Estimation of the endotracheal tube pressure drop during HFPV: A flow-independent model

Abstract

High frequency percussive ventilation (HFPV) is a non-conventional ventilatory modality which has proven very effective and safe in patients with acute respiratory failure. HFPV ventilator measures airway pressure that represents the sum of the endotracheal tube pressure drop and the tracheal pressure dissipated to inflate a lung. The estimation of the difference between the peak airway and tracheal pressure ΔPp may be very useful to the clinician to avoid lung injury. The aim of this study is to provide a comprehensive solution for estimation of ΔPp in adult endotracheal tubes, by developing a flow-independent model, based on endotracheal tube size, ventilator set parameters (i.e. peak pressures, pulsatile frequencies) and patient’s respiratory system resistance and compliance. The model for the estimation of ΔPp was determined by using the Least Absolute Shrinkage and Selection Operator (LASSO) regularized least-squares regression technique. The identified model was successively assessed on test data set.