Randomised controlled trials (RCTs) in participants of any age who underwent FFN for any reason and who were treated with a preparative agent were eligible for inclusion.
The primary outcome was the patient’s evaluation of FNN, such as pain, discomfort and taste unpleasantness; these were primarily measured by visual analogue scales (VAS). Secondary outcomes were the endoscopist’s evaluation of treatment, such as ease of examination and quality of view. Trials in participants with rigid endoscopy or flexible endoscopy other than FNN were excluded. Trials in patients who had already received FNN were excluded.
The included trials compared topical anaesthetic plus vasoconstrictor (co-phenylcaine), topical anaesthetic only (lidocaine, tetracaine hydrochloride), vasoconstrictor only (ephedrine, xylometazoline spray) or lubricant (K-Y jelly) with other preparative agent, saline or nothing. Reported outcomes included VAS (0-10 or 0-100) of pain, discomfort, bad taste, burning or choking, five-point discomfort scale and quality of view.
One reviewer undertook study selection.