[Addition of muscle relaxants to intravenous regional anesthesia]

Nine volunteers received two intravenous regional anaesthetics in the right arm. The first anaesthetic was performed with plain 0.25% lignocaine (dose 1 ml/kg body weight), the second with the same volume of lignocaine, with the addition of 0.5 mg pancuronium-Bromide. Latency for onset of the following was measured in both groups: 1. analgesia, 2. cold sensation, 3. warm sensation, 4. touch, 5. motor blockade. As expected, the addition of pancuronium had no influence on sensory blockade, however, motor block was significantly stronger, faster in onset, and longer in duration. Significant systemic side effects after pancuronium were not observed. No pancuronium was found in flame photometry plasma studies. On the basis of these investigations, one can recommend, for I.V.R.A., a relatively large volume of dilute local anaesthetic solution and, to achieve better muscle relaxation, the addition of 0.5 mg of pancuronium.