Hypothermic Cardiac Arrest
Introduction
Hypothermic cardiac arrest is a distinct clinical problem. Progressive cooling causes bradyarrhythmias, reduced drug responsiveness, coagulopathy and profound CNS depression.
Rewarming is the definitive therapy and may be lifesaving even after prolonged arrest; management therefore modifies standard ALS in predictable ways (defibrillation and drugs are less effective at low temperatures, prolonged resuscitation and extracorporeal rewarming are often indicated).
Use Resuscitation Council UK (RCUK) guidance for local protocols and ECPR indications (RCUK special‑circumstances and post‑resuscitation guidance).
Physiology and staging
Core temperature correlates closely with physiological state and guides management. If core temperature cannot be measured immediately, use the Swiss clinical stages (I-IV) to estimate severity and act conservatively.
Key temperature ranges and typical findings
Swiss staging (useful when core temperature is unavailable)
- Stage I: Conscious and shivering (mild hypothermia).
- Stage II: Impaired consciousness but still shivering.
- Stage III: Unconscious but with vital signs present.
- Stage IV: No signs of life (cardiac arrest).
Core-temperature measurement - practical points
Accurate core temperature determines staging and many treatment decisions. Use a low‑reading core thermometer where available.