A trial of ciprofloxacin and metronidazole vs gentamicin and metronidazole for penetrating abdominal trauma.

OBJECTIVES To determine whether a combination of ciprofloxacin hydrochloride and metronidazole hydrochloride would be as effective or more effective than a combination of gentamicin sulfate and metronidazole hydrochloride for preventing infection in patients with penetrating abdominal trauma, to evaluate the factors associated with increased risk of infection, and to determine the serum peak and trough levels of gentamicin with the dosage regimen of 2.5 mg/kg every 12 hours. DESIGN Randomized double-blind study. SETTING Level I trauma center. PATIENTS Eighty-four patients with penetrating intra-abdominal injuries (gunshot wound, 69; stab wound, 15) thought to require laparotomy. INTERVENTIONS The patients were randomized during treatment in the emergency department to be given a combination of ciprofloxacin hydrochloride, 400 mg every 12 hours, and metronidazole hydrochloride, 500 mg every 6 hours, or a combination of gentamicin sulfate, 2.5 mg/kg every 12 hours, and metronidazole hydrochloride, 500 mg every 6 hours. RESULTS Of 68 patients with intra-abdominal injuries who could be observed for at least 48 hours after laparotomy, posttraumatic infections developed in 12 (18%), and nosocomial infections developed in 6 (9%). The incidence of posttraumatic infections in patients who were given gentamicin and metronidazole (5/33 [15%]) was not significantly lower than the incidence in patients who were given ciprofloxacin and metronidazole (7 of 35 [20%]; P=.75). The presence of any infection increased the mean+/-SD length of hospital stay from 8.7+/-3.5 days to 23.3+/-10.9 days and increased the mean+/-SD hospital charges from $24 507+/-$9860 to $104920+/-$49083 (P<.001). Univariate analysis showed the factors most significantly associated with infection were as follows: (1) the use of blood transfusions (P<.001), (2) the penetrating abdominal trauma index of 35 or more (P<.002), (3) injury to the colon requiring a colostomy (P=.004), and (4) a trauma score of less than 12 (P<.02). Multivariate analysis showed the only significant factor was the receipt of blood transfusions (F=10.165; P<.005). CONCLUSIONS Ciprofloxacin and gentamicin, each in combination with metronidazole, were equivalent in their ability to prevent infections after penetrating abdominal trauma; other factors, especially the receipt of blood transfusions, had much more effect on the incidence of infection. Infection greatly increases the length of hospital stay and hospital charges. The use of an increased dosing regimen of 2.5 mg/kg every 12 hours of gentamicin sulfate was effective at obtaining a therapeutic peak serum concentration.