Timing of antibiotic prophylaxis in tourniquet surgery.

It is customary to administer prophylactic antibiotics before exsanguination of the limb and inflation of a tourniquet in extremity surgery. To compare the clinical outcome in lower limb operations when prophylactic antibiotics were administered before versus after limb exsanguination and tourniquet inflation, we randomized patients to the administration of prophylactic antibiotics 5 minutes before exsanguination and inflation of the tourniquet (ABT) and administration of prophylactic antibiotics 1 minute after inflation of the tourniquet (AAT). A total of 106 patients completed the study, including 76 males (71.7%) and 30 females (28.3%). Of the 106 patients, 54 (50.9%) received antibiotics before tourniquet inflation (ABT) and 52 (49.1%) after tourniquet inflation (AAT). Most of the operations (71.7%) involved open reduction and internal fixation of fractures. In the ABT group, 8 wounds (14.8%) developed postoperative infection. In the AAT group, 2 (3.9%) developed wound infection (P = .031). The mean period to wound healing in the ABT group was 4.0 ± 2.3 weeks and was 3.0 ± 0.5 weeks in the AAT group (P = .002). Overall, 100% of the patients in the AAT group were satisfied compared with 85.2% in the ABT group. The difference was statistically significant (P = .005). The results of our study suggest that administration of prophylactic antibiotics before exsanguination and inflation of a lower extremity tourniquet does not give better results than administration of the antibiotic shortly after inflation of the tourniquet.