AUTHOR=Tontu Furkan , Rahimi Payam , Çelik Yasemin , Tontu Esra , Çukurova Zafer , Aşar Sinan TITLE=Adjusting inspiratory rise time alters mechanical power in acute respiratory distress syndrome: opposing effects in pressure-controlled and volume-controlled ventilation modes JOURNAL=Frontiers in Medicine VOLUME=Volume 13 - 2026 YEAR=2026 URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2026.1748263 DOI=10.3389/fmed.2026.1748263 ISSN=2296-858X ABSTRACT=BackgroundMechanical power (MP), a predictor of ventilator-induced lung injury (VILI), is influenced by ventilatory parameters such as inspiratory rise time (Tslope). While Tslope affects the flow profile, its impact on MP in acute respiratory distress syndrome (ARDS) has not been thoroughly studied, particularly using the geometric method.MethodsIn this prospective observational study, 30 deeply sedated and paralyzed ARDS patients were ventilated in both volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV) modes using a Maquet Servo-u ventilator. At inspiratory-to-expiratory (I:E) ratios of 1:2 and 1:1, Tslope was adjusted from 5 to 15%, and pressure–volume (P–V) loop screenshots were captured. Geometric mechanical power (MPtotal) was calculated based on the area enclosed by the P–V loops. A total of 720 images were analyzed.ResultsIn VCV mode, increasing Tslope from 5 to 15% led to a statistically significant increase in MPtotal: 0.8 J/min (5%) at I:E 1:2 and 0.1 J/min (1%) at I:E 1:1. Conversely, in PCV mode, Tslope prolongation resulted in a significant decrease in MPtotal: 1.8 J/min (12.5%) at I:E 1:2 and 1 J/min (7%) at I:E 1:1. No intrinsic PEEP was detected.ConclusionModifying Tslope alters MPtotal in opposing directions in PCV and VCV modes. In VCV, prolonging Tslope from 5 to 15% increased MP, whereas increasing the I:E ratio from 1:2 to 1:1 reduced MP. In PCV, prolongation of Tslope from 5 to 15% decreased MP by more than 1 J/min, and changes in the I:E ratio exerted minimal effects on MP.