Flexible Fibrescope Versus Video Laryngoscope for Nasotracheal Intubation - A Randomised Comparison

Patients having surgery under general anaesthesia require insertion of a breathing tube to keep the airway open. The technique of inserting a breathing tube through the nose into the trachea (airway) is known as nasotracheal intubation. This is the ideal airway for surgical procedures performed inside the mouth such as complex teeth extractions and operations on the jaw.

Traditionally, the breathing tube is initially inserted blindly into the nasal cavity, then a video laryngoscope (a camera device) or a direct laryngoscope is used to visualise and guide the passage of tube into the trachea. This approach can be associated with difficulty passing the tube and a has high incidence of nasal trauma and nosebleed. A flexible fibrescope ( flexible camera device) with pre-loaded tracheal tube is passed through the nostril first under vision, gently advanced through the nasal passage and then to the trachea. Once it is correctly placed in the trachea, the breathing tube is railroaded over it. This procedure allows to visualise the nasal passage and to choose most patent nostril and hence likely to reduce risk of nosebleed as compared blind passage of tube through the nose. A videolaryngoscope has a camera on the blade that projects the image onto a monitor screen. As this is a rigid device, it can only be inserted through the oral cavity and allows the advancement of tube into the trachea. Both these techniques are currently used in the clinical practice. However, there are no studies to inform the anaesthetists whether there are any differences in the incidence of nosebleed.

We wish to do a randomised comparison between flexible fibrescope and videolaryngocope in terms reducing the risk and severity of nosebleed.

Patients aged 18 and above, presenting for elective surgical procedures and requiring general anaesthesia and nasal intubation will be invited to take part in the study. We are aiming to recruit 200 participants (see sample size section) to see any significant differences in the incidence of nosebleed.

Patients who are eligible and consent to take part in the study will be randomly allocated either to flexible fibrescope group or to videolaryngoscope. At the time of nasotracheal intubation, smoothness of nasal intubation, severity of bleeding from the nose and time taken to complete the tracheal intubation will be noted. Five minutes after intubation, the surgeon performing surgery (blinded to the technique of intubation) will be examining the oral cavity for any bleeding. This will be graded using a standardised nasal bleeding score. All patients will be visited in the post operative period to check any ongoing nosebleed and nasal discomfort. Patient details that will be collected includes gender, age, weight, height, body mass index and airway assessment parameters. No other personal data is required.

This study aims to see whether the use of flexible fibrescope reduces nasal bleeding and improves patient safety. If there is no difference, it may provide reassurance in the continued use of video laryngoscopy for nasal intubation.