Background
Rapid response teams represent an intuitively simple concept: When a patient demonstrates signs of imminent clinical deterioration, a team of providers is summoned to the bedside to immediately assess and treat the patient with the goal of preventing intensive care unit transfer, cardiac arrest, or death. Such teams have become a widely used patient safety intervention due in large part to their inclusion in the Institute for Healthcare Improvement's "100,000 Lives Campaign" in 2005. However, the rapid response team concept has come to exemplify the tension between those arguing for swift implementation of conceptually attractive patient safety interventions supported by anecdotal evidence of benefit and those advocating a more rigorous, evidence-based—and inevitably slower—approach.
Patients whose condition deteriorates acutely while hospitalized often exhibit warning signs (such as abnormal vital signs) in the hours before experiencing adverse clinical outcomes. In contrast to standard cardiac arrest or "code blue" teams, which are summoned only after cardiopulmonary arrest occurs, rapid response teams are designed to intervene during this critical period, usually on patients on general medical or surgical wards.
Several different models of rapid response teams exist (see Table 1), and a 2006 consensus conference advocated use of the term "rapid response system" (RRS) as a unifying term. Hospitalists are increasingly assuming RRS duties, either as the primary responder or to assist nurse-led teams.
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Table 1. Rapid Response System Models
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Model
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Personnel
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Duties
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Medical Emergency Team
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Physicians (critical care or hospitalist) and nurses
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Critical Care Outreach
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Critical care physicians and nurses
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- Respond to emergencies
- Follow up on patients discharged from ICU
- Proactively evaluate high-risk ward patients
- Educate ward staff
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Rapid Response Team
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Critical care nurse, respiratory therapist, and physician (critical care or hospitalist) backup
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- Respond to emergencies
- Follow up on patients discharged from ICU
- Proactively evaluate high-risk ward patients
- Educate and act as liaison to ward staff
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A useful construct is to consider RRSs as having "afferent" (the criteria for calling) and "efferent" (responsive) arms. Despite differences in team structure, the criteria used to summon the teams are generally similar. Bedside staff are encouraged to call the team when any of a number of prespecified criteria (Table 2) are met. At certain hospitals, patients and family members are also permitted to call the team. Recent research has focused on development of more sophisticated "track-and-trigger" bedside monitoring systems that could be used to automatically trigger intervention when certain physiologic abnormalities are detected.
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Table 2. Typical Rapid Response System Calling Criteria
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Any staff member may call the team if one of the following criteria is met:
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o Heart rate over 140/min or less than 40/min
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o Respiratory rate over 28/min or less than 8/min
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o Systolic blood pressure greater than 180 mmHg or less than 90 mmHg
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o Oxygen saturation less than 90% despite supplementation
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o Acute change in mental status
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o Urine output less than 50 cc over 4 hours
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o Staff member has significant concern about the patient's condition
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Additional criteria used at some institutions:
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o Chest pain unrelieved by nitroglycerin
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o Threatened airway
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o Seizure
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o Uncontrolled pain
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Evidence of Effectiveness
Early publications on RRSs reported significant improvements in clinical outcomes, but the only randomized trial to date did not demonstrate improvement in any patient outcome. Multiple reviews also found no consistent evidence that RRSs benefited patients. As well, no comparative data exist to support one RRS model over another, nor are there data on the cost-effectiveness of RRS. The RRS concept has thus become an example of "the tension between needing to improve care and knowing how to do it." Proponents argue that the face validity and potential benefit of RRS justify immediate implementation, while others advocate for further research to define optimal team structure and patient populations most likely to benefit before mandating RRS implementation.
Current Context
The strong endorsement of RRSs by the Institute for Healthcare Improvement, coupled with the 2008 Joint Commission National Patient Safety Goal—which does not mandate RRS per se but does require hospitals to implement systems to enable "healthcare staff members to directly request additional assistance from a specially trained individual(s) when the patient's condition appears to be worsening"—have led to widespread implementation of RRS. Recent methodologically stronger before-and-after studies are beginning to present a stronger, evidence-based case for benefit. Finally, the teams have proven to be a very popular intervention among nursing staff and can be useful for identifying systematic problems in care, factors which themselves may justify the development of RRS. Based on all these forces, nearly half of the 6000 hospitals in the United States have implemented some form of RRS (as of 2006).