Effect of sustained inflation length on establishing functional residual capacity at birth in ventilated premature rabbits

Pediatr Res. 2009 Sep;66(3):295-300. doi: 10.1203/PDR.0b013e3181b1bca4.


The effect of inflation length on lung aeration pattern, tidal volumes, and functional residual capacity (FRC) immediately after birth was investigated. Preterm rabbits (28 d), randomized into four groups, received a 1-, 5-, 10-, or 20-s inflation (SI) followed by ventilation with 5 cm H2O end-expiratory pressure. Gas volumes were measured by plethysmography and uniformity of lung aeration by phase contrast x-ray imaging for 7 min. The first inspiratory volume significantly (p < 0.001) increased with inflation duration from a median (IQR) of 0.2 (0.1-3.1) mL/kg for 1-s inflation to 23.4 (19.3-30.4) mL/kg for 20-s SI. The lung was uniformly aerated, and the FRC and tidal volume fully recruited after 20-s SI. A 10-s SI caused a higher FRC (p < 0.05) at 7 min, and a 20-s SI caused a higher FRC (p < 0.05) at 20 s and 7 min than a 1- or 5-s SI. The mean (SD) time for 90% of the lung to aerate was 14.0 (4.1) s using 35 cm H2O peak inflation pressure. In these rabbits, 10- and 20-s SI increased the inspiratory volume and produced a greater FRC, and a 20-s SI uniformly aerated the lung before ventilation started.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Newborn / anatomy & histology
  • Animals, Newborn / physiology*
  • Functional Residual Capacity / physiology*
  • Humans
  • Inhalation / physiology*
  • Insufflation
  • Lung / diagnostic imaging
  • Lung / physiology
  • Lung Volume Measurements
  • Plethysmography
  • Premature Birth
  • Rabbits
  • Radiography
  • Random Allocation
  • Respiration, Artificial / adverse effects
  • Respiration, Artificial / methods*
  • Respiratory Mechanics
  • Tidal Volume