Dr. S. Parthasarathy MD., DA., DNB, MD ( - PowerPoint Presentation

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Dr. S. Parthasarathy MD., DA., DNB, MD (Acu), Dip. Diab.DCA, Dip. Software statistics- PhdMahatma Gandhi Medical college and research institute , puducherry , India

Anaesthetic

management

o

f

pheochromocytoma

Slide2

What is it ??

Pheochromocytoma

is a rare catecholamine secreting tumor arising commonly from adrenal medulla and to some extent from other

paraganglia

of the sympathetic chain but can arise from any part of the body

Intra adrenal –

pheo

( WHO – 2004)

Others – extra adrenal

paragangliomas

with

an incidence of 1.55-2.1 per million

population

per year.

Slide3

Why is it so called ??

Pheo

--- dusk

Chromo – colored

Cytoma

--

tumour

Roux and Mayo performed

succesful

surgery in 1926

Still we are discussing

Slide4

the “rule of 10”

10% of the tumors are bilateral,

10% are extra-adrenal,

10% of the tumors undergo malignant change

10% of the patients,

pheochromocytoma

exist with various familial disorders such as multiple endocrine

neoplasia

(MEN) syndromes [MEN 2A and 2B], von Recklinghausen disease, and von

Hippel

Landau syndrome.

Slide5

MEN type IIA or IIB.

Type

IIA includes

medullary

carcinoma of the thyroid, parathyroid hyperplasia, and

pheochromocytoma

;

Type IIB consists of

medullary

carcinoma of the thyroid,

pheochromocytoma

, and

neuromas

of the oral mucosa.

Pheochromocytomas

may also arise in association with von Recklinghausen neurofibromatosis or von

Hippel-Lindau

disease (retinal and

cerebellar

angiomatosis

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Slide7

Clinical features

Slide8

Urine

Slide9

Systolic blood pressure changes – fluctuations present

Epinephrine

More consistent high BP –

norepinephrine

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Subtle signs

Paroxysmal hypertension associated with a normal blood pressure between crises occurs in 50% of patients.

30% of patients will have sustained hypertension.

Twenty-four–hour ambulatory blood pressure monitoring.

Orthostatic hypotension is also a common finding and considered to be secondary to

hypovolemia

and impaired venous and arterial vasoconstrictor reflex responses.

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Feeling of doom

“ I thought I was going to die “

Mimicking

Pregnancy ?? Toxemia

Slide12

Adult

pheochromocytomas

are solid, highly vascular tumors usually 3 to 5 cm in diameter and average 100 g in weight (range, 1.0–4000 g). The average-size adult

pheochromocytoma

contains 100 to 800 mg of

norepinephrine

.

Rt

adrenal more common

Slide13

How to diagnose ??

Secretions

Degradation products

Intratumour

degradation !!

Imaging

Slide14

Adrenal CT and MRI have comparable

sensitivity and specificity.

Metaiodobenzylguanidine

(MIBG) scanning offers superior specificity to MRI and CT, and is particularly helpful in localizing extra adrenal masses

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MRI imaging

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Normal plasma level of

catecholamines

…

- free epinephrine= 30 pg/ml (0.16 n mol/L)

- free norepinephrine= [200 – 1700 mcg/ml] 300

pg

/ml (1.8 n

mol

/L)

- free dopamine= [<30 mcg/ml] 35

pg

/ml (0.23 n

mol

/L)

T 1/2

~

2 minutes

Plasma

Metanephrines

May be interfered by drugs ?? Paroxysms

Slide17

Plasma free

normetanephrine

greater than 400 pg/

mL

and/or

metanephrine

greater than 220 pg/

mL

is diagnostic of a

pheochromocytoma

.

If

normetanephrine

is 112 to 400 pg/

mL

or

metanephrine

is 61 to 220 pg/

mL

, the diagnosis is equivocal.

A

pheochromocytoma

is excluded if

normetanephrine

is less than 112 pg/

mL

and

metanephrine

is less than 61 pg/

mL.

Slide18

24

hour urine

…

-

Normetanephrine

= 50 – 840 mcg/ml

-

Metanephrine

= 0 – 370 mcg/ml

-

Vanillylmandelic

acid (VMA)

= <7.2 mcg/ml

- Norepinephrine

= 13 – 107 mcg/ml

- Epinephrine

= 0 – 15 mcg/ml

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Clonidine

suppression

50 % suppression will not be there

Glucagon stimulation test

–increase plasma catecholamine but

bp

better with Pre admin with nifidepine

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Hyperglycemia Hypercholesterolemia Hyperenninemia Hypercalcemia Steroids Glucagon Anaemia or polycythemia

ECG ECHO Chest Xray

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Preoperative preparation

Rate

Blood pressure

Arrhythmias

End organ damage

WHY ??

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The treatment is only surgical

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The perioperative mortality associated with phaeochromocytoma is around 2% - unprepared may go upto 50 %

Induction without preparation may be hazardous

Venodilation

and

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catastrophy

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Alpha blockers

Phenoxybenzamine

oral

phenoxybenzamine

20 mg

tds

with a maximum dose of 250 mg.

a long duration of alpha blockade and non-competitive blockade as a result of covalent binding to drug receptors prevents the frequent surges of catecholamine releases during pre-op period.

it blocks alpha-2 receptors also thereby inhibiting the feedback loop for release of nor-epinephrine and as a result huge amount of nor-epinephrine is released causing undesirable

chronotropic

and

inotropic

effects

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Phenoxybenzamine

Increased post-op somnolence, headache, stuffy nose, and postural hypotension are some of the major side effects of

phenoxybenzamine

.

Insensitive to

postop

agonists

Can result in excess fluid administration and edema.

Tachycardia – beta blockers to be added –

aten

,

metoprolol

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So what do we need ??

Prazosin

1 mg

tds

upto

12 mg/ day – selective alpha 1 blocker

Doxazocin

2 – 4 mg/ day – long life

May not need beta blockers

Terazocin

– similar but shorter half life

Proved

doxazocin

+

labetolol

100 mg / day – effective

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Do we need beta blockers ??

Symptom free

Rate

Arrhythmias

Epinephrine and dopamine secreting

tumours

Beta blockers only after sufficient arteriolar dilation – 2 weeks of Alpha blockers

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Atenolol

100 mg/ day

Bisoprolol

10 – 20 mg / day

Labetolol

100 mg – 400 mg / day

Carvidolol

3. 25 mg

But

propronolol

– COPD and PAD

Celiprolol

– newer – 200 mg / day – beta 1 antagonist but beta 2 agonist

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Other drugs

SNP

0.5–1.5 µg/kg/min initially, increased to maximum of 8 µg/kg/min; titrate to

effect.

Powerful

vasodilator; short

acting.

Nicardipine

1–2 µg/kg/min increased to 7.5 µg/kg/min

;

titrate to

effect.

Octreotide

magsulf

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Adequate control achieved ??

BP 160/ 90 or less

Mild orthostatic hypotension > 80/45

No arrhythmias

ECG should be free of ST-T changes

Nasal congestion

Roizen’s

criteria

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Anaesthesia

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Goals

Intraoperative

goals include avoiding drugs or maneuvers that may provoke catecholamine release or potentiate catecholamine actions and maintaining cardiovascular stability, preferably with short-acting drugs.

Slide35

Intra op problems

hypertension and/or arrhythmias

anesthetic induction,

intubation, surgical incision,

abdominal exploration and particularly during tumor manipulation,

secondary to hypotension following ligation of the tumor’s venous drainage.

Slide36

Talk with the surgeon

Slide37

During laparoscopic surgery, creation of the

pneumoperitoneum

may cause release of

catecholamines

and large changes in

hemodynamics

that can be controlled with a vasodilator

Acute pulmonary edema can complicate the picture

Shorter post op stay !!!

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Monitors

Routine +

CVP –

pressure change of more than 10 with IPPV-

hypovolumia

Arterial catheter

PAC when dysfunction

Urinary output

TEE

Depth

Glucose , electrolytes

Slide39

Iv fluids

RL or physiologic saline are the recommended fluids for use prior to tumor removal and a dextrose-containing solution should be added after tumor removal.

A large positive fluid balance is usually required to keep intravascular volumes within a normal range.

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Anaesthetic concerns – technique does not matter

Prevent catecholamine surge

Decrease ANS involvement

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Factors that stimulate catecholamine release such as fear, stress, pain, shivering, hypoxia, and

hypercarbia

must be minimized or avoided in the

perioperative

period.

GA or RA + GA – OK

Midthoracic

epidural with GA

Can epidural block surges ??

Slide42

Anesthetic drugs that appear safe include thiopental,

etomidate

, benzodiazepines,

fentanyl

,

sufentanil

,

alfentanil

,

enflurane

,

isoflurane

, nitrous oxide,

vecuronium

, and

rocuronium

.

Despite these recommendations, the choice of anesthetic is not as crucial as the understanding with which the agents are used.

Slide43

Say no to drugs !!

Scoline

Atracurium

Morphine

Ephedrine

Metoclopramide

Ketamine

Desflurane

. Halothane

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Intra op hypertension

Usually surges of 200 mmHg

SNP

Phentolamine

Labetolol

dexmed

Isoflurane

Epidural

Slide45

Intra op arrythmias

Lignocaine

Esmolol

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Blood loss ??

No blood salvage

Inotropes ready –

phenylephrine

– better for hypo if volume status corrected

Vasopressin after clamps – better if down regulation suspected

Antiemetics

–

droperidol

0.625 mg IV with

dexa

Slide47

Postoperative Management

Patients usually remain in the ICU for at least 24 hours. Adequate pain control is essential, although somnolence and an increased sensitivity to narcotic analgesics have been observed.

The need for controlled ventilation is dictated by the extent of surgery, the site of surgery, and the patient’s medical condition.

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There are two adrenals !!!

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The majority of patients become

normotensive

following complete tumor resection.

Plasma catecholamine levels do not return to normal until 7 to 10 days after surgery due to a slow release of stored

catecholamines

from peripheral nerves.

Fifty percent of patients are hypertensive for several days following surgery,

25% to 30% of patients remain hypertensive indefinitely

Post op hypoglycemia ??

Slide50

Hypertension post op ??

Is there a metastasis ??

Is it incomplete ??

Is there a renal ischemia ??

Steroid supplementation is necessary for patients who had bilateral

adrenalectomies

or if

hypoadrenalism

is suspected.

Slide51

In emergencies – not a known case

Suspect

pheo

Vasodilators

Postpone surgery

Investigate and optimize

Slide52

Summary

Diagnosis

Investigations

Preop

Intra op

Post op

Slide53

Now-- what is the role of postgraduates?