[Use of platelet concentrates: a regional experience]. / Utilisation des concentrés plaquettaires : expérience d'une région.

PURPOSE OF THE STUDY: The Établissement français du sang (EFS) distributes two types of platelet concentrates: using a single donor in aphaeresis platelet concentrate (SDAP), versus pooled platelet concentrates (PPC). A retrospective study performed by the Blood Derivatives Group at Observatory for Drugs, Medical Devices and Therapeutic Innovations (OMEDIT), in collaboration with EFS and haemovigilance correspondents from eight regional health care establishments, has analyzed platelet concentrates prescriptions and the position of the prescribers concerning PPC supply. MATERIAL AND METHODS: Between the 2nd and 6th June 2008, 151 platelet concentrates were supplied by ESF. Data were collected for 144 platelet concentrates and in 83 transfused patients with an average age of 50years. During this study, 33 PPC (23%) and 111 SDAP (77%) were supplied. RESULTS: With regards to the 111 SDAP, the supply of PPC was refused in 47 cases (42%), accepted in 18 cases (16%) and unknown for 46 cases (42%). A total of 51 PPC could be supplied during this period, which represented 35% of platelet concentrates prescriptions. The rate of platelets before transfusion was known for 121 platelet concentrates, the median was 32G·L(-1) for SDAP and 44G·L(-1) for PPC. CONCLUSION: More frequent PPC use, with comparable therapeutic efficacy, could be interesting in a context of increasing platelet concentrates consumption in health care establishments. Moreover, prescribers did not seem to be against the idea. An information pamphlet on platelet concentrates was drafted and distributed to prescribers in order to promote the prescription of PPC. A second assessment is planned to measure the impact of this communication.

[Suitability of red blood cell transfusion: a multicenter study]. / Évaluation multicentrique de la pertinence des prescriptions de concentrés de globules rouges.

The purpose of this retrospective observational multicenter study was to assess appropriateness of red blood cell (RBC) transfusion, according to the French national guidelines (Agence française de sécurité sanitaire des produits de santé) published in 2002. Six hundred and thirty-nine RBC transfusions from nine institutions have been randomly selected and analysed. The data collected are issued from different specialities. Patients' characteristics, occurrences of transfusion, admission, pre-transfusion, post-transfusion and discharge haemoglobin concentrations have been collected. Two physicians (who are in charge) must evaluate the appropriateness of pre-transfusion, discharged haemoglobin concentrations, quantity and quality of transfused RBC. The mean pre-transfusion haemoglobin concentration was 7.89 ± 1.24, the median number of transfused RBC was two (extremes: 1-16), the mean discharge haemoglobin concentration was 10.14 ± 1.30 (-5 days after the end of transfusion). The pre-transfusion and discharge haemoglobin concentrations were higher if the patient presented a co-morbidity factor. Ninety-three percent of pre-transfusion and 79% of discharge haemoglobin concentrations are in accordance with the guidelines. According to the physicians, the RBC transfusions are too "precocious" when pre-transfusion haemoglobin concentration is above nine and the anaemia is asymptomatic. 50% of RBC transfusion with discharge haemoglobin concentration above 10 is not excessive. In case of acute anaemia, the pre-transfusion and discharge haemoglobin concentrations are higher and RBC transfusion excessive. In this study, the trigger haemoglobin concentration is "restrictive", but the target haemoglobin concentration is "liberal" with a high-discharge haemoglobin concentration. Inappropriate RBC transfusions are mainly due to over-transfusion.

[Assessment of knowledge in blood transfusion of medical staff in 14 state-run hospitals]. / Evaluation des connaissances médicales transfusionnelles dans 14 établissements publics de santé

UNLABELLED: This multi-centre study aimed to assess the knowledge in blood transfusion of medical staff in 14 state-run hospitals. MATERIALS AND METHODS: A questionnaire was distributed to all potential prescribers of blood products. It contained 35 questions concerning various subjects: blood products, immuno-haematology, prescription of blood products, transfusion practice, interpretation of the final bedside controls. The rate of correct answers (RCA) was obtained for each question, for each subject, and for nine questions defined as essential for patient safety. A weighted score was also calculated by ranking each question between one and six according to its importance. RESULTS: Six hundred and ninety four questionnaires were analysed (rate of return 15%). The RCA ranged from 14 to 89%, according to the questions. The RCA ranged from 47 to 78% for seven of the nine essential safety questions, and 82% and 83% for the two questions concerning the interpretation of incompatible final bedside controls: there were 9% of wrong answers, which validated an incompatible blood transfusion. The mean weighted score was 62%. Both the RCA and the weighted score were higher for those that regularly prescribe blood products than for that only prescribe them occasionally. There were no significant differences between hospitals. CONCLUSION: This study has confirmed that medical staff have deficiencies in their knowledge of blood transfusion, deficiencies which are acknowledged by medical staff. These first results will help the members of the study group to develop and prioritize various actions to improve this state of affairs, and to follow the effects of the training given.

Prolongation of discordant heart xenograft survival after liver hemoperfusion: role of nonparenchymal liver cells.

In the discordant guinea pig (GP)-to-rat combination, heart xenografts are hyperacutely rejected. The aim of the present study was to demonstrate that a donor-species-specific extracorporeal liver hemoperfusion can prolong survival of discordant heart xenografts and to specify the role of non-parenchymal cells. GP hearts were grafted into Brown Norway rats (group 1) In group 2, heart xenografting was carried out immediately after a 15-min GP hemoperfusion. In group 3, Kupffer cells of the GP liver were blockaged by intravenous injection of dextran sulfate (4 mg/100 g) 30 min before hemoperfusion. In group 4, Kupffer cells of the liver were activated by intravenous injection of muramyl dipeptide (MDP; 500 micrograms/250 g) 24 h before hemoperfusion. Lymphocytotoxic antibodies were detected according to a complement-dependent antibody assay. A donor-specific liver hemoperfusion can delay hyperacute rejection of heart xenografts (67.6 +/- 47.1 min in group 2 versus 8.0 +/- 2.4 min in group 1; p < 0.01) and reduce the level of lymphocytotoxic antibodies. Deposits of immunoglobulins and complement were significant on the hemoperfused liver and moderate on the transplanted heart. In group 3, after blockade of Kupffer cells with dextran, heart xenograft survival was less prolonged (31.8 +/- 8.2 min) and the decrease in antibody levels was not significant and associated with moderate deposits of immunoglobulins and complement on the hemoperfused liver and significant deposits on heart xenografts. In group 4, after stimulation of Kupffer cells by MDP, a significant decrease in antibody levels was present, and significant deposits were observed. These results show that donor-specific liver hemoperfusion can prolong the survival of discordant heart xenografts and support the hypothesis that nonparenchymal liver cells play a major role by absorption of preformed antibodies and complement.

Role of nonparenchymal liver cells in guinea pig to rat hepatic xenotransplantation.

This work was undertaken to investigate the role of nonparenchymal liver cells in a discordant model of hepatic xenografting. Three experimental groups were established: in group 1 guinea pig to Lew rat liver xenotransplantations were performed; in group 2 both donor and recipient were treated with dextran sulfate, a known inhibitor of the reticuloendothelial system phagocytic function; in group 3 both donor and recipient were injected with muramyl dipeptide, a synthetic immunomodulator stimulating the monocyte/macrophage axis. Survival time was assessed and xenoantibody titers 30 min before and after the intervention, Kupffer cell activity 30 min after transplantation, histology and immunoglobulin and complement deposits of the grafted liver were evaluated too. Survival time of the xenografted rats in group 1 was 6.4 +/- 0.31 h. Blockade of Kupffer cells by dextran sulfate administration significantly (p < 0.001) depressed the survival time (2.9 +/- 0.31 h) of the grafted rats, while a significant increase (p < 0.001) was observed in the muramyl dipeptide-treated group (9.3 +/- 0.52 h). A significant reduction of xenoantibody titers 30 min after intervention was observed in the muramyl dipeptide group while no reduction was observed in the dextran group. Thirty minutes after xenotransplantation sheep red blood cell 51Cr uptake was significantly depressed by dextran sulfate treatment while muramyl dipeptide administration restored the Kupffer cell activity. Histological changes worsened after dextran administration in comparison with the other groups. Immunoglobulins and complement deposits were diminished by dextran administration.(ABSTRACT TRUNCATED AT 250 WORDS)