Changes in lung volume and work of breathing: A comparison of two variable-flow nasal continuous positive airway pressure devices in very low birth weight infants

Pediatr Pulmonol. 2003 Sep;36(3):248-52. doi: 10.1002/ppul.10327.


Variable flow nasal continuous positive airway pressure (VF-NCPAP) recruits lung volume more effectively and reduces work of breathing (WOB) compared to constant-flow NCPAP (CF-NCPAP) in very low birth weight (VLBW) infants. Because different VF-NCPAP devices have somewhat different flow patterns, whether different VF-NCPAP devices function similarly is unknown. We compared two VF-NCPAP devices: the Infant Flow trade mark (EME, Ltd.) and the Arabella(R) (Hamilton Medical) to assess whether lung volume recruitment and WOB were similar in VLBW infants requiring NCPAP. Eighteen infants <1,500 g were studied on both NCPAP devices applied in random order. All infants required NCPAP for mild respiratory distress. Calibrated DC-coupled respiratory inductance plethysmography (RIP) was used to assess lung volume changes. NCPAP was first increased to 8 cmH(2)O to allow comparable recruitment in all infants, and then was slowly decreased to 6, 4, and 0 cmH(2)O, with data collection at each level. Mean birth weight (+/-SD) was 1,107 +/- 218 g, gestational age was 27.9 +/- 2.0 weeks, weight at study was 1,092 +/- 222 g, and age at study was 4.6 +/- 4.3 days. There were no differences in lung volume recruitment overall or at any NCPAP level (P = 0.943). No differences were found in either inspiratory WOB (P = 0.468) or in resistive WOB (P = 0.610) between devices. Compliance, tidal volume, respiratory rate, and minute ventilation were also similar. Despite differences in flow characteristics between the two VF-NCPAP devices we studied, lung volume recruitment and WOB were similar.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Birth Weight
  • Continuous Positive Airway Pressure / instrumentation*
  • Female
  • Humans
  • Infant, Newborn
  • Infant, Very Low Birth Weight*
  • Lung Volume Measurements / instrumentation
  • Male
  • Reference Values
  • Respiratory Function Tests / instrumentation
  • Sensitivity and Specificity
  • Work of Breathing*