Interventional procedure overview of temperature control to improve neurological outcomes after cardiac arrest

What the procedure involves

After cardiac arrest, people in a coma who have return of spontaneous circulation (ROSC) can have their core body temperature actively controlled to prevent fever (by maintaining normothermia, a normal temperature of 36.5°C to 37.5°C) or induced to therapeutic hypothermia (cooled to a core temperature typically between 32.0°C and 36.0°C). The aim is to reduce brain injury and improve neurological outcomes. The exact mechanism by which cooling protects against brain injury is unknown. Possible mechanisms include reductions in metabolic demand, release of excitatory neurotransmitters and inflammation after ischaemia.

Temperature control is doneusing surface techniques (for example, heat exchange cooling pads, cooling blankets and ice packs), internal techniques (for example, an endovascular cooling device) or a combination of these techniques. Core body temperature is monitored using a temperature probe (such as a bladder, rectal or nasopharyngeal temperature probe) and is controlled to a pre-set point determined by the clinician.

If therapeutic hypothermia is induced, controlled rewarming is usually done over several hours. In addition, people who have had cardiac arrest generally have standard critical care measures together with intravenous sedation and muscle relaxants, to prevent and manage shivering.