Research Letter
Pacific Coast Surgical Association
September 25, 2024
Antibiotic Prophylaxis for Surgical Site Infection After Traumatic Hollow Viscus Injury
Janelle Cyprich, Amy H. Kaji, Alexandra Moulton, et al
JAMA Surg. Published online September 25, 2024. doi:10.1001/jamasurg.2024.3827
Surgical site infection (SSI) is a major cause of morbidity after trauma laparotomy. Hollow viscus injury (HVI) increases risk of SSI.1 Current guidelines recommend no more than 24 hours of antibiotic prophylaxis (PPX) after traumatic HVI,2 but whether guideline adherence is associated with risk of SSI is unknown. This study investigates the association between PPX duration and SSI after traumatic HVI.
Methods
This retrospective cohort study was conducted at an academic level I trauma center. The Harbor-UCLA Institutional Review Board deemed it exempt and waived the need for informed consent. We followed the STROBE reporting guideline.
Adults (aged 18-79 years) with blunt or penetrating HVI who underwent laparotomy within 24 hours of presentation from December 1, 2014, to May 31, 2023, were included. Self-reported race and ethnicity were from the electronic medical record. Those who died within 48 hours of presentation or had a delayed presentation after injury were excluded.
We defined SSI according to established guidelines.3 Risk factors for SSI were identified using univariable analysis. Subgroup analysis of patients receiving 10 days or less of postoperative antibiotics was performed to evaluate PPX duration as a risk factor. Multivariable logistic regression was performed to evaluate independent associations between PPX duration and SSI. Data were analyzed using SPSS, version 29.0 (IBM Corporation). A 2-sided P < .05 was considered significant by χ2 or Mann-Whitney U test.
Results
A total of 302 patients were included (median [IQR] age, 31 [26-24] years; 262 men [86.8%] and 40 women [13.2%]). Most patients (261 [86.4%]) sustained penetrating injuries, the majority being gunshot wounds (214 [82.0%]). Shock was present in 68 of 285 patients (23.9%), defined as presentation shock index (heart rate divided by systolic blood pressure)≥0.9. Damage control laparotomy was performed in 100 patients (33.1%). The most common antibiotics administered were ceftriaxone and metronidazole (225 of 302 [74.5%]). Surgical site infection occurred in 106 patients (35.1%), of whom 18 (17.0%) developed an isolated superficial SSI without organ space involvement.
Demographics and perioperative characteristics were compared between patients with and without SSI (Table). The SSI risk factors identified on univariable analysis for inclusion in our multivariable model included prior abdominal surgery (14 [13.2%] vs 9 [4.6%]; P = .007), penetrating trauma (98 [92.5%] vs 163 [83.2%]; P = .02), Injury Severity Score (median [IQR], 21.5 [14.0-29.0] vs 13.0 [9.0-21.5]; P < .001), number of HVIs (median [IQR], 4 [2-7] vs 2 [1-4]; P < .001), ostomy creation (19 [17.9%] vs 12 [6.1%]; P = .001), intraoperative blood transfusion (median [IQR], 4.5 [0.0-12.0] vs 0.5 [0.0-4.0] packed red blood cell units; P < .001), and intraoperative temperature (median [IQR], 35.0 [34.2-35.6] vs 35.5 [34.8-36.1] °C; P < .001).
Subgroup analysis of patients receiving 10 days or less of antibiotics found no association between PPX duration and development of SSI (Figure). On multivariable analysis, antibiotic duration of 24 hours or less was not associated with increased SSI (adjusted odds ratio, 1.2; 95% CI, 0.8-1.8).
Discussion
In this cohort study, PPX of 24 hours or less was not associated with an increased risk of SSI, even after adjusting for known risk factors. Current guidelines2 are based primarily on a prospective study4 showing no difference in SSI between 1 and 5 days of postoperative ampicillin-sulbactam after penetrating HVI. That study reported an SSI incidence of 9%, significantly below the expected rate of 20% to 40% for class III/IV wounds.5,6 This discrepancy raises questions about the evidence behind current guidelines and may account for variable adherence. Our findings support current PPX guidelines,2 even in a population with a higher incidence of SSI.
This study is limited by its single-center, retrospective design. Indications for initial antibiotic administration were variably documented; thus, only patients who received continuous antibiotic administration postoperatively were included in the PPX duration subanalysis. Our study represents one of the largest cohorts with traumatic HVI to date. Prospective studies are needed to validate PPX guidelines for traumatic HVI and ultimately improve adherence.
