Point Of Care Testing


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  • Point of care testing (POCT) is a new concept in laboratory medicine that is widely used at present. It is the new advent that helps ease medical care in the present day. The knowledge on the POCT medicine is very important and necessary for the general practitioner. In this specific book, the author summarizes, presents and discusses on the concept of POCT, its importance and examples of important POCT tools.
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Point Of Care Testing

  1. 1. Clin Lab Med 27 (2007) 893–908 Point of Care Testing James H. Nichols, PhD, DABCC, FACB Tufts University School of Medicine, Baystate Medical Center, Department of Pathology, 759 Chestnut Street, Springfield, MA 01199, USA Point of care testing (POCT) is laboratory diagnostic testing performed at or near the site where clinical care is delivered. POCT provides the advan- tage of rapid test results with the potential for faster patient treatment. With increasing pressure on physicians to see more patients and spend less time with each patient, POCT has become a popular means of meeting the de- mands for faster laboratory testing. POCT devices use small amounts of un- processed specimen, so less blood is required, allowing the use of fingersticks over the risk of phlebotomy. A wide menu of analytes is available, including blood gas, electrolytes, pregnancy, cardiac, and infectious disease testing (Box 1). The convenience of POCT has led to broad adoption of POCT into clinical practice over the past 20 years. Current estimates indicate that POCT encompasses nearly one third of the in vitro diagnostic testing market and is growing at a rate of 9%, with annual sales of $7 billion world- wide [1,2]. Federal regulations have facilitated the use of simple POCT devices. Al- though the federal Clinical Laboratory Improvement Amendments of 1988 (CLIA’88) set minimum standards for validation and quality control of lab- oratory tests, a separate category of simple testing called ‘‘waived’’ tests was developed. CLIA ‘‘waived’’ tests are examinations or procedures that ‘‘are cleared by the United States Food and Drug Administration (FDA) for home use; employ methodologies that are so simple and accurate as to ren- der the likelihood of erroneous results negligible; or pose no reasonable risk of harm to the patient if the test is performed incorrectly’’ [3]. Although lab- oratories adopting nonwaived testing must perform initial and ongoing de- vice evaluation, document operator training and competency, subscribe to proficiency testing, and develop a quality assurance program, including daily performance of quality control, laboratories adopting waived tests only need to enroll in the CLIA program, pay a biennial certification fee, E-mail address: james.nichols@bhs.org 0272-2712/07/$ - see front matter Ó 2007 Elsevier Inc. All rights reserved. doi:10.1016/j.cll.2007.07.003 labmed.theclinics.com
  2. 2. 894 NICHOLS Box 1. Current clinical laboratory improvement amendments waived category tests available Diabetes testing Glucose Ketone Hemoglobin A1c Hemoglobin Reproductive testing Human chorionic gonadotropin (pregnancy) Luteinizing hormone and Fern Test (ovulation) Follicle-stimulating hormone (menopause) Renal function Urine dipstick Microalbumin Infectious disease Streptococcus HIV Helicobacter pylori Influenza A and B Mononucleosis Respiratory syncytial virus Trichomonas pH and amines (bacterial vaginosis) Occult blood Drugs of abuse testing Therapeutic drug monitoring (lithium) Lipids Cholesterol High-density lipoprotein Low-density lipoprotein Triglycerides Brain natriuretic peptide Liver function Aspartate aminotransferase Alanine aminotransferase Coagulation (prothrombin time/international normalized ratio) Tumor markers (bladder tumor-associated antigen) and follow manufacturer’s test instructions. Because of these simple regula- tory requirements, the number of CLIA waived tests has grown from 8 in the original CLIA ’88 regulations to more than 40 tests today. Additionally, the number of certificate of waiver (COW) laboratories has increased from
  3. 3. POINT OF CARE TESTING 895 20% to 58% of the nearly 180,000 CLIA-certified laboratories [4]. Most of these are physician office practices. This rapid increase in the use of POCT has led to concern about the qual- ity and risks of POCT. Home blood glucose testing devices represent the largest number of complaints filed with the FDA for any medical device, with more than 3200 incidents, including 16 deaths [5,6]. Poorly maintained urinometers and blood gas analyzers that are carried between patient rooms can act as infectious reservoirs for nosocomial and antibiotic-resistant or- ganisms [7,8], and blood glucose testing devices have been linked to trans- mission of hepatitis B infection among patients at nursing homes in California, Mississippi, and North Carolina [9]. A 2001 state survey of COW laboratories found that 21% of laboratories were not performing quality control as required, 12% failed to keep manufacturer’s package in- sert, 21% failed to check the package insert for changes, 18% failed to re- port results in units or as recommended in package insert, 6% were using expired reagents, and 3% were not storing the reagents as recommended [4]. Although POCT devices may seem simple, these devices are not innocu- ous. Consumers and operators of these devices need to be aware of the po- tential risks and take steps to ensure appropriate test quality. This article reviews several strategies to enhance the quality and integration of POCT into patient care. Point of care testing organization Despite the illusion of simplicity, in practice, POCT devices can be af- fected by several factors beyond the analytic process, including the environ- ment and the operator. POCT presents challenges in managing the preanalytic, analytic, and postanalytic processes similar to centralized labo- ratory testing. Systematic reviews of the literature find that most laboratory errors occur in the preanalytic and postanalytic phases of the testing pro- cess, outside of the walls of the traditional laboratory [10]. This is the setting where POCT is conducted, and there is ample opportunity for error. Unlike the traditional laboratory where the bulk of testing is conducted on a few analyzers by a core group of skilled and trained technicians, POCT is conducted by a variety of clinical staff on multiple devices in many loca- tions. An average hospital may have thousands of operators conducted test- ing with hundreds of devices at more than 30 to 50 locations (Box 2). This staff is focused on patient care and not on the nuances of instrument calibra- tion and quality control. In fact, most clinical staff involved in POCT are not trained in laboratory processes and do not know what quality control is or even why controls are important. Getting all staff to perform POCT the same way every time that the test is conducted presents a logistical chal- lenge. Managing the volume of paperwork from training, test results, bill- ing, quality control records, and other documentation can become
  4. 4. 896 NICHOLS Box 2. Test operational features Laboratory testing One site Limited instruments perform bulk of analyses Limited staff with focus on sample analysis Staff with laboratory training and experience POCT Multiple sites Multiple devices Multiple staff with focus on patient care Staff with clinical training, not laboratory education overwhelming. Laboratory professionals provide an important role as a re- source of technical information and can assist in organizing a POCT pro- gram, establishing policies, standardizing training, and supporting the overall quality management of POCT whether conducted in a single-physi- cian office or in a large health system. The ‘‘laboratory director’’ on the CLIA certificate plays a key role in managing POCT. Under CLIA’88, every site with a separate mailing ad- dress must have a CLIA certificate if it is performing testing for patient care. A laboratory director is responsible for all testing performed under a CLIA certificate. Although some activities, like the daily review of quality control, can be delegated to other qualified staff, the CLIA laboratory direc- tor is ultimately responsible for all testing and quality of test results pro- duced under his/her name. The consequences for noncompliance with federal CLIA regulations can result in limitations of a site’s ability to per- form testing and can sanction the laboratory director on the CLIA certifi- cate, preventing that individual’s ability to bill Medicare for laboratory services for periods of up to 2 years or more. The laboratory director must be a physician, pathologist, or doctoral- level laboratory scientist with laboratory experience and training; however, the experience and training are not required for sites with a COW. Thus, a doctor in a physician’s office practice can act as the laboratory director for that office if the site only performs simple waived testing. For more com- plex testing, the laboratory director must be a pathologist or a doctor with some laboratory training and experience. The site can contract for external consulting with a qualified laboratory director, but federal and state regula- tions limit the number of CLIA certificates to three to five sites for any in- dividual laboratory director. This ensures that the laboratory director has time to spend at each site and is actively participating in and aware of the testing conducted under his/her name.
  5. 5. POINT OF CARE TESTING 897 Although the limited testing performed in a small physician office gener- ally can be managed between the laboratory director and one or two staff members, management of POCT in larger institutions and hospitals requires a team of staff to coordinate the testing. With multiple staff, devices, and lo- cations, the volume of testing in hospitals requires a more formal POCT program organization (Fig. 1). One CLIA certificate can cover all POCT conducted within the hospital, with the laboratory director coordinating the testing through the assistance of a dedicated staff member (POCT coordinator) or team (POCT team led by a POCT coordinator). The POCT coordinator or team handles the routine technical, training, and troubleshooting tasks of ensuring that the POCT devices are functioning properly and that the staff at each site is trained and competent to be per- forming the tests. This team also is responsible for ensuring site compliance with institutional policies and overall institutional conformity with federal and state regulations. The laboratory director can delegate these tasks, but should ensure control over the entire program by setting and reviewing policies and procedures, as well as assisting in the clinical interpretation of POCT results and consulting with physicians on unusual cases when the test result does not match the clinical symptoms. Together, the POCT team, led by the laboratory director and supervised by the POCT coordinator, acts as an administrative group to orchestrate the POCT processes that will meet patient and physician needs (see Fig. 1). Standardization POCT is not just a faster laboratory test. POCT devices are different methodologies from core laboratory methods, and the test limitations and Laboratory Director POCT POCT Coordinator Committee Unit Nurse Clinic Physician POCT Contact Staff Contact Member Nursing Member Purchasing Member Administration Member Fig. 1. Organization chart for POCT management in a hospital.
  6. 6. 898 NICHOLS interferences can vary significantly. Glucose meters, for instance, can gener- ate widely disparate results compared with core laboratory methods in pa- tients who have ketoacidosis. This effect is noted in meters from many manufacturers and is more than a matrix difference (ie, capillary versus ve- nous sample). Most importantly, the differences are noted in the same spec- imen and tend to resolve as the patient is hydrated and ketoacidosis declines. Transcutaneous icterus devices generate comparable estimates to total se- rum bilirubin, except when bilirubin is elevated (O12 mg/dL). These icterus devices are contraindicated in premature infants, babies undergoing photo- therapy, and certain ethnic groups with dark skin. Conversely, bilirubin and glucose analysis using serum or plasma in a core laboratory do not have these types of issues. Therefore, implementation of POCT devices must con- sider the test limitations, and the quality assurance program should ensure that the test is not used in patient populations that are contraindicated or known to generate misleading results. These cases illustrate the need for evaluating a POCT device in the spe- cific patient populations in which the test is intended to be used. If limita- tions and differences between POCT and core laboratory methods are known before use in patient care, steps can be taken to prevent the misinter- pretation of test results. For instance, prior knowledge of glucose meter is- sues in patients who have ketoacidosis would raise concern about the use of a glucose meter to screen patients in the emergency room. During triage, routine screening of all patients could generate misleading results in patients who have ketoacidosis. A physician should examine emergency patients for symptoms of ketoacidosis before testing with a glucose meter. By examining patients before testing, staff can ensure that this problem is prevented. An alternative practice could screen patients for positive urine ketones before the use of a glucose meter. Thus, implementation of POCT requires the selection of devices that match patient care needs, as well as appropriate deployment to ensure quality results and prevent known limitations. Standardization of POCT technologies can help to improve quality in multiple ways. Use of a single manufacturer or device may allow for sharing of one policy and procedure across multiple sites. Training is simplified, be- cause one common checklist can be used. Testing also is more consistent, because staff who float between sites will not have to remember the opera- tion of the same test from different manufacturers, each likely to have dif- ferent testing protocols. Most importantly, test interferences and result differences are minimized by limiting the number of unique devices in use. In summary, standardizing to a single POCT technology (eg, a single glu- cose manufacturer or single pregnancy test) is the most important step that an organization can take to improve quality. By preventing sites from randomly implementing POCT devices and narrowing each test to a single device/manufacturer, testing will be uniform, and patients will expe- rience the same test as they move from one site to another within an insti- tution or health system. This ‘‘continuity of care’’ is a key goal in health
  7. 7. POINT OF CARE TESTING 899 care that is being stressed by the Joint Commission and the College of American Pathologists (CAP) in their hospital and laboratory accreditations. A POCT committee consisting of multidisciplinary membership can help to facilitate the standardization of POCT technologies in an institution by providing a forum for review of new test requests, establishment of sys- tem-wide policies, and discussion of POCT issues (see Fig. 1). Committees composed of laboratory, physician, and nursing members provide balance and viewpoints from different perspectives. The laboratory is knowledgeable about test limitations and quality assurance/control processes. Nurses con- duct the testing and have operational concerns to bring to the table. Physi- cians use the POCT results in patient management and will have issues regarding clinical interpretation of POCT. Additional members are useful, depending on the issues being debated, and could include purchasing, ad- ministration/budgeting, pharmacy, and hospital quality improvement. For example, the POCT committee is important to resolving conflicts involving POCT and depersonalizes the responsibility of decision-making from a single individual to an entire committee. Selection of a device for hospital use may involve evaluation of the device and review of the data by the POCT com- mittee for approval/disapproval or limitation of use. The POCT committee could review the data for a transcutaneous icterus device and limit its use to the well baby nursery, because this device is known to not perform well in premature infants (ie, preventing its use in the neonatal ICU). This would be a committee decision to set a hospital policy of where and how the device would be used. Physicians who are not comfortable with this policy could address the committee, rather than directing comments to any single indi- vidual. Therefore, the POCT committee assists in management by offering a forum for discussion of issues and establishes consensus-driven decision making. Point of care testing and the environment Unlike laboratory testing in the well-controlled and monitored environ- ment of a core laboratory, POCT takes place in a variety of settings and conditions. Many POCT kits contain reagents that are sensitive to heat, cold, light, and moisture. Consumers need to be aware that storage and use conditions can affect the quality of results. In most cases, however, com- promised reagents still provide results, although perhaps not always accu- rate ones. Care must be taken in shipping so that tests kits do not freeze or become overheated. Pregnancy tests contain protein antibodies that can be dena- tured at high and low temperatures. Freezing during ground transportation in the winter months and cooking the reagents during summer months can affect test performance. Blood gas cartridges contain liquid reagents that are calibrated to known levels of gases. Extremes of environment, freezing and
  8. 8. 900 NICHOLS heating, can alter tonometered blood gas levels. On arrival in the clinic or hospital, test kits should be checked for appropriate function by analyzing specimens with known values, such as quality control solutions or previ- ously analyzed patient samples. Tests should be stored as recommended by the manufacturer under tem- perature- and humidity-controlled conditions. Urine dipsticks contain chemicals that are degraded by light, heat, and humidity. These tests should be stored in dry cabinets and not near sinks, patient restrooms, or other sources of moisture. Caps should be replaced and tightly covered after use to prevent humidity in the air from contacting the dipsticks. Occult blood cards also are sensitive to light, heat, and humidity. These cards should be stored in a dark, dry cabinet away from windows, radiators, and other sources of light and heat. The environment also can affect POCT analysis, and staff should be aware of potential environmental factors that can impact test results. Fluo- rescent lighting, for instance, can affect color discrimination on urine dip- sticks, so development is recommended under bright incandescent lighting conditions. Visiting nurses who perform health care in patient homes often use POCT devices. Care needs to be taken to protect the tests from the en- vironment. Tests or kits left in the trunk of a car or back of an ambulance can freeze in the winter and cook in the summer months. Devices like glu- cose meters have internal checks within the device that prevent analysis if the temperature or humidity is too low or high. These checks, however, only monitor the electronics of the device and not the chemistry of the test strips. Staff needs to be aware that the test strip and the device combine to form a result, and quality requires managing the exposure of the strip and device to environmental extremes. Blood gas devices are calibrated at sea level. Performance of POCT at higher elevations, in helicopters, or in pres- surized airline cabins can affect the calibration and bias patient results. The manufacturer should be consulted if blood gas analysis is going to be con- ducted in different locations or during mobile transport. Thus, a variety of environmental factors that can affect POCT results should be managed to ensure quality test results. The point of care testing operator Analytical technique can affect the quality of POCT results. Although most core laboratory instrumentation is highly automated and nearly inde- pendent of operator technique, POCT uses predominantly simple devices or manual, visually interpreted colorimetric tests that are reliant on consistent technique. Even when following manufacturer instructions, problems can arise. Samples can be collected in the wrong anticoagulant, and delays in analysis can lead to clots. Bubbles can be injected into analyzers, and blood gas specimens can be exposed to air. Too much or too little sample can be applied. Tests can be overtimed or undertimed. Staff can program devices
  9. 9. POINT OF CARE TESTING 901 with the wrong lot-specific calibration codes. Although some POCT devices have internal control mechanisms to detect bubbles, clots, sample flow or volume, and other common operator variables, these issues are primarily unintentional and not recognized by staff during the testing process. This is a prime opportunity for staff education and creates a continued need for maintaining staff competency on a periodic, or at least annual, basis. The large number of staff involved in POCT creates an even greater chance for variability. Manual and labor-intensive methodologies do not prompt staff from one step to the next step, allowing for procedural errors and the opportunity to take short-cuts. Although laboratory professionals consider POCT devices to include glucose, pregnancy, rapid strep, and other ‘‘diagnostic’’ tests, physicians and clinical staff are more familiar with medical devices, such as scales and thermometers, that they consider POCT devices. The major differences among scales, thermometers, and glucose meters are that staff has fewer steps and decision making involved with medical devices. The pa- tient stands on a scale, and the physician assumes that the device gives the correct weight. Staff may need to zero the scale periodically, but the physi- cian does not need to check expiration dates, monitor refrigerator tempera- tures, check lot numbers and calibration codes, analyze quality control specimens, determine whether quality control is successful, and troubleshoot if quality control is not successful before obtaining a patient result. These several actions may seem inconsequential to a laboratory-trained individual, but are not routine at all for a clinician. These activities actually remove the clinician from his/her primary responsibility of patient care. Automation can reduce the potential for error. Devices that decrease the number of steps required to obtain a test result, prompt operators, or reduce the staff decision-making process can reduce the potential for mistakes. Newer POCT devices are computerized with electronic data capture that is capable of storing and transmitting results automatically to laboratory and hospital information systems. These devices can capture the date, time, operator identification, patient identification, meter serial number, and test lot number/expiration dates with every patient test result and store it in relation to the quality control performed on that device. Computerized devices can store a list of trained operators and request operator identifica- tion before allowing patient testing. If the identified operator is not on the authorized list, the device prevents untrained individuals from performing patient testing. Computerized devices also can require the analysis of two levels of quality control every 24 hours. The device compares quality control results against the expected target ranges and can interpret whether control results are successful or unsuccessful. These features assist with regulatory compliance by ensuring result documentation, performance of testing by trained operators, and daily quality control; however, these features also help staff to perform testing by prompting staff with each step of the analysis and by interpreting quality control results and taking appropriate action
  10. 10. 902 NICHOLS (allowing patient testing if successful and lock-up preventing patient testing and requiring repeat control analysis if unsuccessful). Automation of POCT devices also can help with data entry. Manual in- put of multiple numbers for operator and patient identification presents an opportunity for transcriptional errors. Computerized POCT devices have barcode readers that allow automated reading of operator barcodes and pa- tient barcoded wristbands. Barcoded data significantly reduce manual data entry errors in institutions implementing these systems [11]. Barcodes also have the potential to assist with positive patient identification if the device can provide a confirmation of the patient’s name after scanning the identi- fication number; however, few current POCT devices have the memory or wireless connectivity to offer this advanced positive patient identification, and this certainly is a feature to watch for in the next generation of devices. Training with ongoing competency checks is fundamental to ensuring quality test results. Staff operators of POCT devices should receive training specific to the device being used. Familiarization of test technologies in nurs- ing or medical school does not substitute for in-depth training on the method intended to be used for patient care. A CAP Q-Probes survey of hospital blood glucose programs that demonstrated the most significant levels of continued improvement over time focused on operator training [12]. These programs used standardized training materials, such as video- tapes, as part of the training and repeated training and review of perfor- mance at scheduled intervals. These programs also compared results regularly between point of care devices and central clinical laboratory test- ing and used computerized data capture in POCT devices to manage control and patient data [12]. In summary, POCT is dependent upon operator technique. Training and ongoing verification of competency are important. Current CAP and Joint Commission regulations require ongoing competency by observation of technique, written examination, analysis of quality control or specimens with known values, demonstration of maintenance, recording of test results, and evaluation of problem-solving skills. These skills should be checked initially, at 6 months, and annually after training. Use of devices with automated data management features can assist staff in appropriate test performance and help with regulatory compliance. Integration and communication POCT is not an isolated process and should be integrated with patient care pathways. The laboratory is blamed often for delays in patient manage- ment, particularly in the emergency room, preoperative and procedural areas of the hospital, and outpatient settings that are remote from a core laboratory. POCT is seen as one means of obtaining faster test results and reducing patient bottlenecks in the system. Unfortunately, just providing
  11. 11. POINT OF CARE TESTING 903 a faster test result does not guarantee improved patient outcomes. Manage- ment pathways also must change to better use the faster result. Consider point of care glucose testing where the physician has created a standing or- der for testing every hour but then leaves the nursing unit to attend to other patients. The advantages of obtaining a faster result are lost if the staff must look for a physician to take clinical action. If staff had a management pro- tocol available, they could take action immediately upon receipt of the test result by altering insulin dosage or administering food or intravenous glucose. The link of POCT with patient outcome was examined in a study con- ducted in the cardiovascular/radiology setting [13]. Patients were requested to arrive 2 hours before procedure for preparation; however, despite arriv- ing early, procedures frequently were delayed because laboratory results were unavailable. These delays resulted in open operating rooms, changes in physician scheduling, and stress and dissatisfaction for staff and patients, with the laboratory being blamed. Before a procedure, patients required cre- atinine and electrolytes to allow dosing of radiologic dyes, and coagulation testing was required to assess for postprocedure bleeding tendency after re- moval of indwelling catheters after the procedure. POCT was seen as the optimal solution; however, implementation of POCT did not result in the expected improvement in outcome (ie, meeting scheduled procedure time). Improvement was noted only after changes were made in the overall procedure scheduling and management. Intercom systems that communicated between staff in the procedure rooms and staff preparing patients allowed for better timing and preparation of patients with rooms that were becoming available. POCT was only one of many steps that needed to be accomplished before a procedure could be started. A delay in any step could lead to delays in the final outcome, meeting the scheduled procedure time. Once the patient preparation management path- way was streamlined, significant improvements in meeting scheduled proce- dure times were accomplished [13]. Therefore, implementation of POCT must be linked to changes in patient management to improve outcomes. The cardiovascular/radiology example illustrates that laboratory testing is only one component of a complex path- way of care that ultimately leads to the patient outcome. Improvement in one step of the pathway does not guarantee improved outcome without con- sidering all of the other aspects of care, and, in this case, other sources for delays. Communication is fundamental to achieving the desired improvements. All staff needs to understand the total pathway to relate their individual role within that pathway of care. Unfortunately, physicians and laborator- ians have different understandings of the role of POCT in the patient care pathway. Physicians view POCT as the same test as core laboratory methods, only faster, whereas laboratorians understand that POCT is a dif- ferent methodology, with inherent precision and accuracy biases and unique
  12. 12. 904 NICHOLS limitations. Both perspectives are required in the development of patient care pathways and optimizing the delivery of patient outcomes. Although physicians simply may want to use their same treatment cutoffs and guidelines between core laboratory and POCT technologies, laborator- ians understand that these treatment protocols may need to be modified based on the technical performance of the POCT method selected and its agreement with the core laboratory. As an example, POCT creatinine was im- plemented in a hematology/oncology clinic to allow more rapid dosing of che- motherapy and reduce patient wait times [14]; however, despite the POCT and core laboratory using the same creatinase (enzymatic method), the POCT method categorized more patients as having abnormal renal function compared with the core laboratory. This would have resulted in significantly different dosages of chemotherapy in the same patient depending on whether POCT or core laboratory results were used. Ultimately, the pharmacy had to change the management cutoffs based on the test method to ensure compara- ble dosing between the core laboratory and POCT methods [14]. These test differences indicate the need to clearly communicate and dis- tinguish the methodology of the test with the result. It is not sufficient to write a ‘‘creatinine’’ result in the patient’s chart without distinguishing whether the result was ‘‘POCT creatinine’’ or ‘‘core laboratory creatinine.’’ The adoption of electronic medical records emphasizes even more the need to consider unique test methodologies when fields are established in the medical record. Electronic records have the ability to be distributed and ac- cessed widely in a health system, with staff adding test results from the core laboratorydas well as physician office practices, inpatient POCT, and home nursingdto the same record. Test results can be separated by name (eg, POCT glucose, laboratory glucose, blood gas glucose); however, CLIA reg- ulations also require the location and laboratory director of the test to be linked to the final test result. Because locations with different addresses can have unique CLIA certificates, a patient’s medical record in a large in- stitution easily could have dozens of different test names (eg, inpatient POCT glucose, laboratory glucose, Dr. Smith’s glucose, Dr. Jones’ glucose, Dr. Miller’s glucose). Because this could be confusing to the physician interpreting the test, some institutions have simplified the complexity of this problem by separat- ing testing into two test fields: POCT and core laboratory methods. Core laboratory methods generally are resulted through an instrument interface from a laboratory information system and automatically tagged with the laboratory director and appropriate CLIA certificate. POCT results, how- ever, can be entered electronically or manually. Electronic entry can be han- dled the same as laboratory test results by automatically linking the appropriate CLIA-required information. Manual data entry necessitates the staff to remember to enter the appropriate information with every test result. This task can be simplified by just requiring staff to select their loca- tion from a dropdown screen before a test can be resulted (Fig. 2). This
  13. 13. POINT OF CARE TESTING 905 Fig. 2. Sample POCT result form for pH test reporting to a patient electronic medical record. POCT result form contains fields for selecting positive or negative results from amniotic fluid pH (with appropriate reference intervals) or free text fields for reporting numerical results and comments. This POCT form requires selection of the site location linked to the site’s CLIA certificate (Organization/CLIA#) before results can be verified and reported to the pa- tient medical record. Staff enter the test result with any comments in the appropriate field, and select the testing location from the dropdown menu to attach the appropriate CLIA certif- icate to the POCT result. The patient’s electronic record will display only the test result; by right-clicking the mouse, staff can view associated comments and test location/CLIA certificate information required for regulatory compliance. dropdown screen is linked electronically to the required information, cur- rent CLIA certificate, and director and ensures that every test captures the necessary information to interpret the test result and meet regulatory compliance. By setting up the system to require the location with every re- sult, staff is automatically prompted and cannot complete the task without the necessary location information. Clinical pathways and management protocols are a good means of assist- ing physician interpretation and bridging the laboratory–clinical communi- cation gap. Resources are available to assist the development of clinical practices and pathways of care. The National Academy of Clinical Bio- chemistry (NACB) has conducted a systematic review of the scientific liter- ature linking POCT to patient outcome and published Laboratory Medicine Practice Guidelines titled ‘‘Evidence-based practice for POCT’’ [15] (avail- able at www.nacb.org). These peer-reviewed guidelines represent a consensus of best practices from the literature. Use of these guidelines helped to revise a chest pain pathway for the man- agement of patients in the emergency department (Table 1). Before revision,
  14. 14. 906 NICHOLS Table 1 Laboratory testing performed as part of an emergency department chest pain care pathway. Testing has been streamlined and relies on the cardiac-specific troponin marker over creatinine kinase. Revision of this pathway defines a 6-hour end point for patient disposition and de- creases the number of phlebotomies and amount of blood 2001 2004 At presentation (hour 0) At presentation (hour 0) Stat troponin Stat troponin CK (reflex CK-MB) Automated complete blood cell count Automated complete blood cell count Chemistry panel Chemistry panel Electrolytes Electrolytes Serum urea nitrogen Serum urea nitrogen Glucose Glucose Serum hold tube Hour 3 CK (reflex CK-MB) Hour 6 Stat troponin qualitative (POCT) Lipid panel (or fasting preferred) Hour 9 Troponin CK (reflex CKMB) Repeat every 3–6 hours until discharge Discharge or admission Lipid panel (or fasting preferred) patients with chest pain would receive ECG, physical, and laboratory testing on presentation to the emergency department for glucose, electrolytes, cell counts, urea nitrogen, and creatinine. Cardiac marker testing included initial total creatinine kinase (CK) and cardiac-specific muscle/brain isoenzyme (MB) fraction if total was elevated plus troponin. Extra tubes of blood were collected and held in case additional testing was required. The total CK/CK-MB was repeated every 3 to 6 hours, with troponin added every 9 hours until the patient was admitted or discharged. After review of the NACB practice guidelines for cardiac markers published in 2002 in conjunc- tion with the American College of Cardiology [16], the chest pain pathway was streamlined so that the cardiac marker test consisted of just an initial qualitative POCT troponin followed at 6 hours with a quantitative troponin test. The revised protocol defined admission if any of the diagnostic tests were positive (ECG or laboratory) and an end point for discharge at 6 hours for two negative ECGs, two negative troponins, and a negative stress test. The qualitative POCT provided a fast, initial result that the clinicians could use to manage the patient rapidly on presentation to the emergency room, followed by a more definitive laboratory troponin at 6 hours to decide on discharge. Less blood was collected from patients, and fewer tests were con- ducted (eliminated reliance on multiple timepoints of CK/CK-MB). This pathway also assisted physicians in ordering the right test (POCT versus
  15. 15. POINT OF CARE TESTING 907 laboratory testing) at the right time in the patient’s care (admission versus 6 hours postadmission) and standardized clinical management, thereby reduc- ing practice variation. By embedding this pathway into an electronic order- ing system, test ordering can be standardized for patients with the same diagnosis. This pathway improves consistency of care and enhances commu- nication between the clinician and the laboratory, because the physician knows when to order the right test for the patient and the laboratory now knows why a test is being ordered and can relate the test back to the point in a pathway of care for that patient. Recent revisions of the NACB cardiac guidelines relating to POCT are included in the recent ‘‘Evidence-based practice for POCT’’ guidelines, and all of the published NACB practice guidelines are available through links from the National Guideline Clearing- house at Agency for Healthcare Research and Quality (AHRQ) (www. guideline.gov). Summary POCT offers the potential for fast test results and more rapid patient treatment; however, concerns over the quality of test results and difficulties in managing the documentation from multiple sites, operators, and devices have created challenges to the widespread adoption of POCT. Practical management of POCT requires an organizational structure with defined staff roles in the supervision of testing and day-to-day operation. There are multiple sources of potential error in POCT, including environmental and operator factors. Development of an overall quality assurance program for POCT should consider the entire preanalytic, analytic, and postanalytic phases and use computerized device features to automate manual steps, sim- plify the testing process, and reduce necessary decision making. POCT is a different methodology from core laboratory testing, and the laboratory needs to establish effective channels of communication with the physician to distinguish test results, highlight test limitations, and assist with result in- terpretation. Pathways of care and management protocols help with com- munication and standardize practice. Resources are available through the NACB Laboratory Medicine Practice Guidelines and National Guideline Clearinghouse to help use POCT in the most effective manner for improving patient outcome. References [1] Stephens EJ. Developing open standards for connectivity. In Vitro Diagnostics Technology 1999;5(9):22–5. [2] Cambridge Consultants. POCT diagnostic market report. Cambridge (UK): 2006. [3] Department of Health and Human Services, Health Care Finance Administration. Clinical laboratory improvement amendments of 1988, final rule. Fed Regist 1992;7001–288. [4] Howerton D, Anderson N, Bosse D, et al. Good laboratory practices for waived testing sites: survey findings from testing sites holding a certificate of waiver under the clinical laboratory
  16. 16. 908 NICHOLS improvement amendments of 1988 and recommendations for promoting quality testing. MMWR Recomm Rep 2005;54(RR-13):1–22. [5] Greyson J. Quality control in patient self-monitoring of blood glucose. Diabetes Care 1993; 16:1306–8. [6] Meadows S, Kubic M. Improving glucose monitoring for diabetics. FDA Consum 1990;32–5. [7] Kocka FE, Roemisch E, Causey WA, et al. The urinometer as a reservoir of infectious organisms. Am J Clin Pathol 1977;67:106–7. [8] Acolet D, Ahmet Z, Houang E, et al. Enterobacter cloacae in a neonatal intensive care unit: account of an outbreak and its relationship to the use of third generation cephalosporins. J Hosp Infect 1994;28:273–86. [9] Webb R, Currier M, Weir J, et al. Transmission of hepatitis B virus among patients under- going blood glucose monitoring in long-term care facilities–Mississippi, North Carolina and Los Angeles County, California, 2003–2004. MMWR Morb Mortal Wkly Rep 2005;54(9): 220–3. [10] Bonini P, Plebani M, Ceriotti F, et al. Errors in laboratory medicine. Clin Chem 2002;48(5): 691–8. [11] Nichols JH, Bartholomew C, Brunton M, et al. Reducing medical errors through barcoding at the point of care. Clin Leadersh Manag Rev 2004;18(6):328–34. [12] Jones BA, Howanitz PJ. Bedside glucose monitoring quality control practices: a College of American Pathologists Q-probes study of program quality control, documentation, pro- gram characteristics, and accuracy performance in 544 institutions. Arch Pathol Lab Med 1996;120:339–45. [13] Nichols JH, Kickler TS, Dyer KL, et al. Clinical outcomes of point-of-care testing in the interventional radiology and invasive cardiology setting. Clin Chem 2000;46(4):543–50. [14] Nichols JH, Bartholomew C, Bonzagi A, et al. Evaluation of the IRMA TRUpoint and i-STAT creatinine assays. Clin Chim Acta 2007;377(1–2):201–5. [15] Nichols JH, Christenson RH, Clarke W, et al. Evidence-based practice for point-of-care test- ing: a NACB laboratory medicine practice guideline. Clin Chim Acta 2007;379:14–28. [16] Wu AHB, Apple FS, Gibler WB, et al. National Academy of Clinical Biochemistry Stan- dards of Laboratory Practice: recommendations for the use of cardiac markers in coronary artery diseases. Clin Chem 1999;45(7):1104–21.