[Quality assurance and prevention of immuno-hemolytic incidents in blood transfusion]

Démarche qualité en hémovigilance : analyse du processus transfusionnel

Blood transfusion, like any effective therapy, involves an element of risk. In order to reduce such risks to a maximum, a legislative and statutory framework has been set up. A reliable evaluation of this system is necessary together with an efficient evaluation method whose aim is to guarantee quality service. Favouring the development of the evaluation of professional practices is one of the priorities of the National Agency of Accreditation and Evaluation in Health (ANAES) created in April 1996. Following the recommendations from ANAES, the University Hospital of Brest decided to set up an evaluation of blood transfusion chain from the prescription of blood products to the transfusion act and follow-up of receivers in two health care services. The method used for this evaluation was a clinical audit. It is a method of evaluation, which allows with the help of certain criteria, care practices to be compared to accepted references, in order to measure the quality of these practices and the results of hospital care, so that improvements may be added. We present here the method and results of this evaluation, as well as the improvements we have put in place.

[Evaluation of the immediate transfusion reaction incident reporting system at the Brest University Hospital Center]

The Haemovigilance Unit of Brest University Hospital has had a reporting system of transfusion reactions since october 1994. Reporting "any unexpected or undesirable effect due or likely to be due to the administering of blood cell components" must be done on an answering machine immediately or in the next eight hours. The main goal of the evaluation of this epidemiological surveillance system was to assess its sensitivity, its positive predictive value, its acceptability, its timeliness and its simplicity, according to the Centers for Disease Control criteria. An exhaustive monitoring of the immediate transfusion reactions (ITR) occurring within the 24 hours following the procedure was conducted from April 1, to June 30, 1998. Two sources of information were used, the spontaneous notification to the Haemovigilance Unit using the answering machine, and a telephone survey of the nurse responsible for the transfusion or post-transfusion follow-up. During the survey, 19 ITR, among which 12 were reported to the Haemovigilance Unit on the answering machine, were recorded. The incidence rate of the I.T.R. was estimated at 5@1000 transfused blood cell components. The sensitivity of the notification system was estimated at 63% (95% confidence interval: 41-85) and the positive predictive value at 70% (95% confidence interval: 48-92). This notification system is operational. The function of sanitary alert is ensured at the primary level of the system surveillance. The undernotification of the ITR (37% of false negative) must be corrected by specific recommendations.

[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.

A sequential procedure to test the progressive decrease of rare adverse events

A program to construct the Rapid Sequential Test (R-ST), a sequential procedure to test the decrease of the rate of rare adverse events, is described. This sequential procedure is constructed with the Sequential Probability Ratio method. It relies on a model for the progressive decrease in the rate of adverse events from a given initial rate to a target rate, during a transition period. The program allows one to calculate the bounds of rejection of the R-ST, and to study its power under various types of decrease. It is shown that the R-ST gives a conclusion faster than standard sequential procedures for the same type I and II error, saving at least one quarter of the trials completed during the transition period. The use of the software to construct R-STs is discussed with respect to the specification of the model.

[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.