Discrepancies between estimated and geometrically derived mechanical power in invasively ventilated patients - insights from a randomized clinical trial
In brief
Simplified ventilator power formulas track true mechanical power but show wide error
In 38 passively ventilated ICU patients, 494 paired measurements showed that estimated inspiratory mechanical power correlated strongly to the geometric gold standard, yet Bland-Altman analysis revealed considerable bias and limits of agreement. While the equations discriminate well across most thresholds, the variability cautions against using them interchangeably for clinical decision-making.
- Journal
- Intensive care medicine experimental (Q1)
- Published
- 18 August 2026
- Study design
- Randomized controlled trial
- Evidence level
- Level 1, High (CEBM 1b)
- Authors
- Simon Corrado Serafini, Jan Willem H J Geerts, Ary Serpa Neto, Stephanie S List, Stephan von Düring, Edda Tschernko, et al.
- PMID
- 42611407
- DOI
- 10.1186/s40635-026-00956-8
Why clinicians should know about it
- Picked for Critical Care and Intensive Care Medicine (top studies of the week, 23 August 2026): Mechanical power estimation vs geometric reference
Abstract
BACKGROUND: Mechanical power (MP) quantifies the energy transferred from the ventilator to the respiratory system and is increasingly linked to outcomes in invasively ventilated critically ill patients. Limiting MP may support lung-protective ventilation by integrating key determinants of ventilator-induced lung injury. While geometric MP, derived from pressure-volume loops, is considered the reference standard, it is not readily available at the bedside. Therefore, simplified equations are commonly used, although their agreement remains uncertain. This study evaluates the agreement of previously proposed equations to estimate inspiratory MP compared with a geometric reference. RESULTS: 494 paired values of geometric and estimated MP were collected, in 38 passively ventilated patients during closed-loop ventilation and during conventional ventilation. The median geometric MP was 17.0 [12.3-21.5] J/min. Correlation between geometric and estimated MP ranged from strong to very strong. Agreement between geometric and estimated MP was good, though bias and limits of agreement varied across the different equations. ROC analysis showed excellent discrimination for most equations across all tested cutoffs, with discrimination gradually declining at higher MP levels. CONCLUSION: In passively ventilated critically ill patients, estimated MP showed strong to very strong correlations with the geometric reference. ROC analysis confirmed excellent discrimination, but Bland-Altman analysis revealed considerable variability, suggesting potential limitations in using these equations interchangeably in clinical or research settings. STUDY REGISTRATION: INTELLiPOWER was registered at clinicaltrials.gov (study identifier NCT04827927).
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.