Use of serotonergic antidepressants and bleeding risk in orthopedic patients.

BACKGROUND Selective serotonin reuptake inhibitors have been associated with an increased bleeding tendency. Information on the impact of a possible impaired hemostasis associated with the perioperative use of selective serotonin reuptake inhibitors is limited. This study aimed to determine the association between the perioperative use of selective serotonin reuptake inhibitors and the amount of blood loss during surgery and perioperative transfusion requirements. METHODS The authors conducted a retrospective cohort study among patients who underwent elective primary total hip arthroplasty in two hospitals from the period of July 1, 2004 until July 1, 2008. The index group included all users of both serotonergic and nonserotonergic antidepressants. The reference group included a random sample (ratio 1:3) of nonusers. The primary outcome was the amount of intraoperative blood loss. The requirement for blood transfusion was a secondary outcome. The outcomes were adjusted for confounding factors (comorbidity and comedication) using regression techniques. RESULTS The index group included 66 users of serotonergic and 29 users of nonserotonergic antidepressants, and the reference group included 285 patients. After adjustment for confounding factors, mean blood loss during surgery was significantly higher in the users of selective serotonin reuptake inhibitors when compared with the reference group: 95 ml (95% CI 9-181). Mean blood loss in the users of nonserotonergic antidepressants did not differ from the reference group. Users of antidepressants did not have a higher risk for transfusion. CONCLUSIONS Patients undergoing total hip arthroplasty who continue the use of serotonergic antidepressants show a significantly higher, but clinically unimportant, intraoperative blood loss, without an increase in perioperative transfusion requirements.