Infection is a major contributor to morbidity and mortality in patients with penetrating abdominal trauma. Besides the immunosuppression that results from hemorrhage and transfusion, the high risk of infection in abdominal wounds is related to bowel damage. Patients with abdominal stab wounds have approximately a 29 percent chance of small bowel damage and an 18 percent chance of colon injury. In patients with gunshot wounds, the corresponding figures are 45 and 38 percent, but they can be much higher if high-velocity missiles are used. Early antibiotic use has been shown to dramatically reduce the incidence of infection, but antibiotics must be administered within three hours of injury. The duration of antibiotic use remains controversial, particularly the benefit of extending treatment for more than 24 hours after injury. Bozorgzadeh and colleagues conducted a prospective, randomized study that compared the efficacy of antibiotic treatment for 24 hours and for five days in the reduction of infection following abdominal trauma.
The authors studied patients who were admitted to an urban emergency department following abdominal trauma. The 262 men and 38 women had sustained gunshot wounds or stab wounds to the abdomen. Thirty-one of the patients were in shock. All patients underwent laparotomy, and 218 had evidence of bowel injury. All of the patients were treated with intravenous cefoxitin but were randomly allocated to treatment for either 24 hours or five days.
Infection developed in 76 patients (25 percent). No significant differences in the incidence of infection were found between those treated for 24 hours (28 percent) and those treated for five days (23 percent). When infections were analyzed by site and type, no significant differences were found between the two groups for deep abdominal wound, urinary tract, pneumonia, superficial wound or intravenous access site infections. The groups did not differ in postoperative morbidity or length of hospital stay. When multiple factors, including duration of antibiotic use, were analyzed statistically for their contribution to the development of infection, the strongest predictor was colon injury, followed by pre-operative shock and the number of organs injured.
The authors conclude that treatment with antibiotics for 24 hours was as effective as treatment for five days in the prevention of infection following severe abdominal injury.