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Updated: Apr 20, 2026

Esophageal Heat Transfer for Patient Temperature Control and Targeted Temperature Management
Published on: November 21, 2017
Prewarming of the i-gel facilitates successful insertion and ventilation efficacy with muscle relaxation: a
Nobuyasu Komasawa1, Isao Nishihara2, Shinichi Tatsumi1
1Department of Anesthesiology, Osaka Medical College, Takatsuki, Osaka, Japan.
Study Objective:
To determine if prewarming of the i-gel (Intersurgical, Wokingham, United Kingdom) improves insertion and ventilation efficacy with muscle relaxation in patients undergoing elective surgery.
Design:
Clinical randomized study.
Setting:
Operating room.
Patients:
Sixty-eight adult patients scheduled for elective surgery under general anesthesia with American Society of Anesthesiologists physical status 1-3.
Interventions:
The i-gel was warmed to 42°C for 30 minutes before insertion (W group; 34 patients) or kept at room temperature (approximately 23°C) (C group; 34 patients).
Measurements:
The number of attempts for a successful insertion and the sealing pressure and leak volume 30 seconds and 30 minutes after initiating mechanical ventilation.
Main Results:
The total insertion attempts were 1 (W group, 31 cases; C group, 24 cases) and 2 (W group, 3 cases; C group, 10 cases), which was significant (P = .001). Sealing pressure was significantly higher in the W group than the C group (W group, 21.8 ± 3.7 cm H2O; C group, 18.5 ± 3.4 cm H2O; P = .001). Leak volume was significantly smaller after 30 seconds in the W group than the C group (P = .002), but not after 30 minutes (P = .69).
Conclusions:
Prewarming the i-gel to 42°C demonstrated a higher successful ventilation initiation.
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