Predictors of Negative Pressure Ventilation Response in Pediatric Acute Respiratory Failure

Background: Use of negative pressure ventilation is neither well described nor widespread in pediatric critical care; existing data are from small, specialized populations. We sought to describe a general population of critically ill subjects with acute respiratory failure supported with negative pressure ventilation to find predictors of response or failure.

Methods: We conducted a retrospective cohort study of subjects 0-18 y old admitted to a single (non-cardiac) pediatric ICU who received acute respiratory failure support via negative pressure ventilation from May 2015 through May 2016.

Results: In 118 subjects, the most common causes of acute respiratory failure were viral bronchiolitis (86.4%) and pneumonia (15.3%). A majority of subjects (68.6%) stabilized with negative pressure ventilation and did not need a change of respiratory support; in those who failed with negative pressure ventilation, median time to respiratory support change was 5.1 h (interquartile range 1.9-11.0). Subjects stabilized with negative pressure ventilation did not differ from those needing a change of respiratory support in terms of age, comorbidities, or F_IO2 at initiation of ventilation. Compared to those who did not respond to negative pressure ventilation, mean S_pO2 /F_IO2 was higher at 1 h after start of negative pressure ventilation (218.8 vs 131.7) in those who did respond. Subjects with S_pO2 /F_IO2 < 192 after 1 h on negative pressure ventilation support had 5-fold higher odds of needing a respiratory support change (odds ratio 5.143, 95% CI 1.17-22.7, P = .031). Analysis of S_pO2 /F_IO2 was limited by 81.3% (96/118) of subjects who had an S_pO2 > 97% at 1 h after the start of negative pressure ventilation.

Conclusions: Negative pressure ventilation successfully supported 69% of pediatric subjects with all-cause acute respiratory failure. Oxygen requirement was lower in subjects who were responsive to negative pressure ventilation within 1 h of initiation. Standardized negative pressure ventilation protocols should include weaning of supplemental oxygen to determine responsiveness.