Introduction

In the United Kingdom, out-of-hospital cardiac arrests (OHCA) reported to ambulance services amount to over 110,000 per year, with resuscitation attempted in around 45,000 cases, and in-hospital cardiac arrests (IHCA) around 12,000 annually. [1] This is associated with high mortality, but a considerable proportion of those who survive the event have a poor neurological recovery.

Overall, 30-day survival for OHCA in England remains low at 9.5%. Results are slightly better for IHCA with 25.8% surviving to discharge, or up to 52.9% if the initial rhythm is ventricular fibrillation (VF) or ventricular tachycardia (VT). [2]

Despite advances in post-resuscitation care management, about 50% of resuscitated patients from cardiac arrests (CA) die or have a poor neurological prognosis. One of the major causes of mortality following CA is severe neurological damage due to post-anoxic brain injury. [2]

The associated costs and length of stay is also significantly higher in patients with poor neurological outcome. [3] There are further considerations like community care and rehabilitation, quality of life and emotional impact on the family.

It is therefore essential to predict neurological outcome in this group of patients as early as possible, to potentially enable early withdrawal of life-saving treatment (WLST) in those patients predicted to have a poor outcome. [4]