title: Tidal breathing in preterm infants receiving and weaning from continuous positive airway pressure.
abstract: OBJECTIVE
  To compare tidal breathing on different continuous positive airway pressure (CPAP) devices and pressures and to serially measure tidal breathing during weaning off CPAP using electromagnetic inductive plethysmography.
  
  
  METHODS
  Using electromagnetic inductive plethysmography, tidal breathing was measured in 29 preterm infants receiving CPAP, gestational age 28 ± 2 weeks. Variable-flow nasal CPAP (nCPAP), bubble CPAP (bCPAP) at pressures of 5, 7, and 9 cmH2O, nasal bi-level positive airway pressure (nBiPAP) system at pressures of 5, 7/5, and 9/5 cmH2O, and unsupported breathing were studied. Twenty-one infants had weekly tidal breathing measurements on and off nCPAP.
  
  
  RESULTS
  Minute volume (MV/kg) was similar between all devices (0.30-0.33 L/kg/min). On bCPAP, weight corrected tidal volume (VT/kg) was the least, changing little with increasing pressures. On nCPAP and nBiPAP, VT/kg increased with increasing pressure and the respiratory rate (fR) decreased. The delivered pressure varied slightly from the set pressure being most dissimilar on nBiPAP and similar on bCPAP. Compared with unsupported breathing, all devices decreased VT/kg, MV/kg, and phase angle, but did not alter fR. Serial tidal breathing measurements showed decreasing difference for VT/kg over time on and off nCPAP.
  
  
  CONCLUSIONS
  At different pressure settings, on all CPAP devices the measured MV/kg was similar either through increasing VT/kg and decreasing fR (nCPAP and nBiPAP) or maintaining both (bCPAP). Serial tidal breathing measurements may aid weaning from CPAP.
authors: Department of Child Health, Cardiff University, Cardiff, United Kingdom.
authors: Nicole
authors: N
authors: Pickerd
authors: Faculty of Life Sciences and Education, University of South Wales, Pontypridd, United Kingdom.
authors: Edgar Mark
authors: EM
authors: Williams
authors: Department of Child Health, Cardiff University, Cardiff, United Kingdom.
authors: William John
authors: WJ
authors: Watkins
authors: Department of Child Health, Cardiff University, Cardiff, United Kingdom. Electronic address: KotechaS@cardiff.ac.uk.
authors: Sailesh
authors: S
authors: Kotecha
mesh_terms: D045422:Continuous Positive Airway Pressure / Q000295:instrumentation / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology*; D008297:Male; D017063:Outcome Assessment, Health Care; D010991:Plethysmography; D011312:Pressure; D015656:Respiratory Mechanics / Q000502:physiology*; D013990:Tidal Volume; D015300:Ventilator Weaning