Efficacy of lignocaine in alleviating potassium chloride infusion pain

A double-blind study was set up to investigate the effect of pretreatment with lignocaine on the incidence of potassium chloride infusion pain. Twenty-eight patients were randomly allocated into two equal groups. Patients in both groups were hypokalaemic and were scheduled for replacement consisting of potassium chloride 20 mmol diluted to 100 ml in dextrose 5% solution administered over two hours. Group A (lignocaine) patients were pretreated with a bolus dose lignocaine 3 ml 1%, Group B (control) received isotonic saline 3 ml. The incidence of potassium chloride infusion pain was significantly reduced in Group A. There was no adverse effect reported. This study demonstrates the efficacy of bolus dose of lignocaine in alleviating injection pain for the duration of a two-hour continuous infusion.