Skip to Main Content

+

  • • Uncontrolled lowering of core body temperature below 35 °C by exposure to cold

    • EtOH facilitates induction of hypothermia by producing sedation (inhibiting shivering) and cutaneous dilation

    • Heart is most sensitive organ to cooling and is subject to ventricular fibrillation or asystole when temperature drops to 21-24 °C

++

Epidemiology

+

  • • Elderly patients living alone in inadequately heated homes

    • Alcoholics exposed to the cold during a binge

    • People engaged in winter sports

    • People lost in cold weather

    • Predisposing diseases include:

    • -Myxedema

      -Hypopituitarism

      -Adrenal insufficiency

      -Cerebral vascular insufficiency

      -Mental impairment

      -Cardiovascular disorders

++

Symptoms and Signs

+

  • • Mentally depressed (somnolent, stuporous, or comatose)

    • Cold

    • Pale or cyanotic

    • Shivering absent below 32 °C

    • Slow and shallow respirations

    • Usually normotensive and bradycardic

    • At temperatures < 32 °C, patients may appear to be dead

    • Frostbitten or frozen extremities

++

Laboratory Findings

+

  • • Severe hypoglycemia is common

    • Elevated serum amylase in 50%

    • Elevations of aspartate aminotransferase (AST), lactic dehydrogenase (LDH), and creatine kinase (CK) enzymes

    • ECG shows PR lengthening, pathognomonic J wave at junction of the QRS and ST segment

+

  • • When severely hypothermic, patients should not be declared dead until measures for rewarming and resuscitation have failed

    • Mild hypothermia (32-35 °C) can be treated by passive rewarming with continuous monitoring of rectal or esophageal temperatures

    • Active rewarming is indicated for temperatures below 32 °C, cardiovascular instability, or failure of passive rewarming

    • Methods for rewarming include:

    • -Immersion in warm water

      -Inhalation of heated air

      -Pleural and peritoneal lavage

      -Extracorporeal blood warming

+

  • • Physical exam

    • Temperature

    • ECG

    • Central venous pressure and pulmonary capillary wedge pressure should be kept below 12-14 cm H20 to minimize edema

+

  • • Immersion in warm water (40-42 °C) will raise body temperature 1-2 °C per hour

    • Pleural irrigation via 2 right thoracostomy tubes (anterior, posterior) with warm saline (40-42 °C)

    • Peritoneal lavage involves giving warm (40-45 °C) crystalloid solutions at 6 L/h which will raise temperature 2-4 °C per hour

    • Partial cardiopulmonary bypass (CPB) is the most efficient technique and is indicated for ventricular fibrillation, severe hypothermia, or frozen extremities

    • Partial CPB with flows of 6-7 L/min can raise core temperature 1-2 °C every 3-5 minutes

    • Endotracheal intubation and mechanical ventilation are often necessary

    • Bretylium tosylate 10 mg/kg is best drug for ventricular fibrillation

    • Antibiotics are often indicated for pneumonitis

    • Hypoglycemia should be treated with IV D50

++

Treatment Monitoring

+

  • • Continuous temperature monitoring

    • Careful observation for unsuspected disease masked by hypothermia

++

Complications

+

  • • Increased capillary permeability may lead to generalized and pulmonary edema upon rewarming

    • Coagulopathies (including disseminated intravascular coagulation) are seen occasionally

    • Pancreatitis and acute renal failure (ARF) common in < 32 °C

    • Failure to respond to treatment should suggest adrenal insufficiency

    ...

Want remote access to your institution's subscription?

Sign in to your MyAccess profile while you are actively authenticated on this site via your institution (you will be able to verify this by looking at the top right corner of the screen - if you see your institution's name, you are authenticated). Once logged in to your MyAccess profile, you will be able to access your institution's subscription for 90 days from any location. You must be logged in while authenticated at least once every 90 days to maintain this remote access.

Ok

About MyAccess

If your institution subscribes to this resource, and you don't have a MyAccess profile, please contact your library's reference desk for information on how to gain access to this resource from off-campus.

Subscription Options

AccessSurgery Full Site: One-Year Subscription

Connect to the full suite of AccessSurgery content and resources including more than 160 instructional videos, 16,000+ high-quality images, interactive board review, 20+ textbooks, and more.

$995 USD
Buy Now

Pay Per View: Timed Access to all of AccessSurgery

24 Hour Subscription $34.95

Buy Now

48 Hour Subscription $54.95

Buy Now

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.