Thyroid Emergencies

Introduction

Thyroid emergencies—thyroid storm and myxoedema coma—are rare but often fatal endocrine crises. For prehospital clinicians and Allied Health Professionals (AHPs), their subtle onset and overlap with common presentations such as sepsis, arrhythmia, or hypothermia make recognition challenging. Yet, these conditions demand rapid suspicion, supportive management, and urgent hospital conveyance.

Mortality rates exceed 20–60% without treatment (Popoveniuc et al., 2014). These emergencies are under-recognised in emergency and prehospital care settings and warrant greater focus in differential diagnosis, clinical reasoning, and structured education.

Case Study: The Clue Is in the Cold

A 72-year-old woman is found at home, confused, bradycardic, hypothermic (32.8°C), and hypotensive. ECG shows sinus bradycardia with low QRS voltage. Blood glucose is low-normal. She’s slow to respond but breathing independently.

Initial impressions may include stroke or sepsis. However, following paramedic concern and prompt handover, she is admitted and diagnosed with myxoedema coma. She survives because a rare differential was considered in the field.

Why This Matters

Both thyroid storm (extreme hyperthyroidism) and myxoedema coma (severe hypothyroidism) mimic more common critical conditions:

Sepsis, delirium, arrhythmias, heatstroke, Sepsis, stroke, hypothermia and adrenal crisis

NICE Guideline NG145 (2019) recommends clinicians consider thyroid dysfunction in cases of undifferentiated altered mental states, especially in the elderly or those with existing thyroid conditions.

Thyroid Storm: Clues in the Chaos

Thyroid storm is a hypermetabolic crisis, often triggered by:

• Infection

• Myocardial infarction

• Surgery or trauma

• Non-compliance with antithyroid medications

Key Signs:

• Fever > 38.5°C

• Agitation or delirium

• Tachycardia (often >130 bpm), with or without atrial fibrillation

• Gastrointestinal upset: diarrhoea, vomiting

• Pulmonary oedema or heart failure

Burch-Wartofsky Point Scale: A score >45 suggests thyroid storm likelihood (Burch & Wartofsky, 1993).

Key parameters assessable prehospitally include:

Parameter Points

Temperature Up to 30

CNS disturbance Up to 30

GI-hepatic dysfunction Up to 20

Tachycardia Up to 25

Precipitating event Up to 10

TSH is typically suppressed with elevated free T3/T4, but prehospital diagnosis must be clinical. Delay in treatment may be fatal (Nayak & Burman, 2006).

Myxoedema Coma: When Cold Means Crisis

Often affecting elderly hypothyroid women in cold environments, myxoedema coma is marked by:

• Hypothermia (<35°C)

• Reduced consciousness (confusion, stupor, coma)

• Bradycardia and hypotension

Other Features:

• Non-pitting oedema

• Macroglossia

• Dry skin, slow reflexes

• Hoarse voice

• Hyponatraemia and hypoglycaemia

• ECG: sinus bradycardia, low voltage QRS, possible heart block

Precipitating factors include infections, cold exposure, and sedatives (Jonklaas et al., 2014).

Prehospital Actions That Save Lives

Clinical Rationale: Identify red flags -

Pattern recognition amid non-specific symptoms.

Avoid misattribution Sepsis, stroke, and adrenal crisis are mimics

Supportive care

Oxygenation, warming, glucose, IV access,

Early conveyance

Time-critical endocrine emergency

Clear handover communication

Raise concern for endocrine crisis to ED team

Clinical Evidence

• Popoveniuc et al. (2014): Myxoedema coma mortality ranges 30–60% and requires high suspicion.

• Nayak & Burman (2006): Early diagnosis and empiric treatment improve survival in thyroid storm.

• NICE NG145 (2019): Supports endocrine screening in unexplained acute deterioration.

• Jonklaas et al. (2014): ATA guidelines stress prompt supportive therapy and hormone replacement.

References

• Burch, H.B. & Wartofsky, L. (1993). Life-threatening thyrotoxicosis. Endocrinology and Metabolism Clinics of North America, 22(2), 263–277.

• Jonklaas, J., Bianco, A.C., Bauer, A.J., et al. (2014). Guidelines for the treatment of hypothyroidism: prepared by the American Thyroid Association task force. Thyroid, 24(12), 1670–1751.

• Nayak, B. & Burman, K. (2006). Thyrotoxic crisis. Endocrinology and Metabolism Clinics of North America, 35(4), 663–676.

• NICE. (2019). Thyroid disease: assessment and management (NG145). https://www.nice.org.uk/guidance/ng145

• Popoveniuc, G., et al. (2014). Myxedema coma: diagnosis and treatment. Endocrinology and Metabolism Clinics, 43(2), 387–403.

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