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Extubation generates lung volume inhomogeneity in preterm infants


Objective To evaluate the feasibility of electrical impedance tomography (EIT) to describe the regional tidal ventilation (VT) and change in end-expiratory lung volume (EELV) patterns in preterm infants during the process of extubation from invasive to non-invasive respiratory support.

Design Prospective observational study.

Setting Single-centre tertiary neonatal intensive care unit.

Patients Preterm infants born <32 weeks’ gestation who were being extubated to nasal continuous positive airway pressure as per clinician discretion.

Interventions EIT measurements were taken in supine infants during elective extubation from synchronised positive pressure ventilation (SIPPV) before extubation, during and then at 2 and 20 min after commencing nasal continuous positive applied pressure (nCPAP). Extubation and pressure settings were determined by clinicians.

Main outcome measures Global and regional ΔEELV and ΔVT, heart rate, respiratory rate and oxygen saturation were measured throughout.

Results Thirty infants of median (range) 2 (1, 21) days were extubated to a median (range) CPAP 7 (6, 8) cm H2O. SpO2/FiO2 ratio was a mean (95% CI) 50 (35, 65) lower 20 min after nCPAP compared with SIPPV. EELV was lower at all points after extubation compared with SIPPV, and EELV loss was primarily in the ventral lung (p=0.04). VT was increased immediately after extubation, especially in the central and ventral regions of the lung, but the application of nCPAP returned VT to pre-extubation patterns.

Conclusions EIT was able to describe the complex lung conditions occurring during extubation to nCPAP, specifically lung volume loss and greater use of the dorsal lung. EIT may have a role in guiding peri-extubation respiratory support.

  • neonatology
  • technology

Data availability statement

Data are available on reasonable request. Deidentified individual participant data, study protocols and statistical analysis codes are available from 3 months to 23 years following article publication to researchers who provide a methodologically sound proposal, with approval by an independent review committee ('learned intermediary'). Proposals should be directed to to gain access. Data requestors will need to sign a data access or material transfer agreement approved by MCRI.

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