TOPICS. Continuing Education April 2015 Volume 17 Number 2. Journal of. Inside This Issue. Official publication of the American Medical Technologists

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1 Journal of TOPICS & ISSUES Official publication of the American Medical Technologists Continuing April 2015 Volume 17 Number 2 Inside This Issue Identifying Chronic Kidney Disease: An Overview of the Equations for Estimating Impaired Renal Function Hematology Case Study: A normocytic, normochromic anemia Lot-to-lot Variation: How to Detect it, Measure it and Evaluate it

2 Journal of Continuing April 2015 Volume 17 Number 2 Contents TOPICS &ISSUES 36 Article 419 Identifying Chronic Kidney Disease: An Overview of the Equations for Estimating Impaired Renal Function Connie Bell and Michael Spigler, American Kidney Fund 39 Questions for Article Article 420 Hematology Case Study: A normocytic, normochromic anemia Georgia A. McCauley 43 Questions for Article Article 421 Lot-to-lot Variation: How to Detect it, Measure it and Evaluate it David Plaut and Nathlie Lepage CENTER PULLOUT SECTION Chicago Convention Preliminary Program 46 Questions for Article Consultant s Corner Medical Mission Trip To India Kathleen Voldish 50 Abstracts From the Current Literature 52 AMT Directory Editor Gerard P. Boe, PhD Associate Editor Diane Powell Business Office American Medical Technologists W. Higgins Rd., Suite 150 Rosemont, IL address: mail@americanmedtech.org Web Site: Journal of Continuing Topics & Issues (ISSN ) is published in January, April, and August under the sponsorship of the American Medical Technologists, W. Higgins Rd., Suite 150, Rosemont, Illinois Copyright 2015 by American Medical Technologists. Subscriptions include three issues of Journal of CE Topics & Issues and three issues of AMT Events: $50.00/year + $10 postage for foreign countries. Members may not deduct subscription price from dues. Postmaster: Please send change of address to AMT, W. Higgins Rd., Suite 150, Rosemont, Illinois Moving? Be sure AMT publications move with you. Send your new address and old mailing label from an AMT publication to AMT six weeks before you move. Cover photo: Firestorm microscape, Eric Clark, National High Magnetic Field Laboratory, Florida State University, Tallahassee. Journal of Continuing Topics & Issues April

3 Article Clock Hours Identifying Chronic Kidney Disease: An Overview of the Equations for Estimating Impaired Renal Function by Connie Bell and Michael Spigler, American Kidney Fund Mike Spigler, MCHES, is Senior Director of Health Initiatives and for the American Kidney fund. He is a Master Certified Health Specialist. Connie Bell, RN, MPH, is Manager for the American Kidney Fund, She is a registered nurse and holds a Master s of Public Health. Background Chronic kidney disease (CKD) is currently the ninth leading cause of death in the United States. 1 CKD is the gradual loss of kidney function over time. It is a significant public health problem that results in poor patient outcomes and substantial healthcare costs for consumers and providers. Once a patient is diagnosed with CKD, the existing kidney damage oftentimes cannot be reversed; however, it may be possible to stop or slow further progression of CKD with medical interventions and dietary changes. Because it is possible to manage CKD, and health outcomes are often better when it is caught early, it is essential to prioritize early identification, especially in patients at highest risk. Those patients who are at higher risk for CKD include those with diabetes and hypertension. In 2012, diabetes caused 44 percent of new cases of kidney disease, and hypertension caused 28 percent of new cases. 2 Symptoms of CKD CKD is a slowly progressing, silent disease. It gradually worsens over months or years. Symptoms may not appear until the kidneys almost completely stop working. Some of the warning signs of CKD include: swelling or puffiness, particularly around the eyes or in the face, wrists, abdomen, thighs, or ankles; urine that is foamy, bloody, or coffee-colored; a decrease in the amount of urine; problems urinating or a change in the frequency of urination, especially at night; mid-back pain (flank), below the ribs, near where the kidneys are located; high blood pressure; urinating more or less often; feeling itchy; tiredness, loss of concentration; loss of appetite, 36 Journal of Continuing Topics & Issues April 2015 nausea and/or vomiting; numbness in hands and feet; darkened skin; and muscle cramps. 3 Tests for CKD It is important to note that these symptoms may not always be present. The only way to identify CKD is to monitor kidney function. There are many different tests for CKD. These include a urinalysis to look for abnormal amounts of protein or blood in the urine; a blood test to check serum creatinine levels and blood urea nitrogen (BUN); and, using the serum creatinine results, a calculation of the patient s estimated glomerular filtration rate (egfr). The estimated glomerular filtration rate (egfr) is the best overall indicator of kidney function. 4 egfr is used to screen for and detect kidney damage by seeing how well the kidneys are filtering the blood. egfr is calculated using equations that take into account serum creatinine, age, sex, and race (see below). 5 As such, it is a better test of kidney damage than the serum creatinine test alone. Other tests, such as for protein or blood in the urine, may be even better markers of early kidney disease and should be evaluated along with egfr. egfr The National Kidney Disease Program (NKDEP) strongly encourages clinical laboratories to routinely estimate glomerular filtration rate and report the value when serum creatinine is measured for patients 18 and older. An egfr that is calculated from serum creatinine is a simple and effective way that laboratories can assist health care providers in recognizing CKD among those with risk factors diabetes,

4 Article Clock Hour Hematology Case Study: A normocytic, normochromic anemia Georgia A. McCauley A 6-year-old African American male was seen in the emergency department with a fever of F., general malaise and severe leg pain. The following results were seen on the automated complete blood count (CBC) and differential. The CBC report was also flagged by the instrument for a peripheral blood smear review. The image below is from a Giemsa-Wright stained smear (x500). CASE STUDY GUIDED QUESTIONS & DISCUSSION 1. What is the implication of the complete blood count parameters and peripheral blood smear (PBS) image? The patient is 6-years-old and noting the age-specific pediatric reference ranges is significant when evaluating the laboratory results. The white blood cell (WBC) count initially appears elevated but according to the pediatric range, the WBC in only slightly elevated. Applying the rule of three (HGB x 3 = HCT ± 3) to the hemoglobin and hematocrit values indicate that the two parameters correlate. The rule of three is a fast mathematical accuracy check that could indicate instrument error or abnormal red blood cells. The rule of three only applies to normocytic, normochromic erythrocytes. 5,6 The hemoglobin (HGB), hematocrit (HCT), and red blood cell (RBC) count are all below the reference range indicating anemia. The HGB is critically low at 6.1 g/dl, therefore the anemia is severe. 3,6 Georgia A. McCauley, PhD, MBA, MT(AMT), Program Director, Associate Professor, Winston-Salem State University, Winston-Salem, NC (Image courtesy of Jennifer Jones, Winston-Salem State University) 40 Journal of Continuing Topics & Issues April 2015

5 Article Clock Hours Lot-to-lot Variation: How to Detect it, Measure it and Evaluate it. by David Plaut and Nathlie Lepage David Plaut, Plano, TX, is a consultant, AMT s book reviewer, and frequent speaker at AMT national and regional meetings. Nathlie Page is Clinical Chemist at Children s Hospital in Eastern Ontario, Ottawa, Canada. Shifts in patient results due to reagent lot changes (lot-to-lot variation, L2L) are a major issue for laboratories, and their investigation is both time-consuming and expensive. Algeciras-Schimnich et al. (1) point out the effect that reagent lot-to-lot changes can have on patient results and how these shifts, if large enough, could lead to misdiagnosis and inappropriate treatment. Here we propose a way to detect those analytes that in the past, have been seen to vary from lot to lot and propose a way to measure changes due to L2L variation. To find those analytes that are prone to variation, look at a current quality assurance survey (QAP) and the SD or % CV. Here are two examples: Marble Level I Granite Level I Current Cumulative Current Cumulative Mean SD % CV n The current and cumulative data for the Marble LI SDs are quite similar (1.4 and 1.6) whereas the SDs for Granite are quite different (2.3 and 4.9). The difference between the current level (assuming that only one of reagent was used to obtain the 30 points) and the cumulative data covering some 7 months suggests that changing 44 Journal of Continuing Topics & Issues April 2015 reagents (or calibrators) for Granite can result in significant changes in the results of both controls and patients. (You see that the means are only minimally different between the current and cumulative periods.) The ratios of cumulative SDs for Marble is 1.1 and Granite it is 2.0 (rounded). There is a statistical test the F-ratio that compares SDs and will indicate whether the two SDs are statistically (not necessarily clinically) significant. As a rule of thumb if the ratio of cumulative to current SDs is greater than 2, you should measure each new lot of reagent for a new mean. You may have asked how the means for current and cumulative data can be so close if the SDs vary. Consider the last four reagent lot means for Marble: 77, 79, 78, 77. This gives an overall mean of 77.8 (rounded) with a range of means of only two units (79-77). The last 4 four reagent lots for Granite yielded these means: 82, 74, 76, and 81. The mean (again rounded) is 78 and the range is eight units (82-74). This is the reason we do NOT use the mean to assess L2L changes. The % CV s also show a difference between the current and cumulative data for Granite, but not in Marble. Having found that Granite is not as stable/consistent as Marble, you may want to order as much of a lot as you can store so as to avoid doing the experiment to quantify the new mean with a change in lots. Keep in mind that a change in the means of your controls, probably indicates that the patient values will also change. The clinicians and their patients will not like this. continued on p. 45, after center insert