Association of haematocrit and red blood cell transfusion with outcomes in infants with shunt-dependent pulmonary blood flow and univentricular physiology

BackgroundThe aim of this study was to investigate the association between red blood cell (RBC) transfusion and haematocrit values with outcomes in infants with univentricular physiology undergoing surgery for a modified Blalock-Taussig shunt.ResultsSeventy-three patients qualified for inclusion. All study patients received blood transfusion within the first 48 hours after heart surgery. The median haematocrit was 44.3 (interquartile range [IQR] 42.5–46.2), and the median volume of RBC transfused was 28 mL/kg (IQR, 10–125) in the first 14 days after surgery. The overall in-hospital mortality rate was 13.6% (10 patients). A multivariable analysis adjusted for risk factors, including weight, prematurity, cardiopulmonary bypass and postoperative need for nitric oxide and dialysis, revealed no association between haematocrit values and RBC transfusion with the composite clinical outcome.DiscussionWe did not find an association between higher haematocrit values and increasing RBC transfusions with improved outcomes in infants with shunt-dependent pulmonary blood flow and univentricular physiology. The power of our study was small, which prevents any strong statement on this lack of association. Future multi-centre, randomised controlled trials are needed to investigate this topic in further detail.     

Autologous blood transfusion in elective heart surgery: prospective study of 189 consecutive patients

Blood autotransfusion has entered a new phase in blood transfusion technique, since it represents an important alternative in eliminating the risks connected with blood transfusion: viral hepatitis, AIDS, blood transfusion reactions, and alloimmunization. Transfusion requirements during cardiac surgical procedures have steadily decreased; nowadays most adult patients require no transfusion during surgery. Patients (pts) receiving bank-blood may develop infectious diseases (hepatitis, AIDS, etc.). We have studied how to avoid the risk of infections with homologous blood transfusions. We present our experience of day-hospital pre-operative autologous blood collection. One-hundred-eighty-nine patients undergoing primary myocardial revascularization or valvular replacement were submitted to the drainage of 350 ml of blood three times every four days before surgery. The blood was centrifuged at once, to separate red cells from plasma. Surgeries were performed 21 days after the first drainage; iron therapy was recommended. After surgery pts received blood only if haematocrit was lower than 28%. The following data were recorded: no. of pts who received homologous blood; blood loss and homologous total blood volume used for each pt. Average blood loss was 1230 cc for ischemic pts and 701 cc for valvular pts. Non-A non B hepatitis occurred in 3/189 pts (1.5%). All of them had received homologous blood transfusions. Our data show clearly that autotransfused pts had a better post-operative period; less bank-blood and fewer transfusions have been used. No pt had collateral effects such as angina or hypotension from blood drawing. Our data show that severe cardiac diseases do not represent an absolute contraindication to heavy blood drainage.(ABSTRACT TRUNCATED AT 250 WORDS)     

Risk factors for red cell transfusion in adults undergoing coronary artery bypass surgery: a systematic review

BACKGROUND AND OBJECTIVE: Identifying factors that can predict adults at high risk of receiving red blood cell transfusion during coronary artery bypass graft (CABG) surgery may aid in more efficient blood banking practices and may tailor blood conservation strategies for these adult patients. The objective was to identify clinical factors associated with increased red cell transfusion in adults undergoing CABG surgery. METHODS: A systematic review of the MEDLINE and HealthSTAR databases from 1966 to December 2005 was conducted. Citations containing the medical subject heading or textwords 'coronary artery bypass graft', 'CABG' and 'cardiovascular surgery' were combined with the medical subject headings or textwords 'transfusion' and 'blood transfusion'. RESULTS: A total of 2461 abstracts were retrieved. Twenty-one studies met the inclusion/exclusion criteria. Transfusion rates ranged from 7 to 97%. Several variables were identified that were associated with increased red cell transfusion rates including older age, female sex, low haemoglobin concentration or haematocrit value, renal insufficiency and urgent/emergent surgery. The strongest risk factor was the urgency of surgery (urgent or emergent surgery), which was associated with a 4x to 8x increase in transfusion rates compared to elective surgery. Increasing age and female sex increased the likelihood of transfusion by 1x to 3x and 2x, respectively. CONCLUSIONS: Increasing patient age, female sex, lower preoperative haemoglobin levels, as well as the urgency of the CABG surgery were associated with higher transfusion rates. Identifying risk factors for transfusion may allow for targeted use of blood conservation strategies, improved efficiency in blood utilization and informing adults at risk of transfusion.     

Spleen Size Changes in Children with Homozygous β-Thalassaemia in Relation to Blood Transfusion

18 thalassaemic children, aged 3.5 to 13 years comprise our clinical material. In 14 of them, clinically elicited spleen markings, haematocrit, blood platelet count and red cell morphology were studied daily for a whole period between 2 transfusions. In 10 patients considerable changes in spleen size were noticed. According to our clinical observations the spleen size starts decreasing 1 to 3 d after blood transfusion up to the 10th posttransfusion day fluctuating thereafter to reach its maximum size again prior to the next blood transfusion. The decrease of spleen size was followed by an increase of haematocrit and blood platelet count and vice versa. 4 additional children were studied clinically only twice: prior to and 7 to 10 d after blood transfusion. A definite decrease of the spleen size following blood transfusion was observed. Spleen and liver ^99mTc-sulfur colloid uptake was studied in 10 of the above children prior to and 7 to 10 d after blood transfusion. Statistically significant post-transfusion increase of the spleen uptake was demonstrated. Our findings suggest that (a) splenic size is relevant to blood volume sequestrated int this organ, (b) splenic radioactive uptake increases with its post-transfusion reduction in size.     

A revised rule of thumb for predicting haematocrit rise in premature infants following packed red blood cell transfusion

The purpose of this study is to compare a revised rule of thumb with the Harriet Lane and Behrman's formulas for predicting haematocrit rise following packed red blood cell (PRBC) transfusion in premature neonates. Pre- and post-transfusion, equilibrated central haematocrits were obtained within 24 h of transfusion in 12 premature neonates undergoing 18 transfusions. Iatrogenic blood loss between pre- and post-transfusion haematocrit determinations was measured for each transfusion event, and infants with detectable, non-iatrogenic blood loss were excluded. Expected haematocrit rise was calculated three different ways using the Behrman, Harriet Lane, and proposed formulas (see text). The Harriet Lane formula predicted haematocrit rise with a correlation, r = 0.66 and slope m = 0.43. The Behrman's formula predicted haematocrit rise with a correlation r = 0.81 and slope m = 0.60. The proposed formula predicted haematocrit rise with a correlation r = 0.79 and slope m = 0.56. On the basis of these findings, we propose the following formula: Quantity PRBC transfused (ml) = 4/3 X desired haematocrit rise X weight (Kg) This formula takes into account the higher blood volume per kilogram body weight seen in premature infants while estimating PRBC unit haematocrit as 0.75 to obviate the need of measurement before each transfusion and, therefore, is an accurate, practical, and simple replacement for the Harriet Lane and Behrman's formulas.     

Changes in transfusion therapy guided by thromboelastograph in cardiac surgery

This study was conducted to determine the use of thromboelastograph in predicting excessive postoperative bleeding, detecting coagulopathy related bleeding, reducing usage of blood and blood products and aiding reexploration decisions. One hundred fifty patients undergoing coronary artery bypass graft surgery under cardiopulmonary bypass were randomized and studied prospectively in two equal groups. In the study group, celite activated heparinase pretreated blood samples, 30 minutes after protamine administration were subjected to thromboelastographic analysis and blood and blood component therapy was administered based on thromboelastograph values, if they had significant bleeding. In the control group transfusion therapy was based on routine coagulation tests and clinical judgement of the surgeon. Patients who bled 100ml / hour in the first three hours or 300 ml in the first three hours and 75 ml/hour in the next three hours were considered significant bleeders. Haematocrit at 0,6,12,18,24,30 and 36 hours of shifting to intensive care unit were noted. Accuracy of thromboelastograph in predicting excess postoperative bleeding was found to be 92%. Consumption of whole blood, packed red blood cells and fresh frozen plasma (p values 0.03, 0.05, 0.001 respectively) was significantly less in the study group. There was poor correlation between postoperative bleeding and platelet count but those who did not bleed had a significantly higher platelet count as compared to those who did. Except at 30 hours, haematocrit was significantly higher in the study group up to 36 hours. Thromboelastograph is a useful diagnostic tool to detect coagulopathies following cardiopulmonary bypass. It helps in instituting appropriate blood and blood component therapy thereby avoiding unnecessary transfusion and associated risks. Accurate detection of coagulopathy is possible with heparinase pretreatment of the blood sample.     

Iron status and the effect of iron supplementation in Thai male blood donors in northern Thailand

The iron status of voluntary and professional male donor groups was investigated. The study indicated that serum ferritin level was lower significantly in those who donated three times per year compared to the first time donors (p less than 0.05) in voluntary donor group. Similar results were observed among the professional donors. Whereas haemoglobin, haematocrit and transferrin saturation were not altered by donating blood in both groups. It also showed that, in general, the body iron stores of professional donors were lower to those of voluntary donors. Supplementation with iron over a period of three months produced a rise in serum ferritin levels and the percentage prevalence of iron depleted subjects decreased from 23.6% to 6.4%. Haemoglobin, haematocrit and transferrin saturation levels also improved.     

The effect of gain in total body water on haemoglobin concentration and body weight following cardiac surgery

BACKGROUND: Haemodilution contributes to a low post-operative haemoglobin concentration in cardiac surgery patients. An assessment of the degree of haemodilution could contribute to the avoidance of red cell transfusion when such an act is based simply on a haemoglobin "transfusion trigger". We have recorded post-operative change in total body water along with body weight to assess the impact of haemodilution on haemoglobin concentration. METHODS: Total body water, measured by bio-electrical impedance analysis, haemoglobin and body weight were measured pre-operatively and on the 1st, 3rd, 5th and 10th post-operative days. The percentage peri-operative change in all three variables was used to examine the paired associations. RESULTS: Total body water and body weight underwent a fall from day 1, with both variables significantly associated up until day 10. Haemoglobin rose steadily from day 1 to 10. This rise was associated with falling total body water and body weight until day 5, but not from day 5 to 10. CONCLUSION: Following cardiac surgery, an individual's fluid state should be considered in determining a patient's need for red cell transfusion. Monitoring body weight provides a simple estimate. Such an approach may reduce the incidence of unnecessary, and potentially counterproductive, transfusion in cardiac surgery patients.     

Incidence of Post-Transfusion Hepatitis before and after Screening for Hepatitis C Virus Antibody

To evaluate the effectiveness of screening test for antibody to hepatitis C virus (anti-HCV), the incidence of acute post-transfusion HCV infection in patients who underwent cardiovascular surgery and received blood transfusion was studied. All patients were followed prospectively with serum biochemistry tests and viral hepatitis markers before and periodically for at least 6 months after cardiovascular surgery. None of them had history of liver disease and none tested positive for anti-HCV prior to blood transfusion. Before blood donors were screened for anti-HCV with a second-generation HCV diagnostic kit, 28 (12.4%) of 226 patients or 0.49% of 5,690 unit transfusion had seroconverted to anti-HCV during a 6-month follow-up. The incidence of post-transfusion hepatitis (PTH) C in 91 patients who had received 1–12 units transfusion was significantly lower than in 135 patients who had received more than 12 units transfusion (6.6 vs. 16.3%, p<0.05). However, none of the 87 transfused patients, since anti-HCV screening in July 1992, developed PTH C (p<0.05). The result demonstrates that screening for anti-HCV by a more sensitive second-generation HCV diagnostic assay may protect the patients studied from PTH C. It further provides a firm argument for the necessity of a nation-wide blood donor screening.     

TT viral infection through blood transfusion: retrospective investigation on patients in a prospective study of post-transfusion hepatitis

AIM To investigate the role of blood transfusion in TT viral infection (TTV).METHODS We retrospectively studied serum samples from 192 transfusion recipients who underwent cardiovascular surgery and blood transfusion between July 1991 and June 1992. All patients had a follow-up every other week for at least 6 months after transfusion. Eighty recipients recipents blood before screening donors for hepatitis C antibody (anti-HCV), and 112 recipients reveiver screened blood.Recipients with alanine aminotransferase level ＞ 2.5 times the upper normal limit were tested for serological markers for viral hepatitis A, B,C, G, Epstein-Barr virus and cytomegalovirus.TTV infection was defined by the positivity for serum TTV DNA using the polymerase chain reaction method. RESULTS Eleven and three patients, who reveiver anti-HCV unscreened and screened blood, respectively, had serum ALT levels ＞90 IU/L. Five patients (HCV and TTV: 1; HCV,HGV, and TTV: 1; TTV: 2; and CMV and TTV: 1 )were positive for TTV DNA, and four of them had sero-conversion of TTV DNA. CONCLUSION TTV can be transmitted via blood transfusion. Two recipients infected by TTV alone may be associated with the hepatitis.However, whether TTV was the causal agent remains unsettled, and further studies are necessary to define the role of TTV infection in chronic hepatitis.     

Pancreatic resections in patients who refuse blood transfusions. The application of a perioperative protocol for a true bloodless surgery

BackgroundThe refusal of blood transfusions compels surgeons to face ethical and clinical issues. A single-institution experience with a dedicated perioperative blood management protocol was reviewed to assess feasibility and short-term outcomes of true bloodless pancreatic surgery.MethodsThe institutional database was reviewed to identify patients who refused transfusion and were scheduled for elective pancreatic surgery from 2010 through 2018. A protocol to optimize the hemoglobin values by administration of drugs stimulating erythropoiesis was systematically used.ResultsPerioperative outcomes of 32 Jehovah’s Witnesses patients were included. Median age was 67 years (range, 31–77). Nineteen (59.4%) patients were treated with preoperative erythropoietin. Twenty-four (75%) patients underwent pylorus-preserving pancreaticoduodenectomy, 4 (12.5%) distal pancreatectomy (DP) with splenectomy, 3 (9.4%) spleen-preserving DP, and 1 (3.1%) total pancreatectomy. Median estimated blood loss and surgical duration were 400 mL (range, 100–1000) and 470 min (range, 290–595), respectively. Median preoperative hemoglobin was 13.9 g/dL (range, 11.7–15.8) while median postoperative nadir hemoglobin was 10.5 g/dL (range, 7.1–14.1). The most common histological diagnosis (n = 15, 46.9%) was pancreatic ductal adenocarcinoma. Clavien-Dindo grade I-II complications occurred in fourteen (43.8%) patients while one (3.1%) patient had a Clavien-Dindo grade IIIa complication wich was an abdominal collection that required percutaneous drainage. Six (18.8%) patients presented biochemical leak or postoperative pancreatic fistula grade B. Median hospital stay was 16 days (range, 8–54) with no patient requiring transfusion or re-operation and no 90-day mortality.ConclusionsA multidisciplinary approach and specific perioperative management allowed performing pancreatic resections in patients who refused transfusion with good short-term outcomes.     

A laboratory evaluation of the Compur M1000 Miniphotometer and the Compur M1100 Minicentrifuge

Summary The Compur Miniphotometer and Minicentrifuge are portable instruments designed for rapid estimation of haemoglobin, red cell count and haematocrit on capillary blood. Haemoglobin and haematocrit results correlate well with reference methods. Accurate red cell counts are only obtained when the sample MCV is within the range 83–103 fl, thus restricting the application of this method. The Compur M1000 Miniphotometer and Compur M1100 Minicentrifuge have been designed as portable instruments to permit rapid estimation of haemoglobin concentration, red cell count and haematocrit by the non-laboratory worker.     

Elective coronary and valve surgery without blood transfusion in patients treated with recombinant human erythropoietin (epoetin-alpha)

BACKGROUND: This study evaluates the real effectiveness of epoetin-alpha associated with ferrous sulphate, in reducing blood transfusion in patients undergoing elective open heart surgery not treated with autologous donation. METHODS: Sixty patients had been divided into 2 groups: group A (30 patients) treated with 525 mg ferrous sulphate three time a day per os for 3 weeks; group B (30 patients) treated with epoetin-alpha 10,000 UI twice a week and 525 mg ferrous sulphate 3 times a day. Grouping of patients has been randomized. In both groups hemoglobin, hematocrit, reticulocytes, iron values, ferritine, transferrine, and serological values, have been evaluated sequentially before treatment, before surgery, day of operation, 1st, 2nd, 3rd, 7th postoperative days and at discharge. RESULTS: In group A 86% patients needed blood transfusion (26 out of 30); in group B only 3% of patients needed blood transfusion (1 patient). One year follow up didn't show side effects related to epoetin-alpha. CONCLUSIONS: This study confirms the real effectiveness of epoetin-alpha in reducing the postoperative need for homologous blood transfusion. No side effects due to epoetin-alpha treatment have been proved. The conclusion is drawn that epoetin-alpha can be used as an alternative to blood transfusion or in association with predeposit and in the treatment of basal anemia.     

A laboratory evaluation of Compur M 1000 Miniphotometer and the Compur M 11OO minicentrifuge

The Compur Miniphotometer and Minicentrifuge are portable instruments designed for rapid estimation of haemoglobin, red cell count and haematocrit on capillary blood. Haemoglobin and haematocrit results correlate well with reference methods. Accurate red cell counts are only obtained when the sample MCV is within the range 83--103 fl, thus restricting the application of this method. The Compur M 1000 Miniphotometer and Compur M 1100 Minicentrifuge have been designed as portable instruments to permit rapid estimations of haemoglobin concentration, red cell count and haematocrit by the non-laboratory worker.     

Predicting transfusions in cardiac surgery: the easier, the better: the Transfusion Risk and Clinical Knowledge score

Background and Objectives  Allogeneic blood products transfusions are associated with an increased morbidity and mortality risk in cardiac surgery. At present, a few transfusion risk scores have been proposed for cardiac surgery patients. The present study is aimed to develop and validate a risk score based on adequate statistical analyses joint with a clinical selection of a limited (five) number of preoperative predictors.
Materials and Methods  The development series was composed of 8989 consecutive adult patients undergone cardiac surgery. Independent predictors of allogeneic blood transfusions were identified. Subsequently, five predictors were extracted as the most clinically relevant based on the judgement of 30 clinicians dealing with transfusions in cardiac surgery. A predictive score was developed and externally validated on a series of 2371 patients operated in another institution. The score was compared to the other existing scores.
Results  The following predictors constituted the Transfusion Risk and Clinical Knowledge score: age > 67 years; weight < 60 kg for females and < 85 kg for males preoperative haematocrit; gender – female; and complex surgery. At the external validation, this score demonstrated an acceptable predictive power (area under the curve 0·71) and a good calibration at the Hosmer–Lemeshow test. When compared to the other three existing risk scores, the Transfusion Risk and Clinical Knowledge score had comparable or better predictive power and calibration.
Conclusion  A simple risk model based on five predictors only has a similar or better accuracy and calibration in predicting the transfusion rate in cardiac surgery than more complex models.     

Predeposit self-transfusion (PDS) in a hepatobiliopancreatic surgery (HBPS) unit: preliminary data

Hepatobiliary pancreatic surgery (HBPS) has high morbility and mortality and frequently requires blood transfusion. Allogeneic transfusion may cause adverse sequelae. Predeposit self-transfusiÓn (PDS) minimizes allogeneic blood transfusion and avoids most adverse reactions. We present the preliminary data of our PDS experience (with recombinant human erythropoieting, r-HuEPO) in HBPS during the first year. We studied our first-year HBPS-PDS program by a retrospective review of the case histories and transfusion records in our Blood Bank. Sex, weight, underlying disease, packed red cell units (PRCUs) requested, drawn, and transfused, and hospital and ICU stays were analyzed. Nine patients were admitted in the PDS program. Of desired blood units, 83% was obtained, successfully in 77.8% of patients, and 63.2% were transfused with autologous blood transfusion. Only three patients needed allogeneic blood (33.3%). All complications occurred in patients who received allogeneic units. Also, we found stays were three times longer in those patients. PDS could be a valid and safe alternative for patients undergoing elective HBPS because it decreases allogeneic blood requirements, reduces overall complications, and also reduces hospital and ICU stays.     

Electrocardiographic changes associated with haematocrit variations.

The electrical resistivity of intracardiac blood is less than the resistivity of the surrounding tissues. This affects the transmission of cardiac forces to the body surface: the radial forces are enhanced, whereas the transmission of tangential forces is diminished (the Brody effect). Blood resistivity is directly related to haematocrit, hence, haematocrit changes are expected to affect the transmission of cardiac forces, resulting in changes in QRS complex voltage. To assess this hypothesis, a 12-lead electrocardiogram was recorded in 40 patients affected by thalassaemia before and after a transfusion of concentrated red cells. The voltage of each QRS component was carefully measured in every lead, and the sum of all R wave amplitudes (sigma R) was calculated. The post-transfusional electrocardiogram reflected a significant decrease in the R wave amplitude in every lead. sigma R also decreased, whereas S wave amplitude in lead V6 increased. A negative correlation between the ratio of haematocrit pre/post transfusion and that of the corresponding sigma R values was also observed (r = -0.434; P less than 0.01). An increase in haematocrit is therefore associated with a decrease in R wave amplitude. These findings explain why several patients with high haematocrit manifest relatively low voltage QRS complexes.     

Intraoperative autologous blood donation and retrograde autologous priming for cardiopulmonary bypass: a safe and effective technique for blood conservation

Haemodilution resulting from crystalloid priming of the cardiopulmonary bypass (CPB) circuit is one of the important reasons for blood transfusion in cardiac surgery, especially in patients with low body surface area (BSA). A prospective study was performed to investigate the technique of intraoperative blood donation (IAD) and retrograde autogous priming (RAP) to limit haemodilution and transfusion requirements. Forty patients with low BSA (<1.7m2) undergoing primary valvular cardiac surgery were assigned to either RAP group or a control group (C). The RAP group (n=20) was subjected to IAD by collecting a calculated volume of blood (272+/-44.3 mL) after induction of anaesthesia. Prior to initiation of CPB the prime volume was reduced by discarding some of it and the CPB reservoir was filled retrogradely through the aortic cannula draining 482+/-78.4 mL of blood. In group C (n=20) only IAD was carried out collecting 295.0+/-62.6 mL of blood. Anaesthetic technique was similar in both groups. Strict transfusion thresholds were observed. There were no significant difference between the groups with respect to baseline characteristics, BSA, type of procedure, perfusion technique and haematologic profile. The haematocrit on CPB was significantly higher in the RAP group as compared with group C (24.2+/-1.3% and 22.1+/-2.5% respectively, p=0.009). Transfusion of allogenic blood during and after surgery was significantly lower in the RAP group (143.6+/-117mL) versus 405.2+/-358.1mL in group C (p=0.02). Postoperative chest tube drainage was 218+/-67.4 mL in the RAP group and 300+/-191 mL in group C which was not significantly different (p=0.18). The technique of intraoperative autologous donation and retrograde priming is simple, safe and cost effective procedure for blood conservation in patients with small BSA undergoing primary valvular surgery.     

Blood Transfusions and Antibody Response in Patients Waiting for a Kidney Transplant1

Abstract: Cold and warm B and T cell antibodies have been investigated following blood transfusion in patients waiting for a kidney transplant. 18 out of 28 patients were sensitized after a single transfusion: half of them presented a B-warm pattern and the other half either a T-warm or a B-cold pattern. Several sera collected after one transfusion were absorbed with pooled platelets. All three T-warm sera have become negative after absorption. Out of 21 B-warm sera, 6 remained B-warm, 3 became B-cold and 12 were negative after absorption. There was no difference in strength between the B-warm sera which were absorbed and those which resisted to absorption. Dilution studies showed that sera followed a similar trend: they convert from T-warm to B-warm and B-cold patterns. Sequential sera from patients receiving systematic transfusions were tested at regular intervals after each transfusion. Most patients produced B-warm antibodies.     

Use of capillary blood count parameters in adults

BACKGROUND AND OBJECTIVES: Capillary samples can provide blood for cell counts in haematologic patients and blood donors. However, some accept only values from venous blood. This study compares capillary and venous blood counts to verify the hypothesis that they are equivalent. MATERIALS AND METHODS: We analysed 463 capillary (fingerstick) and venous blood samples from 428 adults of both sexes (71% haematologic patients, 29% potential blood and apheresis donors). Both samples were taken at the same time from each subject. Haemoglobin (Hb), haematocrit (Hct), white blood cells (WBC), platelets, red blood cells (RBC), mean corpuscular volume (MCV), mean corpuscular Hb (MCH) and mean corpuscular Hb concentration (MCHC) were measured using a haematology analyser (Advia 120, Bayer). RESULTS: Capillary Hb, Hct, WBC, RBC, MCV and MCH were all significantly higher than the venous values [+0.2 mmol/l (+0.3 g/dl), +0.02 l/l (+2%), +0.2 x 10(9)/l, +0.1 x 10(12)/l, +3.1 fl and +0.01 fmol, respectively], whereas the capillary MCHC was lower (-0.6 mmol/l). There was no difference in platelets (-1 x 10(9)/l). Capillary Hb and Hct values were higher in patients with anaemia and polycythaemia, respectively. However, no significant differences occurred in severe thrombocytopenia. CONCLUSION: In adult haematologic patients, however, only the differences in Hb and Hct values may be of clinical relevance. For potential blood and apheresis donors, Hb and platelet screening are equivalent with either capillary and venous blood using a haematology analyser.