Emergency Management of Hypothermia- Warning Signs, First-Aid Measures, and Treatment

Introduction:

Hypothermia is an abnormally low body temperature (a core body temperature lower than 35 degrees Celsius). Severe hypothermia significantly contributes to approximately 600 deaths yearly in the United States. Hypothermia also affects the brain and heart function and notably impacts the mortality risk in nerve, brain, and heart disorders. The symptoms of hypothermia include shivering, lethargy, confusion, and coma. These can be fatal. Prompt management of hypothermia is essential to save lives.

What Are the Causes of Hypothermia?

The person becomes hypothermic when the body’s heat loss exceeds heat production. The common causes of hypothermia include:

1. Cold weather.

2. Contact with a cool surface for a long period of time.

3. Prolonged immersion in cold water (swimming pools).

4. Wet clothing.

5. Cold and wet wind.

6. Conditions that cause immobility and unconsciousness, such as:

   • Trauma.

   • Hypoglycemia (low blood sugar levels).

   • Seizure disorders.

   • Stroke.

   • Intoxication (drug or alcohol).

7. Old age (due to impaired mobility, communication, or temperature sensation, older people tend to remain in an overly cold place for longer duration).

8. Very young age (babies and toddlers) exposed to extremely cold environments.

What Are the Warning Signs of Hypothermia?

As the body temperature decreases, all the physiologic functions, including heart, lung, nerve, brain, kidney, metabolism, and reflexes, slow down. The body’s ability to control body temperature ceases below 30 degrees Celsius, after which only external heat sources can help the patient rewarm. Kidney dysfunction in hypothermia results in decreased fluid in the blood (blood volume decreases) and can cause sudden shock or cardiac arrest during rewarming. Thus, hypothermia must be promptly managed with emergency medical care. The common signs and symptoms of hypothermia include:

• Shivering.

• Confusion.

• Memory loss.

• Slurred speech.

• Drowsiness.

• Exhaustion

• Numbness in hands and feet.

• Unconsciousness.

• Shallow breathing.

• Hallucinations.

• Coma.

• Unreactive pupils.

• Slow heartbeat.

• Babies show very low energy levels and cold, bright red skin.

What First Aid Can Be Given for Hypothermia?

Hypothermia is a medical emergency that requires immediate action. The first aid depends upon the severity of hypothermia and the presence of other complications, such as cardiac arrests. If you suspect a person is hypothermic, check the person’s temperature. If the patient’s temperature is less than 35 degree Celsius, do the following:

1. Immediately call for emergency medical help.

2. Slowly try to restore warmth.

3. Initiate measures to prevent further heat loss.

4. If possible, shift the patient indoors or to a warmer area.

5. If the patient’s clothes are wet, remove them and ensure the patient is dry.

6. Do not warm the patient’s feet or hands first, as the patient might go into shock (sudden drop in blood flow through the body). Warm the patient’s chest, neck, head, and groin first.

7. Wrap warm, electric, or dry clothing on the patient and insulate them. To rewarm, you can also establish skin-to-skin contact under the dry and loose layers of clothing or sheets.

8. Do not immerse the patient in warm water. This would cause rapid warming and cause the patient’s heart to flutter rapidly, leading to a heart arrest.

9. Do not apply hot packs (hot water bottles or chemical hot packs) directly to the patient. Instead, wrap them in cloth and use them to rewarm.

10. If the patient is conscious, give them warm fluids to drink. Avoid alcohol and caffeine. Do not try to provide warm fluids to unconscious patients.

11. Once the patient’s body temperature rises, keep them dry and wrapped. Make sure the patient’s neck and head are covered as well. For stable patients, rewarming at one-degree Celsius per hour is acceptable.

12. Hypothermia can affect the patient’s breathing, respiratory rate, and pulse. Immediately start cardiopulmonary resuscitation if the patient stops breathing.

13. Continue cardiopulmonary resuscitation till the patient starts breathing properly or until emergency medical help arrives. Continue warming the patients while performing cardiopulmonary resuscitation. It is possible to successfully resuscitate hypothermia patients who appear dead (pulse not detectable, cold, and collapsed).

14. Continue warming efforts. Once the emergency medical personnel arrive, they will continue warming the patient and administer warm moist oxygen and intravenous fluids.

What Are the Treating Methods for Hypothermia?

The treatment for hypothermia depends upon its severity. The various treatment options to manage hypothermia include:

1. Passive Rewarming: In case of mild hypothermia, a temperature between 32.2 degrees Celsius, good thermoregulation, warm fluids, and heated blankets are sufficient to rewarm the patient.

2. Active Rewarming: Active rewarming is performed if the patient’s core temperature is lesser than 32.2 degree Celsius. At such low temperatures, the heart function becomes unstable. In addition, active rewarming is done in other scenarios, including certain hormone insufficiencies, hypothermia due to toxicity, trauma, or other predisposing conditions. It is considered moderate hypothermia when the core body temperature is between 28 and 32.2 degree Celsius. For such patients, external heat with hot air is used (should be first applied to the chest or thorax to prevent increased metabolic demands)

3. Core Rewarming: It is considered severe hypothermia when the core body temperature is less than 28 degree Celsius. Core-rewarming interventions are performed in severe hypothermia, especially in patients with low blood pressure and cardiac arrests. These include:

• Inhalation of Heated and Moist (Humidified) Oxygen:

  • The warm moist oxygen is supplied through oxygen masks or tubes in the airway.

  • It prevents heat loss during breathing.

  • It can add one to two degrees Celsius per hour to the rewarming rate.

• Intravenous warm crystalloids or blood infusions can help with large-volume fluid resuscitations.

• Lavage Using Two Chest Tubes: Warm saline is infused through one chest tube and drained through another tube. This invasive procedure is very effective in raising the core temperature.

• Extracorporeal Core Rewarming: These invasive procedures help rewarm core blood rapidly and effectively. Appropriate specialists perform it. There are five types of extracorporeal core rewarming procedures:

  • Hemodialysis.

  • Venovenous.

  • Continuous arteriovenous.

  • Cardiopulmonary bypass.

  • Extracorporeal membrane oxygenation.

4. Cardiopulmonary Resuscitation: When cardiac arrest with shockable rhythms is confirmed, intubation and cardiopulmonary resuscitation are done. Advanced life support is continued until the body temperature reaches 32 degrees Celsius. Resuscitation is withheld until a cardiac arrest is confirmed, as the symptoms may resolve with rewarming. Drugs used in advanced life-support are administered with care.

Key points:

• Hypothermia is an abnormally low body temperature of less than 35 degree Celsius.

• It is a medical emergency that requires prompt treatment.

• Symptoms depend on the cause and severity of hypothermia. They can range from shivering, lethargy, and confusion to unconsciousness and coma.

• Mild decreases in core body temperature are treated with simple rewarming measures such as insulating blankets and a warm environment.

• Immediately call for emergency medical services if the patient has moderate to severe hypothermia, which can lead to cardiac arrests and death.

• Severe hypothermia is treated with forced air-warming and active rewarming, heated infusion, inhalation, lavage, extracorporeal rewarming, and cardiopulmonary resuscitation (for cardiac arrests).