SSI risk after colorectal surgery can be reduced by using oral antibiotic preparation alone

Netherlands: Surgical site infection (SSI) is a common complication after colorectal surgery. A combination of oral antibiotic preparation (OAP) and mechanical bowel preparation (MBP) is usually administered to reduce this risk. Now, a recent review published in the journal Infection Control & Hospital Epidemiology has found that oral antibiotic preparation alone can reduce the risk of SSIs by 50% and is comparable to the combo (of MBP and OAP).

The study led by Tessa Mulder, Utrecht University, Utrecht, The Netherlands, aimed to provide insight into the effectiveness of OAP without MBP on SSI risk using data from observational studies.

For the study, the researchers identified 15 studies with reported data on OAP without MBP, but OAP on its own was the least implemented preparation in almost all the studies. 13 studies used data from 2012 through 2015 from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database, leading them to suspect “a substantial overlap in participants,” so only the largest study was included in their meta-analysis.

Also Read: Prophylactic antibiotics before low-risk operations also prevent surgical site infections

Key findings of the study include:

• SSI risk was significantly reduced when patients received OAP only compared with no preparation (aOR = 0.51).


• Compared with no preparation, SSI risk also was significantly reduced when patients received OAP combined with MBP (aOR = 0.42).


• Results showed no significant difference between MBP with OAP and OAP alone (adjusted OR = 0.7).

Also Read: Preventing surgical site infections: CDC Guidelines 2017

“Nevertheless, all studies reported a protective effect of OAP; therefore, we considered the direction of the effect reliable. The magnitude of the effect, however, could not be directly determined because of the limitations that apply to the ACS-NSQIP database, which we believe affected all the studies performed on these data,” wrote the authors.

“Considering the absence of a beneficial effect of MBP alone, the only rationale for continuation of MBP in combination with OAP is because it was hypothesized that the antibiotics were not effective in an uncleansed colon. Based on our findings, we consider the added value of MBP to be questionable at best,” they concluded.

“High-quality evidence is needed to confirm the efficacy of OAP without MBP. [A randomized controlled trial] that includes an OAP-only arm and is powered to detect a 40% reduction in SSI risk may bring us closer to closing the research gap on the use of OAP and the necessity of MBP."

To read the complete study follow the link: https://doi.org/10.1017/ice.2019.157