Preoperative Antibiotics Influence Culture Yield in the Treatment of Hand, Wrist, and Forearm Infections.

Unlabelled: When treating upper-extremity infections, clinicians frequently must decide whether to initiate antibiotics or delay them with the goal of optimizing culture yield at the time of surgical debridement. The purpose of this study was to determine whether the administration of preoperative antibiotics affects intraoperative culture yield and whether there is a "safe" interval prior to culture acquisition within which antibiotics can be administered without affecting culture yield.

Methods: We conducted a retrospective review of 470 consecutive patients who underwent debridement for a presumed acute infection of the hand, wrist, or forearm at a single tertiary care center between January 2015 and May 2020. Data including patient demographics, mechanism of infection and affected body part(s), and details of antibiotic administration, including type and timing with respect to culture acquisition, were collected.

Results: Three hundred and forty-one patients (73%) received preoperative antibiotics prior to debridement and culture acquisition. The rate of positive cultures among patients who received preoperative antibiotics was 81% compared with 95% among patients who did not receive preoperative antibiotics (p < 0.01; odds ratio, 4.73). Even a single dose of antibiotics imparted a significantly increased risk of obtaining negative intraoperative cultures, and an incremental increase in the likelihood of obtaining negative cultures was seen with each preoperative dose given up to 7 doses. We did not identify a "safe" interval of time between antibiotic administration and culture acquisition such that culture yield was not affected.

Conclusions: Patients who received preoperative antibiotics for the treatment of upper-extremity infections were approximately 5 times more likely to have negative cultures at the time of debridement than those who did not receive preoperative antibiotics. This effect persisted regardless of the number of doses given or the interval between antibiotic administration and culture acquisition.

Level Of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.