Prognostication of patients after cardiopulmonary resuscitation

A recent study in England found that the Emergency Medical Services treat approximately 30 000 patients with an out-of-hospital cardiac arrest annually, with a crude survival rate to hospital discharge of 7.9%.(1) Other European countries report survival rates of up to 25%. The presenting rhythm and location of the arrest are significant and associated with different survival rates. The incidence of in-hospital cardiac arrest in the UK is 1.6 per 1000 hospital admissions. Overall survival to hospital discharge for this cohort is 18.4%; this is sub-divided to 49% and 11% for patients who present with shockable and non-shockable rhythms, respectively. 2 Survivors of cardiac arrest can make a full recovery without disability; however, many experience significant disability. The wide range of survival rates quoted in the literature is partly because of non-standardised definitions and data collection practices; therefore, many international statistics are not directly comparable with UK practice. The UK Resuscitation Council describe a chain of survival for patients who have had a cardiac arrest. 3 This chain starts with: (i) early recognition, (ii) early cardiopulmonary resuscitation, (iii) early defibrillation, and (iv) post-resuscitation care. There are ongoing national initiatives to strengthen each link, both in hospital and the community. This article focuses on the final link for patients who remain comatose after return of spontaneous circulation (ROSC) and require critical care management. These patients develop post-resuscitation syndrome, 4 a multiorgan phenomenon with four key components: (i) brain injury, (ii) myocardial dysfunction, (iii) systemic ischaemia and reperfusion response, and (iv) precipitating pathology. These components provide a useful conceptual framework for management and prognostication.