A novel method for assessment of airway opening pressure without the need for low-flow insufflation.

Background: Airway 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. Objectives: To validate the conductive pressure (P_cond) method, which compare the P_cond—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. Methods: The proof-of-concept of the P_cond method 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 the P_cond method was compared with the standard low-flow method. Measurements and main results: Bench assessments validated the P_cond method proof-of-concept. Sensitivity and specificity of the P_cond method for AOP detection were 93% and 91%, respectively. AOP obtained by P_cond and standard low-flow methods strongly correlated (r = 0.84, p < 0.001). Changes in SpO₂ were significantly lower during P_cond than during standard method (p < 0.001). Conclusion: Determination of P_cond during constant-flow assist control ventilation may permit to easily and safely detect and measure AOP. [ABSTRACT FROM AUTHOR]