EVALUATION OF MECHANICALLY VENTILATED PATIENTS (VOLUME-CONTROL AND PRESSURE CONTROL MODES) FOR DEVELOPMENT OF VENTILATOR-INDUCED LUNG INJURY (VILI) USING NORMALIZED MECHANICAL POWER (SIMPLIFIED GATTINONI FORMULA)

Abstract

Mechanical ventilation is essential for the management of acute respiratory failure, but excessive mechanical stress and strain may contribute to ventilator induced lung injury (VILI). Mechanical power integrates multiple ventilatory variables and may provide a comprehensive measure of the energy delivered to the respiratory system. This prospective observational study evaluated the association between normalized mechanical power and VILI in mechanically ventilated adult ICU patients receiving volume control ventilation (VCV) or pressure control ventilation (PCV). One hundred patients requiring invasive mechanical ventilation for more than 24 hours were evaluated over a six month period. Demographic characteristics, clinical scores, and daily ventilator parameters were recorded, and normalized mechanical power was calculated using the simplified Gattinoni formula and predicted body weight. VILI occurred in 28% of patients and was more frequent with VCV than PCV (38% vs 18%, p = 0.027). Normalized mechanical power was significantly higher with VCV than PCV (0.32 ± 0.11 vs 0.27 ± 0.09 J/min/kg PBW, p = 0.013). Increasing normalized mechanical power was associated with progressively higher VILI incidence, with a significant trend across mechanical power categories (p < 0.001). In multivariate logistic regression, normalized mechanical power remained independently associated with VILI (adjusted OR 1.64, 95% CI 1.28 to 2.12; p < 0.001). Receiver operating characteristic analysis demonstrated good discrimination for VILI (AUC 0.82), with a cutoff of 0.31 J/min/kg PBW yielding 78.6% sensitivity and 74.2% specificity. Normalized mechanical power was associated with VILI and adverse clinical outcomes and may have potential utility for risk assessment during lung protective ventilation, although prospective multicenter studies are required for validation.