Academic literature on the topic 'Haematocrit concentration'
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Journal articles on the topic "Haematocrit concentration"
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Noera, G., C. Massini, and G. Baggio. "In vitro plasma nifedipine concentration during heart-lung machine function." Perfusion 2, no. 4 (October 1987): 277–81. http://dx.doi.org/10.1177/026765918700200406.
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The use of calcium antagonists such as nifedipine for myocardial protection during cardiac surgery has been advocated by several authors. During extracorporeal circulation many factors, such as light, interaction with circuit materials and haematocrit, may contribute to decrease plasma clearance of calcium antagonists In an in vitro model of a heart-lung machine, plasma nifedipine and prime concentrations were detected with a series of samples at different temperatures (25 °C and 37 °C), haematocrits (0%, 20%, 30% and 40%) and light conditions (light and dark). The results show a rapid drop of nifedipine concentration with a halflife of about 3-9 minutes and this situation is influenced with statistical significance by the presence of light and increased haematocrit. The knowledge of this condition is useful when nifedipine is used before/ during cardiopulmonary bypass and during cardioplegia and reperfusion infusion with the use of extracorporeal devices.
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Albers, G. A. A., G. D. Gray, L. F. Le Jambre, I. A. Barger, and J. S. F. Barker. "The effect of Haemonchus contortus infection on haematological parameters in young Merino sheep and its significance for productivity." Animal Science 50, no. 1 (February 1990): 99–109. http://dx.doi.org/10.1017/s0003356100004505.
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ABSTRACTFaecal egg counts, haematocrits, erythrocyte potassium contents and serum iron concentrations were determined in 1005, 3- to 5-month-old Merino lambs infected with a single dose of 11 000 Haemonchus contortus larvae. Live-weight gain and wool growth also were recorded. Lambs were infected in six different groups over a 3-year period. When infections were terminated after 5 weeks, faecal egg counts in the six infected groups had reached a peak of 5170 to 20 339 eggs per g (average 12 909), haematocrits had declined to between 196 and 309 ml/1 (average 233), erythrocyte potassium contents had risen to between 16·7 and 37·5 mequiv. per 1 (average 31·5) and serum iron concentrations, in some cases following an erratic course, had dropped to between 0·512 and 1·546 mg/1 (average 0·946).Of the three haematological parameters, haematocrit correlated best with faecal egg count (r = 0·7 in four of six infected groups). However, in two groups with low faecal egg counts this correlation was much lower (r = 0·3). Erythrocyte potassium concentration and serum iron concentration significantly correlated with variability of haematocrit not accounted for by faecal egg count, suggesting that both erythropoiesis and iron availability influence the degree of anaemia.The effect of H. contortus infection on productivity of lambs was best predicted by haematocrits: for each further 0·01 proportional decrease in haematocrit, a 0·03 reduction of live-weight gain over a 9-week post-infection period, a 0·007 reduction in clean wool growth and a 0·004 reduction in fibre diameter over a 4- to 9-week period were observed. Some evidence was obtained indicating a tolerance level of anaemia at approximately 280 ml/1 packed cell volume.
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Al-Hassan, L. A. J., A. Y. Al-Abood, and A. A. Al-Seyab. "Seasonal variations in the haemoglobin concentration and haematocrit values of Silurus triostegus." Acta Ichthyologica et Piscatoria 20, no. 1 (June 30, 1990): 99–103. http://dx.doi.org/10.3750/aip1990.20.1.08.
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Cleva, GM, GM Stone, and RK Dickens. "Seasonal-Changes in Hematocrit in Captive Koalas (Phascolarctos-Cinereus)." Australian Journal of Zoology 42, no. 2 (1994): 233. http://dx.doi.org/10.1071/zo9940233.
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Six males and nine females, members of a group of 15 captive koalas, were examined for changes in haematocrit for 22 and 11 months respectively. Plasma protein concentration and plasma osmolarity were also measured in samples that varied widely in haematocrit. Body weight was routinely recorded. In both sexes there were pronounced changes in microhaematocrit with time of year, with elevated values in winter and low values in summer. Microhaematocrit was thus significantly and negatively correlated with maximum and minimum daily temperature. These changes in haematocrit were not associated with changes in body weight, plasma protein concentration or plasma osmolarity. It is suggested that the higher winter haematocrit is a physiological adaptation to the higher energy demands when ambient temperature is reduced.
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Salis, Emma R., David M. Reith, Roland S. Broadbent, and Natalie J. Medlicott. "Haematocrit influences insulin concentration measurements in dried blood spots." Journal of Maternal-Fetal & Neonatal Medicine 29, no. 19 (December 23, 2015): 3208–11. http://dx.doi.org/10.3109/14767058.2015.1119116.
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Carter, A. J., and S. P. Hanley. "The Effect of Platelet Number and Haematocrit on Whole Blood Thromboxane Synthesis." Thrombosis and Haemostasis 53, no. 02 (1985): 225–27. http://dx.doi.org/10.1055/s-0038-1661280.
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SummaryWhole blood, allowed to clot at 37° C in glass tubes, synthesized thromboxane A2 (TxA2) as determined by radioimmunoassay for thromboxane B2 (TxB2). The time course for TxB2 synthesis showed no further increase after 60 min and the concentration of TxB2 in serum obtained from 60 normal subjects positively correlated with the whole blood platelet count in EDTA anticoagulated blood from the same donor.Patients with chronic renal failure produced less serum TxB2 than age- and sex-matched controls; they also had lower haematocrits. After re-calculating TxB2 production as a function of platelet count and haematocrit all but one of the patients fell in the range of values obtained for controls. These results suggest that chronic renal failure may not be associated with a cyclooxygenase defect and that clotted whole blood TxB2 production should be expressed as a function of platelet count and haematocrit.
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Perry, S. F., and K. Gilmour. "AN EVALUATION OF FACTORS LIMITING CARBON DIOXIDE EXCRETION BY TROUT RED BLOOD CELLS IN VITRO." Journal of Experimental Biology 180, no. 1 (July 1, 1993): 39–54. http://dx.doi.org/10.1242/jeb.180.1.39.
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An evaluation of several potential factors limiting carbon dioxide excretion by rainbow trout (Oncorhynchus mykiss) red blood cells was performed in vitro using a recently developed radioisotopic assay. Red blood cell (RBC) CO2 excretion was reduced by pre-treatment (30 min) of blood with the carbonic anhydrase inhibitor acetazolamide (final nominal concentration 10–4 mol l-1) or the Cl-/HCO3- exchange inhibitor SITS (4-acetamido-4′-isothiocyanatostilbene-2,2′-disulphonic acid; 10-4 mol l-1). The addition of bovine carbonic anhydrase to plasma stimulated CO2 excretion in a dose-dependent manner, with maximal levels of CO2 excretion achieved at a concentration of 3 mg ml-1. These results confirmed that carbonic anhydrase activity and/or Cl-/HCO3- exchange velocity are potential limiting factors in CO2 excretion. Increasing the haematocrit elevated the rate of RBC CO2 excretion, although the effect was apparent only between 0 and 15 % haematocrit; the rate of CO2 excretion was unaffected by further increases in haematocrit between 15 and 35 %. Acute elevation of plasma HCO3- levels increased the rate of CO2 excretion in blood but not in plasma (with or without added carbonic anhydrase). These data suggest that HCO3- availability may limit CO2 excretion at higher haematocrits when the Cl-/HCO3- exchange sites are most plentiful. Lysis of RBCs and the accompanying release of intracellular carbonic anhydrase into the plasma significantly increased CO2 excretion at all haematocrit and HCO3- levels, indicating that the velocity of Cl-/HCO3- exchange does indeed limit trout RBC CO2 excretion. The addition of carbonic anhydrase (3 mg ml-1) to lysed blood caused a further increase in the rate of CO2 excretion but only at the low haematocrit of 5 %. This result suggests that the activity of RBC carbonic anhydrase does not normally limit CO2 excretion except at unusually low haematocrits, such as might occur during severe anaemia. The rapid oxygenation of partially deoxygenated blood during the 3 min assay caused a marked stimulation of CO2 excretion that was concurrent with a significant decrease of RBC intracellular pH (pHi). These data indicate that the supply of Bohr protons during the oxygenation of the blood is a key factor limiting CO2 excretion. Oxygenation of the blood prior to performing the assay also lowered RBC pHi, although CO2 excretion was actually reduced, indicating a possible specific effect of pHi on Cl-/HCO3- exchange activity or HCO3- dehydration. The results are discussed with reference to the control of carbon dioxide excretion in fish.
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Lönnqvist, PA, and L. Herngren. "Effects of pronounced haemodilution on the plasma protein binding of lidocaine." Perfusion 10, no. 1 (January 1995): 17–20. http://dx.doi.org/10.1177/026765919501000104.
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The effects of pronounced haemodilution on the protein binding of lidocaine was investigated in vitro in plasma from five healthy adult volunteers. The plasma was diluted with a phosphate buffer to reach a plasma protein concentration normally seen during paediatric cardiopulmonary bypass (CPB) and protein binding was determined at a low (1.5 μg/ml) and a moderate (4 μg/ml) total plasma concentration of lidocaine. The effects of different haematocrits on plasma protein binding was also determined over the haematocrit range 20-60%. The binding of lidocaine was found to be inversely related to the degree of dilution, i.e. the free fraction increased significantly with increasing dilution (p < 0.0001). Furthermore, the binding was dependent on the total plasma concentration of lidocaine, since a significantly higher percentage of free drug was found at the higher total lidocaine level (4 μg/ml) compared with the lower level (1.5 μg/ml) (p < 0.05). No significant difference in the free fraction of lidocaine could be found over the studied haematocrit range. The results of the present study indicate that plasma protein levels commonly associated with CPB in neonates and infants are associated with a significant increase in the free, unbound and pharmacologically active fraction of lidocaine compared with normal conditions. The use of commonly recommended dosages of lidocaine might result in toxic-free concentration in this setting.
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Svetina, A., Željka Matašin, and Alenka Tofant. "Haematology and some blood chemical parameters of young carp till the age of three years." Acta Veterinaria Hungarica 50, no. 4 (October 1, 2002): 459–67. http://dx.doi.org/10.1556/avet.50.2002.4.8.
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Haematological and biochemical analyses of blood were performed in carp (Cyprinus carpio L.) kept in small ponds. Caught and anaesthetised carp were clinically examined and blood samples were taken at regular intervals during the three years. In the first year of examinations, the haemoglobin and haematocrit values of carp fry significantly increased (P<0.01) from June to September. The intensive growth of carp in the summer period in the second year was accompanied by adequate erythropoiesis. During hibernation haematocrit and haemoglobin significantly decreased (P<0.05) and mean corpuscular haemoglobin concentration (MCHC) increased (P<0.01) in both scaly and mirror carp. MCHC increased also with the age and increasing body weight of the fish. Mirror carp had lower haematocrit and haemoglobin values than scaly carp (P<0.01). Comparative haematological analyses between carp of normal and poor body condition showed that moderate anaemia appeared in those with poor body condition. The results indicate that there is marked seasonal and age-dependent variation in the values of haematocrit and haemoglobin. Pond water quality investigations indicated good environmental conditions. A 50% increase (P<0.05) of glucose concentration was found from June to September in the blood plasma of carp in the third year, accompanied by an even more increased (80%; P<0.01) concentration of total lipids. At the same time, considerable changes of cholesterol and total protein concentrations were not observed. The results suggest that the investigated haematological and biochemical variables could be successfully utilised in monitoring the metabolic balance and health status of fish in intensive culture.
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Parrott, R. F., S. N. Thornton, M. L. Forsling, and C. E. Delaney. "Endocrine and behavioural factors affecting water balance in sheep subjected to isolation stress." Journal of Endocrinology 112, no. 2 (February 1987): 305–10. http://dx.doi.org/10.1677/joe.0.1120305.
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ABSTRACT The effect of stress on drinking, water balance and endocrine profile was studied using ten castrated rams. Individual sheep were exposed to 30-h periods of total isolation (psychological stress) or physical separation from their social group (control). Plasma was analysed for haematocrit, osmolality, electrolyte levels and concentrations of cortisol and arginine vasopressin. Isolation stress significantly reduced water intake, increased haematocrit and plasma concentration of cortisol, but did not alter osmolality or vasopressin concentration. The physiological effects of this self-imposed water restriction contrast with those obtained by depriving the sheep of water for 24 h under conditions that were not stressful, i.e. by keeping them grouped together. These results suggest that cortisol may act to defend plasma volume in sheep exposed to acute stress. The results also indicate that vasopressin probably should not be considered to be a 'stress hormone' in the sheep. J. Endocr. (1987) 112, 305–310
Dissertations / Theses on the topic "Haematocrit concentration"
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Deng, Linhong. "Electrical and rheological properties of blood and haemorheometry." Thesis, University of Strathclyde, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.248773.
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Gordon, Christopher, and res cand@acu edu au. "Hydrostatic and thermal influences on intravascular volume determination during immersion: quantification of the f-cell ratio." Australian Catholic University. School of Exercise Science, 2001. http://dlibrary.acu.edu.au/digitaltheses/public/adt-acuvp4.14072005.
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Previous data have shown that the most prevalent, indirect plasma volume (PV) measurement technique, which utilises changes in haematocrit (Hct) and haemoglobin concentration ([Hb]), underestimates actual PV changes during immersion, when compared to a direct tracer-dilution method. An increase in the F-cell ratio (whole-body haematocrit (Hctw) to large-vessel haematocrit (Hctv) ratio) has been purported as a possible explanation, probably due to hydrostatic and thermally-mediated changes during water immersion. Previous investigators have not quantified the F-cell ratio during immersion. Therefore, this study sought to determine the effect of the F-cell ratio on the indirect method during both, thermoneutral and cold-water immersions. Seven healthy males were tested three times, seated upright in air (control: 21.2°C SD ±1.1), and during thermoneutral (34.5oC SD ±0.2) and cold-water immersion (18.6oC SD ±0.2), immersed to the third intercostal space for 60 min. Measurements during the immersion tests included PV (Evans blue dye column elution, Evans blue dye computer programme, and Hct [Hb]), red cell volume (RCV; sodium radiochromate), cardiac frequency (fc) and rectal temperature (Tre). Plasma volume during the control trial remained stable, and equivalent across the three tests. There was a hydrostatically-induced increase in PV during thermoneutral immersion, when determined by the Evans blue dye method (16.2%). However, the Hct/[Hb] calculation did not adequately reflect this change, and underestimated the relative PV change by 43%. In contrast, PV decreased during cold immersion when determined using the Evans blue dye method by 17.9% and the Hct/[Hb] calculation by 8.0%, respectively, representing a 52% underestimation by the latter method. There was a non-significant decline in RCV during both immersions. Furthermore, an increase (8.6%) and decrease (-14.4%) in blood volume (BV) was observed during thermoneutral and cold-water immersions, respectively. The decline in RCV during thermoneutral immersion attenuated the BV expansion. Despite the disparity between the PV methods, there was no increase in the F-cell ratio during either immersion. In contrast, there was a significant decline in the F-cell ratio during the control: air and thermoneutral immersion, which may indicate that other, undefined variables may impact on the stability of the red cell compartment. The current study is the first to show that the Hct/[Hb] method clearly underestimates PV changes during both thermoneutral and cold-water immersion. Furthermore, RCV was shown, for the first time, to decline during both immersions. However, the changes in the F-cell ratio during this study, did not account for the underestimation of PV change using the Hct/[Hb] method.
Book chapters on the topic "Haematocrit concentration"
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Ciurea, Stefan O., and Ronald Hoffman. "The polycythaemias." In Oxford Textbook of Medicine, 4264–74. Oxford University Press, 2010. http://dx.doi.org/10.1093/med/9780199204854.003.220308.
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Polycythaemia or erythrocytosis is characterized by an abnormal increase in the numbers of red blood cells, leading to an elevation in the haemoglobin concentration and haematocrit (>52% in men and >48% in women). The cause may be either (1) primary—due to an intrinsic defect of haemopoietic stem cells; or (2) secondary—due to extrinsic stimulation of progenitor erythroid cells by circulating growth factors; and the condition needs to be distinguished from (3) pseudopolycythaemia—in which haematocrit is raised because the plasma volume is decreased....
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Perry, David J., and Katharine Lowndes. "Blood disorders specific to pregnancy." In Oxford Textbook of Medicine, 2173–80. Oxford University Press, 2010. http://dx.doi.org/10.1093/med/9780199204854.003.1416.
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Plasma volume increases by more during pregnancy than does red cell mass, leading to haemodilution and a fall in the haematocrit from about 40% to 33%, with the nadir usually reached at 24 to 32 weeks gestation. Anaemia during pregnancy is defined as a haemoglobin concentration of <10.5 g/dl during the second and third trimesters....
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Aruch, Daniel, and Ronald Hoffman. "The polycythaemias." In Oxford Textbook of Medicine, edited by Chris Hatton and Deborah Hay, 5227–39. Oxford University Press, 2020. http://dx.doi.org/10.1093/med/9780198746690.003.0517.
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Polycythaemia or erythrocytosis is characterized by an abnormal increase in the numbers of red blood cells, leading to an elevation in the haemoglobin concentration and haematocrit (>49% in men and >48% in women). The cause may be either (1) primary—due to an intrinsic defect of haematopoietic stem cells; or (2) secondary—due to extrinsic stimulation of progenitor erythroid cells by circulating growth factors; and the condition needs to be distinguished from (3) pseudopolycythaemia—in which haematocrit is raised because the plasma volume is decreased. Secondary polycythaemias: associated with appropriate erythropoietin secretion—conditions that are ultimately the result of tissue hypoxia and subsequent excessive erythropoietin production include (1) living at high altitude, (2) chronic lung disease, (3) cyanotic congenital heart disease with right-to-left shunting, (4) carbon monoxide intoxication—as occurs in heavy smokers, (5) haemoglobin variants with increased oxygen affinity, and (6) mutations in genes involved in the oxygen sensing pathway. Associated with inappropriate erythropoietin secretion—in the absence of tissue hypoxia, inappropriate erythropoietin production commonly originates from the kidney and many renal disorders are associated with erythrocytosis. Tumour-associated polycythaemia may also result from cerebellar haemangioblastoma, hepatocellular carcinoma, phaeochromocytoma, and other adrenal tumours. Primary polycythaemia: polycythaemia vera—is a clonal, chronic progressive haematological malignancy characterized by excessive proliferation of erythroid, myeloid, and megakaryocytic elements in the bone marrow. Aetiology—up to 95% of cases are caused by somatic mutations in the pluripotent haemopoietic stem cells leading to replacement of a key valine residue by phenylalanine at position 617 of the JAK2 kinase (V617F), which releases it from autoinhibition. Less common mutations have been described recently, primarily JAK2 exon 12 and LNK mutations.
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Perry, David J., and Katharine Lowndes. "Blood disorders in pregnancy." In Oxford Textbook of Medicine, edited by Catherine Nelson-Piercy, 2687–95. Oxford University Press, 2020. http://dx.doi.org/10.1093/med/9780198746690.003.0279.
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Plasma volume increases by more during pregnancy than does red cell mass, leading to haemodilution and a fall in the haematocrit from about 40% to 33%, with a nadir usually reached at 24–32 weeks’ gestation. Anaemia during pregnancy is defined as a haemoglobin concentration of below 105 g/L during the second and third trimesters and below 110 g/L in the first trimester. The commonest haematological problem encountered in pregnancy is iron-deficiency anaemia. Routine iron supplementation in all pregnant women is probably not justified in developed countries, but if iron deficiency is detected it is advisable to treat as early as possible. Normal pregnancy is associated with marked changes in all aspects of haemostasis, the overall effect of which is to generate a state of hypercoagulability. These changes in haemostasis, while reducing the risks of excessive blood loss at delivery, significantly increase the risk of venous thromboembolic disease in pregnancy.
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Emmett, Stevan R., Nicola Hill, and Federico Dajas-Bailador. "Non- malignant haematology and allergy." In Clinical Pharmacology for Prescribing. Oxford University Press, 2019. http://dx.doi.org/10.1093/oso/9780199694938.003.0020.
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Anaemia is very common, affecting over one- third of the world’s population and can be defined as a reduction in the haemoglobin content of red blood cells (RBC). The normal range varies slightly according to the population being tested, but typically in the UK anaemia in males can be diagnosed if the haemoglobin falls to below 135 g/ L and in females below 115 g/ L. In addition to a reduction in the haemoglobin concentration there is usually an associated reduction in the number of circulating red cells and a low haematocrit. Anaemia is not a diagnosis, it is an abnormality that has an underlying cause and, therefore, a determination of that cause must be made before effective treatment can begin. The production of red cells is termed ‘haematopoiesis’ and occurs in the bone marrow (liver and spleen in foetal life). The bones involved in production change as we age from almost all bones in neonates to long bones, pelvis, and thoracic cage when we reach our 4th decade. As with all blood cells, production of RBCs begins with a pluripotent stem cell that is capable of forming many progenitor cells, including those of the erythroid (red cell) lineage (Figure 12.1). It is estimated that a single pluripotent stem cell, following 18– 20 successful divisions, is able to produce 10 million mature erythrocytes. For this process to occur a number of growth factors (GF) are required, which act in synergy and enable the process of haematopoiesis to follow a stepwise maturation process, ending in the release of mature erythrocytes into the blood stream. Examples of such factors include the interleukins (IL), i.e. IL- 1, IL- 3, IL- 4, IL- 5, and IL- 6. Growth factors also act on the bone marrow stromal cells, enabling the correct environment for cell maturation and development. Tumour necrosis factor (TNF) and IL- 1 are particularly important stromal acting growth factors and can stimulate the stromal cells to produce many of the IL factors described above. The GF erythropoietin (EPO) is required for successful red cell maturation. Many of the growth factors work by binding to cell surface receptors.
Conference papers on the topic "Haematocrit concentration"
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Sonnet, J., and E. K. Gini. "IMPROVEMENT OF SICKLE CELL DEFORMABILITY BY PIRACETAM IN VITRO AND IN VIVO." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644214.
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Piracetam (P) (2-oxo-pyrrolidine acetamide) has Theological properties and has been used at various dosages over the past decade for the management of psychosenescent syndromes. On maintenance therapy, at the oral dosage of 160 mg/kg/day, in four divided doses, P reduces the number of vaso-occlusive crises in sickle cell homozygous patients, to about a fifth of what could be expected without drug. After oral intake at the latter dosage P's bioavailability in the blood ranges from 0.5to 1 m mol/1. Microsieving on polycarbonate filters, 5 μ m por size, of diluted suspensions (haematocrit 1%) of oxygenated HbSS cells previously incubated with P 0.5 to 1 m mol/1, shows that the drug strongly improves their deformabi1ity. Similarly, microsieving of oxygenated HbSS cells obtained from patients on maintenance therapy with P, shows that the drug enhances the deformabi 1 ity of these cells as actively as it does in in vitro experiments in the same range of concentration. On the other hand the drug only poorly restores the loss of deformabi 1 ity of physiologically deoxygenated HbSS cells. From these experiments, it seems that P works rather on the outer viscoelastic properties of the HbSS red cell membrane than on the inner HbSS content of these cells.
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Gordge, M. P., R. W. Faint, P. B. Rylance, and G. H. Neild. "THE BLEEDING TENDENCY OF PROGRESSIVE RENAL FAILURE IS NOT ASSOCIATED WITH DEFECTIVE PLATELET AGGREGATION." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644566.
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The bleeding tendency of uraemia may be related to reduction by anaemia of erythrocyte/platelet interaction, toxic inhibition of platelet aggregation and abnormal von Willebrand Factor (vWF) mediated platelet adhesion. Our aim in this study was to determine at what stage of renal failure bleeding time becomes prolonged and to investigate the mechanisms involved.We have measured bleeding time (Simplate II), plasma levels of fibrinogen and vWF, and ex-vivo platelet responsiveness in 31 patients with chronic renal failure (CRF) of various degrees of severity and compared them with values obtained in 22 healthy controls. No patient was dialysed, nephrotic or suffering from immunological renal disease. Patients were divided into mild (plasma creatinine <300 umol/1), n=10, moderate (300-600 umol/1), n=14, or severe (>600 umol/1), n=7, CRF.Bleeding time became significantly prolonged only in severe CRF (p<0.005). Haematocrit fell as renal failure advanced, and correlated with bleeding time (r=0.40, p<0.05). Platelet counts were normal. Platelet aggregation in response to ristocetin (mediated by vWF) and ADP increased progressively (p<0.005 in severe CRF), as did spontaneous aggregation (p<0.005 in severe CRF). This was associated with an increase in plasma vWF and fibrinogen (p<0.005 in severe CRF). Collagen induced aggregation was slightly, but not significantly increased. Thromboxane (TxB2) generation in clotting blood was the only measurement that showed a reduced platelet response (p<0.025 in severe CRF).In summary, a bleeding tendency develops late in the course of progressive CRF when plasma creatinine has risen to at least 600 umol/1. Platelet aggregation is enhanced rather than reduced and platelet interaction with vWF is not defective. Anaemia appears more important than abnormal platelet aggregation in mediating uraemic bleeding, although reduced serum TxB2 generation suggests a defect in platelet response to endogenous thrombin which may also contribute. Increased platelet aggregation and fibrinogen concentrations might promote glomerular thrombosis and contribute to the progression of CRF.
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Porte, R. J., E. A. R. Knot, O. T. Terpstra, and N. F. Rodriquez Erena. "MONITORING OF HAEMOSTASIS DURING AND AFTER EXPERIMENTAL AUXILIARY LIVERTRANSPLANTATION." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643182.
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Haemorrhagic diathesis is a major risk after human orthotopic livertransplantation. Theoretically, auxiliary livertransplan-tation (APLT) during which a partial livergraf t is inplanted next to the sick host-liver, should be acccnpanied with a minor haemo-rrhagic diathesis. In this study, haemostasis was monitored intensive during experimental APLT. Transplantation was performed in healthy pigs (n=6). There was no subtitutian of plasma products or platelet concentrates, nor use of heparin during the operation, thus making it possible to study the effect of the transplantation procedure and the (ischaemic) liver-graft only. Bloodsanples were taken just after induction of anaesthesia, after anastomosis of the Portal Vein, after anastomosis of the Hepatic Artery, 2 and 3 hours post-operative and several days after transplantation (max. follow-up 30 days). A sairple was also taken from the first blood outflow from the graft after recirculation. The following parameters were studied: APTT, PT, thrombintime, Normotest (R):, fibrinogen, AT-III, plasminogen, α2-AP, FDP's, platelet-oount and haematocrite. Sanples taken direct from the first blood outflow from the graft showed a decrease in platelet;-count and a prolongation of the APTT, PT and thrombintime, possibly indicating a oonsurrption of platelets and clotting factors in the graft. During operation there was a decrease of α2AP, AT-III and platelet-oount, while a remarkeble increase was seen during the first week after surgery to concentrations higher than the normal upper limit. At the end of the first week, in four animals an increase in APTT was seen (x=252%), together with a prolongation of the thrombintime ( 60 sec.). Because an anti-Xa activity was measurable, an endogenous heparin-like substance might be reponsible for this. None of the animals showed a bleeding tendency during or after transplantation, which indicates that the surgical procedure followed during APLT and the ischaemic graft do not give a serious disturbance of the haemostasis.