High-frequency percussive ventilation (HFPV) is a
ventilation modality which has been proved useful as an
alternative to conventional mechanical ventilation. In
clinical practice the ventilator measures the pressure that
represents the sum of the pressure drop due to the
endotracheal tube (ΔPEET) and the pressure dissipated to
inflate lung. From the clinical point of view, it is of
paramount importance to estimate the real amount of ΔPEET.
This study aimed at identifying in vitro the most
adequate model and parameters for estimating ΔPEET of
pediatric endotracheal tube during HFPV, under different
working pressures, percussive frequencies and resistive and
elastic lung loads.
The results show that it is possible to estimate ΔPEET in
pediatric endotracheal tubes by using a simple Blasius’
model, considering the presence of inertance. The Blasius’
model presents the same estimation error as Rohrer’s model
and its coefficients result largely independent from
ventilator settings and lung loads.
