Fans of television medical dramas like ER have watched this scene over and over: a person in cardiac arrest is resuscitated with cardiopulmonary resuscitation (CPR), and wakes up good to go. No lasting damage, besides a big scare. But physicians at Mayo Clinic wanted to know if these survivors were really OK. Or could a possible lack of oxygen to the brain during the arrest affect their mental function?
Most research on outcomes after cardiac arrest has focused on the ability to perform daily activities, not on cognitive abilities. Yet, memory and similar complaints are common among patients surviving cardiac arrest.
So a research team from the Mayo Clinic campus in Minnesota set out to find an answer, and results from a small study were presented at the annual meeting of the American Academy of Neurology on April 30, 2009. The physician-researchers contacted 19 patients at various times (five months to two years) after surviving a resuscitation. They assessed these patients' cognitive abilities, and found that while 37 percent of participants demonstrated significant cognitive impairment, 42 percent were deemed to be proficient. The remaining patients were either borderline proficient or couldn't complete the study for other reasons.
The study's lead investigator, Alejandro Rabinstein, M.D., concluded that full cognitive recovery is both possible and fairly common after resuscitation for cardiac arrest. We consider having a significant percentage of patients surviving with no evidence of cognitive impairment to be a good outcome, he says.