A 45-year-old male undergoing treatment for diffuse large B-cell lymphoma at a day care center develops oliguria 24 hours post-chemotherapy. Despite aggressive hydration, rasburicase, and allopurinol, the patient remains oliguric. Laboratory results reveal a serum potassium of 7.2 mEq/L, serum phosphate of 8.5 mg/dL, serum calcium of 6.0 mg/dL, serum uric acid of 20 mg/dL, and a creatinine level of 4.5 mg/dL. A critical care referral is made after the patient exhibits stridor and generalized muscle cramps. The 12-lead ECG shows a QTc interval of 550 msec.
Right Answer: A. Intravenous calcium gluconate
Explanation: The patient with tumor lysis syndrome (TLS) is showing signs of severe hypocalcemia, including laryngospasm and prolonged QT interval, which may result in life-threatening cardiac arrhythmias. Administering intravenous calcium gluconate (Option A) is the best intervention to stabilize the cardiac membrane and address hypocalcemia-related complications. While sodium bicarbonate (Option B) may help with metabolic acidosis, it won’t address the immediate risk of cardiac arrhythmias caused by hypocalcemia. Magnesium sulfate (Option C) is used to treat torsades de pointes, another arrhythmia, but it’s not the primary treatment for hypocalcemia. Increasing the dose of rasburicase (Option D) may help reduce uric acid levels, but it does not address the immediate concern of hypocalcemia and cardiac instability.
Wrong Answer:B. Intravenous sodium bicarbonate
Wrong Answer:C. Administer magnesium sulfate
Wrong Answer: D. Increase the dose of rasburicase
