Dyssynchronous diaphragm contractions impair diaphragm function in mechanically ventilated patients.

Area of Science:

• Critical Care Medicine
• Respiratory Physiology
• Mechanical Ventilation

Background:

• Pre-clinical research indicates that asynchronous diaphragm activity during mechanical ventilation may lead to acute diaphragm dysfunction.
• Understanding diaphragm contractile loading variability is crucial for preventing ventilator-induced diaphragm injury.

Purpose of the Study:

• To quantify the variability of diaphragm contractile loading during mechanical ventilation.
• To determine if asynchronous diaphragm contractions correlate with the development of diaphragm dysfunction.

Main Methods:

• Hourly recordings of airway flow, pressure, and diaphragm electrical activity (Edi) were collected from 45 patients on invasive mechanical ventilation for up to 7 days.
• Dyssynchronous post-inspiratory diaphragm loading was identified based on neural inspiration duration post-ventilator cycling.
• Diaphragm function was assessed daily using neuromuscular coupling (NMC).

Main Results:

• Over 4500 hours of data revealed low or absent Edi in 51% of hours.
• Dyssynchronous post-inspiratory loading occurred in 13% of hours, significantly associated with reverse triggering and premature cycling.
• The duration and intensity of dyssynchronous loading correlated with a progressive decrease in diaphragm NMC.

Conclusions:

• Asynchronous diaphragm contractions during mechanical ventilation can negatively impact diaphragm function.
• Ventilator settings that promote dyssynchronous loading contribute to diaphragm dysfunction over time.