Clonidine prolongs the effect of ropivacaine for axillary brachial plexus blockade.

PURPOSE: To evaluate the effect of adding clonidine to ropivacaine, for axillary brachial plexus blockade, on the onset and duration of sensory and motor block and duration of analgesia. METHODS: In a prospective randomised double blind placebo controlled study axillary brachial plexus blockade was performed in 50 patients using 40 ml ropivacaine 0.75%. Group (A) had 150 microg clonidine and Group (B) 1 ml normal saline added to the local anesthetic. Sensory function was tested using pinprick (sharp sensation, blunt sensation or no sensation) and temperature with an ice cube compared with the opposite arm, (cold/not cold). Motor function was assessed using a modified Bromage scale. Postoperative analgesia was standardised. Onset and duration of sensory and motor blockade, duration of analgesia, postoperative pain score, and analgesic requirement were compared. RESULTS: The clonidine patients showed an increase in duration of sensory loss from 489 min to 628 min with a mean difference of 138 min (95% confidence interval of 90 to 187 min), motor blockade from 552 min to 721 min with a mean difference of 170 min (95% confidence interval of 117 to 222 min), and analgesia from 587 min to 828 min with mean difference of 241 min (95% confidence interval of 188 to 294 min). There was no difference in onset time. No side effects were noted. CONCLUSION: The addition of 150 microg of clonidine to ropivacaine, for brachial plexus blockade, prolongs motor and sensory block and analgesia, without an increased incidence of side effects.

Tracheal intubation without neuromuscular block in children.

We have studied 80 healthy children, aged 2-14 yr, undergoing adenotonsillectomy in a double-blind, randomized design. Tracheal intubation facilitated by either suxamethonium 1.5 mg kg-1 or alfentanil 15 micrograms kg-1 was compared after induction of anaesthesia with propofol 3-4 mg kg-1. The quality of tracheal intubation was graded according to the ease of laryngoscopy, position of the vocal cords, coughing, jaw relaxation and movement of limbs. There were no significant differences in the overall assessment of intubating conditions between the two groups, and all children underwent successful tracheal intubation. Fewer patients coughed (P < 0.014) and limb movement was less common (P < 0.007) after tracheal intubation facilitated by suxamethonium. Alfentanil attenuated the haemodynamic responses to tracheal intubation.