title: The influence of head and neck position on ventilation with the i-gel airway in paralysed, anaesthetised patients.
abstract: OBJECTIVE
  We hypothesised that head and neck position could affect the effectiveness of ventilation with the i-gel airway. To test this hypothesis, we investigated the influence of different head and neck positions on oropharyngeal sealing pressures and ventilation scores during ventilation with i-gel.
  
  
  METHODS
  A single, experienced supraglottic airway device user inserted the i-gel in 20 paralysed, anaesthetised patients who were scheduled for oral surgery. Oropharyngeal leak pressures and ventilation scores were measured with the head and neck in the neutral position, flexed, extended or rotated to the right. Ventilation was scored from 0 to 3 based on three criteria (no leakage with an airway pressure of 15 cmH2O, bilateral chest excursion and a square wave capnogram; each item scoring 0 or 1 point).
  
  
  RESULTS
  Compared with the neutral position (25.8 ± 5.2 cmH2O), oropharyngeal leak pressure was significantly higher with flexion (28.5 ± 3.4 cmH2O, P=0.015) and lower with extension (23.0 ± 4.2 cmH2O, P=0.015), but similar with rotation (26.7 ± 5.1 cmH2O, P=0.667). Flexion of the head and neck [2 (1-3)] adversely affected the ventilation score compared with the neutral position [3 (2-3), P=0.004].
  
  
  CONCLUSIONS
  Effective ventilation with an i-gel can be performed in patients in whom the head and neck is extended or rotated, whereas flexion of the head and neck adversely affects ventilation. Clinically, flexion of the head and neck should be avoided during ventilation with the i-gel.
authors.affiliation: Department of Anesthesiology, Osaka Dental University, Osaka, Japan. odu9847@yahoo.co.jp
authors.forename: Takuro
authors.initials: T
authors.lastname: Sanuki
authors.forename: Rumiko
authors.initials: R
authors.lastname: Uda
authors.forename: Shingo
authors.initials: S
authors.lastname: Sugioka
authors.forename: Erina
authors.initials: E
authors.lastname: Daigo
authors.forename: Hiroki
authors.initials: H
authors.lastname: Son
authors.forename: Masafumi
authors.initials: M
authors.lastname: Akatsuka
authors.forename: Junichiro
authors.initials: J
authors.lastname: Kotani
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D058109:Airway Management / Q000295:instrumentation / Q000379:methods*; D000768:Anesthesia, General / Q000379:methods; D005260:Female; D006257:Head; D006801:Humans; D008297:Male; D008875:Middle Aged; D009333:Neck; D019647:Oral Surgical Procedures / Q000379:methods; D009960:Oropharynx; D010243:Paralysis / Q000150:complications*; D011187:Posture; D011312:Pressure; D012121:Respiration, Artificial / Q000295:instrumentation / Q000379:methods*; D055815:Young Adult