Komasawa N, Nishihara I, Tatsumi S, Minami T. BMJ Open. 2015 Jan 13;5(1):e006653
Patients were assigned to a warm (at 42 degrees centigrade) or control room temperature group. Number of attempts until successful insertion and sealing pressure were compared. Authors conclude that pre-warming did not increase insertion success rate.
Link to abstract
Nishiyama T, Kohno Y, Kim HJ, Shin WJ, Yang HS. The American Journal Of Emergency Medicine 2012; 30(9): 1756- 1759
180 patients were randomised into two equal groups, one for insertion of i-gel® at room temperature, the other at 37 degrees centigrade. Insertion time, number of insertion attempts, inspiratory and leak pressures, and leak fraction were compared. Report found no significant difference between the two groups.