Cover Story

Lab basics 202

By Anne Beall

Three issues plague the microbiology lab today:

• Staffing: "The U.S. Department of Health and Human Services reports that by 2012, 138,000 lab professionals will be needed, but fewer than 50,000 will be trained. Thirteen percent of the current laboratory staff is likely to retire in the next five years."¹ "There are two incoming clinical laboratory scientists for every seven retiring; 100,000 positions vacant by 2012."² The bottom line is that experienced microbiology technologists are hard to come by these days.
• Workload: Mandatory MRSA screening, increasing organism resistance requiring specialized testing (i.e., "D" test, Hodge test), and an increasing number of infections. Overall, these factors contribute to an escalating workload in microbiology.
• Demand: The microbiology department faces pressures from many areas within the organization: Administrators are cutting budgets; physicians are demanding results sooner; and government is telling administrators that it will be denying payment for healthcare-associated infections (HAIs).

How does the microbiology laboratory deal with such pressures? By taking three simple steps:

1. Ensure the laboratory is collecting, transporting, and plating specimens following basic microbiology principles. Just because it grows in culture does not always mean that there is a real infection process going on.
2. Perform tests that improve services, patient care, and therapeutic choices.
3. Utilize staffing resources efficiently; automate as much as possible; and develop processes that improve overall efficiency, reduce cost, and add value to patient care.

High-quality specimens lead to high-quality results and better patient care. Whether the laboratory is performing rapid antigen and/or polymerase chain reaction (PCR) testing; has access to automated plate streaker or automated antimicrobial susceptibility test (ID/AST) instruments; and/or has processes designed with high efficiency and less manual labor — the microbiology result will always be dependent on specimen collection, first and foremost.

Most microbiology laboratories have quality indicators that center on basic specimen collection. The age-old saying "garbage in garbage out" is the basis for good microbiology practice. Those who collect samples for the microbiology laboratory need to be monitored and given feedback regularly, so they become acutely aware of how they affect patient care. A poorly collected specimen can lead to many scenarios ranging from:

• false-negative cultures to inappropriate or unnecessary antibiotics given to patients (which lead to organism resistance), to
• treating patients for infections they do not have (as in the case of a contaminated blood culture) and extending their hospital stay.

With today’s emphasis on HAIs, specimen collection is even more important than ever before. "Do it right the first time" should be the mantra for microbiology labs; spend more time upfront ensuring that specimens processed in microbiology labs are quality specimens.

How can lab professionals ensure that the specimens received in the lab are high quality? Training nurses and phlebotomists on the proper technique for collecting blood cultures is warranted. Concentrating on specimen collection can save a laboratory and an institution thousands of dollars in costs associated with antibiotics, labor, and length of hospital stay. The blood culture contamination rate in a lab may be well below the 3% national benchmark; however, consider this simple exercise:

According to the article "Controlling blood culture contamination rates,"³ contaminated blood cultures costs an average of $5,000 per incident, and patients stay in the hospital an extra 4.5 days — and keep in mind that these are 2004 figures. If a lab performs 1,000 blood cultures per month, it is working up 360 bottles that are contaminated per year, costing the facility $1,800,000 per year at minimum. Also, patients are staying 1,320 additional days. Investing effort upfront in educating the staff can save a facility thousands of dollars.

Aside from blood-culture contamination, many microbiology laboratories have other monthly quality indicators such as contaminated urines, sputum quality, corrected report rates, and more. What do you do with this information? The premise for performing these quality indicators is to communicate back to nursing or the specimen collector how well they are performing collection practices, or to implement practices that would improve the quality indicators. Several actions can be taken to improve the quality of specimens. For example:

• Boric-acid urine collection tubes cut back on contamination of urine samples.
• There is no need for refrigeration; simply expedite transport to lab, especially if many of the samples come from outreach programs and nursing homes.

Another aspect to consider is collection methods that do not require additional allocation of specimens once in the lab. Frequently, nurses collect the specimen (i.e., urine, stool, body fluids). After that specimen is received in the lab, it might be allocated to different departments (e.g., urines split between urinalysis and microbiology) and/or different procedures (e.g., stools split for O&P, culture, and occult bloods). With the strong emphasis on LEAN/Sigma today, consider having a collection procedure that allows for collection, preservation, transportation, and allocation performed at the origin of the collection (i.e., by the nurse). Stool, urine, and sterile body fluids samples are perfect examples for these types of LEAN/Sigma collection practices, and many collection containers are available to support this practice.

Swab specimens present another debate. The swab was developed for the convenience of collecting certain types of specimens. A good microbiologist should remember that there are instances where using a swab to collect specimens is appropriate and, at times, the only choice (i.e., throat swabs). Physicians and surgeons are notorious for collecting synovial fluids, surgical tissue, and many other specimens on swabs. In a CAP Today article from July 2009, Nancy E. Cornish, MD, and Carol A. Rauch, MD, PhD, recommended that the department of microbiology to do more to educate physicians, specifically surgeons, on how to collect "quality" microbiology specimens by giving the lab actual tissue and/or fluids in syringes instead of on swabs. If a swab, however, must be used, consider the flocked swabs. Liquid swabs may be the next best thing to a quality swab specimen.

The Gram stain is still the most important first result from the microbiology laboratory. It is imperative that Gram stains not only are performed properly but also performed on appropriate specimens and read in a timely fashion to provide preliminary results on which a physician can act. Gram stains conducted on an inappropriate specimen, such as stools and urines, also can give misleading results to a physician. (One resource for performing on appropriate specimens is the Clinical Microbiology Procedures Handbook from ASM Press.) In today’s microbiology laboratory environment where more and more procedures are being performed, the "bugs" are getting more resistant; and microbiologists are retiring at a steady pace, review protocols and determine if the lab is doing unnecessary or outdated procedures or procedures such as primary Gram stains on stools and urine specimens.

Are Gram-stain results available to the physician on Day 1? Clinicians use the Gram-stain results to validate their course of treatment. If the Gram-stain result is reported the same day as the preliminary report of the culture, then this is essentially a worthless result as well as a wasted effort. Monitoring Gram-stain turnaround times? A good benchmark for STAT Gram stains is one hour; four hours for routine Gram stains.

Rapid test technology

Little has changed in the microbiology laboratory in terms of how cultures are done. Specimens still need to be collected, transported to the laboratory, plated, incubated overnight, and evaluated the next day. This process still takes 18 to 24 hours. But today, physicians want results sooner. Literature suggests that rapid microbiology results impact lives and lower patient costs. According to Doern, et al, rapid results lead to fewer imaging procedures, fewer days on intubation, fewer days in intensive-care units, and decreased length of hospital stay.

This does not mean that the lab has to do PCR tests on everything. Before jumping into the world of molecular, a medical laboratory needs to answer several questions:

1. Is this test result going to improve service/patient care?
2. Will this test result change/improve therapeutic choices?
3. Is this a high-volume test that makes it budget neutral?

Additionally consider that there are a few instances where laboratory tests require molecular testing:

• where sensitivity of the test is critical (i.e., HSV-1);
• encephalitis where culture is dangerous (i.e., small pox, SARS), and
• where quantitative analysis is necessary (i.e., HIV viral load).

Molecular testing is not for every lab, and not every lab has the same needs.

Automating micro

Today’s microbiology lab needs to use automation as much as possible to perform tasks that are repetitive and/or frequently batched, that can be standardized, and/or that eliminate multiple steps in a process.

Automation of blood culture and identification, and ID/AST systems enables microbiology labs to work more efficiently and report ID/AST results much faster. Develop ID and susceptibility reporting practices on the basis of when results are available with the automated ID/AST system. For example, today’s technology allows for ID/AST results to be available within 8 to 10 hours. So implementing reporting strategies that allow results to go to the patient cart the same day will improve laboratory result turnaround time. According to Barenfanger, the average length of stay can be decreased by two days, average turnaround time by 5.2 hours, and mortality by 1.7%. The average total cost savings per result is $2,395. ⁵

Other types of automation available today contributing to increased efficiency are automated Gram stainers and plate streakers. This type of automation is thought by some to be best suited for large-volume laboratories. Weighing the challenges discussed here, consider the advantages of these systems, and study how automating these processes could improve overall microbiology efficiency. Evaluate Gram staining: Does the lab perform Gram stains 24/7? Do those Gram stains performed have to be reviewed on other shifts? Are many of the Gram stains performed on second and third shift over- and/or under-decolorized? Is this causing additional workload for the microbiology lab? Are corrected reports being generated? If this is the case, look at automating the Gram-staining procedure, which would standardize this process and procedure.

Consider similar scenarios for the automated plate streaker. How many cultures and patient results are delayed due to poor isolation technique? How many re-isolations are being done in the lab? How many ID/AST cannot be done the first day due to poor isolation? These issues can be resolved with an automated plate streaker. Automated plate streakers not only help reduce labor associated with streaking plates but also add benefits such as increased capacity, and improved turnaround times improved efficiency in processes, and shift the workload from non-technical tasks to brain-oriented tasks often associated with microbiology cultures.

Going "back to basics" to review processes in the laboratory can also be an opportunity to invite an outside organization’s review, which can be beneficial.

Anne R. Beall, corporate accounts project manager at bioMérieux Inc. in Durham, NC, has 22 years of experience in the clinical microbiology laboratory as well as substantial knowledge of automation and LEAN/Sigma.

References

1. Wage and Vacancy Report: Laboratory Workforce Shortage Reaches Crisis. Retrieved from http://www.ascp.org/MainMenu/students/Laboratorystudents/ASCP-Wage-and-Vacancy-Report.aspx. Accessed on October 28, 2009.
2. Bersch C. Retirement challenge looms. MLO. 2008;40(1):4.
3. Ernst DJ. Controlling blood culture contamination rates. MLO 2004;36(3):14-18.
4. Doern GV, Vautour R, Gaudet M, Levy B. Clinical Impact of Rapid In Vitro Susceptibility Testing and Bacterial Identification. J Clin Microbiol. 1994;32(7):757-1762.
5. Barenfanger J, Drake C, Kaich G. J Clin Microbiol. 1999;37(5):1415–1418.

Details create the big picture

By Debbi Tiffany, MSEd, MT(ASCP) SC, SLS

In clinical chemistry, the evolution of how data is utilized by caregivers continues to require laboratories to respond with increasing layers of detailed information. As more health insurers and government agencies seek measurement of the quality of patient care, the laboratory is poised to provide that data, often from information it already has.

eGFR as adjunct/replacement

Adoption of the calculated glomerular filtration rate (also known as electronic glomerular filtration rate, or eGFR) as an adjunct to or replacement for the 24-hour urine creatinine clearance test has not been without its problems. Using the serum creatinine, gender, age, and race, it is possible to calculate the glomerular filtration rate — the basis of the traditional creatinine clearance test — but without the usual problems associated with 24-hour urine collection. The impetus to performing this calculation stems from the National Kidney Disease Education Program, whose primary goal is to improve the early detection and treatment of kidney disease. Many labs continue to struggle with the mechanics of providing this calculation to their physicians. Issues encompass:

• which calculation to use (Modification of Diet in Renal Disease, or MDRD, or Cockcroft-Gault);
• whether or not the laboratory information system can support the calculation; and
• whether or not to calculate the eGFR on all creatinine tests performed by the laboratory or specifically by request.

While these studies are far from definitive at this point,
the popular press has taken kernels of information and
helped spur the demand for vitamin D testing.

Many instrument and reagent vendors have adopted the isotope-dilution mass-spectrometry (IDMS) standardization for their creatinine methods, although this method is still not universal. The difference in creatinine values between IDMS and non-IDMS methods, along with normal ranges, makes eGFR testing an ongoing situation that requires good communication between the laboratory and caregivers who utilize creatinine test results.

The EAG calculation debate

Estimated average glucose (EAG) is another calculation based on existing clinical-chemistry data that is receiving increased attention from healthcare providers as well as insurers. One of the challenges in diabetes care is helping the patient better understand the relationship between his daily glucose levels as measured by self-monitored blood-glucose testing versus a quarterly or semiannual hemoglobin A1c measurement performed by the laboratory. The EAG calculation can provide a clear interpretation of a patient’s glycemic status — essentially comparing "apples to apples." The results of the A1c derived average glucose (ADAG) study demonstrated a linear relationship between A1c levels and average glucose levels in both type 1 and type 2 diabetics. A previous calculation derived from the Diabetes Control and Complication Trial was based on a much more limited study than the ADAG, and values from this calculation are higher than the EAG values. While the American Diabetes Association and the American Association for Clinical Chemistry both have endorsed the use of the calculation, ongoing debate and additional studies of the EAG calculation continue.

Vitamin D

There is probably not a clinical-chemistry laboratory in the country that has not experienced a marked increase in the number of requests for vitamin D testing. Low vitamin D status has long been associated with osteopenia, osteoporosis, and fracture risk. Meta-analysis has provided some intriguing possibilities, associating low vitamin D levels to increased risk of certain cancers, type 1 diabetes, heart disease, multiple sclerosis, Alzheimer’s disease, and overall mortality. While these studies are far from definitive at this point, the popular press has taken kernels of information and helped spur the demand for vitamin D testing. But what can be termed a low vitamin D level? Unlike glucose or sodium, where population studies can define a true normal range, vitamin D levels have many variables that must be considered to determine a normal range. Because of the effect of sunlight on 7-dehydrocholesterol in the skin, vitamin D levels are affected by such variables as season, geographic location, population ethnicity, and gender. Establishment of a meaningful normal range would have to include these variables. Our immediate knowledge of vitamin D metabolism and what should be considered "healthy" levels is also based on dietary intake recommendations that are more than 50 years old.

Currently, the Institute of Medicine is conducting a study to determine updated dietary-intake levels for vitamin D. It is expected that the existing adult recommended daily intake of 200 IUs to 400 IUs will be adjusted based on more up-to-date scientific data. Finally, laboratories need to be aware of the lack of method standardization for vitamin D testing at this time. Different methods will yield different results, which can lead to confusion if a physician utilizes different laboratories for vitamin D testing and tries to compare the two values. The National Institute of Standards and Technology is now working on providing standardized reference material for quality control and calibration of vitamin D testing. As with eGFR and EAG, ongoing communication between the laboratory and physicians regarding the ins and outs of vitamin D testing will be essential in providing meaningful details to create the big picture of patient care.

Debbi Tiffany, MSEd, MT(ASCP) SC, SLS, is the director of Laboratory Services at SwedishAmerican Health System, Rockford, IL.

What’s new in

 

By Jeanne M. Isabel, MSEd, CLSpH(NCA)

Worked in the hemostasis department lately? No? You may be surprised to find some new testing protocols. Hemostasis is a discipline that is greatly affected by treatment therapies and new medications that appear in the marketplace; hemostasis is a study that makes keeping up with testing technologies difficult and the world of pharmaceuticals even more challenging.

Using the Fritsma Factor

Did you know that PCR testing of saliva for CYP2C19 associated with clopidogrel is being done by Quest Diagnostics? The test may be used to screen patients prior to clopidogrel therapy in an effort to establish the correct dosage or to switch to alternative anti-platelet therapy. It is the first saliva-based PCR available for clinical testing.

The updated laboratory testing guidelines are available online from the 2009 International Society on Thrombosis and Hemostasis regarding an update for lupus anticoagulant detection. This report appears in the October 2009 Journal of Thrombosis and Hemostasis. Some highlights include grading for appropriateness of testing, double centrifuging for platelet-poor plasma, and tests that are not recommended, to name a few. Both of these topics are covered on the Fritsma Factor website (see The Fritsma Factor below).

Check out CLSI

Another source for laboratory guidelines is the Clinical Laboratory Standards Institute (CLSI). A recent document "Standardization of platelet function testing by aggregometry" has been published for use by clinical laboratories worldwide. Historically, there has been little standardization surrounding platelet function testing. This guideline, available at www.clsi.org/source/orders/free/h58-A.pdf , provides sections addressing different methods of aggregometry testing. Readers can find information on a particular method or area of interest, such as specimen storage and transfer temperatures, sample selection for various methodologies, establishment of reference intervals, result reporting, result analysis, assay validations, and troubleshooting. Douglas J. Christie, PhD, F(AHA), chair of the subcommittee that developed the document, points out that "platelets, regardless of their absolute numbers, may be suboptimal in function and lead to a clinical bleed."¹ Platelet function may also be suppressed by use of medication in treatment.

Read more about the basics of platelet aggregometry in the 2007 article by George Fritsma in Clinical Laboratory Science,² the journal of the American Society for Clinical Laboratory Science, which outlines the specimen requirements and methodology for platelet-function testing by aggregometry and lumiaggregometry. A description of the various agonists used in aggregometry is listed, along with a summary of responses in various platelet disorders. This issue of the journal also has focus articles on thrombocytopenia and qualitative platelet disorders.

Platelet activation, oral anticoagulants, and more

Research on new cardiac markers and treatment strategy effects on platelet activation is described by Storm, et al. These researchers have identified "whole blood choline as a potential marker reflecting coronary plaque instability, platelet activation, and tissue ischemia." A standard treatment for patients with troponin-positive acute coronary syndrome is tirofiban which is a "short-acting non-peptide inhibitor of the GPIIb/IIIA receptor."³ Aspirin and clopidogrel represent current standard antiplatelet agents blocking platelet cyclooxygenase-1 and thromboxane A2. This new drug is associated with a lower incidence of ischemic events.

For information beyond the scope of anti-platelet therapy, updates related to oral anticoagulants, unfractionated heparin, and direct thrombin inhibitors is the focus in Clinical Laboratory Science 2004, issue two. There are a large number of adults on oral anticoagulant therapy, and regulation of the correct dosage to get the INR in the therapeutic range may take some trial and error.

A list of drugs that potentiate vitamin K antagonist and those that decrease anticoagulant response is included in the article by David McGlasson.⁴ A comparison of unfractionated heparin and low molecular weight heparin (LMWH) is discussed in the article by Adler.⁵ This article also includes a discussion of the preferred method of monitoring LMWH by chromogenic anti-Xa assay. Then look at the Fritsma Factor website to view the question/answer discussion on antithrombin in the anti-Xa assay.

Whether a seasoned hematologist or a generalist being asked to cover new departments, use these resources for current information. The quest for continuous education keeps getting more convenient.

Jeanne M. Isabel, MSEd, CLSpH(NCA), is an associate professor at the School of Allied Health Professions in the College of Health and Human Sciences at Northern Illinois University, DeKalb, IL.

References

1. McDaniel G. Standardization of platelet function testing by aggregometry through new CLSI guideline. Lab Medicine. 2009;40(5):269-270. doi10.1309/LMIZX13GDWBBH9NA
2. Fritsma G. Platelet function testing: Aggregometry and lumiaggregometry. Clin Lab Sci. 2007;20(1):32-37.
3. Storm C, Oliver D, Lueders C, Ulrich F, Moekel M. Effect of the glycoprotein IIb/IIIa inhibitor tirofiban on concentrations of whole blood choline in acute coronary syndromes. Lab Medicine. 2008;39(6):349-355.
4. McGlasson DL. (2004). Oral Anticoagulants. Clin Lab Sci.
5. Adler BA. Unfractionated heparin and other antithrombin medicated anticoagulants. Clin Lab Sci. 2004;17(2):113-117.

The Fritsma Factor is an online resource for keeping up to date and obtaining answers to questions on hemostasis at www.fritsmafactor.com. The Fritsma Factor, an interactive resource, was started by George A. Fritsma, MS, MT(ASCP), as a resource for laboratory practitioners to share information and knowledge. No matter if information is needed about hemostasis conferences, abbreviations, audio modules, or a forum for asking a question, the Fritsma Factor is the place to look. The website features a blog with commentary and news; an "Ask George" section where Fritsma answers questions submitted by readers; and educational presentations.

Fritsma is an associate professor in the Department of Pathology at the University of Alabama-Birmingham where he started the website http://uabcoag.net, another comprehensive source of information for both lay people and healthcare professionals. This website features a comprehensive list of thrombotic or hemorrhagic conditions along with a list of laboratory assays that may be used to assess risk, diagnose, or monitor the conditions; a glossary of hemostasis terms with abbreviations; and reference intervals for infants, children, and adults with thrombotic or hemorrhagic disorders.