Intraoperative Management of Pheochromocytoma
By: Karen Garcia, BSN
University of Pennsylvania
Anticipated date of graduation: May 2015
Email address: garciak@nursing.upenn.edu
Keywords: Pheochromocytoma, anesthetic management, perioperative, intraoperative
Pheochromocytoma is a tumor that predominantly secretes norepinephrine. Clinical
manifestations include hypertension (HTN), diaphoresis, headaches, tremors, and palpitations. A
pheochromocytoma tumor may be removed through surgical resection. It is a rare, highly
vascular, neuroendocrine tumor, originating in the chromafin cells, found in the adrenal medulla
90% of the time or in an extra-adrenal location. Patients with pheochromocytomas have
paroxysmal signs and symptoms of sympathetic nervous system hyperactivity including
diaphoresis, tachycardia, headache, severe HTN, palpitations, anxiety, elevated blood glucose
levels, and cardiomyopathy. If these tumors are not removed, patients can die from congestive
heart failure, myocardial infarction, and intracerebral hemorrhage.
Case Report:
A 58 year old female presented with a pheochromocytoma on the adrenals that needed to be
surgically removed. She was 162 cm and approximately 92 kilograms. Her medical history
consisted of HTN, type 2 diabetes, high cholesterol, and breast cancer. Her surgical history
consisted of a lumbar disc surgery, cholycystectomy, and breast lumpectomy; none of which
were associated with anesthetic complications. Her medications included diltiazem 240 mg,
hydrochlorothiazide 25 mg, lisinopril 40 mg, metformin 1000 mg, phenoxybenzamine 80 mg,
insulin aspart PRN, and lantus 40 units at bedtime.
A preoperative airway assessment was completed and revealed a Mallampati classification of II,
a thyromental distance greater than 6 cm, an estimated oral opening of 3 cm, full atlantooccipital range of motion, and partial dentures, which were removed preoperatively.
Premedication of intravenous midazolam 2 mg was given prior to induction of anesthesia. In the
operating room, standard ASA monitors were applied and preoxygenation with 100% via face
mask at 10 L/min of oxygen flow was provided for approximately 11 minutes. General
anesthesia was induced with intravenous lidocaine 100 mg, propofol 200 mg, and fentanyl 150
mcg. Once adequate mask ventilation was confirmed successfully without any airway adjuncts,
intravenous rocuronium 50 mg was given. The patient was mask ventilated for approximately 3
minutes. A direct laryngoscopy was performed with a Mac 3 blade and a Grade 1 full view of
glottis obtained. A 7.0 mm endotracheal tube was advanced through the glottis. Positive bilateral
breath sounds and end tidal carbon dioxide (ETCO2) was confirmed with the endotracheal tube
secured at 20 cm at the lip using tape. After successful intubation, a left radial arterial line was
obtained as well as a second large bore intravenous access.
General anesthesia was maintained with sevoflurane 2% inspired concentration in a mixture of
oxygen 1 L/min and air 1 L/min. The patient was placed on pressure controlled mechanical
ventilation. Throughout the case, an additional intravenous fentanyl 250 mcg, hydromorphone 1
mg, and ondansetron 4 mg was given. For blood pressure management intraoperatively, a total of
intravenous phenylephrine 1300 mcg was given as well as a total of intravenous nitroglycerin
100 mcg. The patient also received intravenous regular insulin 5 units for a blood glucose of 219.
Intravenous crystalloids given measured 3400 mL along with 500 mL of 5% albumin. A total of
approximately 300 mL of urine output was measured via foley catheter.
At the conclusion of the case, neuromuscular blockade was reversed by intravenous neostigmine
4 mg and glycopyrolate 0.6 mg. Sevoflurane was turned off and oxygen flows were increased to
10 L/min of 100% oxygen. The patient began spontaneous respirations with inadequate tidal
volumes of less than 100 mL and did not follow commands. At this time, the decision was made
to keep the patient intubated to the post anesthesia care unit (PACU). Once in the PACU, a Tpiece was adjusted onto the endotracheal tube. The endotracheal tube was later removed in the
PACU once the patient was more awake with adequate tidal volumes.
Discussion
Pheochromocytoma tumors are typically found on the adrenals and may be removed through
surgical resection. Pheochromocytoma tumors secrete excessive catecholamines – usually 80%
norepinephrine and 20% epinephrine.1 The pathway for catecholamines begins with tyrosine
which is then converted to dopa by tyrosine hydroxylase. Dopa is converted to dopamine, then
norepinephrine, then ultimately into epinephrine. Catecholamine secretion may be stimulated by
tumor manipulation, postural changes, exertion, anxiety, trauma, pain, and use of
sympathomimetics, phenothiazines, reglan, histamine, or glucagon.1
Anesthetic management for a pheochromocytoma is challenging due to fluctuations in blood
pressure throughout the surgical procedure. Although preoperative alpha adrenergic blockade
decreases perioperative mortality, approximately 25% of patients continue to present with
hypertensive events intraoperatively.2 Pheochromocytoma surgery for large lesions are
challenging because of the excessive secretion of catecholamines, the extensive vascularization
of the tumor, and the tumor’s adhesions to adjacent structures, such as major blood vessels.3
Pheochromocytoma perioperative management includes a preoperative catecholamine blockade,
intraoperative management of acute catecholamine excess before tumor resection, and an
intraoperative intervention for acute catecholamine deficiency after tumor resection.4
Proper preoperative management of the pheochromocytoma patient is vital to successful
perioperative care. Alpha adrenergic blockade medications, such as phenoxybenzamine and
phentolamine, are optimal pre-anesthetic management essentials to decreasing perioperative
mortality.5 Alpha adrenergic blockade inhibits the deleterious effects of vasoconstriction, which
is why preoperative alpha adrenergic blockade is detrimental to perioperative management of a
pheochromocytoma.5 In this particular pheochromocytoma case, preoperative alpha adrenergic
blockade was administered successfully. This made for easier perioperative management as well
as fewer fluctuations in blood pressure throughout the case. In addition to alpha adrenergic
blockade, beta adrenergic receptor blockade may be introduced preoperatively for control of
tachycardia, hypertension, and catecholamine-induced supraventricular dysrhythmias.1 Beta
adrenergic blockade should not be introduced until alpha adrenergic blockade is successfully
established. Beta adrenergic mediated vasodilation in skeletal muscle without prior alpha
adrenergic blockade can cause an exacerbation in hypertension in this patient population.1 In this
particular case, the patient’s heart rate and blood pressure was successfully managed
preoperatively with the sole use of an alpha adrenergic blockade from phenoxybenzamine.
Invasive blood pressure monitoring perioperatively is highly recommended along with
hemodynamic management during surgical stimuli, such as induction, intubation, and tumor
manipulation. It is important to note that the use of intravenous magnesium sulfate, clevidipine,
and vasopressin in more recent studies. Magnesium is considered to have a strong indication in
pheochromocytoma management due to its stabilizing effects on cardiac electrical conduction. 4
Magnesium provides a catecholamine blockade and protects against life threatening cardiac
arrhythmias.4 In addition, clevidipine is discussed as an intravenous calcium channel blocker that
may allow for safe, rapid, and effective arterial vasodilation for the control of hypertension. The
half life of intravenous clevidipine is about one minute due to metabolism by plasma esterases.
Intravenous clevidipine was shown to be more effective than intravenous nitroglycerin and
sodium nitroprusside at maintaining blood pressure within a narrowly defined range. 4
Vasopressin is a third medication that is being discussed for pheochromocytoma management in
recent studies. This medication is a naturally occurring nonapeptide hormone that is produced in
the hypothalamus and stored in the posterior pituitary.4 Vasopressin plays a major role in
regulation of extracellular fluid volume by increasing water reabsorption through the collecting
ducts of the kidneys. It was compared with catecholamines and produces less coronary,
pulmonary, and cerebral vasoconstriction.4 Intravenous vasopressin may have been a more ideal
choice for successful treatment of hypotension prior to tumor resection, as opposed to
intravenous phenylephrine. In addition, treatment of hypertension presenting post tumor
resection could have been treated with intravenous clevidipine, as opposed to intravenous
nitroglycerin.
Post operative management should include possible admission to the intensive care unit due to
blood pressure instabilities as well as hypoglycemia.6 Hypertension and increased plasma levels
of catecholamines are present in 50% of post operative pheochromocytoma cases.5 Causes of
postoperative hypertension include fluid shifts, pain, hypoxia, hypercapnia, autonomic
instability, urinary retention, or residual tumor.1 Several days may be required for postoperative
catecholamine levels to decrease to normal in the postoperative pheochromocytoma patient.
Normal blood pressure levels usually return within 14 days postsurgery in 75% of patients.1
Hypoglycemia may also pose as a post operative challenge due to decreased glycogen levels in
this patient population. Adrenergic stimulation causes an increase in glycogenolysis and lipolysis
which directly affects glycogen levels, therefore causing hypoglycemia.5
If the case was to be done differently, incorporation of recent studies that integrate magnesium,
clevidipine, and vasopressin would have been useful. Instead of intravenous phenylephrine
boluses after tumor resection, it may have been advantageous to consider intravenous
vasopressin as a continuous infusion until the patient was extubated. Intravenous clevidipine
would also have been useful as opposed to the use of intravenous nitroglycerin when considering
treatment for hypertension perioperatively.
References:
1. Karlet M, Fort DN. The endocrine system and anesthesia. In Nagelhout JJ, Plaus KL, eds.
Nurse Anesthesia. 5th ed. St.Louis:Elsevier;2014:867-871.
2. Hariskov S, Schuman R. Intraoeprative management of patients with incidental
catecholamine producing tumors: a literature review and analysis. J Anaesthesiol Clin
Pharmacol. 2013;29(1):41-46. doi: 10.4103/0970-9185.105793. Accessed July 30, 2014.
3. Conzo G, Musella M, Corcione F, et al. Laparoscopic adrenalectomy, a safe procedure for
pheochromocytoma: a retrospective review of clinical series. Int J Surg. 2013;11(2):152-156.
doi: 10.1016/j.ijsu. Accessed July 30, 2014.
4. Lord M, Augoustides J. Perioperative management of pheochromocytoma: focus on
magnesium, clevidipine, and vasopressin. J Cardiothorac Vasc Anesth. 2013;26(3):526-531.
doi: 10.1053/j.jvca.2012.01.002. Accessed July 30, 2014.
5. Kim D, Matsiu C, Gozzani J, Mathias L. Pheochromocytoma anesthestic management. Open
Journal of Anesthesiology. 2013(3):152-155. doi: 10.4236/ojanes.2013.33035. Accessed July
30, 2014.
6. Singh-Bajwa S, Bajwa S. Implications and considerations during pheochromocytoma
resection: a challenge to the anesthesiologist. Indian J Endocrinol Metab.
2011;15(suppl4):337-344. doi: 10.4103/2230-8210.86977. Accessed July 30, 2014.