Influence of ventilatory settings on pendelluft and expiratory muscle activity in hypoxemic patients resuming spontaneous breathing.

Summary

In a randomized crossover physiological study of hypoxemic ARDS patients transitioning to spontaneous breathing, higher pressure support reduced pendelluft and expiratory muscle activity. Higher PEEP decreased pendelluft but could be offset by increased expiratory muscle activity, underscoring the need to balance PS and PEEP during weaning.

Key Findings

• Randomized crossover testing of PSV 5/10/15 cmH2O showed higher PS reduced pendelluft and expiratory muscle activity.
• Higher PEEP decreased pendelluft, but its benefit could be offset by increased expiratory muscle activity.
• Electrical impedance tomography guided PEEP selection and characterization of pendelluft dynamics.

Clinical Implications

When resuming spontaneous breathing in ARDS, consider higher pressure support to reduce pendelluft and expiratory loading; use PEEP to curb pendelluft but monitor for increased expiratory muscle activity.

Limitations

• Small sample size (n=15) and short-term physiological endpoints
• Abstract lacks detailed statistical metrics and comprehensive results reporting

Future Directions

Larger multicenter trials to test whether PS/PEEP strategies that minimize pendelluft improve clinical outcomes; integrate esophageal manometry and diaphragm ultrasound for comprehensive load monitoring.