The Incidence of Transfusion-Related Acute Lung Injury at a Large, Urban Tertiary Medical Center: A Decade's Experience.

Background: While transfusion-related acute lung injury (TRALI) remains the primary cause of transfusion-related fatalities (37%), recent reports estimate the incidence of TRALI at 0.008% per unit of plasma transfused and 0.004% per all products transfused. Because blood banks have moved toward male-predominant plasma, TRALI appears, anecdotally, to have been reduced to an extremely rare event. The purpose of this study was to estimate the current incidence of TRALI at a large, urban center known for its early and aggressive use of plasma in the setting of trauma, hemorrhagic shock, and massive transfusion.

Methods: The Blood Bank Registry of our hospital was queried for all transfused patients admitted from September 2002 through March 2013. The blood bank collected and investigated all cases of clinical acute lung injury meeting the consensus definition for TRALI, as well as potential cases for which the donor product was recalled for having a high reactivity level of human leukocyte antigen antibodies (ie, the antibodies that could cause TRALI). Clinical reactions were reviewed in conjunction with independent serological testing and classified by transfusion medicine physicians as being "probable TRALI" or of "unrelated etiology." The total number of units transfused at our facility during this time period was also obtained, allowing the incidence of TRALI to be estimated. Cases were analyzed based on demographics, outcome, blood types, observed symptoms and their duration, and type of product transfused.

Results: Seven cases were identified at our center for the indicated time period, with only 3 of these occurring in trauma. A total of 714,757 units of blood products were transfused between September 2002 and March 2013. The incidence of TRALI was estimated to be 1 case per 100,000 units of product for the entire study period. A broad range of patients was affected. Consistent with previous descriptions, an acute duration of symptoms (average, 1.4 days) was observed and usually resolved with supportive care. Reactions were observed predominantly in plasma products, both type specific and nontype specific.

Conclusions: This study demonstrates that while TRALI still occurs, clinically meaningful cases are rare. Moreover, TRALI rates remain low despite the increasingly aggressive use of plasma and platelets in the trauma setting.