Nitroprusside Therapy for a Patient With a Pheochromocytoma

Abstract

A 32-year-old woman was transferred to the George Washington University Hospital Intensive Care Unit from another hospital, with uncontrolled hypertension six hours after cesarean section. The patient had a history of labile hypertension and di et \ x=req-\ controlled diabetes. She was hypertensive during her first pregnancy, miscarrying at six months.During the current pregnancy, blood pressure became 140/90 mm Hg, and occasional flushing, pedal edema, and proteinuria occurred. At 32 weeks, she was admitted with a blood pressure of 220/140 mm Hg, unchanged by diazepam and bed rest. Despite methyldopa therapy, 500 mg every six hours, blood pressure was 180/130 mm Hg. An intravenous drip of hydralazine hydrochloride, 200 mg, and cryptenamine acetate, 10 mg, produced headache, flushing, and chest pain. Therapy was subsequently discontinued. When blood pressure reached 240/190 mm Hg, she received 5 g of magne¬ sium sulfate, intravenously, and underwent successful cesarean delivery of a 6.6 kg boy.The blood pressure remained 160/130 mm Hg and she was transferred to George Washington Hospital.On physical examination, she was per¬ spiring, flushed, and lethargic. Blood pres¬ sure was 150/130 mm Hg and pulse was regular at 160 beats per minute. Pupils were widely dilated and reactive, and fundi showed bilateral papilledema with hem¬ orrhages and exudates. There was a summation gallop and recent abdominal surgical scar. The results of the rest of the examination were normal. Admission laboratory levels included hematocrit, 47.4%; leukocyte count, 18,200/ cu mm; normal levels of serum electrolytes, creatinine, and blood glucose; and BUN, 24 mg/dl. Urinalysis showed a specific gravity of 1.022, proteinuria (4 + ), and 5 WBCs and 10 RBCs per high-powered microscopic field. A chest roentgenogram showed clear lung fields, and an ECG showed a sinus tachycardia at a rate of 160 beats per minute, with left ventricular strain.On admission a sodium nitroprusside drip was started at 0.6 Mg/kg/min. Blood pres¬ sure decreased to 120/110 mm Hg during a 30-minute period and then stabilized. Four hours later, methyldopa therapy, 250 mg every six hours, was begun, and the patient was vigorously hydrated. After 12 hours, nitroprusside therapy was stopped and blood pressure was 120/100 mm Hg. Magne¬ sium sulfate, 1 g intravenously hourly, was given to prevent eclamptic seizures. During the next 36 hours, blood pressure remained 120/90 mm Hg, and both methyldopa and magnesium therapies were discontinued. After hydration, the hematocrit reading was 37%, and the pulse rate was 125 beats per minute.She was transferred to the obstetrics service and remained normotensive until the fourth hospital day, when the blood pressure became 160/110 mm Hg. Hyper¬ tension was unresponsive to methyldopa, 250 mg every six hours; phénobarbital, 90 mg twice daily; and hydrochlorthiazide, 50 mg daily. On the sixth hospital day, pulmonary edema ensued, necessitating transfer to the Intensive Care Unit for treatment with digoxin, furosemide, mor¬ phine sulfate, a...

Perioperative management of pheocromocytoma/ paraganglioma: a comprehensive review

“…The former can be managed with analgesia and adequate anesthetic depth, while the latter must be addressed with the use of rapid vasodilator infusions, requiring the availability in the operating room of a potent vasoactive agent already prepared. In our setting, the most frequently used agents are nitric oxide modulators (nitroprusside or nitroglycerine) (71). However, other options include β-blockers like labetalol or esmolol (preferred in adrenalin-secreting tumors) (72), calcium channel blockers like nicardipine (always remembering its long half-life), or even magnesium sulphate which inhibits catecholamine release because of its direct action on the catecholamine receptor and plays an important role particularly in cases of concomitant arrhythmias, at a dose of 50 mg/kg followed by infusion of 1 to 2 g/h (73).…”

Hypertension following coronary artery bypass surgery. Role of preoperative propranolol therapy.

“…12 Although it is equally true that other agents such as sodium nitroprusside 4 ' 7 ' 10> ll and converting enzyme inhibitor 1 ' are also capable of decreasing blood pressure in this situation, this does not negate the role of the sympathetic system. Sodium nitroprusside is known to be effective even in patients with refractory hypertension resulting from pheochromocytoma, 40 and converting enzyme inhibitor has many actions other than blockade of the reninangiotensin system. 41 It must be emphasized that our findings were obtained in a relatively small group of patients and that the importance of these observations can only be confirmed by further studies.…”