Frequency of Acute Adverse Transfusion Reactions at King Saud Medical City, Riyadh, Saudi Arabia

Background: Blood transfusion is a life-saving intervention but is associated with adverse reactions in a subset of recipients. An acute transfusion reaction (ATR) is defined as any unfavorable response occurring within 24 h of blood component administration. This retrospective observational study aimed to determine the frequency and characteristics of ATRs at King Saud Medical City (KSMC), Riyadh, Saudi Arabia. Methods: We conducted a retrospective study using data from the Transfusion Medicine Laboratory (TML) at KSMC between January 2019 and December 2023. Demographic, clinical, and laboratory data from 238 confirmed ATR records were analyzed using SPSS v21.0. Chi-square, Mann-Whitney U, and risk ratio analyses were performed; p < 0.05 was considered statistically significant. Results: Among 238 patients (59.2% female; mean age 33.7 ± 18.5 years), allergic reactions were the most frequent ATR (70.2%, n = 167), followed by febrile non-hemolytic transfusion reactions (FNHTRs); (24.4%, n = 58). Packed red blood cell (PRBC) transfusion was the most commonly implicated product (82.4%; n = 196; p < 0.001). Fever, rash, itching, and chills were significantly associated with specific reaction subtypes (p < 0.001). The pattern of post-transfusion workup differed significantly across reaction types (p < 0.001). Age, gender, ward distribution, and reaction timing were not significant predictors of ATR occurrence. Conclusions: Allergic reactions are the predominant ATR form at KSMC. Demographic variables are not reliable predictors of ATR. Strengthening hemovigilance systems and clinician education is recommended to improve transfusion safety.