Myxedema (aka decompensated hypothyroidism): An EM Primer

Author: Alex Koyfman, MD (@EMHighAK, EM Attending Physician, UTSW / Parkland Memorial Hospital)

Editor: Brit Long, MD (@long_brit, EM Chief Resident at SAUSHEC, USAF)

Classic presentation: Elderly female with under-treated / undiagnosed hypothyroidism presents to ED during winter month; volume depleted + vasoconstricted, altered mental status

Why do we care? High mortality (30-60%)

 

How do patients present (clinical diagnosis)

AMS                                                      Hypothermia                         Hypotension

Respiratory Failure                      Hypoglycemia                      Hyponatremia

 

Potential physical exam findings

Hypothermia                             Sluggish/flat affect                 Hair loss

Puffy eyes                                    Thin eyebrows                          Big tongue

Distant heart sounds             Bradycardia                               Hoarse voice

Hypotension                                Slow RR                                       Obesity

Decreased bowel sounds      Nonpitting edema                Dry/rough skin

Decreased reflexes

 

Don’t just make the diagnosis, but identify the etiology

Infection                               MI                                                            Hypoglycemia

Cold environment          Hypoxia / hypercapnia                 Hyponatremia

Trauma                                   Drug(s)                                                 CHF

GI bleed                                Stroke                                                     Recent surgery

Burns                                      Medication non-compliance      PE

DKA                                         Hypercalcemia

 

Other diagnoses to consider

Sepsis                                      Hypoglycemia                       Hyponatremia

Meningitis                            Hypercarbia                            Environmental hypothermia

Drug OD                                  CHF                                           Stroke

Adrenal crisis

 

Management

-ABC

-Passive rewarming

-Dextrose for hypoglycemia

-Hydrocortisone 100mg IV for potential adrenal insufficiency; give prior to thyroid hormone

-Levothyroxine (T4) 100-500 micrograms IV initially (most receive on higher end)

-+/- L-triiodothyronine (T3) 10-20mcg IV; avoid in elderly / CAD as may cause MI or arrhythmia

-Treat concurrent conditions (i.e. infection/ischemia)

-MICU admit

 

Other valuable tidbits

-Don’t hesitate to initiate sepsis care

-If thyroid labs don’t come back in timely fashion, proceed with thyroid replacement

-CK is often elevated

-Potentially challenging intubation: oropharyngeal edema, macroglossia

-Use US to evaluate for pericardial effusion

-Vasopressors may be ineffective, especially without thyroid hormone replacement

 

References / Further Reading

– Rosen’s Emergency Medicine, 8th edition

– Harwood-Nuss’ Clinical Practice of Emergency Medicine, 6th edition

http://www.ncbi.nlm.nih.gov/pubmed/24360319

http://www.ncbi.nlm.nih.gov/pubmed/24766938

http://www.ncbi.nlm.nih.gov/pubmed/24766934

http://www.ncbi.nlm.nih.gov/pubmed/24481020

http://www.ncbi.nlm.nih.gov/pubmed/20537835

http://www.ncbi.nlm.nih.gov/pubmed/19857436

http://www.ncbi.nlm.nih.gov/pubmed/19371530

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