Myxedema coma: Difference between revisions
No edit summary
Line 1: Line 1:
==Background==
==Background==
* Myxedema: thick, nonpitting edematous changes to skin and soft tissues
#Hypothyroidism + mental status changes/coma + hypothermia + precipitating stressor
* occurs in 0.1% of patients with hypothyroid
##80% mortality
* 80% mortality
#Occurs in 0.1% of patients with hypothyroidism


==Precipitants==
==Precipitants==
#Exposure to Cold
#Infection
#Infection (esp pulmonary)
##Bradycardia and hypothermia may mask usual signs of fever
#Cold exposure
#Trauma
#MI
#CHF
#CHF
#Trauma
#Drugs: phenothiazines, pheobarbitol, narcotics, anesthetics, bdzs, lithium
#Iodides
#CVA
#CVA
#Hemorrhage (GI)
#GI bleed
#Metabolic conditions (hypoxia, hypercapnia, hyponatremia, hypoglycemia)
#Burns
#Meds: B-blockers, sedatives, narcotics, phenothiazine, amiodarone
#Medication non-compliance (thyroid meds)


==Diagnosis==
==Diagnosis==
#AMS
#Hypothermia
#unsteady gait
##So common in myxedema that a normal temperature should suggest an underlying infection
#Skin findings (cool, dry, coarse, pale)
##Absence of shivering distinguishes from accidental hypothermia
#soft tissues with nonpitting, waxy, dry edema (periorbital edema)
#Cardio
#loss of axillary and pubic hair
##Bradycardia
#Hypothermia (core temp <37C)
##Hypotension
#Cardiovascular alterations (bradycardia)
#Pulm
#Hypoventilation --> respiratory collapse
##Hypoventilation -> respiratory collapse  
#abdominal distension
###CO2 narcosis
#Delayed DTRs
##Pleural effusions
#Precipitant
##Upper airway obstruction from glottic edema, vocal cord edema, and macroglossia
#Hypoglycemia
#Neuro
#Hyponatremia
##AMS/coma


==Work-Up==
==Work-Up==
#Chem panel (shows hyponatremia)
#Chemistry
#serum osms
#accucheck (may be normal or low)
#CBC
#CBC
#cultures
#total CK
#LFTS
#LDH
#TSH, FT4, FT3
#TSH, FT4, FT3
#cortisol level
#Cultures
#ABG
#LFT
#ECHO
#Cortisol level
#VBG
#CXR  
#CXR  
#EKG  
#EKG  
   
   
==DDx==
==DDx==
#Sepsis
#Depression
#Adrenal crisis
#CHF
#CHF
#Pulmonary Edema
#Hypoglycemia
#hypoventilation syndromes
#CVA
#hypothermia
#Hypothermia
#Depression/SI
#Drug overdose
#hepatic encephalopathy
#Meningitis
#shock
#CVA


==Treatment==
==Treatment==
#Intubation and mechanical ventilation if pt has significant respiratory acidosis, hypercapnia, or hypoxia
#Supportive care
#IV thyroid replacement
##Respiratory distress
##500-800 mcg  of Levothyroxine then 50-100mcg IV qday
###Mechanical ventilation if needed
##consider 10-20mcg q12hrs IV of T3 in younger patients with low cardiovascular risk
##Hypoglycemia
#Steroid Replacement
###IV dextrose
##5-10mg/hr IV hydrocortisone
##Hyponatremia
#treat associated infections
###Water restriction
#correct severe hyponatremia and hypoglycemia
##Hypotension
passive external rewarming 
###Vasopressors (ineffective w/o thyroid hormone replacement)
###Hydrocortisone 100mg q8hr IV (adrenal insufficiency may also be present)
####Give first dose before starting thyroid replacement therapy
##Hypothermia
###Treat w/ passive rewarming (active rewarming may cause hypotension)
#Thyroid replacement therapy
##Optimal regimen is controversial
##Can give T3 or T4 or both
##T4
###Advantages
####Smooth, slow steady onset of action
####May be safer in pts with CAD
###Disadvantages
####Requires extrathyroidal conversion of T4 -> T3 to work (may be reduced in myxedema)
###Dose: Start 4mcg/kg IV followed by 100mcg IV in 24hr
##T3
###Advantages
####Does not require extrathyroidal action to work
####Rapid onset of action
###Disadvantages
####Rapid onset of action (may not be desirable in pts w/ CAD)
###Dose: 20mcg IV followed by 10mcg q8hr until pt is conscious
####Start with 10mcg if elderly or has CAD
#Treaty precipitating factors


==Disposition==
==Disposition==
#Admit to ICU
#Admit to ICU
#get endocrine consult  
#Endocrine consult  


==See Also==
==See Also==
[[Hypothyroidism]]
[[Hypothyroidism]]
 
[[Thyroid (General)]]
Thyroid (General)


==Source==
==Source==
Emedicine
Tintinalli's
 
Adapted from PANI, Clarke


[[Category:Endo]]
[[Category:Endo]]

Revision as of 01:12, 28 September 2011

Background

  1. Hypothyroidism + mental status changes/coma + hypothermia + precipitating stressor
    1. 80% mortality
  2. Occurs in 0.1% of patients with hypothyroidism

Precipitants

  1. Infection
    1. Bradycardia and hypothermia may mask usual signs of fever
  2. Cold exposure
  3. Trauma
  4. MI
  5. CHF
  6. CVA
  7. GI bleed
  8. Metabolic conditions (hypoxia, hypercapnia, hyponatremia, hypoglycemia)
  9. Burns
  10. Meds: B-blockers, sedatives, narcotics, phenothiazine, amiodarone
  11. Medication non-compliance (thyroid meds)

Diagnosis

  1. Hypothermia
    1. So common in myxedema that a normal temperature should suggest an underlying infection
    2. Absence of shivering distinguishes from accidental hypothermia
  2. Cardio
    1. Bradycardia
    2. Hypotension
  3. Pulm
    1. Hypoventilation -> respiratory collapse
      1. CO2 narcosis
    2. Pleural effusions
    3. Upper airway obstruction from glottic edema, vocal cord edema, and macroglossia
  4. Neuro
    1. AMS/coma

Work-Up

  1. Chemistry
  2. CBC
  3. TSH, FT4, FT3
  4. Cultures
  5. LFT
  6. Cortisol level
  7. VBG
  8. CXR
  9. EKG

DDx

  1. Sepsis
  2. Depression
  3. Adrenal crisis
  4. CHF
  5. Hypoglycemia
  6. CVA
  7. Hypothermia
  8. Drug overdose
  9. Meningitis

Treatment

  1. Supportive care
    1. Respiratory distress
      1. Mechanical ventilation if needed
    2. Hypoglycemia
      1. IV dextrose
    3. Hyponatremia
      1. Water restriction
    4. Hypotension
      1. Vasopressors (ineffective w/o thyroid hormone replacement)
      2. Hydrocortisone 100mg q8hr IV (adrenal insufficiency may also be present)
        1. Give first dose before starting thyroid replacement therapy
    5. Hypothermia
      1. Treat w/ passive rewarming (active rewarming may cause hypotension)
  2. Thyroid replacement therapy
    1. Optimal regimen is controversial
    2. Can give T3 or T4 or both
    3. T4
      1. Advantages
        1. Smooth, slow steady onset of action
        2. May be safer in pts with CAD
      2. Disadvantages
        1. Requires extrathyroidal conversion of T4 -> T3 to work (may be reduced in myxedema)
      3. Dose: Start 4mcg/kg IV followed by 100mcg IV in 24hr
    4. T3
      1. Advantages
        1. Does not require extrathyroidal action to work
        2. Rapid onset of action
      2. Disadvantages
        1. Rapid onset of action (may not be desirable in pts w/ CAD)
      3. Dose: 20mcg IV followed by 10mcg q8hr until pt is conscious
        1. Start with 10mcg if elderly or has CAD
  3. Treaty precipitating factors

Disposition

  1. Admit to ICU
  2. Endocrine consult

See Also

Hypothyroidism Thyroid (General)

Source

Tintinalli's

Retrieved from "https://www.wikem.org/w/index.php?title=Myxedema_coma&oldid=5922"