell labelling using capillary techniques. In six infants whose weights varied from 680-1, 320 g, RCV was 29.5 ± 6.4 ml/kg. In these babies, blood lost for laboratory tests during the first three weeks of life averaged 0.81 ml/kg/day. In addition all materials contaminated by blood (sponges, syringes, etc.) were collected and the content of Cr51 labelled cells was determined. A correlation was found (r=0.60; p<0.01) between the amount of blood taken for tests and that in contaminated materials (0.08 ml/kg/day). The assessment of erythrocyte survival and of changes in hemoglobin concentration demands quantitation of blood lost through sampling. This, together with direct measurement of RCV permits a more complete evaluation of anemia in small premature infants.

Red cell volume measurements and acute blood loss in high-risk newborn infants

Red cell volume was measured in 259 infants admitted to a high-risk newborn unit. Red cell volume was measured using 50Cr tagging which subsequently was activated to 51Cr for counting. Total blood volume was calculated using the corrected whole body hematocrit. A low red cell volume was frequently associated with a maternal history of vaginal spotting, with placenta previa or placenta abruptio, with nonelective cesarean section, and with deliveries associated with cord compression. Asphyxiated infants without a history suggestive of blood loos often had a low red cell volume. An early central hematocrit below 45% correlated with a low red cell volume, but a normal or high hematocrit was often associated with low red cell measurements. The total blood volume depended largely on whether the tagging was done long enough after the blood loss for plasma volume equilibration to have occurred. Very low red cell volume values were associated with a high mortality rate, but birth weight played a dominant role in survival, even at low red cell volume levels.

Serum proteins, blood and plasma volumes in experimental Trypanosoma vivax infections of sheep and goats.

Measurements of blood and plasma volumes using 131I-albumin, and of red cell volume using 51Cr in goats and sheep infected with Trypanosoma vivax for 1 to 2 months (at which time the anaemia was severe) showed statistically significant increases in blood volume (29 per cent and 57 per cent) and plasma volume (44 per cent and 59 per cent), and decreases in red cell volume per kilogram body weight (49 per cent and 50 per cent) in goats and sheep respectively. Total serum proteins and gamma globulins increased, while serum albumin decreased, in T. vivax infected sheep and goats. These findings indicate that the anaemia manifested, with mean packed cell volume decreased by 60 per cent and 47 per cent in goats and sheep respectively at the time of red cell volume measurements, is attributable partly to haemodilution and partly to an actual decrease in total volume oc circulating red blood cells.

Erythrocytosis associated with diffuse parenchymal lesions of the kidney.

Thirteen patients with diffuse parenchymal disease of the kidney and erythrocytosis are reported. In five the haematocrit was only minimally elevated because of an associated increase in plasma volume. The erythrocytosis in three patients was of particular interest: (1) transient appearance in a 23-year-old man with glomerulonephritis; (2) persistence despite the partial remission of nephrotic state in a 19-year-old man; (3) appearance following removal of a nephrosclerotic kidney from a 54-year-old woman. Because an associated expansion of plasma volume is not uncommon with parenchymal renal disease, it is suggested that the only reliable screening method for renal erythrocytosis is direct measurement of red cell volume.

Assessment of acute blood-loss by determination of change in red-cell volume.

Abstract A method is described for the quantitative measurement of acute blood-loss from any source by determination of change in the red-cell volume. The accuracy and sensitivity of this method have been assessed in 23 patients admitted to hospital with acute gastro-intestinal bleeding. The method was sufficiently sensitive to detect a change in red-cell volume of 3 per cent. Reproducible results were obtained, duplicate measurements of red-cell volume deviating from the mean by less than 4 per cent. Completely separate daily measurements, in subjects not undergoing further haemorrhage, deviated from the mean by less than 5 per cent.

Critical evaluation of methods for determination of blood volume in the dog.

In 7 mongrel dogs a total of 202 measurements of blood volume were performed according to three different methods (RIHSA, Cr51, double-isotope method). Careful weighing of tracers and samples proved to be essential for correct measurements. Large vessel hematocrit values obtained by centrifugation and by the distribution of RIHSA in whole blood and in plasma were essentially equal. The disappearance rate of RIHSA averaged 10% per hour, while that of Cr51 differed significantly between dogs with and without saline infusion (20.9 and 13.7% per hour respectively). Values of blood volume for the fasting conscious dog averaged 80 ml/kg of BW with no significant difference between the three methods of determination. The correlation between blood volumes obtained by synchronized determination with Cr51 and RIHSA was rather weak (r=0.7143, standard deviation of the mean error ±14.3%). In agreement with this, the rate offcells showed a large scatter of ±7 and ±10% respectively for the two groups. It was demonstrated that the decrease of activity of Cr51 in the circulating blood due to the uptake of tagged red cells by the spleen is not linear, as initially supposed, but follows an exponential function, resulting in an error in the measurement of red cell volume of +10 and +13% respectively.

Erythrocyte 2,3-diphosphoglycerate in adaptive red-cell-volume deficiency.

Measurement of red-cell volume, plasma volume and erythrocyte 2,3-diphosphoglycerate (2,3-DPG) in five patients with panhypopituitarism and one patient with isolated growth-hormone deficiency revealed marked decrease in the red-cell volume and plasma volume but no increase in the red-cell 2,3-DPG. The same studies performed in two hypophysectomized monkeys gave similar results. Administration of combined human growth hormone and thyroxine to one of the patients and to hypophysectomized monkeys resulted in increases of 45 to 88 per cent in 2,3-DPG within five weeks. The hormonal therapy also restored red-cell volume to normal. Further studies revealed that these calorigenic hormones acted synergetically to increase the concentration of erythrocyte 2,3-DPG. The findings suggest that the level of erythrocyte 2,3-DPG may be a useful guide to differentiate an "adaptive" from pathologic deficiency in red-cell mass.

Survival of red cells.

Survival of red cells.

PLASMA AND RED CELL VOLUME AFTER PROLONGED SEVERE EXERCISE.

On six subjects plasma volume (Evans blue space) was determined before and 1 hr after an 85-km race in cross-country skiing. The total water loss during the 5- to 9.5-hr competition was estimated to be 5.9 liters, and at the time of measuring the reduction in body weight was 3.9 kg or 5.5% of the weight. The plasma volume was increased 0.41 or 11% (0.01 &gt; P &gt; 0.001). A similar study was undertaken with measurements of red cell volume (Cr51) on five subjects. The decrease in red cell volume was 0.081 or 3.2%. These findings are discussed in light of the small reduction in aerobic work capacity in combination with a marked decrease in total work output after the race. In five workers in a steel mill (three at a hot bank and two at a smelting furnace) the total water loss during an 8-hr shift in a hot environment was 3.9 liters and the reduction in body weight was 1.1 kg or 1.9% of the weight. The blood volume (I131) was increased by 0.23 liters or 3.5%. dehydration; blood volume Submitted on October 16, 1963

Epinephrineinduced hemoconcentration in the domestic hen.

The effect of 150 µg/kg epinephrine intravenously on the packed cell volume (PCV) was studied in 24 laying hens. The PCV was observed to rise to a peak between 20 and 30 minutes after injection and to gradually return to the preinjection level after 1–2 hours. T-1824 disappearance curve analysis, repeated plasma volume determinations and direct red cell volume measurements, using Cr51-tagged red cells, substantiate the conclusion that the response is due to loss of fluid from the vascular system with resultant concentration of the erythrocytes already present. The possible relationship of the pressor effect of epinephrine and of the role of the kidney to the response is considered.

Blood volume studies in wounded animals.

When severe macerating wounds of the thigh were produced in goats by high explosive the decrease in measurable blood volume could not be accounted for by external blood loss. Transfusions of red blood cells did not increase the circulating red cell volume by the amount transfused. It appears that red cells are extravasated, and once extravasated, they are then destroyed. The hemoglobin of the lost red cells is only gradually disposed of as bilirubin, which suggests that there may be a limit to the rate at which hemoglobin can be degraded. Serial measurements of red cell volume in unwounded animals indicated that transfusion in excess of the normal red cell volume results in the loss of circulating red cells. These lost cells may also be extravasated. Submitted on February 21, 1957

Precision of red cell volume measurement using 32P-labelled cells.

Precision of red cell volume measurement using 32P-labelled cells.