Cardiac arrest and disorders of consciousness

As the second most common cause of coma and disorders of consciousness, cardiac arrest is defined as a cessation of cardiac mechanical activity and absence of circulation. Cardiac arrest can happen due to an intrinsic cardiac condition or secondary to noncardiac causes such as respiratory, neurologic, metabolic causes or external causes such as toxic ingestion, asphyxia, drowning, trauma, and other environmental exposures. While cardiac arrest resuscitation research and practice has evolved over decades, the overall survival to hospital discharge remains low across different types of cardiac arrest (about 9%-29%). This chapter focuses on disorders of consciousness after cardiac arrest and how it is different from other etiologies. It also discusses advances and controversies in diagnosis, management, prognostication and research.