The microbiology and risk of infection following open, agricultural upper extremity injuries

Purpose This study was designed to determine the microbiology and risk of infection following open, agricultural, upper extremity injuries. Specifically, we sought to evaluate the microbiology of the wounds at the time of initial treatment and the development of any subsequent infections, determine whether the development of subsequent infection was related to injury severity, and clarify whether the microorganisms isolated at the time of initial treatment and development of subsequent infection were susceptible to the initial antibiotic prophylaxis. Methods A retrospective chart review of 214 patients was conducted. Results The initial injuries were classified into 1 of 3 groups, with 1 being the least severe and 3 being the most severe. Twenty-six were type 1 injuries, 94 type 2, and 94 type 3 injuries. Forty patients developed infection following the injury. Seventeen had superficial wound infection, 16 had deep soft tissue infections, and 7 developed osteomyelitis. Six went on to an amputation due to infection. Fifteen of the infections were polymicrobial. The number of patients who developed infection in the first 6 months following injury was 2, 14, and 24 for type 1, 2, and 3 injuries respectively (p =.07). Conclusions Empiric antimicrobial regimens for the management of infection requiring surgical debridement following open upper extremity agricultural injury should be active against staphylococci, aerobic gram-negative bacilli, and anaerobes, but not necessarily against fungi. These antibiotics ideally should be administered on initial presentation of the patient to the emergency department. Prospective studies with emphasis on timely acquisition of cultures and sensitivities are needed to determine optimal prophylactic antimicrobial therapy for these injuries and directed antibiotic regimens for the infections that may develop.