adrenal disorders-kuliah update.ppt...
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ADRENAL DISORDERS
Mardianto
Divisi Endokrin dan Metabolik
Bagian Penyakit Dalam FK USU
RSUP H. Adam Malik
Medan
Cross section through the adrenal gland– cortex and medulla
salt
sugar
sex
CRHCRH CortisolCortisolCortisolCortisol
Circadian regulationCircadian regulationStress:Physical stressEmotional stressHypoglycemiaCold exposurePain
Stress:Physical stressEmotional stressHypoglycemiaCold exposurePain
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Hypothalamus-Pituitary-Adrenal axis
Anterior lobeof pituitary glandAnterior lobeof pituitary gland
ACTHACTHACTHACTH
CortisolCortisolCortisolCortisol
Adrenal cortexAdrenal cortex+
+
-
Kirk LF. Am Fam Physician 2000CRH=corticothropin releasing hormone; ACTH=adrenocorticothropin hormone.
Regulation of aldosterone secretion
Components of renin-angiotensin-aldosterone aldosterone system
Action of aldosterone on the renal tubule.
Production of
catecholamines
COMT = Catecholamine Ortho Methyl Transferase)
Adrenocortical disorders
Cushing’s Syndrome
• Supraphysiologic glucocoticoid exposure
(excess cortisol)
– Protein catabolic state
– Liberation of amino acids by muscle– Liberation of amino acids by muscle
– AA are transformed into glucose and glycogen and
then transformed into fat
• The source of excess glucocorticoids may be
exogenous or endogenous
Causes of Cushing’s Syndrome
• ACTH Dependent (80%)– Cushing’s Disease (85%)
• Primary excretion of ACTH from pituitary– Microadenoma, macroadenoma or corticotrophic hyperplasia
– Basophilic or chromophobe
• F>M (3:1)• F>M (3:1)
– Ectopic source (15%)• Produce ACTH or CRH
• Small cell lung CA (most common), carcinoid tumors, medullary thyroid, pancreas, ovarian, pheochromocytoma, small-cell CA of prostate
Causes of Cushing’s Syndrome
• ACTH Independent
– Exogenous steroid use (common)
• PO or topical
• Most common cause (overall)• Most common cause (overall)
– Adrenal adenomas (10%)
– Adrenal carcinoma (5%)
• Most common cause in children
Cause of Cushing’s Syndrome
• Pseudo-Cushing’s disease
– Mimic clinical signs and symptoms
– Non-endocrine causes– Non-endocrine causes
• Alcoholism
• Major depression
• Morbid obesity
• Acute illness
Cushing’s Syndrome
Symptoms and Sign Percent of Patients
• Weight gain, round facies and
truncal obesity
• Weakness
• Hypertension
97
87
82• Hypertension
• Hirsutism (in women)
• Amenorrhea
• Cutaneous striae
• Ecchymoses
• Osteoporosis
• Hyperglycemia
82
80
77
67
65
Common
Common
Diagnosis of Cushing’s Syndrome
• Clinical assessment
• Screening tests :
– Baseline glucocorticoids (a.m. and p.m. serum cortisol levels, 24-hr urinary free cortisol excretion; 11 p.m. Salivary cortisol)
– Low dose dexamethasone suppression test or combined low-dose dexamethasone-oCRH low-dose dexamethasone-oCRH
• Subtype diagnosis
– Plasma ACTH concentration
– Dynamic testing (oCRH stimulation test, metyrapon stimulation test, high dose dexamethasone supression test) – all with limited utility or prescision
– Directed computerized imaging (pituitary, adrenals, lungs, etc)
– Pituitary venous sampling for ACTH with CRH stimualtion
Diagnosis of Cushing’s Syndrome• Screening tests
– 24 hour urinary cortisol (UFC)
• RIA : 80-108µg (221-298nmol)
• Baseline 24-hour UFC measurements may be high : Carbamazepin, high urine volume, severe illness, CS, alcoholism, depression, sleep apnea.
– Late night plasma or salivary cortisol – Late night plasma or salivary cortisol
• A midnight sleeping serum cortisol concentration > 1.8µg/dl (>50nmol/L) is 100% sensitive in patients with Cushing’s syndrome.
– Overnight 1-mg dexamethasone supression test (DST)
• A failure to supress serum cortisol with 1-mg DST is positive screen and should lead to confirmatory evaluations.
• Causes for cortisol non-supression with the overnight 1-mg DST incl : CS, patient error in taking, estrogen therapy, pregnancy, renal failure, stress, drugs (anticonvulsants, rifampisin), obesity, psychiatric disorder (depression, panic attacks)
Diagnosis of Cushing’s Syndrome
• Confirmatory tests for CS
– When baseline 24-hour UFC is >300µg (828 nmol) and the
clinical and the clinical picture is consisten with CS : no
additional confirmatory studies are needed.
– 2-day low dose DST
• 24-hour UFC < 300µg : should confirmed with the low dose DST • 24-hour UFC < 300µg : should confirmed with the low dose DST
(dexamethasone 0.5 mg, orally every 6 hours for 48 hours); 24-
hour urinary cortisol excretion > 20 µg (55nmol) confirm
diagnosis.
• The low dose DST works best for those patients that carry of low
index of suspicion for CS.
– Dexamethasone –oCRH test
• To correct false negative supression with DST (pituitary dependent
CS)
Clinical Suspicion of Cushing’s Syndrome
1 mg DST
Normalsupression
24 hour UFC
Elevated(>300µg/d)
Intermediate(90-300µg/d) Normal
(<90µg/d)Repeat, if normal
Cushing’s Syndrome
No supressionConfirm with 24 hr UFC
Cushing’ Syndrome
Diurnal variationAnd/or Dex-CRH test
Repeat, if normalCushing’s Syndrome
unlikely
Continue Evaluation
Cushing’ syndrome doubful
PsudoCushing’s
Treat underlying illness
Follow clinical examination
Repeat evaluation
Differential Subtype Evaluation Tests
• Plasma ACTH concentration– ACTH dependent (‘normal’ to high levels of ACTH or ACTH independent
(low/undetectable ACTH)
– IRMA assay : normal 10-60 pg/ml, plasma ACTH values are <5 pg/ml in adrenal dependent disease, 10 to 200 pg/ml in pituitary-dependent disease, and 50 to >200 pg/ml in ectopic ACTH syndrome
• ACTH Dependent Disease– Pituitary MRI– Pituitary MRI
– Inferior petrosal venous sampling (IPSS) with CRH stimulation
• Measure petrosal venous sinus ACTH level and correlate to plasma levels• The most important advanced in the past 2 decades for subtype evaluation of CS
• IPSS does not diagnose Cushing’s syndrome
– CRH stimulation test
– High dose DST
– Positron emission scanning: occult neuroendocrine and ather ACTH-secreting tumors
No test is perfect for subtype evaluation of Cushing’s syndrome!
Cushing’s Syndrome• Treatment program :
– The resolution of hypercorticolism
– The parellel treatmet of the complications of CS (e.g. hypertension, osteoporosis, diabetes mellitus, mucle rehabilitation)
– Management of glucocorticoid withdrawal and hypothalamic pituitary-adrenal (HPA) axis recovery
• Treatment: Surgical– Cushing’s disease– Cushing’s disease
• Transphenoidal surgery (TSS)– The treatment choice
– The longterm surgical cure rate for ACTH secreting microadenomas is 80-90%.
– Transient post-op diabetes insipidus, adrenal insufficiency, CSF rhinorrhea, meningitis
• Tansphenoidal irradiation– If TSS is not curative.
– High success rate in kids (80%)
– Low success in adults (20%)
Cushing’s Syndrome
• Treatment: Surgical
– Cushing’s disease
• Bilateral adrenalectomy
– If failed pituitary surgery
– Life-long steroid replacement– Life-long steroid replacement
– Adrenal lesions/carcinoma
• Removal of primary lesion
• Survival based on underlying disease
– Ectopic ACTH lesions
• Remove lesion
• Survival based on primary disease
• May need bilateral adrenalectomy to control symptoms if primary
tumor unresectable
Cushing’s Syndrome
• Treatment: Medical
– Used as prep for surgery or poor operative candidate
• Metyrapone- inhibits conversion of deoxycortisol to cortisol
• Aminoglutethimide-inhibits desmolase
– Cholesterol to pregnenolone– Cholesterol to pregnenolone
– Blocks synthesis of all 3 corticosteroids
– Side effects: N/V, anorexia, lethargy
• Ketoconazole- an imidazole that blocks cholesterol synthesis
• Mitotane (O-P-DDD)-inhibits conversion to pregnenolone
– Inhibits final step in cortisol synthesis
– Destroys adrenocortical cells (spares glomerulosa cells)
Addison’s Disease
• Background: Thomas Addison first described the clinical presentation of primary adrenocortical insufficiency (Addison disease) in 1855 in his classic paper, On the Constitutional and Local Effects of Disease of the Supra-Renal Capsules.
• Pathophysiology: • Pathophysiology:
– Addison disease is adrenocortical insufficiency due to the destruction or dysfunction of the entire adrenal cortex.
– It affects both glucocorticoid and mineralocorticoid function.
– The onset of disease usually occurs when 90% or more of both adrenal cortices are dysfunctional or destroyed.
Cortisol ↓
• Abdominal pain
• Anorexia
• Vomiting
• Diarhea
Gluconeogenesis ↓Glucose uptake ↓
Renal K Secretion ↓Renal Na secretion ↑
ACTH ↑
Fluid intake ↓ Hypoglycemia Hyperkalemia
Hyperpigmentation
dehydration
Hypotension
Hypovolemia
Renal perfusion ↓BUN ↑
Hyperkalemia
Hyponatremia
Decreased Body Weight
General Weakness
Addison’s Disease
• Primary adrenal insufficiency– Causes
• Infectious
– TB – most common cause in 3rd world countries
– HIV, histoplasmosis, blastomycosis, coccidiomycosis
• Autoimmune disorders – anti-adrenal antibodies (most • Autoimmune disorders – anti-adrenal antibodies (most cause common)
• Medications – ketoconazole, aminoglutethamide, etomidate
• Adrenal hemorrhage
• Lymphoma, bilateral adrenal metastasis, Kaposi’s sarcoma
• Infiltrative – amylodosis, sarcoidosis, adrenoleukodystrophy
Addison’s Disease
• Secondary adrenal insufficiency
– Pituitary failure – panhypopitutarism, Sheehan’s syndrome (post-partum pituitary injury)
• Tertiary adrenal insufficiency
– Adrenal suppression due to glucocorticoid use
• Chronic suppression
• Sudden cessation of replacement glucocorticoids
• Inadequate increase during stress, trauma, surgery
Primary Adrenal Insufficiency
Symptoms and sign Percent of
Patients
Weakness and fatigue 99Weakness and fatigue
Hyperpigmentation
Unexplained weight loss
Anorexia, nausea, and vomiting
Hypotension (BP < 110/70 mmHg)
Hyponatremia
Hyperkalemia
99
98
97
90
88
88
64
Primary Adrenal Insufficiency
A triphasic pattern :
• Phase 1 : few/no symptoms, non spesific malaise,
pigmentation
• Phase 2 : gradually worsening simptoms ;
lethargy, weight loss, increased pigmentation over
exposed areas, hypotension, anorexia, nausea,
diarhoea, loss axillary, pubic and body hair
• Phase 3 : decompentation ; adrenal crisis,
Primary versus secondary adrenal
insufficiency
Manifestations Primary Secondary
Hyperpigmentation
Pallor
Yes
No
No
YesPallor
Low Na
High K
Hypotension
Cortisol level
ACTH level
No
Yes
Yes
Yes
Low
High
Yes
No
No
No
Low
Low
Addison’s Crisis
• Acute adrenal insufficiency
– Similar causes
• Adrenal hemorrhage
• Chronic steroid use and trauma/stress/surgery• Chronic steroid use and trauma/stress/surgery
– Hypotension, volume depletion, fever, nausea and vomiting, tachycardia, weakness, hypoglycemia
– Premed prior to interventions
Addison’s Crisis
Treatment acut of adrenal crisis• The five S’s management are salt, sugar, steroid, support,
and search for presipitating illness.
• General and supportive measure– Correct volume depletion, dehydration, and hypoglycemia with IV
0.9% saline with 5% dextrose– Correct volume depletion, dehydration, and hypoglycemia with IV
0.9% saline with 5% dextrose
– Evaluate and correct infection and other precipitating factors
• Glucocorticoid replacement– Administer hydrocortisone 100 mg every 6 hours for 24 hours
– When the patient is stable, reduce the dosage to 50 mg every 6 hours
– Taper to maintenance theraphy by day 4 or 5 and add mineralocorticoid theraphy as required
– Maintain or increase the dose to 200-400 mg/d if complications persist or occur
Addison’s Crisis
Maintenance therapy
• Glucocorticoid and mineralocorticoid
– Oral dose hydrocortisone : 10-20 mg in the morning
and 5-10 mg later in day. and 5-10 mg later in day.
– Fludrocortisone : 0,05-0,2 mg/d orally in the morning.
• Response to theraphy
– General clinical sign, good appetite and sense of well
being.
– Signs of Cushing’s syndrome indicate overtreatment
Disorders of adrenal medullary
functionfunction
Pheochromocytoma
• Pheochromocytoma is a rare catecholamine-secreting tumor derived from chromaffin cells.
• Tumors that arise outside the adrenal gland are termed extra-adrenal pheochromocytomas or paragangliomas.
• Because of excessive catecholamine secretion, • Because of excessive catecholamine secretion, pheochromocytomas may precipitate life-threatening hypertension or cardiac arrhythmias
• It is associated with spectacular cardivascular disturbances and, when corectly diagnosed and treated � curable. When undiagnosed � fatal
• Prevalence estimates – 0.01% to 0.1% of the hypertensive population
Pathophysiology
• The clinical manifestations of a pheochromocytoma result from excessive catecholamine secretion by the tumor.
• Catecholamines typically secreted, either intermittently or continuously, include norepinephrine and epinephrine and rarely dopamine.
• The biological effects of catecholamines are well known. • The biological effects of catecholamines are well known.
• Most pheochromocytomas contain norepinephrine predominantly, in comparison with the normal adrenal medulla, which is composed of roughly 85% epinephrine.
• Familial pheochromocytomas are an exception because they secrete large amounts of epinephrine. Thus, the clinical manifestations of a familial pheochromocytoma differ from those of a sporadic pheochromocytoma.
Receptor catecholamine :
• Receptor α (NE)
• Receptor β (EPI)
Pheochromocytoma• Symptoms :
– Due to the pharmacologic effects excess circulating catecholamines
– A typical paroxysm (the 5 P’s)• Pressure – sudden major increase in blood pressure
• Pain – abrupt onset of throbbing headache ; chest and abdominal painabdominal pain
• Perspiration – profuse generalized diaphoresis
• Palpitation
• Pallor
• Clinical sign : • Hypertension,orthostatic hypotension, grade II to III
retinopathy, tremor, weight loss, fever, painless hematuria, hyperglycemia, erythrocytosis
Pheochromocytoma
• Diagnosis :
– Demonstration of excessive amounts catecholamines in plasma or urine or degradation product in urine
• Urinary metanephrine, normetanephrine, vanilmandelic acid (VMA), and free catecholamine in 24-hour periodeand free catecholamine in 24-hour periode
• Direct measurement plasma NE and EPI. Levels > 2000 pg/ml are abnormal and suggestive Pheochromocytoma
– Clonidine suppression test
• Clonidine orally 0,3 mg; plasma catecholamine : before oral clonidine and again at 1,2 and 3 hr after oral clonidine
• Plasma catecholamine >500pg/ml
– Glucagon stimulation test
Pheochromocytoma
• Treatment :
– Surgical resection is only definitive therapy
– Preoperative preparation with alpha blockade reduce the incidence intraoperative hypertensive reduce the incidence intraoperative hypertensive crisis and postoperative hypotension
– The most commonly used agents are phenoxybenzamine (10-20 mg 2-3 times/d, or prazosin 1mg 3 times/day, advanced to 5 mg 3 times/day (7-28 days before surgery)
– Other agents labetalol or Ca channel blocker