Efficacy and patterns of use of antimicrobial prophylaxis for gunshot wounds in a South African hospital setting : an observational study using propensity score-based analyses

Background: Limited evidence supports the efficacy of antimicrobial prophylaxis (AP) in prevention of gunshot woundrelated (GSW-related) infection in resource restricted areas. At Tygerberg Hospital, South Africa, it is standard care for GSW patients to receive one dose of broad-spectrum AP. For various reasons, this protocol is not consistently followed. This study aimed to assess the efficacy of AP in the reduction of in-hospital GSW-related infection and to identify opportunities for practice improvement.Methods: All patients admitted with GSW over a three-month period were eligible for inclusion. Patients who did and did not receive AP were identified retrospectively the morning of admission; thereafter, data was collected prospectively. Data regarding circumstances of the incident, injury characteristics, type of AP and surgery was obtained. The occurrence of in-hospital GSW-related infection was recorded over 30 days or until discharge. Propensity score matching (PSM) and inverse probability weighting (IPW) methods were utilised to assess the effect of AP on the prevention of GSW-related infection.Results: 165 consecutive patients were assessed, of which 103 received AP according to protocol within 12 hours of admission. PSM showed a reduced in-hospital GSW infection risk of 12% (95% CI, 0.2–24%, p = 0.046) with AP. IPW showed that AP reduced the risk for infection by 14% (95% CI, 3–27%, p = 0.015).Conclusions: Providing AP to GSW patients in a civilian setting appeared to result in a modest but clinically relevant lower risk of in-hospital GSW-related infection. In this study setting, optimisation of AP for all patients with GSWs should significantly lower the burden of wound infection.