Patient tolerance to intravenous potassium chloride with and without lidocaine

Hypokalemia is a common electrolyte abnormality. Intravenous repletion therapy with potassium chloride (KCl) in concentrations greater than 80-100 mEq/L is not recommended due to patient intolerance. Since this guideline at times may be clinically impractical, this study was designed to examine use of peripheral vein infusions of high concentration KCl therapy. Tolerance to KCl 20 mEq/65 ml iv with and without lidocaine 50 mg was evaluated in 18 hypokalemic subjects in a randomized, placebo-controlled, double-blind study. Subjective and objective assessments of adverse effects were determined throughout the infusion period. Pain was assessed by both verbal descriptor and visual analog scales and correlated significantly following infusion of KCl with or without lidocaine. Multivariant analysis demonstrated differences in pain perception between solutions, with significantly less pain following KCl with lidocaine versus KCl infusions. Transient adverse effects occurred in both groups, but the incidence was not statistically different. Use of concentrated iv KCl infusions may benefit hypokalemic patients with hypervolemia and/or severe potassium deficits. Addition of lidocaine clearly improves patient tolerance to intravenous KCl replacement.