Objectives Serious adverse effects, including arrhythmia and cardiac arrest, result from rapid intravenous high concentration of potassium chloride (KCl). We aimed to eliminate prescription of undiluted KCl and encourage dilution of KCl to 400 mEq/L and 40 mEq/L in the intensive care units (ICUs) and general and outpatient departments, respectively.

Methods Before the first intervention, we collected data regarding high-concentration KCl and interviewed representatives of physicians prescribing high-concentration KCl. Based on the guidelines in other countries on safely used concentrations of KCl (400 mEq/L), we negotiated with physicians to dilute KCl below 400 mEq/L. In the first intervention, we made rules based on surveys above. In the second intervention, we revised the rules based on opinions from physicians and pharmacists and investigated the change in the number of prescriptions of KCl concentration in each department. Continuing efforts with the safety manager ensured compliance of the rules by physicians and nurses in all departments.

Results After the first and second interventions, prescriptions for undiluted KCl in ICUs and general wards were eliminated (median=0). Prescriptions for <400 mEq/L KCl increased to 110 (median) after the first intervention and to 137 (median) after the second. In the general ward, 7 months after the first intervention, prescriptions for <400 mEq/L KCl had not increased. Compliance with our rules was high, and more than 72% of physicians and nurses were aware of the rules.

Conclusions The rules for administration of high-dose KCl successfully eliminated prescription of undiluted KCl, which was maintained using two plan-do-study-act cycles. Our intervention process could be useful in countries where prediluted formulations are unavailable or where prescriptions are not matched and undiluted ampules are used.