A nurse is interviewing a pre-operative patient scheduled for a total hip replacement. Which of the following findings would require the nurse to collaborate with the surgeon immediately before sending the patient to the operating room?

A. The client took phenytoin 100mg with a sip of water at 6 a.m.: Phenytoin is generally safe to take before surgery, but the timing should be managed postoperatively. This does not pose an immediate risk to surgery. B. The client took metoprolol 25mg with a sip of water at 6 a.m.: Metoprolol can be taken preoperatively, especially for heart conditions, but the nurse should monitor the patient for any signs of hypotension during or after surgery. C. The client took half their morning dose of insulin at 6 a.m.: Half-dosing insulin is common before surgery to prevent hypoglycemia, but glucose levels should be closely monitored postoperatively to adjust accordingly. D. The client took warfarin 2.5mg with a sip of water at 6 a.m.: Warfarin increases bleeding risk during surgery. The nurse must collaborate with the surgeon to check INR levels and assess whether the surgery should proceed or be delayed due to bleeding risk.