Evaluating Clinically Directed Continuous Positive Airway Pressure to High Flow Nasal Cannula Transitions in Stable Preterm Infants Using Electrical Impedance Tomography: A Prospective, Observational Study.

OBJECTIVE

To assess lung aeration changes during clinically directed transitions from CPAP to HFNC in preterm infants using Electrical Impedance Tomography (EIT).

DESIGN

Prospective, observational study.

SETTING

Single-center, Level IV Neonatal Intensive Care Unit.

PATIENTS: Infants born < 32 weeks gestational age (GA) undergoing a clinically indicated transition from CPAP to HFNC following ≥ 2 weeks of respiratory support.

INTERVENTIONS: EIT data were recorded for 30-60 min before and after transition.

MAIN OUTCOME MEASURES: The primary outcome was change in end-expiratory lung impedance (ΔEELI). Infants were followed for 7 days following transition to assess for transition failure.

RESULTS

From 15 subjects, 4257 total breaths were analyzed. No significant difference in %∆EELI was found between HFNC and CPAP (Median ∆: -1.0%; IQR -3.6% to 6.0%; p = 0.78). The largest %∆EELI decrease (-9.8%) occurred in the subject who failed transition.

CONCLUSIONS

Transitioning from CPAP to HFNC did not consistently decrease lung aeration in stable preterm infants. In the infant who failed transition, a distinct respiratory pattern was observed using EIT, characterized by a decrease in EELI and frequent recruitment breaths. These findings suggest better methods are needed to individualize and titrate respiratory support at the bedside for preterm infants.