Background: Brachial Plexus block is the easiest and simplest form of providing anesthesia for upper limb surgeries. It is known that potassium added to local anesthetics can increase the extracellular concentration, time of depolarization and prolongation of action of the local anesthetics. With this in background, this study was designed to observe the effect of potassium chloride as adjuvant to local anesthetics on onset of sensory and motor blockade and qualitative block for analgesia.

Materials and Methods: Forty patients of ASA I and II of either sex, aged 17 to 61 years posted for upper limb orthopaedic surgeries received either plain Inj. Xylocaine 1.5% (A1), Inj. Xylocaine 1.5% with Inj. Potassium Chloride 0.2 mmol (A2), plain Inj. Bupivacaine 0.375% (B1) or Inj. Bupivacaine 0.375% with Inj. Potassium Chloride 0.2 mmol (B2) in Brachial Plexus block through Supraclavicular approach. Patients were assessed for the onset of sensory and motor blockade, duration of anaesthesia and post-operative analgesia.

Result: Groups A2 and B2 (potassium added groups) had faster onset of sensory and motor blockade, and prolonged duration of action than A1 and B1 (plain Xylocaine and Bupivacaine) groups. The quality of blockade was better in groups with added potassium, more so with Bupivacaine than with Xylocaine.

Conclusion: Addition of Potassium chloride to Xylocaine and Bupivacaine had significant clinical advantage over Plain drugs specially Bupivacaine on onset time, duration and quality of sensory and motor blockade in Brachial Plexus block.