Evolution of inspiratory muscle function in children during mechanical ventilation

Area of Science:

• Pediatric critical care medicine
• Respiratory physiology
• Mechanical ventilation

Background:

• No standardized method exists to evaluate inspiratory muscle pressure-generating capacity in pediatric patients on mechanical ventilation (MV).
• Limited research has explored the temporal changes in inspiratory muscle function in this vulnerable population.

Purpose of the Study:

• To assess inspiratory muscle function in children undergoing various modes of MV.
• To describe the evolution of inspiratory muscle function over time in critically ill children.
• To compare inspiratory muscle function between critically ill children and those in the operating room.

Main Methods:

• Prospective observational study involving children on MV.
• Simultaneous recording of airway pressure depression (ΔPaw) and electrical activity of the diaphragm (EAdi) during brief airway occlusions.
• Calculation of neuro-mechanical efficiency ratio (NME = ΔPaw/EAdi_max).

Main Results:

• Inspiratory muscle efficiency (NME_occl) decreased over time in critically ill children on MV (p=0.03).
• Maximum inspiratory pressure generation (ΔPaw_max) remained stable in the pediatric intensive care unit (PICU) group.
• Critically ill children (PICU) showed significantly lower NME_occl compared to children in the operating room (OR) (p=0.015).

Conclusions:

• Bedside monitoring of inspiratory muscle function in children on MV is feasible using airway occlusions.
• Critically ill children on MV exhibit reduced inspiratory muscle efficiency, which further declines during ventilation.
• Both critical illness and mechanical ventilation appear to negatively impact inspiratory muscle efficiency in children.