SSRIs Increase Risk of Blood Transfusion in Patients Admitted for Hip Surgery

Background: Recent studies have shown that an increased bleeding tendency can be caused by Selective Serotonin Reuptake Inhibitors (SSRI) use. We aimed to investigate the occurrence and risk of blood transfusion in SSRI users compared to non-SSRI users in a cohort of patients admitted for hip-surgery. Methods: We conducted a retrospective cohort study of patients who underwent planned or emergency hip surgery from 1996 to 2011 in the Academic Medical Center in Amsterdam. Primary outcome measure was risk of blood transfusion. Secondary outcome measures were pre- and postoperative hemoglobin level. Multivariate logistic regression was used to adjust for potential confounders. Results: One-hundred and fourteen SSRI users were compared to 1773 non-SSRI users. Risk of blood transfusion during admission was increased for SSRI users in multivariate analyses (OR 1.7 [95% CI 1.1-2.5]). Also, pre-operative hemoglobin levels were lower in SSRI users (7.8 +/- 1.0 mmol/L) compared to non-SSRI users (8.0 +/- 1.0 mmol/L) (p=0.042)), as were postoperative hemoglobin levels (6.2 +/- 1.0 mmol/L vs. 6.4 +/- 1.0 mmol/L respectively) (p=0.017)). Conclusions: SSRI users undergoing hip surgery have an increased risk for blood transfusion during admission, potentially explained by a lower hemoglobin level before surgery. SSRI use should be considered as a potential risk indicator for increased blood loss in patients admitted for hip surgery. These results need to be confirmed in a prospective study.