Cold Hearts: A Case Study of Therapeutic Hypothermia in Helicopter Emergency Medical Services (HEMS)

Abstract 

A 36-year-old white man hit a home run in the seventh inning of a community baseball game. The patient ran the bases successfully and returned to home plate. As he was bending over to pick up the bat, he suddenly collapsed. Bystander cardiopulmonary resuscitation (CPR) was immediately initiated, and defibrillation occurred within 5 minutes per the local emergency medical services (EMS) service. The automated external defibrillator (AED) shocked the patient a total of three times, and he was transported to a local hospital at the basic life support level. Helicopter emergency service (HEMS) was activated by local medical control, and LifeFlight of Maine responded to transfer this patient to a tertiary care center.

Case

In the local emergency department, the otherwise healthy athlete was sedated and paralyzed with etomidate and succinylcholine. Subsequent sedation was continued with propofol. The flight team initiated the post-cardiac arrest therapeutic hypothermia protocol with a 30-mL/kg infusion of lactated Ringer's at 4°C. By the time the patient arrived at Eastern Maine Medical Center in Bangor, Maine, he had received 2 liters of the cold fluid. His rectal temperature on arrival was determined to be 35°C. During the next 24 hours, his temperature was maintained at 33°C.

At the conclusion of the 24-hour period, sedation was weaned, and the patient woke up gradually. After extensive evaluation, cardiologists determined that the patient's cardiac arrest occurred secondary to a dysrhythmia. An automatic implantable cardioverter defibrillator was subsequently placed. The patient was discharged on hospital day 9 and returned to work 2 weeks after the event without any neurologic or cardiovascular deficits.