Effect of adding midazolam to bupivacaine in supraclavicular brachial plexus block

Objective: Supraclavicular approach to brachial plexus block one of the methods in which brachial plexus can be blocked by different types of local anesthetics and many studies demonstrated addition of different material to local anesthetics to improve either the onset or quality of postoperative analgesia. This prospective, randomized, observer blinded study evaluated the onset, duration and degree of sensory and motor blocking action of different doses of midazolam added to bupivacaine in supraclavicular brachial plexus block . Method: Sixty adult patients admitted to Mansoura University Hospital and scheduled for upper limb orthopedic surgery under supraclavicular approach using paraesthesia technique were randomly assigned into 3 groups to receive single dose of 30 ml of 0.5 % isobaric bupivacaine mixed with saline as placebo(B group -control) ,30 ml of 0.5 % isobaric bupivacaine mixed with midazolam 50 μg/kg (BM 50 group),30 ml of 0.5 % isobaric bupivacaine mixed with midazolam 100μg/kg (BM 100 group). Onset ,duration and degree of sensory and motor blocking, pain score using VAS ,duration of effective analgesia,hemodynamics and arterial oxygen saturation and sedation score were recorded at several time points. Results :The results of the present study showed that addition of midazolam perineurally to isobaric bupivacaine didn't affect significantly the onset ,duration and degree of motor and sensory block .There were no significant difference as regard heart rate ,mean arterial blood pressure , oxygen saturation and sedation score in the studied groups. There was significantly lower VAS in Group BM 100 at 5 hours postoperatively in comparison with B group. Conclusion: From the previous results it was concluded that the onset , duration and degree of sensory and motor blockade as well as the duration of post operative analgesia did not affected by the addition of either 50 μg/kg or 100 μg/kg midazolam to bupivacaine in supraclavicular brachial plexus block. We did not recommend the addition of midazolam to bupivacaine for brachial blexus block.