1. with aortic regurgitation
Anesthetic management of a robotic laproscopic adrenalectomy for pheochromocytoma
with aortic regurgitation
Rakhi Pal , MD ; John Jerabek DO ; Anesthesiology Institute , Cleveland Clinic , Ohio
The intraoperative goals for Pheochromocytoma :
• Avoid drugs or maneuvers which produce a catecholamine surge
• Maintain cardiovascular stability with short acting drugs
• Maintain normovolaemia and hemodynamics after tumor resection
Intra operative Catecholamine surge :
• Induction and intubation
• Surgical incision
•Pneumoperitoneum during laparoscopic approach
• Abdominal exploration and tumor manipulation
• Ligation of venous drainage
Factors to avoid ( which releases catecholamines):
stress, anxiety, pain, hypoxia, hypercarbia. Endotracheal intubation
Monitoring and vascular access
• ECG (CM5)
• Pulse oximeter
• EtCO2
• Temperature probe
Invasive blood pressure – Arterial line –pre induction CVP monitoring
• Cardiac output monitoring in cardiomyopathy (Pulmonary artery catheter, TOE)
• Large bore peripheral venous access
• Urinary catheter
Choice of agents:
Avoid medications that can stimulate the sympathetic nervous system.
Caution should be exercised when using histamine releasing drugs (Atracurium, Morphine).
Succenylcholine can produce a catecholamine surge by virtue of muscle fasciculation and drugs such as metoclopramide, ephedrine, and chlorpromazine can also produce hypertensive responses.
Drugs considered safe include: Propofol, Etomidate, Fentanyl, Alfentanil, Remifentanil, Benzodiazepines,Vecuronium, Rocuronium, Isoflurane, Sevoflurane.
Blood glucose should be closely monitored (hypoglycaemia is common after tumor removal)
Normothermia should be maintained with the use of forced air warming devices.
Catecholamine withdrawal following venous ligation
Factors responsible for the refractory hypotension following ligation of the venous drainage of the tumor:
A sudden drop in the catecholamine concentration, the residual α blockade from phenoxybenzamine, down regulation of adrenoceptors, suppression of the normal contralateral adrenal gland from excessive catecholamines, myocardial dysfunction and hypovolemia from blood and fluid loss
Introduction
A 38-yr-old lady with known past medical history of HTN and aortic regurgitation and recently confirmed diagnosis of pheochromocytoma with left adrenal mass on magnetic resonance imaging. The patient was treated with alpha- followed by beta-blockade with phenoxybenzamine and metoprolol. The goal of perioperative management of pheochromocytoma was to prevent hypertensive crisis but in this case it was challenging in presence of aortic valve regurgitation.
From aortic regurgitation point of view goal was to maintain HR to minimizes regurgitant flow, although optimal HR is controversial) and reduce afterload to encourage forward flow. Also preload must be maintained as these patients are dependent on it, keep in mind that excessive LV volume can lead to pulmonary edema. Afterload reduction with nitroprusside requires full hemodynamic monitoring. Ephedrine is the preferred first-line vasopressor, although small doses of phenylephrine (25–50 ucg) can be attempted.
We describe the successful peri-operative management of pheochromocytoma in the setting of moderate aortic valve regurgitation. Intra operative course was uneventful except for brief episode of high SBP (more than 200 mmHg) which was controlled with nitroglycerine. So balanced approach towards maintaining afterload, HR BP was our goal. A preventative measure involved volume loading before tumor ligation and fluid boluses should be tried before initiating vasoactive medications.
and Objectives.
Post operative management
These patients, ideally, are managed postoperatively in an ITU/HDU. Anticipated problems include refractory hypotension (which might require large volumes of fluid and vasopressor therapy),and hypoglycemia due to excess insulin release and inadequate glycogenolysis.
Consider steroid supplementation if bilateral adrenalectomy is carried out or if hypoadrenalism is suspected.
The majority of patients are restored to normotension although plasma catecholamine levels may still be elevated due to their slow release from the nerve terminals. Sustained hypertension after surgery could be due to residual tumor, renal ischemia or underlying essential hypertension.
α-blockade
Selective α1-blockers (Prazosin and doxazosin)
Shorter duration of action
Easier dose adjustment
↓ postop hypotension
↓reflex tachycardia presynaptic α-receptors are not blocked
Roizens criteria for adequate α-blockade
Arterial BP < 160/95 mm Hg in the last 48 hrs prior to surgery. Recommended to measure in stressful environment
Mild orthostatic hypotension indicates optimal  adrenergic blockade but not < 80/45.
ECG- free of ST changes for > 2 wks,
Ventricular ectopic < 1 over 5 min
B blockade
If tachycardia persists then a beta blocker should be used.
β blockade should only be administered if the pt is concurrently taking an α blocker.
Unopposed α-mediated vasoconstriction has the potential to place the patient in CHF or can result cardiac arrest.
Labetalol and atenolol
Refernces :
Yao, F. F., Fontes, M. L., Malhotra, V. (2008). Anesthesiology: problem oriented patient management (6th ed.). Philadelphia: Lippincott Williams & Wilkins
Stoetling, R. K., Dierdorf, S. F., (2002). Anesthesia and Co-existing Disease (4th ed.). Philadelphia: Churchill Livingstone