title: Changes in lung volume and work of breathing: A comparison of two variable-flow nasal continuous positive airway pressure devices in very low birth weight infants.
abstract: Variable flow nasal continuous positive airway pressure (VF-NCPAP) recruits lung volume more effectively and reduces work of breathing (WOB) compared to constant-flow NCPAP (CF-NCPAP) in very low birth weight (VLBW) infants. Because different VF-NCPAP devices have somewhat different flow patterns, whether different VF-NCPAP devices function similarly is unknown. We compared two VF-NCPAP devices: the Infant Flow trade mark (EME, Ltd.) and the Arabella(R) (Hamilton Medical) to assess whether lung volume recruitment and WOB were similar in VLBW infants requiring NCPAP. Eighteen infants <1,500 g were studied on both NCPAP devices applied in random order. All infants required NCPAP for mild respiratory distress. Calibrated DC-coupled respiratory inductance plethysmography (RIP) was used to assess lung volume changes. NCPAP was first increased to 8 cmH(2)O to allow comparable recruitment in all infants, and then was slowly decreased to 6, 4, and 0 cmH(2)O, with data collection at each level. Mean birth weight (+/-SD) was 1,107 +/- 218 g, gestational age was 27.9 +/- 2.0 weeks, weight at study was 1,092 +/- 222 g, and age at study was 4.6 +/- 4.3 days. There were no differences in lung volume recruitment overall or at any NCPAP level (P = 0.943). No differences were found in either inspiratory WOB (P = 0.468) or in resistive WOB (P = 0.610) between devices. Compliance, tidal volume, respiratory rate, and minute ventilation were also similar. Despite differences in flow characteristics between the two VF-NCPAP devices we studied, lung volume recruitment and WOB were similar.
authors.affiliation: Robert Wood Johnson Medical School, Div. of Neonatology, Dep. of Pediatrics, Children's Regional Hospital at Cooper Hospital/Univ. Medical Center, Camden, New Jersey, USA. scourtne@lij.edu
authors.forename: Sherry E
authors.initials: SE
authors.lastname: Courtney
authors.forename: Zubair H
authors.initials: ZH
authors.lastname: Aghai
authors.forename: Judy G
authors.initials: JG
authors.lastname: Saslow
authors.forename: Kee H
authors.initials: KH
authors.lastname: Pyon
authors.forename: Robert H
authors.initials: RH
authors.lastname: Habib
mesh_terms: D001724:Birth Weight; D045422:Continuous Positive Airway Pressure / Q000295:instrumentation*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D019102:Infant, Very Low Birth Weight; D008176:Lung Volume Measurements / Q000295:instrumentation; D008297:Male; D012016:Reference Values; D012129:Respiratory Function Tests / Q000295:instrumentation; D012680:Sensitivity and Specificity; D014939:Work of Breathing