A client has a serum potassium level of 6.5 mEq/L (6.5 mmol/L), a serum creatinine level of 2 mg/dL (176 mcmol/L), and a urine output of 350 mL/day. What is the priority action by the nurse?

Choice A reason: Monitoring intake and output is a necessary part of caring for a client with renal impairment and oliguria (defined as less than 400 mL/day). However, this is a passive observation. It does nothing to address the immediate, life-threatening risk posed by a potassium level of 6.5 mEq/L, which can cause sudden cardiac arrest. Choice B reason: Dietary teaching is an important long-term intervention for managing chronic hyperkalemia and renal insufficiency. However, in an acute situation where the potassium is dangerously elevated (6.5 mEq/L is considered severe hyperkalemia), education is not an appropriate priority. The patient requires immediate medical intervention to shift or remove potassium from the blood. Choice C reason: Redrawing the lab might be considered if hemolyzed blood was suspected, but with a creatinine of 2 mg/dL and low urine output, the potassium level is highly plausible. Delaying treatment to verify a result when the patient is in a high-risk category for renal-induced hyperkalemia is unsafe and delays life-saving care. Choice D reason: Hyperkalemia directly affects the electrical conduction of the heart, potentially leading to peaked T-waves, widened QRS complexes, and ventricular fibrillation. The nurse’s priority is to monitor the cardiac rhythm to detect these lethal changes instantly while preparing for emergency treatments like calcium gluconate, insulin with dextrose, or dialysis.