Pressure reconstruction by eliminating the demand effect of spontaneous respiration (PREDATOR) method for assessing respiratory mechanics of reverse-triggered breathing cycles

Abstract

Purpose: Patient-specific respiratory mechanics can be used to guide mechanical ventilation therapy. However, even in controlled ventilation modes, underlying respiratory mechanics can be masked by spontaneous breathing efforts. The aim of this study is to accurately assess respiratory mechanics for breathing cycles affected by these spontaneous breathing efforts. Methods: A pressure reconstruction by eliminating the demand effect of spontaneous respiration (PREDATOR) method is used to reconstruct pressure profiles to assess underlying respiratory mechanics (breath specific elastance and resistance). The method is tested on both simulated and clinical data comprising n=264 breaths. Results: Using simulated data, the standard deviation of identified elastance (σ=0.168) and resistance (σ=0.053) are both significantly smaller using PREDATOR (σ=1.009 and σ=0.348) (p<0.05 for both) compared to standard methods. Variability in identified elastance is significantly decreased in clinical data tested (p<0.05). Median [IQR] of the robust coefficient of variation in elastance for each pressure level using PREDATOR is 0.0518 [0.0278–0.0668] compared to 0.1211 [0.0854–0.1783] of the standard algorithm. Conclusions: The PREDATOR method provides a more accurate respiratory mechanics identification in the presence of spontaneous breathing. It provides the opportunity to use respiratory mechanics to guide mechanical ventilation therapy.