[Immuno-hemolytic transfusion reactions. IV. Analysis, risks and prevention]

Red blood cell alloantibodies in paediatric transfusion in sub-Saharan Africa: A new cohort and literature review

Blood transfusion support predisposes transfused children to the risk of erythrocyte alloimmunization in Sub-Saharan Africa. A cohort of 100 children receiving one to five blood transfusions were recruited for screening and identification of irregular antibodies using gel filtration technique. The mean age was 8 years and the sex-ratio at 1.2. The retrieved pathologies were: major sickle cell anaemia (46%), severe malaria (20%), haemolytic anaemia (4%), severe acute malnutrition (6%), acute gastroenteritis (5%), chronic infectious syndrome (12%) and congenital heart disease (7%). The children presented with haemoglobin levels ≤6 g/dl, and 16% of them presented positive irregular antibodies directed against the Rhesus (30.76%) and Kell (69.24%) blood group systems. A literature review shows that irregular antibody screenings vary from 17% to 30% of transfused paediatric patients in Sub-Saharan Africa. These alloantibodies are in particular directed against the Rhesus, Kell, Duffy, Kidd and MNS blood group and generally found in sickle cell disease and malaria. This study highlights the urgent need of extended red blood cell phenotyping including typing for C/c, E/e, K/k, and Fya/Fyb, and if possible Jka/Jkb, M/N, and S/s for children before transfusion in Sub-Saharan Africa.

Blood groups, hemoglobin phenotypes and clinical disorders of consanguineous Yansi population

AIM: To study frequency of blood groups, prevalence of sickle-cell anemia trait and glucose-6-phosphate dehydrogenase deficiency (G6PD), among consanguineous Yansi tribe.

METHODS: A total of 525 blood samples were collected, of which 256 among the Yansi population, and 269 for the unrelated control group in the Bandundu province of Democratic Republic of Congo. Blood group antigens were determined in the following systems: ABO, Rh, Kell, Duffy, Kidd and MNS. Blood grouping and extended phenotype tests were performed according to standard immunohematological procedures. Spot tests and tandem mass spectrometry were used respectively for the assessment of G6PD and sickle-cell anemia trait.

RESULTS: The frequency of ABO phenotypes conformed to the following order O>A>B>AB with notably 62.5%, 23.8%, 12.1% and 1.6% for the Yansi, and 54.6%, 27.5%, 14.1% and 3.7% for the unrelated control group, respectively (P = 0.19). As for the Rh phenotypes, the most frequent were ccD.ee, ccD.Ee, CcD.ee, corresponding to 71.5%, 12.1% and 12.1% for the Yansi, and 70.6%, 15.6% and 8.2%, for the unrelated control group (P = 0.27). The frequency of MN and Ss phenotypes were statistically different between groups (P = 0.0021 and P = 0.0006). G6PD was observed in 11.3% of subjects in the Yansi group, and in 12.4% of controls (P = 0.74). The sickle-cell anemia trait was present in 22.4% of Yansi subjects and 17.8% in the control group (P = 0.24). Miscarriages and deaths in young age were more common among Yansi people.

CONCLUSION: This study shows a significant difference in MNS blood group distribution between the Yansi tribe and a control population. The distribution of other blood groups and the prevalence of hemoglobinopathies did not differ in the Yansi tribe.

Connaissances et pratiques du personnel soignant en matière de sécurité transfusionnelle

Blood transfusion is a complex activity, involving many actors. It is a high risk activity which couldn't be controlled without the use of specific methods. Health care workers beliefs and organisational factors are two major issues for the blood transfusion safety. Our study objectives were to describe the paramedical staff's knowledge and practice regarding blood transfusion safety and to identify factors that are related to them. We carried out a cross sectional study. The information was gathered by using a questionnaire. The latter was developed by foreign teams and adapted to the local context. Two outcome measures were used: the knowledge and practice score and the proportion of true answers. The study showed that only 15% of the interviewed persons have had a score less than 30 (scale range from 0 to 100), i.e. only 15% have had appropriate knowledge and practice with no negative consequences for the patient safety. 13.8% of the study population provided right answers related to the biologic exams required before red cells transfusion and 34% for the abnormal reaction circumstances. These results underscores the importance of strategies improving the quality and the safety of blood transfusion, i.e. the continuous medical education, implementing a blood transfusion information system and the use of transfusion practice guidelines.

Évolution des risques transfusionnels en 15 ans (1987–2002)

The majority of countries considered the consequences of post-transfusion infections to refer to HIV. However, the organisations and transfusion systems have been revised. The author's objective is now to measure the efficiency of these decisions with regards to risk prevention. The first step was to first draw up a list of these risks so as to obtain a definition which would be accepted throughout Europe. Having looked at the major tendencies between 1993 and 2002, the author made predictions for the following ten years. The ratios benefit-risk and cost-efficiency were also looked at.

La responsabilité du médecin prescripteur de produits sanguins labiles

Blood transfusion presents mainly virological, bacteriological, immunohaematological and volemic risks; with the latter two particularly concerning health establishment employees. This article tackles the physician's responsibility in blood transfusion. Taking into account the regulations that surround the activity, prescribing physicians must know and put into action the relative requirements in their practises in order to avoid taking on its responsibility, or that of the health establishment in which they work, as any lack of respect for the rules and regulations could result in being held liable for any side affects suffered by the patient. The article has the objective of identifying the main regulation requirements in order to control them despite a difficult environment, from the point of view of patients' rights regarding the benefits and the consequences of transfusion. These requirements focus mainly on information and patient consent, the prescription of blood products as well post transfusion information and the follow-up care. Proof of respect for these rule requirements must be available for each of these aspects.

The release of unsuitable units through misinterpretation of laboratory results transmitted by facsimile

BACKGROUND

Preventable errors in transfusion medicine that have a significant risk of adverse outcome include the erroneous administration of blood of the wrong type or blood with unsuitable laboratory test results. Mandatory reports of errors by facilities providing blood services in New York State offer the opportunity for review and analysis of common factors. The state also collects statistics on the collection, laboratory testing, distribution, and disposition of blood in these facilities.

CASE REPORTS

Three serious errors in transfusion medicine occurred within 3 months as a result of the misinterpretation of laboratory test results transmitted by facsimile. Two unsuitable units of blood were erroneously released, and a unit mislabeled as to the ABO group was incorporated into the hospital inventory. One of the unsuitable units was repeatedly reactive for HIV (although negative on confirmatory testing), and the other was confirmed positive for HCV.

CONCLUSIONS

The vast majority of blood collected in New York State is tested by reference laboratories. Results are often transmitted by facsimile. Facsimile results may be misinterpreted because of distortion during transmission, misreading, or failure to note a separate report of pending results. Such misinterpretation results in an increased risk of adverse outcome for transfusion recipients. Laboratory results to be transmitted by facsimile could readily-and should-be clarified.

[Immunologic risk analysis of blood transfusion: 1991-1998]

The immunologic risk associated to erythrocyte transfusions is bound to the polymorphism of blood group systems and to the respect of blood transfusion regulations. The results of three studies are presented, which were carried out respectively by the French Society of Blood Transfusion, the National Institute of Blood Transfusion and the National Haemovigilance Network. Two hundred and twenty-seven cases of immunologic accidents are analysed using the Kaplan's interpretation model and the traditional method of process analysis. The results show three critical factors in the occurrence of this type of incident: the relevance of the clinical examinations prescribed, the way in which the biological results are taken into account, and the relationship/exchange of information between private and public hospitals, and blood transfusion centers.

[Final bedside verification: results of a national survey of reagents and devices used in France]

The national reference Center for blood groups checked samples of reagents and devices used in France for a definitive verification of pretransfusion ABO tests performed at the patient's bedside, as defined by French health authority regulations. The results of an initial inquiry was published in 1991. The new study shows no significant improvement of the quality of reagents and devices. This is a major concern considering the importance of ABO incompatibility in severe hemolytic transfusion reactions.

Reliability of the pretransfusion bedside compatibility test: association with transfusion practice and training

BACKGROUND

The utility of a pretransfusion bedside blood compatibility protocol to decrease immunohemolytic accidents has been questioned for years.

STUDY DESIGN AND METHODS

The reliability of a standard bedside ABO compatibility test was evaluated with a stratified random sample of 48 nurses who performed agglutination testing by using Bristol cards, interpreted compatibility, and decided whether to transfuse red cells for 12 randomly and blindly selected donor-and-recipient blood sample pairs. An expert judged technical performance and the interpretation of each card.

RESULTS

Erroneous decisions occurred in 18.2 percent of 576 tests, including 12 decisions to transfuse incompatible blood. Errors involved both testing protocols and the interpretation of compatibility. Anti-A and anti-B were detected with 92.8-percent sensitivity and 95.9-percent specificity. The expert judged 17.7 percent of tests to be technically inadequate, most often because of the application of excess blood to the card and a lack of rotation of the card. Testing errors (16.1% of tests) were significantly linked to infrequent transfusion activity by the nursing service, inexperience, and insufficient training. Compatibility misinterpretation occurred in 14.6 percent of the tests and was significantly linked to the nurses' infrequent transfusion activity, inexperience, insufficient training, lack of practical experience, and confusion regarding the use of ABO-compatible but not identical blood.

CONCLUSION

Bedside pretransfusion compatibility determination should not be considered a reliable supplemental safety procedure in the hands of inexperienced and insufficiently trained operators.

[Benefits and risks of scheduled autologous transfusion]

Blood transfusion, like any other medical activity, requires an analysis of the risk/benefit ratio for each patient. Autologous blood transfusion does not escape this golden rule. The benefits expected of scheduled autologous transfusion consist of the reduction of the risks inherent in homologous transfusion. Those benefits are indisputable in erythrocyte alloimmunisation and viral or parasitic disease transmission. But the risks attached to such protocols have often been underestimated. The risks for the patient are still linked to the transfusion of autologous labile blood products (haemolysis, bacterial infections) or to consequences of whole blood donations (cardiovascular intolerance, increased use of transfusion, increased operative bleeding). There are also risks for the patient community insofar as autologous blood products which do not all meet the same criteria of clinical and biological validation as homologous blood products are circulated in care institutions.

[Contribution of hemovigilance to immunologic safety of blood transfusions: assessment after 3 years]

The haemovigilance system has indirectly introduced three types of information: a more precise tally of accidents and risks (even if the total number of events remains difficult to assess); an evolution of the mode of collecting relevant information (even if, after 3 years, it has become important to define new objectives and collection procedures); the identification of the main causes of errors leading to immunological accidents allowing the elaboration of schemes pointing out the possible failures and critical points of the various processes, such as blood bag distribution, ABO control at bedside, the prescription of examinations prior to transfusion. The analysis of haemovigilance data has induced a number of important consequences, particularly clinical practitioners' awareness of blood transfusion risks; elaboration of reliable and documented tools for the training of professionals and the information of patients; implementation of corrective and preventive measures, particularly to reduce accidents due to ABO incompatibility. These haemovigilance data will provide more fruitful results when cross-analysed with data from the reactovigilance system which is being set up. Until then, they will largely be used to elaborate blood transfusion quality assurance standards.

[Improvement of transfusion safety in a health care service through the implementation of a quality program]

The quality policy brings with it an efficient method as well as relevant tools to improve transfusion safety in health care services. This article illustrates the details of the approach through the presentation of a project developed in the East Picardie region throughout several hospitals. It underlines the importance of the choice of a good reference system, of a pertinent method and the necessity of a real project management. Furthermore, the follow-up of the project has enabled us to identify a certain number of success criteria in the steering of the changing process.