Effects of Tracheal Tube Size on Pulmonary Aspiration Different Endotracheal Tube Size Influences Pulmonary Aspiration

The use of a high-volume and low-pressure (HVLP) endotracheal cuff has reduced the cuff-induced tracheal damage because the cuff conforms passively to tracheal contours as it expands during inflation and the cuff inflation pressure is assumed to be equal to cuff-to-trachea pressure. However, longitudinal folds of a HVLP cuff occur on inflation within the trachea, as the diameter of the cuff is greater than that of the trachea, and these folds provide channels for an aspiration or gas leakage.

Silent aspiration of upper airway secretions has been reported in patients undergoing general anesthesia and in the intensive care unit (ICU). A previous study reported the 83% aspiration of subglottic dye detected by bronchoscopy in anesthetized patients, and other study of intubated patients with HVLP cuffs in the ICU showed 87% aspiration rate.

Intubation-related (ventilator associated pneumonia) pneumonia is a leading cause of prolongation of hospital stay, mortality and morbidity during the postoperative period and in the ICU. Therefore, it is important to achieve a better seal around the cuff without tracheal damage, which would reduce the incidence of pneumonia in intubated patients.

A previous benchtop study demonstrated that the leak around the cuff is minimized when the endotracheal tube size is small relative to the size of the trachea. In the current study, we assess the influence of different HVLP endotracheal tube size on fluid leakage around the cuff in a benchtop model and in anesthetized patients.