Adverse transfusion reactions with neurological signs in transfused patients.

Objectives: Many transfused patients present severe, sometimes critical, clinical conditions. The occurrence of adverse transfusion reactions may cause the clinical condition to deteriorate. A study was conducted aimed at establishing whether the presence of neurological signs during an adverse transfusion reaction increases its severity.

Methods: From 1 January 2010 to 30 June 2019, adverse reactions with neurological signs were extracted from the French haemovigilance database system. Two signs observed at the time of the reaction were analysed: unconsciousness and convulsions. Stroke was excluded. The type of reaction, its severity, the blood product involved and its imputability were all studied.

Results: During the study period, 10,670 reactions were reported, including 20 (0.19%) imputed to the transfusion with unconsciousness and/or convulsions. Unconsciousness without convulsions was frequently observed (14 reports, 70.0%). Convulsions were reported in 5 cases (25.0%), with 1 case being associated with unconsciousness. Unconsciousness and/or convulsions were present in 9 allergic reactions (45.0%) and 4 transfusion-associated circulatory overloads (20.0%). Nine reactions were severe (45.0%), 7 were life-threatening (35.0%) and 1 case resulted in the recipient's death (5.0%). A red blood cell and a platelet concentrate transfusion were involved in 8 reactions (40.0%) each, although the imputability of the blood product was certain in only 2 of the reactions.

Conclusion: Unconsciousness and/or convulsions were rarely observed in adverse reactions reported in transfused patients. Nevertheless, the presence of these signs highlights the severity of the adverse reactions (17 reactions, 85.0%).