Comparison of soap and antibiotic solutions for irrigation of lower-limb openfracture wounds - A prospective, randomized study

Background: Irrigation of open fracture wounds is a commonly performed procedure, and irrigation additives have been used in an attempt to reduce the risk of infection. In vitro and animal studies have suggested that irrigation with detergent solution is more effective than irrigation with a solution containing antibiotic additives. This study was performed to compare the efficacy of those two solutions in the treatment of open fractures in humans. Methods: Adult patients with an open fracture of the lower extremity were prospectively randomized to receive irrigation with either a bacitracin solution or a nonsterile castile soap solution. The patients were followed clinically to assess for the development of infection, healing of the soft-tissue wound, and union of the fracture. Results: Between 1995 and 2002, 400 patients with a total of 458 open fractures of the lower extremity were entered into the study. One hundred and ninety-two patients were assigned to the bacitracin group (B), and 208 were assigned to the castile soap group (C). Outcomes were available for 171 patients with a total of 199 fractures in group B and 180 patients with a total of 199 fractures in group C. The mean duration of follow-up was 500 days. There was no difference between groups B and C in terms of gender, the Gustilo-Anderson grade of the open fracture, the time between the injury and the irrigation, smoking, or alcohol use. There were significant differences in the mean age (thirty-eight compared with forty-two years, p = 0.01), duration of follow-up (560 compared with 444 days, p = 0.01), prevalence of hypotension (23% compared with 14%, p = 0.04), and duration of treatment with intravenous antibiotics (eleven compared with nine days, p = 0.02). An infection developed at thirty-five (18%) of the 199 fracture sites in group B and at twenty-six (13%) of the 199 fracture sites in group C. This difference was not significant (p = 0.2). Bone-healing was delayed for forty-nine (25%) of the 199 group-B fractures and forty-six (23%) of the 199 group-C fractures (p = 0.72). Wound-healing problems occurred in association with nineteen group-B fractures (9.5%) and eight group-C fractures (4%). This difference was significant (p = 0.03).