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

Abstract

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 (Pcond) method, which compare the Pcond—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 Pcond 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 Pcond method was compared with the standard low-flow method. Measurements and main results Bench assessments validated the Pcond method proof-of-concept. Sensitivity and specificity of the Pcond method for AOP detection were 93% and 91%, respectively. AOP obtained by Pcond and standard low-flow methods strongly correlated (r = 0.84, p < 0.001). Changes in SpO2 were significantly lower during Pcond than during standard method (p < 0.001). Conclusion Determination of Pcond during constant-flow assist control ventilation may permit to easily and safely detect and measure AOP.

Advanced respiratory mechanics assessment in mechanically ventilated obese and non-obese patients with or without acute respiratory distress syndrome

“…Patients admitted after a cardiac arrest were excluded from the analysis and reported in another publication [ 18 ]. Airway pressure and flow recordings of these patients were used to describe a novel approach to assess AOP [ 19 ].…”

Overestimation of driving pressure by the analysis of the conductive pressure during venous-arterial ECMO: Airway Closure or Intrinsic PEEP?

“…In a recent issue of Critical Care , Haudebourg AF. and colleagues proposed an elegant measurement of the conductive pressure during tidal ventilation (i.e., Pcond) as a valuable tool to evaluate whether apparent DP overestimates actual DP because of AC in critically ill patients undergoing mechanical ventilation [ 4 ].…”