HYPOTHERMIA

DESIGNATION OF CONDITION

Mild hypothermia is considered when core body temperature is between 94° and 97° F (34-36° C) and a core temperature between 86 and 94° F (30-34° C) is considered moderate hypothermia. Patients with mild to moderate hypothermia may exhibit signs and symptoms of shivering, tachycardia, tachypnea, decreasing LOC, lethargy (may be fully oriented), and loss of fine motor coordination. Severe hypothermia is considered a core temperature < 86° F (30° C) with signs and symptoms of pupil dilation, bradycardia, bradypnea, coma, no shivering, arrhythmia, and joint stiffness.  Local hypothermia-frost nip and frost bite are generally not treated in the field.  Thawing should be done under controlled conditions and is painful.  Complete re-warming requires prolonged active heating and is seldom done in the field.  Partial re-warming is worse than none.
To change Celsius to Fahrenheit: 1.8 x C degree + 32) example: 30 degrees C = 86 degrees F.

EMPHASIS ON PATIENT CARE
For generalized hypothermia maintain body heat, airway management. For local hypothermia protect the injured area from injury, avoid pressure, trauma, or friction to the area, uncover protected parts from clothing, do not rub, and do not break blisters.  Initiate rapid transport. LOC is the most reliable indicator of the severity of hypothermia.

FIRST RESPONDER AND BASIC PRE-HOSPITAL MANAGEMENT
1. Initial Management - Assess airway, breathing and circulation and manage as indicated.

• Remove patient from the environment.
• Remove all wet clothing.

2. Focused H&P - History, physical exam, vital signs. Check BGL.

3. Managing mild to moderate hypothermia.

• Administer warmed, humidified oxygen titrated to patient condition. If patient becomes hypoxic, administer high concentration or assist ventilations as needed.
• Record oxygen saturation reading.
• Avoid rough handling when moving the patient.
• Cover with blankets, preferably warmed.
• Monitor the patient’s vital signs closely

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4. Managing severe hypothermia includes:

• Assess for pulse and breathing for 30 - 45 seconds.
• Wrap torso, and head in warm blankets. Cover extremities with un-warmed blankets.
• Assist ventilation at 6-10 per minute with warmed, humidified oxygen.
• Handle gently because rough handling may induce fatal cardiac dysrhythmias.
• If the patient is pulseless and apneic:
  • Begin CPR prior to defibrillation and ventilate with warm, humidified oxygen.
  • If patient is in ventricular fibrillation, defibrillate per AHA Protocols.
  • If no conversion, then continue CPR.
  • Consider inserting advanced airway (follow Airway Management Protocols).
  • Ventilate with warmed, humidified oxygen at high concentration.
  • Prevent further heat loss. Do not attempt re-warming in the field, patients re-warmed after severe hypothermia commonly develops cardiac arrhythmia's that must be addressed with ACLS treatment.
  • Monitor the patient’s vital signs closely.

INTERMEDIATE and PARAMEDIC PRE-HOSPITAL MANAGEMENT

5. En-route, initiate a large bore IV of warm/tepid isotonic solution and infuse at a rate to maintain adequate vital signs (only with mild to moderate hypothermia). In severe hypothermia IV fluid administration should be done with caution to avoid after-drop effect of circulating acidotic/toxic peripheral blood to the heart and brain.

6. Airway management should be limited to basic manual procedures and slow ventilatory assistance. If unable to manage the airway by basic maneuvers, adjuncts may be used, however this may induce ventricular dysrhythmias and overzealous ventilatory assistance can induce hypocapnia, resulting in ventricular irritability.
Paramedics should monitor cardiac rhythm.

Note: Subsequent defibrillations or additional cardiac life support medications should be avoided until the patient has been re-warmed in the emergency department. Warm the patient’s core first to avoid after-drop effect. Ventilating patient via mouth to mask may be the most effective core warming device available pre-hospital.