RT Journal Article SR Electronic T1 Effects of non-synchronised nasal intermittent positive pressure ventilation on spontaneous breathing in preterm infants JF Archives of Disease in Childhood - Fetal and Neonatal Edition JO Arch Dis Child Fetal Neonatal Ed FD BMJ Publishing Group Ltd and Royal College of Paediatrics and Child Health SP F422 OP F428 DO 10.1136/adc.2010.205195 VO 96 IS 6 A1 Owen, L S A1 Morley, C J A1 Dawson, J A A1 Davis, P G YR 2011 UL http://fn.bmj.com/content/96/6/F422.abstract AB Background Nasal intermittent positive pressure ventilation (NIPPV) may be beneficial but the mechanisms of action are undetermined. Aim To investigate the effects of non-synchronised NIPPV on spontaneous breathing in premature infants. Methods 10 infants receiving ventilator generated non-synchronised NIPPV were studied for 30 min. Delivered pressure was measured at the nose; respiration was recorded using respiratory inductance plethysmography. Oxygen saturation, carbon dioxide, heart rate, inspired oxygen and video images were recorded. Results Median gestational age, birth weight, age and study weight were 25+3 weeks, 797 g, 24 days and 1076 g. When the NIPPV pressure peak commenced during spontaneous inspiration the inspiratory time increased by 21% (p=0.002), relative tidal volume increased by 15% (p=0.01) and expiratory time was unchanged. When the NIPPV pressure peak commenced during spontaneous expiration the expiratory time increased by 13% (p=0.04). NIPPV pressures delivered during apnoea (range 8–28 cm H2O) produced chest inflation 5% of the time, resulting in small tidal volumes (26.7% of spontaneous breath size) but reduced oxygen desaturation. NIPPV pressure peaks occurred throughout spontaneous respiration proportional to the inspiratory: expiratory ratio. Conclusion NIPPV pressure peaks only resulted in a small increase in relative tidal volumes when delivered during spontaneous inspiration. During apnoea pressure peaks occasionally resulted in chest inflation, which ameliorated oxygen desaturations. Infants did not become entrained with the NIPPV pressure changes. Synchronising every rise in applied pressure with spontaneous inspiration may increase the effectiveness of NIPPV and warrants investigation.