Telephone triage consensus study identifies life-threatening chest pain requiring high priority ambulance response

7th January 2022

A telephone triage consensus study of life-threatening chest pain identified the conditions that require a high priority ambulance response

A telephone triage study has identified a number of potentially life-threatening conditions associated with chest pain that ought to require a high priority ambulance response according to researchers from the Division of Cardiovascular Sciences, Core Technology Facility, University of Manchester, UK.

Chest pain is a common reason for ambulance transport with one study finding that it accounted for 16.4% of acute ambulance transports. However, although the majority of patients with chest pain are admitted to hospital, one study has revealed that only a quarter of those assessed before arriving at hospital had a severe illness. 

In fact, an audit of patients admitted to hospital with suspected acute coronary syndrome (ACS), who were assessed by telephone triage, found that only 1 in 18 of those with chest pain were diagnosed with ACS.

Although telephone triage systems leading to the dispatch of emergency services are able to accurately identify those who require transport to hospital, a 2018 systemic review concluded that ‘there is a very low to low overall level of evidence for the accuracy of medical dispatching systems‘.

Moreover, other research has shown that pre-hospital over triage occurred in more than 70% of cases and for chest pain in particular, this happened in 7.7% of cases but was under triaged in 1.2% of cases. As a result, telephone triage systems need to be able to define the range of conditions that should be identified to ensure that patients receive appropriate care.

For the present study, the researchers used the Delphi approach, which represents a structured process for collection and extraction of information from experts over a series of 1 to 3 rounds, to achieve consensus on which life-threatening emergencies associated with chest pain require an immediate ambulance response.

The researchers defined consensus as > 70% agreement. The team defined priority 1 as a life-threatening and time-critical condition that required immediate intervention or resuscitation and priority 2 which was an emergency that might require urgent assessment, intervention or transport.

Findings

A total of 15 participants including emergency doctors, nurses and paramedics completed the first round and 10 the third round. A total of 10 conditions met the consensus for requiring a priority 1 response after telephone triage which were: oesophageal perforation/rupture; ST elevation myocardial infarction; non-ST elevation myocardial infarction with clinical compromise; acute heart failure; cardiac tamponade; life-threatening asthma; cardiac arrest; tension pneumothorax and massive pulmonary embolism.

An additional six conditions, acute coronary syndrome, supra-ventricular tachycardia, abdominal aortic aneurysm, lower respiratory tract infection with respiratory compromise, pneumothorax, ventricular tachycardia with pulse, met the criteria for priority 2.

The authors concluded that based on these findings, the conditions could be used as a composite primary outcome in future research to derive and validate clinical prediction models to optimise telephone triage for patients with chest pain.

Citation

Alotaibi A et al. Towards enhanced telephone triage for chest pain: a Delphi study to define life-threatening conditions that must be identified BMC Emerg Med 2021.

Early CTCA did not alter clinical outcomes in intermediate risk patients with suspected ACS

4th October 2021

The use of early CT coronary angiography in cases of suspected ACS had no overall effect on one-year cardiac outcomes in intermediate risk patients.

Acute chest pain is a common reason for attendance at an emergency department, accounting for approximately 10% of non-injury-related visits. While chest pain can arise from non-cardiac causes, all those presenting with chest pain will be assessed for acute coronary syndrome (ACS). Prompt treatment is required for patients with obvious clinical signs and symptoms of ACS whereas those deemed to be at either a low or intermediate risk initially undergo observation and further testing only if ACS is suspected. One strategic approach to the assessment of low risk ACS patients, is early computed tomography (CT) coronary angiography (CTCA). This technique has been increasingly used to assess patients with stable chest pain because it has high sensitivity and specificity for the detection of coronary heart disease. Within an emergency care department, CTCA therefore allows for a rapid evaluation of patients presenting with acute chest pain. In fact, one systematic review concluded that the use of CTCA is associated with a reduced length of hospital stay compared to usual care. Furthermore, a 2018 study examining the use of CTCA in patients with stable chest pain, found that over a 5-year period, there was a significantly lower rate of death from coronary heart disease or non-fatal myocardial infarction compared to standard care. However, while studies have focused on patients at low risk of ACS, whether early CTCA is of value in those patients deemed to be at an intermediate risk of ACS is less clear.

In trying to assess the value of early CTCA in patients presenting with acute chest pain and at an intermediate level of risk for acute coronary syndrome, researchers from Edinburgh University, established the RAPID CTCA study. The trial enrolled adult patients with suspected or a provisional diagnosis, of acute coronary syndrome and prior coronary heart disease. These individuals where then randomised 1:1 after admission to hospital to early CT coronary angiography with standard care or standard care alone. The primary outcome was the time to the first event of all-cause death or a subsequent non-fatal type 1 (spontaneous) or type 4b (related to stent thrombosis) myocardial infarction at one-year. Secondary outcomes included the cause of death and subsequent myocardial infarction.

Findings

The study recruited and randomised 1748 patients with a mean age of 61.6 years (64% men), of whom 877 received early CTCA. Overall, 89% of patients had chest pain as their primary complaint, 34% had existing coronary heart disease, 57% raised cardiac troponin levels and 61% an abnormal ECG. The primary outcome all cause death or non-fatal myocardial infarction (both types) occurred in 5.8% of those in the early CTCA group and 6.1% of those assigned to usual care (adjusted hazard ratio, aHR = 0.91, 95% CI 0.62 – 1.35, p = 0.65). Furthermore, there were no significant differences in any of the secondary outcomes. The need for invasive coronary angiography occurred in 54% of those in the CTCA group and 60.8% in the usual care group (aHR = 0.81, 95% CI 0.72 – 0.92, p = 0.001).

The authors concluded that early CTCA for patients with an intermediate risk of ACS did not alter overall coronary therapeutic interventions or one year clinical outcomes but did reduce the need for invasive angiography.

Citation

Gray AJ et al. Early computed tomography coronary angiography in patients with suspected acute coronary syndrome: randomised controlled trial. BMJ 2021

Large variation in laboratory tests for chest pain in emergency departments

12th September 2021

Laboratory tests requested by emergency care clinicians are often outside of guidelines and driven by both local and systemic factors.

Within an emergency care setting, the use of diagnostic tests helps with the detection or exclusion of a disease. Although diagnostic tests only account for a small proportion of a hospital’s budget, between 60 and 70% of all clinical decision-making is estimated to be based on the results of a diagnostic test. Despite this, in a review of studies, it was found that 45% of laboratory tests in healthcare are under-utilised compared to 21% which are over-utilised. In an effort to ensure both consistent and rational use of diagnostic and laboratory tests, the Sensible Test ordering Practice initiative was developed in Australia. However, in an analysis of tests ordered following the introduction of the initiative, it was found that just over a third (34.4%) of laboratory tests requested were unnecessary, i.e., generally not indicated. In trying to gain a better understanding of why such tests were being ordered, a team from the Australian Institute of Health Innovation, Sydney, Australia, undertook a qualitative study with clinicians. The team conducted semi-structured interviews and based on the themes identified developed targeted questions to be used with focus groups and focused on patients who presented with undifferentiated chest pain at an emergency department (ED).

Findings
While clinical staff were fully aware of the need to rationalise requests for laboratory tests, the adherence to sensible test ordering was affected by several local and systemic factors. For example, clinicians would order tests that were beyond the patient’s ED encounter often because of requests from other departmental specialists, e.g., can you also order this or that test. Furthermore, laboratory tests would be ordered in anticipation of the those required by the team admitting a patient, even though such tests were somewhat irrelevant within the ED setting. In other words, clinicians ordered tests beyond their remit to facilitate the entire patient’s hospital journey.

Another factor identified was the existence of conflicting guidelines. Although advice on the required tests were contained with the decision-support, electronic medical record (eMR), clinicians noted for example, that the clinical pathway on the eMR required additional tests to those in the order set for ischaemic chest pain, leading to an inconsistency. Moreover, with limited in-house speciality and diagnostic services in some hospitals, clinicians pre-emptively ordered tests for which they knew there would be a longer turnaround time after hours. Additional and unnecessary tests were also requested when patients were transferred to another centre, simply because clinicians were aware of the need for these tests to ensure acceptance at the receiving centre. Finally, while greater use of technology enabled laboratory testing requests much easier, the existence of multiple order screening within the eMR made it difficult to establish a common ordering process.

Summarising their findings, the authors noted that the variability in ordering of laboratory tests was influenced by requirements for admission, conflicting guidelines, availability of in-house resources and the features of of the eMR system. Given that the ED is perceived as the ‘front door’ it was not uncommon to see the ordering of laboratory tests which were beyond the scope of the ED but pertinent for other or later aspects of patient care. The authors concluded that beyond standardisation of laboratory and clinical decision-support systems, attempts to address the variation in laboratory tests need to address both local and systemic factors.

Citation
Li J et al. Why is there variation in test ordering practices for patients presenting to the emergency department with undifferentiated chest pain? A qualitative study. Emerg Med J 2021.