1. Airway and Respiratory Support

Airway compromise in thyroid emergencies can arise acutely from altered mentation, central hypoventilation, or significant soft-tissue edema of the tongue and pharynx. Early intubation and implementation of a lung-protective ventilation strategy are associated with reduced mortality.

Indications for Intubation

• Altered Mental Status: Glasgow Coma Scale (GCS) score ≤8.
• Respiratory Failure: Apnea or significant hypoventilation (PaCO₂ >50 mm Hg).
• Airway Obstruction: Stridor or visible edema compromising the airway.
• Refractory Hypoxemia: SpO₂ <90% despite high-flow noninvasive support.

Ventilator and Sedation Strategy

A lung-protective approach is crucial. Initial settings should include a tidal volume of 6 mL/kg of predicted body weight, PEEP of 5–10 cm H₂O, and maintaining a plateau pressure below 30 cm H₂O. For sedation, a propofol infusion allows for rapid titration and neurologic assessments. Benzodiazepines should be minimized, particularly in myxedema coma, due to their prolonged clearance and risk of accumulating.

2. Hemodynamic Management

Hemodynamic profiles differ starkly between the two emergencies. Thyroid storm typically causes a high-output cardiac failure state with vasodilation and tachyarrhythmias, whereas myxedema coma leads to a low-output state with bradycardia, vasoconstriction, and pericardial effusion. Therapy must be tailored accordingly.

3. Temperature Management

Core temperature dysregulation is a hallmark of thyroid emergencies. Active, aggressive cooling is necessary to reduce metabolic stress in thyroid storm, while controlled, gradual rewarming is essential to avoid cardiovascular collapse in myxedema coma.

• Thyroid Storm (Hyperthermia): Initiate active cooling with surface methods like cooling blankets, fans, and evaporative cooling. Administer acetaminophen (650 mg PO/IV every 4 hours) to reset the hypothalamic set point. Avoid ice-cold IV fluids, which can induce shivering and paradoxical vasoconstriction.
• Myxedema Coma (Hypothermia): Begin passive rewarming with blankets in a warm room. The target rate of rewarming is slow and steady: 0.25–0.5 °C per hour. Rapid rewarming with forced-air devices can cause peripheral vasodilation and profound hypotension.

4. ICU-Specific Prophylaxis

Critically ill patients with thyroid emergencies are at high risk for common ICU-acquired complications. Prophylaxis against venous thromboembolism (VTE), stress-related mucosal disease, and infections is a standard component of supportive care.

• VTE Prophylaxis: Use pharmacologic prophylaxis unless a major contraindication exists. Enoxaparin (40 mg SC daily) is preferred for patients with adequate renal function (CrCl >30 mL/min). For those with renal impairment or high bleeding risk, unfractionated heparin (5,000 units SC every 8–12 hours) is a suitable alternative. Intermittent pneumatic compression devices should be added for all, and used alone if anticoagulation is contraindicated.
• Stress Ulcer Prophylaxis: Indicated for patients on mechanical ventilation or those receiving high-dose glucocorticoids. A proton pump inhibitor (e.g., pantoprazole 40 mg IV daily) is the first-line agent.
• Infection Control: Maintain strict hand hygiene. Obtain blood, urine, and sputum cultures early, especially if an infectious trigger is suspected. Initiate empiric broad-spectrum antibiotics promptly and de-escalate based on culture results and clinical response, in line with antimicrobial stewardship principles.

5. Monitoring for Iatrogenic Complications

The therapies used to treat thyroid emergencies, particularly thionamides, carry risks of serious adverse effects. Targeted laboratory and telemetry monitoring is essential for early detection and management of drug-related toxicity.

6. Multidisciplinary Goals of Care

Thyroid emergencies carry high morbidity and mortality, and treatments can be invasive and high-risk. Early and ongoing shared decision-making, facilitated by a multidisciplinary team, is crucial to ensure that care aligns with the patient’s values and prognosis.

• Team Engagement: Actively involve consultants from endocrinology, critical care, pharmacy, and nursing. For complex ethical situations, palliative care and ethics teams provide invaluable support.
• Goals-of-Care Discussions: Proactively discuss prognosis, code status, and patient preferences with the patient or their surrogate decision-maker. These conversations should be revisited as the clinical situation evolves.
• Advanced Therapies: For refractory cases, consider advanced therapies like plasmapheresis, ECMO, or emergent thyroidectomy. These decisions require a careful weighing of risks, benefits, and resource allocation by the entire team.
• Family Involvement: Conduct structured family meetings using clear, lay language to explain the patient’s condition and treatment plan. Ensure all decisions are documented and reflect informed consent.