scholarly journals Correction and reporting of potassium results in haemolysed samples

Author(s):  
Goce Dimeski ◽  
Alan E Clague ◽  
Peter E Hickman

Background: Potassium is usually the most important analyte affected by in vitro haemolysis and the result obtained may falsely indicate or disguise a life-threatening abnormality and so give rise to inappropriate treatment. The purpose of the study was to provide a solution to the problem of reporting potassium on haemolysed samples, taking into account both clinical needs and analytical concerns (inter-individual and inter-sample variability). Methods: Using a new procedure that mimics the collection process in an actual clinical setting, haemolysed samples were prepared from 41 volunteers with a range of inter-individual factors - haemoglobin 80-173 g/L, red blood cells 2.42-6.77 x 1012/L, leucocytes 3.0-306 x 109 /L and platelets 31-710 x 109/L - in order to develop a more accurate correction equation using a haemolytic index (HI) corresponding to g Hb/L in plasma. Results: The mean (range) potassium increase was 0.0036 mmol/L (0.0029-0.0053 mmol/L) per unit HI. The following equation was developed to estimate potassium increase per HI, in order to compensate approximately for potassium leakage in haemolysed samples: Corrected K+=Measured K+ -(HI x 0.004). Conclusion: The balanced solution is this: instead of reporting the post-haemolysis corrected potassium result a qualitative comment is given, indicating the likely range of the potassium concentration. If the potassium result is in a critically low or high range, it is communicated promptly to the requesting clinician.

PEDIATRICS ◽  
1973 ◽  
Vol 51 (2) ◽  
pp. 230-233
Author(s):  
Andrew A. Raubitschek ◽  
Alan S. Levin ◽  
Daniel P. Stites ◽  
Edward B. Shaw ◽  
H. Hugh Fudenberg

An 8-year-old boy with chronic granulomatous disease (CGD) was admitted in moribund condition with aspergillus pneumonia. Because of the gravity of the situation, normal granulocyte infusions were used as adjuncts to the more conventional antimicrobial therapy. White blood cells, derived from a total of 58 units of whole blood obtained by leukophoresis of the father, were given in two separate doses. The first dose, totaling 2.8 x 1010 granulocytes, was coincident with significant improvement, and the second, totaling 3.0 x 1010 granulocytes, was coincident with the onset of clinical improvement and interim recovery. Transient improvement in in vitro granulocyte function was noted in cells taken from the patient's blood immediately after infusion. No adverse effects of the infusions were noted in either the patient or the donor. Although it is impossible to divorce the therapeutic effect of the granulocyte infusions from the more conventional therapy, we conclude that normal granulocyte infusions can be considered a valid adjunct in children with CGD who are suffering from a life-threatening infection.


1987 ◽  
Vol 73 (5) ◽  
pp. 557-560 ◽  
Author(s):  
David R. James ◽  
David Stansbie

1. Mechanisms responsible for increased erythrocyte K+ efflux in vitro have been investigated in a patient with familial pseudohyperkalaemia. Mean net K+ efflux (4°C) was 108 nmol h−1 10−9 erythrocytes, seven times greater than the mean for controls (15.2 nmol h−1 10−9 erythrocytes). Net K+ efflux was not increased at 22°C or 37°C and losses at 4°C were reversed by subsequent incubation at 37°C. 2. Erythrocyte glucose consumption (4°C) was 14 nmol h−1 10−9 erythrocytes, similar to the mean for controls of 16.8 nmol h−1 10−9 erythrocytes. This suggests that the increased net K+ efflux (4°C) was not associated with abnormal energy consumption and was therefore unlikely to be due to an abnormality of the Na+, K+-pump. 3. Incubation of erythrocyte suspensions with ouabain (0.1 mmol/l) or frusemide (1 mmol/l) at 4°C or 37°C resulted in no differences in K+ efflux between patient and controls. Incubation with quinine (2 mmol/l), an inhibitor of the erythrocyte Ca2+-dependent K+ channel, reduced net K+ efflux at 4°C, but the effect persisted in Ca2+-depleted erythrocytes, implying that quinine was acting in a non-specific fashion. 4. Chemical pathologists and clinicians must be aware of this condition if inappropriate treatment of pseudohyperkalaemia is to be avoided.


1957 ◽  
Vol 48 (4) ◽  
pp. 433-437 ◽  
Author(s):  
John V. Evans ◽  
M. S. Mounib

The concentrations of potassium in the whole blood of representative samples of sixteen British breeds of sheep have been studied.The proportion of sheep with a high level of potassium in the whole blood (high potassium or HK type) was found to differ significantly between breeds. It ranged from 0% in the English Leicester to 73% in the Rough Fell.There were significant differences between breeds in the mean concentration of potassium in the whole blood of both the LK and HK sheep.


Perfusion ◽  
1994 ◽  
Vol 9 (1) ◽  
pp. 35-40 ◽  
Author(s):  
Per Bergman ◽  
Ali Belboul ◽  
Lars Göran Friberg ◽  
Najib Al-Khaja ◽  
Gösta Mellgren ◽  
...  

Preserving the rheological properties of whole blood cells is vital for their smooth passage in the capillaries without causing blockage and disturbances in the microcirculation. To evaluate the effect of mechanical trauma on the rheology of white blood cells during prolonged perfusion with membrane oxygenation (PPMO), 16 in vitro experiments were conducted for 72 hours. The St George Carrimed Filtrometer was used to estimate the plasma white cell filtration rates (P-WFR). Also an in vitro estimation of the ability of individual cells to pass through capillaries, the white blood cell clogging rate (WBC-CR), the number of clogging particles (WBC-CP), the total white blood cell count (T-WBC) and two in vitro estimations to assess the effect of aggregates and stiff cells in blocking the microcirculation were performed. The traumatized white cells reduced their mean P-WFR by 37% ± 9, 72% ± 2 and 76% ± 2 at 24, 48 and 72 hours respectively (p < 0.001). The mean WBC-CR was increased to 15.2 ± 1.5, 32.6 ± 2.2 and 40.3 ± 8.3 x 102%/ml at 24, 48 and 72 hours respectively (p < 0.001). The mean WBC-CP was increased to 6.6 ± 1.5, 9.7 ± 1.2 and 13.9 ± 2.1 x 106/ml at 24 hours (p < 0.05), 48 and 72 hours respectively (p < 0.001). The T-WBC was decreased to 55% ± 0.3, 23% ± 0.2 and 14% ± 0.1 at 24,48 and 72 hours respectively (p < 0.001). This study showed a serious loss in white cell rheology during PPMO, which may contribute to the plugging effect of the microvessels in clinical use and may explain the organ dysfunction seen during ECMO on the basis of inadequate tissue oxygenation and nutrition due to areas of reduced perfusion, which results in increased frequency of morbidity.


1960 ◽  
Vol 199 (6) ◽  
pp. 1174-1176 ◽  
Author(s):  
Jack N. Blechner

Sodium and potassium concentrations in the erythrocytes of adult and fetal goats were estimated by flame photometry. In the fetus there is a higher potassium and a lower sodium concentration than in the adult. The mean fetal potassium concentration is 104.8 mEq/l. of red cells and the sodium 15.8; the maternal values are 68.4 and 35.4, respectively. Pregnancy does not appear to alter the sodium and potassium concentrations in adult goat erythrocytes. Moreover, the fetal levels show no change with advancing gestation, from the 52nd to the 142nd day. The sodium and potassium gradients between the red blood cells and the plasma in fetal blood are higher than in maternal blood and suggest the possibility of an increased energy expenditure by fetal erythrocytes. The findings lend support to the hypothesis that the ionic environment within the red cell is one of the factors contributing to the differences between the oxygen dissociation curves of fetal and maternal whole blood.


Blood ◽  
1968 ◽  
Vol 31 (5) ◽  
pp. 653-672 ◽  
Author(s):  
DEAN BUCKNER ◽  
ROBERT EISEL ◽  
SEYMOUR PERRY

Abstract A closed continuous flow centrifuge was used to separate and collect large quantities of buffy coat cells from the dog. One hundred fifty-five separate centrifugations of 2-12 hours duration were performed. Up to 61.0 liters of blood, representing 2.2-52 donor blood volumes, were processed. Buffy coat cells with a preponderance of granulocytes or lymphocytes, were collected while plasma and red blood cells were returned to the donor without change in flow or gravitational field. The mean total number of leukocytes, granulocytes, mononuclear cells and platelets removed was 24.0, 17.0, 7.0 and 197.0 x 10,9 respectively, which was 34.0, 28.0, 66.0 and 36.0 percent, respectively, of each cell population entering the centrifuge. The effect of centrifugation on blood components was evaluated. Granulocytes from buffy coat collections exhibited normal phagocytic ability in vitro. The transfusion of large quantities of granulocytes (15.0 x 109) into leukopenic dogs produced an increment in peripheral granulocyte count (2.7 x 103 per mm.3). Granulocytes labeled with 3H-DFP were also infused with a recovery of 38.6 percent at one hour and a T-½ of 4-6 hours. Machine-separated lymphocytes responded normally to phytohemagglutinin. Prolonged passage of blood through the pumps, tubing and bowl without centrifugation resulted in a decrease in circulating platelet levels (21 percent). A greater decrease in platelets occurred with centrifugation at high g. forces (49 percent). Hemolysis of red blood cells was not a serious problem.


2018 ◽  
Vol 46 (06) ◽  
pp. 399-402 ◽  
Author(s):  
Ayse Cakmak ◽  
Kader Yildiz ◽  
Neslihan Sursal

Summary Objective: Some studies have performed in vitro neutrophil isolation from feline blood. The major limiting factor for these studies is the small volume of blood that can be collected without development of potentially life-threatening complications. In the present study we attempted neutrophil isolation from feline venous blood samples using discontinuous Percoll gradients. Material and methods: Blood was collected from the cephalic vein of clinically healthy adult cats. The blood samples were layered on Percoll dilutions (72 %, 63 %, 54 % and 45 %). After centrifugation, the feline polymorphonuclear leukocytes (PMN) accumulated as a band between 72–63 % Percoll dilutions. The total cell count was calculated using light microscopy counts. The percentage of the neutrophils was determined microscopically after staining with Diff-Quik stain. Neutrophil viability was evaluated with a 0.01 % Trypan blue assay. The activation was determined based on intact cell morphology in the isolated neutrophils. Results: The mean PMN number was 22 x 105 per ml (minimum – maximum: 20–26 x 105/ml). Neutrophil homogeneity was > 95 % in the cell suspensions. The viability of isolated neutrophils was > 98 %. The technique did not result in neutrophil activation. Conclusion and clinical relevance: Discontinuous Percoll gradients (72 %, 63 %, 54 % and 45 %) can be used to isolate neutrophils from blood samples of cats. The technique was simple to perform and neutrophil activation was minimal.


1979 ◽  
Vol 47 (1) ◽  
pp. 67-71 ◽  
Author(s):  
G. H. Gurtner ◽  
R. J. Traystman

Five anesthetized dogs were made severely hypercapnic by stepwise addition of CO2 to their inspired air. Blood PCO2 levels greater than 400 Torr were reached. During hypercapnia, the steady-state end-tidal PCO2 (PaCO2) was always higher than the simultaneous measured arterial PCO2 (PaCO2). The mean ratio PaCO2/PACO2 was 0.861 +/- 0.01. These results are consistent with the predictions of the Charged Membrane Hypothesis, that gas-to-blood PCO2 differences should be directly proportional to the blood H+ activity. The results cannot be explained by delayed equilibration of CO2 between plasma and red blood cells. The latter hypothesis predicts that, under the conditions of these experiments, the PCO2 of arterial blood should be higher than the PCO2 of end-tibal gas. The blood HCO3- during hypercapnia did not increase as much as would be predicted if the blood were exposed to CO2 in vitro. This may reflect movement of blood HCO3- generated by the buffering of carbonic acid into intracellular compartments during hypercapnia.


Author(s):  
D.J.P. Ferguson ◽  
A.R. Berendt ◽  
J. Tansey ◽  
K. Marsh ◽  
C.I. Newbold

In human malaria, the most serious clinical manifestation is cerebral malaria (CM) due to infection with Plasmodium falciparum. The pathology of CM is thought to relate to the fact that red blood cells containing mature forms of the parasite (PRBC) cytoadhere or sequester to post capillary venules of various tissues including the brain. This in vivo phenomenon has been studied in vitro by examining the cytoadherence of PRBCs to various cell types and purified proteins. To date, three Ijiost receptor molecules have been identified; CD36, ICAM-1 and thrombospondin. The specific changes in the PRBC membrane which mediate cytoadherence are less well understood, but they include the sub-membranous deposition of electron-dense material resulting in surface deformations called knobs. Knobs were thought to be essential for cytoadherence, lput recent work has shown that certain knob-negative (K-) lines can cytoadhere. In the present study, we have used electron microscopy to re-examine the interactions between K+ PRBCs and both C32 amelanotic melanoma cells and human umbilical vein endothelial cells (HUVEC).We confirm previous data demonstrating that C32 cells possess numerous microvilli which adhere to the PRBC, mainly via the knobs (Fig. 1). In contrast, the HUVEC were relatively smooth and the PRBCs appeared partially flattened onto the cell surface (Fig. 2). Furthermore, many of the PRBCs exhibited an invagination of the limiting membrane in the attachment zone, often containing a cytoplasmic process from the endothelial cell (Fig. 2).


1993 ◽  
Vol 70 (04) ◽  
pp. 676-680 ◽  
Author(s):  
H F Kotzé ◽  
V van Wyk ◽  
P N Badenhorst ◽  
A du P Heyns ◽  
J P Roodt ◽  
...  

SummaryPlatelets were isolated from blood of baboons and treated with neuraminidase to remove platelet membrane sialic acid, a process which artificially ages the platelets. The platelets were then labelled with 111In and their mean life span, in vivo distribution and sites of Sequestration were measured. The effect of removal of sialic acid on the attachment of immunoglobulin to platelets were investigated and related to the Sequestration of the platelets by the spleen, liver, and bone marrow. Removal of sialic acid by neuraminidase did not affect the aggregation of platelets by agonists in vitro, nor their sites of Sequestration. The removal of 0.51 (median, range 0.01 to 2.10) nmol sialic acid/108 platelets shortened their life span by 75 h (median, range 0 to 132) h (n = 19, p <0.001), and there was an exponential correlation between the shortening of the mean platelet life span and the amount of sialic acid removed. The increase in platelet-associated IgG was 0.112 (median, range 0.007 to 0.309) fg/platelet (n = 25, p <0.001) after 0.79 (median, range 0.00 to 6.70) nmol sialic acid/108 platelets was removed (p <0.001). There was an exponential correlation between the shortening of mean platelet life span after the removal of sialic acid and the increase in platelet-associated IgG. The results suggest that platelet membrane sialic acid influences ageing of circulating platelets, and that the loss of sialic acid may have exposed a senescent cell antigen that binds IgG on the platelet membrane. The antibody-antigen complex may then provide a signal to the macrophages that the platelet is old, and can be phagocytosed and destroyed.


Sign in / Sign up

Export Citation Format

Share Document