Pediatric extubation readiness tests should not use pressure support.

Area of Science:

• Pediatric critical care medicine
• Respiratory physiology
• Mechanical ventilation

Background:

• Pressure support (PS) is commonly used to assess extubation readiness, aiming to mitigate the work of breathing (WOB) imposed by endotracheal tubes.
• The accuracy of PS and continuous positive airway pressure (CPAP) in reflecting post-extubation WOB is not well-established.

Purpose of the Study:

• To compare the effort of breathing during CPAP with post-extubation effort in intubated children.
• To investigate if endotracheal tube size or noninvasive respiratory support influences this comparison.

Main Methods:

• A prospective trial involving 409 intubated children.
• Esophageal manometry was used to measure the pressure rate product (PRP) as an index of WOB.
• PRP was compared under four conditions: PS (10/5 cmH2O), CPAP (5 cmH2O), and spontaneous breathing at 5 and 60 minutes post-extubation.
• Subgroup analyses considered upper airway obstruction (UAO), endotracheal tube size, and noninvasive respiratory support.

Main Results:

• PRP was significantly lower during PS (100 IQR 60-175) compared to CPAP (200 IQR 120-300), 5-minute post-extubation (300 IQR 150-500), and 60-minute post-extubation (255 IQR 175-400).
• Even after excluding patients with UAO, PS underestimated post-extubation effort by 126-147%, and CPAP by 17-25%.
• These findings held true across different endotracheal tube sizes and in patients receiving noninvasive respiratory support post-extubation.

Conclusions:

• Pressure support ventilation significantly underestimates the actual effort of breathing required by children after extubation.
• CPAP also underestimates post-extubation effort, though to a lesser extent than PS.
• Current extubation readiness tests using PS may not accurately predict post-extubation respiratory demands.