Delay in hypothermia, ROSC linked with poor post cardiac arrest neurologic outcomes

Delay in initiation of therapeutic hypothermia and delay in return of spontaneous circulation (ROSC), evidenced by a palpable pulse or a measurable blood pressure, were both associated with poor neurologic outcomes in post cardiac arrest patients, according to a study being presented Nov. 14 at the at the American Heart Association (AHA) scientific sessions in Orlando, Fla. Also, caregivers who have an appropriate understanding of the patient's post cardiac arrest neurologic state could ensure better patient management at discharge.

The researchers were seeking to determine whether there were differential rates of neurologic outcomes in post cardiac patients by time to initiation, depth and duration of therapeutic hypothermia. They based the neurologic outcomes on the Cerebral Performance Category (CPC), which is ranked from 1 to 5, with 1 identified as "good," and 3 to 5 identified as poor.

"Previous studies have collapsed several CPC scores together, namely CPC 1 and 2. CPC 1 indicates the patient is conscious, alert and able to work, with only mild neurologic and psychological deficit, while with CPC 2, the patient still has sufficient cerebral function for independent activity and able to sheltered environment," explained Susan Sendelbach, RN, of the Minneapolis Heart Institute- at Abbott Northwestern Hospital in Minneapolis and researcher with Minneapolis Heart Institute Foundation.

"When you are planning discharge for patients, there is big difference between 'able to work' and 'able to work in a sheltered environment,' which really should change how we plan for discharge," she added.

Therefore, through this study, Sendelbach and her colleagues sought to further break down how the nuances of the CPC score could impact the patient and the discharge process-particularly through the separation of CPC 1 and CPC 2. Thus, they examined CPC 1, CPC 2 and CPC 3-5 independently. "We wanted to understand how the temperature management of these patients impact their neurologic outcomes," she said.

The researchers conducted a secondary data analysis from the Minneapolis Heart Institute- data entered into the International Cardiac Arrest Registry (INTCAR) database in 172 adult patients who had experienced an out-of-hospital cardiac arrest undergoing therapeutic hypothermia.

The found that only two variables associated with good versus poor outcome among patients at time of ICU discharge:

• For every five minute delay in initiating hypothermia treatment, there was a 3 percent greater odds of the patient having a poor outcome compared to a good outcome.
• For every five minutes delay in the patient having ROSC, there is a 33 percent greater odds of the patient having a poor versus a good outcome in crude models.

"These data would support that you need to start therapeutic hypothermia as soon as possible, in addition to attempting to reach goal temperature as soon as possible in order to preserve neurologic outcomes," Sendelbach concluded.