Management of Hypothyroidism with Hypothermia

Immediate Temperature Management

The American College of Critical Care Medicine recommends removing wet clothing immediately and insulating the patient from further environmental exposure to prevent additional heat loss 2, 3, 4
The American Heart Association suggests initiating active external warming using forced air warming devices or warming blankets, as passive rewarming alone is inadequate at this temperature 5
The American College of Critical Care Medicine advises administering warmed intravenous fluids and providing warm humidified oxygen as adjunctive measures 5
Increasing ambient room temperature to support rewarming efforts is recommended by the American College of Critical Care Medicine 2, 3, 4
The American College of Critical Care Medicine recommends monitoring core temperature continuously every 5 minutes using esophageal, bladder, or rectal thermometry with a low-reading thermometer capable of measuring below 35°C 1

The American College of Endocrinology states that myxedema coma is a life-threatening endocrine emergency that commonly presents with severe hypothermia and requires immediate recognition, and cardiovascular instability, such as bradycardia, hypotension, or risk of cardiac arrest, is a key clinical feature 1
Obtaining cortisol level immediately to evaluate for adrenal insufficiency in all hypothermic patients is essential, as recommended by the American College of Endocrinology 1
The American College of Endocrinology advises obtaining arterial blood gas to assess metabolic acidosis and ventilation status 1
Coagulation studies, including PT/PTT, should be performed, as hypothermia impairs platelet function and clotting factors, with PTT increasing from 36 seconds at 37°C to 57 seconds at 28°C, according to the American College of Critical Care Medicine 1
A 12-lead ECG should be performed to identify bradycardia, prolonged PR interval, and potential Osborne (J) waves, as recommended by the American College of Cardiology 1

Handling the patient gently during examination and procedures to avoid precipitating ventricular fibrillation in hypothermia is crucial, as recommended by the American College of Critical Care Medicine 1
Continuous cardiac monitoring is mandatory for arrhythmia detection, according to the American College of Cardiology 1

If cardiac arrest occurs, initiating full resuscitative measures, including CPR, and defibrillation attempts may be reasonable according to standard BLS algorithm concurrent with rewarming, as recommended by the American Heart Association 6
The American Heart Association advises not to pronounce death until the patient has been rewarmed, as severe hypothermia can mimic brain death 6, 1

Watching for rewarming complications, including rewarming shock, arrhythmias, and hypotension, is essential, as recommended by the American College of Critical Care Medicine 1
Monitoring electrolytes closely, as hypokalemia, hypophosphatemia, hypomagnesemia, and hypocalcemia can develop and precipitate arrhythmias, is crucial, according to the American College of Critical Care Medicine 7
Avoiding rapid rewarming, as rebound hyperthermia worsens outcomes, is recommended by the American College of Critical Care Medicine 7
Targeting normothermia (36-37°C) as the endpoint of rewarming is essential, as recommended by the American College of Critical Care Medicine 2, 3, 4

The American College of Endocrinology states that coagulopathy risk should not be ignored, even at mild hypothermia (34.5°C), as platelet function is already impaired and clotting factor activity begins to decline 1
The American College of Critical Care Medicine advises not to use cold intravenous fluids or rapid IV push of cold saline, as this can worsen hypothermia or cause profound bradycardia 7
The American Heart Association recommends not to assume the patient is dead based on clinical appearance alone—continue resuscitation until rewarmed unless obvious signs of death (rigor mortis, decomposition) are present 6, 5