Myxedema coma
Background
- Myxedema: thick, nonpitting edematous changes to skin and soft tissues
- occurs in 0.1% of patients with hypothyroid
- 80% mortality
Precipitants
- Exposure to Cold
- Infection (esp pulmonary)
- CHF
- Trauma
- Drugs: phenothiazines, pheobarbitol, narcotics, anesthetics, bdzs, lithium
- Iodides
- CVA
- Hemorrhage (GI)
Diagnosis
- AMS
- unsteady gait
- Skin findings (cool, dry, coarse, pale)
- soft tissues with nonpitting, waxy, dry edema (periorbital edema)
- loss of axillary and pubic hair
- Hypothermia (core temp <37C)
- Cardiovascular alterations (bradycardia)
- Hypoventilation --> respiratory collapse
- abdominal distension
- Delayed DTRs
- Precipitant
- Hypoglycemia
- Hyponatremia
Work-Up
- Chem panel (shows hyponatremia)
- serum osms
- accucheck (may be normal or low)
- CBC
- cultures
- total CK
- LFTS
- LDH
- TSH, FT4, FT3
- cortisol level
- ABG
- ECHO
- CXR
- EKG
DDx
- CHF
- Pulmonary Edema
- hypoventilation syndromes
- hypothermia
- Depression/SI
- hepatic encephalopathy
- shock
- CVA
Treatment
- Intubation and mechanical ventilation if pt has significant respiratory acidosis, hypercapnia, or hypoxia
- IV thyroid replacement
- 500-800 mcg of Levothyroxine then 50-100mcg IV qday
- consider 10-20mcg q12hrs IV of T3 in younger patients with low cardiovascular risk
- Steroid Replacement
- 5-10mg/hr IV hydrocortisone
- treat associated infections
- correct severe hyponatremia and hypoglycemia
passive external rewarming
Disposition
- Admit to ICU
- get endocrine consult
See Also
Thyroid (General)
Source
Emedicine
Adapted from PANI, Clarke