Myxedema coma

Myxedema coma - Acute
Rahul Soman, M. Pharm

 

Definition  

A state of profound decompensated hypothyroidism that is a life-threatening endocrine emergency .

 

Medical History  

* Hypothyroidism

* Hypothermia [Hypothermia - Acute]

* Exposure to cold weather

* Infectious disease

* Surgical procedure

* Burn

* Traumatic injury

* Gastrointestinal hemorrhage

* Congestive heart failure

* Cerebrovascular accident

* Lithium Carbonate use

* Analgesic use

* Sedative use

* Amiodarone use

* Beta-Adrenergic Blocker use

* Phenytoin use

* Rifampin use

* Alcohol consumption

 

Findings  

* Altered mental status

* Hypothermia - Acute

* Lethargy

* Memory impairment

* Bradyarrhythmia - Acute

* Hypotension

* Somnolence

* Stupor

* Slow respiration

* Hypoxia

* Cool skin

* Dry skin

* Brittle hair

* Edema of lower extremity

* Constipation

* Abdominal distension

* Pharyngeal swelling

* Seizure

* Hallucinations

* Abnormal deep tendon reflex

* Heart sounds diminished

* Hypothyroid facies

* Goiter

* Thyroid eye disease

 

Tests  

Suspected or known hypothyroidism  

* Thyroid stimulating hormone measurement: Overt hypothyroidism is classified as a TSH above the upper limit of the reference range in the presence of a low serum free thyroxine (FT4) . Subclinical hypothyroidism is a laboratory diagnosis defined as a TSH above the upper limit of the reference range in the presence of a normal FT4.

 

Suspected or known hypothyroidism  

* Serum free T4 measurement: Free thyroxine (FT4) is decreased in conjunction with an elevated TSH level in primary hypothyroidism and in conjunction with a low, normal, or slightly elevated TSH level in secondary hypothyroidism .

 

Diagnostic evaluation of myxedema coma  

* Complete blood count

* Metabolic function test

* Arterial blood gas analysis

* Plain chest X-ray

* Electrocardiographic monitoring

 

Differential Diagnosis  

* Acquired hypothyroidism

* Sepsis - Acute

* Heart failure

* Severe depression

* Sick-euthyroid syndrome

 

Treatment  

 

Drug Therapy  

 

Myxedema coma  

 

LEVOTHYROXINE SODIUM  

Adults: Initial dose 200 mcg to 500 mcg IV daily; reduce dose to 50 mcg to 100 mcg IV daily until patient is able to take medication orally

 

LIOTHYRONINE SODIUM  

Adults: Initial dose 10 mcg to 20 mcg IV every 4 hours; reduce dosage to 10 mcg every 6 hours after 24 hours and continue this regimen for an additional 24 to 48 hours until patient is able to take medication orally

 

LEVOTHYROXINE SODIUM / LIOTHYRONINE SODIUM  

Adults: Initial loading dose 200 mcg to 300 mcg levothyroxine IV AND 10 mcg liothyronine IV; follow with maintenance dose 50 mcg to 100 mcg levothyroxine IV AND 10 mcg liothyronine IV every 8 hours until the patient is able to take oral medication

 

Suspected adrenal insufficiency  

 

HYDROCORTISONE  

Adults: Initial dose 100 mg IV (or equivalent) every 6 to 8 hours

 

Procedural Therapy  

 

Respiratory distress  

* Airway management: Airway management must assume the first priority in the management of any seriously ill or injured patient .