title: Work of breathing using different interfaces in spontaneous positive pressure ventilation: helmet, face-mask, and endotracheal tube.
abstract: Noninvasive positive pressure ventilation (NPPV) using a helmet is expected to cause inspiratory trigger delay due to the large collapsible and compliant chamber. We compared the work of breathing (WOB) of NPPV using a helmet or a full face-mask with that of invasive ventilation by tracheal intubation.
  
  
  
  We used a lung model capable of simulating spontaneous breathing (LUNGOO; Air Water Inc., Japan). LUNGOO was set at compliance (C) = 50 mL/cmH2O and resistance (R) = 5 cmH2O/L/s for normal lung simulation, C = 20 mL/cmH2O and R = 5 cmH2O/L/s for restrictive lung, and C = 50 mL/cmH2O and R = 20 cmH2O/L/s for obstructive lung. Muscle pressure was fixed at 25 cmH2O and respiratory rate at 20 bpm. Pressure support ventilation and continuous positive airway pressure were performed with each interface placed on a dummy head made of reinforced plastic that was connected to LUNGOO. We tested the inspiratory WOB difference between the interfaces with various combinations of ventilator settings (positive end-expiratory pressure 5 cmH2O; pressure support 0, 5, and 10 cmH2O).
  
  
  
  In the normal lung and restrictive lung models, WOB decreased more with the face-mask than the helmet, especially when accompanied by the level of pressure support. In the obstructive lung model, WOB with the helmet decreased compared with the other two interfaces. In the mixed lung model, there were no significant differences in WOB between the three interfaces.
  
  
  
  NPPV using a helmet is more effective than the other interfaces for WOB in obstructive lung disease.
authors.affiliation: Department of Anesthesiology, Yamagata University Faculty of Medicine, 2-2-2 Iida Nishi, Yamagata, Yamagata, 990-9585, Japan. soda-ygt@umin.ac.jp.
authors.forename: Shinya
authors.initials: S
authors.lastname: Oda
authors.affiliation: Department of Anesthesiology, Yamagata University Faculty of Medicine, 2-2-2 Iida Nishi, Yamagata, Yamagata, 990-9585, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Otaki
authors.affiliation: Department of Anesthesiology, Yamagata University Faculty of Medicine, 2-2-2 Iida Nishi, Yamagata, Yamagata, 990-9585, Japan.
authors.forename: Nozomi
authors.initials: N
authors.lastname: Yashima
authors.affiliation: Department of Anesthesiology, Yamagata University Faculty of Medicine, 2-2-2 Iida Nishi, Yamagata, Yamagata, 990-9585, Japan.
authors.forename: Misato
authors.initials: M
authors.lastname: Kurota
authors.affiliation: Department of Anesthesiology, Yamagata University Faculty of Medicine, 2-2-2 Iida Nishi, Yamagata, Yamagata, 990-9585, Japan.
authors.forename: Sachiko
authors.initials: S
authors.lastname: Matsushita
authors.affiliation: Department of Anesthesiology, Yamagata University Faculty of Medicine, 2-2-2 Iida Nishi, Yamagata, Yamagata, 990-9585, Japan.
authors.forename: Airi
authors.initials: A
authors.lastname: Kumasaka
authors.affiliation: Department of Anesthesiology, Yamagata University Faculty of Medicine, 2-2-2 Iida Nishi, Yamagata, Yamagata, 990-9585, Japan.
authors.forename: Hutaba
authors.initials: H
authors.lastname: Kurihara
authors.affiliation: Department of Anesthesiology, Yamagata University Faculty of Medicine, 2-2-2 Iida Nishi, Yamagata, Yamagata, 990-9585, Japan.
authors.forename: Kaneyuki
authors.initials: K
authors.lastname: Kawamae
mesh_terms: D006260:Head Protective Devices; D006801:Humans; D007442:Intubation, Intratracheal; D008168:Lung / Q000502:physiology; D008397:Masks; D011175:Positive-Pressure Respiration; D011312:Pressure; D012119:Respiration; D012122:Ventilators, Mechanical; D014939:Work of Breathing
keywords: Helmet; Lung simulator; NPPV interface; Noninvasive positive pressure ventilation; Work of breathing