In mechanically ventilated adults, thickening fraction of diaphragm (dTF) measured by ultrasound is used to predict extubation success. Whether dTF can also predict extubation success in children is unclear.
To investigate the association between dTF and extubation success in children. Second, to assess diaphragm thickness during ventilation and the correlation between dTF, diaphragm thickness (Tdi), age and body surface.
Prospective observational cohort study in children aged 0–18 years old with expected invasive ventilation for >48 h. Ultrasound was performed on day 1 after intubation (baseline), day 4, day 7, day 10, at pre-extubation, and within 24 h after extubation. Primary outcome was the association between dTF pre-extubation and extubation success. Secondary outcome measures were Tdi end-inspiratory and Tdi end-expiratory and atrophy defined as <10% decrease of Tdi end-expiratory versus baseline at pre-extubation. Correlations were calculated with Spearman correlation coefficients. Inter-rater reliability was calculated with intraclass correlation (ICC).
Fifty-three patients, with median age 3.0 months (IQR 0.1–66.0) and median duration of invasive ventilation of 114.0 h (IQR 55.5–193.5), were enrolled. Median dTF before extubation with Pressure Support 10 above 5 cmH2O was 15.2% (IQR 9.7–19.3). Extubation failure occurred in six children, three of whom were re-intubated and three then received non-invasive ventilation. There was no significant association between dTF and extubation success; OR 0.33 (95% CI; 0.06–1.86). Diaphragmatic atrophy was observed in 17/53 cases, in three of extubation failure occurred. Children in the extubation failure group were younger: 2.0 months (IQR 0.81–183.0) vs. 3.0 months (IQR 0.10–48.0);
There was no significant association between thickening fraction of the diaphragm and extubation success in ventilated children.