In vitromeasurements of respiratory mechanics during HFPV using a mechanical lung model

Abstract

High-frequency percussive ventilation (HFPV) may be defined as flow-regulated time-cycled ventilation that creates controlled pressure and delivers a series of high-frequency subtidal volumes in combination with low-frequency breathing cycles. In recent years, the usefulness of HFPV has been clinically assessed as an alternative to conventional mechanical ventilation. In the clinical practice, HFPV is not an intuitive ventilatory modality and the absence of real-time delivered volume monitoring produces disaffection among the physicians. For this purpose, it would be useful to develop a monitor able to realize a complete online characterization of high-frequency percussive ventilators and to identify the best combination of their parameters according to the specific pathological situation. This paper describes an innovative acquisition and elaboration system based on the use of new generation pressure transducers presenting high sensitivity and fast response. Such a system is compact and inexpensive, and it allows the user to carry out a more correct online characterization of high-frequency percussive ventilators. This output allowed best real-time ventilatory setting, minimizing the potential baro-volutrauma hazard.

In vitroestimation of pressure drop across tracheal tubes during high-frequency percussive ventilation

“…However inertance may became important during fast breathing, which is the case in HFPV. For this reason we included an inertial term in our models, as also reported in other studies (Guttmann et al 2000, Peslin and Fredberg 1986, Riscica et al 2011, Shumann et al 2008, Sullivan et al 1976. In figure 4 the measured P TT was split into its inertance-dependent ( P TT I) and resistive-dependent ( P TT R) components.…”

A narrative review of advanced ventilator modes in the pediatric intensive care unit

“…Delivered VT can be measured accurately in real time during HFPV with external or portable monitors (59,60). Elastance and resistance can also be estimated through an external monitor during HFPV with acceptable accuracy (61). It is not possible to precisely deliver inhaled nitric oxide during HFPV (62).…”

Comparison of pressure, volume and gas washout characteristics between PCV and HFPV in healthy and formalin fixed ex vivo porcine lungs

“…The compliance, C is a measure of the elasticity of the respiratory system including lung and chest walls (Schranz et al 2014). C is defined as the change in volume for a given applied pressure, In order to obtain R and C from the FOM of the respiratory mechanics, multiple linear regression approach (Kaczka et al 1995, Riscica et al 2011, Schranz et al 2014 was employed. The data samples of measured airway pressure and flow rate, together with volume were used to minimize the sum of squared error (SSE) between measured flow rate and predicted flow rate:…”

“…(2) In order to obtain R and C from the FOM of the respiratory mechanics, multiple linear regression approach (Kaczka et al 1995, Riscica et al 2011, Schranz et al 2014 was employed. The data samples of measured airway pressure and flow rate, together with volume were used to minimize the sum of squared error (SSE) between measured flow rate and predicted flow rate:…”