Abstract ID: A23
Abstract Title: Undiagnosed Pheochromocytoma in Situ Manifesting in the Immediate Post-Operative Period
Authors: Maalouf D1, Jules-Elysee K2, Liguori G3
Hospital for Special Surgery New York NY USA1, Hospital for Special Surgery New York NY USA2, Hospital for Special Surgery New York NY USA3
Poster Type: Either
ABSTRACT BODY
Introduction
The incidence of pheochromocytomas (pheo) is about one in 1000 to 2000 patients. Hypertension (Htn) the most common sign, is paroxysmal in 20-50% of cases¹. Patients may present for sugery with this tumor undiagnosed. We present a case of pheo that manifested and was diagnosed postoperatively in a patient who underwent bilateral knee replacement (BKR) under combined spinal epidural (CSE) anesthesia.
Case Report
A 62 year old female presented for BKR. Medical history was significant for Htn, and a myocardial infarction (MI) in the setting of tachycardia and Htn after knee arthroscopy one year ago. Cardiac catheterization showed normal coronary arteries.
In the operating room (OR), she underwent bilateral femoral nerve blocks and a CSE with 5 mg of bupivacaine 0.5% and 30 mg mepivacaine 1.5% intrathecally. An arterial line and central venous pressure line were inserted. Propofol infusion was provided for sedation. Her intra-operative course was uneventful: blood pressure (BP) was 110 to 130 mmHg systolic and 50 to 70 mmHg diastolic; heart rate (HR) was 62 to 74 beats/min.
Upon arrival to the recovery room, vital signs were: HR 69 beats /min, BP 125/53 mmHg. Patient controlled epidural analgesia was started. Four hours later, BP and HR increased to 205/95 mmHg and 110 beats/min, respectively. She denied any pain. She was treated with labetalol 20 mg IV, and nitroglycerin infusion was started. ECG showed ST segment elevation in leads V2-V5. Troponin I was 88. Cardiac catheterization again revealed non-obstructive disease. A 24 hour urine sample showed Norepinephrine level to be 576.7µg/L (normal 216 µg/L), Metanephrine and Normetanephrine 6.59 mg/L (normal 2.47 mg/L). On MRI, a large heterogeneous left adrenal gland mass was found. Patient underwent surgical excision of the mass, confirmed to be a pheo.
Discussion
Mortality in patients presenting for surgery with undiagnosed pheo in situ approaches 80%¹. Most of these cases are diagnosed at autopsy since signs and symptoms associated with the disease lack specificity. Catecholamine-induced myocarditis, MI, focal necrosis of cardiac muscle and congestive cardiac failure have been reported².
This patient’s prior MI after her last surgery was probably related to the pheo which was undiagnosed. With this surgery, she did not manifest any signs until 4-5 hours following surgery. Although neuroaxial anesthetic does block the sympathetic nervous system, a hypertensive crisis can still occur due to the response of postsynaptic alpha receptors from high catecholamines levels³. Patients presenting to the OR with undiagnosed pheo pose a challenge to the anesthesiologist. A thorough history should be obtained and a high index of suspicion maintained in patients with refractory perioperative Htn.
References:
1. Sellevold OFM, Reder J, Stenseth R: Undiagnosed pheochromocytoma in the perioperative period. Acta Anaesthesiologica Scandinavia 1985: 29: 474-479.
2. Engelman K: Pheochromocytoma. Clinical Endocrinology and Metabolism 1977: 6: 769.
3. Pullerits J, Ein S, Bolfe JW. Anesthesia for pheochromocytoma. Canadian Journal of Anesthesia 1988: 35: 526-534.
ATTACHED FILES
Reg Anesth Pain Med 2005; 30(3):A23