It was with great interest that I read McKevith's correspondence highlighting a lack of knowledge around the use of lipid emulsion for local anaesthetic toxicity [1].

I recently undertook a wider range survey, e-mailing an electronic questionnaire to every doctor in my Trust. Participants were surveyed on their use of local anaesthetic (LA) drugs, were asked to perform a dose calculation, and asked for maximum recommended doses of three commonly used agents (plain lidocaine, lidocaine with epinephrine, and bupivacaine). Participants were asked to declare necessary standards of monitoring when using local anaesthetics and were invited to identify features of local anaesthetic toxicity. Finally, participants were asked whether they were aware of any specific treatment for local anaesthetic toxicity and questioned as to guidelines on its use. 91 responses were collected over a period of three weeks; 22 (24%) of the questionnaires were completed by anaesthetists.

The results were striking. All responding anaesthetists could calculate the dose of LA contained in 10mls of a 1% solution compared to 36% of non-anaesthetists. 50% of general surgeons, orthopaedic surgeons, obstetricians and gynaecologists admitted to LA use on a daily or weekly basis and half of these participants correctly calculated the dose. More anaesthetists knew the maximum recommended doses of plain lidocaine, lidocaine with epinephrine and bupivacaine (68%, 82%, 73% respectively) than non-anaesthetists (15%, 25%, 14% respectively).

On the subjects of monitoring and toxicity recognition, participating anaesthetists regarded the following 'essential' when giving potentially toxic doses of local anaesthetics: intravenous cannulation (95%), electrocardiogram monitoring (86%), blood pressure monitoring (73%), oxygen saturation monitoring (64%) and availability of a resuscitation trolley (86%). In general, non-anaesthetists felt that somewhat lower standards were acceptable with 64% regarding intravenous cannulation to be essential and 74% thought that the availability of a resuscitation trolley was necessary. All anaesthetists recognised that local anaesthetic toxicity could be responsible for cardiac arrhythmia or arrest compared to 93% and 81% of non-anaesthetists. With regard to circumoral parasthesia, 95% of anaesthetists recognised this sign compared to 61% of non-anaesthetists.

Finally, participants were surveyed about the treatment of LA toxicity. 95% of anaesthetists were aware of the use of lipid emulsion compared to just 7% of non-anaesthetists. Although 82% of anaesthetists knew where the nearest bag of lipid emulsion was kept, only 41% (3% of non-anaesthetists) knew the initial dose.

These results reinforce McKevith's assertion that while there is good awareness of local anaesthetic safety among anaesthetists, there is poor knowledge in other specialties. Accordingly, in my centre we intend to incorporate education on local anaesthetic safety and treatment of LA toxicity in mandatory resuscitation training sessions. I would encourage other centres to do the same.

[1] McKevith J, Rathi S, El Sayed H, Mills K. Lipid emulsion: is there sufficient knowledge among hospital staff? Anaesthesia 2009; 65: 535-536