The Effect of Extended Continuous Positive Airway Pressure on Changes in Lung Volumes in Stable Premature Infants: A Randomized Controlled Trial

Abstract

Objective: To compare changes in lung volumes, as measured by functional residual capacity (FRC), through to discharge in stable infants randomized to 2 weeks of extended continuous positive airway pressure CPAP (eCPAP) vs CPAP discontinuation (dCPAP).

Study design: Infants born at ≤32 weeks of gestation requiring ≥24 hours of CPAP were randomized to 2 weeks of eCPAP vs dCPAP when meeting CPAP stability criteria. FRC was measured with the nitrogen washout technique. Infants were stratified by gestational age (<28 and ≥ 28 weeks) and twin gestation. A linear mixed-effects model was used to evaluate the change in FRC between the 2 groups. Data were analyzed blinded to treatment group allocation.

Results: Fifty infants were randomized with 6 excluded, for a total of 44 infants. Baseline characteristics were similar in the 2 groups. The infants randomized to eCPAP vs dCPAP had a greater increase in FRC from randomization through 2 weeks (12.6 mL vs 6.4 mL; adjusted 95% CI, 0.78-13.47; P = .03) and from randomization through discharge (27.2 mL vs 17.1 mL; adjusted 95% CI, 2.61-17.59; P = .01).

Conclusions: Premature infants randomized to eCPAP had a significantly greater increase in FRC through discharge compared with those randomized to dCPAP. An increased change in FRC may lead to improved respiratory health.

Trial registration: ClinicalTrials.gov: NCT02249143.

Keywords: continuous positive airway pressure; functional residual capacity; premature.

Copyright © 2019. Published by Elsevier Inc.

Figures

Figure 1.

CONSORT diagram of randomized premature infants. Enrollment, randomization, and the study of randomized infants through discharge.

Figure 2.

FRC in randomized patients. Changes in FRC (mean ± SEM) in the eCPAP group (red) and the dCPAP group (blue) in 44 patients (22 in each group) at randomization, in 22 patients with eCPAP and 21 patients with dCPAP at the 2-week time point, and in 17 patients with eCPAP and 18 patients with dCPAP at discharge. The solid lines denote the treatment period from randomization through the 2 weeks of treatment, and the dashed lines denote the interval from the end of treatment to discharge. P = .03 for the change in FRC from randomization to the end of 2 weeks of treatment between the randomized groups; P = .01 for the change in FRC from randomization to discharge between the randomized groups. FRC values over time were modeled using linear mixed-effects regression models with repeated measures for time, treatment–time interaction, and adjusting for sex, twins, and weight at randomization.