Cardiac Arrest with Anoxic Brain Injury

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Most CA victims are resuscitated, but they often suffer from post- CA conditions. The most common being neurological damage, which is the leading cause of post-CA disability. The damage can be very severe and varies depending on the amount of time required for circulatory restoration. The longer the brain is without oxygen, the worse the injury to the brain can be. Depending on the degree of brain death it can have a substantial effect on the patient’s ability to perform activities of daily living (ADL) independently. Irreversible brain injury or death can occur in as little as four to six minutes from the onset of arrest, therefore it is important that resuscitation not be delayed or interrupted.

An anoxic injury is the term used to refer to the brain’s disruption of oxygen supply and it is predicted to occur after cardiac arrest while the patient is unconscious. Eighty percent of cardiac arrest victims remain in a coma for more than 48 hours and only twenty percent of those patients will survive and regain consciousness. Factors that increase the chance of developing an anoxic brain injury are patients over seventy years old, history of renal failure or heart conditions, arrest lasting longer than ten minutes before successful resuscitation was achieved, hyperglycemia within the first twenty-four hours, and fever within the first forty-eight hours.

Treatment is keeping the head of the bed elevated, drugs to help with possible seizure activity, and the prevention of nosocomial infections. An additional therapy is the induction of mild hypothermia to a target temperature of thirty-two to thirty-four degrees Celsius for as long as twenty-four hours. This has been found to improve the outcome of patients successfully resuscitated from cardiac arrst.

A serial neurological exam is the most helpful in predicting individual outcome following return of spontaneous circulation (ROSC). The Glasgow coma scale score of less than eight or lack of extensor movement at seventy-two hours suggest poor outcome but are not used as an absolute diagnosis. A CT scan is performed to rule out other causes. Difficulty distinguishing between gray and white matter on the CT scan predicts poor prognosis, especially at the cerebral cortex.

References

Dao-jie, X.,Bin, W., Xuan, Z., Yi, Z., Jui-lin. D., &Ying-wei, W. (2017). General anesthetics protects against cardiac arrest-induced brain injury by inhibiting calcium wave propagation in zebrafish, Molecular Brain, 10-9. 10.1186/s13041-017-0323-x

Green. R.S., & Howes, D. (2005). Hypothermic modulation of anoxic brain injury in adult survivors of cardiac arrest: a review of the literature and an algorithm for emergency physicians. Cjem, 7(1), 42-47.

Grossestreuer, A. V., Gaieski, D.F., Donnino, M. W., Nelson, J. M., Mutter, E.L., Carr, B.G., & Wiebe, D. J. (2017). Cardiac arrest risk standardization using administrative data compared to registry data. PLOS ONE, 12(8), 1-12. Doi: 10.1371/journal.pone.0182864

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