Integration of POCT into the clinical laboratory
By Matthias Orth MD of the Institute for Laboratory Medicine in Stuttgart, Germany
Unlike regular laboratory analyses, which is performed by clinical pathologists and technicians in the clinical laboratory, Point of Care Testing (POCT) are devices to perform laboratory analyses in the vicinity of the patient by the attending physician or nurses.
POCT is essential in all hospitals, either due to the instability of the analytes (e.g. in blood gas analysis) or the necessity of immediate reporting (e.g. glucose testing to adjust insulin doses) and the very demanding logistics for the alternative, i.e. testing samples in the laboratory. This has led to the development of several devices specially designed for POCT. Not only is the location different for POCT, but the levels of analytical expertise in the ward and the ease of testing are also different.
In general, POCT devices analyse unprocessed samples (e.g. whole blood) and can be run by personnel with only limited training. The devices automatically check the integrity of the analytical procedure and the necessary pre-analytical steps (replacing centrifugation for the separation of blood cells from serum/plasma) are generally performed within the devices.
POCT carries several challenges: the immediate medical response to the results, and the tests in terms of medical analysis by a layperson, demand supervision by analytical experts. In Germany, for example, supervision by the central laboratory is mandated by law and DIN EN ISO 22870 describes in detail the optimal organisation of POCT. The decentralised testing makes this supervision very demanding: a typical 800-bed hospital has about 50 patient sites for glucose testing and about 10 for blood gases; large university hospitals may have several hundred sites in which to perform POCT. The high volume of POCT analyses – in general, about 50-100 tests are performed annually per hospital bed – and the widespread use of electronic patient records (EPRs) should mean an automatically transfer POCT results into the EPR. In general, different POCT devices are connected via Connector software with the laboratory information system (LIS).
Connector software is available from the major vendors of POCT devices (e.g. Siemens, Radiometer, Roche) and from independent companies (e.g. Conworx). This software allows supervision of quality controls and patient results. Depending on the level of compatibility, several functions of the POCT device can be monitored remotely and even some maintenance steps can be started and monitored remotely. Patient results are transferred to the LIS and are then transferred to the EPR. The communication between these systems employs standard protocols, such as HL7, HCM, ASTM Protokoll or POCT1A. While the connection of instruments, supervision of quality controls and managing the device status remotely are easy, the integration of patient reports into the EPR can be challenging. In general, the LIS first generates an order and will then ask for the results. In the case of POCT, the POCT device generates a result (including time stamp and patient data) which is transmitted to the LIS. However, few LIS can generate an order simultaneously with the transmission of results.
From a legal standpoint, those responsible must be indicated on each laboratory report. This is challenging, particularly for POCT results: a high number of people perform these tests (i.e. essentially all nurses and doctors) and the full responsibility for the results is in the department where the analyses have been performed and not in the central laboratory. Taken together, POCT with supervision by the central laboratory can be a very efficient tool for the quick and reliable treatment of patients in the hospital.
01.09.2008
