Thoracoabdominal motion in newborns during ventilation delivered by endotracheal tube or nasal prongs.

Preterm infants have asynchronous thoracoabdominal motion (TAM) secondary to a highly compliant chest wall and different lung mechanics compared to term infants. We compared TAM during continuous positive airway pressure (CPAP) administered through an endotracheal tube (ETT-CPAP) or nasal prongs (nasal-CPAP), and during synchronized intermittent mandatory ventilation administered by nasal prongs (nasal-SIMV) in 14 preterm newborn infants. Asynchrony of TAM was quantified by measuring relative motion of chest wall and abdomen with strain gauges and calculating phase angles (theta). Phase angles were lower during nasal-SIMV compared to nasal-CPAP or ETT-CPAP (P < 0.05), and lower during nasal-CPAP compared to ETT-CPAP (P < 0.05). The reduced TAM asynchrony during nasal-SIMV and nasal-CPAP may be due to elimination of resistance of the ETT and/or effective stabilization of the chest wall. These data suggest that nasal-SIMV may be an effective mode of respiratory support for preterm infants requiring minimal ventilatory support.