title: Comparative evaluation of three interfaces for non-invasive ventilation: a randomized cross-over design physiologic study on healthy volunteers.
abstract: BACKGROUND
  Interface choice is crucial for non-invasive ventilation (NIV) success. We compared a new interface, the helmet next (HN), with the facial mask (FM) and the standard helmet (HS) in twelve healthy volunteers.
  
  
  METHODS
  In this study, five NIV trials were randomly applied, preceded and followed by a trial of unassisted spontaneous breathing (SB). Baseline settings, for example, 5 cmH2O of both inspiratory pressure support (PS) and positive end-expiratory pressure (PEEP), were applied through FM, HS and HN, while increased settings (PS and PEEP of 8 cmH2O) were only applied through HS and HN. We measured flow, airway, esophageal and gastric pressures, and calculated inspiratory effort indexes and trigger delays. Comfort was assessed with a visual-analog-scale.
  
  
  RESULTS
  We found that FM, HS and HN at baseline settings were not significantly different with respect to inspiratory effort indexes and comfort. Inspiratory trigger delay and time of synchrony (TI,synchrony) were significantly improved by FM compared to both helmets, whereas expiratory trigger delay was shorter with FM, as opposed to HS only. HN at increased settings performed better than FM in decreasing inspiratory effort measured by pressure-time product of transdiaphragmatic pressure (PTPdi)/breath (10.7 ± 9.9 versus 17.0 ± 11.0 cmH2Os), and PTPdi/min (128 ± 96 versus 204 ± 81 cmH2Os/min), and PTPdi/L (12.6 ± 9.9 versus 30.2 ± 16.8 cmH2Os/L). TI, synchrony was inferior between HN and HS at increased settings and FM.
  
  
  CONCLUSIONS
  HN might hold some advantages with respect to interaction and synchrony between subject and ventilator, but studies on patients are needed to confirm these findings.
  
  
  BACKGROUND
  ClinicalTrials.gov NCT01610960.
authors.forename: Rosanna
authors.initials: R
authors.lastname: Vaschetto
authors.forename: Audrey
authors.initials: A
authors.lastname: De Jong
authors.forename: Matthieu
authors.initials: M
authors.lastname: Conseil
authors.forename: Fabrice
authors.initials: F
authors.lastname: Galia
authors.forename: Martin
authors.initials: M
authors.lastname: Mahul
authors.forename: Yannael
authors.initials: Y
authors.lastname: Coisel
authors.forename: Albert
authors.initials: A
authors.lastname: Prades
authors.forename: Paolo
authors.initials: P
authors.lastname: Navalesi
authors.forename: Samir
authors.initials: S
authors.lastname: Jaber
mesh_terms: D000328:Adult; D018592:Cross-Over Studies; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007385:Intermittent Positive-Pressure Ventilation / Q000295:instrumentation / Q000379:methods / Q000592:standards*; D008297:Male; D063087:Noninvasive Ventilation / Q000295:instrumentation / Q000379:methods / Q000592:standards*; D011175:Positive-Pressure Respiration / Q000295:instrumentation / Q000379:methods / Q000592:standards*; D012123:Pulmonary Ventilation / Q000502:physiology; D055815:Young Adult