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Clin Biochem Rev. 2010 August; 31(3): 99–104.
PMCID: PMC2924130

Integrating PoCT into Clinical Care

Abstract

In South Australia, the Integrated Cardiovascular Clinical Network SA (iCCnet SA) is the provider which enacts the recommendations and policies of the state-wide cardiac clinical network working parties in rural and remote areas by developing appropriate clinical tools.

Pathology tests play a significant role in contributing to best practice for patient diagnosis and management. As most South Australian country hospitals do not have timely access to pathology results, point-of-care testing (PoCT) for troponin and N-terminal pro-brain natriuretic peptide (NT-proBNP) has been integrated into clinical pathways for the management of possible acute coronary syndrome (ACS) and suspected heart failure patients respectively. Compared with control hospitals of similar size and resources, preliminary results from an iCCnet SA regional hospital showed improved patient outcomes for ACS: 30-day readmission rates were reduced from 10.4% to 4.2% (p = 0.03) and there was a corresponding trend in the reduction of in-hospital death rates from 15.8% to 9.8% (p = 0.1).

The establishment of iCCnet SA has improved outcomes for rural patients presenting to hospital with symptoms suggestive of ACS by facilitating the uptake of evidence-based acute cardiac care. Implementation of PoCT equipment into clinical care requires a systematic approach that engages all stakeholders involved in patient care. Provider clinical networks, such as iCCnet SA, provide a structure for effective working relationships between health professionals. PoCT has been critical to the success of the network, but it needs to be implemented within an integrated system of care to produce optimal outcomes.

Integrating PoCT into Clinical Care

The Australian health system is currently facing a range of challenges including an ageing population with increased demand for health services, socioeconomic inequalities, across the board workforce shortages and increased technology.

South Australia’s Health Care Plan 2007–2016 was developed to drive health system changes to ensure the safest, most effective public health care is available to all South Australians. This plan aims to engage clinicians in the process of reconfiguring service distribution, work practice redesign and workforce planning. Importantly it provides the framework for the state-wide clinical networks. The state-wide cardiology clinical network has a steering committee supported by eight workgroups which have scopes with clinical relevance across all stages of the cardiology continuum of care.

Networks primarily provide a structure for effective working relationships within and between different organisations and individuals. A successful clinical network requires service providers to be less constrained by existing professional and institutional boundaries and to shift focus to patient care, clinical management and effective partnerships, thereby ensuring the equitable provision of high-quality clinically effective services.

Pathology tests play a significant role in contributing to best practice for patient diagnosis and management. PoCT, defined as diagnostic testing performed at or near the site of patient care,1 is increasingly being used in Australia to bridge geographical barriers to accessing pathology services. If performed within a quality framework, it can enhance clinical management by providing diagnostic results at the time of consultation.

Implementation of PoCT has to be in collaboration with the clinical team and integrated into the clinical framework of the health service. In this way, it provides the impetus to establish a patient-focused clinical service rather than the silo approach our health system has tended to engender. PoCT even provides a vehicle for scientists to move out of the laboratory and become more intimately involved in patient management.

South Australia has a population of about 1.5 million spread over an area of 978,810 km2. The majority resides in the Adelaide metropolitan area, while about a quarter lives in regional areas.2 The population in the regional areas accesses acute care at 66 public hospitals serviced almost entirely by primary care physicians. Of these hospitals, only 10 have an on-site pathology laboratory, all of which rely on on-call services for out-of-hours cover. The Strategy for Planning Country Health Services in South Australia has addressed this lack of pathology laboratories by stating that ‘At a minimum, all hospitals and health services across country South Australia will have access to expanded point-of-care testing and access to pathology testing facilities’.3

iCCnet SA

The Integrated Cardiac Assessment Regional Network (iCARnet), now known as the Integrated Cardiovascular Clinical Network SA (iCCnet SA), pre-dated but has subsequently closely paralleled the aims, objectives and processes of Health Reform in South Australia. iCCnet SA provides an integrated solution to ensure patients presenting to rural health facilities receive access to appropriate cardiac care. It includes clinical tools, resources and systems designed to support the practice of evidence-based acute cardiac care by practitioners, including nurses, from a diverse range of backgrounds, experience and training.

One of the first major obstacles encountered by iCCnet SA was that although it could produce evidence-based cardiac protocols to improve patient management, most country hospitals were unable to adopt the protocols as they did not have timely access to pathology results. Consultations with medical staff identified this factor as well as access to specialist advice as barriers to practising evidence-based cardiac care.

PoCT was identified as a critical enabler of improved patient management in this situation. Two examples illustrate how it can provide benefit when integrated into clinical care.

1. Management of Patients Presenting to Rural Hospitals with Chest Pain Suggestive of ACS

Patients presenting to the emergency department with symptoms suggestive of myocardial ischaemia require the taking of a clinical history, echocardiography, and measurement of a cardiac marker (troponin). On the basis of these results, the patient can be grouped into one of the following diagnostic categories:

  1. ST segment elevation myocardial infarction
  2. Non-ST segment elevation myocardial infarction
  3. Unstable angina pectoris
  4. Low risk of ACS

The risks of death, recurrent myocardial infarction or other serious complications in patients presenting with chest pain correlate well with these diagnostic categories and with the blood troponin level.4 Troponin is currently the gold standard biomarker of myocardial necrosis due to its high diagnostic specificity and prognostic value in the clinical setting.5 Accurate and timely risk stratification of patients presenting with chest pain and possible ACS is essential for optimal management and highly dependent upon timely access to blood cardiac troponin measurement.57

If iCCnet SA was to depend on traditional pathology services for troponin results for patient risk stratification, it would not be able to meet current recommendations from the American College of Cardiology (ACC) that state that the troponin result should be available within 60 minutes of presentation and preferably within 30 minutes.8 As South Australian rural and remote hospitals without an on-site laboratory had to wait up to 36 hours to receive pathology results, in order to meet the ACC recommendations, PoCT had to be considered.

iCCnet SA has integrated troponin PoCT into an agreed clinical pathway for chest pain/ACS patients presenting to the emergency department. This clinical pathway was designed by cardiologists and has been endorsed by the ACS state-wide clinical network working group. Local doctors are consulted before its implementation which can be modified to suit local needs if necessary. The pathway includes triage protocols, diagnostic and risk stratification protocols and treatment protocols. Timely risk stratification would be impossible without PoCT.

The ACS clinical pathway clearly states at what stages in the patient’s admission troponin testing is required. This is a key component of the pathway as it ensures that all patients receive the correct diagnostic tests at the correct time in the patient’s admission, whilst avoiding over-testing costly to the hospital. The ACS clinical pathway identifies high risk patients requiring transfer to Adelaide for invasive cardiac testing.

Troponin PoCT was introduced into rural hospitals with a good understanding of the limitations of the PoCT method compared with the laboratory method. Clinical staff were trained in the importance of not routinely making clinical decisions on the basis of an isolated troponin result but on using patient clinical information and troponin results run as part of a diagnostic protocol. If suspicious of a cardiac cause for a patient’s chest pain despite all results being negative, it is recommended that the treating doctor contact a cardiologist before the patient is discharged.

Clinical governance for PoCT is underpinned by a formal agreement between the hospital and the network that documents each party’s responsibilities. The network agrees to procure equipment and provide training and support for PoCT while the hospital agrees to participate in quality control and quality assurance programs run by the network.

Although PoCT appears to be simple, if incorrectly performed it may present a risk to patient care, and if used inappropriately or overused, it can lead to significant increases in the cost of patient care. To ensure results obtained are not detrimental to patient care, PoCT should be implemented within a framework of quality standards. This quality framework should include operator education, training and competency, quality control, proficiency testing and accreditation. Continuing medical education and training of hospital staff on use of the protocol and PoCT reinforces correct use of the clinical pathways.

To measure patient outcomes following the implementation of iCCnet SA, we used the Integrated South Australian Activity Collection inpatient separations database which collects patient demographics, primary and secondary diagnoses, procedure codes, nature of separation (discharged home, transfer to tertiary hospital), and admission and discharge dates. Preliminary results from an iCCnet SA hospital and two control sites of similar size and resources showed that implementation of our model of care has significantly reduced the 30-day readmission rate for ACS, p = 0.03 (Table). An associated but not statistically significant decrease in the number of ACS in-hospital deaths, from 15.8% before network implementation to 9.8% (p = 0.1) was also observed. More detailed analyses are currently underway to determine whether this decrease is sustained and whether it reflects a regional trend.

Table.
30-day readmission and in-hospital death rates of an iCCnet SA site compared with two control sites.

2. Implementation of NT-proBNP to Identify Patients Requiring Echocardiography to Diagnose Heart Failure

Heart failure is defined as a complex clinical syndrome resulting from a cardiac disorder that impairs the ability of the heart to fill with or eject blood.9 The prevalence of heart failure increases sharply with age. It is estimated that at least 300,000 Australians have chronic heart failure, with 30,000 new cases diagnosed each year.10 As the diagnosis is commonly missed in mild cases, the actual numbers could be as high as twice these estimates. Heart failure accounts for approximately 1% of the total health care budget.11

Symptoms of heart failure are non-specific, with the primary clinical manifestation of acute congestive heart failure (CHF) for patients presenting to the emergency department being dyspnoea. Diagnosis is complicated because patients with other critical illnesses such as ACS, pulmonary embolism, chronic obstructive pulmonary disease and pneumonia present with similar symptoms. Echocardiography is needed for patients to confirm or rule out heart failure where suspected. Clark et al. reported a significantly higher prevalence of CHF in rural and remote regions (19.84/1000) and urban areas (19.01/1000) compared with capital cities (16.94/1000), p<0.001.12 This higher prevalence coupled with the limited specialist and echocardiography services available in rural and remote regions makes CHF a significant health problem in these areas.

The Cardiology Clinical Network Heart Failure Working Party was asked to develop a pathway to improve management of heart failure in South Australia (Figure 1). The pathway consists of clinical assessment, pathology and other diagnostic tests, interpretation of test results, medications, and short-term and long-term management of the patient.

Figure 1.
Heart failure protocol.

Both NT-proBNP and brain natriuretic peptide (BNP) have proven to be powerful tools in excluding CHF when assessing dyspnea.13 NT-proBNP is especially useful as it can effectively rule out heart failure without the need for echocardiography if the patient’s result is <300 ng/L.14 As country patients may have to travel long distances for an echocardiogram, eliminating unnecessary ones in this way benefits an overstretched service as well as saving patients unnecessary travel.

Both NT-proBNP and BNP can be performed by laboratory methods or by PoCT. Considering the location of pathology laboratories in relation to the number of CHF cases (Figure 2),15 it is clear that PoCT methods for natriuretic peptides needed to be considered seriously for rural and remote health centres. Introduction of PoCT into the clinical setting includes the education of medical and nursing staff on how the PoCT result is interpreted in conjunction with the patient’s clinical picture using the designated pathway.

Figure 2
Prevalence of heart failure in Australia and location of pathology laboratories.

The heart failure protocol standardised the natriuretic peptide testing to NT-proBNP (rather than BNP) in South Australia as all hospitals, regardless of location, have access to this test through either PoCT or laboratory pathology services. As the workgroup has specified NT-proBNP as the preferred test, all sites will be encouraged to use this test to ensure standardisation.

As the same cardiologists service all 66 rural and remote hospitals in South Australia, it has been vital that the PoCT services are standardised. This is especially important for cardiac PoCT tests such as troponin (troponin T vs troponin I) and natriuretic peptides (BNP vs NT-proBNP), as test results are communicated over the phone from hospital staff to cardiologist. As different platforms can have very different reference intervals, cardiologists must be aware of the platform/test being performed to ensure that the advice they give to the rural hospital is appropriate. Having different platforms across different hospitals could potentially lead to confusion with incorrect clinical advice being given for the management of these country patients.

Conclusion

South Australia’s health structure has allowed the cardiology clinical network steering committees to provide clinical expertise and recommendations with the aim of improving cardiac outcomes across the state.

The establishment of iCCnet SA has improved outcomes for rural patients presenting to hospital with symptoms suggestive of ACS by facilitating the uptake of evidence-based acute cardiac care. PoCT, particularly for cardiac troponin, has been critical to this success, but not sufficient alone. The recent introduction of a heart failure clinical pathway for patients presenting to the emergency department with symptoms suggestive of acute CHF, along with PoCT for NT-proBNP in rural and remote hospitals, is anticipated to improve patient outcomes in a similar manner.

An integrated system of care incorporating PoCT and improved clinical support for primary care practitioners at a number of levels in the care of acute cardiac patients is required to produce optimal outcomes. This can only be achieved by extensive consultation with all key stakeholders to develop systems of care that include the whole clinical picture.

Footnotes

Ms Tirimacco is Chair of of the AACB PoCT Working Party Committee.

Competing Interests: The authors receive research support from Roche, Hemocue and REM Systems.

References

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Articles from The Clinical Biochemist Reviews are provided here courtesy of The Australian Association of Clinical Biochemists