A 51-year-old man with a history of a heart murmur since childhood presented with periodic palpitations, headaches, flushing, nausea and vomiting. Transthoracic echocardiography (TTE) revealed severe aortic stenosis with an aortic valve area of 0.8 cm2 and a mean gradient of 48 mmHg as well as mild-moderate aortic regurgitation. During further workup, the patient was also found to have a functional 4 × 4 cm left adrenal pheochromocytoma with elevated plasma metanephrine and normetanephrine of 4.88 (nl 0-0.49) and 4.44 (nl 0-0.89) nmol/L respectively. Outpatient management of his pheochromocytoma included terazosin 2 mg twice daily, bisoprolol 10 mg daily, losartan 50 mg twice daily, and amlodipine 2.5 mg twice daily. Treatment with α-blockade was limited due to his severe aortic stenosis, as the patient experienced syncopal episodes with increased doses of terazosin. A staged surgical approach was planned: surgical AVR followed by adrenalectomy the next day.
The patient was brought to the operating room where femoral arterial and venous access was obtained under sedation using dexmedetomidine and midazolam. Anesthesia was induced with fentanyl, midazolam, propofol, and rocuronium. Intubation was performed with 4% lidocaine topicalization and video laryngoscopy to minimize sympathetic stimulation. Intraoperative analgesia was augmented with a high dose sufentanil infusion and incremental boluses as needed. A clevidipine infusion and incremental clevidipine boluses were used to control very labile mean arterial pressures (MAP) up to 150 mmHg. Cannulation and initiation of cardiopulmonary bypass (CPB) were otherwise uneventful.
While on CPB, significant hypertension required clevidipine and nitroglycerin (NTG) infusions. Following placement of a 23 mm St. Jude mechanical valve in the aortic position (mean gradient of 10 mmHg), the patient was weaned from CPB with normal biventricular function. The immediate post-CPB period was marked by profound hemodynamic lability (MAP < 50 to > 150 mmHg) (Fig. 1). Severe hypertension required large boluses of NTG and clevidipine; and severe hypotension was treated with vasopressin. Of note, the patient was hyperglycemic throughout the case with glucose levels exceeding 500 mg/dL, requiring a high dose insulin infusion.
After transfer to the intensive care unit (ICU), in an attempt to control hemodynamics and blunt any sympathetic discharges, he was deeply sedated with high doses of midazolam (8 mg/hr), hydromorphone (8 mg/hr) and dexmedetomidine (1.7 mcg/kg/min). He was also paralyzed with a cisatracurium infusion to assist with ventilator synchrony. Despite these interventions, dramatic blood pressure swings continued, reaching MAP of 150–175 mmHg and requiring maximum doses of clevidipine, sodium nitroprusside, esmolol and fenoldopam, followed by extreme hypotension with MAPs 35–40 mmHg. These cyclical events recurred more than a dozen times despite continuous bedside physician attention and best attempts at drug titration. The patient also developed high fevers to 39.4 °C and severe hyperglycemia requiring a high dose insulin infusion with additional boluses of insulin for glucose levels exceeding 300 mg/dl. During this time, the patient's wife admitted that the patient was drinking alcohol heavily up until the day before surgery. This raised our concern that acute alcohol withdrawal was contributing to his labile state.
The morning after his AVR, the patient remained very unstable with extremely labile blood pressures and began to develop runs of non-sustained ventricular tachycardia for which he was started on amiodarone. Because of the high likelihood of significant morbidity/mortality if the pheochromocytoma was not removed, the patient was taken urgently to the operating room for open adrenalectomy.
Deep sedation and analgesia were maintained with the addition of low dose sevoflurane and a high dose remifentanil infusion. Intra-operatively, the patient continued to have labile hemodynamics unrelated to surgical stimulation, with MAPs ranging from 40 to 175 mmHg (Fig. 2). Escalating bolus doses of nitroprusside and nitroglycerin were given with minimal effect during these acute hypertensive episodes. During periods of hypotension, vasopressin boluses were used, also with minimal effect. It was noted that during episodes of extreme hypertension, the patient exhibited signs of acute right ventricular (RV) failure manifested by acute rises in central venous pressure (CVP) up to 30 mmHg and hypoxemia as evidenced by reduced arterial oxygen saturation (SaO2) to 85–90%, which resolved with decreased blood pressure.
After the pheochromocytoma was isolated from its vascular supply, immediate cardiogenic and vasoplegic shock developed with MAP ranging from 35–45 mmHg and cardiac output (CO) 3.4 L/min. An epinephrine infusion was initiated to support inotropy and vascular tone. Sedation was appropriately decreased. Vasopressin boluses and a 1 mg/kg dose of methylene blue were administered with marginal effect. Subsequently, an infusion of recombinant angiotensin II was started and rapidly up titrated to a maximum dose (80 ng/kg/min) with improvement of MAPs to 50–60 mmHg. Given the native heart rate of 65 bpm was inadequate to support cardiac output and MAP, epicardial pacing was initiated in DDD mode at 100 bpm. This intervention increased the MAP to greater than 60 mmHg and CO to 4.5 L/min (Fig. 2). Shortly after tumor removal, glucose levels dropped precipitously, so the insulin drip was stopped and dextrose was administered.
The patient was transported back to the ICU, where his postoperative course was complicated by continued cardiogenic and vasoplegic shock, RV failure, ventricular tachycardia and hypoxic respiratory failure with pulmonary edema. He continued on amiodarone, epinephrine and angiotensin II infusions. A milrinone infusion and inhaled epoprostenol was added for RV support with significant improvement in both oxygenation and CO (> 6 L/min). He remained sedated with dexmedetomidine, hydromorphone and midazolam. The patient was weaned off angiotensin II six hours postoperatively, followed by a deep sedation taper the following day.
Postoperative recovery was hindered by severe agitation and delirium with hallucinations, but on postoperative day (POD) 6 he was extubated and weaned off all inotropic and vasopressor support. His subsequent hospital course was marked by fungal infection (workup negative for endocarditis), methicillin-resistant Staphylococcus aureus (MRSA) pneumonia, atrial fibrillation, and respiratory failure requiring a period of intubation. His delirium finally resolved six weeks after surgery, and he was discharged home on POD 38.