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Hypothermia

Adapted from source

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700 Deaths per year  Mild hypothermia (32-35°C)

 ± Rare mortality

Moderate Hypothermia (29-32°C) ± 21% mortality rate

Severe hypothermia (core below 28°C) ± >80% mortality

US multicenter survey

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Hypothermia

Major cause-exposure to cold

In an urban environment, hypothermia with ± alcohol or illicit drugs,

 ± overdose

 ± psychiatric emergency ± major trauma

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Heat loss

Normal is radiation 60%

Conduction 15%

Convection 15% Respiration and evaporation 10%

Cold water increases heat loss by a factor of 25 times

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Hypothermia causes

Hypopituitarism,

Hypoadrenalism

Hypothyroidism. Hypoglycemia

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Hypothermia causes-

Impared thermoregulation Hypothalamic lesions or dysfunction

CNS trauma, strokes, toxicologic and

metabolic derangements, intracranialbleeding, CNS tumors, and multiple

sclerosis

sepsis

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Hypothermia causes-

Increased heat loss/iatrogenic Erythrodermas- burns or psoriasis

Cold solution infusions (trauma)

Overzealous therapeutic temp lowering

 ± Heat stroke ± Rescussition hypothermia

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Mild hypothermia (32-35°C)

stable hemodynamically

* Lethargy * Confusion

* Shivering

* Loss of fine motor coordination paradoxical undressing

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Moderate hypothermia (28-32°C)

* Delirium

* Slowed reflexes

Osborne waves Slurred speech

ataxia

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Moderate hypothermia 28-32

32°C or lower present in delirium.

31°C or below, the body loses its ability to generate heatby shivering.

30°C, patients become at risk for arrhythmias. Atrialfibrillation and other atrial and ventricular rhythms maypresent. The pulse continues to slow progressively, andcardiac output is reduced.

28-30°C, pupils may become markedly dilated andminimally responsive to light, a condition that can mimicbrain death.

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* Severe hypothermia (<28°C)

* Very cold skin

* Unresponsive * Coma

* Difficulty breathing

* Abnormal heart rhythms

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Severe hypothermia (<28°C)

* At 28°C, the body becomes markedlysusceptible to ventricular fibrillation and further depression of myocardial contractility.

* Rigidity

* Apnea

* No pulse

* Areflexia * Unresponsiveness

* Fixed pupils

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Lab value adjustments

ABG-read the temp corrected values

Hematocrit artifically high (2% for 1º drop)

Potassium unreliable(includes ECG changes of hyperkalemia)

Coagulation

 ± In lab is normal (blood is warmed first) ± In pt, failure of enzyme reactions with DIC

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Imaging

CXR

 ± Common for aspiration pneumonia and

pulmonary edema

CT scans for AMS

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Slow Rewarming

Remove wet clothing

Dry the patient

Blankets, hat, heating lights (0.9C/hr) Warm IV fluids---why bother? (0.3C/hr)

Warm Oxygen!!!! (0.7-1.2C/hr)

Live patient (1C/hr)

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Moderate to Severe

Hypothermia Care Warm the patient

Arrythmia¶s ± ventricular fibrillation

 ± Bretylium ± Lidocaine

 ± 2J/kg of Defib

Lots of CPR ± Little medicines

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Moderate Rewarming

About 3C per hour 

Gastric lavage 45 degree C fluids

Peritoneal lavage 45 degree C fluids ? IV fluids at 65 degrees C

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Really warm quick

Rapid rewarming

 ± Thoracic lavage 500ml/min 6C/hr 

2000

ml/min 20C/hr 

Warm water immersion

 ± Will raise temperature 20-30C in an hour 

 ± Challenge for cardiac monitoring, defib

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When to stop?

Temp above 32 and still dead

Potassium above 10

Frozen chest so CPR impossible

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Dry and Cover the Patient

Endocrine

 ± Hypopituitarism, hypoadrenalism, hypothyroid Hypoglycemia

Sepsis

 ± Fix the sugar 

 ± Glucocorticoids (100-200 Hydrocortisone)

 ± Kill the bugs ± Rewarm as needed