Local anaesthetic dilemma

Editor - I have just finished my fifth year attachment in general surgery and would like to highlight an issue that has become apparent to me. During my first surgical on call I was asked by my house officer to put a brown (14 gauge) venflon into a fairly ill patient who was bleeding from the rectum. I asked the preregistration house officer (pRhO) to write me up for some 2% lignocaine to be used as a intradermal local anaesthetic before inserting the venflon. he said that it wasn't needed.

This comment surprised me. During the rest of my attachment I asked surgical pRhOs, senior house officers (ShOs), and specialist registrars (SpRs) whether they would use lignocaine when inserting brown or grey (16 gauge) venflons. Of over 20 doctors surveyed, only one replied that they would use lignocaine.

I also asked ShOs, SpRs, and consultants in anaesthetics whether they would use lignocaine before inserting brown or green venflons. Of over 20 doctors surveyed, all replied that they would use lignocaine before inserting a brown or grey venflon. Many also said that they would use local anaesthetic before inserting a green (18 gauge) venflon. My small survey suggests that there is a difference in opinion between doctors in the two specialties. There is evidence that suggests that local anaesthetic should be used before intravenous cannulation. A recent study by Cooper et al showed that in 36 patients no pain was felt when brown or grey cannulae were inserted one minute after local anaesthetic injection.¹

These patients rated the pain caused by the local anaesthetic injection as being 2/10 in severity. Some doctors suggested that use of local anaesthetic can make the procedure more difficult by obscuring the vein. Previous work has shown that this is not the case and that the success rate is similar whether or not local anaesthetic is used.²

As doctors we live by the motto of doing no harm to our patients. use of local anaesthetic will help to make the wide bore IFF cannulation procedure far less painful for patients. Next time you are inserting a grey or brown venflon, ask yourself whether you would want it inserted into your own arm without any local anaesthetic.

Daniel Sado, fifth year medical student, university of Southampton
Email: dan-sado@yahoo.com


studentBMJ 2001;09:357-398 October ISSN 0966-6494

1. Cooper jA, Bromley LM, Baranowski Ap, Barker SgE. Evaluation of a needle free injection system for local anaesthetic prior to venous cannulation. Anaesthesia 2000;55:247.50.
2. Langham BT, harrision DA. Local anaesthetic: does it really reduce the pain of insertion of all sizes of venous cannula? Anaesthesia 1992;47:890.1.