Myxedema coma: Difference between revisions
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**Early respiratory support with intubation is necessary to prevent respiratory collapse | **Early respiratory support with intubation is necessary to prevent respiratory collapse | ||
*[[Hypercapnia]] | *[[Hypercapnia]] | ||
**There is often diaphragmatic dysfunction that causes worsening hypoventilation. The dysfunction is reversed after | **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> | ||
*[[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]] | ||
==Differential Diagnosis== | ==Differential Diagnosis== | ||
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*Abnormal Thyroid Hormone Levels | *Abnormal Thyroid Hormone Levels | ||
**In primary hypothyroidism then TSH will be elevated and T4 and T3 will be low | **In primary hypothyroidism then TSH will be elevated and T4 and T3 will be low | ||
**If the patient has secondary | **If the patient has secondary hypothyroidism (Pituitary dysfunction) the TSH can be low or normal and T4 and T3 will be low | ||
*[[Anemia]] | *[[Anemia]] | ||
*[[Rhabdomyolysis|Elevated CPK]] | *[[Rhabdomyolysis|Elevated CPK]] | ||
| Line 78: | Line 78: | ||
==Management== | ==Management== | ||
===Respiratory Support=== | ===Respiratory Support=== | ||
*Early mechanical ventilation will prevent | *Early mechanical ventilation will prevent respiratory collapse and severe respiratory acidosis. | ||
===Fluid Resuscitation=== | ===Fluid Resuscitation=== | ||
*Patients are often intravsascularly depleted and have an underlying infection mandating | *Patients are often intravsascularly depleted and have an underlying infection mandating aggressive fluid resuscitation | ||
*In patients who are hyponatremia, be cautious with rapid correction of hyponatremia and choose an appropriate fluid | *In patients who are hyponatremia, be cautious with rapid correction of hyponatremia and choose an appropriate fluid | ||
*Hypoglycemic patients will require intravenous dextrose added into the fluids | *Hypoglycemic patients will require intravenous dextrose added into the fluids | ||
===Hypotension=== | ===Hypotension=== | ||
*[[Vasopressors]] will be ineffective without concomitant thyroid hormone replacement | *[[Vasopressors]] will be ineffective without concomitant thyroid hormone replacement | ||
===Hormone | ===Hormone Replacement=== | ||
*'''Hydrocortisone''' 100mg q8hr IV since there is also adrenal insufficiency present | *'''Hydrocortisone''' 100mg q8hr IV since there is also adrenal insufficiency present | ||
**Alternative | **Alternative: Dexamethasone 2-4mg q12hrs (will not affect cortisol level or ACTH stimulation test) | ||
*'''Levothyroxine (T4)''' (generally agreed upon first line therapy) | *'''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 | ||
**Potentially safer in patients with CAD | **Potentially safer in patients with CAD | ||
*American Thyroid Association recommends | **American Thyroid Association recommends treatment with both T4 and T3<ref>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.</ref> | ||
*'''T3''' | *'''T3''' 20mcg IV followed by 2.5-10mcg q8hr | ||
**Start with 10mcg if elderly or has CAD | **Start with 10mcg if elderly or has CAD | ||
**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=== | ===Hypothermia=== | ||
*Treat with passive rewarming | *Treat with passive rewarming | ||
Revision as of 09:51, 21 February 2016
Background
- Hypothyroidism + mental status changes/coma + hypothermia + precipitating stressor[1]
- Majority of the patients will be > 60yo[2]
- Occurs in 0.1% of patients with hypothyroidism
- Mortality may be as high as 60%[3]
- Coma does not need to be present but there will be a decline in the patient's mental status. Sever hypothyroidism may present with severe decompensated hypothyroidism as the first presentation of undiagnosed hypothyroidism[4]
- The classic myxedematous face, which is characterized by generalized puffiness, macroglossia, ptosis, periorbital edema may not be present, but other signs such as a palpaple goiter and thyroid medication use will help in suspecting the diagnosis.
Precipitants
- Bradycardia and hypothermia
- Burns
- CHF
- CVA
- Cold exposure
- GI bleed
- Metabolic abnormalities (hypoxia, hypercapnia, hyponatremia, hypoglycemia)
- Medications: B-blockers, sedatives, narcotics, phenothiazine, amiodarone[5]
- Medication non-compliance (thyroid meds)
- MI
- Sepsis
- Trauma
Clinical Features
Hypothermia
- Temperature <35.5°C (95.9°F).
Cardiovascular
Pulmonary
- Hypoventilation
- Early respiratory support with intubation is necessary to prevent respiratory collapse
- Hypercapnia
- There is often diaphragmatic dysfunction that causes worsening hypoventilation. The dysfunction is reversed after thyroid hormone administration[6]
- Pleural Effusion
- Upper airway obstruction from glottic edema, vocal cord edema, and macroglossia can complicate intubation.
Neurologic
Differential Diagnosis
Diagnosis
Work-Up
- Chemistry
- CBC
- TSH, FT4, FT3
- Cultures
- LFT
- Cortisol level
- VBG
- CXR
- EKG
Lab Abnormalities
- Abnormal Thyroid Hormone Levels
- In primary hypothyroidism then TSH will be elevated and T4 and T3 will be low
- If the patient has secondary hypothyroidism (Pituitary dysfunction) the TSH can be low or normal and T4 and T3 will be low
- Anemia
- Elevated CPK
- Elevated creatinine
- Elevated transaminases
- Hypercapnia
- Hyperlipidemia
- Hypoglycemia
- Hyponatremia
- Hypoxia
- Leukopenia
- Respiratory acidosis
Management
Respiratory Support
- Early mechanical ventilation will prevent respiratory collapse and severe respiratory acidosis.
Fluid Resuscitation
- Patients are often intravsascularly depleted and have an underlying infection mandating aggressive fluid resuscitation
- In patients who are hyponatremia, be cautious with rapid correction of hyponatremia and choose an appropriate fluid
- Hypoglycemic patients will require intravenous dextrose added into the fluids
Hypotension
- Vasopressors will be ineffective without concomitant thyroid hormone replacement
Hormone Replacement
- Hydrocortisone 100mg q8hr IV since there is also adrenal insufficiency present
- Alternative: Dexamethasone 2-4mg q12hrs (will not affect cortisol level or ACTH stimulation test)
- 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.[7]
- 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[8]
- 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
Hypothermia
- Treat with passive rewarming
- Hypothermia will also reverse with thryoid hormone administration
Disposition
- Admit to ICU
See Also
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.
- ↑ 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.
- ↑ 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.
- ↑ Martinez FJ et al. Hypothyroidism. A reversible cause of diaphragmatic dysfunction. Chest. 1989;96:1059–63.
- ↑ 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.