Point of care testing

4 and 10) and their integration into small, self-contained, analytical systems, the means became available of returning to POCT with a goal of reducing TAT of test results and improving patient management (Box 12-2). 

The following sections of this chapter will describe the technology available for POCT and the organizational factors that are important when POCT is implemented in a healthcare setting. The chapter concludes with a short discussion of the future of POCT. 

The technical advances that have catalyzed the evolution of POCT instruments are the development of a miniature sensor to measure electrolytes, blood gases, and other analytes and the development of dry, stable reagents in disposable unit-dose devices. Although the throughput of tests for these systems is low, the time required to produce the results is usually short. These systems are often small enough to be portable, further enhancing the possibility of bringing tests to the patient.  

Topics to be discussed in this section include (1) instrument requirements, (2) instrument and operator interface design, (3) examples of POCT devices, and (4) the role of informatics. Readers requiring additional information are referred to more comprehensive texts or to the vendors of POCT devices. 

All POCT devices should meet the following overall requirements (1) simple to use, (2) robust in terms of storage and usage, (3) producing results concordant with the central laboratory and consistent with the clinical need,and (4) capable of being safely operated. Additional characteristics and requirements of POCT devices are listed in Box 12-3. 

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Such electrodes should be sufficient as a reference electrode for short-term usage or as a disposable electrode. However, the requirement of a pre-hydration time may limit its applications for fast measurements, such as POCT (the point-of-care testing), due to its slow response time. In fact, the lack of long-term stable microreference electrodes will continue to hamper the development of integrated pH sensing systems. 

A.J. Tudos, G.A.J. Besselink, and R.B.M. Schasfoort, Trends in miniaturized total analysis systems for point-of-care testing in clinical chemistry. Lab on a Chip 1, 83-95 (2001). 

Rapid antigen and point-of-care tests, direct fluorescence antibody test, and the reverse-transcription polymerase chain reaction assay may be used for rapid detection of virus. 

Microfluidic devices have gained importance and utility for analyses of various molecules, including drugs and their metabolites. Vrouwe et al. [151] developed NCE for point-of-care testing of lithium in blood samples. The device consisted of a glass chip coupled with a conductivity detector. The authors tested this system for lithium analysis in five patients in the hospital. Furthermore, the authors reported that sodium, lithium, magnesium, and calcium were separated in <20 seconds. The authors claimed that the NCE system provided a convenient and rapid method for point-of-care testing of electrolytes in serum and whole blood. 

At the same time we would like to welcome Dr. Gregory Makowski, from the University of Connecticut Health Center in Farmington, who has taken up the Editor s baton. With his research interests in genetic diseases, toxicology, and point-of-care testing, Dr. Makowski is the ideal person to develop this series further. 

Von beckerath N, Pogasta-Murray G, Wieczorek A Schomig A, Kastrati A, Correlation between platelet response units measured with a point-of-care test and ADP-induced platelet aggregation assessed with conventional optical aggregometry. ESC 2005 P2936 (abstract)... 

Korponay-Szabo IR, Raivio T, Laurila K, Opre J, Kiraly R, Kovacs JB, et al. Coeliac disease case finding and diet monitoring by point-of-care testing. Aliment Pharmacol Ther 2005 22 729-737. 

Blood for analysis may be obtained from veins, arteries, or capillaries. Venous blood is usually the specimen of choice, and venipuncture is the method for obtaining this speci-men. In young children and for many point-of-care tests, skin puncture is frequently used to obtain what is mostly capillary blood arterial puncture is used mainly for blood gas analyses. 

Point-of-care testing (POCT) is a rapidly growing component of laboratory testing. It is known by a variety of names, including near-patient, decentralized, and off-site testing and is discussed in detail in Chapter 12. In addition. 

Modified from Maclin E, Mahoney WC. Point-of-care testing technology. 

Modified from loiies R, Infoimatics and point-of-care testing. In Price CP, Hicks JM, eds. Point-of-care testing. Washington DC AACC Press, 1999 175-95. 

I BOX 12-4 Assessing the Need for a Point-of-Care Testing Service... 

The Main Elements of a Point-of-Care Testing Training Program... 

Azzazy HM, Christenson RH. Cardiac markers of acute coronary syndromes is there a case for point-of-care testing Clin Biochem. 2002 35 13-27,... 

Burnett D. Accreditation and point-of-care testing. Ann Clin Biochem 2000 37 241-3. 

Calatzis A, Heesen M, Spannagl M. Point-of-care testing of hemostatic alterations in anaesthesia and intensive care. Anaesthesist 2003 52 229-37. 

Creed GM. Point-of-care testing in the United Kingdom. Crit Care Nurs Q 2001 24 44-8. 

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