Can survival from out-of-hospital cardiac arrest be predicted from a victim's carbon emissions?

摘要

It has been well established that prehospital resuscitation results in a fairly small proportion of viable survivors. Many of us hope that among current non-survivors there is yet another group of potentially salvageable patients for whom future resuscitative strategies will prove beneficial. However, given the frequent application of prehospital resuscitation to arrests that are neither sudden nor unexpected, such as those occurring in the setting of advanced age and terminal disease, along with those whose arrest was remote and unwitnessed, it seems inescapable that a large proportion of those in whom resuscitation is attempted have already crossed the River Styx. An interest in clinical markers of irreversible demise that would permit us to abort such predictably futile resuscitations (along with their not insignificant potential for downstream costs) and instead turn our focus to the comfort of the bereaved would be beneficial in populations where resuscitation is applied broadly to nearly any and all without a pulse.Omar Tuma and Mark Davies do an admirable job reviewing the state of the literature on end-tidal CO2 (ETCO2) as just such a marker of irreversible death in this issue of Resuscitation.1 The authors wisely eschew attempts at meta-analysis due to sizeable clinical heterogeneity between published reports. Their structured review reveals that, while ETCO2 as a sign of irreversible death is promising, the unknowns remain substantial.