Ventilator-to-patient energy transfer during insufflation (ET v ) is increasingly recognized as a potential contributor to ventilator-induced lung injury. Current formulations of ET v , however, neglect patient-generated respiratory muscle effort (P mus ), 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 ET v in the presence of respiratory effort using only airway pressure (P aw ) and flow (F aw ) signals. Equations were derived from the single-compartment model of the respiratory system relating the pressure–time product of respiratory muscle pressure (P mus PTP) to ET v during volume-controlled (VCV) and pressure-controlled (PCV) ventilation. Model validation was performed using previously acquired high-fidelity P aw and F aw recordings from two separate cohorts of invasively ventilated patients receiving VCV or PCV. Calculated ET v values were compared with those measured by trapezoidal integration of inspiratory pressure–volume loops. There was excellent agreement between calculated and measured ET v in both modes of ventilation (VCV: R² = 0.99; bias 0.3 ± 0.9 J·min −1 ; PCV: R² = 0.98; bias −0.10 ± 1.94 J·min −1 ). 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.
Guillermo Gutiérrez (2026) studied this question.