Impact of Reverse Triggering Dyssynchrony during Lung-Protective Ventilation on Diaphragm Function: An Experimental Model

Managing respiratory muscle weakness during weaning from invasive ventilation

“…Whether intense respiratory efforts could indeed induce diaphragm injury in patients with acute respiratory failure and whether this potential muscle injury could be translated into diaphragm dysfunction is not established. Under mechanical ventilation, it has been suggested that patient–ventilator asynchronies inducing inappropriate efforts may be involved in the development or persistence of diaphragmatic dysfunction [ 46 ], even if it is possible that the asynchronies are the result of the said dysfunction [ 47 ]. Two asynchronies can lead to excessive ventilation with the risk of dynamic hyperinflation that can alter the structure of the diaphragm; these are auto-triggers and double triggers [ 48 ].…”

Reply to Wennen et al.: Interpretation of Diaphragmatic Force Measurements in Reverse Triggering in a Porcine Model

“…We thank Dr. Wennen and colleagues for their interest in reading our study and their insightful comments on our findings ( 1 ). We agree with the authors that understanding the effects of reverse triggering (RT) on diaphragm function is important for future studies and that careful interpretation is needed.…”

Interpretation of Diaphragmatic Force Measurements in Reverse Triggering in a Porcine Model

“…We read with great interest the article by Damiani and colleagues describing an experimental model to investigate the impact of reverse triggering (RT) on diaphragm function and structure ( 1 ). We recognize the complexity of developing this model and are confident that it will be important for future studies.…”

“…In Figure 5 of their work ( 1 ), in part A, diaphragm pressure (Pdi) after a single twitch stimulus (Pdi,twitch) after 1, 2, and 3 hours, and in part B, the Pdi force–frequency (F/F) relationship after 3 hours of mechanical ventilation, are reported, with values normalized to measurements at baseline. The Pdi,twitch ratio was approximately 1.15, 0.93, 0.66, and 0.85 after 3 hours for the RT low effort, RT middle effort, RT high effort, and passive group, respectively (Figure 5A).…”

“…Last, animals were divided into groups based on the tertiles of measured levels of breathing effort and not by defining limits for effort a priori . It is suggested that a certain level of breathing effort can be protective for the diaphragm; however, it appears that some subjects in the RT middle-effort and RT low-effort groups have very similar levels of breathing effort (Figure 3 of the original work [ 1 ]). We therefore suggest that the emphasis on group-related outcomes should be attenuated.…”