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.
Keywords: neonatology; technology.
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