Endotracheal tube size to leakage ventilation and tracheal dilatation

This study analyzed the clinical factors with the aim to determine the relationship between endotracheal tube (ETT) size and leakage ventilation (LV) and tracheal dilatation.

All patients with ETT intubation and ventilator support for more than 6 months were retrospectively evaluated. The inner tracheal diameter (TD) was measured over image at the starting and 6 months after ventilator initiated. We compared the clinical factors, outcomes and complications between patients with and without LV, as well as with and without a TD enlarging more than 25% after 6 months (TDn). Logistic regression analyses of factors related to the LV and TDn were performed. The cut-off points of the ratio of outer diameter of ETT (OD) to TD were set and evaluated for their accuracy of predicting LV and TDn.

689 patients were enrolled initially and eventually 199 patients were included, of which 52 and 66 patients were identified to have LV and TDn, respectively. Patients with LV had a higher peak inspiratory pressure (PIP), smaller initial ETT OD/TD and higher incidence of pneumonia. Patients with TDn had a higher PIP, larger initial OD/TD and higher incidence of pneumonia. A higher PIP and smaller initial OD/TD were significantly related to LV and a higher PIP and larger initial OD/TD were significantly related to TDn. The incidence of LV and TDn was higher in patients with an initial OD/TD less than 0.51 and more than 0.54, respectively.

The initial ETT OD/TD ratio is a predictor for LV and TDn.