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Myxedema Coma

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MYXEDEMA COMA – EMERGENCY PROTOCOL

CLINICAL MANAGEMENT GUIDELINE – INDIA

🚨 MEDICAL EMERGENCY | ICU ADMISSION REQUIRED

Mortality: 20-60% even with optimal treatment

This is a CLINICAL diagnosis – Do NOT wait for lab confirmation

Note: ”Myxedema coma“ is a misnomer – Many patients are NOT comatose

🔰 SYMBOL LEGEND

Symbol	Meaning
🚨	Emergency / Critical
✅	Recommended / First-line
⚠️	Caution / Important
❌	Contraindicated / Avoid
💊	Drug
🇮🇳	India-specific
⏱️	Time-critical

SECTION 1: RECOGNITION

1.1 DEFINITION

🚨 Myxedema Coma = Life-threatening, decompensated severe hypothyroidism with multi-organ dysfunction, characterized by:

- Altered mental status (confusion to coma)
- Hypothermia
- Precipitating event

📌 NOT just severe hypothyroidism – It is end-stage decompensation with systemic failure

1.2 CARDINAL FEATURES

🚨 Feature	Description
Altered mental status	Lethargy → Confusion → Obtundation → Coma
Hypothermia	< 35°C (may be normothermic if concurrent infection)
Precipitating event	Almost ALWAYS identifiable – Search for it
Hypoventilation	Hypoxia, Hypercapnia, Respiratory failure
Cardiovascular depression	Bradycardia, Hypotension

1.3 PRECIPITANTS – ALWAYS SEARCH FOR THE TRIGGER

🚨 Common Precipitants

Infection (most common) – Pneumonia, UTI, Sepsis

Cold exposure

Medications – Sedatives, Opioids, Anesthetics, Lithium, Amiodarone

Stroke / MI

Trauma / Surgery

GI bleeding

Non-compliance with levothyroxine

Metabolic – Hypoglycemia, Hyponatremia, Hypoxia, Hypercapnia

Heart failure

1.4 RISK FACTORS

Risk Factor

Elderly women (most common demographic)

Undiagnosed / Untreated hypothyroidism

Non-compliance with thyroid hormone replacement

Recent discontinuation of levothyroxine

Winter months (cold exposure)

Institutionalized patients

1.5 UNDERLYING CAUSES OF HYPOTHYROIDISM

Primary (95%)	Central (5%)
Autoimmune (Hashimoto’s)	Pituitary tumor/surgery/radiation
Post-thyroidectomy	Sheehan syndrome
Post-radioactive iodine	Hypophysitis
Iodine deficiency 🇮🇳	Hypothalamic disease
Drug-induced (Lithium, Amiodarone)

SECTION 2: CLINICAL FEATURES

2.1 SYSTEMIC MANIFESTATIONS

Neurological

Feature	Notes
Altered mental status	Ranges from lethargy to frank coma
Confusion / Disorientation
Psychosis	”Myxedema madness“
Seizures	May occur
Delayed relaxation of reflexes	”Hung-up“ reflexes – Pathognomonic
Hyporeflexia	Or areflexia
Cerebellar signs	Ataxia

Cardiovascular

Feature	Mechanism
Bradycardia	↓ Chronotropy; Often < 60 bpm
Hypotension	↓ Cardiac output; ↓ SVR response
Cardiomegaly	Pericardial effusion; Dilated cardiomyopathy
Pericardial effusion	Common; Rarely causes tamponade
Heart failure	Low output state
ECG changes	Low voltage, Bradycardia, Prolonged QT, Flattened T waves, Heart block

Respiratory

Feature	Mechanism
Hypoventilation	↓ Hypoxic and hypercapnic drive
Hypoxia	Alveolar hypoventilation; Pleural effusion
Hypercapnia	Respiratory muscle weakness
Respiratory failure	May require intubation
Pleural effusion	Common
Upper airway obstruction	Macroglossia; Laryngeal edema

Thermoregulation

Feature	Notes
Hypothermia	Core temp < 35°C; May be < 32°C
May be normothermic	If concurrent infection
Absence of shivering	Thermoregulatory failure

Gastrointestinal

Feature	Notes
Ileus / Constipation	↓ GI motility
Abdominal distension	May mimic obstruction
Gastric atony
Megacolon	Rare
GI bleeding	May be precipitant
Ascites	Uncommon

Renal / Electrolyte

Feature	Mechanism
Hyponatremia	↓ Free water excretion (↑ ADH); Dilutional
Oliguria	↓ Renal perfusion
Elevated creatinine	Prerenal; Rhabdomyolysis
Bladder atony	Urinary retention

Dermatological

Feature	Notes
Non-pitting edema (Myxedema)	Face, Hands, Feet
Periorbital puffiness
Dry, cool, doughy skin
Coarse, brittle hair
Loss of outer eyebrows	Queen Anne’s sign
Pallor / Yellow tint	Carotenemia
Macroglossia	May obstruct airway

Hematological

Feature	Notes
Anemia	Normocytic or Macrocytic
Coagulopathy	Acquired von Willebrand syndrome
Bleeding tendency

2.2 CLINICAL PRESENTATION PATTERNS

Classic Presentation

Features

Elderly woman

Found unresponsive or confused

Hypothermia

Bradycardia

History of thyroid disease or thyroidectomy

Winter months

Atypical Presentation

Features

Normothermic (if infection present)

Not comatose (just confused/lethargic)

No prior thyroid history (undiagnosed)

Younger patients (rare)

2.3 PHYSICAL EXAMINATION CHECKLIST

System	Look For
General	Hypothermia, Obtundation, Non-pitting edema
Vitals	Bradycardia, Hypotension, Hypothermia, Bradypnea
HEAD	Periorbital edema, Macroglossia, Coarse hair
Neck	Thyroidectomy scar, Goiter (may be absent)
CV	Bradycardia, Distant heart sounds (effusion), JVP elevated
Resp	Decreased breath sounds (effusion), Hypoventilation
Abdomen	Distension, Absent bowel sounds (ileus), Ascites
Neuro	↓ GCS, Delayed reflexes (”hung-up“), Hyporeflexia, Seizures
Skin	Dry, Cool, Doughy, Non-pitting edema, Pallor
Extremities	Non-pitting edema

SECTION 3: DIAGNOSIS

3.1 CLINICAL DIAGNOSIS

🚨 Key Principle

Myxedema coma is a CLINICAL diagnosis

Do NOT wait for lab confirmation to initiate treatment

High clinical suspicion + Supportive features → TREAT IMMEDIATELY

Diagnostic Criteria (Clinical)

Criteria

Altered mental status (confusion to coma)

PLUS History/features of hypothyroidism

PLUS Precipitating event

PLUS Hypothermia and/or Hypoventilation and/or Hypotension

3.2 LABORATORY FINDINGS

Thyroid Function Tests

Test	Expected Finding
TSH	↑↑ Markedly elevated (Primary)
	↓ or Inappropriately normal (Central)
FT4	↓↓ Very low
FT3	↓ Low (less reliable in sick patients)
T3	Often very low

Primary vs Central Hypothyroidism

	TSH	FT4
Primary	↑↑ (often > 50-100)	↓↓
Central	↓ or Normal	↓↓

📌 If TSH is low/normal with low FT4 → Suspect central hypothyroidism → Check cortisol BEFORE giving levothyroxine

3.3 OTHER LABORATORY ABNORMALITIES

Test	Finding	Mechanism
Sodium	↓ Hyponatremia	↑ ADH; ↓ Free water clearance
Glucose	↓ Hypoglycemia	↓ Gluconeogenesis; Adrenal insufficiency
Cortisol	Should be checked	Rule out concomitant adrenal insufficiency
CBC	Anemia (Normocytic/Macrocytic)
CK	↑↑ Elevated	Myopathy; Rhabdomyolysis
LDH	↑ Elevated
Cholesterol	↑ Elevated	↓ LDL receptor expression
Creatinine	↑ Elevated	Prerenal; Rhabdomyolysis
Liver enzymes	May be elevated
ABG	Hypoxia, Hypercapnia	Hypoventilation
Lactate	May be elevated	Hypoperfusion

3.4 ADDITIONAL INVESTIGATIONS

Investigation	Purpose
ECG	Bradycardia, Low voltage, Long QT, Heart block, ST-T changes
CXR	Cardiomegaly, Pleural effusion, Pneumonia
Echocardiogram	Pericardial effusion, LV dysfunction
Blood cultures	Infection workup
Urine analysis/culture	UTI
CT Head	If CNS cause suspected (stroke)
Cortisol (Random)	Rule out adrenal insufficiency
Lumbar puncture	If meningitis suspected (↑ protein, Normal cell count in myxedema)

3.5 CORTISOL – CRITICAL ASSESSMENT

🚨 MUST CHECK CORTISOL

Adrenal insufficiency may coexist (Schmidt syndrome / APS-2)

Hypothyroidism masks adrenal insufficiency

Giving levothyroxine increases cortisol metabolism

Levothyroxine without cortisol replacement can precipitate adrenal crisis

Action

Draw cortisol level BEFORE or WITH first dose of levothyroxine

Give empiric glucocorticoids until adrenal insufficiency excluded

SECTION 4: MANAGEMENT – OVERVIEW

4.1 TREATMENT PRINCIPLES

🚨 MYXEDEMA COMA MANAGEMENT

┌─────────────────────────────────────────────────────────────┐

│ STEP 1: ICU ADMISSION + SUPPORTIVE CARE │

│ (Airway, Passive warming, Fluids, Monitoring) │

└─────────────────────────────────────────────────────────────┘

│

▼

┌─────────────────────────────────────────────────────────────┐

│ STEP 2: GLUCOCORTICOID THERAPY │

│ 💊 Hydrocortisone 100 mg IV │

│ ⚠️ GIVE BEFORE OR WITH LEVOTHYROXINE │

└─────────────────────────────────────────────────────────────┘

│

▼

┌─────────────────────────────────────────────────────────────┐

│ STEP 3: THYROID HORMONE REPLACEMENT │

│ 💊 Levothyroxine IV (preferred) or PO/NG │

│ ± 💊 Liothyronine (T3) in severe cases │

└─────────────────────────────────────────────────────────────┘

│

▼

┌─────────────────────────────────────────────────────────────┐

│ STEP 4: TREAT PRECIPITANT │

│ (Infection, Cold exposure, etc.) │

└─────────────────────────────────────────────────────────────┘

│

▼

┌─────────────────────────────────────────────────────────────┐

│ STEP 5: CORRECT METABOLIC ABNORMALITIES │

│ Hyponatremia, Hypoglycemia │

└─────────────────────────────────────────────────────────────┘

│

▼

┌─────────────────────────────────────────────────────────────┐

│ STEP 6: MONITORING AND ONGOING CARE │

└─────────────────────────────────────────────────────────────┘

4.2 ⚠️ CRITICAL TREATMENT SEQUENCE

🚨 MUST FOLLOW THIS ORDER

GLUCOCORTICOIDS FIRST (or WITH) → THEN Levothyroxine

Levothyroxine increases cortisol metabolism

If undiagnosed adrenal insufficiency present → Adrenal crisis

Give hydrocortisone BEFORE or SIMULTANEOUSLY with levothyroxine

SECTION 5: STEP-BY-STEP MANAGEMENT

STEP 1: ICU ADMISSION AND SUPPORTIVE CARE

5.1 Airway and Breathing

Action

Assess airway – Macroglossia, Laryngeal edema may obstruct

Intubate if: GCS ≤ 8, Respiratory failure, Hypercapnia (PCO2 > 50), Unable to protect airway

Supplemental oxygen

Mechanical ventilation if intubated

⚠️ Caution: Increased sensitivity to sedatives – Use reduced doses

5.2 Rewarming – PASSIVE WARMING ONLY

🚨 Rewarming Strategy

PASSIVE warming only: Blankets, Warm environment, Cover head

❌ AVOID active external rewarming (heating blankets, warm baths)

Active warming causes peripheral vasodilation → Cardiovascular collapse

Core temperature should rise 0.5-1°C per hour with thyroid hormone replacement

5.3 IV Access and Fluids

Fluid Management

Establish IV access

Cautious IV fluids – Patients are often euvolemic/hypervolemic

Hyponatremia is dilutional – Fluid restriction often needed

If hypotensive: Judicious 0.9% Normal Saline

If hypoglycemic: Dextrose-containing fluids (D5NS, D10)

⚠️ Avoid free water – Worsens hyponatremia

⚠️ Avoid rapid sodium correction – Risk of osmotic demyelination

5.4 Monitoring

Parameter	Frequency
Heart rate / Rhythm	Continuous
Blood pressure	Continuous
Temperature (core)	q1-2 hours
SpO2	Continuous
Respiratory rate	Continuous
Urine output	Hourly
GCS / Mental status	q1-2 hours
Glucose	q2-4 hours
Electrolytes (Na+)	q6-12 hours initially
ABG	q6-12 hours if ventilated

5.5 Hemodynamic Support

If Hypotensive

Cautious IV fluids (avoid overload)

Vasopressors if refractory (Noradrenaline preferred)

⚠️ May be resistant to vasopressors until thyroid hormone repleted

Hypotension often improves with hormone replacement

STEP 2: GLUCOCORTICOID THERAPY

5.6 Rationale

🚨 Why Glucocorticoids?

Concomitant adrenal insufficiency – May coexist (APS-2)

Relative adrenal insufficiency – In critical illness

Levothyroxine increases cortisol clearance – May precipitate adrenal crisis

Give empirically – Do NOT wait for cortisol results

Can be tapered/stopped once adrenal insufficiency excluded

5.7 Drug and Dose

💊 Drug	Dose	Timing
Hydrocortisone ✅	100 mg IV bolus	BEFORE or WITH levothyroxine
	Then 50-100 mg IV q8h
	OR 200 mg/24h continuous infusion

Duration

Continue until:

• Adrenal insufficiency excluded (cortisol results)

• Patient stabilized

• If adrenal insufficiency confirmed → Continue/transition to maintenance

If excluding AI → Taper over 3-5 days once stable

STEP 3: THYROID HORMONE REPLACEMENT

5.8 Goals

Goal

Rapid restoration of thyroid hormone

But NOT too rapid → Risk of arrhythmias, MI, especially in elderly/cardiac disease

Balance urgency of replacement with cardiovascular safety

5.9 Treatment Options

Strategy	Description	Use
Levothyroxine (T4) only	Loading + Maintenance	✅ Most common
Levothyroxine + Liothyronine (T4 + T3)	Combination	Severe cases; Controversial
Liothyronine (T3) only	Faster onset	Rarely used alone; More cardiac risk

5.10 OPTION A: IV LEVOTHYROXINE (Preferred if Available)

💊 Levothyroxine IV

Loading dose:200-400 μg IV (or 200-500 μg in severe cases)

Maintenance:50-100 μg IV daily

Switch to oral when patient stable and absorbing

Lower Dose in High-Risk Patients

⚠️ Use Lower Loading Dose (100-200 μg) If:

Age > 60-65 years

Known coronary artery disease

History of arrhythmias

History of heart failure

Small body size

5.11 OPTION B: ORAL/NG LEVOTHYROXINE (If IV Unavailable)

💊 Levothyroxine PO/NG

Loading dose:300-500 μg PO/NG

Maintenance:50-100 μg PO/NG daily

⚠️ GI absorption impaired in myxedema coma (ileus, edema)

Use higher doses to compensate for reduced absorption

5.12 OPTION C: COMBINATION T4 + T3

Rationale

T3 has faster onset of action (hours vs days for T4)

T4→T3 conversion impaired in critical illness

May provide more rapid clinical improvement

BUT Higher cardiac risk with T3

💊 Combination Regimen

Levothyroxine: 200-300 μg IV/PO loading → 50-100 μg daily

PLUS

Liothyronine: 10-20 μg IV/PO loading → 5-10 μg q8-12h

⚠️ Liothyronine Cautions

Higher arrhythmia risk

Higher MI risk

Use with extreme caution in elderly/cardiac patients

Consider omitting T3 in high-risk patients

5.13 INDIA – PRACTICAL APPROACH

Availability

IV Levothyroxine – Limited availability; May not be accessible

Oral Levothyroxine – Widely available (Eltroxin, Thyronorm, Thyrox)

IV Liothyronine (T3) – NOT available in India

Oral Liothyronine – Limited availability

Practical Protocol

Use oral/NG levothyroxine in higher doses

Hydrocortisone – Available IV

Focus on: Supportive care + Glucocorticoids + Oral T4 + Treat precipitant

5.14 THYROID HORMONE DOSING SUMMARY

Parameter	IV Available	IV NOT Available 🇮🇳
LT4 Loading	200-400 μg IV	300-500 μg PO/NG
LT4 Maintenance	50-100 μg IV daily	75-100 μg PO/NG daily
T3 Loading	10-20 μg IV (if severe)	10-20 μg PO (if available)
T3 Maintenance	5-10 μg q8-12h	5-10 μg q8-12h
T3 Caution	⚠️ Cardiac risk	⚠️ Cardiac risk

STEP 4: TREAT THE PRECIPITANT

5.15 Identify and Treat

Precipitant	Treatment
Infection	Empiric antibiotics → Culture-directed; Source control
Cold exposure	Passive rewarming; Remove from cold
Sedatives/Opioids	Reversal agents if appropriate; Avoid further sedation
Hypoglycemia	IV dextrose
GI bleeding	Transfusion; Endoscopy; PPI
MI/Stroke	Specific management
Non-compliance	Resume thyroid hormone

Empiric Antibiotics (If Infection Suspected)

Setting	Regimen
Pneumonia	Ceftriaxone + Azithromycin
UTI	Ceftriaxone or Fluoroquinolone
Sepsis/Unknown source	Piperacillin-tazobactam or Meropenem
Adjust based on cultures

STEP 5: CORRECT METABOLIC ABNORMALITIES

5.16 Hyponatremia

Mechanism

Dilutional – Impaired free water excretion (↑ ADH)

NOT due to sodium loss

Management

Mild (Na > 120): Fluid restriction; Will correct with thyroid hormone

Moderate (Na 110-120): Fluid restriction; Consider hypertonic saline if symptomatic

Severe (Na < 110) or Symptomatic:3% Hypertonic saline – Cautious

⚠️ Avoid rapid correction – Risk of osmotic demyelination syndrome

Target: < 8-10 mEq/L increase in 24 hours

< 18 mEq/L increase in 48 hours

5.17 Hypoglycemia

Management

IV Dextrose (D25 or D50) bolus if symptomatic

Dextrose-containing maintenance fluids (D5NS, D10)

Monitor glucose q2-4 hours

Consider adrenal insufficiency if hypoglycemia persists

5.18 Anemia

Management

Usually does not require transfusion

Will improve with thyroid hormone replacement

Transfuse only if: Hemodynamically significant, Ongoing bleeding, Severe anemia (Hb < 7)

STEP 6: MONITORING AND ONGOING CARE

5.19 Clinical Monitoring

Parameter	Target/Frequency
Temperature	Rising 0.5-1°C/hour initially; q1-2h monitoring
Heart rate	Gradual increase expected; Watch for arrhythmias
Blood pressure	Stabilization expected; Continuous monitoring
Mental status	Improvement over 24-72 hours
Respiratory	Improvement; Potential for extubation
Urine output	> 0.5 mL/kg/hr

5.20 Laboratory Monitoring

Test	Frequency
TSH, FT4	Baseline; Then q24-48h initially
Sodium	q6-12h initially; Then daily
Glucose	q2-4h initially
Cortisol	Baseline (before hydrocortisone ideally)
ABG	If ventilated; q6-12h
Renal function, Electrolytes	Daily

5.21 Expected Response to Treatment

Time	Expected Improvement
12-24 hours	Temperature begins to rise
24-48 hours	Heart rate improving; Mental status improving
48-72 hours	Significant clinical improvement
3-7 days	Marked improvement; May extubate if intubated
TSH normalization	May take weeks

SECTION 6: DRUG DOSES – QUICK REFERENCE

6.1 TREATMENT PROTOCOL AT A GLANCE

Step	Drug	Dose	Notes
1	Supportive	Passive warming, Cautious fluids, Monitoring	ICU admission
2	💊 Hydrocortisone	100 mg IV bolus → 50-100 mg q8h	🚨 GIVE FIRST / WITH LT4
3a	💊 Levothyroxine IV	200-400 μg IV load → 50-100 μg/day	If IV available
3b	💊 Levothyroxine PO/NG	300-500 μg load → 75-100 μg/day	🇮🇳 If IV unavailable
3c	💊 Liothyronine (T3)	10-20 μg load → 5-10 μg q8-12h	Optional; Severe cases; ⚠️ Cardiac risk
4	Treat Precipitant	Antibiotics, etc.	Search for and treat
5	Correct Metabolic	Hyponatremia: Fluid restrict; Hypoglycemia: Dextrose

6.2 DOSE ADJUSTMENTS FOR HIGH-RISK PATIENTS

Risk Factor	LT4 Loading Dose
Age < 60, No cardiac disease	300-400 μg IV (400-500 μg PO)
Age > 60	200-300 μg IV (300-400 μg PO)
Known CAD / Arrhythmias / HF	100-200 μg IV (200-300 μg PO)
Elderly + Cardiac disease	100-150 μg IV (200 μg PO)
⚠️ Avoid T3 in cardiac patients

6.3 DRUGS TO AVOID

❌ Drug/Action	Reason
Active rewarming	Causes vasodilation → Cardiovascular collapse
Sedatives/Opioids	Increased sensitivity; Respiratory depression
Levothyroxine WITHOUT glucocorticoids	May precipitate adrenal crisis
Rapid sodium correction	Risk of osmotic demyelination
Excessive IV fluids	Worsens hyponatremia; Fluid overload

SECTION 7: SPECIAL SITUATIONS

7.1 MYXEDEMA COMA WITH ADRENAL INSUFFICIENCY

Suspect If

Clues

Refractory hypotension despite fluids and thyroid hormone

Severe hypoglycemia

History of autoimmune disease

Known pituitary disease (central hypothyroidism)

Low cortisol level

Management

Action

Continue glucocorticoids (do not taper)

Check baseline cortisol, ACTH

Once stable: ACTH stimulation test

If confirmed: Long-term glucocorticoid (± mineralocorticoid) replacement

7.2 MYXEDEMA COMA WITH CENTRAL HYPOTHYROIDISM

Recognition

Feature

TSH low or normal (inappropriately) with Low FT4

History of pituitary disease, Surgery, Radiation, Trauma

Other pituitary hormone deficiencies

Management

Difference

Higher likelihood of adrenal insufficiency

⚠️ Give glucocorticoids FIRST – Even more critical

Once stable: Assess other pituitary axes

MRI pituitary when stable

7.3 MYXEDEMA COMA IN PREGNANCY

Key Points

Consideration

Very rare (hypothyroidism causes anovulation)

High fetal mortality

Levothyroxine safe – Essential for fetal development

Hydrocortisone safe

Obstetric involvement essential

7.4 MYXEDEMA COMA WITH CARDIAC COMPLICATIONS

Pericardial Effusion

Management

Usually resolves with thyroid hormone replacement

Rarely causes tamponade

Pericardiocentesis only if hemodynamically significant tamponade

Arrhythmias / Cardiac Ischemia

Management

Use lower doses of levothyroxine

Avoid T3 if possible

Careful monitoring

Treat standard cardiac management as needed

7.5 MYXEDEMA COMA WITH RESPIRATORY FAILURE

Management

Action

Intubation and mechanical ventilation if needed

⚠️ Increased sensitivity to sedatives – Use reduced doses

Slow weaning – May take days to weeks

Treat underlying pneumonia if present

SECTION 8: COMPLICATIONS

8.1 COMPLICATIONS OF MYXEDEMA COMA

Complication	Management
Respiratory failure	Intubation; Mechanical ventilation
Cardiovascular collapse	Vasopressors; Careful fluid management
Arrhythmias	Monitoring; Reduce T4/T3 dose; Standard management
MI	Reduce thyroid hormone dose; Cardiology input
Seizures	Benzodiazepines; Correct hyponatremia
Rhabdomyolysis	IV fluids; Monitor CK and renal function
Ileus / Megacolon	NG decompression; Will resolve with treatment
Bleeding	Transfusion if needed; Will improve with treatment
Infection	Antibiotics; Source control
Osmotic demyelination	Avoid rapid sodium correction

8.2 COMPLICATIONS OF TREATMENT

Complication	Prevention
Adrenal crisis	Give glucocorticoids BEFORE/WITH levothyroxine
Cardiac arrhythmias	Use lower doses in elderly/cardiac patients; Avoid T3
Myocardial infarction	Lower doses; Slow replacement
Osmotic demyelination	Slow sodium correction
Cardiovascular collapse from rewarming	Passive warming only

SECTION 9: PROGNOSIS

9.1 MORTALITY

Factor	Impact
Overall mortality	20-60% (even with treatment)
Untreated	Nearly 100% fatal
With optimal treatment	20-30% mortality

9.2 PROGNOSTIC FACTORS

Poor Prognostic Indicators

Factor

Advanced age

Severe hypothermia (< 32°C)

Severe bradycardia

Hypotension

Coma (lower GCS)

Need for mechanical ventilation

Sepsis

High APACHE score

Delayed treatment

Multi-organ failure

Cardiovascular complications

Better Prognosis If

Factor

Younger age

Early recognition and treatment

Mild hypothermia

Higher GCS

Identifiable and treatable precipitant

SECTION 10: PREVENTION

10.1 PREVENTING MYXEDEMA COMA

Strategy

Ensure compliance with levothyroxine

Patient education – Never stop thyroid medication suddenly

Regular thyroid monitoring in hypothyroid patients

Dose adjustment in elderly, Cardiac patients

Stress dose adjustment during illness/surgery

Identify and treat hypothyroidism early

Avoid sedatives/opioids in uncontrolled hypothyroidism

Educate on symptoms of hypothyroidism

10.2 PATIENT EDUCATION

Teaching Point

Take levothyroxine daily; Do NOT stop

Take on empty stomach, Same time daily

Regular follow-up and TSH monitoring

Recognize symptoms of hypothyroidism

Seek medical attention if unwell

Inform all healthcare providers about thyroid condition

SECTION 11: INDIA-SPECIFIC CONSIDERATIONS

11.1 DRUG AVAILABILITY

Drug	Availability	Notes
Levothyroxine oral	✅ Widely available	Eltroxin, Thyronorm, Thyrox, Lethyrox
Levothyroxine IV	⚠️ Limited	May need import; Not routinely stocked
Liothyronine (T3) oral	⚠️ Limited	Available but not common
Liothyronine (T3) IV	❌ Not available
Hydrocortisone IV	✅ Available	Widely available
Dexamethasone IV	✅ Available	Alternative if hydrocortisone unavailable

11.2 PRACTICAL PROTOCOL FOR INDIA

Step	Action
1	ICU admission; Supportive care; PASSIVE warming only
2	💊 Hydrocortisone 100 mg IV → 50-100 mg q8h
3	💊 Levothyroxine 300-500 μg via NG tube (crush tablets) → 75-100 μg daily
4	If severe/no response: Add 💊 Oral T3 10 μg q8h (if available)
5	Treat precipitant (especially infection)
6	Correct hyponatremia (fluid restriction); Correct hypoglycemia (dextrose)
7	Monitor closely; Transfer to higher center if needed

11.3 CHALLENGES AND SOLUTIONS

Challenge	Solution
IV levothyroxine unavailable	Use oral/NG in higher doses
Delayed presentation	High index of suspicion; Early treatment
Undiagnosed hypothyroidism	Screen high-risk patients
Limited ICU access	Early recognition; Supportive care; Refer early
Cold exposure in winter	Patient education; Home heating

SECTION 12: SUMMARY TABLES

12.1 DIAGNOSTIC CRITERIA

Feature	Present
Altered mental status	☐
Hypothermia (< 35°C)	☐
Features of hypothyroidism	☐
Precipitating event	☐
TSH elevated (Primary) OR Low/Normal (Central)	☐
FT4 low	☐
If ≥ 4 features → High suspicion for Myxedema Coma

12.2 TREATMENT SEQUENCE

Order	Intervention	Timing
1	ICU + Supportive care	Immediate
2	Hydrocortisone 100 mg IV	BEFORE or WITH LT4
3	Levothyroxine (IV or PO/NG)	After/With hydrocortisone
4	± Liothyronine (T3)	If severe; With caution
5	Treat precipitant	Immediate
6	Correct metabolic abnormalities	Ongoing

12.3 LEVOTHYROXINE DOSING

Patient Category	IV Loading	PO/NG Loading	Maintenance
Younger, No cardiac	300-400 μg	400-500 μg	100 μg/day
Older (> 60)	200-300 μg	300-400 μg	75-100 μg/day
Cardiac disease	100-200 μg	200-300 μg	50-75 μg/day
Elderly + Cardiac	100-150 μg	200 μg	50 μg/day

12.4 CLINICAL RESPONSE TIMELINE

Time	Expected Response
12-24 hours	Temperature rising
24-48 hours	HR improving; Mentation improving
48-72 hours	Significant clinical improvement
3-7 days	Marked improvement; Extubation possible
Weeks	TSH normalization

12.5 KEY DIFFERENCES: MYXEDEMA COMA VS THYROID STORM

Feature	Myxedema Coma	Thyroid Storm
Underlying disorder	Hypothyroidism	Hyperthyroidism
Temperature	Hypothermia	Hyperthermia
Heart rate	Bradycardia	Tachycardia
Mental status	Lethargy → Coma	Agitation → Coma
TSH	↑↑ (Primary) or ↓/N (Central)	↓↓ Suppressed
FT4	↓↓	↑↑
Thyroid hormone	Give (replace)	Block (stop synthesis)
Glucocorticoids	Give (before/with T4)	Give (blocks T4→T3)
Beta-blockers	Usually not needed	Essential
Iodine	Not indicated	Give (after ATD)
Rewarming	Passive only	Active cooling

12.6 DON’T FORGET CHECKLIST

✅ Action

☐ ICU admission

☐ Check cortisol BEFORE levothyroxine

☐ Give hydrocortisone BEFORE/WITH levothyroxine

☐ PASSIVE rewarming only

☐ Search for precipitant

☐ Caution with IV fluids (dilutional hyponatremia)

☐ Avoid sedatives

☐ Lower LT4 dose if elderly/cardiac

☐ Monitor closely

📚 ABBREVIATIONS

Abbreviation	Full Form
ABG	Arterial Blood Gas
ACTH	Adrenocorticotropic Hormone
ADH	Antidiuretic Hormone
APS	Autoimmune Polyglandular Syndrome
CAD	Coronary Artery Disease
CK	Creatine Kinase
CNS	Central Nervous System
CVA	Cerebrovascular Accident
D5	5% Dextrose
D10	10% Dextrose
D5NS	5% Dextrose in Normal Saline
FT3	Free Triiodothyronine
FT4	Free Thyroxine
GCS	Glasgow Coma Scale
GI	Gastrointestinal
HF	Heart Failure
ICU	Intensive Care Unit
IV	Intravenous
LDH	Lactate Dehydrogenase
LT4	Levothyroxine
LV	Left Ventricle
MI	Myocardial Infarction
NG	Nasogastric
NS	Normal Saline
PO	Per Oral
SpO2	Oxygen Saturation
SVR	Systemic Vascular Resistance
T3	Triiodothyronine
T4	Thyroxine
TFT	Thyroid Function Test
TSH	Thyroid-Stimulating Hormone
UTI	Urinary Tract Infection

📖 KEY REFERENCES

Source

Jonklaas J et al. Guidelines for Hypothyroidism in Adults. Thyroid 2014

Klubo-Gwiezdzinska J, Wartofsky L. Thyroid Emergencies. Med Clin North Am 2012

Wall CR. Myxedema Coma: Diagnosis and Treatment. Am Fam Physician 2000

Wartofsky L. Myxedema Coma. Endocrinol Metab Clin North Am 2006

Mathew V et al. Myxedema Coma: A New Look into an Old Crisis. J Thyroid Res 2011

Ono Y et al. Clinical Characteristics and Outcomes of Myxedema Coma. J Endocr Soc 2017

Harrison’s Principles of Internal Medicine, 21st Edition

Williams Textbook of Endocrinology, 14th Edition

Document Version: 1.0

Last Updated: December 2025

For: Healthcare Professionals Only

Related Guidelines: Hypothyroidism; Adrenal Crisis

Key Points:

- Clinical diagnosis – Do NOT wait for labs
- Glucocorticoids BEFORE/WITH levothyroxine – Critical
- Passive rewarming ONLY – Active rewarming dangerous
- Search for and treat precipitant – Usually infection
- High mortality – Early aggressive treatment essential

End of Guideline

🛡️

Medical Advisory

Clinical guidelines are subject to change. Physicians should exercise their regular clinical judgment. This protocol does not replace individual institutional policies. Verified for Q1 2026.

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