A 23 years audit of packed red blood cell consumption in a university hospital in a developing country.

BACKGROUND: There is paucity of information on the blood transfusion practice in developing countries. The current audit aims to find out the long term trend in the consumption of packed red blood cells (PRBCs) in a large Saudi teaching hospital in Riyadh MATERIALS AND METHODS: We analyzed the annual consumption of PRBCs from 1985 to 2007 in seven major hospital divisions (Medicine, General Surgery, Pediatrics, Obstetrics and Gynecology, Cardiac Surgery, Accident and Emergency and Renal Dialysis Unit) at the 850-bed King Khalid University Hospital (KKUH), Riyadh. RESULTS: Grand total consumption of PRBCs was 345,642 units. The consumption increased gradually and peaked in the year 1994, dropped to 30.4% 6 years later and then increased gradually thereafter, due to the expansion in the number of patients cared for in the Departments of Medicine, Cardiac Surgery and Accident and Emergency, while in the Department of Pediatrics the drop in consumption continued unabated. In the Renal Dialysis Unit consumption was minimal with the use of erythropoietin therapy. The crossmatch:transfusion ratio uncovered gross over-ordering of PRBCs and wastage of blood bank resources in most hospital divisions most notably in the Department of Obstetrics and Gynecology. CONCLUSION: The results obtained indicate clearly that there has been overuse of blood products that dropped markedly in years coinciding with the worldwide apprehension about the safety of transfusion therapy particularly HIV transmission. This factor in addition to the current implementation of strict guidelines is gradually improving transfusion practices in our institute.

The prevalence of lupus anticoagulant in normal pregnancy and in women with recurrent fetal loss--recommendations for laboratory testing for lupus anticoagulant.

BACKGROUND: There is wide disagreement in the literature on the rate of detection of lupus anticoagulant (LA) in women with recurrent fetal loss (RFL). The aim of this study was to determine the prevalence of LA using four phospholipid-dependant coagulation tests in a large population of Saudi women. PATIENTS AND METHODS: We determined the prevalence of LA in women with RFL (n=925), normal pregnancy (n=663), and in healthy blood donors (n=204), at the King Khalid University Hospital, Riyadh. The following coagulation tests were employed: the activated partial thromboplastin time (APTT), platelet neutralization procedure (PNP), kaolin clotting time (KCT) and the dilute Russel's viper venom test (dRVVT). RESULTS: In RFL patients, positive APTT was 10.2%, APTT+PNP 3.6%, KCT 10.5%, and dRVVT 10.9%. In normal pregnancy, the corresponding figures were 12.8%, 3.1%, 10.8%, and 5.6%. Three positive tests occurred in 2.3% of RFL patients, including APTT+KCT 3.5%, APTT+dRVVT 3.9%, and KCT+dRWT 4.1%. The corresponding figures for normal pregnancy were 1.6% for three positive tests, and 3.0%, 1.8%, 2.4%, respectively. The dRVVT was the only test that showed a rate of positive results almost double that seen in normal pregnancy. CONCLUSIONS: If only one or even two screening tests were performed, a significant number of LA positive cases would have been missed. This could make a difference to treating physicians as to the possible etiology and management of RFL. It is therefore advisable to routinely use the three tests (APTT, KCT and dRRVT) when screening for LA.

Clotting factor VIII (FVIII) and thrombin generation in camel plasma: A comparative study with humans.

The objective of this study was to characterize the highly elevated levels of clotting factor VIII (FVIII) in camel plasma. Whole blood was collected from healthy camels and factor VIII clotting activity (FVIII:C) assays were conducted using both the clotting and the chromogenic techniques. The anticoagulant citrate phosphate dextrose adenine (CPDA) produced the highest harvest of FVIII:C, the level of plasma factor VIII, compared to heparin:saline and heparin:CPDA anticoagulants. Camel FVIII can be concentrated 2 to 3 times in cryoprecipitate. There was a significant loss of camel FVIII when comparing levels of FVIII in camel plasma after 1 h of incubation at 37°C (533%), 40°C (364%), and 50°C (223%). Thrombin generation of camel plasma is comparable to that of human plasma. It was concluded that camel plasma contains very elevated levels of FVIII:C, approaching 8 times the levels in human plasma, and that these elevated levels could not be attributed to excessive thrombin generation. Unlike human FVIII:C, camel FVIII:C is remarkably heat stable. Taken together, these unique features of camel FVIII could be part of the physiological adaptation of hemostasis of the Arabian camel in order to survive in the hot desert environment.

L'objectif de la présente étude était de caractériser les niveaux très élevés du facteur de coagulation VIII (FVIII) dans le plasma de chameau. Du sang entier a été prélevé de chameaux en santé et des épreuves d'activité de coagulation du facteur VIII (FVIII:C) ont été effectuées en utilisant des techniques chromogéniques et de coagulation. L'anticoagulant citrate phosphate dextrose adénine (CPDA) a permis la récolte la plus élevée de FVIII:C, le niveau plasmatique de facteur VIII, comparativement aux anticoagulants héparine:saline et héparine CPDA. Le FVIII de chameau peut être concentré 2 à 3 fois dans des cryoprécipités. Il y avait une perte significative de FVIII de chameau lorsque l'on comparait les niveaux de FVIII dans le plasma de chameau après 1 h d'incubation à 37 °C (533 %), 40 °C (364 %), et 50 °C (223 %). La génération de thrombine dans le plasma de chameau est comparable à celle dans le plasma humain. Il a été conclu que le plasma de chameau contient des niveaux très élevés de FVIII:C, atteignant près de 8 fois le niveau dans le plasma humain, et que ces niveaux élevés ne pouvaient pas être attribué à une génération excessive de thrombine. Comparativement au FVIII:C humain, le FVIII:C de chameau est très stable à la chaleur. Prises dans leur ensemble, ces caractéristiques uniques du FVIII de chameau pourraient faire partie de l'adaptation physiologique de l'hémostase du chameau arabe afin de lui permettre de survivre dans l'environnement chaud du désert.(Traduit par Docteur Serge Messier).