Rapid-response teams have been introduced to intervene in the care of patients with unexpected clinical deterioration. These teams are key components of rapid-response systems, which have been put in place because of evidence of “failure to rescue” with available clinical services, leading to serious adverse events. A serious adverse event may be defined as an unintended injury that is due in part to delayed or incorrect medical management and that exposes the patient to an increased risk of death and results in measurable disability. Rapidresponse systems aim to improve the safety of hospital-ward patients whose condition is deteriorating. These systems are based on identification of patients at risk, early notification of an identified set of responders, rapid intervention by the response team, and ongoing evaluation of the system’s performance and hospital-wide processes of care. Rapid-response systems have been implemented in many countries and across the United States.