Comparing propofol anaesthesia guided by Bispectral Index monitoring and frontal EEG wave analysis with standard monitoring in laparoscopic surgery: protocol for the 'EEG in General Anaesthesia - More Than Only a Bispectral Index' Trial, a multicentre, double-blind, randomised controlled trial. - Gruber BU; Girsberger V; Kusstatscher L; Funk S; Luethy A; Jakus L; Maillard J; Steiner LA; Dell-Kuster S; Burkhart CS (BMJ open, 2022)