Cooling procedure after cardiac resuscitation aids recovery
Many people who survive cardiac resuscitation suffer long-term neurologic deficits. The latest research reveals that brain injury following cardiac resuscitation results from free radical damage to blood vessels in the brain and other organs in the hours following CPR. Within the past two decades, researchers have found that cooling the core body temperature after resuscitation lowers the metabolism and results in a doubling of survival and less damage to the brain.
This protocol is called therapeutic hypothermia. When such a patient is cooled to approximately 32 C for 24 hours post resuscitation, then slowly rewarmed, the patient is more than twice as likely to recover full brain function than if they don't have this treatment. Fortunately, most hospitals in Arizona have the technology to perform therapeutic hypothermia.
Therapeutic hypothermia buys time for physicians so they are able to determine the cause of the cardiac arrest and correct the problem. During this time, the patient may require stent placement, if the coronary arteries are blocked. Patients like this are in critical condition, usually in a coma, and it may require 3-7 days before they wake up.
Future directions of this research are truly revolutionary. If physicians can't get the heart to start beating again, ECPB, also called cardiopulmonary bypass can be used to oxygenate the blood while the heart is resting. For this procedure, blood is removed from a vein and reoxygenated, then reinserted into an artery. In one study in California, 70 percent of patients treated with ECPB survived and were discharged from the hospital with good neurologic function.
Another procedure that is showing promise is called suspended animation. This protocol is used for patients who have had massive wounds and loss of most their blood volume such as might happen after gunshot wounds. Suspended animation requires the patient to be cooled much more quickly and much lower than with therapeutic hypothermia. Dog studies have suggested that physicians may have at least one hour to repair damage to organs, and afterwards rewarm the patient to full neurologic function.
It's important to remember that early CPR and defibrillation with AED is vitally important to begin as soon as possible after cardiac arrest, so that these patients have the best chance of survival.
For most of history, the interface between life and death has been a singular point in time. But with these new technologies, the time of cardiac arrest and resuscitation has been extended to hours and even days. Nowadays, a patient dies only when physicians stop making efforts to revive them. Predicting neurologic recovery is not easy especially in the first three days after cardiac arrest. Electroencephalograms, blood tests and physical exams are not accurate enough within the first three days. Therefore, it's important to not rush any life-ending decisions for up to a week after such an event since the brain takes time to recover from such a shock.
Robin Fleck, M.D., is a board-certified dermatologist and internist. She is founder and medical director of Vein Specialties and Body Oasis Medical Spa, and is the director of Southwest Skin and Cancer Institute. Send questions via rejuvadoc.com.