Canadian Association of General Surgeons Evidence Based Reviews in Surgery. 9. Risk factors for retained foreign bodies after surgery.

Question: What are the identifiable risk factors for retained foreign bodies in surgical patients? Design: Case–control study. Setting: A malpractice insurance agency and 10 hospitals in the state of Massachusetts from January 1, 1985 to January 1, 2001. Participants: Fifty-four patients with a total of 61 retained foreign bodies, and 235 control patients. Assessment of risk factors: Risk factors considered included a change in nursing personnel during surgery, excessive loss of blood, lack of complete count of sponges and instruments, fatigue of the surgical team from the lengthiness or lateness of the procedure and urgency of the surgery, obesity, unexpected intraoperative developments, the involvement of multiple surgical teams, and the performance of more than 1 major procedure at a time. Main outcome measure: Retained sponge or instrument after a surgical procedure. Results: Multivariate analysis showed that 3 factors were significant: emergency surgery (risk ratio 8.8, 95%CI 2.4–31.9), unplanned change in the operation (RR 4.1, 95%CI 1.4–12.4) and body mass index (RR for each unit increment 1.1, 95%CI 1.0–1.2). Conclusions: The risk of retaining a foreign body after surgery is significantly increased in emergency surgery with unplanned changes in the procedure and in patients with a high body mass index.