Mechanical power in mechanical ventilation and its association with ventilator-induced lung injury: A systematic review

Abstract

Background: Mechanical power (MP) quantifies the total energy delivered from the ventilator to the respiratory system per unit time, integrating tidal volume, airway pressures, respiratory rate, and flow. MP has been proposed as a surrogate marker of ventilator-induced lung injury (VILI), but the consistency and generalizability of this association across patient populations remain uncertain.

Objectives: To provide the most comprehensive systematic evaluation to date of the relationship between MP and VILI-related outcomes in adult patients receiving invasive mechanical ventilation.

Methods: We conducted a systematic review following PRISMA guidelines. Four databases (PubMed, Embase, Scopus, Web of Science) were searched for original studies reporting MP and clinical outcomes related to VILI. Risk of bias was assessed using RoB 2.0 and ROBINS-I tools. Certainty of evidence was rated using the GRADE approach.

Results: Forty-six studies including 314,823 patients were analyzed. Forty (87 %) demonstrated a statistically significant association between higher MP and adverse outcomes (mortality, prolonged ventilation, or ICU stay). Threshold effects were identified in 23 studies, most consistently between 14 and 18 J/min. Normalized MP (e.g., per predicted body weight or well-aerated lung volume) improved prognostic performance in selected cohorts. Despite heterogeneity and mostly observational designs, the overall signal was robust across diverse populations and clinical contexts.

Conclusions: This review establishes mechanical power as a consistent and clinically relevant predictor of adverse outcomes in mechanically ventilated adults. By synthesizing >300,000 patients, it provides the most reliable evidence base to date, identifies reproducible thresholds, and highlights the importance of normalization strategies. These findings suggest that MP could complement tidal volume and driving pressure in lung-protective ventilation and define priorities for future prospective trials.

Keywords: ARDS; Lung protection; Mechanical power; Mechanical ventilation; Ventilator-induced lung injury.