Afferent Limb of Rapid Response System Activation

  • J. Moore
  • M. Hravnak
  • M. R. Pinsky
Part of the Annual Update in Intensive Care and Emergency Medicine book series (AUICEM, volume 2012)


Fundamental to the implementation of a functional rapid response system for the treatment of hospitalized patients is the identification of instability by the bedside caregivers who must activate the alert. This afferent limb of the rapid response system has the primary goal of crisis detection and is, therefore, the essential first element of effective rapid response system operations. More specifically, its purpose is the early recognition of ‘emergent unmet patient needs’, defined as mismatches between the care a patient is receiving and the care that patient immediately requires [1]. The afferent limb has the unique challenge of moving from its inception point, characterized by the clinical surveillance of all hospital inpatients during their admission, to its distinct endpoint of efferent limb activation of a rescue response for specific patients at specific times during their hospital stay. It may even be speculated that the inability for any trial to demonstrate that the application of a rapid response system definitively decreases mortality [2] may lie with failures to adequately monitor patients for instability, recognize instability once it occurs, and decide to make the call to escalate care — all components of the rapid response system afferent arm. In order to meet this challenge to safely and effectively rescue unstable patients, those wishing to design and maintain a timely, effective and efficient afferent limb of a rapid response system must address three components.


False Alarm Medical Emergency Team Afferent Limb Rapid Response System Efferent Limb 
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  1. 1.
    Devita MA, Bellomo R, Hillman K, et al (2006) Findings of the First Consensus Conference on Medical Emergency Teams. Crit Care Med 34: 2463–2478PubMedCrossRefGoogle Scholar
  2. 2.
    Jones DA, DeVita MA, Bellomo R (2011) Rapid-response teams. N Engl J Med 365: 139–146PubMedCrossRefGoogle Scholar
  3. 3.
    Hillman K, Parr M, Flabouris A, Bishop G, Stewart A (2001) Redefining in-hospital resuscitation: The concept of the medical emergency team. Resuscitation 48: 105–110PubMedCrossRefGoogle Scholar
  4. 4.
    Smith GB, Prytherch DR, Schmidt PE, Featherstone PI, Higgins B. (2008) A review and performance evaluation of single-parameter “track-and-trigger” systems. Resuscitation 79: 11–21PubMedCrossRefGoogle Scholar
  5. 5.
    Subbe CP, Kruger M Rutherford P, Gemmel L (2001) Validation of a modified early warning score in medical admissions. Q J Med 2001 94: 521–526CrossRefGoogle Scholar
  6. 6.
    Ludikhuize J, DeJonge E, Goosens A (2011) Measuring adherence among nurses one year after training in applying the Modified Early Warning Score and Situation-Background-Assessment-Recommendation instruments. Resuscitation 82: 1428–1433PubMedCrossRefGoogle Scholar
  7. 7.
    Gao H, McDonnell A, Harrison DA, et al (2007) Systematic review and evaluation of track and trigger warning systems for identifying at-risk patients in the ward. Intensive Care Med 33: 667–679PubMedCrossRefGoogle Scholar
  8. 8.
    Cuthbertson BH, Boroujerdi M, McKie L, Aucott L, Prescott G (2007) Can physiological variables and early warning scoring systems allow early detection of the deteriorating surgical patient? Crit Care Med 35: 402–409PubMedCrossRefGoogle Scholar
  9. 9.
    Cuthbertson BH, Smith GB (2007) A warning on early-warning scores! Br J Anaesth 98: 704–706PubMedCrossRefGoogle Scholar
  10. 10.
    Tarrassenko L, Clifton DA, Pinsky M, Hravnak M, Woods JR, Watkinson PJ (2011) Centile-based early warning scores derived from statistical distributions of vital signs. Resuscitation 82: 1013–1018CrossRefGoogle Scholar
  11. 11.
    Smith GB, Prytherch DR, Schmidt PE, et al (2008) Should age be included as a component of track and trigger systems used to identify sick adult patients? Resuscitation 78: 109–115PubMedCrossRefGoogle Scholar
  12. 12.
    Yousef K, Pinsky MR, DeVita MA, Sereika S, Hravnak M (2011) Demographic and clinical predictors of cardiorespiratory instability in a step-down unit: pilot study. Am J Crit Care (in press)Google Scholar
  13. 13.
    Borowski M, Görges M, Fried R, Such O, Wrede C, Imhoff M (2011) Medical device alarms. Biomed Tech (Berl) 56: 73–83CrossRefGoogle Scholar
  14. 14.
    Graham KC, Cvach M (2010) Monitor alarm fatigue: standardizing use of physiological monitors and decreasing nuisance alarms. Am J Crit Care 19: 28–34PubMedCrossRefGoogle Scholar
  15. 15.
    Hravnak M, Edwards L, Clontz A, Valenta C, Devita MA, Pinsky MR (2008) Defining the incidence of cardiorespiratory instability in patients in step-down units using an electronic integrated monitoring system. Arch Intern Med 168: 1300–1308PubMedCrossRefGoogle Scholar
  16. 16.
    Tarassenko L, Hann A, Young D (2006) Integrated Monitoring and Analysis for Early Warning of Patient Deterioration. Br J Anaesth 97: 64–68PubMedCrossRefGoogle Scholar
  17. 17.
    Hravnak M, DeVita MA, Clontz A, Edwards L, Valenta C, Pinsky MR (2011) Cardiorespiratory instability before and after implementing an integrated monitoring system. Crit Care Med 39: 65–72PubMedCrossRefGoogle Scholar
  18. 18.
    Task Force of the American College of Critical Care Medicine and the Society of Critical Care Medicine (1999) Guidelines for intensive care unit admission, discharge, and triage. Crit Care Med 27: 633–638CrossRefGoogle Scholar
  19. 19.
    Hillman K, Chen J, Cretikos M, et al (2005) Introduction of the Medical Emergency Team (MET) system: A cluster-randomized controlled trial. Lancet 365: 2091–2097PubMedCrossRefGoogle Scholar

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© Springer-Verlag Berlin Heidelberg 2012

Authors and Affiliations

  • J. Moore
  • M. Hravnak
  • M. R. Pinsky

There are no affiliations available

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