In-hospital cardiac arrest: incidence, prognosis and possible measures to improve survival

Review.

Medical literature on in-hospital cardiac arrest (IHCA) was reviewed to summarise: (a) the incidence of and survival after IHCA, (b) major prognostic factors, (c) possible interventions to improve survival.

The incidence of IHCA is rarely reported in the literature. Values range between 1 and 5 events per 1,000 hospital admissions, or 0.175 events/bed annually. Reported survival to hospital discharge varies from 0% to 42%, the most common range being between 15% and 20%. Pre-arrest prognostic factors: the prognostic value of age is controversial. Among comorbidities, sepsis, cancer, renal failure and homebound lifestyle are significantly associated with poor survival. However, pre-arrest morbidity scores have not yet been prospectively validated as instruments to predict failure to survive after IHCA. Intra-arrest factors: ventricular fibrillation/ventricular tachycardia (VF/VT) as the first recorded rhythm and a shorter interval between IHCA and cardiopulmonary resuscitation or defibrillation are associated with higher survival. However, VF/VT is present in only 25-35% of IHCAs. Short-term survival is also higher in patients resuscitated with chest compression rates above 80/min. Interventions likely to improve survival include: early recognition and stabilisation of patients at risk of IHCA to enable prevention, faster and better in-hospital resuscitation and early defibrillation. Mild therapeutic hypothermia is effective as post-arrest treatment of out-of-hospital cardiac arrest due to VF/VT, but its benefit after IHCA and after cardiac arrest with non-VF/VT rhythms has not been clearly demonstrated.