The nurse is reviewing laboratory results for a patient scheduled for a cholecystectomy. Which result is most important for the nurse to report to the surgeon?

Blood glucose level of 90 mg/dL (5 mmol/L).

Serum creatinine level of 5 mg/dL (442 µmol/L).

Hemoglobin level of 13 g/dL (130 g/L).

Potassium level of 4 mEq/L (4 mmol/L).