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Copyright: © Singapore Medical Association
We want our patients to get well and return to their pre-illness lives. However, the grim reality is that 3%–9% of patients in hospital experience clinical deterioration during their stay. A transition from one clinical state to one that is worse increases their risk of morbidity or death.(1)
Survival rates after hospital cardiac arrests are poor, with a one-year survival of about 13.4% according to Schluep et al.(2) However, up to 80% of cardiopulmonary arrests are preceded by periods of physiological instability.(3-5) When recognised and acted on appropriately, such antecedent events are windows of opportunity whereby timeous and appropriate interventions, perhaps in the form of a rapid response system (RRS) crisis call, could alter the trajectory and spiral of deterioration. RRS functions through an afferent, ‘crisis detection’ and ‘response triggering’ mechanism that actuates its purposes through an efferent, prearranged rapid response team (RRT). The system is complemented and supported by a governance/administrative structure that organises and supplies resources, and also has audit and evaluating functions.(6) This concept was first introduced at the first International Conference on Medical Emergency Teams in 2005.
In the event of a crisis call, multidisciplinary teams or RRTs, which usually comprise a group of clinicians (i.e. physicians, nurses and respiratory therapists), attend to such crisis events to support frontline healthcare staff in the management of these acutely deteriorating patients.(7) Two recent meta-analyses have highlighted the statistically significant reduction of in-hospital cardiac arrests and hospital mortality after the implementation of RRS.(8,9) The use of scarce intensive care unit (ICU) resources can be suitably triaged and appropriately deployed,(10) resulting in reduced incidences of postoperative adverse outcomes/mortality, as well as reducing the mean duration of hospital stays.(11)
The effectiveness of RRS in reducing hospital mortality is supported by an early landmark randomised controlled trial conducted by Priestley et al in 2004.(12) Over the years, various studies also provided sound evidence of clinical outcome improvement after the implementation of RRS.(13,14) However, some studies proved otherwise.(15,16) In particular, two major randomised trials involving RRS – the MERIT (Medical Early Response, Intervention and Therapy) trial(17) and the EPOCH trial on the effect of a paediatric early warning system on all-cause mortality in hospitalised paediatric patients(18) (with important limitations) – failed to demonstrate benefits based on the endpoints of death, unexpected cardiac arrests and unplanned ICU admissions.
Variations in the efferent or action/response limb of the RRS also affect its effectiveness. Further research is required to identify the configuration and composition of RRS team members that give the best fit and which trigger system(19) is most appropriate. Aggregate-weighted multi-component early warning scores such as the Modified Early Warning Score, a simple physiological scoring tool that aids communication between nursing and medical staff about deteriorating patient conditions, are used by the early response team in decision-making. Although helpful in identifying early deterioration, the Modified Early Warning Score has been shown to have limitations in discriminatory performance and generalisability.(20) It was also noted to have lower sensitivity and specificity in certain populations.(21)
One of the most widely used outcomes in assessing the clinical effects of an RRS is the volume of unplanned ICU admissions from general wards. A decrease in unplanned ICU admissions reflects recognition and early treatment of at-risk patients in general wards. Studies, including the COMET pragmatic study,(22,23) demonstrated a significant reduction in unplanned ICU admissions after the introduction of an RRS. While a Dutch study(24) reported an increase in unplanned ICU admissions, Sakai and Devita(7) refuted this concern, opining that an increased number of admissions to the ICU does not necessarily translate to an increase in ICU days. On the contrary, earlier detection and prompt treatment of critically ill patients may reduce the number of days that each patient spends in the ICU.
While the RRS is designed to recognise and respond to clinically deteriorating patients, overly sensitive criteria for activating the RRS may result in excessive activation of the team, causing system fatigue with questionable tangible benefits.(8) Conversely, non-activation and delays in activation may cause harm.(25) Cultural barriers in the clinical environment,(7) unclear roles between the primary and response team,(26) and a lack of standardisation of trigger thresholds for activation(26) have contributed to under-utilisation of the RRS. DeVita et al(27) and Foraida et al(28) have argued that this problem may be ameliorated by having clearly defined and objective criteria for initiating a crisis activation, as well as disseminating and publicising these among healthcare staff. Alternatively, having mandatory activation of RRS when criteria are met, rather than voluntary activation, has been described.(29) Importantly, when there is a delay in activating appropriate crisis calls, feedback must be given to those involved, in the spirit of education and quality assurance.
Some have advocated for patient- and family-initiated escalation schemes. These can arguably act as a safety mechanism through better and quicker identification of patient deterioration.(30) However, differing cultures and contexts may affect its transferability and therefore, widespread adoption.
Another concern faced in the implementation of RRS, according to a study by Liaw et al, is reliance on the RRT, which can potentially lead to deskilling of ward staff in acute care and treating medical crises.(26) In practice, RRS members would expect the participation of the ward staff when they respond to activations. This presents opportunities for point-of-care teaching and has resulted in improved confidence in managing decompensating patients.(31) Moreover, staff are expected to maintain competency in managing acute deterioration, even with the availability of RRS. This is not unlike the expectation and requirement that all hospital staff demonstrate competency and maintain expertise in Basic and Advanced Cardiac Life Support through regular refresher courses, for the occasion, however rare, when these skills are needed.
Regardless of the arguments and verdict, the value RRS adds to patient well-being has received objective affirmation and vindication, with the United States’ Institute for Healthcare Improvement advocating for its deployment.(32) Moreover, the Joint Commission(33) and the American Heart Association(34) have mandated and recommended the use of RRS in American hospitals and general care wards, respectively.
RAPID RESPONSE SYSTEMS IN SINGAPORE
There was little information regarding RRS in Singapore before Liaw et al’s study,(26) which cleverly used an instrumental case study approach(35) in their exploration of RRS in local acute public sector hospitals. By using a mixed methodology and employing a structured interview, the authors provided thick descriptors to portray the complexities of their study topic. This attempt at a national study allowed comparison across the participating hospitals. Significantly, the study demonstrated a lack of uniformity with regard to how these hospitals deployed RRS and its variants in moments of need. This reflected the absence of a local ‘best fit’ system appropriate to the local context, thereby indicating the need for national standardisation to streamline and improve the performance of the RRS. One could perhaps start by unifying the various track and trigger systems currently in use (single- or multiple-parameter systems, aggregate scores or combined system). What could be even more helpful is triangulating their findings with opinions from RRS ‘users and doers’ for a thorough, interpretivist real-world view of this topic.
Finally, in the spirit of action research,(36) Liaw et al(26) could work with the recently formed RRS chapter of the Society of Intensive Care Medicine (Singapore)(37) as well as other bodies such as the Ministry of Health and local universities(38) to advocate for a national standardised RRS model that is fit for purpose, so that it can become an integral part of the acute care ecosystem.
1. Jones D, Mitchell I, Hillman K, Story D. Defining clinical deterioration. Resuscitation 2013; 84:1029-34.
2. Schluep M, Gravesteijn BY, Stolker RJ, Endeman H, Hoeks SE. One-year survival after in-hospital cardiac arrest: a systematic review and meta-analysis. Resuscitation 2018; 132:90-100.
3. Le Conte P, Baron D, Trewick D, et al. Withholding and withdrawing life-support therapy in an emergency department: prospective survey. Intensive Care Med 2004; 30:2216-21.
4. Nurmi J, Harjola VP, Nolan J, Castrén M. Observations and warning signs prior to cardiac arrest. Should a medical emergency team intervene earlier? Acta Anaesthesiol Scand 2005; 49:702-6.
5. Andersen LW, Kim WY, Chase M, et al. The prevalence and significance of abnormal vital signs prior to in-hospital cardiac arrest. Resuscitation 2016; 98:112-7.
6. Devita MA, Bellomo R, Hillman K, et al. Findings of the first consensus conference on medical emergency teams. Crit Care Med 2006; 34:2463-78.
7. Sakai T, Devita MA. Rapid response system. J Anesth 2009; 23:403-8.
8. Maharaj R, Raffaele I, Wendon J. Rapid response systems: a systematic review and meta-analysis. Crit Care 2015; 19:254.
9. Solomon RS, Corwin GS, Barclay DC, Quddusi SF, Dannenberg MD. Effectiveness of rapid response teams on rates of in-hospital cardiopulmonary arrest and mortality: a systematic review and meta-analysis. J Hosp Med 2016; 11:438-45.
10. Jones DA, DeVita MA, Bellomo R. Rapid-response teams. N Engl J Med 2011; 365:139-46.
11. Bellomo R, Goldsmith D, Uchino S, et al. Prospective controlled trial of effect of medical emergency team on postoperative morbidity and mortality rates. Crit Care Med 2004; 32:916-21.
12. Priestley G, Watson W, Rashidian A, et al. Introducing Critical Care Outreach: a ward-randomised trial of phased introduction in a general hospital. Intensive Care Med 2004; 30:1398-404.
13. Oh TK, Kim S, Lee DS, et al. A rapid response system reduces the incidence of in-hospital postoperative cardiopulmonary arrest: a retrospective study. Can J Anaesth 2018; 65:1303-13.
14. Bellomo R, Goldsmith D, Uchino S, et al. A prospective before-and-after trial of a medical emergency team. Med J Aust 2003; 179:283-7.
15. Jung B, Daurat A, De Jong A, et al. Rapid response team and hospital mortality in hospitalized patients. Intensive Care Med 2016; 42:494-504.
16. Chan PS, Khalid A, Longmore LS, et al. Hospital-wide code rates and mortality before and after implementation of a rapid response team. JAMA 2008; 300:2506-13.
17. Cretikos MA, Chen J, Hillman KM, et al. The effectiveness of implementation of the medical emergency team (MET) system and factors associated with use during the MERIT study. Crit Care Resusc 2007; 9:205-12.
18. Parshuram CS, Dryden-Palmer K, Farrell C, et al. Effect of a pediatric early warning system on all-cause mortality in hospitalized pediatric patients: the EPOCH randomized clinical trial. JAMA 2018; 319:1002-12.
19. Sørensen EM, Petersen JA. Performance of the efferent limb of a rapid response system: an observational study of medical emergency team calls. Scand J Trauma Resusc Emerg Med 2015; 23:69.
20. Smith GB, Prytherch DR, Meredith P, Schmidt PE, Featherstone PI. The ability of the National Early Warning Score (NEWS) to discriminate patients at risk of early cardiac arrest, unanticipated intensive care unit admission, and death. Resuscitation 2013; 84:465-70.
21. Ho LO, Li H, Shahidah N, et al. Poor performance of the modified early warning score for predicting mortality in critically ill patients presenting to an emergency department. World J Emerg Med 2013; 4:273-8.
22. Ludikhuize J, Brunsveld-Reinders AH, Dijkgraaf MGW, et al. Outcomes associated with the nationwide introduction of rapid response systems in the Netherlands. Crit Care Med 2015; 43:2544-51.
23. Kurita T, Nakada TA, Kawaguchi R, et al. Impact of increased calls to rapid response systems on unplanned ICU admissions. Am J Emerg Med 2020; 38:1327-31.
24. Simmes FM, Schoonhoven L, Mintjes J, Fikkers BG, van der Hoeven JG. Incidence of cardiac arrests and unexpected deaths in surgical patients before and after implementation of a rapid response system. Ann Intensive Care 2012; 2:20.
25. Downey AW, Quach JL, Haase M, et al. Characteristics and outcomes of patients receiving a medical emergency team review for acute change in conscious state or arrhythmias. Crit Care Med 2008; 36:477-81.
26. Liaw SY, Tee A, Carpio GAC, Ang SBL, Chua WL. Review of systems for recognising and responding to clinical deterioration in Singapore hospitals: a nationwide cross-sectional study. Singapore Med J 2020; 61:184-9.
27. DeVita MA, Braithwaite RS, Mahidhara R; Medical Emergency Response Improvement Team (MERIT). Use of medical emergency team responses to reduce hospital cardiopulmonary arrests. Qual Saf Health Care 2004; 13:251-4.
28. Foraida MI, DeVita MA, Braithwaite RS, et al. Improving the utilization of medical crisis teams (Condition C) at an urban tertiary care hospital. J Crit Care 2003; 18:87-94.
29. Jones CM, Bleyer AJ, Petree B. Evolution of a rapid response system from voluntary to mandatory activation. Jt Comm J Qual Patient Saf 2010; 36:266-70, 241.
30. McKinney A, Fitzsimons D, Blackwood B, McGaughey J. Patient and family-initiated escalation of care: a qualitative systematic review protocol. Syst Rev 2019; 8:91.
31. Haegdorens F, Van Bogaert P, Roelant E, et al. The introduction of a rapid response system in acute hospitals: a pragmatic stepped wedge cluster randomised controlled trial. Resuscitation 2018; 129:127-34.
32. Berwick DM, Calkins DR, McCannon CJ, Hackbarth AD. The 100,000 lives campaign: setting a goal and a deadline for improving health care quality. JAMA 2006; 295:324-7.
33. Revere A, Eldridge N. Joint Commission National Patient Safety Goals for 2008. Top Patient Saf 2008; 12:1-4.
34. Kronick SL, Kurz MC, Lin S, et al. Part 4: systems of care and continuous quality improvement: 2015 American Heart Association guidelines update for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation 2015; 132(18 Suppl 2):S397-413.
35. Stake RE. The Art of Case Study Research. SAGE, 1995: 49-68.
36. Rowell LL, Polush EY, Riel MM, Bruewer A. Action researchers' perspectives about the distinguishing characteristics of action research: a Delphi and learning circles mixed-methods study. Educ Action Res 2015; 23:243-70.
37. Rapid Response System Chapter (RSS-SICM). In: Society of Intensive Care Medicine, Singapore [online]. Available at: https://sicm.org.sg/article/64sVl. Accessed November 23, 2019.
38. Programme in Health Services and System Research (HSSR). In: Duke-NUS Medical School, Singapore [online]. Available at: https://www.duke-nus.edu.sg/hssr. Accessed November 23, 2019.