The use of lidocaine to reduce the pain induced by potassium chloride infusion

The effect of lidocaine on the pain induced by the intravenous infusion of potassium chloride (KCl) was evaluated. Six volunteer subjects received 10 mEq of KCl in 50 ml of 5% dextrose in water in one arm, and in the other arm received the same solution with 10 mg of lidocaine added. Each solution was infused over 1 hour, and the subjects and investigatorwere blinded. Subjects: rated pain on a seven-point scale (1 is mild, 7 is severe). Pain was significantly less severe with the solutions containing lidocaine. Mean values were 3.17 with lidocaine and 6.17 without lidocaine (p<0.01). Lidocaine in a dose of 10 mg added directly to the infusion solution significantly reduced the pain induced by the I.V. bolus infusion of 10 mEq of potassium chloride.