Critical Care Research and Practice / 2019 / Article / Tab 3

Review Article

Performance of the Afferent Limb of Rapid Response Systems in Managing Deteriorating Patients: A Systematic Review

Table 3

Summary of relevant studies on escalating care to deteriorating patients.

Outcome measures

Jones et al. [50]
To assess the attitudes of nurses to the MET system 4 years after its introduction and obstacles to its use
Prospective observational survey in one university hospital
351 ward nurses
Barriers to calling the MET
Nurses’ attitudes toward the MET system
(i) Major barriers to MET activation were the traditional model of calling a junior doctor before the MET (72%) and underestimation of physiological perturbations associated with the presence of MET call criteria
(ii) Nurses would make a MET call for a patient they were worried even if the vital signs were normal (56%)

Schmid-Mazzoccoli et al. [51]
To identify nurse, patient, and organizational variables that predict delayed MET calls
Prospective observational study in one university hospital
Convenience sample of 108 MET interventions on medical and surgical general wards
Delayed MET calls: MET criteria present for >30 min before the call
(i) Delayed events were 44% (47/108) often on the night shift ()
(ii) The shift and patient-unit-match (medical, surgical) were significant predictors of delays
(iii) Patient, nurse, and organizational characteristics influenced the timely rescue

Bagshaw et al. [52]
To evaluate the vision of nurses on the MET system 3 years after its implementation
Cross-sectional survey in one academic hospital
275 ward nurses
Beliefs and behaviors of nurses regarding the MET system
(i) Nurses would call the attending physician before activating the MET (75.9%), they would activate the MET for a patient they were worried even if the patient had normal vital signs (48%), and they were reluctant to activate the MET for the fear of criticism (15.4%)

Calzavacca et al. [53]
To test the impact of RRS maturation on delayed MET activation (MET criterion documented at least 1 h before MET activation) and patient outcomes
Before-and-after observational study in one tertiary hospital
MET reviews in a recent cohort (200 patients) and in a control cohort (400 patients) 5 years earlier of RRS implementation
ICU admission, hospital LOS, and hospital mortality after MET reviews
(i) Fewer patients (22% vs. 40.3%, ) had delayed MET activation in a recent cohort vs. a control cohort
(ii) Delayed activation was associated with greater risk of unplanned ICU admission and hospital mortality (OR 1.79, 95% CI 1.33–2.93, and OR 2.18, 95% CI 1.42–3.33, , respectively)

Trinkle and Flabouris [54]
To measure and describe ALF and its impact on patient outcomes
Retrospective observational study in one university-affiliated hospital
443 patients and 575 adverse events (6.1% (35/575) cardiac arrests, 68.7% (395/575) MET calls, and 25.2% (145/575) unanticipated ICU admissions)
ALF as the RRS performance and the impact on patient outcomes
(i) Documented ALF was described in 22.8% (131/575) of adverse events
(ii) Patients with ALF vs. those without ALF had more unanticipated ICU admissions, 34.4% (45/131) vs. 22.5% (100/444), () and higher hospital mortality across multiple, compared to single, time periods, 52.5% (21/40) vs. 31.9% (22/69), ()

Shearer et al. [55]
To explore the causes of the failure of RRS activation in the acute adult population
Multimethod study: the missed RRS incidence, the prospective study of missed RRS calls, and staff interviews in four university tertiary hospitals
570 adult observation charts, 91 staff interviews (physicians, nurses, MET members, ICU teams) involved in missed RRS calls
Physiological instability and outcomes of ward patients
Missed RRS calls
Staff interviews
(i) 4.04% (23/570) of patients had a clinical instability, 42% of them did not receive an appropriate clinical response, although the staff recognized criteria for RRS activation (69.2%), and being “quite” or “very” concerned about their patient (75.8%)
(ii) Missed RRS calls were 43.47% (10/23), the main reason was to feel that the situation was under control in the ward (51.8%)
(iii) The failure to RRS activation was due to dominantly sociocultural reasons

Boniatti et al. [56]
To evaluate an association between delayed MET calls and mortality
Prospective observational study in one university-affiliated tertiary hospital
1,481 calls for 1,148 patients
Delayed MET calls (namely documented MET criteria with no MET calls for 30 min to 24 h before a MET review) and mortality
(i) Delayed MET calls resulted in 21.4% (246/1,148) of patients, significantly higher for physicians (110/377, 29.2%) vs. nurses (136/771, 17.6%),
(ii) 30-day mortality after the MET review was higher for patients with delayed vs. timely MET activation, 61.8% (152/246) vs. 41.9% (378/902), , respectively
(iii) In patients without delays, the main trigger was concern about the patient

Davies et al. [57]
To identify barriers to activation of the RRS by clinical staff
Cross-sectional survey in one tertiary hospital
68 physicians and 16 nurses on medical and surgical wards
Adherence to six calling criteria: HR, MAP, RR, SpO2, mental status change, and “not” looking right’
(i) The self-reported adherence rate for the six activation criteria of the RRS was ≤25%
(ii) The staff members were most familiar with mental status change (76.2%) and least familiar with “not looking right” (65.5%)

Chen et al. [58]
To test the hypothesis that delayed team calls for deteriorating ward patients were associated with increased mortality
Post hoc analysis of MERIT study in 23 hospitals
3,135 emergency team calls with CAT or MET activation
Patients with delayed activation (any call occurred >15 min after documented MET calling criteria) and hospital outcomes (mortality, unplanned ICU admissions, and cardiac arrests)
(i) In all hospitals, 30.2% (947/3,135) of patients had delayed calls
(ii) In the MET hospitals, the proportion of delayed calls was similar before and after implementation of the RRS
(iii) In all hospitals, delayed calls increased the risk of unplanned ICU admissions (adjusted OR 1.56, 95% CI 1.23–2.04, ) and death (adjusted OR 1.79, 95% CI 1.43–2.27, )

Radeschi et al. [59]
To identify attitudes toward the MET and barriers to its utilization among ward nurses and physicians
Cross-sectional quantitative survey in 10 hospitals
1,812 ward nurses and physicians in hospitals with a fully operational MET system
Attitudes toward the MET and barriers to its utilization
(i) Major barriers to MET activation were (1) nurse referral to the covering physician for deteriorating patients (62%); (2) the reluctance to call the MET in a patient fulfilling the calling criteria (21%) less likely in medical doctors vs. nurses, unaffected by the METal certification
(ii) Medical status, working in surgical vs. medical wards, seniority, and participation in the METal training course were associated with lower likelihood of showing barriers to MET activation

Barwise et al. [60]
To identify delays in RRT activation in hospital
Retrospective observational cohort study in one tertiary academic hospital
1,725 patients and vital signs 24 h before RRT activation
RRT activation and hospital patient outcomes (mortality and morbidity)
Delayed activation: 1 h between the first abnormal vital sign and RRT activation
(i) 57% (977/1,725) of patients had delayed RRT activation
(ii) The delayed group had higher hospital mortality (15% vs. 8%, adjusted OR 1.6, ), 30-day mortality (20% vs. 13%, adjusted OR 1.4, ), and hospital LOS (7 vs. 6 days, relative prolongation 1.10, ) vs. the no-delay group

et al. [61]
To assess differences between ward patients with persistent clinical deterioration admitted to the ICU and those admitted at an earlier stage of deterioration
Retrospective observational study in one tertiary university hospital
80 ICU admissions of 69 patients from hospital wards
Delayed alert: ≥2 warning signs in SBP or SpO2 assessments, 8–24 h before ICU admissions
Admissions to the ICU after delayed alerts
(i) There was a delayed alert in 41.25% (33/80) of ICU admissions. These patients had a higher APACHE II () score, SAPS II () score, MODS incidence () statistically significant, and nonsignificant longer ICU stays ()
(ii) Alerts were most frequently circulatory (33.7%) or respiratory (30%) related and realized by physicians on duty (85.2%)

Gupta et al. [62]
To investigate the impact of delayed RRC activation on patient outcomes
Retrospective observational study in one tertiary hospital
826 RRCs across 629 admissions Delayed call: RRC activation delayed by ≥15 min
In-hospital mortality, hospital LOS, and ICU admission
(i) Delayed RRCs were 24.6% (203/826)
(ii) Patients with a delayed RRC had significantly higher in-hospital mortality (34.7% vs. 21.2%, ) and longer hospitalizations (11.6 vs. 8.4 days, )

Sprogis et al. [63]
To investigate the frequency, characteristics, and timing of the limitation of the clinical instability 24 h before MET activation
Retrospective observational study in one tertiary teaching hospital
200 adult ward patients
UCR criteria breached 24 h before MET activation and in-hospital mortality
(i) 78.5% (157/200) of patients had UCR criteria at least once 24 h before MET activation. In 136/157 (86.6%) of first UCR criteria breaches no documentation was found, and in 91/157 (58%) of them there were no documented nursing actions
(ii) There were suboptimal medical reviews despite activation
(iii) Hospital mortality in patients after MET activation was 12%

MET: medical emergency team; RRS: rapid response system; min: minutes; ICU: intensive care unit; LOS: length of stay; OR: odds ratio; h: hours; ALF: afferent limb failure; HR: heart rate; MAP: mean artery pressure; RR: respiratory rate; SpO2: peripheral oxygen saturation; MERIT: medical early response, intervention, and therapy; RRT: rapid response team; METal: medical emergency team alert; SBP: systolic blood pressure; APACHE II: acute physiologic assessment and chronic health evaluation; SAPS II: simplified acute physiology score; MODS: multiple organ dysfunction syndrome; RRC: rapid response call; UCR: urgent clinical review.