Adrenal Insufficiency Flashcards
What are the causes of primary adrenal insufficiency (Addison’s Disease)?
1) Autoimmune adrenalitis: most common cause of Primary A-I (80-90%)
2) Infectious adrenalitis
- TB (calcified adrenals): 2nd most common cause
- Opportunistic infections in HIV e.g. CMV
3) Bilateral adrenal haemorrhage i.e. Waterhouse-Friderichsen Syndrome (in meningococcemia)
4) Genetic disorders such as CAH
5) Bilateral adrenalectomy
6) Drug-induced (etomidate, antifungals e.g. ketoconazole)
- Recall: this is the medical therapy for cushing’s!
7) Infiltrative
- Metastasis
- Lymphoma
- Amyloidosis
- Haemochromatosis
What are the causes of Secondary/ Central Adrenal Insufficiency i.e. decreased ACTH production?
*note that mineralocorticoid production remains INTACT as it is controlled by RAAS axi
Chronic exogenous glucocorticoid use from TCM, Hospital etc
- Chronic use causes negative feedback to decreased endogenous ACTH production 🡪 shutting down this axis
- Hence sudden reversal of chronic medications + acute insult will lead to ADDISONIAN CRISIS
- Hypopituitarism
Trauma / Radiation
- Surgery (eg: Trans-Sphenoidal Surgery)
- Macroadenomas
- Sheehan’s Syndrome causing Pituitary Apoplexy
What are the clinical features of primary adrenal insufficiency?
↓ Aldosterone
- HypoTN / Orthostatic
- HypoNa
- HyperK
- NAGMA: HyperK 🡪 rTA
↓ Cortisol
- LOW, LOA, Lethargy
- Depression
- GI S/E: N&V, Diarrhoea
- HypoTN / Orthostatic
- Hypogly
- HypoNa
↓ Androgens
(Females only)
- Loss of libido
- Loss of axillary and pubic hair
↑ ACTH: Hyperpigmentation of areas that are not normally exposed to sunlight (e.g., palmar creases, mucous membrane of the oral cavity)
What are the clinical features of secondary adrenal insufficiency?
↓ Cortisol
- LOW, LOA, Lethargy
- Depression
- GI S/E: N&V, Diarrhoea
- HypoTN / Orthostatic
- Hypogly
- HypoNa
↓ Androgens
(Females only)
- Loss of libido
- Loss of axillary and pubic hair
What is the most important triad to recall 1st as a clinical presentation of adrenal insufficiency?
- Hypotension
- Hyponatraemia: because of loss of ACTH suppression by cortisol
- Hypoglycaemia: since cortisol is a counter-regulatory hormone
What is the investigations to work out hypocortisolism?
1) 8 am cortisol
- Random cortisol in urgent situations/ or start dexamethasone
- Note binding of cortisol to albumin / CBG (can be falsely low cortisol values if albumin low)
2) Serum ACTH – Differentiates primary and secondary cause
3) Standard short Synacthen test (250mcg) im/iv aka cosyntropin test
- To assess the function of Adrenals w ACTH stimulation: Serum cortisol is measured before SST, 30th min after, & 60th minute after (0, 30, 60 min)
4) Complications
- Capillary Blood Glucose: Hypoglycaemia
- Blood pressure: Hypotension
- Plasma Renin & Aldosterone levels: for hypoaldosteronism
- Total testosterone + SHBG: for Hypoandrogenism (in females)
- Renal panel & U/E/Cr: Hyponatraemia (since cortisol serves to ↓ ADH release via -ve feedback)
+/- Hyperkalaemia
What are the investigation results if Pri Hypocortisolism?
↑ ACTH, Suboptimal Synacthen Stimulation
What are the investigation results if Acute Sec Hypocortisolism?
↓ ACTH, Optimal Synacthen Stimulation
What are the investigation results if Chronic Sec Hypocortisolism?
ACTH, Suboptimal Synacthen Stimulation
What is the further workup for primary adrenal insufficiency?
Screen for adrenal antibodies and other autoimmune diseases e.g., Hashimoto thyroiditis, pernicious anemia, type 1 DM
What is the further workup for secondary adrenal insufficiency?
If secondary
- MRI brain
- TRO Exogenous Steroid Use
What is the management of a patient with adrenal insufficiency?
Hydrocortisone (given because short acting)
- If PRIMARY Hypocortisolism: 10mg on waking, 5mg at noon, 5mg at 5pm
- If SECONDARY Hypocortisolism: 10mg on waking, 5mg at 5pm
Aldosterone replaced in primary AI (not secondary): 50-100 μg fludrocortisone / day
Sex steroids (for woman- woman’s choice )
- Androgen replacement helps to reduce libido and improve QoL
- However generally we DO NOT REPLACE
No need to replace adrenalinesince medulla function is NOT affected in both 1’ & 2’ A-I
How much hydrocortisone should the patient take if they are sick?
Mild-moderate illness (eg: runny nose, sore throat) <39 degrees 🡪 2x dose for 3 days till mild illness is over
Severely unwell >39 degrees 🡪 Please come to hospital for parenteral steroids
What are the side effects of fludrocortisone?
If excessive replacement – HTN, HypoK (S&S of weakness, Polyuria)
If insufficient – Hypotension, Postural Hypo, HypoNa, HyperK
What are the S/E of overtreatment of adrenal insufficiency
- Endocrine: weight gain, worsening/ new onset of DM
- GI: dyspepsia, PUD
- Psych: confusion, irritiability, suicidal thoughts
- MSK: osteoporosis, proximal myopathy
- opthal: glaucoma and cataracts
- CVS: oedema, HTN, electrolyte abnormalities
- Skin: thinning of skin and delayed wound healing
- Immunosuppresion: Increased risk of infection
- Irreversible growth suppression in children and young people
