Table 1

Rules of the first and the second interventions

Rules of the first intervention					Rules of the second intervention
	Target staff	Target location	Rule specifications		Rule specifications
Rule number 1	Physician	All hospital wards and outpatient departments	Prohibits prescription of undiluted KCl
Rule number 2	Physician	Intensive care unit	Based on the guidelines, concentrations up to a maximum 400 mEq/L are allowed only in the following cases16–20: Patients requiring the use of artificial heart-lung machines. Patients requiring percutaneous cardiopulmonary support. Patients undergoing dialysis (dialysis room). Patients in surgery (clinical department of anaesthesiology). Patients admitted to the cardiovascular surgery, critical care medical centre and cardiology departments who require potassium and fluid restriction because of cardiac dysfunction. Patients with haematological malignancies and severe hypokalaemia because of excessive diarrhoea or antifungal drug adverse effects. Based on the guidelines, this may only be administered via central intravenous, infusion device, and the patient must be undergoing continuous cardiac monitoring and frequent testing for serum potassium concentration16–20	Modified Rule number 2	Based on the guidelines, concentrations up to a maximum of 400 mEq/L are allowed for the following cases16–20: When using an artificial heart-lung machine. When using percutaneous cardiopulmonary support. During dialysis. During surgery (clinical department of anaesthesiology). For patients requiring potassium and fluid restriction due to cardiac dysfunction. Patients with haematological malignancies and severe hypokalaemia due to excessive diarrhoea and/or antifungal drug adverse effects. Based on the guidelines, this may only be administered via central intravenous, infusion device, and for patients undergoing continuous cardiac monitoring and frequent testing for serum potassium concentration16–20
Rule number 3	Physician	General ward and outpatient departments	Dilute to a concentration of less than 40 mEq/L, according to the attached Japanese document	Modified Rule number 3	Dilute to a concentration of less than 40 mEq/L, according to the attached Japanese document. (Additional exclusion criteria) When physicians and pharmacists agree that a dose exceeding 40 mEq/L KCl is necessary, it is allowed
Rule number 4	Pharmacist	All wards and outpatient departments	The pharmacist queries any physician who prescribes a dose of KCl that deviates from any of the first three rules. When the pharmacist delivers KCl, they provide a warning document regarding the medication to the nurse
Rule number 5	Nurse	General ward and outpatient departments	The nurse queries the physician if there is a prescription at a concentration exceeding 40 mEq/L

KCl, potassium chloride.