Background and ObjectivesThere is no consensus on a universally accepted threshold to categorize a patient as multitransfused. In 2019, Colombia established the definition of a multitransfused patient as someone who has received six or more blood components, irrespective of the time frame. This study aims to delineate the characteristics, adverse transfusion reactions (ATRs, definitions according to the International Society of Blood Transfusion [ISBT]) and survival rates in this population.Materials and MethodsWe performed an analysis from the data of all institutions engaged in blood component transfusions at the national level who notified events to the National Information System of Haemovigilance (SIHEVI‐INS), from January 2018 to December 2022. The selection criteria focused on individuals who not only exhibited ATRs but also received six or more blood components.ResultsAmong the 1,784,428 patients who received 6,637,271 blood components, an average of 3.7 components per patient was noted. Concurrently, 8378 ATRs were reported (12.6 ATRs/10,000 transfused components). Within this cohort, 691 patients met the criteria for multitransfusion. Predominantly women (51.8%), these individuals received between 6 and 14 blood components. Out of the 691 multitransfused individuals who experienced ATR, 541 had an allergic reaction. Conversely, out of the 6479 non‐multitransfused individuals who experienced ATR, 3835 had an allergic reaction (odds ratio: 2.49, 95% confidence interval: 2.06–3.0). Notably, 271 multitransfused individuals (39.2%) were documented as deceased, with 76% succumbing within 12 months of encountering their most recent ATR.ConclusionMultitransfused individuals in Colombia, being a high‐risk group, exhibit a heightened susceptibility to allergic reactions, surpassing the frequency observed in other transfusion populations. This underscores the necessity for tailored medical care specific to this group.
