Background: Ropivacaine has been chosen for supraclavicular brachial plexus blockfor its safety profile. Magnesium Sulphate is used as an adjuvant to local anaesthetics as it is known to potentiate sensory and motor blockade.

Aims: Our aim was to assess and compare the effectiveness of adding Magnesium Sulphate to Ropivacaine for supraclavicular brachial plexus block.The variables compared included onset, duration of sensory and motor blockade and duration of analgesia. Any adverse effects were also documented.

Methods: A prospective randomized double blinded controlled study was conducted involving 50 adult patients between the ages of 20 and 50 years belonging to American Society of Anaesthesiologists (ASA) grade 1 and 2 who underwent upper limb orthopaedic surgeries. Patients were randomly assigned into two groups of 25 each. Group R was administered 0.75% Ropivacaine while Group RM received 0.75% of Ropivacaine along with 250 mg Magnesium Sulphate. Sensory and motor blockade characteristics along with analgesic efficiency was determined.

Statistical analysis: The collected data was entered and tabulated in Microsoft excel and were subjected to analysis using SPSS version 16.0. Student t test was used for analysis of the demographic and hemodynamic data. Unpaired t test was used for statistical evaluation of the data which comprised of onset, duration of both sensory and motor blockade as well as duration of analgesia. The results were statistically significant if p value obtained was <0.05. P value < 0.001 was considered as highly significant statistically.

Results: Patients in group RM had rapid onset of sensory and motor blockade (7.8±1.24min v/s 9.6±1.76min and 10.36±1.22min v/s 12.24±2.26min). There was also prolongation of sensory and motor blockade along with reduced analgesic requirements in the post operative period.

Conclusion: Adding Magnesium Sulphate to 0.75% Ropivacaine provided faster onset and longer duration of sensory and motor blockade along with superior post operative analgesia without any adverse effects.