Loss of gray–white matter discrimination as an early CT sign of brain ischemia/hypoxia in victims of asphyxial cardiac arrest

Abstract

Brain CT obtained from cardiac arrest (CA) victims immediately after resuscitation may be useful in predicting their outcomes. Most data have been derived from CA victims of cardiac etiology, however, CT signs of brain ischemia/hypoxia have rarely been studied in victims of asphyxial CA. Loss of gray–white matter discrimination (GWMD) at the basal ganglia seems to be the most reliable early CT sign of brain ischemia/hypoxia; a retrospective study was conducted to clarify its incidence, prognostic significance, and temporal profile in resuscitated victims of CA by food asphyxiation. Brain CT scans of each victim were interpreted by two blinded observers. During a 5-year period, 39 resuscitated victims of CA by food asphyxiation underwent brain CT. Thirty-one (79%) showed loss of GWMD, none of whom survived to discharge. Among the other eight victims with seemingly intact brain CT, five (63%) survived to discharge. Loss of GWMD predicted fatality with sensitivity of 100% and specificity of 63%. The interobserver concordance was 82% with kappa coefficient of 0.56. Loss of GWMD developed almost invariably when the asphyxiation–return of spontaneous circulation (ROSC) interval exceeded 10 min. There were five victims with asphyxiation–ROSC interval ≤ 10 min, all of whom survived to discharge. In contrast, none of the 34 victims with the interval >10 min survived to discharge. Loss of GWMD may develop in a relatively time-dependent manner and may be a reliable radiographic indicator of poor outcome in resuscitated victims of asphyxial CA.