title: Does prewarming the i-gel supraglottic airway device fit the larynx better compared to keeping it at room temperature for non-paralysed, sedated patients: a randomised controlled trial.
abstract: OBJECTIVE
  This study aimed to test the hypothesis that the i-gel supraglottic airway device would fit the larynx and provide better sealing pressure if prewarmed to 42°C relative to the device kept at room temperature in non-paralysed, sedated patients.
  
  
  METHODS
  A total of 74 adult patients were assigned to the warm (i-gel prewarmed to 42°C; W group; 37 patients) or the control (i-gel kept at room temperature; C group; 37 patients) groups. Anaesthesia was induced with propofol and fentanyl. The i-gel was prewarmed to 42°C for 30 min before insertion in the W group, but kept at room temperature (approximately 23°C) for the C group. The number of attempts made until successful insertion and sealing pressure were compared between the two groups.
  
  
  RESULTS
  Insertion was successful with one attempt in 35 cases each for the W and C groups. Two attempts were needed in two cases for the W group and one case for the C group. There was one failed attempt in the C group, but none in the W group. None of the differences between the two groups were significant (p=0.51). Sealing pressure was slightly, but not significantly, higher in the W group than in the C group (W group 22.6±6.1 cm H2O; C group 20.7±6.1 cm H2O; p=0.15).
  
  
  CONCLUSIONS
  Prewarming of the i-gel to 42°C did not increase the success rate of insertion, nor did it significantly increase sealing pressure in anaesthetised, non-paralysed patients. Our data suggest that we can keep the i-gel at room temperature for emergency airway management for non-paralysed, sedated patients.
  
  
  BACKGROUND
  University Medical Information Network, Japan 000012287.
authors.affiliation: Department of Anaesthesiology, Osaka Medical College, Takatsuki, Osaka, Japan.
authors.forename: Nobuyasu
authors.initials: N
authors.lastname: Komasawa
authors.affiliation: Department of Anaesthesiology, Hokusetsu General Hospital, Takatsuki, Osaka, Japan.
authors.forename: Isao
authors.initials: I
authors.lastname: Nishihara
authors.affiliation: Department of Anaesthesiology, Osaka Medical College, Takatsuki, Osaka, Japan.
authors.forename: Shinichi
authors.initials: S
authors.lastname: Tatsumi
authors.affiliation: Department of Anaesthesiology, Osaka Medical College, Takatsuki, Osaka, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Minami
mesh_terms: D000328:Adult; D000368:Aged; D058109:Airway Management / Q000295:instrumentation / Q000379:methods*; D000758:Anesthesia / Q000379:methods*; D000768:Anesthesia, General; D004209:Disposable Equipment; D020724:Elastomers; D004867:Equipment Design; D005260:Female; D005782:Gels; D006801:Humans; D007442:Intubation, Intratracheal; D017214:Laryngeal Masks; D007830:Larynx; D008297:Male; D008875:Middle Aged; D011312:Pressure; D013696:Temperature
chemical_list: D020724:Elastomers; D005782:Gels