Unacknowledged adverse transfusion reactions: Are they a mine to dig?

Haemovigilance has long tried to characterize and understand transfusion reactions in order to prevent them. Unacknowledged ones are now a minority but they question us. Are they the result of incomplete clinical setting and/or insufficient medical reasoning, or can they contain real new entities we have not yet understood?

Ten volunteer experts reviewed 30 recent unacknowledged cases. Their diagnostic propositions were compared with data issued from a five-year repository we have analysed in terms of statistical links between clinical signs and diagnoses.

Experts' opinions are only quite unanimous in 60% of the cases, and the proposed diagnosis remains unacknowledged in 53%. Repository comparison shows that signs like pain or digestive symptoms are far more frequent in unknown reactions. However, it is more the absence of some other signs which drives to that conclusion, in a default diagnosis mechanism.

Errors in transfusion reactions medical analysis are rare. Unacknowledged cases are more often linked to poor or unspecific clinical setting. But a particular attention must be paid with infrequent diagnoses which are far less characterised, like metabolic complications. Pain high occurrence in unknown cases also commands us to go further in the characterisation of acute pain transfusion reaction diagnosis, which is suggested by some authors.