Abstract Rationale Ventilator dyssynchrony is frequent in patients on mechanical ventilation (MV) and has been associated with worsened clinical outcomes. The goal of this study is to evaluate the association between breath stacking (BS) events due to reverse triggering (RT) and double triggering (DT) and 28-day mortality. Methods This was a post-hoc analysis of the EPVent2 trial. Daily MV waveforms ranging from baseline through day three were manually analyzed by three blinded authors. The total number of breaths and the number of RT and DT events leading to BS were collected. Maximum esophageal pressure (Pes) and transpulmonary pressure (PL) swings and the tidal volume (Vt) of normal, RT and DT breaths, for an average of up to 10 breaths per recording, were obtained. Interrater agreement was performed periodically to ensure appropriate data collection. A fourth author was involved in case of disagreements. An adjusted generalized linear mixed model (GLMM) approach was used to investigate the association between mortality and the dyssynchrony index (DI) for each dyssynchrony type. Results A total of 198 patients were included in the analysis, with a mean age of 55.8±15.6 years and a mean SOFA score of 7.4±3.7. The average time of recording per patient per day was 8 (IQR 4-19) minutes for a total of 30,608 minutes and 250,162 breaths. The interrater agreement between the three investigators ranged from 0.97 to 1.00. Among patients with RT and/or DT, the mean DI was 3.05%±6.6%. The Pes, PL and Vt/kg above a normal passive breath in patients with RT events was 6.05 cmH2O (IQR 3.56-8.89, p 0.001), 4.35 cmH2O (IQR 1.8-7.38, p 0.001) and 2 mL/kg (IQR 1.2-4.4, p 0.001), respectively. The Pes, PL and Vt/kg above a normal active breath in patients with DT events was 4.35 cmH2O (IQR 1.8-10.51, p 0.001), 2.5 cmH2O (IQR -0.27-7.61, p 0.001) and 1.1 mL/kg (IQR 0.1-3, p 0.001), respectively. In the GLMM analysis, there was no association between DI for RT, DI for DT, and DI for RT and DT with mortality (p = 0.95, p = 0.78 and p = 0.91, respectively). Results are available in Table 1. Conclusion Although BS events lead to worsened ventilatory mechanics, they do not correlate with a higher mortality according to our findings. Further research is required to evaluate whether dyssynchrony is a marker of severity, simply a nuisance in some patients or an actual cause of lung injury that could potentially lead to worsened clinical outcomes. This abstract is funded by: None
Gulluoglu et al. (Fri,) studied this question.