Evaluation of pH in the removed i-gel after general anesthesia: a prospective observational study. 1. May 2016 sam Anaesthesia (0) Deguchi S, Komasawa N, Kido H, Omori M, Minami T. J Clin Anesth. 2016;30:61-2 Study to test the pH levels in the i-gel after removal. Link to abstract