Lead Sponsor

Hallym University Kangnam Sacred Heart Hospital

Age

18 - 80 years

Sex

ALL

Healthy Volunteers

Yes

•patients of ASA physical status 1-2 who were scheduled for elective surgery under general anaesthesia requiring tracheal intubation

•if they required rapid sequence induction; had a history of previous difficult direct laryngoscopy and required awake tracheal intubation; were unable or unwilling to provide informed consent; had uncontrolled hypertension; had a history of ischaemic heart disease without optimal control of symptoms; had a history of acute or recent stroke or myocardial infarction; had cervical spine instability or cervical myelopathy; had symptomatic asthma or reactive airway disease requiring daily pharmacological treatment for control of symptoms; or had a history of gastric reflux.