28 May Point-of-Care
diagnostic testing to impact
Point-of-care testing allows diagnoses in a physician’s office, an ambulance, the home, the field or in the hospital. The results of care are timely, and allow rapid treatment to the patient.
ACCORDING TO THE NATIONAL INSTITUTES of Health (NIH), empowering clinicians to make decisions at the point-of-care has the potential to significantly impact healthcare delivery and to address the challenges of health disparities. “The success of a potential shift from curative medicine, to predictive, personalised, and pre-emptive medicine could rely on the development of portable diagnostic and monitoring devices for point-of-care testing.”
- In the earliest days of medicine, healthcare was similar to point-of-care in that it was delivered in the patient’s home through physician house visits.
- As medical discoveries were made and new technologies developed, care then shifted to specialised hospitals with an emphasis on curative medicine.
- Large centralised laboratories were established, with cost-savings realised through the development of automated systems for analysis of patient samples.
- Point-of-care devices were used on a limited basis in the hospital for rapid analysis in intensive care units and for simple home testing, such as with pregnancy test kits.
- Point-of-care testing gives immediate results in non-laboratory settings to support more patient-centred approaches to healthcare delivery.
- The emphasis of care is shifting toward prevention and early detection of disease, as well as management of multiple chronic conditions.
- The National Institutes of Health (NIH) supports the development of sensor and microsystem and low-cost imaging technologies for point-of-care testing. These instruments combine multiple analytical functions into self-contained, portable devices that can be used by non-specialists to detect and diagnose disease and can enable the selection of optimal therapies through patient screening and monitoring of a patient’s response to a chosen treatment.
- Sensor technologies enable the rapid analysis of blood samples for several critical care assays, including blood chemistry, electrolytes, blood gases and haematology.
- Biosensors are used clinically for toxicology and drug screens, measurement of blood cells and blood coagulations, bedside diagnosis of heart disease through detection of cardiac markers in the blood and glucose self-testing.
- Current developments in point-of-care testing are addressing the challenges of diagnosis and treatment of cancer, stroke and cardiac patients.
- The NIH notes that circulating tumour cells (CTCs) that spread, or metastasise, from a primary malignant tumour to distant organs are responsible for 90% of cancer-related deaths, a number
that exceeds 500 000 every year in the United States alone. Early detection of cancer might be possible through capture and analysis of CTCs. In addition, the ability to capture and analyse CTCs in peripheral blood may be used in the development of therapeutic strategies that can be tailored to the individual patient and monitor an individual’s responses to cancer therapies.
- Researchers supported by National Institute of Biomedical Imaging and Bioengineering (NIBIB) have developed a unique microfluidic device capable of efficient separation of CTCs from whole blood. This technology has broad implications both for advancing cancer biology research and for the clinical management of cancer, including detection, diagnosis and monitoring.
- With the development of devices and wireless communication, the way in which doctors care for patients will change dramatically. Patients will play a larger part in their own healthcare. Health will become more personalised through tailoring of interventions to individual patients.
- According to the NIH, “The next decade will bring a new realm of precision and efficiency to the way information is transmitted and interpreted and thus the way medicine is practiced. In the future, clinicians may be able to improve the regulation of diet in infants with inborn errors of metabolism through bedside monitoring. Currently, management of such diseases requires complex testing in a hospital setting. However, researchers are developing a chemical sensor, using a small sample of blood from a finger stick, which changes colour in response to metabolic irregularities. When such abnormalities are found, the diet of the infant can be adjusted immediately to prevent adverse effects such as mental retardation.”
- Low-cost diagnostic imaging devices can be used at the point of care for disadvantaged and under-served patients. The development of low-cost imaging devices could make affordable diagnostic imaging more widely available, particularly in rural settings and small hospitals that do not have these technologies.
- For example, a new method using an optical probe for cervical cancer detection and treatment could significantly lower the mortality rate worldwide.
- “Combining a small optical imaging device with a treatment modality could provide both diagnosis and treatment of cervical cancer at the same time