Key Points
- Use the highest‑yield diagnostic test early; do not let testing delay time‑critical therapy.
- Set objective targets and reassess frequently.
- Plan definitive source control or disease‑specific therapy when indicated; document follow‑up and patient education.
Algorithm
- Recognize clinical syndrome; draw labs; give IV LT4 (± T3) and hydrocortisone immediately.
- Support airway, ventilation, and hemodynamics; correct electrolytes; treat precipitants.
- Titrate thyroid hormones to labs and clinical response; transition to oral when stable.
Clinical Synopsis & Reasoning
Severe decompensated hypothyroidism with hypothermia, bradycardia, hypotension, and altered mental status. Give IV levothyroxine (± liothyronine), administer stress-dose steroids until adrenal insufficiency excluded, correct precipitating factors, and provide slow rewarming and ventilatory support.
Treatment Strategy & Disposition
Stabilize ABCs. Initiate guideline‑concordant first‑line therapy with precise dosing and continuous monitoring. Escalate to advanced/procedural interventions based on explicit failure criteria. Define ICU, step‑down, and ward disposition triggers; involve specialty teams early.
Epidemiology / Risk Factors
- Risk varies by comorbidity and precipitants; see citations for condition‑specific data.
Investigations
| Test | Role / Rationale | Typical Findings | Notes |
|---|
| TSH/free T4 (do not delay therapy) | Diagnosis | Severe hypothyroid pattern | Supportive |
| ABG, electrolytes, cortisol | Complications/differential | Hypercapnia, hyponatremia, AI | Guide therapy |
| Infection and cardiac evaluation | Precipitants | Sepsis, MI | Treat triggers |
High-Risk & Disposition Triggers
| Trigger | Why it matters | Action |
|---|
| Hypothermia/bradycardia/hypotension | High mortality | ICU; IV LT4 ± T3; hydrocortisone |
| Hypercapnic failure | CO2 narcosis | Ventilatory support |
Pharmacology
| Medication/Intervention | Mechanism | Onset | Role in Therapy | Limitations |
|---|
| Levothyroxine 200–400 µg IV load then 50–100 µg IV daily (± Liothyronine 5–10 µg IV q8–12 h) | Hormone replacement | Hours | Core therapy | Lower doses in elderly/cardiac disease |
| Hydrocortisone 100 mg IV q8h | Glucocorticoid | Hours | Covers relative AI | Stop when AI excluded |
| Gentle rewarming, ventilatory/hemodynamic support | Supportive | Hours | Prevent arrhythmias/collapse | Avoid rapid warming |
Prognosis / Complications
- Outcome depends on timeliness of diagnosis and definitive therapy; monitor for complications.
Patient Education / Counseling
- Provide red‑flag education, adherence guidance, and explicit return precautions; arrange timely specialty follow‑up.
References
- ATA/Emergency thyroid management statements — Link