Brain arrest neurological outcome scale (BrANOS): Predicting mortality and severe disability following cardiac arrest

Background: To create a predictive scale of neurological outcome following cardiac arrest (CA) that incorporates radiological and clinical markers of brain injury. Methods and results: Brain arrest neurologic outcome scale (BrANOS) is a prospective 16-point scale. It consisted of three variables: (1) duration of arrest (DAR), (2) reversed Glasgow coma scale (GCS), and (3) Hounsfield unit (HU) ratio on non-contrast CT scan of the head. Reversed GCS score was defined as 15-GCS (best GCS in the first 24 h). HU ratio was defined as the density ratio of the caudate nucleus over the posterior limb of the internal capsule measured on unenhanced CT scan of the brain. We identified 32 comatose patients who had: (1) CT scan performed within 48 h of event; (2) no previous history of either coma, severe head trauma, cardiac arrest or stroke. Primary outcome was defined as alive or dead. Secondary outcome was the Glasgow outcome score recorded on discharge. Patient demographics were collated from retrospective chart review. Patients' mean age was 63±3 years (mean±S.E.M.); 44% were females. Mortality rate was 81%. Mean DAR was 21±2 min. Survivors had a significantly lower BrANOS score (8±2 points) compared to non-survivors (13±1) (P=0.006). BrANOS was a strong predictor of mortality alone (ROC=0.86) and mortality with severe disability combined (ROC=0.9). The scale had a 100% specificity and positive predictive value. Conclusions: BrANOS is a reliable predictor of neurological outcome following CA. It is the first scale to incorporate clinical and radiological markers of brain injury.