Does rigid bronchoscopy induce bacterial translocation? An experimental study in rats

Although some reports suggest that bronchoscopy induces bacterial translocation (BT), the mechanisms of BT remain unclear.

We aimed to assess whether bronchoscopy or hypoxemia during bronchoscopy is responsible for BT.

We evaluated 24 rats divided into three subgroups: the control group (group 1, n = 8); the rigid bronchoscopy group (group 2, n = 8), and the group receiving bronchoscopy + mechanical ventilation (group 3, n = 8). Oxygen saturation (SaO(2)) was measured during the bronchoscopic procedure. Blood and tissue cultures from mesenteric lymph nodes (MLNs), liver, spleen and cecal contents were obtained 24 h following bronchoscopy.

In group 2, SaO(2) was significantly lower than in groups 1 and 3 (p < 0.01). In group 2, BT significantly increased (6/8, 75%; p < 0.01 vs. group 1, and p < 0.05 vs. group 3). The main site of translocation was MLNs (6/8, 75%) in group 2, while BT was detected in only 1 rat in group 3 (1/8, 12.5%).

Hypoxemia during rigid bronchoscopy resulted in intestinal mucosal damage in a rat model. Hypoxemia may have been the trigger for BT from the intestine following bronchoscopy.