Thiopentone or propofol for LMA insertion?

We read the article by Bapat et al., 1 with interest. They demonstrated the good quality of laryngeal mask (LMA) insertion with midazolam-thiopentone and the poor conditions with lidocainethiopentone. We would like to bring to your attention two studies we published earlier this year. In the first 2 we showed that topical 40 mg lidocaine followed by 5 mg-kg -1 thiopentone produced conditions for LMA insertion that were as good as those with 2.5 mg.kg q propofol. The lidocaine thiopentone group had less haemodynamic depression and a shorter period of apnoea. In a second study we compared the topical lidocaine-thiopentone group with iv lidocaine (at doses of 0.5 or 1.5 mg.kg -I) before thiopentone. The conditions for insertion were poor in both iv groups (poor or unacceptable in 42%) but excellent or good in 87% of the topical group. As in Bapat's study all our patients also received fentanyl 1 lag.kg -j propofol. Our findings suggest that an acceptable alternative to Batap's technique of fentanylmidazolam-thiopentone is fentanyl-topical lidocaine-thiopentone. This has the advantages of good haemodynamic stability and briefapnoea. As a smaller dose oflidocaine is used the possibility of lidocaine toxicity is low. Finally, the technique is cheaper than the fentanyl-midazolamthiopentone technique. Topical 40 mg lidocaine costs approximately 6 cents.