Introduction : The interscalene approach to the brachial plexus for shoulder surgeries provides excellent anaesthesia with remarkable safety and minimal or no systemic disturabances.
Material and Methods : 60 abult patients ASA I-II undergoing elective shoulder surgery. Patients were randomly allocated into 3 groups. The patients recived 20ml of either ropivacaine 1% GI (20 patients), ropivacaine 0.75% GII (20 patients) and bupivacaine 0.5% GIII (20 patients). Onset time of sensory and motor block, duration of analgesia and the need for supplementary analgesics were recorded. Pain was assessed by using VAPS. Haemodynamic parameters, oxygen saturation and respiratory rate were recorded. Unwanted side effects, cardiovascular, neurological, nausea and vomiting etc were recorded. Also, patients satisfaction were noted.
The pharmacological study was done on pentobarbitone cats to determine the effect of different doses of ropivacaine (0.35-2.8mg/kg) versus buipvacaine (0.5-4mg/kg) on arterial blood pressure, ECG and respiratory rate.
Results: The mean onset time of analgesia was faster in ropivacaine groups than bupivacaine group (p‹0.005). The studied groups were comparable regarding the duration of analgesia, motor and sensory block, cadio vascular and respiratory effects. The incidence of paraesthesia was more frequent in bupivacaine group than both ropivacaine groups (30% vs 10%) There was more patient satisfaction in ropivacaine groups than bupivacaine groups.
On the other hand the pharmacological study showed that ropivacaine had more less toxic effects on cardiovascular and respiratory systems.
Conclusion : This study concluded that interscalene block performed with either 0.75% or 1% ropivacaine allows for a prolonged postoperative pain relief similar to bupivacaine 0.5%
with shorter onset time, more cardiovascular
Introduction :
Interscalene brachial plexus block (ISB) is used to provide anaesthesia and analgesia for shoulder surgery. Single injection interscalene brachial plexus block is an effective anaesthetic; however it is limited by the duration of action of local anaesthetic. Bupivacaine and ropivacaine have been compared both at different an equal volumes and concentration for ISB. Kinnard and Lirette, (1996).
Bupivacaine is a long-acting local anaesthetic which has been reported to be associated with slower onset time for nerve blockade compared with other intermediate
stability and higher patient satisfaction.