Midazolam with bupivacaine for improving analgesia quality in brachial plexus block for upper limb surgeries

To compare the onset, duration and postoperative pain scores of supraclavicular block with bupivacaine alone and bupivacaine-midazolam combination.

Randomized controlled clinical trial.

The Postgraduate Medical Institute, Hayatabad Medical Complex, Peshawar, from April 2005 to June 2007.

A randomized controlled clinical trial was conducted on 50 ASA-I or II adult patients undergoing upper limb surgeries under supraclavicular brachial plexus block. Patients were randomly allocated into two groups of 25 each. Patients in group A were administered 30 ml of 0.5% bupivacaine and those in group B were given 30 ml of 0.5% bupivacaine with midazolam 50 microg x kg-1. Hemodynamic variables (heart rate, noninvasive blood pressure, oxygen saturation), pain scores, rescue analgesic requirements and sedation score were recorded for 24 hours postoperatively, and compared using ANOVA with significance at p <0.05.

The onset and duration of sensory and motor block was significantly faster and longer in group B compared to group A (p < 0.001). Pain scores were significantly lower in group B for 24 hours postoperatively (p < 0.001). Demand for rescue analgesic were significantly less in group B. Hemodynamics and sedation scores did not differ between the groups in the studied period.

Bupivacaine (0.5%) in combination with Midazolam (50 microg x kg-1) quickened the onset as well as prolonged the duration of sensory and motor blockade of the brachial plexus for upper limb surgery. It improved postoperative analgesia without producing any adverse events compared to plain bupivacaine (0.5%) in equal volume.