A Randomised Controlled Trial of Intubation by Inexperienced Anaesthetists, Comparing the The Pentax Airway Scope AWS-S100 Rigid Video Laryngoscope(Pentax AWS) and the Macintosh Laryngoscope.

General anaesthesia often requires that the trachea be protected by intubation. This involves placement of a cuffed endotracheal tube into the trachea, after the onset of unconsciousness and muscle relaxation. Usually this requires the anaesthetist to obtain a direct view of the patient's vocal cords via the mouth, using a laryngoscope such as the Macintosh laryngoscope. The endotracheal tube is then guided through the vocal cords into the trachea.

Difficult or failed intubation, is a potentially serious and occasionally life threatening complication. This is the unexpected inability to place the endotracheal tube in the correct place. The commonest cause is a failure to achieve an adequate view of the vocal cords at laryngoscopy.

Failed or difficult intubation significantly delays establishment of a secure airway and therefore can lead to major morbidity from hypoxia and/or aspiration of gastric contents. Other morbidity can also ensue from delay to the procedure in emergency situations or airway trauma due the various devices used or the force required to secure intubation. Whilst all anaesthetists and their assistants are trained to deal with difficult or failed intubations, disasters do occur. For example, in obstetrics, the previous Confidential Enquiry into Maternal Deaths reported five of the six deaths directly due to anaesthesia were related to intubation difficulties.

The Pentax Airway Scope AWS-S100 (Pentax AWS), Rigid Video Laryngoscope for Intubation is a new self-contained video laryngoscope with an integral colour-viewing screen mounted on the handle. A camera at the tip transmits an indirect image, which obviates the need to obtain a direct view of the vocal cords. It requires no prior set-up of equipment and is intuitive to use for anyone already competent in traditional direct laryngoscopy. Previously conducted evaluations of the scope have been presented and show that intubation can be secured within a clinically normal time span by various grades of anaesthetists in various clinical situations. Authors are currently suggesting it has a role as a back-up device for difficult intubations and for training. One has been obtained for the Foresterhill site for these purposes.

RATIONALE The simplicity of use and intuitive function of the Pentax AWS suggests it may have a wider role than as a back-up and could possibly be the first-line laryngoscope for situations where difficulty with intubation is more likely or more hazardous.