Hypothermia 

Definition: core temperature below 35°C 

Types:

1. primary hypothermia due to environmental exposure 
2. secondary hypothermia due to abnormal thermoregulatory mechanisms from underlying altered physiological state. 

Stage:

Management:

Principles:

• rewarm the patient in a controlled manner
• correction of hypoxia (by oxygenation and ventilation if necessary), 
• correction of fluid and electrolyte disturbance
• management of cardiovascular abnormalities. 

Investigation:

• ECG→ J wave arrhythmia
• ABG → 
• CBC high Hct, Electrolytes
• CXR, CK
• LFT
• To find out cause: pituitary, hypothyroidism, adrenal, hypoglycemia, drugs intoxication 

Mild hypothermia 

• warm environment
• warm clothes 
• warm drinks
• active movement 

Moderate hypothermia:

• whole body insulation → Hibler’s method
• external rewarming:

• warm blankets and 
• heat packs 
• warmed intravenous fluids 

• reduce movement, keep horizontal

Severe hypothermia: 

• as for stage 2 (moderate), plus
• more invasive warming methods

1. bladder lavage, which involves flushing the bladder with 300 mL of warm saline 
2. thoracic lavage through two unilateral / single chest drain approach 
3. extracorporeal membrane oxygenation (ECMO) and 
4. cardiopulmonary bypass (CPB) 

• airway support, ventilation, oxygenation
• IV access: fluid and electrolytes 
• management of cardiac arrest:

1. Assessment for signs of life should be extended to 1 minute  
2. VT, VF: defibrillation →if no response after three shocks → additional shocks should be delayed until core temperature is > 30°C 
3. For adjunctive medications (adrenaline, amiodarone etc.) 

• withhold, if the temperature is below 30°C; 
• double the interval between doses when temperature is 30–35°C