CAP TODAY Pathology/Laboratory Medicine/Laboratory Management
CAP Publications released this month its newest book, Quality Management in Clinical Laboratories: Optimizing Patient Care Through Continuous Quality Improvement. It is a second edition; the first was published in 2005. Twenty-one contributors cover everything from laboratory staff and informatics to all phases of testing and the laboratory quality management plan. On this page and page 40 is part of the chapter on the clinical microbiology laboratory.
Here is what the book’s editor, Richard Brown, MD, told CAP TODAY’s editor about the new edition. Dr. Brown is medical director of system laboratory services at Memorial Hermann Health System in Houston and chair of the CAP Quality Practices Committee.
April 2024—This is a second edition and the first was published almost two decades ago. I would think most of the chapters were revised extensively and others are entirely new. Paul Valenstein, MD, editor of the first edition, writes in the preface that the second edition is a better book. Can you tell us a little about this second edition—in particular about the topics it covers, the contributors, and how it differs from the first?
The second edition of the quality management manual differs considerably from the first edition, which was written masterfully by Dr. Paul Valenstein, with contributions from members of the Quality Practices and Patient Safety committees. The current members of the Quality Practices Committee, in deciding to write the second edition, opted to have multiple committee members write separate chapters on specific laboratory quality management topics, each in their own areas of expertise. As the committee members developed their chapters they enlisted the help of additional colleagues who are experts in their particular area.
Topics include continuous quality improvement, tools for implementation, and a history of the concept; regulatory issues; challenges in the preanalytical, analytical, and postanalytical phases of the test cycles; the quality management plan; the role of informatics in quality management; and the importance of the pathologist in communicating laboratory quality beyond the laboratory. The chapter published in part in this issue of CAP TODAY, on quality management in the clinical microbiology laboratory, was added because this topic has rarely been discussed in detail and the quality issues relevant to microbiology are in many ways different from those in the core laboratory. In contrast to the first edition, we did not include extensive discussions of transfusion medicine and anatomic pathology because these topics are so effectively covered in publications from the AABB and in the CAP Quality Management in Anatomic Pathology manual, respectively.
Who is the targeted audience for this book and is there anything similar on the market?
This book is intended for pathologists, particularly those new in practice, pathology residents, and clinical laboratory scientists who may be called upon to become a laboratory director or assist with laboratory director responsibilities. It is very much a hands-on, how-to guide containing practical tips from the authors’ practices, such as how to troubleshoot quality control failures and perform carryover studies and lot-to-lot comparisons, as well as samples of interpretive comments that can be used for reporting complex coagulation studies and numerous ideas for quality metrics encompassing various areas of the laboratory. In the diversity of topics covered and the practicality of the content, I believe this is a book unlike anything currently on the market.
Dr. Valenstein said pearls can be found throughout the book. Can you give us one example?
In addition to the pearls listed above, two highlights of this book include appendices containing a complete guide to specimen collection, suitable for distribution to potential phlebotomists, and a detailed example of a quality management plan.
What in your experience as a medical director of laboratory services and chair of the CAP Quality Practices Committee is the most difficult part of quality management in clinical labs? That is, what is most difficult for most people about quality management, or does it vary too much from laboratory to laboratory to name just one or two things?
I believe that laboratories struggle most with where to begin, and in finding the resources of staff time and expertise, when designing a quality improvement project, performing verification/validation studies, and designing an effective quality management system. This is exactly why, in this edition of the book, we focused on providing practical examples.
Here, from the new book, are two sections (minus references) of the chapter on quality management in the clinical microbiology laboratory, by Gary W. Procop, MD, MS, and Ronald B. Schifman, MD. The full chapter covers not only wound and respiratory cultures and cultures for fungi and mycobacteria (shown here), but also blood and urine cultures, antimicrobial susceptibility testing, and stool cultures, antigen tests, and molecular assays for stool pathogens. In their introduction to the chapter, Drs. Procop and Schifman write: “This chapter is not inclusive of all the quality initiatives that should be undertaken in clinical microbiology, but rather is a review of some of the most important topics and considerations.”
To order the new quality management book, call 800-323-4040 option 1 and request PUB319 or order online at www.cap.org (Shop tab). The book is $96 for CAP members and $120 for nonmembers.
Wound and Respiratory Cultures
Principle/Introduction
There are several quality performance considerations for wound and respiratory cultures. These have been included together since these specimen types often include a Gram stain that, as for the blood culture specimens described above, is performed and reported prior to culture. This provides another opportunity for Gram stain-to-culture correlation. Guidance should be given to providers regarding the highest yield specimen types and the evidence-based rejection criteria that will be used. Institution of specimen quality parameters will translate into an improvement in the quality of results from these specimen types.
Quality Indicators
Preanalytical. The preanalytical phase of both wound and respiratory cultures is critical for obtaining optimal results. One of the most widely used quality parameters employed prior to culturing a respiratory specimen, particularly a sputum specimen, is the assessment of the specimen for excessive squamous epithelial cells (i.e., > 10 squamous epithelial cells per low power field). Similar criteria have been applied to other related specimen types, such as endotracheal aspirates. The criterion of “no organisms seen” has also been used for the rejection of specimens as inadequate for bacterial culture, but it is not as commonly used as the assessment for excessive squamous epithelial cells.
Cultures of specimens with excessive squamous epithelial cells, which represents oral contamination, will yield oropharyngeal microbiota (i.e., oral flora). This may include organisms that could represent pathogens in another setting (i.e., from a normally sterile site or a high-quality respiratory specimen), such as H. influenzae, S. pneumoniae, and M. catarrhalis, amongst others. If rejection criteria are not used, the subsequent work-up of normal microbiota will impart significance to these isolates, which may mislead the physician, delay the discovery of the true pathogen (e.g., Legionella), and result in unnecessary antibiotic therapy. Otherwise stated, the work-up of respiratory specimens that should be rejected significantly decreases the positive predictive value of the test result and may cause patient harm.
There is extensive literature concerning the Gram stain assessment of wound specimens for culture, but it is not as uniformly employed as in the screening of respiratory specimens. Laboratory directors are encouraged to review this literature and form a local working group with representation from microbiology, surgery, and infectious disease to determine how these specimens will optimally be processed and interpreted for the local patient population. However, it should be stressed that regardless of the setting, surface culture of wounds, particularly long-standing wounds, will do little to demonstrate the pathogen that may be causing the associated cellulitis. Similar to the work-up of unacceptable respiratory specimens, the colonizing surface microbiota may be mistaken for the pathogens, and therapy could be erroneously directed toward them.
Analytical. The Gram stain, like other direct examinations (e.g., intraoperative consultation), provides rapid information to the attending physician that can be immediately used to direct therapy. The presence of abundant lancet-shaped, gram-positive diplococci in a high-quality respiratory specimen would be indicative of a pneumococcal pneumonia toward which the physician could direct therapy. The correlation of the Gram stain findings with the final wound or respiratory culture results provides an excellent quality assessment of the individuals performing and interpreting the Gram stain. In addition to identifying gaps in performance, the real-time correlation may facilitate optimization of patient care. For example, if beaded, gram-positive bacilli are present, then an acid-fast stain should be performed and a mycobacterial culture ordered, if these have not already been performed. One can imagine similar scenarios in medical mycology, if hyphae were seen, or for parasitology, if the larvae of Strongyloides were detected in a respiratory Gram stain. The engagement in these types of quality practices improves laboratory practice and clinical care.
The criteria for interpretation of cultures should be determined by the laboratory director and should be clearly described in the procedure manuals. This usually takes into consideration the amount and type of microorganism present in the culture. Interpretation should avoid the unnecessary work-up of small quantities of microbiota that likely represent contamination or colonization. Examples would include minute quantities of normal respiratory microbiota in respiratory specimens and skin microbiota in wound specimens. There should be an opportunity to make site specific exceptions. For example, whereas Corynebacteria are often part of the normal skin microbiota, these are the pathogens in patients with cystic neutrophilic granulomatous mastitis; therefore, Corynebacteria from breast biopsy specimens should be handled differently than isolated from other specimen types.
Postanalytical. The reporting of only pathogens and potential pathogens from these specimen types is important to prevent the overuse of antibiotics, which contributes to the spread of antimicrobial resistance. Pathologists and clinical microbiologists should provide consultative services for individuals who have questions regarding the work-up of these cultures or the reporting of susceptibility results, which contributes to the quality use of culture results.
Cultures for Fungi and Mycobacteria
Principle/Introduction
The pathophysiology of infections by fungi and mycobacteria varies by species. This is important to understand so that the appropriate specimen may be collected and optimal culture technique applied. These tests use unique direct examination techniques (i.e., KOH/Calcofluor white and acid-fast staining) and culture methods that require thorough consideration by experts in these subspecialties to assure the highest quality of test results.
Quality Indicators
Preanalytical. Microorganisms in these groups that cause bloodstream infections, such as Candida species and some rapidly growing mycobacteria, are often recovered from routine blood cultures, whereas others (e.g., Histoplasma capsulatum and other mycobacteria) are better detected using alternative methods (e.g., lysis centrifugation blood cultures). Swabs are only an acceptable specimen collection method for the detection of yeasts from a mucosal surface (e.g., thrush or vulvovaginal candidiasis). Swabs should be rejected from deep-seated lesions (i.e., tissue specimens) that are suspected to be caused by mycobacteria or filamentous fungi as these specimens are associated with a substantial false-negative rate. Tissue is needed for the recovery of these microorganisms from deeper sites. This is because these microorganisms are either invasive into the tissue (e.g., hyalohyphomycosis) or are encased within a granuloma (e.g., tuberculosis). Swabs are ineffective in dislodging the microorganisms from the tissue and the inflammatory response in these settings. Higher yields are achieved through excision and culturing of infected tissue.
Analytical. A review of standard methods for operating a high-quality mycology and mycobacteriology laboratory is beyond the scope of this chapter. Important quality considerations concern direct examination and other rapid tests, culture techniques, and methods of identification and susceptibility testing.
A direct examination of clinical specimens is important for the detection of fungal and mycobacterial infection. These, like the Gram stain, are rapid and provide information that may significantly guide therapy. Foremost, the detection of fungal elements or acid-fast bacilli denotes an infection caused by microorganisms within these groups, rather than more commonly encountered bacterial pathogens. The turnaround time for these direct examinations, as well as the direct exam-to-culture correlation, should also be performed for these tests.
Special considerations in mycology include ensuring plates do not dry out because of extended incubation (e.g., using deep poured plates and a humidified incubator). Special considerations in mycobacteriology include monitoring M. gordonae recovery rates to assure that over-decontamination of specimens is not occurring. The use of both solid and liquid media for the recovery of mycobacteria is the standard of practice.
Records of competency assessment for personnel that use unique techniques in these areas must also be maintained. Standard quality assurance measures and controls should be used to assess media, test platforms (e.g., MALDI-ToF), and susceptibility tests.
Postanalytical. Like the Gram stain, the direct examinations used in mycology and mycobacteriology are important for directing therapy. Therefore, quality metrics should be considered regarding the turnaround time for these results, as well as the accuracy. Selective comments should be considered (here and elsewhere) for microorganisms that may represent contaminants rather than true pathogens (e.g., M. gordonae) and for organisms with innate resistance to certain classes of antimicrobial agents (e.g., Cryptococcus species are innately resistant to all echinocandins).