Finding a better nasal anaesthetic: the efficacy of tetracaine and oxymetazoline as a topical nasal anaesthetic and decongestant for people having nasal endoscopy

Cophenylcaine (a combination of lignocaine and phenylephrine, a local anaesthetic and decongestant respectively) is commonly used as a spray to make the inside of the nose numb in Otolaryngology (ear, nose and throat surgery) clinics. However, other local anaesthetics like tetracaine are more potent than lignocaine, and phenylephrine tastes very bitter whereas other decongestants like oxymetazoline are essentially tasteless. Our hypothesis is that using a tetracaine/oxymetazoline spray instead of cophenylcaine will make nasal endoscopy more comfortable. We will enrol participants from tertiary rhinology (sinus and nose surgery) clinics who are having nasal endoscopy as a part of their care. Tetracaine/oxymetazoline will be sprayed in one nostril and cophenylcaine will be sprayed in the other. This will be randomised and neither the participant nor the specialist performing endoscopy will know which spray was used on which side. Both the participants and the specialists will fill out simple questionnaires after nasal endoscopy the comfort of the procedure on each side and the tolerability of the sprays themselves. This will help to determine whether people find nasal endoscopy more comfortable with tetracaine/oxymetazoline, and whether clinicians prefer tetracaine/oxymetazoline over cophenylcaine for topical anaesthesia prior to nasal endoscopy.