Oral chlorhexidine and microbial contamination during gastroscopy. Implications for transgastric surgery. A randomised trial.

Background: A concern associated with transgastric natural orifice transluminal endoscopic surgery (TG-NOTES) is the risk of contamination and intraabdominal infection with microbes introduced from the access route. An effective decontamination regimen is needed before the technique can be implemented in routine clinical practice. The aim of this study was to evaluate the effect of oral decontamination with chlorhexidine on? microbial contamination of the endoscope during a gastroscopy.

Methods: In a prospective randomised single blinded clinical trial the effect of chlorhexidine mouth rinse was evaluated. As a surrogate for the risk of intraabdominal contamination during TG-NOTES, microbial contamination of the endoscope during gastroscopy was examined. Patients referred to gastroscopy were assessed for eligibility and randomised to either chlorhexidine or no mouth rinse after oral and written consent had been obtained. Culture samples were collected from gastric aspirate and endoscope. Analyses of sample cultures were performed blinded to the respective allocation. The primary outcome measure was colony forming units (CFU/ml) in the endoscope samples. Secondary outcome measures were species specific effect of chlorhexidine on microorganisms with abscess forming capabilities and the effect of proton pump inhibitor (PPI) treatment on CFU measurements.

Results: A total of 160 patients were approached of which 109 were included in the study. Due to exclusions after randomisation, 100 participants were available for final analyses. Chlorhexidine mouth rinse resulted in a significant reduction of CFU/ml in the endoscope samples (p ((equals)) 0.001). There was no species specific effect and microorganisms with abscess forming capabilities were still equally present in both groups. PPI treatment was associated with significantly higher CFU counts in both the gastric aspirate (p ((equals)) 0.004) and endoscope samples (p ((equals)) 0.049).

Conclusion: Chlorhexidine mouth rinse was effective in reducing microbial contamination of the gastroscope, but microorganisms with abscess forming capabilities were still present. Oral chlorhexidine needs to be combined with other measures for an effective decontamination regimen prior to TG-NOTES. PPI treatment significantly increased CFU/ml and should be discontinued before TG-NOTES.