AN ASSESSMENT OF PRILOCAINE AS A TOPICAL ANESTHETIC AGENT FOR FIBEROPTIC BRONCHOSCOPY IN COMPARISON WITH LIDOCAINE

We have evaluated prilocaine as a topical anaesthetic agent for fibreo ptic bronchoscopy in comparison with lidocaine in terms of efficacy an d safety. Forty patients were included in a randomised double-blind pa rallel-group study. Efficacy was assessed using visual analogue scales , a patient ranking scale and the number of doses of local anaesthetic and intravenous sedative required. Measures of toxicity included peak plasma concentration of local anaesthetic, whether supplementary oxyg en was needed and change in methaemoglobin concentration. For most of the outcome variables, the medians and quartiles were similar for the two local anaesthetics. However, the median peak plasma concentration of prilocaine (0.5 mu g.ml(-1)) was less than one-third that of lidoca ine (1.76 mu g.ml(-1)). The merits and hazards of using multiple-regre ssion modelling to improve the precision of the analysis of the result s are considered. We conclude that prilocaine can be used successfully as a topical anaesthetic agent for fibreoptic bronchoscopy and is ass ociated with a lower risk of toxicity.