Abstract
Background Despite advances in resuscitation medicine, the burden of in-hospital cardiac arrest (IHCA) remains substantial. The impact of these advances and changes in resuscitation guidelines on IHCA survival remains poorly defined. To better characterize evolving patient characteristics and temporal trends in the nature and outcomes of IHCA, we undertook a 20-year analysis of a national database. Methods and Results We analyzed the National Inpatient Sample (1999-2018) using International Classification of Diseases, Ninth Revision and Tenth Revision, Clinical Modification (ICD-9-CM and ICD-10-CM) codes to identify all adult patients suffering IHCA. Subgroup analysis was performed based on the type of cardiac arrest (ie, ventricular tachycardia/ventricular fibrillation or pulseless electrical activity-asystole). An age- and sex-adjusted model and a multivariable risk-adjusted model were used to adjust for potential confounders. Over the 20-year study period, a steady increase in rates of IHCA was observed, predominantly driven by pulseless electrical activity-asystole arrest. Overall, survival rates increased by over 10% after adjusting for risk factors. In recent years (2014-2018), a similar trend toward improved survival is noted, though this only achieved statistical significance in the pulseless electrical activity-asystole cohort. Conclusions Though the ideal quality metric in IHCA is meaningful neurological recovery, survival is the first step toward this. As overall IHCA rates rise, overall survival rates are improving in tandem. However, in more recent years, these improvements have plateaued, especially in the realm of ventricular tachycardia/ventricular fibrillation-related survival. Future work is needed to better identify characteristics of IHCA nonsurvivors to improve resource allocation and health care policy in this area.