February 24, 2022

Treating Rhythmic and Periodic EEG Patterns in Comatose Survivors of Cardiac Arrest.

Summarized by: 

Mazen Kherallah

Between 10 and 35% of comatose survivors of cardiac arrest have rhythmic and periodic electroencephalographic patterns that could reflect electrographic seizures. The question is whether aggressively treating these patterns with anti-seizure medications could improve neurologic outcomes.

In this open label, multicentered, randomized trial, 172 comatose survivors of cardiac arrest were assigned to receive either stepped anti-seizure treatment that aimed to suppress rhythm and periodic EEG activity for 48 hours, or standard care which could include conventional sedative medications. Both groups received targeted temperature management.

The primary outcome was a poor neurologic outcome based on the cerebral performance category (CPC) with a poor outcome defined as severe disability, coma, or death. At three months. 90% of the patients in the anti-seizure treatment group and 92% of those in the control group had a poor neurologic outcome and the difference was not statistically significant. The secondary outcome of mortality at three months was high in both groups: 80% in the anti-seizure treatment group and 82% in the standard care group. However, the anti-seizure treatment group had a slightly longer intensive care stay and longer duration of mechanical ventilation. Mortality in the first 24 hours was higher in the control group. In both groups, over 80% of the patients had serious adverse events. The authors concluded that for comatose survivors of cardiac arrest, an intensive strategy of suppressing rhythmic and periodic EEG patterns with anti-seizure medication resulted in similar rates of poor outcomes compared to standard care.