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CLSI Blog Articles

Read the latest articles about CLSI and laboratory standards in the official CLSI Blog. Browse our most recent blog articles below.

Using Proficiency Testing to Improve Medical Laboratory Quality

Proficiency testing (PT) is a valuable tool in the quality improvement process. PT provides one measure of objective evidence of laboratory competence to customers and regulatory and accreditation organizations. It serves as a unique source of information not obtainable by other methods. Current accreditation requirements include integration of PT into the laboratory’s quality improvement program.

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Manage Nonconforming Events in the Lab With a Quality Management System

Nonconforming events in the laboratory can be reduced by implementing an effective quality management system (QMS). A laboratory QMS is a systematic, integrated set of activities to establish and control the work processes from preanalytical through postanalytical processes, manage resources, conduct evaluations, and make continual improvements to ensure consistent quality results.1 All aspects of the laboratory operation need to be included in a QMS.

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Order of Blood Draw Tubes and Additives

Blood samples must be drawn by phlebotomists in a specific order to avoid cross-contamination of the sample by additives found in different collection tubes. Phlebotomy order of draw is the same for specimens collected by syringe, tube holder, or into tubes preevacuated at the time of collection.

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Chloride Sweat Testing for Cystic Fibrosis

Chloride sweat testing is used to help diagnose cystic fibrosis (CF), an inherited disorder that disrupts the normal function of epithelial cells found in the sweat glands and lining of passageways in the lungs, liver, pancreas, and digestive and reproductive systems. According to the Cystic Fibrosis Foundation, the sweat test is considered the gold standard for diagnosing cystic fibrosis. Sweat testing should be done at a CF Foundation-accredited care center.

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Patient Safety Through Process Management

The Joint Commission’s 2019 National Patient Safety Goals for laboratory services is a patient safety guideline that sets goals the laboratory must achieve to satisfy accreditation requirements.

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The Cefazolin Inoculum Effect for MSSA

Infections due to methicillin-sensitive Staphylococcus aureus (MSSA) continue to be a significant source of morbidity and mortality. While antistaphylococcal penicillins, such as nafcillin, have been the mainstay of therapy for MSSA, the use of cefazolin has grown increasingly popular. Indeed, recent data from observational clinical studies suggest that cefazolin is as efficacious as nafcillin, with less toxicity, has a more favorable dosing schedule, and possibly improves survival. Thus, cefazolin has become first line therapy for the treatment of MSSA infections.

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Differences in Disk Content Recommended by CLSI and EUCAST for Disk Diffusion Testing

Disk diffusion testing is used by a variety of laboratories throughout the world. Disk diffusion breakpoints are dependent on the concentration of antimicrobial impregnated into the disk, otherwise known as the disk content. This disk content in microgram concentrations is printed on each disk and is listed in both CLSI’s M100 and M45 and European Committee on Antimicrobial Susceptibility Testing (EUCAST ) breakpoint tables.

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CLSI's Guidelines on Clinical Method Validation & Verification

Interferents in medical laboratory measurement pose a danger to patients. Although performance is routinely monitored by internal QC and external quality assessment procedures, laboratories cannot easily detect error caused by interferents. Therefore, manufacturers of in vitro diagnostic measuring systems need to include evaluation of potential interferents’ effects in their risk analyses at the product design stage.

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