Myxedema coma: Difference between revisions
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==Background== | ==Background== | ||
*Hypothyroidism + mental status changes/coma + hypothermia + precipitating stressor<ref>Wall CR. Myxedema coma: diagnosis and treatment. Am Fam Physician. Dec 1 2000;62(11):2485-90.</ref> | *[[Hypothyroidism]] + [[AMS|mental status changes]]/[[coma]] + [[hypothermia]] + precipitating stressor<ref>Wall CR. Myxedema coma: diagnosis and treatment. Am Fam Physician. Dec 1 2000;62(11):2485-90.</ref> | ||
*Majority of the patients | *Majority of the patients > 60yo<ref>Davis PJ, Davis FB. Hypothyroidism in the elderly. Compr Ther. 1984;10:17–23.</ref> | ||
*Occurs in 0.1% of patients with hypothyroidism | *Occurs in 0.1% of patients with hypothyroidism | ||
**Usually occurs after precipitating incident in patient with untreated hypothyroidism <ref>Thiessen, M. (2018). Thyroid and Adrenal Disorders. Rosen's Emergency Medicine (9th ed.). Philadelphia, PA: Elsevier/Saunders.</ref> | |||
*Mortality may be as high as 60%<ref>Arlot S et al. Myxoedema coma: response of thyroid hormones with oral and intravenous high-dose L-thyroxine treatment. Intensive Care Med. 1991;17:16–8.</ref> | *Mortality may be as high as 60%<ref>Arlot S et al. Myxoedema coma: response of thyroid hormones with oral and intravenous high-dose L-thyroxine treatment. Intensive Care Med. 1991;17:16–8.</ref> | ||
* | *Untreated mortality approaches 100% <ref>Thiessen, M. (2018). Thyroid and Adrenal Disorders. Rosen's Emergency Medicine (9th ed.). Philadelphia, PA: Elsevier/Saunders.</ref> | ||
*~50% of cases become evident '''''after''''' admission | |||
*Severe hypothyroidism may be first time presentation of hypothyroid<ref>Nicoloff JT et al. A form of decompensated hypothyroidism. Endocrinol Metab Clin North Am. 1993;22:279–90.</ref> | |||
===Precipitants=== | ===Precipitants=== | ||
*Bradycardia and hypothermia | *[[Bradycardia]] and [[hypothermia]] | ||
*Burns | *[[Burns]] | ||
*[[CHF]] | *[[CHF]] | ||
*[[CVA]] | *[[CVA]] | ||
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*[[GI bleed]] | *[[GI bleed]] | ||
*Metabolic abnormalities ([[hypoxia]], [[hypercapnia]], [[hyponatremia]], [[hypoglycemia]]) | *Metabolic abnormalities ([[hypoxia]], [[hypercapnia]], [[hyponatremia]], [[hypoglycemia]]) | ||
*Medications: | *Medications: [[Beta blockers]], [[sedatives]], [[opioids]], [[phenothiazines]], [[amiodarone]]<ref>Mazonson PD et al. Myxedema coma during long-term amiodarone therapy. Am J Med. 1984;77:751–4.</ref> | ||
*Medication non- | **Especially medications with CNS depressant effect <ref>Thiessen, M. (2018). Thyroid and Adrenal Disorders. Rosen's Emergency Medicine (9th ed.). Philadelphia, PA: Elsevier/Saunders.</ref> | ||
*Medication non-adherence (thyroid meds) | |||
*[[MI]] | *[[MI]] | ||
*[[Sepsis]] | *[[Sepsis]] | ||
*Trauma | *[[Trauma]] | ||
*[[PE]] | |||
{{Thyroid gen background}} | |||
==Clinical Features== | ==Clinical Features== | ||
===Hypothermia=== | [[File:Myxedema face.png|thumb|Man with myxedema or severe hypothyroidism showing an expressionless face, puffiness around the eyes and pallor.]] | ||
[[File:Myxedema standing.png|thumb|Additional symptoms include swelling of the arms and legs and ascites.]] | |||
[[File:PMC3371544 IJD-57-247-g001.png|thumb|Pretibial "woody" (i.e. non-pitting) myxedema]] | |||
[[File:PMC2923795 jkms-25-1394-g001.png|thumb|A case of myxedema coma presenting as a brain stem infarct in a 74-year-old Korean woman. (A, B) Severe periorbital edema and thinned eyebrow. (C, D) Non-pitting edema and desquamation of the hands and feet.]] | |||
===[[Hypothermia]]=== | |||
*Temperature <35.5°C (95.9°F). | *Temperature <35.5°C (95.9°F). | ||
===Cardiovascular=== | ===Cardiovascular=== | ||
*[[Bradycardia]] | *[[Bradycardia]] | ||
*[[Hypotension]] | *[[Hypotension]] | ||
*[[Pericardial effusion]] | |||
===Pulmonary=== | ===Pulmonary=== | ||
*Hypoventilation | *Hypoventilation, [[hypercapnia]] | ||
**There is often diaphragmatic dysfunction that causes worsening hypoventilation. The dysfunction is reversed after thyroid hormone administration<ref>Martinez FJ et al. Hypothyroidism. A reversible cause of diaphragmatic dysfunction. Chest. 1989;96:1059–63.</ref> | **There is often diaphragmatic dysfunction that causes worsening hypoventilation. The dysfunction is reversed after thyroid hormone administration<ref>Martinez FJ et al. Hypothyroidism. A reversible cause of diaphragmatic dysfunction. Chest. 1989;96:1059–63.</ref> | ||
**Early respiratory support with intubation may be necessary to prevent respiratory collapse | |||
*[[Hypoxia]] | |||
*[[Pleural Effusion]] | *[[Pleural Effusion]] | ||
*Upper airway obstruction from glottic edema, vocal cord edema, and macroglossia can complicate intubation. | *Upper airway obstruction from glottic edema, vocal cord edema, and macroglossia can complicate intubation. | ||
===Neurologic=== | ===Neurologic=== | ||
*[[Altered mental status]]/[[Coma]] | *[[Altered mental status]]/[[Coma]] due to CO2 narcosis | ||
*[[Coma]] is very rare | |||
*Pseudomyotonic "hung up" deep tendon reflexes | |||
**Particularly Achilles reflex | |||
**Relaxation phase of DTR twice as long as contraction phase | |||
*Neuropsychiatric symptoms <ref>Thiessen, M. (2018). Thyroid and Adrenal Disorders. Rosen's Emergency Medicine (9th ed.). Philadelphia, PA: Elsevier/Saunders.</ref> | |||
**[[Depression]] | |||
**[[Psychosis]] | |||
==Differential Diagnosis== | ==Differential Diagnosis== | ||
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*[[Sepsis]] | *[[Sepsis]] | ||
== | ==Evaluation== | ||
[[File:PMC2923795 jkms-25-1394-g002.png|thumb|ECG showing sinus bradycardia, low QRS voltage, and a prolonged QT interval.]] | |||
===Work-Up=== | ===Work-Up=== | ||
*TSH, FT4, FT3 | |||
**In primary hypothyroidism TSH will be elevated and T4 and T3 will be low | |||
**If the patient has secondary hypothyroidism (Pituitary dysfunction) the TSH may be low or normal and T4 and T3 will be low | |||
*Chemistry | *Chemistry | ||
**[[Hyponatremia]] | |||
**[[Hypoglycemia]] | |||
**+/- [[renal failure|Elevated creatinine]] | |||
*CBC | *CBC | ||
* | **Mild [[anemia]], [[leukopenia]] | ||
* | *[[Blood cultures]] | ||
* | *[[LFTs]] | ||
**Elevated transaminases | |||
*[[Rhabdomyolysis|Elevated CPK]] | |||
*Cortisol level | *Cortisol level | ||
*VBG | *[[VBG]]/ABG | ||
*CXR | **[[Hypercapnia]] | ||
* | **Hypoxia | ||
*Lipid levels | |||
**Hypercholesterolemia | |||
*[[CXR]] | |||
*[[ECG]] | |||
**Sinus bradycardia | |||
**Non-specific ST-T wave changes | |||
**Prolonged QTc | |||
**Ventricular dysrhythmias | |||
*Bedside [[cardiac US]] for [[pericardial effusion]] | |||
=== | ===Diagnosis=== | ||
[[File:thyroid studies.JPG|px200]] | |||
==Management== | ==Management== | ||
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*Early mechanical ventilation will prevent respiratory collapse and severe respiratory acidosis. | *Early mechanical ventilation will prevent respiratory collapse and severe respiratory acidosis. | ||
===Fluid Resuscitation=== | ===Fluid Resuscitation=== | ||
* | *Often intravascularly depleted | ||
*In patients who are | **May have underlying illness causing dehydration | ||
* | *In patients who are hyponatremic, be cautious with rapid correction of hyponatremia | ||
===Hypotension=== | **Consider fluid restriction | ||
*Use D5NS if hypoglycemic | |||
*Monitor for unmasking of CHF | |||
===[[Hypotension]]=== | |||
*[[Vasopressors]] will be ineffective without concomitant thyroid hormone replacement | *[[Vasopressors]] will be ineffective without concomitant thyroid hormone replacement | ||
===Hormone Replacement=== | ===Hormone Replacement=== | ||
*''' | *'''[[Levothyroxine]] (T4)''' (generally agreed upon first line therapy) | ||
**Dose: 100 to 500 mcg (4mcg/kg IV) followed by 75 to 100 mcg administered IV daily until the patient takes oral replacement.<ref>Smallridge RC. Metabolic and anatomic thyroid emergencies: a review. Crit Care Med. 1992;20:276–91</ref> | **Dose: 100 to 500 mcg (4mcg/kg IV) followed by 75 to 100 mcg administered IV daily until the patient takes oral replacement.<ref>Smallridge RC. Metabolic and anatomic thyroid emergencies: a review. Crit Care Med. 1992;20:276–91</ref> | ||
**Does require extrathyroidal conversion which can be reduced in myxedema but will have a slow steady onset of action | **Does require extrathyroidal conversion which can be reduced in myxedema but will have a slow steady onset of action | ||
Line 97: | Line 124: | ||
**Does not require extrathyroidal conversion | **Does not require extrathyroidal conversion | ||
**More rapid onset but may be harmful in patients with CAD | **More rapid onset but may be harmful in patients with CAD | ||
===Hypothermia=== | |||
*Treat with passive rewarming | ===[[Adrenal Insufficiency]]=== | ||
*Hypothermia will also reverse with | *[[Hydrocortisone]] 100 mg IV q8h for possible concomitant adrenal insufficiency | ||
**Alternative: [[dexamethasone]] 2-4mg q12hrs (will not affect cortisol level or ACTH stimulation test) | |||
===[[Hypothermia]]=== | |||
*Treat with passive rewarming | |||
*[[Hypothermia]] will also reverse with thyroid hormone administration | |||
*Avoid mechanical stimulation | |||
*Do not actively rewarm: | |||
**Usually are volume depleted | |||
**Rapid peripheral vasodilation may induce worsening hypotension | |||
==Disposition== | ==Disposition== | ||
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*[[Hypothyroidism]] | *[[Hypothyroidism]] | ||
*[[Thyroid (Main)]] | *[[Thyroid (Main)]] | ||
==External Links== | |||
*[https://emcrit.org/ibcc/myxedema/ IBCC Decompensated Hypothyroidism (“Myxedema Coma”)] | |||
==References== | ==References== |
Revision as of 18:40, 2 January 2020
Background
- Hypothyroidism + mental status changes/coma + hypothermia + precipitating stressor[1]
- Majority of the patients > 60yo[2]
- Occurs in 0.1% of patients with hypothyroidism
- Usually occurs after precipitating incident in patient with untreated hypothyroidism [3]
- Mortality may be as high as 60%[4]
- Untreated mortality approaches 100% [5]
- ~50% of cases become evident after admission
- Severe hypothyroidism may be first time presentation of hypothyroid[6]
Precipitants
- Bradycardia and hypothermia
- Burns
- CHF
- CVA
- Cold exposure
- GI bleed
- Metabolic abnormalities (hypoxia, hypercapnia, hyponatremia, hypoglycemia)
- Medications: Beta blockers, sedatives, opioids, phenothiazines, amiodarone[7]
- Especially medications with CNS depressant effect [8]
- Medication non-adherence (thyroid meds)
- MI
- Sepsis
- Trauma
- PE
Spectrum of Thyroid Disease
- Myxedema coma << hypothyroidism < euthyroid > hyperthyroidism >> thyroid storm
Clinical Features
Hypothermia
- Temperature <35.5°C (95.9°F).
Cardiovascular
Pulmonary
- Hypoventilation, hypercapnia
- There is often diaphragmatic dysfunction that causes worsening hypoventilation. The dysfunction is reversed after thyroid hormone administration[9]
- Early respiratory support with intubation may be necessary to prevent respiratory collapse
- Hypoxia
- Pleural Effusion
- Upper airway obstruction from glottic edema, vocal cord edema, and macroglossia can complicate intubation.
Neurologic
- Altered mental status/Coma due to CO2 narcosis
- Coma is very rare
- Pseudomyotonic "hung up" deep tendon reflexes
- Particularly Achilles reflex
- Relaxation phase of DTR twice as long as contraction phase
- Neuropsychiatric symptoms [10]
Differential Diagnosis
Evaluation
Work-Up
- TSH, FT4, FT3
- In primary hypothyroidism TSH will be elevated and T4 and T3 will be low
- If the patient has secondary hypothyroidism (Pituitary dysfunction) the TSH may be low or normal and T4 and T3 will be low
- Chemistry
- CBC
- Mild anemia, leukopenia
- Blood cultures
- LFTs
- Elevated transaminases
- Elevated CPK
- Cortisol level
- VBG/ABG
- Hypercapnia
- Hypoxia
- Lipid levels
- Hypercholesterolemia
- CXR
- ECG
- Sinus bradycardia
- Non-specific ST-T wave changes
- Prolonged QTc
- Ventricular dysrhythmias
- Bedside cardiac US for pericardial effusion
Diagnosis
Management
Respiratory Support
- Early mechanical ventilation will prevent respiratory collapse and severe respiratory acidosis.
Fluid Resuscitation
- Often intravascularly depleted
- May have underlying illness causing dehydration
- In patients who are hyponatremic, be cautious with rapid correction of hyponatremia
- Consider fluid restriction
- Use D5NS if hypoglycemic
- Monitor for unmasking of CHF
Hypotension
- Vasopressors will be ineffective without concomitant thyroid hormone replacement
Hormone Replacement
- Levothyroxine (T4) (generally agreed upon first line therapy)
- Dose: 100 to 500 mcg (4mcg/kg IV) followed by 75 to 100 mcg administered IV daily until the patient takes oral replacement.[11]
- Does require extrathyroidal conversion which can be reduced in myxedema but will have a slow steady onset of action
- Potentially safer in patients with CAD
- American Thyroid Association recommends treatment with both T4 and T3[12]
- T3 20mcg IV followed by 2.5-10mcg q8hr
- Start with 10mcg if elderly or has CAD
- Does not require extrathyroidal conversion
- More rapid onset but may be harmful in patients with CAD
Adrenal Insufficiency
- Hydrocortisone 100 mg IV q8h for possible concomitant adrenal insufficiency
- Alternative: dexamethasone 2-4mg q12hrs (will not affect cortisol level or ACTH stimulation test)
Hypothermia
- Treat with passive rewarming
- Hypothermia will also reverse with thyroid hormone administration
- Avoid mechanical stimulation
- Do not actively rewarm:
- Usually are volume depleted
- Rapid peripheral vasodilation may induce worsening hypotension
Disposition
- Admit to ICU
See Also
External Links
References
- ↑ Wall CR. Myxedema coma: diagnosis and treatment. Am Fam Physician. Dec 1 2000;62(11):2485-90.
- ↑ Davis PJ, Davis FB. Hypothyroidism in the elderly. Compr Ther. 1984;10:17–23.
- ↑ Thiessen, M. (2018). Thyroid and Adrenal Disorders. Rosen's Emergency Medicine (9th ed.). Philadelphia, PA: Elsevier/Saunders.
- ↑ Arlot S et al. Myxoedema coma: response of thyroid hormones with oral and intravenous high-dose L-thyroxine treatment. Intensive Care Med. 1991;17:16–8.
- ↑ Thiessen, M. (2018). Thyroid and Adrenal Disorders. Rosen's Emergency Medicine (9th ed.). Philadelphia, PA: Elsevier/Saunders.
- ↑ Nicoloff JT et al. A form of decompensated hypothyroidism. Endocrinol Metab Clin North Am. 1993;22:279–90.
- ↑ Mazonson PD et al. Myxedema coma during long-term amiodarone therapy. Am J Med. 1984;77:751–4.
- ↑ Thiessen, M. (2018). Thyroid and Adrenal Disorders. Rosen's Emergency Medicine (9th ed.). Philadelphia, PA: Elsevier/Saunders.
- ↑ Martinez FJ et al. Hypothyroidism. A reversible cause of diaphragmatic dysfunction. Chest. 1989;96:1059–63.
- ↑ Thiessen, M. (2018). Thyroid and Adrenal Disorders. Rosen's Emergency Medicine (9th ed.). Philadelphia, PA: Elsevier/Saunders.
- ↑ Smallridge RC. Metabolic and anatomic thyroid emergencies: a review. Crit Care Med. 1992;20:276–91
- ↑ Jonklaas J, Bianco AC, Bauer AJ, Burman KD, Cappola AR, Celi FS, et al. Guidelines for the treatment of hypothyroidism: prepared by the american thyroid association task force on thyroid hormone replacement. Thyroid. 2014 Dec. 24 (12):1670-751.