Establish Whether Hyperangulated Videolaryngoscopy (HAVL) Can be Used to Facilitate Tracheal Intubation Effectively and Safely in Unselected Adult Patients; Describe the Population in Whom HAVL Fails to Facilitate Tracheal Intubation Successfully, Identifying Any Contributory Characteristics.

When patients have a general anaesthetic (go to sleep for surgery), the anaesthetist often places a small tube into their windpipe (intubation) to help them breathe. To see exactly where to put the tube, the anaesthetist uses a device called a laryngoscope.

A commonly used laryngoscope is the McGrath videolaryngoscope. It has a small camera and screen to help guide safe placement of the tube. It comes in two different shapes - one shaped in the same way laryngoscopes have been shaped for the last 80 years, and another newer design (McGrath X-blade) that matches the curve of patients' tongues better.

All different classes of videolaryngoscope have been shown to have benefits to patients; however, the best videolaryngoscope shape has yet to be determined.

The McGrath X-blade is currently recommended in patients in whom the anaesthetist thinks it might be slightly more difficult to place the tube, but some anaesthetists already prefer to use it in all their patients. This is not a new device or a new technique.

In this study, the investigators wish to explore if there is any special benefit of using it in all patients, by collecting some information when the device is used.