Gut decontamination prevents bronchoscopy-induced bacterial translocation. An experimental study in rats.

Background: Selective gut decontamination is suggested to suppress the gram-negative bacterial overgrowth in the intestine and consequently to reduce bacterial translocation.

Objective: The purpose of the present study is to examine the effects of gut decontamination on bronchoscopy-induced bacterial translocation, and intestinal mucosal injury.

Methods: Forty-five rats were assigned into three groups. Group 1 served as control (n=15). Group 2 (n=15) and group 3 (n=15) underwent bronchoscopy. In addition, group 3 underwent gut decontamination. Gut decontamination was performed two days prior to bronchoscopy with erythromycin and neomycin. Twenty-four hours after bronchoscopy, blood, mesenteric lymph nodes, spleen, liver, ileum and cecum were harvested for bacterial determination. The ileum was also assessed and graded histologically according to Chiu's injury scale.

Results: In the bronchoscopy group, bacterial translocation to the mesenteric lymph nodes was found in 7/15 rats (46.7%), compared to none of the controls (p=0.01). These rats also showed significant evidence of intestinal injury, compared to the controls (mean ranks, 32.7 or 8.5, p<0.0001). On the other hand, gut decontamination prevented bacterial translocation, compared to the bronchoscopy group (p=0.011). However, gut decontamination provided no beneficial effect on the intestinal mucosal injury, compared to the bronchoscopy group. These animals also revealed significant intestinal injury, compared to the controls (mean ranks, 27.8 or 8.5, p<0.0001).

Conclusions: Our data shows that despite no amelioration in bronchoscopy-induced intestinal mucosal injury, gut decontamination has a preventive role for bronchoscopy-induced bacterial translocation.