Head Computed Tomographic measurement as an early predictor of outcome in hypoxic-ischemic brain damage patients treated with hypothermia therapy

Hitoshi Yamamura, Shinichiro Kaga, Kazuhisa Kaneda, Tomonori Yamamoto, Yasumitsu Mizobata

BACKGROUND: Neurological abnormalities are a key factor in the prognosis of patients with post-cardiac arrest syndrome. In this study, we evaluated whether differences in CT measurements expressed in Hounsfield units (HUs) of the cerebral cortex and white matter can be used as early predictors of neurological outcome in patients treated with hypothermia therapy after hypoxic-ischemic brain damage. METHODS: We performed a retrospective study of 58 patients resuscitated after cardiac arrest between 2007 and 2010 who were treated with hypothermia therapy for the initial 24 hours post resuscitation. We divided the patients into 4 groups according to Glasgow Outcome Scale (GOS) score (GOS 1, GOS 2, GOS 3&4, and GOS 5) and assessed the correlations between GOS scores and HU differences between the cerebral cortex and white matter (DCW). RESULTS: The HU values of the cerebral cortex gradually decreased in accordance with worsening of neurological outcome. There were no significant intergroup differences in the HUs of the white matter among the groups. The DCW values were higher in patients with good neurological outcomes. The cut-off value for DCW indicative of poor neurological outcome was less than 5.5 in the GOS 1&2 groups, with a sensitivity of 63% and a specificity of 100%. CONCLUSIONS: This study showed that DCW values may be used for the prediction of neurological outcome of patients with post-cardiac arrest syndrome in the very early phase following the return of spontaneous circulation. Especially, a cut-off value for DCW of less than 5.5 may indicate poor neurological outcome.