Delayed awakening after targeted temperature management (TTM) and sedation is frequent among cardiac arrest patients. Differentiating between prolonged coma and irreversible cerebral damage can be challenging, therefore the utilization of a multimodal approach is recommended by international guidelines. Here, we discuss indications and advantages/disadvantages of available modalities for coma prognostication and describe new tools to improve our accuracy for outcome prediction.
Studies from the TTM era confirmed that combining neurological examination with electrophysiological assessment [electroencephalography (EEG) and somato-sensory evoked potentials (SSEP)] greatly improves coma prognostication. This combination is nowadays recognized as the most useful by many clinicians and appears widely applicable as part of initial patient assessment. Additional tests (serum neuron specific enolase and neuroimaging) may be most useful to orient clinical decisions in patients with prolonged coma. Advanced analysis of EEG and SSEP recordings and the emergence of quantitative pupillometry hold great promise.
Multimodal prognostication offers a comprehensive approach of anoxic-ischemic encephalopathy and is increasingly used in postresuscitation care. Worldwide implementation and future advancements of available modalities, together with the increasing use of novel automated devices for quantitative neurological examination, may further optimize prognostic accuracy in the early ICU phase following cardiac arrest.