This document provides information about pheochromocytoma and considerations for anesthesia. It begins with definitions and descriptions of pheochromocytoma as a catecholamine producing tumor. It then discusses signs and symptoms, methods of diagnosis including biochemical tests and imaging, and goals for anesthesia including hemodynamic stability. The document provides detailed guidance on pre-induction, induction, and post-operative management strategies to reduce risks such as hypertensive crises during tumor manipulation and hypotension after resection. Key elements include preoperative alpha-adrenergic blockade, careful induction to avoid sympathetic stimulation, invasive monitoring, and vasoactive drugs to control blood pressure fluctuations intraoperatively and postoperatively.

1. PHEOCHROMOCYTOMA
ANESTHESIA
CONSIDERATION
DR SARDAR SAUD ABBAS
DIPLOMA IN ANESTHESIA (HMC), 2ND YEAR FCPS TRAINIEE (KTH)

2. CONTENTS
 Definition
 Quick anatomy and physiology review
 Signs and Symptoms
 How to diagnose the disease
 Anesthesia goals
 Pre Induction
 Anesthesia Induction
 What to expect post operatively

3. DEFINITION
• Def: It is a catecholamine producing tumor derived from chromofin cells. It is also called a
neuroendocrine tumor of medulla of adrenal gland.
• These tumor are clearly important to anesthetist because 25%-50% deaths occur of patients of
pheochromocytoma during induction of anesthesia.
• This tumor secretes massive amount of adrenaline and noradrenaline.
• This tumor is 95% in abdomen in which 90% it is present in renal medulla.
• These tumor can also occur in right atrium, the spleen, the broad ligament of ovary or at bifurcation of
aorta.

5. CATECHOLAMINE PRODUCING TUMOR
 Large pheochromocytoma : more metabolites (metabolizes in tumor before secretion)
 Small pheochromocytoma: more catecholamine
 Sporadic pheochromocytoma: norepi > epi
 Familial pheochromocytoma: epi > norepi
 Malignant Pheochromocytoma: Dopamine, HVA
 Neuroblastoma : Dopamine, HVA
 Paraganglionic : norepi

6. PHEOCHROMOCYTOMA RULE OF 10
 10% extra adrenal (closer to 15%)
 10% occurs in children
 10% familial
 10% bilateral (closer to 20%)
 10% recurrence
 10% malignant
 10% discovered incidentally

7. ANATOMY
 Situated at superior medial aspect of the kidney
 4 gram in weight. But L>R
 Right adrenal gland is situated near
IVC beneath diaphragm and liver
 Left is situated between kidney
aorta near pancreatic tail and splenic artery
 Supplied by Superior, middle and inferior
Supra renal artery
 And suprarenal vein

8. PHYSIOLOGY

9. ADRENERGIC RECEPTORS
• Alpha Adrenergic Receptor:
a1: Vasoconstriction, intestinal relaxation, uterine contraction, pupillary dilation
a2: Decrease presynaptic NE, platelet aggregation, vasoconstriction, decrease insulin secretion
• Beta Adrenergic Receptor:
b1: Increase heart rate and contractility, increase lipolysis, increase renin secretion
b2: Vasodilation, bronchodilation,
b3: Increase lipolysis

10. SIGNS AND SYMPTOMS
• The classic triad:
1) Headache
2) Sweating
3) Palpitation
• 5 P’s of Pheochromocytoma
1) Pressure (hypertension)
2) Pain (headache)
3) Perspiration (sweating)
4) Palpitation
5) Pallor

11. CARDIAC MANIFESTATION
 Sinus tachycardia, SVT, Ventricular ectopic
 Catecholamine induced myocardial oxygen consumption, coronary vasospasm
 Angina
 Hypertrophic cardiomyopathy
 Dilated cardiomyopathy
 CCF with myocarditis
 Orthostatic hypotension is due to volume depletion due to prolong catecholamine, loss of postural
reflexes

12. NEUROLOGIC MANIFESTATION
 Hypertensive encephalopathy (altered mental status, seizures)
 Stroke – due to cerebral infarction
 Intracerebral bleed

13. HOW TO DIAGNOSE A DISEASE
• 1) Biochemically
• 2) Imaging

14. BIOCHEMICALLY
 Traditionally
24 hours urinary collection of catecholamine and vanillylmandelic acid
 Catecholamine short half life makes it difficult so in modern technique we measure
 Metanephrine and normetanephine (break down products of epinephrine and norepinephrine
respectively)
 Plasma tests are more sensitive but urinary tests are more specific
 Dopamine secreting tumors can be identified by measuring plasma or urinary Dopamine and
homovanillic acid

15. IMAGING
 After positive biochemical test, first line investigation for localizing tumor is either CT or MRI of the
abdomen
 MRI is superior in identifying paragangliomas.

16. ANESTHESIA GOALS
• As mentioned earlier, pheochromocytoma resection is widely
considered to be among the most challenging in anesthetic
practice, with the primary goal being the delivery of an anesthetic
which provides stable hemodynamics in the face of catecholamine
surges (especially at laryngoscopy, peritoneal insufflation, surgical
stimulation, and tumor handling) followed by the opposite
scenario following tumor ligation. Careful planning and meticulous
technique are essential in addition to, close communication with
the surgical team.

17. PRE OPERATIVE MEASURES
• These measurements reduce the complications like
Hypertensive crisis
Wide BP fluctuations during manipulation of the tumor
Myocardial dysfunction that occurs during surgery
• These measures can reduce mortality from 40-60% (which was in 1951) to 6% (now a days)
• These measures are as following

18. • a-Adrenergic receptor blockade with prazosin (2-5mg) or phenoxybenzamine (10mg)
Which restores plasma volume by counteracting the vasoconstriction
this also causes little drop in hematocrit
 Initially start patient with:
20-30mg orally once or twice a day
can be increased to 60-250mg per day if no reduction in symptoms
• Efficacy of the drug is judged on:
 Reduction in sweating
 Stabilizing of BP
 if patient had carbohydrates intolerance, there is reducing in fasting sugar levels (a receptors
stimulation stops insulin release so alpha blockage reverse it) Patient who exhibit ST-T chances on ECG,
long term (0-6 months) therapy resolve myocarditis

19.  B adrenergic receptor blocker with propranolol is suggestive for patient with persistent arrhythmias.
 B adrenergic receptor blocker should not be given without a blockers because unopposed
vasoconstriction effects increase dangers of hypertension
 Calcium channel blockers are good for venospasm

20. ROIZEN CRITERIA
 No in-hospital blood pressure >160/90 mmHg for 24 h prior to surgery;
 No orthostatic hypotension with blood pressure <80/45 mmHg;
 No ST or T wave changes for 1-week prior to surgery;
 No more than 5 premature ventricular contractions per minute

21. WHAT ELSE CAN YOU DO BEFORE SURGERY?
• Relief from anxiety prior to anesthetic induction:
• Long acting benzodiazepine (diazepam or lorazepam night before surgery)
• IV midazolam prior to transfer to the operating room
• H2 receptor blockers
• Metoclorpramide is not recommended because causes increase in bp
• Droperidol – antiemetic inhibit catecholamine uptake

22. INTRAOPERATIVE PRINCIPLES
• Place an intra arterial catheter before induction
• Place intra venous catheter
• Central venous catheter
• Treat hemodynamic fluctuation
• Treat BP fluctuation
• Monitor hypotension and hypoglycemia after tumor isolation

23. PREMEDICATION
 Sedation, anxiolysis
 Benzodiazepine preferred
 Opioids can provoke catecholamine release
 Last dose of a adrenergic blocker should be given night before surgery

24. ANESTHETIC TECHNIQUE
 General anesthesia
 Regional anesthesia – mid to low thoracic
 Combined regional and general anesthesia (preferred)

25. INDUCTION
 Should be smooth
 Pre oxygenation
 Important for laryngoscopy and tracheal intubation
 2% lignocaine 1-1.5 mg/kg and Esmolol 50-100 microgram/kg/min
 Opioids
1) morphine/pethidin: causes histamine release
2) Fentanyl: most commonly used (2-5 mics/kg)
 Induction agents
1) thiopentone : can cause histamine release
2) etomidate: cardiovascularly stable
3) propofol: Logical choice

26. MUSCLE RELAXANT
 Succinylcholine: should be avoided becauses causes sympathetic stimulation
 Vecuronium, Rocuronium, Cisatracurium: Suitable agents
 Atracurium, Mivacurium: Histamine release

27. MONITORING
 ECG
 Pulse oximetry
 Invasive bp
 Cvp
 Urine output
 Temperature
 Inspired oxygen conc.
 EtCO2
 Blood sugar

28. MAINTENANCE
• Anesthesia depth more important than agent
1) Halothan/Enflurane- arrhythmogenic
2) Isoflurane- commonly used
3) Sevoflurane- preferred due to rapidly titrability of anesthetic depth
4) Desflurane- causes significant sympathetic stimulation
5) N2O – not contraindicated

29. INTRA-OP HYPERTENSION MANAGEMENT
• Manipulation of tumor leads to hemodynamic response which causes perioperative catecholamine
release
• Direct vasodilators:
 Sodium Nitroprusside: Potent arterio-venodilator, rapid onset, brief action, cyanide toxicity uncommon
with small quantity used (Initial 0.5 to 1.5µg/kg/min, mean 3 to 5 µg/kg/min) ○
 Nitroglycerine: Mainly affects capacitance vessels, rapid acting, large doss may be needed
α adrenergic antagonists:
 Phentolamine: Competitive α1 & weak α2 receptor antagonist, as infusion or 12 mg boluses, causes
tachycardia

30. β adrenergic antagonists- Help control tachycardia or tachyarrhythmias
 Esmolol: Ultrashort acting β1 antagonist. Rapid titrability. Uniquely suitable. Bolus
500μg/kg, infusion 50-200μg/kg/min
 Metoprolol 1-2 mg boluses
 Labetalol ( 0.25 mg/kg, upto 20 mg over a period of 10 min)
 Atenolol (2.5 to 10 mg), propranolol (1 to 10 mg) also used
Calcium channel blockers- little reduction in preload, less potential for overshoot
hypotension, no rebound hypertension, less increase in heart rate, absence of cyanide
toxicity
 Nicardipine: Inhibits CCA release from adrenal medullary cells in vitro, Intra-operative 2.5-
7.5μg/kg/min, onset 1 to 5 min, duration 3-6 hours
Dopa-1 receptor agonist-
 Fenoldopam: Peripheral vasodilation, ↑Renal blood flow. Undesirable diuresis

31. Magnesium sulphate-
 Inhibits CCA release from adrenal medulla, alters adrenergic receptor response
 Loading dose 40-60mg/kg followed by 1-2g/hr continuous infusion
 Target blood level 2-4 mmol/L
 Additional doses necessary during tumour handling
 Has been used in pregnant patients, patients with CAD

32. POST RESECTION HYPOTENSION
 After adrenal vein ligation and removal of tumor
 Reasons
1)Suppression of contralateral adrenal gland
2)Down regulation of adrenergic receptors
3)Effect of preoperative adrenoceptor antagonists
4)Sudden increase in venous capacitance
 Mostly amenable to modest fluid load and discontinuation of vasodilators
 Blood replacement according to losses
 Vasopressor if hypotension unresponsive to fluid
1)Noradrenaline
2)Phenylephrine
3)Dopamine
4)Angiotensin II agonist

33. POST OPERATIVE MANAGEMENT
 Reversal depends upon preoperative state and intraoperative course
 Neostigmine and Glycopyrrolate. Here, tachycardia associated with atropine can also occur hypertensive spike
 Shift to ICU/HDU
 Most important post-operative complications
 Hypertension: Approx. 50% patients
1)Recovery from anesthesia
2)Pain- Opioids, epidural analgesia, clonidine
3)Persistence of high plasma CCA level- restart anti hypertensives
4)Residual tumor- further evaluation and work up
 Hypotension:
1)Supression of contralateral adrenal
2)Down regulation of adrenoceptors
3)Persistent effect of preoperative adrenergic blockade
4)Intra-abdominal bleed- high index of suspicion

34. THANK YOU