Session VII - Polytrauma
Sat, 10/9/04 Polytrauma, Paper #41, 11:17 am
A Prospective Randomized Comparison of Soap Solution and Antibiotic Solution for Irrigation of Lower Extremity Open Fracture Wounds
Purpose: Wound irrigation, along with debridement, is an essential first step in the treatment of open fractures. The goal of irrigation is to cleanse the wound and decrease the load of viable bacteria present so as to lower the incidence of infection. A variety of different irrigation additives have been advocated, including antibiotics, antiseptics, and detergents. Animal studies of infected or contaminated wound models have suggested that a detergent additive is more effective than antibiotic solution at reducing the infection rate. The purpose of this study was to compare rate of infection, non- or delayed union, and wound healing difficulties after open lower extremity fractures were irrigated with either antibiotic solution or soap solution.
Methods: Institutional Review Board approval of the protocol was obtained. Pre-study power calculations were performed to set sample size at 200 fractures per group. Consenting adult patients with open lower extremity fractures were randomized to irrigation with bacitracin solution (50,000 Units /3 L saline solution) or Castile soap solution (~80 cc /3 L saline solution). Volume was determined by a protocol based on Gustillo/Anderson grading. Irrigation was performed by power pulsatile lavage. Pre- and intraoperative data were collected by investigators on standardized data collection instruments. Outcome data were collected in the course of standard injury follow-up by monitoring medical records. The occurrence of infection was defined by the treating physician and identified by the requirement for treatment. Wound healing problems were defined as dehiscence or necrosis of closure or coverage not secondary to underlying infection. Patients were observed until they were discharged from care with wounds and fractures healed. Statistical analysis was performed with Systat 5.0.
Results: Between January 1995 and September 2002, 400 patients with 458 open lower-extremity fractures were entered into the study. The bacitracin group (B) received 192 patients, and the Castile soap group (C) received 208. Fifty-seven patients died or were lost with less than 6 months of follow-up. Outcomes were available for 166 patients with 194 fractures in group B, and 177 patients with 195 fractures in group C. The mean duration of follow-up was 477 days (range, 35 to 2422). There was no difference between groups B and C in sex distribution (~60% male), Gustillo/Anderson grade (42% vs. 48% grade III), average injury to irrigation time (6.08 vs. 6.31 hours), smoking history (48% vs. 44%), or in alcohol use (52% vs. 51%). There were differences in mean age (38 vs. 42 years, P = 0.01), duration of follow-up (527 vs. 430 days, P = 0.02), and presence of hypotension (23% vs. 15%, P = 0.04). Infection occurred in 35 of 194 fractures (18%) in group B and in 26 of 195 fractures (13%) in group C. This difference was not significant according to the Fisher exact test (P = 0.212). Delay in bone healing occurred in 50 of 194 group B fractures (26%), and 46 of 195 group C fractures (24%); according to the Pearson chi square test, P = 0.51. Wound healing problems occurred in 17 of 194 (9%) group B fractures and 7 of 195 (4%) group C fractures; according to the Fisher exact test, P = 0.37.
Conclusions/Significance: Although there were more infections and nonunions in the antibiotic group, those differences were not statistically significant. There were more wound healing problems in the antibiotic irrigation group. Irrigation with a non-sterile liquid soap solution is at least as safe and effective as antibiotic solution.