Preoperative oral antibiotics reduce infections after colorectal resections

Preoperative oral antibiotics reduce surgical site infection following elective colorectal resections, finds this month's issue of the Diseases of the Colon & Rectum.

Surgical site infection is a major cause of morbidity after colorectal resections.

Despite evidence that preoperative oral antibiotics with mechanical bowel preparation reduce surgical site infection rates, the use of oral antibiotics is decreasing.

Currently, the administration of oral antibiotics is controversial and considered ineffective without mechanical bowel preparation.

Dr Jamie Cannon and colleagues examined the use of mechanical bowel preparation and oral antibiotics, and their relationship to surgical site infection rates in a colorectal Surgical Care Improvement Project cohort.

Those receiving oral antibiotics alone had a surgical site infection rate of 8%

Diseases of the Colon & Rectum

The team used Veterans Affairs Surgical Quality Improvement Program preoperative risk, and surgical site infection outcome data linked to Veterans Affairs Surgical Care Improvement Project and Pharmacy Benefits Management data.

The researchers identify factors associated with surgical site infection within 30 days of surgery conducted in 112 Veterans Affairs hospitals.

The team evaluated 9940 patients who underwent elective colorectal resections from 2005 to 2009.

The researchers' primary outcome measured was the incidence of surgical site infection.

Patients receiving oral antibiotics had significantly lower surgical site infection rates.

Those receiving no bowel preparation had similar surgical site infection rates to those who had mechanical bowel preparation only.

The team found that those receiving oral antibiotics alone had a surgical site infection rate of 8%, and those receiving oral antibiotics plus mechanical bowel preparation had a rate of 9%.

In adjusted analysis, the use of oral antibiotics alone was associated with a 67% decrease in surgical site infection occurrence.

Oral antibiotics plus mechanical bowel preparation was associated with a 57% decrease in surgical site infection occurrence.

The research team noted that timely administration of parenteral antibiotics had a modest protective effect, with no effect observed for other Surgical Care Improvement Project measures.

The researchers found that hospitals with higher rates of oral antibiotics use had lower surgical site infection rates.

Dr Cannon's team concludes, "Use and type of preoperative bowel preparation varied widely."

"These results strongly suggest that preoperative oral antibiotics should be administered for elective colorectal resections."

"The role of oral antibiotics independent of mechanical bowel preparation should be examined in a prospective randomized trial."