Hypothermia Management

Aka: Hypothermia Management

1. See Also
   1. Hypothermia
   2. Hypothermia Management in the Wilderness
2. Management
   1. General
      1. Avoid measures that provoke arrhythmias (see below)
      2. Remove wet clothing and apply warm blankets
   2. Empiric antibiotics if Sepsis suspected
      1. Elderly
      2. Neonatal Sepsis
      3. Immunocompromised patients
   3. Empiric therapies
      1. Thiamine if Alcohol Abuse suspected
      2. Dextrose if Glucose testing not immediately available
      3. Do not use empiric Corticosteroids
         1. Only indicated in suspected Adrenal Insufficiency
         2. May be used if refractory to all other measures
   4. Cardiovascular assessment
      1. Avoid measures that provoke arrhythmia
         1. Avoid excessive movement
         2. Avoid Nasogastric Tube
      2. Check pulse
         1. Palpate for pulse for 45 seconds before CPR
         2. Use doppler Ultrasound if unable to palpate
      3. Ventricular Fibrillation
         1. Defibrillation
         2. Withold medications until temperature >86 F (30 C)
            1. Follow ACLS guidelines once temperature >86 F
      4. Other arrhythmias
         1. Most non-lethal arrhythmias resolve with rewarming
   5. Rewarming
      1. Hypothermia without cardiopulmonary arrest
         1. Passive external rewarming
            1. May be all that is needed if core >89.6 F (32 C)
         2. Minimally-invasive active rewarming
            1. Warmed IV fluids
            2. Warmed, humidified oxygen
         3. Consider active external rewarming
            1. Forced air warming systems are preferred
      2. Hypothermia with cardiopulmonary arrest
         1. ABC Management
         2. Intubation
         3. Defibrillation for Ventricular Fibrillation
         4. Minimally-invasive active rewarming
            1. Warmed IV fluids
            2. Warmed, humidified oxygen
         5. Invasive active rewarming
            1. Extracorporeal rewarming is preferred
            2. If extracorporeal not available
               1. Use other invasive technique in combination
         6. Empiric therapies as above if indicated
         7. Advance therapy when core temp >86-89.6 F (30-32 C)
            1. Institute full ACLS guidelines with medications
3. Management: Passive Rewarming
   1. Indications
      1. Mild Hypothermia
      2. Relies on intact energy and Thermoregulation
   2. Technique
      1. Move the patient to warm, dry environment
      2. Remove wet clothing
      3. Apply warm blankets
4. Management: Active external rewarming
   1. Indication
      1. Mild Hypothermia
      2. Relies on intact circulation
      3. Rewarm core first (as below) in serious cases
         1. Otherwise risk of adverse effects as below
   2. Technique
      1. Apply hot water bottles or heating pads to trunk
      2. Forced-air warming systems (e.g. Bair Hugger)
         1. Preferred option in active external warming
         2. Least likey to cause adverse effects below
      3. Arteriovenous anastomosis reheating
         1. Hands immersed in 113 F (45 C) water or
         2. Device encloses Forearm in heated air at -40 mmHg
   3. Adverse effects
      1. General
         1. Patient may appear to worsen before improving
         2. Do not stop rewarming prematurely
         3. Rewarm core first in serious cases
         4. Least adverse effects with forced air rewarming
      2. Core temperature afterdrop
         1. Results from cold peripheral blood return
      3. Rewarming acidosis
         1. Redistribution of pooled peripheral Lactic Acid
      4. Peripheral vasodilation (Rewarming shock)
         1. Venous peripheral pooling
5. Management: Minimally invasive active core rewarming
   1. Airway rewarming
      1. Humidified oxygen at 104-113 F (40-45 C)
      2. Increases core temp by 1.8-4.5 F (1.0-2.5 C)/hour
   2. Intravenous fluids
      1. D5NS at 104-113 F (40 C to 45 C)
      2. Heat in blood warmer or calibrated microwave
6. Management: Invasive active core rewarming
   1. Extracorporeal blood warming
      1. Raises core temp by 1.8 - 3.6 F (1-2 C) q5 min
      2. Modalities
         1. Cardiopulmonary bypass
         2. Arteriovenous or venovenous rewarming
         3. Hemodialysis
   2. Body cavity rewarming
      1. Indicated if extracorporeal warming not available
      2. Raises core temp by 1.8 - 2.7 F (1-1.5 C)/hour
      3. Modalities
         1. Gastric Lavage
         2. Colonic lavage
         3. Bladder lavage
   3. Peritoneal Dialysis
      1. Indicated if extracorporeal warming not available
      2. Raises core temp by 1.8 - 5.4 F (1-3 C)/hour
      3. Technique
         1. Instill fluid 104-113 F (40 C to 45 C)
         2. Fluid administered at 6-10 liters/hours
         3. Fluid options
            1. Normal saline
            2. Lactated ringers
            3. Dialysate solution
   4. Closed thoracic lavage
      1. Heated normal saline
      2. Administered via Chest Tubes
         1. In: Midaxillary Thoracostomy tube
         2. Out: Midclavicular Thoracostomy tube
   5. Open thoracic lavage
      1. Direct lavage after thoracotomy
      2. Increases core temp by 14.4 F (8 C)
7. References
   1. Danzl in Marx (2002) Rosen's Emergency Med, p. 1979-96
   2. Danzl in Auerbach (2001) Wilderness Med, p. 135-77
   3. McCullough (2004) Am Fam Physician 70:2325-32