Before intravenous administration of potassium chloride, which parameter should be measured?

• A. Blood pressure
• B. Respiratory rate
• C. Urine output
• D. Pulse deficit

Answer: (C)

Potassium chloride given IV must be excreted by the kidneys, so the key concern is whether the patient has adequate renal function to handle the extra potassium. Measuring urine output directly assesses this ability; low or absent urine output suggests impaired clearance and a higher risk of dangerous potassium buildup, so the infusion should be delayed or adjusted. While other vital signs matter for overall status, they do not specifically indicate the body’s capacity to eliminate potassium.