Effects of nasal continuous positive airway pressure (NCPAP) on breathing pattern in spontaneously breathing premature newborn infants

Objective: The aim of the study was to assess the influence of nasal continuous positive airway pressure (NCPAP) on breathing pattern in preterm newborns. Design: Prospective study. Setting: Neonatal intensive care unit. Patients: Ten premature newborn infants on NCPAP (gestational age range from 27 to 32 weeks, mean birth weight 1300 +/- 460 g) admitted in our neonatal intensive care unit (NICU) for respiratory distress syndrome. Methods: Breathing patterns and changes in lung volumes level were obtained using respiratory inductive plethysmography (RIP), at random CPAP levels (0, 2,4,6 and 8 cmH(2)O). Raw data were analysed for end-expiratory lung volume level (EELV-level), tidal volume (Vt), respiratory rate, phase angle and tabour breathing index (LBI). Results: CPAP increased EELV-level by 2.1 +/- 0.3xVt from 0 to 8 cmH(2)O (p < 0.01). Vt increased by 43 % from CPAP of 0 cmH(2)O to CPAP of 8 cmH(2)O (P < 0.01). We also found that CPAP lowered the phase angle (from 76 +/- 21 degrees at CPAP of 0 cm H2O to 30 +/- 15 at CPAP of 8 cmH(2)O; p < 0.01) and LBI (from 1.7 0.8 at CPAP of 0 cmH(2)O to 1.2 +/- 0.3 at CPAP of 8 cmH(2)O; P < 0.05). Conclusion: NCPAP improves the breathing strategy of premature infants with respiratory failure, as reflected by improved thoraco-abdominal synchrony, increased Vt and reduction of the LBI. This effect is associated with an increase in EELV-level with CPAP level. However, further investigations are necessary to establish the best CPAP level that ensures both safety and efficiency.