BackgroundAirway opening pressure (AOP) detection and measurement are essential for assessing respiratory mechanics and adapting ventilation. We propose a novel approach for AOP assessment during volume assist control ventilation at a usual constant-flow rate of 60 L/min.ObjectivesTo validate the conductive pressure (Pcond) method, which compare thePcond—defined on the airway pressure waveform as the difference between the airway pressure level at which an abrupt change in slope occurs at the beginning of insufflation and PEEP—to resistive pressure for AOP detection and measurement, and to compare its respiratory and hemodynamic tolerance to the standard low-flow insufflation method.MethodsThe proof-of-concept of thePcondmethod was assessed on mechanical (lung simulator) and physiological (cadavers) bench models. Its diagnostic performance was evaluated in 213 patients, using the standard low-flow insufflation method as a reference. In 45 patients, the respiratory and hemodynamic tolerance of thePcondmethod was compared with the standard low-flow method.Measurements and main resultsBench assessments validated thePcondmethod proof-of-concept. Sensitivity and specificity of thePcondmethod for AOP detection were 93% and 91%, respectively. AOP obtained byPcondand standard low-flow methods strongly correlated (r= 0.84,p< 0.001). Changes in SpO2were significantly lower duringPcondthan during standard method (p< 0.001).ConclusionDetermination ofPcondduring constant-flow assist control ventilation may permit to easily and safely detect and measure AOP.Supplementary InformationThe online version contains supplementary material available at 10.1186/s13054-023-04560-0.