Diaphragm Thickening Fraction Fails to Predict Esophageal Pressure or Ventilator Weaning in Children.

Abstract

Studies relating diaphragm thickening fraction (DTF), delta esophageal pressure (dPes), and weaning outcomes are lacking in critically ill children. How well does DTF correlate with dPes and predict weaning/extubation outcomes? Secondary analysis of children with ARDS from a single-center randomized control trial. DTF and dPes were measured daily during mechanical ventilation and during spontaneous breathing trials (SBT, CPAP 5 cmH₂O). SBT outcomes were classified as Early Failure (SBT failure within 30 minutes), Late Failure (SBT failure between 30 to 120 minutes) and SBT success. Extubation outcomes were classified as Prolonged Non-Invasive Ventilation (NIV > 72 hours), Reintubation within 48 hours, and Successful Extubation. There were 194 patients with 704 Daily measurements. The correlation between the Daily DTF and dPes was r = 0.10 (95% CI = 0.01-0.19). There were 171 successful SBTs, 60 early failures, and 88 late failures, with no difference in the median SBT DTF between groups (Early Failure: 20% (10, 32), Late Failure: 18% (12, 26), Success: 19% (11, 28), P = 0.69). The SBT DTF was not predictive of extubation success or failure (reintubation or prolonged NIV) (AUC = 0.54, 95% CI = 0.44-0.64), with the median SBT DTF of 19% (IQR = 11-31, n = 124) for those successfully extubated; 23% (IQR = 16-30, n = 12) for those reintubated; and 17% (IQR = 10-23, n = 30) for those who received prolonged NIV (P = 0.3). DTF should be used with caution in children as it does not appear to have a strong correlation with measures of respiratory effort and does not reliably predict SBT or extubation outcomes.