Point-of-care testing: helpful when things need to happen quickly?
Point-of-Care Testing: Helpful When Things Need to Happen Quickly?
Advances in technology and analysis techniques, as well as the increasing miniaturization of laboratory equipment and processes, make it possible: patient-side laboratory testing, better known as point-of-care testing or POCT. There are many POCT projects and all of them promise a rapid diagnosis as well as economic advantages. But are these tests also suited for everyday medical testing?
Whether it’s to determine blood glucose levels, a heart attack or to conduct a blood gas analysis: point-of-care testing (POCT) can be used in many different areas for clinical diagnostics purposes or to track treatment progress. A patient can be diagnosed with diabetes mellitus right in the ambulance for example. Yet a patient is also able to measure his/her own blood glucose level to adapt the treatment accordingly. To that effect, POCT can not only be used in hospitals or medical offices but also in home health care.
When things need to "happen quickly": POCT in the emergency department
The big advantage of POCT is its speed. Sample transportation can be omitted and laboratory testing takes place on site – in the operating room, the hospital ward or in the ambulance. "Using POCT makes the most sense whenever things need to happen quickly and where every second counts. And that is the case in the large emergency sector," says Professor Peter Luppa, Assistant Medical Director at the Institute of Clinical Chemistry and Pathobiochemistry, University Hospital on the right banks of the Isar, Technical University of Munich. "It’s wonderful when a central laboratory is able to deliver a test result within half an hour but this is not the case in many hospitals." Smaller hospital facilities, in particular, don’t have their own in-house central laboratory and rely on external laboratories for testing. In doing so, it may take several hours from the time a sample is taken until the test result, which is a problem when it comes to acute cases.
For example, when a patient is admitted to the emergency unit with chest pain, he/she needs to be diagnosed as quickly as possible when a heart attack is suspected – or this needs to be eliminated as a cause – to start immediate therapy. This is done by measuring the serum cardiac marker Troponin. If the value is positive, the patient is immediately transferred and treated accordingly.
At the same time, a rapid diagnosis also has another positive effect: it relieves overcrowded emergency rooms. "If certain diseases have been eliminated as a cause, patients can be sent home again. At least, in theory, POCT is able to assist in this case," says Luppa.
Having said that, as is the case with many things, point-of-care testing doesn’t just have advantages. When POCT is increasingly used instead of sending the samples to the laboratory, it takes a toll on the nursing staff. "Especially in the outpatient area, the nursing staff has to perform added tasks it didn’t have to do before. Thanks to POCT, staff now has to draw blood samples and also conduct their own analysis. That’s when nursing staff quickly comes under time pressure," warns Luppa.
Added to this is the fact that the staff does not have the respective medical technology training, which may result in an incorrect operation of POCT diagnostic devices. David Hain, CEO of Hain Lifescience, believes that "POCT has its very own issues. It could definitely happen that a test result is not interpreted correctly due to insufficient knowledge of the staff. This may result in the wrong treatment." This is why staff training is crucial because the best point-of-case testing is useless if the staff is unable to apply it correctly.
Whether POCT pays off as a diagnostic tool should be measurable by using an evidence-based approach. This is the case with blood gas measurements in the operating room and in the intensive care unit, for example, but also with INR level measurements of patients taking the blood thinner Marcumar. "These patients benefit from INR level measurements. They self-monitor the dosage of Marcumar as a blood-thinning drug. And this is clearly an evidence-based use of POCT," according to Luppa.
"At Hain Lifescience, we have increasingly relied on a central laboratory," explains Hain. "That’s simply because point-of-care testing is rare in countries with great health care systems like Germany or the U.S. for example. You simply don’t need this type of testing." Luppa also sees the future of POCT less in the industrialized countries and more in developing nations. "Here in Germany where we largely have a well-functioning health care system, POCT presents more of a specific level of improvement – though the changes are only marginal. Meanwhile, POCT is well-positioned and exactly right for use in developing nations."
Many different types of uses: drug dosage, respiratory disorders, infection detection
There are a number of projects aimed at the development of point-of-care diagnostics. The target group of the NANODEM (NANOphotonic DEvice for Multiple therapeutic drug monitoring) project, for example, is transplant patients where a monitoring of immunosuppression in the blood is necessary.
TheISyPeM II project (Intelligent Integrated Systems for Personalized Medicine) is also aimed at the monitoring and dosing of medication. To do this, the project develops a POCT device that measures the concentration of medication in the blood – by only using one drop of blood. "Basically, it is "mix and measure" no complicated external sample preparation needs to be done," explains Professor Jean-Manuel Segura of the Institute of Life Technologies, HES-SO Valais, who is in charge of the blood test for the project. He considers neonatology the primary application area. When a newborn suffers from a bacterial infection, for example, and receives the Tobramycin antibiotic, the drug has to be measured and adjusted on a regular basis. "Currently, for a test 500 microliters are needed. This is especially difficult for children or neonates. With our device, it would be enough to take 20 microliters which is just a small drop of blood. That is the clear advantage. It is less risky for the child."
Meanwhile, another project wants to fight chronic respiratory diseases like asthma and chronic obstructive pulmonary disease (COPD) with the help of POC testing. The EXASENSpilot project – funded by the German Federal Ministry of Education and Research (BMBF) – focuses on lab-on-a-chip technologies based on optoelectronic and photonic technologies. The goal is to develop a measurement platform that delivers disease-relevant information within a very short amount of time. Embedded in an intuitive device, it is intended for use in both a doctor’s office and at home – and is thus also suited for use in telemedicine.
Luppa sees the evolution of point-of-care testing for infectious diseases – both bacterial and viral infections. "Presently, these proofs are still not widely used but a revolution is apparently looming. After all, it is always a blessing when we know the type of infection patients suffer from. Patients can subsequently be isolated from other patients and explicitly treated."
For the future, Luppa wants "everything to be covered that’s vital and leads directly to a therapeutic effect." Segura also sees great potential in point-of-care diagnostics, "especially if tests can be made more compact and easier to handle."
The article was written by Olga Wart and translated from German by Elena O'Meara. MEDICA-tradefair.com