Endocrine - Adrenal

Question 1

Adrenal Gland

Answer 1

Cortex 80-90%

Medulla 10-20%

Question 2

Adrenal Gland Function

Answer 2

• Blood glucose regulation
• Protein turnover
• Fat metabolism
• Na+/K+/Ca2+ balance
• CV tone maintenance
• Modulates tissue response to injury or infection
• Stress response*

Question 3

Adrenal Cortex

Answer 3

Zona glomerulosa - aldosterone (mineralocorticoid)
Zone fasciculata - cortisol (glucocorticoid)
Zona reticularis - androgenic

Question 4

Adrenal Medulla

Answer 4

Epinephrine 80%

Norepinephrine 20%

Question 5

Cushing’s Syndrome

Answer 5

Any excessive cortisol secretion
Exogenous steroids
ACTH dependent or independent

Question 6

Cushing’s Disease

Answer 6

Inappropriate ACTH from anterior pituitary secretion
1° pituitary tumor
2° adrenal tumor

Question 7

ACTH Dependent

Answer 7

Pituitary corticotrophy tumors (microadenomas)
Non-endocrine tumors - lung, kidney, or pancreas
Ectopic corticotrophin syndrome

Question 8

ACTH Independent

Answer 8

Benign or malignant adrenocortical tumors

Question 9

Cushing’s S/S

Answer 9

Sudden weight gain (central)
Facial fat "moon face"
Electrolyte abnormalities
Systemic HTN
Glucose intolerance
Menstrual irregularities
Decreased libido
Skeletal muscle wasting
Depression & insomnia
Osteoporosis
Hypercoagulable

Question 10

Cushing’s Diagnosis

Answer 10

Plasma & urine cortisol levels
CRH stimulation test
Dexamethasone suppression test
Inferior petrosal sinus sampling

Question 11

Cushing’s Treatment

Answer 11

Surgical
- Transsphenoidal microadenectomy
- Adrenalectomy
Irradiation

Question 12

Cushing’s

Anesthetic Management

Answer 12

Preop evaluation - HTN, intravascular volume, electrolytes, hypokalemia metabolic alkalosis, CHF, glucose control
Positioning - osteoporosis/osteomalacia vertebral compression fractures
Skeletal muscle weakness - ↓muscle relaxants requirements (maintain 1 twitch)
Cortisol - 100mg IV glucocorticoid intraop
Blood loss - type & screen, CVP, A-line
Anesthetic agents - depress adrenal response to stress & ACTH

Question 13

Cushing’s

Anesthetic Complications

Answer 13

Transsphenoidal microadenomectomy
- VAE
- Transient DI
- Meningitis
Adrenalectomy
- Laparoscopic vs. open
- Pulmonary complications

Question 14

Conn’s Syndrome

Answer 14

Excessive aldosterone

Question 15

Primary Hyperaldosteronism

Answer 15

Excessive aldosterone secretion from functional tumor

Question 16

Secondary Hyperaldosteronism

Answer 16

↑circulating serum renin stimulates aldosterone release (renovascular HTN)

Question 17

Conn’s S/S

Answer 17

Non-specific
Asymptomatic
Systemic HTN (headache, diastolic BP 100-125mmHg) reflects aldosterone induced Na+ retention ↑fluid retention
Hypokalemia - skeletal muscle cramps, weakness, metabolic acidosis

Question 18

Hyperaldosteronism

Anesthetic Considerations

Answer 18

Correct ↓K+
Avoid hyperventilation → hypokalemia
HTN (A-line)
Assess cardiac/renal status
Fluids w/ vasodilators & diuresis
Monitor acid-base balance
Replace exogenous cortisol 100mg/day

Question 19

Addison’s Disease

Answer 19

1° adrenal insufficiency
- Most common cause idiopathic/autoimmune
- Asymptomatic until 90% adrenal cortex destroyed
Deficiency all adrenal cortex secretions - mineralocorticoids, glucocorticoids, & androgens

Question 20

Addison’s S/S

Answer 20

Chronic fatigue
Muscle weakness
Hypotension
Weight loss
Anorexia
Nausea/vomiting
Diarrhea
↑BUN
Hyponatremia
Hyperkalemia
Hypoglycemia
Abdominal or back pain
Hyperpigmentation

Question 21

Addison’s Diagnosis

Answer 21

Baseline plasma cortisol level <20mcg/dL
Cortisol level <20mcg/dL after ACTH stim test
- Normal response >25mcg/dL
- Positive test indicates adrenal cortex impairment

Question 22

Addisonian Crisis

Answer 22

Steroid-dependent who do not receive ↑dose during stress
Stress → circulatory collapse
- Hypoglycemia
- Electrolyte imbalance
- Depressed mentation
100mg IV cortisol Q4-6H
Inotropic support

Question 23

Addison’s

Anesthetic Considerations

Answer 23

Administer exogenous corticosteroids
Continue steroid dose DOS
Intraop hypotension
- Measure CVP
- Vasopressor
- Fluids
- Cortisol 100mg IV
Measure blood glucose
Monitor electrolytes (avoid LR)
Avoid Etomidate
Inhalational agents sensitive to drug-induced myocardial depression
Titrate muscle relaxants d/t skeletal muscle weakness

Question 24

Minor Surgery Cortisol

Answer 24

25mg hydrocortisone

Question 25

Major Surgery Cortisol

Answer 25

100mg bolus followed by infusion at 10mg/hr OR 100mg Q6H

Question 26

Hypoaldosteronism

Answer 26

Congenital aldosterone deficiency Hyporeninemia loss angiotensin stim Non-steroidal inhibit prostaglandin synthesis - inhibit renin release & exacerbate condition in renal insufficiency

Question 27

Hypoaldosteronism S/S

Answer 27

Hyperkalemic acidosis Severe hyperkalemia Hyponatremia Myocardial conduction defects

Question 28

Hypoaldosteronism Treatment

Answer 28

Mineralocorticoid-fludrocortisone | Liberal Na+ intake

Question 29

Pheochromocytoma

Answer 29

Catecholamine-secreting tumor Originates in adrenal medulla & related tissues Most common young to mid-adult life

Question 30

Pheochromocytoma S/S

Answer 30

``` 1° - HTN continuous or paroxysmal - Headache - Diaphoresis/pallor - Palpitations or tachycardia Associated S/S - Orthostatic hypotension d/t volume depletion - Anxiety - Tremors - Chest pain - Epigastric pain - Flushing - Painless hematuria ```

Question 31

Pheochromocytoma | Duration & Frequency

Answer 31

1hr or less | Daily to once every few months

Question 32

Pheochromocytoma Diagnosis

Answer 32

``` Urine tests Plasma levels* NE/Epi breakdown products - Normetanephrine >400 - Metanephrine >220 CT/MRI ```

Question 33

Pheochromocytoma Treatment

Answer 33

``` Surgical excision α blockade - Phenoxybenzamine α 1&2 - Prazosin selective α1 Restore intravascular volume ↓Hct Insulin release Persistent tachycardia β blockade (Esmolol) DO NOT ADMINISTER NON-SELECTIVE β BLOCKADE W/O α BLOCKADE (unable to maintain CO) ```

Question 34

Pheochromocytoma | Preop Considerations

Answer 34

Optimize the patient ↑SVR → myocardial ischemia, ventricular hypertrophy, CHF, cardiomyopathy Cerebral hemorrhage history Hyperglycemia ↓circulating insulin w/ ↑glycogenolysis Blood pressure <165/90 48hours prior to surgery Standing BP >80/45 EKG w/o ST or T wave changes <1 PVC Q5min

Question 35

Pheochromocytoma | Anesthetic Considerations

Answer 35

``` Communication w/ surgeon Continue adrenergic blockade Fluid management: - Pre-hydrate hypovolemia - Falsely ↑Hct - Type & cross - Renal function - Fluid replacement plan Benzodiazepine & opioid pre-medication A-line ```

Question 36

Pheochromocytoma | Induction & Laryngoscopy

Answer 36

``` Lidocaine 1-2mg/kg Opioid (no Morphine d/t histamine & catecholamine release) to blunt SNS response - Sufentanil 0.5-1mcg/kg - Fentanyl 3-5mcg/kg Propofol 3mg/kg Nitroprusside 1-2mcg/kg Phentolamine α blocker Esmolol β blocker Avoid drugs that release histamine ```

Question 37

Pheochromocytoma | Intraop Considerations

Answer 37

MAC 1.5-2 Combined general anesthetic w/ continuous lumbar epidural Muscle relaxant - Vecuronium or Rocuronium Surgical ligation tumor venous drainage ↓catechols → prepare for hypotension - DC antihypertensives - ↓volatile inhalational agent - Volume 1st - Administer pressors (phenylephrine or norepinephrine) NE infusion until vasculature adapts to ↓α stim

Question 38

Pheochromocytoma | Cardiovascular Control

Answer 38

``` Nitroprusside preferred Phentolamine - tachyphylaxis, tachycardia, & longer duration Magnesium sulfate Ca2+ channel blockers Esmolol preferred Labetalol Metoprolol ```

Question 39

Pheochromocytoma | AVOID

Answer 39

Histamine releasers (Morphine or Atracurium) Halothane - sensitizes myocardium → epinephrine Succinylcholine fasciculations → catechol release from tumor Avoid ↑HR (Pancuronium or Atropine) Metoclopramide → catechol release

Question 40

Pheochromocytoma | Postop Considerations

Answer 40

Adequate analgesia - PCA & opioids 50% patients remain HTN - Elevated catecholamine levels 10 days postop - Continue antihypertensive therapy Early extubation (young, no lung involvement) Hypoglycemia d/t excess insulin release & ineffective lipolysis & glycogenolysis Steroid supplementation d/t adrenal manipulation Postop HTN > 10 days - Occult tumors (repeat surgery) - Volume overload - Continue monitoring