8/8/2019 Hypothermia Edited
http://slidepdf.com/reader/full/hypothermia-edited 1/21
Hypothermia
Adapted from source
8/8/2019 Hypothermia Edited
http://slidepdf.com/reader/full/hypothermia-edited 2/21
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
8/8/2019 Hypothermia Edited
http://slidepdf.com/reader/full/hypothermia-edited 3/21
Hypothermia
Major cause-exposure to cold
In an urban environment, hypothermia with ± alcohol or illicit drugs,
± overdose
± psychiatric emergency ± major trauma
8/8/2019 Hypothermia Edited
http://slidepdf.com/reader/full/hypothermia-edited 4/21
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
8/8/2019 Hypothermia Edited
http://slidepdf.com/reader/full/hypothermia-edited 5/21
Hypothermia causes
Hypopituitarism,
Hypoadrenalism
Hypothyroidism. Hypoglycemia
8/8/2019 Hypothermia Edited
http://slidepdf.com/reader/full/hypothermia-edited 6/21
Hypothermia causes-
Impared thermoregulation Hypothalamic lesions or dysfunction
CNS trauma, strokes, toxicologic and
metabolic derangements, intracranialbleeding, CNS tumors, and multiple
sclerosis
sepsis
8/8/2019 Hypothermia Edited
http://slidepdf.com/reader/full/hypothermia-edited 7/21
Hypothermia causes-
Increased heat loss/iatrogenic Erythrodermas- burns or psoriasis
Cold solution infusions (trauma)
Overzealous therapeutic temp lowering
± Heat stroke ± Rescussition hypothermia
8/8/2019 Hypothermia Edited
http://slidepdf.com/reader/full/hypothermia-edited 8/21
Mild hypothermia (32-35°C)
stable hemodynamically
* Lethargy * Confusion
* Shivering
* Loss of fine motor coordination paradoxical undressing
8/8/2019 Hypothermia Edited
http://slidepdf.com/reader/full/hypothermia-edited 9/21
Moderate hypothermia (28-32°C)
* Delirium
* Slowed reflexes
Osborne waves Slurred speech
ataxia
8/8/2019 Hypothermia Edited
http://slidepdf.com/reader/full/hypothermia-edited 10/21
8/8/2019 Hypothermia Edited
http://slidepdf.com/reader/full/hypothermia-edited 11/21
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.
8/8/2019 Hypothermia Edited
http://slidepdf.com/reader/full/hypothermia-edited 12/21
* Severe hypothermia (<28°C)
* Very cold skin
* Unresponsive * Coma
* Difficulty breathing
* Abnormal heart rhythms
8/8/2019 Hypothermia Edited
http://slidepdf.com/reader/full/hypothermia-edited 13/21
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
8/8/2019 Hypothermia Edited
http://slidepdf.com/reader/full/hypothermia-edited 14/21
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
8/8/2019 Hypothermia Edited
http://slidepdf.com/reader/full/hypothermia-edited 15/21
Imaging
CXR
± Common for aspiration pneumonia and
pulmonary edema
CT scans for AMS
8/8/2019 Hypothermia Edited
http://slidepdf.com/reader/full/hypothermia-edited 16/21
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)
8/8/2019 Hypothermia Edited
http://slidepdf.com/reader/full/hypothermia-edited 17/21
Moderate to Severe
Hypothermia Care Warm the patient
Arrythmia¶s ± ventricular fibrillation
± Bretylium ± Lidocaine
± 2J/kg of Defib
Lots of CPR ± Little medicines
8/8/2019 Hypothermia Edited
http://slidepdf.com/reader/full/hypothermia-edited 18/21
Moderate Rewarming
About 3C per hour
Gastric lavage 45 degree C fluids
Peritoneal lavage 45 degree C fluids ? IV fluids at 65 degrees C
8/8/2019 Hypothermia Edited
http://slidepdf.com/reader/full/hypothermia-edited 19/21
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
8/8/2019 Hypothermia Edited
http://slidepdf.com/reader/full/hypothermia-edited 20/21
When to stop?
Temp above 32 and still dead
Potassium above 10
Frozen chest so CPR impossible
8/8/2019 Hypothermia Edited
http://slidepdf.com/reader/full/hypothermia-edited 21/21
Dry and Cover the Patient
Endocrine
± Hypopituitarism, hypoadrenalism, hypothyroid Hypoglycemia
Sepsis
± Fix the sugar
± Glucocorticoids (100-200 Hydrocortisone)
± Kill the bugs ± Rewarm as needed