Specimen Identification

In many laboratory information systems, electronic entry either in the laboratory or at a nursing station of a test order for a uniquely identified patient generates a specimen label bearing a unique laboratory accession number. A record is established that remains incomplete until a result (or set of results) is entered into the computer against the accession number. The unique label is affixed to the specimen collection container when the blood is drawn. Proper alignment of the label on the collection container is critical for subsequent specimen processing when using bar coded labels. Arrival of the specimen in the laboratory is recorded by a manual or computerized log-in procedure. In other systems, the specimen is labeled at the patient s bedside with the patient identification and collection information and enters 

For analyzers that do not automatically link specimen identity and aspiration, the sequence of results produced must be linked manually with the sequence of entry of specimens. Some analyzers print out or transmit to a host computer each result or set of results from a specimen, either by position of the specimen in the loading zone or by the accession number programmed to that position. 

A major advance in the automation of specimen identification in the clinical laboratory has been the incorporation of bar coding technology into analytical systems.In practice, a bar coded label (often generated by the laboratory information system and bearing the specimen accession number) is placed onto the specimen container and is subsequently read by one or more bar code readers that have been strategically placed at key positions in the analytical train. The resultant identifying and ancillary information is then transferred to and processed by the system software. 

Initiating bar code identification at a patient s bedside ensures greater integrity of the specimen s identity in an ana- 

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The specimen is accessioned manually in the non-gynecologic specimen logbook a consecutive number is assigned to the specimen container, requisition, slides, and 50 mL-centrifuge tube. In addition, every container and slide is labeled with patient s name. Non-gynecologic specimen identification number starts with prefix CY. ... 

In addition, every container and slide is labeled with patient s name. Non-gynecologic specimen identification number starts with prefix CY. ... 

The importance of a comprehensive specimen identification system throughout the clinical laboratory cannot be understated. Both the College of American Pathologists (CAP) (1) and The Joint Commission (JCAHO) (2) have addressed this important subject with directives that address the pre-analytical, analytical and post-analytical phases of specimen processing. These patient safety initiatives date back to the 1990 s and the formation of the National Patient Safety Foundation (3). These mandates have become the backbone of most laboratories Quality and Safety Programs and offer an excellent foundation for procedures that assure the safe and accurate identification of patient specimens throughout the analysis and reporting of critical laboratory tests. 

It is critical that correct specimen identification is maintained at every step of laboratory testing process including all pre-analytical, analytical and post-analytical stage of testing. Labels to be used for... 

Have clear and concise procedures based on CAP and JCAHO specimen identification recommendations... 

Backstrom JR, Miller CA, Tokes ZA (1992) Characterization of neutral proteinases from Alzheimer-affected and control brain specimens identification of calcium-dependent metal-loproteinases from the hippocampus. J Neurochem 58 983-992 Basun H, Forssell LG, Wetterberg L, Winblad B (1991) Metals and trace elements in plasma and cerebrospinal fluid in normal aging and Alzheimer s disease. J Neural Transm Park Dis Dement Sect 3 231-258... 

Establish written policies and procedures for rapid specimen identification and electronic reporting of results. 

Specimen identification The sample must not be dispatched until it has been labelled correctly and the appropriate form for specimen identification has been enclosed. Mistakes made during identification (mismatching of names or samples) can be the source of considerable misjudgements or delays and may also cause grave errors with possible legal consequences. 

Specimen identification and test ordering errors occur frequently in the clinical laboratory and emanate from errors... 

Integrated computers can in turn communicate with mainframe computers. A typical interface implemented in computers is a UART (universal asynchronous receiver and transmitter), which is in turn connected to an RS-232, RS-488, or Ethernet interface to permit interactive communication with other computer systems. The same interface capability permits transmission by modem (modulator-demodulator) over telephone lines. The telephone line may allow the manufacturer s central service department to enhance the ability of the on-site operator to service and repair the analyzer. With a bidirectional interface, it is possible to download from the main LIS computer such data as specimen identification, which governs specimen location in the analyzer s loading zone, and to send test results from the analyzer back to the LIS, either in real time or by batch. 

Computers incorporated into instruments or connected through stand-alone PCs have expanded the capabilities of instrument systems to include those previously available only by connection to the mainframes of LISs. These capabilities include summaries of quality control (production of Shewhart plots), fitting of immunoassay calibration curves using various models (e.g., four parameter log-logistic), and linkage of patient information with specimen identification. 

The NCCLS has an Area Committee on Automation and Informatics, which oversees the above standards and initiates new standards development projects. Current standards development projects include Data Content for Specimen Identification, Protocols to Vafidate Laboratory Information Systems, and Remote Access to Hospital Diagnostic Devices via tihe internet. In 2002, ASTM transferred to NCCLS the ownership and copyright of aU nine standards in its E31.13 group, including the two standards referenced above. These standards all relate to the clinical laboratory, with some of them simply preceding or overlapping the NCCLS automation standards. NCCLS is now in the process of evaluating which of these standards will be maintained and updated and which may be abandoned. 

Whisler K, Maffetone M> Watt S. Automated system for positive specimen identification and sample handling. Clin Chem 1990 36 1587-8. 

The principles and concepts of TQM have been formalized into a quality management process, as illustrated in Figure 19-3. The traditional framework for managing quality in a healthcare laboratory has emphasized the establishment of quality laboratory processes (QLPs), QC, and quality assessment (QA). A QLP includes analytical processes and the general poHcies, practices, and procedures that define how all aspects of the work get done. QC emphasizes statistical control procedures but also includes nonstatistical check procedures, such as linearity checks, reagent and standard checks, and temperature monitors. QA, as currently applied, is primarily concerned with broader measures and monitors of laboratory performance, such as turnaround time, specimen identification, patient identification, and test utility. Quality assessment is the proper name for diese activities rather than quality assurance. Measuring performance does not by itself improve performance and often does not detect problems in time to prevent harmful effects. Quality... 

Certain errors, particularly errors in specimen identification, have been detected by comparing laboratory test results with values obtained on previous specimens from the same patient. The expected variability of test results depends on both tlie analyte and the time interval between determinations. Ladenson has defined delta check limits based on a 3-day mterval in terms of a percentage change from the initial value. His check limits for some common tests are shown in Table 19-6. 

Identification is a major problem in clinical laboratories, and serious untoward events can occur with misidentified specimens. Unambiguous identification is possible today with bar-coding and similar machine-labeling techniques (31). The model discussed here is for testing patient-derived materials in a clinical laboratory the model can, of course, be extended to other applications. A machine-readable label on every specimen is the contemporary standard of modern equipment. Keying in identifiers to an instrument is less desirable owing to the inevitable human errors. In our experience with bar-code readers, they read the label correctly or don t work at all. The topic, automated specimen identifications, is described in more detail in Section 8.2 here (32). 

Sampling Selection of materials and specimens, identification of population, selection of method/ sampling model, sample number/mass/size, sampling plan, collection techniques, compilation of logistics, preparation of tools, timing, meaningful and representative collection, minimization of contamination and analyte losses (here and in all other steps), conservation of spedation... 

The specimen is received into the laboratory along with a completed requisition indicating the specimen identification, number of cassettes, researcher name, department, account, telephone extension, procedures to be performed on the specimen, and any additional pertinent information. The requisition is logged into the proper log book (research or patient) and given a laboratory number for identification. Then the cassettes are placed on the automatic processor (overnight or day run) to be dehydrated, cleared, and infiltrated with paraffin see Table 2). When the processor has finished, the cassettes are removed and placed in a paraffin bath to await embedding. The specimen is... 

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