Noninvasive quantification of energy transfer during mechanical ventilation

Document Type

Journal Article

Publication Date

4-1-2026

Journal

Journal of applied physiology (Bethesda, Md. : 1985)

Volume

140

Issue

4

DOI

10.1152/japplphysiol.01197.2025

Keywords

energy transfer; mechanical ventilation; pressure-time product; respiratory effort; respiratory mechanics

Abstract

Ventilator-to-patient energy transfer during insufflation (ET) is increasingly recognized as a potential contributor to ventilator-induced lung injury. Current formulations of ET, however, neglect patient-generated respiratory muscle effort (P), a potentially important modifier of ventilator energy delivery. Accordingly, the aim of this study was to develop and validate mathematical expressions that quantify breath-by-breath ETv in the presence of respiratory effort using only airway pressure (P) and flow (F) signals. Equations were derived from the single-compartment model of the respiratory system relating the pressure-time product of respiratory muscle pressure (PPTP) to ET during volume-controlled (VCV) and pressure-controlled ventilation (PCV). Model validation was performed using previously acquired high-fidelity P and F recordings from two separate cohorts of invasively ventilated patients receiving VCV or PCV. Calculated ET values were compared with those measured by trapezoidal integration of inspiratory pressure-volume loops. There was excellent agreement between calculated and measured ETv in both modes of ventilation (VCV: R = 0.99; bias 0.3 ± 0.9 J·min; PCV: R = 0.98; bias -0.10 ± 1.94 J·min). These results demonstrate that ventilator-to-patient energy transfer during controlled mechanical ventilation can be quantified accurately and noninvasively on a breath-by-breath basis using airway signals alone. The developed model also provides a physiological basis for real-time assessment of insufflation energy dynamics. This study presents and validates a noninvasive method that uses only airway pressure and flow signals to dynamically quantify energy transfer to mechanically ventilated patients while accounting for respiratory effort. Equations derived from a classic one-compartment model accurately predicted individual breath energy transfer during volume- and pressure-controlled ventilation. The method provides a physiological framework to explore, in real-time and non invasively, the dynamics and clinical significance of ventilator-to-patient energy transfer.

Department

Medicine

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