The Swiss hypothermia staging system with recommendations for management
| HT stage | Clinical signs | Core temperature | Management | Hospital triage |
|---|---|---|---|---|
| HT I Mild hypothermia | Conscious and shivering. | 35–32°C | ▸ Active movement and mobilisation ▸ Supply warm and sweetened fluids ▸ Insulate and protect from the elements. | Nearest hospital with emergency department. |
| HT II Moderate hypothermia | Reduced consciousness and not shivering. | <32–28°C | ▸ Gentle extrication and horizontal immobilisation. ▸ Establish ECG and core temperature monitoring. ▸ Apply active external warming to chest, axillae and back. ▸ Administer oxygen. ▸ Obtain intravenous or intraosseous access without delaying transport. ▸ Insulate and protect from the elements. | Stable haemodynamics: ▸ Hospital with active rewarming capability. Unstable haemodynamics: ▸ Triage to hospital with ECMO/CPB capability for circulatory support and rewarming. |
| HT III Severe hypothermia | Unconscious and not shivering but vital signs are present. | <28–24°C | As above plus ▸ Airway management: Recovery position or advanced airway management. ▸ Avoid depolarising agents (Possible hyperkalaemia). ▸ Carefully dose or withhold drugs. | Stable haemodynamics: ▸ Hospital with active rewarming capability. Unstable haemodynamics: ▸ Triage to hospital with ECMO/CPB capability for circulatory support and rewarming. |
| HT IV Profound hypothermia | No vital signs. | <24°C | As above plus ▸ Standard CPR. ▸ Avoid excessive attempts at defibrillation. | Triage to hospital with ECMO/CPB circulatory support and rewarming. |
Adapted from Brugger et al36 and Durrer et al.72 In avalanche victims the clinical presentation of hypothermia may be distorted by the possible coexistence of trauma and asphyxia.
CPB, cardiopulmonary bypass; CPR, cardiopulmonary resuscitation; ECMO, extracorporeal membrane oxygenation.