The risk of transfusion to the wrong patient in Germany

As blood components become increasingly safer through improved donor selection and infectious disease testing, efforts to improve safety focus on the process of blood transfusion. This process includes determining the appropriateness of transfusion, matching blood components and patients, and monitoring recipients for possible adverse reactions. Important iatrogenic risks of the process are an overly liberal transfusion strategy1 and transfusions to patients for whom they were not intended. Estimates for the risk of transfusing blood to the wrong patient vary between 1 in 400 (Belgium),2 to 1 in 19,000 (United States),3 to 1 in 27,007 (Scotland). 4 However, these estimates were obtained by different methods. In Germany, ABO testing of the patient’s blood at the bedside immediately before transfusion is performed to prevent ABO transfusion errors. In a retrospective study, we sent a questionnaire to 79 German blood transfusion services and asked for the number of reported transfusion errors, as well as the total number of transfused RBC concentrates, and other components. For every reported transfusion error, we asked for the patient’s age and gender, medical speciality, date of error, type of blood component, clinical consequences, information concerning the person responsible for the transfusion, and information concerning bedside ABO testing results. Twenty-nine institutions responded and 24 data sets could be analyzed. Of these, 15 responses were from university hospital blood banks, 5 from large hospitals, 2 from small hospitals, and 2 were from German Red Cross blood transfusion services. Thirty-six transfusion errors were reported for RBC concentrates. There was no denominator (total units transfused) for 8 of the transfusion errors. Thus, the estimated risk is 28 in 1 million or 1 in 36 000 with respect to reported errors. Thirty-two patients were involved. Twenty-nine patients received one erroneous RBC unit; 2 received 2 erroneous units; and 1 received 3 erroneous units. Two of the 32 patients died as a result of the transfusion error; one survived with permanent impairment; 8 were referred for intensive care treatment. No medical consequences were reported for 19 patients (Table 1). Of these 19 patients, however, at least one-third were in an intensive care unit when the transfusion was administered. In an additional one-third, the transfusion error was not ABO related. At least two patients who received erroneous transfusions and who had “no consequences” were reported to have died after the transfusion from their underlying diseases. For 2 patients, no follow-up was reported. In theory, a proficient and fully implemented program of ABO bedside testing should prevent most ABO errors. However, our study revealed that no bedside ABO testing was performed for 4 of the 32 patients. For 16 patients, the transfusion error occurred after the bedside ABO test, which reflects an interruption between the bedside test and transfusion. For 2 patients, the interpretation of the bedside ABO test was erroneous. For 5 patients tested at the bedside, the error was reported to be unrelated to ABO matching. This included two D+ units transfused to D– patients. Two additional patients had bedside ABO testing but the nature of the error was not well defined. No information was reported on the bedside test for 3 patients (Table 2). Of the four transfusions without bedside testing, one was administered by a medical student (and resulted in death of the patient), and another by a guest (nonstaff) physician. The third case was by a resident, and the fourth by a consultant. The transfusion errors occurred in anesthesia (9), surgery (6), thoracic surgery (3), gynecology (2), urology (1), internal medicine (6), hematology (2), nephrology (1), pediatrics (1), and unknown (1). Retrospective reporting of transfusion error events is likely to underestimate the incidence because some errors may not be recognized and even recognized errors may not always be reported.3 A prospective study on TABLE 1. Consequences of transfusion errors in 32 patients Consequence Number Death 2 Permanent impairment 1 Intensive care treatment 8 No consequence* 19 No information 2 Total 32