A primary aim of anaesthesia is to prevent awareness of surgery; ablation of the experience of surgery is the most secure way to prevent awareness with recall. Fortunately the incidence of awareness with recall (the patient can spontaneously remember the intraoperative event) is very rare (0.1-0.2%). However the investigators systematic review suggests that consciousness of intraoperative events may occur in approximately 37% of patients in experimental studies (as identified by the validated clinical procedure the isolated forearm test that does not require postoperative recall of the event). In this international cohort study, recruiting a minimum sample of 200 patients, the investigators will investigate the incidence of anaesthesia awareness (as identified by the isolated forearm test) following the induction of anaesthesia and before surgery.

Inclusion Criteria:

• Adult patients clinically requiring intubation will be included in this cohort.
• Patients must be able to follow the isolated forearm technique commands when awake and prior to their operation will be included in this cohort.

Exclusion Criteria:

• Contraindication to isolated forearm technique test such as unable to have tourniquet on arm for the isolated forearm technique (e.g. lymphedema or operative site).

Adult patients undergoing anaesthesia requiring intubation and layngoscopy