Endocrinology:: Endocrine Emergencies (Complete)

• Overview: Endocrine Emergencies: At a Glance
• Diabetes: DKA | HHS | Hypoglycaemia
• Adrenal and pituitary: Adrenal Crisis | Pituitary Apoplexy | Phaeochromocytoma Crisis
• Thyroid: Thyroid Storm | Myxoedema Coma
• Electrolytes and other: Calcium Emergencies | Sodium Emergencies | Carcinoid Crisis
• Revision: Drug Reference Table | Spot the Emergency | Exam-style Scenarios | Key Points | Guidelines and Further Reading

🚨 Endocrine emergencies are uncommon but deadly - and most are very treatable if recognised early. This is a quick-reference chapter for the ward: what to recognise and what to do in the first hour. Full background is in each system chapter.
Your four questions for every patient: Is the patient shocked, hypoglycaemic or fitting? Could this be adrenal insufficiency (give hydrocortisone if in doubt)? What do glucose, ketones, sodium, potassium and calcium show? What triggered it?

Endocrine Emergencies: At a Glance

These are short summaries for quick reference on the ward. Full detail is in the diabetes, thyroid, adrenal, pituitary, bone, and sodium and water chapters. Always follow your local protocol and get senior help early.

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DKA

• Diagnosis (JBDS) - all three:
  • Blood ketones of 3.0 mmol/L or more (or urine ketones 2+).
  • Glucose above 11 mmol/L, or known diabetes. Glucose can be normal with SGLT2 inhibitors or in pregnancy.
  • Bicarbonate below 15 mmol/L and/or venous pH below 7.3.
• Fluids:
  • 0.9% saline 1 L over the first hour.
  • If systolic BP is below 90, give 500 mL over 10–15 minutes and repeat.
  • Then replace the deficit over about 24 hours, more cautiously in older people, young adults, pregnancy and heart or kidney failure.
• Insulin:
  • Fixed-rate IV insulin at 0.1 units/kg/hour.
  • Continue long-acting basal insulin.
  • Reduce to 0.05 units/kg/hour when glucose is below 14 mmol/L.
• Potassium:
  • Add 40 mmol/L to fluids if potassium is 3.5–5.5 mmol/L.
  • If below 3.5, senior review - consider more potassium.
  • None if above 5.5.
• Glucose: Add 10% glucose at 125 mL/hour when glucose falls below 14 mmol/L.
• Targets:
  • Ketones fall by at least 0.5 mmol/L per hour.
  • Bicarbonate rises by at least 3 mmol/L per hour.
  • Glucose falls by at least 3 mmol/L per hour.
• Resolution: Ketones below 0.6 mmol/L and pH above 7.3. Switch to subcutaneous insulin with a meal, and stop the IV insulin 30–60 minutes after the first SC dose.

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HHS

• Diagnosis (JBDS):
  • Marked hypovolaemia.
  • Glucose of 30 mmol/L or more.
  • Osmolality of 320 mOsm/kg or more.
  • No significant ketonaemia (below 3.0 mmol/L) or acidosis (pH above 7.3, bicarbonate above 15).
  Usually in older people with type 2 diabetes, developing over days.
• Fluids:
  • 0.9% saline - often 1 L in the first hour, then guided by response.
  • Aim for osmolality to fall by 3–8 mOsm/kg per hour, and sodium by no more than 10 mmol/L in 24 hours.
  • Sodium may rise at first as glucose falls - this is expected if osmolality is falling.
• Insulin:
  • Only start (0.05 units/kg/hour) once glucose stops falling with fluids alone, or earlier if ketones are above 1.0 mmol/L.
  • Aim for glucose to fall by 4–6 mmol/L per hour.
• Other care:
  • Prophylactic LMWH - very high VTE risk.
  • Foot protection - pressure ulcers.
  • Treat the precipitant (often infection).
  • Watch for cerebral oedema, central pontine myelinolysis and fluid overload.

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Hypoglycaemia

• Definition: Glucose below 4.0 mmol/L in diabetes (JBDS). Below 3.0 mmol/L is clinically important.
• Conscious and able to swallow:
  • 15–20 g fast-acting carbohydrate - e.g. 150–200 mL of fruit juice, or 4–5 glucose tablets.
  • Recheck in 10–15 minutes and repeat up to 3 times.
• Confused but able to swallow: Glucose gel squeezed between the teeth and gums.
• Unconscious, fitting or nil by mouth:
  • IV 10% glucose 150–200 mL over 15 minutes (or 20% glucose 75–100 mL).
  • Or glucagon 1 mg IM if there is no IV access. Glucagon is less effective with sulfonylureas, alcohol, liver disease or starvation.
• Once recovered:
  • Give long-acting carbohydrate (a meal or two biscuits).
  • Find the cause.
  • Do not omit insulin in type 1 diabetes - adjust the dose.
• Sulfonylurea-induced hypoglycaemia: Can recur for 24–72 hours. Admit, give a continuous glucose infusion, and consider octreotide.
• Alcohol excess or malnutrition: Give IV thiamine (Pabrinex) with glucose.

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Adrenal Crisis

• Who: Known adrenal insufficiency (primary or secondary), or long-term steroid use, with illness, vomiting, surgery or missed doses. It may be the first presentation of Addison's disease.
• Clinical pattern:
  • Hypotension or shock.
  • Vomiting, abdominal pain.
  • Confusion, collapse.
  • Hyponatraemia, hyperkalaemia (primary).
  • Hypoglycaemia.
• Treat immediately - do not wait for results:
  • Hydrocortisone 100 mg IV or IM.
  • Then 200 mg over 24 hours by continuous infusion (or 50 mg IV/IM 6-hourly).
  • 0.9% saline 1 L over the first hour, then guided by response.
  • Check and treat glucose.
• If not yet diagnosed: Take a sample for cortisol and ACTH before hydrocortisone if it does not cause delay. Do the Synacthen test later.
• Recovery: Treat the precipitant. Taper to double oral doses, then the usual dose.
• Prevention: Sick day rules, a Steroid Emergency Card, and an emergency hydrocortisone injection kit.

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Pituitary Apoplexy

• Mechanism: Sudden haemorrhage into, or infarction of, a pituitary tumour - often previously unknown.
• Clinical pattern:
  • Sudden severe headache ("thunderclap" - a differential of subarachnoid haemorrhage).
  • Vomiting.
  • Visual loss - bitemporal field defect, reduced acuity.
  • Ophthalmoplegia - cranial nerves III, IV and VI in the cavernous sinus.
  • Reduced consciousness.
  • Acute adrenal insufficiency.
• Treatment:
  • Hydrocortisone 100 mg IV, then 50 mg 6-hourly (or 200 mg over 24 hours), after taking blood for cortisol, if this does not delay treatment.
  • Check U&E (sodium), glucose and pituitary hormones.
  • Urgent MRI (CT if MRI is not available).
  • Formal visual fields and acuity.
  • Urgent neurosurgical discussion - surgery for severe or deteriorating vision or consciousness. Otherwise conservative management with close monitoring.
  • Watch for AVP deficiency.

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Phaeochromocytoma Crisis

• Triggers: Surgery, anaesthesia, tumour manipulation, contrast, beta-blockers given alone, glucocorticoids, metoclopramide, tricyclics, pregnancy and labour.
• Clinical pattern:
  • Severe hypertension, or swinging BP with hypotension.
  • Tachyarrhythmias.
  • Headache, sweating, pallor.
  • Pulmonary oedema, catecholamine cardiomyopathy.
  • Stroke, multi-organ failure.
• Treatment (ICU):
  • Alpha-blockade first: IV phentolamine boluses (e.g. 2–5 mg, repeated) or an infusion.
  • Alternatives - IV nicardipine, magnesium sulfate, sodium nitroprusside.
  • Beta-blockade only after alpha-blockade, for tachycardia.
  • Fluids - patients are volume-depleted.
• Before elective surgery: Oral phenoxybenzamine (or doxazosin), titrated, with a high salt and fluid intake, then a beta-blocker.

⚠️ Safety Pearl: Never give a beta-blocker alone to a patient who might have a phaeochromocytoma. Blocking beta-receptors leaves alpha-receptor vasoconstriction unopposed, and can cause a hypertensive crisis.

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Thyroid Storm

• Clinical pattern: Severe, life-threatening thyrotoxicosis, usually triggered by infection, surgery, iodine contrast, childbirth or stopping antithyroid drugs.
  • Fever.
  • Tachycardia or AF, heart failure.
  • Agitation, delirium, coma.
  • Vomiting, diarrhoea, jaundice.
  The Burch–Wartofsky score helps.
• Treatment (ICU or HDU, with endocrinology):
  • Beta-blocker: Propranolol (oral, or IV in small increments) for heart rate and symptoms - care in heart failure.
  • Thionamide: Propylthiouracil preferred, or high-dose carbimazole, to block new hormone synthesis.
  • Iodine (Lugol's iodine or potassium iodide) at least 1 hour after the thionamide, to block hormone release.
  • Hydrocortisone 100 mg IV 6–8-hourly - reduces T4-to-T3 conversion and covers relative adrenal insufficiency.
  • Supportive: Cooling, paracetamol (avoid aspirin, which displaces thyroid hormone from binding proteins), fluids, treat the trigger.

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Myxoedema Coma

• Clinical pattern: Severe decompensated hypothyroidism, usually in an older woman with untreated or undertreated hypothyroidism, triggered by infection, cold, sedatives or stroke.
  • Hypothermia.
  • Reduced consciousness.
  • Bradycardia, hypotension.
  • Hypoventilation - CO2 retention.
  • Hyponatraemia, hypoglycaemia.
  • Pericardial effusion.
• Treatment (ICU):
  • Hydrocortisone 100 mg IV (then 6–8-hourly) before or with thyroid hormone - in case of coexisting adrenal insufficiency.
  • Thyroid hormone: IV liothyronine (T3), started at a low dose and given slowly, especially in older people and those with heart disease. Some centres use levothyroxine per local protocol.
  • Passive rewarming - active rewarming can cause vasodilatation and collapse.
  • Ventilatory support if needed.
  • Glucose. Cautious correction of sodium.
  • Treat infection.
• Prognosis: Mortality is high. Avoid sedatives.

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Calcium Emergencies

• Severe hypercalcaemia (above 3.5 mmol/L, or symptomatic):
  • IV 0.9% saline, typically 4–6 L in 24 hours, guided by heart and kidney function.
  • Stop thiazides, lithium, and calcium and vitamin D supplements.
  • Then zoledronic acid 4 mg IV over 15 minutes, or pamidronate 30–90 mg.
  • Steroids for sarcoidosis, lymphoma or vitamin D excess.
  • Denosumab or dialysis if refractory.
  • Measure PTH to find the cause. Furosemide only for fluid overload after rehydration.
• Severe hypocalcaemia (below about 1.9 mmol/L, tetany, seizures, laryngospasm or ECG changes):
  • 10–20 mL of 10% calcium gluconate in 50–100 mL of 5% glucose IV over 10 minutes, with ECG monitoring.
  • Then an infusion: 100 mL of 10% calcium gluconate in 1 L at 50–100 mL/hour, adjusted to levels.
  • Check and replace magnesium.
  • Start oral calcium and active vitamin D if hypoparathyroid.

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Sodium Emergencies

• Severe symptomatic hyponatraemia (seizures, coma, vomiting, cardiorespiratory distress):
  • 150 mL of 2.7% or 3% saline IV over 15–20 minutes.
  • Recheck sodium at 20 minutes, and repeat (up to 3 doses) until symptoms improve or sodium has risen by 5 mmol/L.
  • Maximum rise: 10 mmol/L in the first 24 hours - 8 mmol/L if at high risk of osmotic demyelination.
  • HDU or ICU care, with sodium checks every 2–4 hours initially.
  • If overcorrecting: 5% glucose, and consider desmopressin with specialist advice.
• Hypernatraemia:
  • Restore circulation with 0.9% saline if shocked.
  • Then replace water (oral, NG or IV 5% glucose), lowering sodium by no more than about 10 mmol/L in 24 hours if chronic.
  • Think of missed desmopressin in AVP deficiency.

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Carcinoid Crisis

• What it is: A sudden massive release of hormones from a NET, causing:
  • Profound hypotension (or hypertension).
  • Flushing.
  • Bronchospasm.
  • Arrhythmias.
  • Altered consciousness.
• Triggers: Anaesthesia, surgery, tumour manipulation, biopsy, embolisation or PRRT, and some drugs.
• Prevention: Octreotide cover before and during procedures in patients with functioning NETs (per local NET protocol - e.g. SC or IV octreotide before induction, then an infusion).
• Treatment:
  • IV octreotide - a bolus (e.g. 500 micrograms) then an infusion (e.g. 50–200 micrograms/hour), titrated.
  • IV fluids.
  • Avoid adrenaline and other catecholamines where possible, because they can trigger further hormone release. Use vasopressin or phenylephrine if pressors are needed, with anaesthetic advice.
  • Treat bronchospasm - avoid adrenaline.

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Drug Reference Table

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Spot the Emergency

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Exam-style Scenarios

1. A 23-year-old with type 1 diabetes has vomiting. Ketones 4.8, pH 7.15, bicarbonate 10, potassium 4.2, glucose 26.
Answer: DKA.

• 0.9% saline 1 L over the first hour.
• Fixed-rate insulin 0.1 units/kg/hour; continue basal insulin.
• Potassium 40 mmol/L in the fluids.
• Add 10% glucose when glucose falls below 14.
• Hourly ketones and glucose; find the trigger.

2. A 68-year-old woman with Addison's disease has gastroenteritis, BP 80/45, sodium 126 and potassium 6.0.
Answer: Adrenal crisis.

• Hydrocortisone 100 mg IV immediately - do not wait for results.
• 0.9% saline 1 L over the first hour.
• Then hydrocortisone 200 mg over 24 hours.
• Check glucose; treat the trigger; review sick day rules.

3. A 55-year-old with a known pituitary macroadenoma has sudden headache, vomiting and double vision.
Answer: Pituitary apoplexy.

• Hydrocortisone 100 mg IV.
• Urgent MRI and visual fields.
• Urgent neurosurgical discussion.
• Check sodium and pituitary hormones.

4. A woman with Graves' disease who stopped carbimazole is febrile, in fast AF and agitated.
Answer: Thyroid storm.

• ICU or HDU.
• Propranolol, propylthiouracil, then iodine at least 1 hour later.
• Hydrocortisone 100 mg IV 6–8-hourly.
• Cooling with paracetamol (not aspirin); treat the trigger.

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Key Points

• If adrenal insufficiency is possible, give hydrocortisone 100 mg - it is cheap, safe and life-saving.
• DKA: fluids, fixed-rate insulin, potassium, and glucose once below 14. Continue basal insulin.
• HHS: fluids first and slowly; insulin only when glucose stops falling; prevent VTE.
• Hypoglycaemia: fast carbohydrate, IV 10% glucose or IM glucagon; thiamine if alcohol or malnutrition.
• Thyroid storm: beta-blocker, propylthiouracil, iodine 1 hour later, hydrocortisone.
• Myxoedema coma: hydrocortisone before thyroid hormone; passive rewarming.
• Never give a beta-blocker alone in suspected phaeochromocytoma.
• Hypercalcaemia: fluids first, then IV bisphosphonate. Hypocalcaemia: IV calcium gluconate with ECG, and check magnesium.
• Severe hyponatraemia: 3% saline boluses, but no more than 10 mmol/L rise in 24 hours.

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Guidelines and Further Reading

• JBDS: Management of diabetic ketoacidosis in adults (2023)
• JBDS: Management of hyperosmolar hyperglycaemic state in adults
• JBDS: Hospital management of hypoglycaemia in adults with diabetes
• Society for Endocrinology: Emergency endocrine guidance (adrenal crisis, hyponatraemia, hypercalcaemia, hypocalcaemia, AVP deficiency)
• Society for Endocrinology / NHS England: Steroid Emergency Card and National Patient Safety Alert (2020)
• UK guidelines for the management of pituitary apoplexy (Society for Endocrinology)
• BNF / BNFc - for current doses

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