Endocrinology - Endocrine emergencies Flashcards
What is myxoedema coma?
This is the consequence of severely depleted thyroid hormones and is the ultimate hypothyroid state before death.
What are the signs and symptoms of myxoedema coma?
The patient looks hypothyroid, is often >65 years, hypothermic, hyporeflexic, hypoglycaemic, bradycardic, coma (reduced GCS) and convulsing.
The patient may have had radio-iodine, thyroidectomy or pituitary surgery (thus causing hypopituitarism). Patients may have seemed psychotic (“myxoedema madness”) just before the coma (e.g. precipitated by infection, MI, stroke or trauma).
What features should be examined in suspected myxoedema coma?
Look for goitre, cyanosis, hypotension (cardiogenic shock), heart failure, and signs of precipitants.
Outline the management of myxoedema coma
The patient should preferably be on ITU.
1) Bloods - T3, T4, TSH, FBC, U&E (Na often decreased), cultures, cortisol and glucose
2) ABG for PaO2 - high flow oxygen if cyanosed, ventilation may be needed
3) Correct any hypoglycaemia
4) Give T3 (liothyronine) 5-20ug/12h IV slowly. Be cautious, you may precipitate features of ischaemic heart disease. Alternative regiments involve levothyroxine.
5) Give hydrocortisone 100mg/8h IV - vital if pituitary hypothyroidism is suspected (i.e. no goitre, no previous radioiodine and no previous thyroid surgery)
6) If infection suspected give IV antibiotics
7) Be careful with fluids, rehydrate as needed but watch for cardiac dysfunction, BP may not respond to fluid and inotropes may be needed
8) Active warming (e.g. blankets, fluids) may be needed for hypothermia. Beware complications (hypolgycaemia, pancreatitis, arrhythmias)
What is hyperthyroid crisis (thyrotoxic storm)?
This is an acute life threatening, hypermetabolic state induced by excessive release of thyroid hormones in individuals with thyrotoxicosis.
What are the signs and symptoms of hyperthyroid crisis?
The clinical presentation includes fever, tachycardia, hypertension, and neurological and GI abnormalities (e.g. acute abdomen, D&V). Hypertension may be followed by congestive heart failure that is associated with hypotension and shock. Because thyroid storm is almost invariably fatal if left untreated, rapid diagnosis and aggressive treatment are critical. Fortunately, this condition is extremely rare in children.
Precipitants include recent thyroid surgery or radioiodine treatment, infection, MI or trauma.
How is thyrotoxic storm diagnosed?
The diagnosis is clinical, so do not wait for test results if urgent treatment is needed. Do TSH, free T4 and free T3. Confirm with technecium uptake if possible.
How should thyrotoxic storm be managed?
The big picture is (i) counteract peripheral effects of thyroid hormones, (ii) inhibit thyroid hormone synthesis and (iii) treat systemic complications
1) IV access, fluids if dehydrated, NB tube if vomiting
2) Take blood for T3, T4, TSH, cultures (if infection suspected)
3) Sedate if necessary (chlorpormazine 50mg PO/IM). Monitor BP
4) If no contraindication and cardiac output ok, give propranolol 40mg/8h. This may need repeating
5) High dose digoxin may be needed to slow the heart, but ensure adequately beta blocked, give with cardiac monitoring
6) Antithyroid drugs - carbimazole 15-25mg/6h PO, after 4h give Lugol’s solution in diluted water to block thyroid
7) Hydrocortisone 100mg/6h IV to prevent peripheral conversion of T4 to T3
8) Treat suspected infection
9) Adjust fluids as necessary, cool with tepid sponging +/- paracetamol
What is an Addisonian crisis? List some signs and symptoms
Addisonian crisis is severe, life threatening adrenal insufficiency caused by low levels of cortisol and aldosterone. Patients may present in shock (tachycardic, vasoconstriction, postural hypotension, oligouria, weak, confused, comatose) - often in a patient with known Addison’s (e.g. when oral steroid has not been increased to cover stress such as pneumonia) or someone on long term steroids who has forgotten their tablets. Remember bilateral adrenal haemorrhage (e.g. meningococcaemia) as a cause. An alternative presentation is with hypoglycaemia.
Outline the management of Addisonian crisis
If suspected, treat before biochemistry is back
1) Bloods for cortisol and ACTH (this needs to go straight to the lab, call ahead); U&Es - can have high L+ (check ECG and give calcium gluconate if needed), and low Na+ (salt depletion should resolve with rehydration and steroids)
2) Hydrocortisone 100mg IV stat
3) IV fluid bolus, crystalloid or colloid to support BP
4) Monitor blood glucose; the danger is hypoglycaemia
5) Blood, urine, sputum for culture then antibiotics if concerned about infection
NB fludrocortisone may well be needed if the problem is adrenal
In what patients would you suspect hypopituitary coma?
Think of decompensated chronic hypophyseal failure whenever hypothermia, refractory hypotension +/- septic signs without fever occur with short stature or loss of axillary/ pubic hair.
It usually develops gradually in a person with known hypopituitarism. If rapid onset due to pituitary infarction (e.g. postpartum Sheehan’s) subarachnoid haemorrhage is often misdiagnosed as symptoms include headache and meningism.
How does hypopituitary coma present?
Headache, ophthalmoplegia, decreased GCS, hypotension, hypothermia, hypoglycaemia, signs of hypopituitarism.
What tests are usually required in hypopituitary coma?
Cortisol, T4, TSH, ACTH, glucose and a pituitary fossa CT/MRI
Outline the management of hypopituitary coma
Treat immediately with hydrocortisone 100mg IV/6h. Only after hydrocortisone has begun can liothyronine be given by slow IV infusion. Prompt surgery may be needed if the cause is pituitary apoplexy.
