OBJECTIVE: Bowel preparation prior to colectomy remains controversial. Our hypothesis is that mechanical bowel preparation with oral antibiotics (compared to without) is associated with lower SSI rates.
METHODS: 24 Michigan hospitals participated in the Michigan Surgical Quality Collaborative - Colectomy Best Practices Project. Standard ACS NSQIP peri-operative data, bowel preparation process measures and C.difficile colitis outcomes were prospectively collected. Among patients receiving mechanical bowel preparation, a logistic regression model generated a propensity score that classified cases into receiving an oral antibiotic or not. A SAS Greedy macro was used for matching cases.
RESULTS: Overall, 2062 elective colectomies occurred between January 2008 and June 2009. No bowel prep was given to 233 patients (11.3%) and they were excluded from the analysis; 49.6% received a mechanical prep and 36.4% received a mechanical prep and oral antibiotics. Propensity analysis created 382 paired cases (differing only in receiving oral antibiotics). Patients receiving oral antibiotics were less likely to have any SSI (4.5% vs.11.8%, p = 0.0001), to have an organ space infection (1.8% vs. 4.2%, p = 0.044) and to have a superficial SSI (2.6% vs. 7.6%, p = 0.001). Patients receiving bowel prep with oral antibiotics were also less likely to have a prolonged ileus (3.9% vs. 8.6%, p = 0.011) and had similar rates of C. difficile colitis (1.3% vs. 1.8%, p = 0.58).
CONCLUSIONS: Most patients in Michigan still receive mechanical bowel preparation prior to colectomy. Oral antibiotics at the time of mechanical bowel preparation may reduce the incidence of SSI.