Middleton PM, Simpson PM, Thomas RE, Bendall JC. Resuscitation. 2014 Jul;85(7):893-7
Subjects with out-of-hospital cardiac arrest were allocated to either the i-gel or Portex Soft Seal laryngeal mask group, within a large Australian ambulance group. Primary outcome was successful insertion of the airway. The i-gel had a significantly higher success rate than Portex Soft Seal and significantly lower median ease of insertion scores.
Link to abstract