Rapid response system

A rapid response system (RRS) is a system implemented in many hospitals designed to identify and respond to patients with early signs of clinical deterioration on non-intensive care units with the goal of preventing respiratory or cardiac arrest.^[1] A rapid response system consists of two clinical components, an afferent component, an efferent component, and two organizational components – process improvement and administrative.^[2]

The afferent component consists of identifying the input

The afferent component, or identification limb, also known as the track-and-trigger system, uses standardized tools to track early signs of reversible clinical deterioration and trigger a call to, and response from the efferent component, or response limb.

The process improvement component uses evidence-based evaluation of the RRS to determine its effectiveness and to improve the system through targeted interventions. It works closely with the administrative component, clinicians (especially those on RRTs), and quality improvement experts to evaluate three measures: outcomes measures, process measures, and balancing measures.[9]

Outcomes measures

Rates of hospital-wide mortality and respiratory and cardiac arrest, which are exceedingly rare and may or may not be preventable, are common outcome measures.^[10] Rapid response teams appear to decrease the rates of respiratory and cardiac arrest outside the intensive care unit.^{[11][12][13][14]} They also appear to decrease the chance of death in hospital.^[11] Overall effectiveness of rapid response teams is somewhat controversial due to the variability across studies^[12][15][16] as is the overall effectiveness of the rapid response system in improving patient safety.^[10][17] More recent work uses proximal outcome measures, such as the Children’s Resuscitation Intensity Scale (measures level of care within 12 hours pre-transfer),^[18] the Clinical Deterioration Metric (measures level of care within 12 hours post-transfer),^[19] and UNSAFE transfers (measures level of care within 1 hour post-transfer).^[20]

Process measures

Process measures determine if the RRS is used as intended. Measures include the MET call rate, percentage of MET calls that result in transfer to the ICU, the time between initial physiologic abnormality and admission to ICU, timing of calls, reasons for MET calls, and evaluation of early warning scores using sensitivity and specificity.^[21][22][23]

Balancing measures

Balancing measures evaluate any unintended consequences of the RRS. Identified barriers to activating the MET include the primary team’s overconfidence in their ability to stabilize the patient, poor communication, hierarchal problems, and hospital culture.^[24][25][26] Interventions to overcome barriers include improved intradisciplinary staff education, protocol requiring activation when calling criteria are met, and use of “champions” to foster cultural change.^[27][28]

Administrative component

The administrative component oversees the planning, implementation, and maintenance phases for the RRS. A formal committee of frontline clinicians and ward and ICU leaders operate the administrative component.

METs were originally activated exclusively by bedside clinicians in need of emergency assistance. Recently, many hospitals have begun to allow families to activate a MET if they feel the care team is not adequately addressing their concerns. The team may differ in composition from the clinician-activated MET such as including a patient relations coordinator.[29]

Family-activated METs were put in place as a response to the preventable death of Josie King in 2001. King was 18-months old when she died at