If induced hypothermia is desired following ROSC, patients should be warmed to a core temperature between 32-36 degrees C. In patients with contraindication to this therapy, gradual rewarming to a normal temperature can be achieved. If the patient was hypothermic for over 45 -60 minutes, intravascular hydration would be needed due to concurrent vasodilation that occurs with warming. It is vital that during the continued rewarming process, a keen evaluation of the vitals and hemodynamic parameters is done. There is usually no need for adjunct treatment, such as antibiotics or steroids.

Patients are at risk of hyperkalemia during the warming process, and this condition is associated with poorer outcomes. Treat potassium imbalance per guidelines. Also, be aware that there may be associated alcohol or drug abuse or trauma. These conditions will need management in the post-arrest period. Malnourished patients or those with signs of chronic alcohol abuse should receive thiamine. 

Terminating Resuscitation

All hypothermic patients in arrest should be transferred to a medical facility to provide active warming therapies. Remember that early hypothermia, before hypoxemia, can be protective. All patients should receive CPR while attempts to limit heat loss and techniques for warming are provided. Some patients may be resuscitated even following a long period of hypothermia. Once warming has occurred in the medical facility, it is up to the physician’s judgment and patient factors to determine the length of time before terminating resuscitative efforts. 

Hypothermia associated cardiac arrest versus cardiac arrest occurring in the cold

Since hypothermia can be protective if it occurs before hypothermia, there is a useful distinction to be made. Of course, if hypothermia follows hypoxia, it no longer becomes protective. It is often difficult to determine which came before, so in unclear cases, patients should be treated with full resuscitation efforts and manage according to the level of hypothermia. Hypokalemia may indicate hypothermia rather than hypoxia as the instigator for arrest.