Factors associated with cognitive recovery after cardiopulmonary resuscitation

A range of neuro-cognitive sequelae, from mild intellectual impairments to brain death, have been reported in survivors of aborted sudden cardiac death.

To determine to what extent, if any, factors associated with cardiopulmonary resuscitation, left ventricular function, and mood state are related to outcomes in five cognitive areas, namely orientation, attention, memory, reasoning, and motor performance.

Repeated measures were used to assess cognitive outcomes in 45 sudden cardiac arrest survivors over the 6 months following cardiopulmonary resuscitation. A battery of neuro-psychological tests was used to assess cognitive outcomes and psychological status over time. The relationship of the cardiopulmonary resuscitation, left ventricular function, and psychological variables to cognitive outcomes were assessed at each data point. The independent variables included time to cardiopulmonary resuscitation, time to defibrillation, duration of cardiopulmonary resuscitation, time to awakening, ejection fraction, New York Heart Association Class I to IV, tension, anger, and depression.

During hospitalization 38 of the 45 survivors (84%) had mild to severe deficits in one or more cognitive areas; 19 of 38 survivors (50%) continued to be impaired in one or more cognitive areas at 6 months. Of these, all had mild to severe deficits in at least one aspect of memory, with delayed recall the most frequent impairment. Time to awakening accounted for a unique portion of the variance in orientation and memory outcomes over time. The left ventricular function variables accounted for a significant portion of the variance in motor speed.

Our results suggest that half of the long-term survivors of aborted sudden cardiac death are cognitively intact 6 months after resuscitation but that 25% have moderate to severe impairment in memory, which could hamper and/or preclude the resumption of prearrest roles.