Hypotensive transfusion reactions in the era of prestorage leukoreduction.
BACKGROUND
Clinical characteristics of hypotensive transfusion reactions (HyTRs) have not been evaluated in the context of universal prestorage leukoreduction.


STUDY DESIGN AND METHODS
A retrospective review of medical records of patients with HyTRs during the years 2011 and 2012 was performed at two academic medical institutions.


RESULTS
Thirty-five patients with 35 HyTRs were identified, with an incidence of 1.33 per 10,000 transfusions. Red blood cells (RBCs) were implicated in 21 (60.0%) reactions and platelets (PLTs) and plasma (PL) in 11 (31.4%) and three (8.6%), respectively. The HyTR rate per blood component was 0.019% for PLTs, 0.015% for RBCs, and 0.006% for PL. Mean patient age was 65 years (range, 2 months-87 years), five (14.3%) were pediatric (<18 years), and 20 (57.1%) were male. The most frequent clinical settings associated with HyTRs were cardiac surgery (n=13; 37.1%), hematology-oncology diseases (n=11; 31.4%), and general surgery (n=7; 20.0%). Extracorporeal circuits were used within 24 hours before the reaction in 16 patients (45.7%), including nine patients on cardiopulmonary bypass, four on dialysis or continuous venous-venous hemodialysis, and three on extracorporeal membrane oxygenation. Four patients (11.4%) received an angiotensin-converting enzyme inhibitor within 24 hours before the HyTR. Seventeen patients (48.6%) responded to stopping the transfusion and supportive treatment. Thirteen patients (37.1%) had severe reactions. No HyTR resulted in death.


CONCLUSION
In the absence of bedside leukoreduction filters, several medical situations are associated with HyTRs. The pathophysiology of HyTRs is yet to be defined. The US hemovigilance system allows for standardization of transfusion reactions, which facilitates their classification and study.