Abstract
Endotracheal tubes (ETT) of intubated patients are constantly challenged with abundant bacteria-laden secretions. These bacteria may rapidly form a well-organized structure, referred to as biofilm, on the inner surface of the ETT. Secretions become very tenacious and are difficult to clear. However, bacteria and secretions can detach spontaneously or become dislodged by suction catheters and enter the lungs, providing a source of infection. Recently, several strategies have been developed to prevent accumulation of mucus and bacterial colonization of the respiratory circuit. In this review, we summarize published studies on antimicrobial ETT-coated and clearance devices.
Numerous antimicrobial-impregnated ETTs have been designed with bactericidal/static properties to prevent adhesion of bacteria on ETT surfaces. Several in vitro experiments and animal-studies have shown success in the prevention of bacterial colonization through the use of these specialized ETTs. At present, only two ETT coatings, silver-hydrogel and silver-sulfadiazine in polyurethane, have been tested in clinical trials. Both coatings have been shown to prevent/lower bacterial colonization of the ETT, while only the silver-hydrogel coating decreased bacterial colonization of lungs in a large multicenter study.
Another innovative approach is to reduce contaminated-secretions in the ETT-lumen with novel medical devices designed to retrieve accumulated-mucus from the ETT. The mucus shaver and the mucus slurper are two devices intended to reduce loaded-bacteria secretions from within the ETT. While experimental and preliminary clinical trials are promising, there are no large clinical trials showing outcome benefits.
Keywords: Bacterial colonization, endotracheal tube, mechanical ventilation, ventilator associated pneumonia.