2nd Managing Deteriorating Patient Conference Nov 2014

Delayed Emergency Team Calls and Associated Hospital Mortality – A Multicentre Study

Associate Professor Jack Chen MBBS PhD MBA(Exec)

Simpson Centre for Health Services Research

Australian Institute of Health Innovation & South Western Clinical School

The University of New South Wales

Outlines

Background

Research Method

Main results

Discussion

Strengths and limitations

Conclusions

Background -1

1. Most unexpected hospital cardiac arrests and deaths are preceded by a deterioration in vital signs (up to 70%-80%)

1. Two essential elements of ‘critical care without walls’ concept (i.e Rapid Response System : RRS)

1) detection of the deteriorating patient and alerting of a rapid response team (afferent arm) ;

2) timely response by an adequately trained and equipped team (efferent arm)

Background – 2

Afferent limb failure :

1. Failure to observe/document the vital signs

2. Failure to activate a RRS even with the existing calling criteria

3. Failure to activate a RRS timely (not delayed)

Efferent limb failure:

1. Failure to arrive on scene timely

2. The composition of the team and skill sets may not be optimal

3. Failure to provide the most appropriate care (critical care/resuscitation versus palliative care)

4. Failure in engagement, communication and handover with the home team

Background -3: Studies on delayed calls to a RRS and associated hospital mortality

1. Boniatti MM & Azzolini N, et al. Delayed medical emergency team calls and associated outcomes. Critical Care Medicine 2014;42(1):26-30.

2. Trinkle RM & Flabouris A. Documenting Rapid Response System afferent limb failure and associated patient outcomes. Resuscitation 2011;82(7):810-14.

3. Calzavacca P & Licari E, et al. The impact of Rapid Response System on delayed emergency team activation patient characteristics and outcomes-A follow-up study. Resuscitation 2010;81(1):31-35.

4. Quach JL & Downey AW, et al. Characteristics and outcomes of patients receiving a medical emergency team review for respiratory distress or hypotension. Journal of Critical Care 2008;23(3):325-31.

5. Downey AW & Quach JL, et al. Characteristics and outcomes of patients receiving a medical emergency team review for acute change in conscious state or arrhythmias. Critical Care Medicine 2008;36(2):477-81.

Background 4: Limitations of the current studies

1. Single centre studies

2. Retrospective in design

3. Small sample sizes

4. Mostly focused on specific calling criteria without including the ‘worried’ criterion (most important criterion for most MET systems and in BTF program, most important for nurses)

5. Mostly on mortality, not using ICU admissions and cardiac arrest as outcomes

6. No comparable data for a Cardiac Arrest Team

Aims of our current study

Using a multi-centre prospective cluster randomised controlled trial data (i.e., from the MERIT trial) to :

1. ascertain the proportion of delayed responses to documented patient deterioration amongst both intervention (ie RRT) and control (non- RRT emergency response) hospitals;

2. test the hypotheses that

a)delayed response might be associated with an adverse patient outcome and that

b)risk factors for a delayed response could be identified

Method

Study design and data

1. The sample size calculation, recruitment, ethical approval, and randomization method have been described previously

2. 12 hospitals were randomized to the RRT arm and 11 to the control arm.

3. Data were collected over 12 months including three phases:

– a 2-month baseline period (baseline),

– a 4-month run-in introduction and implementation period (introduction) and

– a 6-month full implementation and intervention (intervention)

period during which the RRT was operational. 4. In non-RRT hospitals the composition and operation of the cardiac

arrest teams (CAT) remained unchanged.

Definition of ‘delayed call’

1. We defined a ‘delayed call’ as any call that occurred more than 15 minutes after a documented RRT calling criterion.

2. This included both the objective call criteria:

1) airway at risk; 2) seizure; 3) greater than 2 points decrease in Glasgow Coma Scale (GCS); 4) acute respiratory rate abnormalities; 5) acute pulse rate abnormalities; 6) hypotension, and

3. the subjective “worried” criterion.

Patients who were admitted to hospital

within the study period

(N=727153)

Patients who had at least one event

(calls/ICU admission/ CA/death)

(N=11268)

Patients who had at least an emergency

call(N=3135)

Patients who did not have an emergency

call

Patient's first call is a

“Not delayed call”

(N=2188)

Patient's first call is a

“Delayed call”

(N=947)

Patients who had no event

Yes No

Did the patient’s first call occur more than 15

minutes after the observed abnormality of calling

criteria?

Patient outcomes

1. Outcomes:

–unanticipated admission to ICU,

– cardiac arrest (CA)

–death

2.Data linkage: We linked the MERIT study records to individual patient hospital admission records to include all hospital mortality.

Statistical methods

1. Survey Poisson regression and survey logistic regression to adjust for hospital cluster effect

2. Random-effect generalized linear models (binomial and multinomial logistic regression) for risk-adjustment.

3. Risk factors: hospital, patient- and call-related characteristics:

– type of call (delayed versus non-delayed),

– location (urban vs. rural)

– type (teaching vs. non-teaching) of hospital, – patient’s gender, age and baseline risk group, – origin (where the call was made) – time and reason of call

4. Delayed calls and patients with not-for-resuscitation (NFR) order using a survey multinomial logistic regression.

Results: Weekly rate of delayed calls (%) for RRT and non-RRT hospitals and its incidence rate ratio (IRR) over three study periods

Delayed calls and increased risk of death : RRT vs non-RRT hospitals during the 6-month study period

71%

61% 55%

39%

29%

39% 45%

61%

0%

10%

20%

30%

40%

50%

60%

70%

80%

Not delayed Delayed Not delayed Delayed

RRT hospitals Not RRT Hospitals

Survived Died

The relationships between delayed calls and

ICU admission, CA and death during the 6-

month study period (all hospitals combined)

Delayed calls and NFR order given during the 6-month study period (%) by delayed status

79.1

6

7.7

7.2

75.3

5

7.8

11.9

0 10 20 30 40 50 60 70 80 90

No NFR was given

NFR was given before the call

NFR was given at time of the call

NFR was given after the call

Delayed

Not Delayed

Delayed calls and NFR order

1. Compared to patients with a timely call, patients with a delayed call were more likely to be issued with an NFR order after the call (delayed vs. non-delayed: 11.9% vs. 7.2%; P=0.003)

2. This may explain why delayed calls did not show an increased risk of CA in comparison to non-delayed calls.

The predictors of the delayed calls (%)

% of delayed calls by time of the day

0%

5%

10%

15%

20%

25%

30%

35%

40%

45%

% of delayed calls

Discussion -1

1. Delayed calls in response to documented acute patient deterioration were associated with a significant increase in unplanned ICU admissions and mortality.

2. The effect size implies that for every 100 such delays there are about 13 potentially avoidable deaths.

3. The proportion of delayed calls was similar for both intervention and control hospitals prior to RRS implementation.

4. After implementation of a RRS, intervention hospitals had proportionally fewer delayed calls than control hospitals.

Discussion - 2

1. After implementation of a RRS, invention hospitals still had substantial proportion of delayed calls.

2. They were more likely to occur in patients admitted to a rural hospital, to HDU or to CCU, in patients older than 75 years, in those documented with a decrease in GCS or blood pressure, and at night-time.

3. Delayed calls were also associated with an increased incidence of NFR orders being issued after the call.

Strengths and limitations

Strengths:

– only large multicenter study (23 hospitals, over 0.75 million patients and over 3100 calls);

– comparative data, comprehensive outcomes (ICU admissions, CA & deaths);

– based on real world calling criteria (including ‘worried’);

– rigorous stats methods and risk-adjustment for baseline risk-group (based on the Elixhauser’s classification method) and other confounders,

– Explored the possible factors related to delayed calls;

Limitations: short follow-up; undocumented ‘worried’ not included; no reasons for why delay

Conclusions 1. Our study provides strong evidence that delays in triggering an

emergency team response to documented patient deterioration are common

2. Such delays are independently associated with increased ICU admissions and mortality in hospitals with or without a rapid response system.

3. The occurrence of delayed emergency calls is reduced by the implementation of a rapid response system, but the effect is limited in magnitude.

4. Our findings provide further evidence for the importance of the detection and timely response to the deteriorating ward patient, a concept which underpins the logic of rapid response systems.

5. Our findings also suggest the need of monitoring the occurrence of delayed calls, identifying the reason of such delay and developing necessary remedy strategies in reducing such delay.

Acknowledgement

I would like to acknowledge my co-authors Professor Rinaldo Bellomo, A/Prof Arthas Flabouris, Prof. Ken Hillman, Dr. Hassan Hassareh and Dr. Lixin Ou on their contributions to a paper based on which I formed my current presentation. The paper is currently under review by an academic journal.

Thank you !!