Transfusion-associated circulatory overload in ambulatory patients.

BACKGROUND AND OBJECTIVES: Transfusion-associated circulatory overload is a leading cause of transfusion-related adverse events. The frequency and risks for transfusion-associated circulatory overload in ambulatory haematology patients are not known.

MATERIALS AND METHODS: A retrospective cohort analysis of ambulatory patients transfused in a tertiary haematology centre, using medical records and an electronic transfusion database, was undertaken between January and December 2014. Variables studied included age, gender, diagnosis, heart failure, kidney disease and details of transfusions. Transfusion-associated circulatory overload was defined according to proposed International Society of Blood Transfusion criteria. Patients with clinical evidence of hypervolaemia, not meeting the TACO definition and/or who were prescribed otherwise unscheduled diuretic agent, were collectively deemed to be at 'risk of clinically significant hypervolaemia' (ROCSH).

RESULTS: In the study period, 93 ambulatory patients (male = 49, female = 44, mean age = 75·89 ± 11·37 years) attended 715 transfusion encounters, totalling 1536 packed red cell units. No cases of TACO occurred whilst 'ROCSH' events occurred in 57/715 (8%) of transfusion encounters. In a univariate model, age was significantly associated with 'ROCSH', odds ratio = 1·05 (P = 0·017 95%, CI 1·01-1·09) and no factors were significant on multivariate analysis.

CONCLUSIONS: Transfusion-associated circulatory overload occurs infrequently haematology patients receiving ambulatory blood transfusions. To our knowledge, this is the first study to report on occurrence and risk factors for circulatory overload in ambulatory transfusions. This study provides vital baseline data for future prospective studies on this important aspect of haemovigilance.