POC testing speeds up A&E decision making

In A&E departments across the country, the four-hour benchmark set by the Government has proven difficult to achieve. The Telegraph, for example, reported on 6 December 2012 that A&E waiting times exceeded four hours for one-third of patients. One way to speed up decision making and to move patients more efficiently through the hospital is to speed up the time it takes to get test results. Point-ofcare (POC) testing is one way to achieve this goal. In the UK approximately 5% of visits to an A&E department are due to a complaint of chest pain, and up to 40% of emergency hospital admissions are due to chest pain.1-3 POC testing can enable efficiency and productivity improvements; simplify processes and procedures; meet regulatory guidelines and performance measures and reduce staff burden by bringing the focus back to the patient. Technology advances in recent years have also greatly expanded the capabilities of POC testing systems and the menu of POC tests available continues to expand. One proponent of POC testing in the emergency room is Dr Kenneth Blick, a professor of pathology who heads up the clinical pathology laboratory at the University Hospital Oklahoma in the US. Speaking at an Emergency Medicine conference in London, recently, he talked about how and why POC testing has become an integrated part of the test procedure across his institution. The University Hospital Oklahoma campus consists of over 50 buildings and contains two major hospitals – the Presperterian Tower facility, which takes care of adult patients and sees around 70,000 emergency patients every year, and a separate children’s hospital. In recent years, the hospital has experienced a 6%-8% growth in patients year on year in the emergency department (ED). Many of the patients coming through the doors will require tests before a decision on their ongoing care can be made. “This year alone, I expect the clinical laboratory to handle around seven million tests. On average we receive between four and five thousand samples every day. It is a very busy facility,” said Dr Blick. Originally the campus contained a total of six laboratories to serve the needs of the health and science centre. In recent years, however, that figure has been reduced to just one automated laboratory, under Dr Blick’s leadership, following an intensive lean initiative. Explaining the reasons for automating many of the testing processes, Dr Blick said: “Like many other industries, we are suffering from an ageing laboratory workforce with the majority of our laboratory technicians now being 50+ years old. There are no medical technology training programmes in central Oklahoma so we really did need to consider other, better and more efficient ways of doing laboratory tests. “At the same time we focused on how we could eliminate potential errors from occurring in the testing process, and to ensure that we could get the test done and back to the clinician in a timely manner, which had posed problems in the past. In 2002, for example over 40% of tests sent to the laboratory by physicians were ordered ‘stat’. We received so many ‘stat’ test requests that we had to introduce a new category ‘life threatening’ to ensure that we processed the most urgent tests first. “Another area for errors to creep into the system is when moving samples from one tube to another to undertake further tests on a sample and this was something else that we wanted to look at.” It is important for any laboratory to understand that, if there are racks of tests pending in the laboratory there will also be rows of patients sitting around in the hospital waiting for these results. Late laboratory test results will cause delay and worry in the ED. With the US soon to introduce a system that relies on moving patients quickly and efficiently through the hospital to drive reimbursements, this has become a more important consideration for the University Hospital Oklahoma, especially for the ED, where many tests often need to be run on patients before they can be diagnosed and treated. The many visitors to the ED suffering chest pain, for example, will need be to measured for Troponin, the biomarker of choice for the diagnosis of myocardial infarction.4 “We wanted to create a leaner system,” said Dr Blick. “Simply putting more people in the laboratory would not help make the system work any better. However, the use of robotic solutions, expert systems and decision making software together with the introduction of POC testing, where appropriate, has given us extra capacity. “Our lean initiative identified that 58 steps in our laboratory processes – where samples were being touched or moved – did not add any value. Since the introduction of a lean working system and the introduction of automated technologies we have eliminated ‘stat’ testing requests by our physicians by treating every sample as if the patients life was in danger. The laboratory now works on a ‘first in, first out’ basis which has drastically simplified procedures. “It is my belief that the laboratory of the future will see 50% of tests being undertaken at the patients bedside using handheld devices. With this in mind, while redesigning our core laboratory processes we also further developed our point-ofcare solutions. This process began way back in 1985, with us using POC testing when it made sense to, in situations where it is not possible to get results back to the physician quickly enough to make treatment decisions from even a well-run laboratory. “Today we have fully embraced the point-of-care concept. We use i-STAT devices extensively throughout both of the hospitals on the campus. This device allows for a complete chemistry panel from less than two drops of blood in a few minutes by just one person, in a single step. I like i-STAT because its menu has continued to expand over the years, which makes it increasingly more useful. This device has proven to be especially beneficial in the paediatric hospital. It is extremely difficult to get the required 300 mL of blood from a newborn baby that weighs less than 2 lb and our paediatric hospital is now almost exclusively using POC testing, where 30% of the patients are less than very low birthweight and 10% weigh less than 2 lbs.” The i-STAT device is one example of a POC testing solution, which is currently in use in around one-third of US hospitals – approximately 1,000 EDs in the US use the i-STAT analyser. By accelerating the availability of diagnostic test results, it can provide healthcare professionals with the information needed to make treatment decisions, sooner, which can lead to an enhanced quality of care. “In the ED, the POC Troponin test can give a precise and accurate result in around 10 minutes at the patients bedside,” said Dr Blick. “However, the system does still need to be used by, and the results translated by, a qualified physician in the ED and should be used in conjunction with all the other available patient information to make a diagnosis.” Although the majority of patients entering the ED with chest pain will eventually be judged not to have a cardiac problem, this group of patients can create an ED bottleneck unless standardised, protocol-driven processes are employed to accelerate clinical decision-making and expedite patient care.

Cardiac biomarkers

Traditionally, a variety of cardiac biomarkers have been used to aid the diagnosis of myocardial infarction (MI), but today cardiac Troponin has become the established cardiac biomarker of choice. Because cardiac Troponin is based on its cardiac specificity, Troponin is expressed almost exclusively in the heart and is not normally found in the circulation. When damaged, myocytes release cardiac-specific Troponins into the blood and these can be assayed as a measure of myocyte damage. In the UK the current standard policy for dealing with patients admitted with chest pain is to take a Troponin measurement on admission and then again 12 hours afterwards to rule out acute myocardial infarction (AMI).5 “Comparing our POC Troponin test to the one we use in in the core laboratory we have found excellent correlation and accordance between the two systems,” said Dr Blick. “Regardless of the cut points we use, we still get the same degree of correlation, clinically speaking, which has allowed us to move confidently towards the use of a point-of-care Troponin assay test as standard to test for ischaemic damage, and we have created a suitable protocol. “With between 7% and 8% of our ED visits being because of chest pain, we are getting a lot of activity and a great deal of use from this rapid rule-out protocol. The ED physicians are also very comfortable with the system and trust the results. With the i-STAT assay we are now using a twohour rapid rule out protocol with good success and no longer test for CKMB or myoglobin which we found can give more false-positive results. “With the point-of-care solution it is still important to do a delta – timed samples which can be looked at in conjunction with other patient symptoms. It is not advisable to mix and match sample testing systems when doing timed sampling, as all Troponin assays do tend to be a little different,” warned Dr Blick. Indeed this is a point on which the FDA in the US has raised concerns. “However, as long as physicians in the ED and cardiologists are well aware that they cannot mix results this should not present a problem,” said Dr Blick. Since going lean in the core laboratory the facility has been able to turn test results around in less than 30 minutes and, because Troponin is tested in the ED, results for this are available within 10 minutes. “Today, healthcare facilities need to concentrate on moving people through the system more effectively. The laboratory is a key part of this and has an important role to play in helping to decrease patient length of stay. It is important that the laboratory can meet its promised test result turnaround times which enables physicians to adjust their protocols accordingly,” said Dr Blick. “During a laboratory audit undertaken in 2012, we found that every test ordered during the audit period was listed as ‘green’ (non stat). These tests were being ordered by the same group of physicians in our hospital that originally ordered nearly 50% ‘stat’ tests. What is different is that, today, they trust the laboratory to get the result back in time, every time. The strategic use of point-of-care real-time testing has been absolutely essential to our success.” Even though the i-STAT devices are used by physicians and nurses, the laboratory maintains responsibility for all of the point-of-care testing undertaken in the hospital. “The hospital has over 1,000 nurses using the equipment regularly and we have two medical technologists in the core laboratory who are dedicated to managing the point-of-care programme. For example, the reagents first come into the laboratory where initial liquid quality control tests are undertaken. The reagents are then distributed into refrigerators around the hospital ensuring that only quality controlled materials are ever used. The nurses also have to undertake some quality control procedures and again it is the laboratory staff who coordinate all the necessary training for this purpose.