Two hours before a client's scheduled surgery, the nurse is completing the preoperative checklist. Which information requires immediate action by the nurse? Reference Range: Potassium (3.5 to 5 mEq/L (3.5 to 5 mmol/L)]

Rationale: A. Preoperative chest x-ray report is not available: While the chest x-ray may be important for baseline assessment, it typically does not pose an immediate risk that would delay surgery unless specifically required for anesthesia clearance. B. Surgical consent form is not signed: Obtaining a signed consent is essential for legal and ethical reasons, but it can usually be addressed quickly without delaying immediate safety interventions. C. Preoperative serum potassium level is 2.8 mEq/L (2.8 mmol/L): Hypokalemia increases the risk of life-threatening cardiac arrhythmias during surgery and anesthesia. Correcting potassium and notifying the healthcare provider takes immediate priority to prevent perioperative complications. D. Client's pulse oximeter reading is 96%: This oxygen saturation is within an acceptable range and does not require urgent intervention before surgery.