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Adrenal Problems
Anatomy
Pathophysiology
Adrenal
OVERLOAD
(Cushing’s
syndrome)
Aldosterone
OVERLOAD
Zona glomerulosa: outer; aldosterone
Zona fascitulata: middle; cortisol
Zona reticularis: inner; androgens
CRH from hypothalamus  ACTH from APG  Cortisol from adrenal cortex
Effects of cortisol:  release of CRH and ACTH
Gluconeogenesis, lipolysis
 ketogenesis,  insulin release   BSL
 effects of cytokines,  cell mediated immunity, anti-inflammatory
RAA  aldosterone from adrenal cortex
Effects of aldosterone:  Na ( reabsorption),  H20 excretion
 K ( excretion) in DCT
alkalosis ( H excretion)
Cause: Iatrogenic (steroids, ACTH; most common cause)
Pituitary adenoma (Cushing’s disease)
Adrenal adenoma / cancer / hyperplasia
Ectopic CRH (eg. Pancreas, bronchial carcinoid, thymic cancer)
Ectopic ACTH (20%; eg. Oat cell cancer lung)
Examination: moon face, buffalo hump, truncal obesity, acne, striae, hursutism, atrophic skin,
osteoporosis, HTN, peri oedema, diabetes, psych (>70%), bitemporal hemianopia, adrenal cancer
If 2Y to ACTH – no Cushingoid fetaures, but HTN, oedema, prox myopathy, hyperpigmentation, cachexia
Investigations: hyper HTN / glycaemia
Hypo K
Metabolic alkalosis
 Hb,  neutrophils
Cortisol: at 00:00; >200 = Cushings
24hr urinary cortisol: 85% sensitivity; false –ive if dilute urine
Corticotropin
Dexamethasone suppression test: 24hr urine for 2/7; cortisol and ACTH blood test at
09:00; dexamethason 1mg given at 11pm; normal should be  to <50% baseline level
Cause: 1Y: Conn’s syndrome (F:M 2:1; adenoma in F, hyperplasia in M)
2Y: due to RAA from  blood flow or perfusion pressure; underlying oedematous disorder;
congestive cardiac failure, chronic liver / renal failure, renal artery stenosis; Bartter’s
syndrome (normal BP, no oedema, hypoNa)
Examination: HTN, weakness, paraesthesia, polyuria
Investigation: hyper Na / volaemia / HTN
Hypo K / Ca
Metabolic alkalosis
Renin and aldosterone mid-morning
Adrenal
Insufficiency
Cause: can be precipitated by: surgery, MI, general anaesthetic, hypoglycacemia, hypothermia, trauma,
psych illness, drugs
1Y: there is an aldosterone deficiency  hypovolaemia, high K
adrenal haem (anticoagulants, neonates, sepsis – Freidrich-Waterhouse syndrome)
Addison’s disease (80%)
Autoimmune diseases (70%; eg. Antiphospholid syndrome)
Surgical removal
Drugs (long term steroids most common cause – recovery post-steroids takes 1-12/12;
ketoconazole)
Infection (TB – most common infectious cause worldwide, AIDS – mot common infectious cause in
USA (20%), protozoa, CMV, HSV); 60% patients with sepsis have decr cortisol
Cancer (usually 1Y; lung and lymphoma most common cause of 2Y)
Congenital adrenal hyperplasia: vague presentation at 2wks; look for virilisation
Other (sarcoidosis, haemochromatosis, hereditary)
2Y: aldosterone is normal  euvolaemia, low K
pituitary failure, hypothalamic failure, head trauma, meningitis, irradiation / post op, Sheehan
syndrome
Pathophysiology: 90% of gland must be destroyed to cause hypoadrenalism
Results in: 1Y: Hypo Cl / Na / osmolality / volaemia (Na rarely <120; total body depletion + intracellular
movement)
Hyper K (rarely >7; extracellular mvmt + decr excretion)
Non- anion gap metabolic acidosis
Always consider if fluid-resistant hypotension
2Y: no volume depletion; low K; high / low Na; little other change in elecrolytes as aldosterone
normal
Symptoms: anorexia, nausea and vomiting, diarrhoea, abdominal pain, lethargy, weight loss, weakness,
postural syncope
Examination: pigmentation if 1Y; SBP <100 with postural drop
Investigation: as above +  creatinine, mild  Ca (in 10-20%), mild hypoglycaemia; anti-adrenal
antibodies
Cortisol: within 1hr of waking; <200 = insufficiency; 200-500 = needs ACTH stimulation test
ACTH stimulation test: bloods  Synacthen IM  bloods 30mins  bloods 60mins  cortisol >550 =
normal; if normal response = 2Y
ACTH: high = 1Y; low = 2Y
Mng: IV fluid (may need ++); treat hypoglycaemia; treat K if needed; vasopressors may be needed
If uncertain diagnosis: Dexamethasone 10mg IV stat  4mg QID
If certain: hydrocortisone 250mg IV stat  100mg QID; 25mg IV if neonate, 50mg IV toddler to
school child, 100mg to adolescents