FN: Hypothermia

Question 1

Definition

Answer 1

Core (rectal) temperature

Question 2

Pathophysiology 4 wats to loose heat

Answer 2

1. Radiation: 60% - infra-red emissions
2. Conduction 15%: primary menas in cold water immersion
3. Convection: 15% removes warmed air from around the body e.g. windy conditions
4. Evaporation 10% - removal of warmed water, increased in dry, windy environments

Question 3

Aetiological classification

Answer 3

Primary: envirnmental exposure
Secondary: change in temperature set-pont e.g. age-related, hypothyroidism, autonomic neuropathy

Question 4

Presentation mild

Answer 4

32. 2-35 degrees
    - shivering
    - tachycardic
    - vasoconstriction
    - apathy

Question 5

Presentaiton moderate

Answer 5

28-32.2 degrees

• dysrhythmia, bradycardia, hypotension
• J waves
• reduced reflexes, dilated pupils, reduced GCS

Question 6

Presentaiton severe

Answer 6

VT-VF- Cardiogenic shock

• Apnoea
• Non-reactive pupils
• Coagulopathy
• Oliguria
• Pulmonary oedema

Question 7

Investigations

Answer 7

1. Rectal/ear temperature
2. FBC, U+E, glucose
3. TFTs, blood gas
4. ECG

Question 8

ECG changes in hypothermia

Answer 8

J waves: between QRS and T wave

Arrhythmias

Question 9

Management

Answer 9

• Cardiac monitor
• Warm IVI 0.9% NS
• Urinary catheter
• Consider Abx for prevention of pneumonia - routine if temp 65yrs

Question 10

Slowly rewarming process

Answer 10

• reheating too quickly: peripheral vasodilatation and shock
• Aim for 0.5 degrees/hr
• Passive external: blankets, warm drinks
• Active external: warm water or warmed air
  Active external: mediastinal lavage and CPB - severe hypothermia only

Question 11

Complications

Answer 11

Arrhythmias
Pneumonia
Coagulopathy
Acute renal failure