Passive reporting greatly underestimates the rate of transfusion-associated circulatory overload after platelet transfusion

Background: Transfusion-associated circulatory overload (TACO) is the second leading cause of reported transfusion-related fatalities in the United States. While its occurrence has been previously investigated after red cell and plasma transfusion, no data are available regarding its association with platelet transfusion. Our goal was to determine the rate of platelet-associated TACO at our university medical centre. Study Design and Methods: This study had retrospective and prospective analyses. The 13-year retrospective analysis served to determine the historical rate of platelet-associated TACO by passive reporting. The 30-day prospective analysis included active surveillance of all non-emergently issued and non-operative platelet recipients ≥16 years old with no transfusions in the previous 6 h determined by analysis of blood bank product issue records. Data collected included demographics, vital signs pre- and posttransfusion, fluid balances, supplemental oxygen use, reports of dyspnoea, and infusion rates. For the prospective analysis, all variables were collected within 24 h of transfusion from the medical record and, when necessary, interviews with care providers and/or patients. Results: In the retrospective analysis, 366 reactions were reported, of which 6 (1·6%) were TACO. The historical rate of TACO was 1:5997 transfused platelet units. During the prospective analysis, 225 eligible patients received a total of 334 units of platelets. The average platelet transfusion volume was 261 ± 26 ml, and the average infusion rate was 391 ± 198 ml/h. Two unreported TACO reactions were discovered and characterized by new-onset hypertension, crackles on lung auscultation, dyspnoea, hypoxia and supplemental oxygen requirements which resolved completely with diuresis. The rate of TACO during this prospective analysis was 1:167 transfused platelet units. Conclusion: Platelet-associated TACO is greatly underestimated by passive reporting in the adult patient population.