Work of breathing during nasal continuous positive airway pressure in preterm infants: a comparison of bubble vs variable-flow devices

J Perinatol. 2005 Jul;25(7):453-8. doi: 10.1038/


Objective: To compare work of breathing and breathing asynchrony during bubble nasal continuous positive airway pressure (NCPAP) vs variable-flow (VF)-NCPAP in premature infants.

Study design: We studied 18 premature infants of birth weight <1500 g who required NCPAP for mild respiratory distress. Each infant was studied on bubble and VF-NCPAP at 8, 6, 4, and 0 cm H2O. Tidal volumes were obtained by calibrated respiratory inductance plethysmography. Esophageal pressure estimated intrapleural pressure. Inspiratory and resistive work of breathing were calculated from pressure-volume data. Breathing asynchrony was assessed with phase angle. The results at all NCPAP levels were referenced to VF-NCPAP values at 8 cm H2O.

Results: Provision of NCPAP with either device decreased inspiratory work of breathing, tidal volume, and minute ventilation relative to NCPAP of 0 cm H2O. Bubble NCPAP did not decrease resistive work of breathing relative to 0 cm H2O. Resistive work of breathing (p=0.01), respiratory rate (p<0.03), and phase angle (p=0.002) were all greater with bubble compared to VF-NCPAP.

Conclusion: The more labored and asynchronous breathing seen with bubble NCPAP may lead to higher failure rates over the long term than with VF-NCPAP.

Publication types

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

MeSH terms

  • Continuous Positive Airway Pressure / instrumentation*
  • Cross-Over Studies
  • Humans
  • Infant, Newborn
  • Infant, Premature
  • Infant, Very Low Birth Weight
  • Lung Compliance / physiology
  • Respiratory Distress Syndrome, Newborn / physiopathology*
  • Respiratory Distress Syndrome, Newborn / therapy
  • Respiratory Mechanics / physiology
  • Tidal Volume / physiology
  • Work of Breathing / physiology*