Study of airflow past endotracheal tubes – effect ventilator flow cycles on transport of mucus

Tracheal airflow in intubated patients presents a range of interesting flow patterns via flow through convoluted geometries. Interaction of the resulting flow structures with the variable, high-viscosity mucus secretions leads mucus pooling which in turn leads to bacterial colonization and secondary infections in patients. The stagnation of mucus is a function of a range of parameters including, but not limited to, the shape and size of the endotracheal tube (ETT) cuff, the inflation pressure of the cuff, and ventilator flow cycles. The present study predicts mucus behavior in intubated patients, via a flow analysis of an intubated upper trachea model. Large-eddy simulations incorporating the respiratory cycle and mucus distribution are carried out and the role of the ventilator flow parameters in mucus leakage is determined. The results will be employed in the development of a predictive, empirical model for mucus leakage which will improve the current experiential selection of the ETT, enable reduced patient monitoring promoting reduced secondary infections in patients, and reduced exposure for clinicians.