Hypothermia

Question 1

Definition

Answer 1

Occurs when body loses heat faster than it can produce it , causing a dangerously low body temperature.
- Typically due to prolonged exposure to low temperatures.

Question 2

Hypothermia is defined as…

Answer 2

Mild: 35-32°C
Moderate: 32-28°C
Severe: <28°C

Question 3

Epidemiology

Answer 3

• Older adults: particularly occurs with inadequate eating and heating, or inappropriate clothing
• Babies: newborns lack the abilities to shiver.

Question 4

Risk factors

Answer 4

• Poorly dressed or sleeping in cold bedrooms
• Prolonged outdoor stays: hikers, hunters and the homeless
• People who drink alcohol or use illicit drugs
• Immersion in cold water
• Sepsis
• Hypothyroidism
• Hypoglycaemia
• Adrenal insufficiency

Question 5

Signs

Answer 5

• Shivering
• Weak, slow pulse
• Cold, pale skin: skin and lips may turn blue or grey
• Reduced GCS
• fixed dilated pupils: in severe Px may appear dead…

Question 6

Symptoms

Answer 6

• Slurred speech
• Slow, shallow breathing
• Lack of co-ordination
• Drowsiness

Question 7

Investigations

Answer 7

• CONFIRM DX: Core temperature measurement: assess the severity of hypothermia
• Blood tests:
  = electrolytes,
  = LFT’s,
  = coagulation profile,
  = blood glucose
• ECG:
  = widening of QRS,
  = prolonged PR and QT
  = and J (Osborn) waves.
  = Risk of ventricular fibrillation occurs <28°C

Question 8

Treatment

Answer 8

FIRST LINE:
- Mild: Passive rewarming
- Mod: Active external rewarming
- Supportive care: treat underlying cause e.g sepsis
SECOND LINE:
- Severe: Active internal warming:
= warm IV fluids,
= warm humidified O2,
= bladder lavage with warm fluids
= ECMO

Question 9

Complications

Answer 9

• Freezing of body tissues : frostbite occurs in the extremities due to poor circulation and freezing. It can lead to death of tissue and require amputation.
• Hypothermia-induced cardiac arrhythmias: hypothermia is one of the reversible causes of cardiac arrest and may require prolonged resuscitation attempts as the patient is warmed. Professionals should recall “not dead, until warm dead”.
• Respiratory failure
• Cold diuresis
• Rhabdomyolysis: and associated AKI