title: A pilot study of upper airway management using a remote-controlled artificial muscle device during propofol anesthesia.
abstract: OBJECTIVE
  To test the hypothesis that the jaw closure using a pneumatic actuator device affect airway collapsibility and resistance during propofol anesthesia.
  
  
  METHODS
  Prospective, randomized study.
  
  
  METHODS
  University-affiliated hospital.
  
  
  METHODS
  Six male subjects were included in the present study.
  
  
  METHODS
  We used pressure-flow relationships to evaluate critical closing pressure (PCRIT) and upper airway resistance in different conditions of body and head position. Anesthesia was induced and maintained with a propofol infusion, targeting a constant blood concentration of 1.5 to 2.0μg/mL to establish an adequate depth of anesthesia, with patients breathing spontaneously through a nasal mask. An air-inflatable pneumatic actuator was used to achieve jaw closure. Nasal mask pressure was intermittently reduced to evaluate upper airway collapsibility (passive PCRIT) and upstream resistance under 4 different conditions: (1) neutral occlusion at 0-cm head elevation (baseline), (2) jaw closure at 0-cm head elevation, (3) neutral occlusion at 6-cm head elevation, and (4) jaw closure at 6-cm head elevation. PCRIT and upstream resistance under each condition were compared using 1-way analysis of variance. P<.05 was considered significant.
  
  
  METHODS
  The pressure and inspiratory flow at the subjects' nose mask were recorded. Polysomonographic parameters (electroencephalograms, electrooculograms, submental electromyograms, and plethysmogram) were also recorded.
  
  
  RESULTS
  The combination of 6-cm head elevation with jaw closure using the pneumatic actuator decreased upper airway collapsibility (PCRIT≈-3.0 cm H2O) compared to the baseline position (PCRIT≈-1.2 cm H2O; P=.0003).
  
  
  CONCLUSIONS
  We demonstrated that jaw closure using an air-inflatable pneumatic actuator device can produce substantial decreases in upper airway collapsibility and maintain upper airway patency during propofol anesthesia.
authors.affiliation: Department of Dental Anesthesiology, Nagasaki University Hospital, Nagasaki, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Kurata
authors.affiliation: Department of Clinical Physiology, Nagasaki University Graduate School of Biomedical Science, Nagasaki, Japan.
authors.forename: Takurou
authors.initials: T
authors.lastname: Sanuki
authors.affiliation: Department of Clinical Physiology, Nagasaki University Graduate School of Biomedical Science, Nagasaki, Japan.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Okayasu
authors.affiliation: Department of Dental Anesthesiology, Nagasaki University Hospital, Nagasaki, Japan.
authors.forename: Mari
authors.initials: M
authors.lastname: Kawai
authors.affiliation: Department of Electrical, Electronic, and Communication Engineering, Chuo University, Tokyo, Japan.
authors.forename: Shunji
authors.initials: S
authors.lastname: Moromugi
authors.affiliation: Department of Dental Anesthesiology, Nagasaki University Hospital, Nagasaki, Japan; Department of Clinical Physiology, Nagasaki University Graduate School of Biomedical Science, Nagasaki, Japan. Electronic address: ayuse@nagasaki-u.ac.jp.
authors.forename: Takao
authors.initials: T
authors.lastname: Ayuse
mesh_terms: D000328:Adult; D058109:Airway Management / Q000379:methods*; D000402:Airway Obstruction / Q000517:prevention & control*; D000403:Airway Resistance; D000771:Anesthesia, Intravenous / Q000379:methods; D018686:Anesthetics, Intravenous / Q000008:administration & dosage*; D058868:Compressed Air; D019416:Head Movements / Q000502:physiology; D006801:Humans; D007568:Jaw / Q000502:physiology; D008297:Male; D010865:Pilot Projects; D015742:Propofol / Q000008:administration & dosage*; D012371:Robotics / Q000295:instrumentation* / Q000379:methods; D055815:Young Adult
chemical_list: D018686:Anesthetics, Intravenous; D015742:Propofol
keywords: Anesthesia; Jaw closure; Pneumatic actuator; Positional change; Upper airway patency