No association between thickening fraction of the diaphragm and extubation success in ventilated children

Anita Duyndam; Joke Smit; Robert Jan Houmes; Leo Heunks; Jeroen Molinger; Marloes IJland; Joost van Rosmalen; Monique van Dijk; Dick Tibboel; Erwin Ista

doi:10.3389/fped.2023.1147309

No association between thickening fraction of the diaphragm and extubation success in ventilated children

Front Pediatr. 2023 Mar 24:11:1147309. doi: 10.3389/fped.2023.1147309. eCollection 2023.

Authors

Anita Duyndam¹, Joke Smit¹, Robert Jan Houmes¹, Leo Heunks², Jeroen Molinger^{2

3}, Marloes IJland⁴, Joost van Rosmalen^{5

6}, Monique van Dijk^{1

2}, Dick Tibboel^{1

2}, Erwin Ista¹

Affiliations

¹ Pediatric Intensive Care, Department of Pediatric Surgery, Erasmus MC-Sophia Children's Hospital, University Medical Center Rotterdam, Rotterdam, Netherlands.
² Intensive Care Adults, Erasmus MC, University Medical Center Rotterdam, Rotterdam, Netherlands.
³ Division of Critical Care, Department of Anesthesiology, Duke University School of Medicine, Durham, NC, United States.
⁴ Department of Intensive Care Medicine, Radboud University Medical Center, Radboud Institute for Health Sciences, Nijmegen, Netherlands.
⁵ Department of Biostatistics, Erasmus MC, University Medical Center Rotterdam, Rotterdam, Netherlands.
⁶ Department of Epidemiology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, Netherlands.

Abstract

Introduction: 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.

Aim: 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.

Method: 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).

Results: 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); p = 0.045. At baseline, pre-extubation and post-extubation there was no significant correlation between age and BSA on the one hand and dTF, Tdi- insp and Tdi-exp on the other hand. The ICC representing the level of inter-rater reliability between the two examiners performing the ultrasounds was 0.994 (95% CI 0.970-0.999). The ICC of the inter-rater reliability between the raters in 36 paired assessments was 0.983 (95% CI 0.974-0.990).

Conclusion: There was no significant association between thickening fraction of the diaphragm and extubation success in ventilated children.

Keywords: diaphragm; mechanical ventilation; pediatric; thickening fraction; ultrasound.