SMART TESTING CARLO LUTZ, MD HYUNG J. CHO, MD Department of Emergency Medicine, Director, Quality and , Jacobi Medical Center, Bronx, NY Division of Hospital Medicine; Assistant Professor of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY

BRIEF ANSWERS TO SPECIFIC CLINICAL QUESTIONS Are we causing by ordering unnecessary blood tests?

68-year-old woman is admitted for needed for each test, and the possibility that A community-acquired pneumonia. She re- tests may need to be rerun. Yet about 3 mL of ceives antibiotics, and her condition begins to blood is suffi cient to perform most laboratory improve after 2 days. She has her blood drawn tests even if the test needs to be rerun.2 daily throughout her admission. On hospital day 3, she complains of fatigue, ■ CAN BLOOD DRAWS CAUSE ANEMIA? and on day 4, laboratory results show that her A relationship between the volume of blood and hematocrit values have fall- drawn and iatrogenic anemia was fi rst de- en. To make sure this result is not spurious, her scribed in 2005, when Thavendiranathan et blood is drawn again to repeat the test. On day al3 found that in adult patients on general 5, her hemoglobin level has dropped to 7.0 g/ medicine fl oors, the volume of blood drawn dL, which is 2 g/dL lower than at admission, strongly predicted decreased hemoglobin and and she receives a transfusion. hematocrit levels. For every 100 mL of blood On day 7, her hemoglobin level is stable drawn, hemoglobin levels fell by an average at 8.5 g/dL, and her physicians decide to dis- of 0.7 g/dL, and 13.9% of the patients in the Iatrogenic charge her. The morning of her discharge, as study had iron studies and fecal occult blood anemia from a nurse is about to draw her blood, the pa- tests performed to investigate anemia. tient asks, “Are all these blood tests really Kurniali et al4 reported that during an av- blood draws necessary?” erage admission, 65% of patients experienced is common, a drop in hemoglobin of 1.0 g/dL or more, and ■ DO WE DRAW TOO MUCH BLOOD? 49% developed anemia. serious, and 5 This case portrays a common occurrence. Salisbury et al, in 2011, studied 17,676 pa- unnecessary Signifi cant amounts of blood are drawn from tients with acute myocardial infarction across patients, especially in critical care. Clinical 57 centers and found a correlation between uncertainty drives most laboratory testing or- the volume of blood taken and the develop- dered by physicians. Too often, however, these ment of anemia. On average, for every 50 mL of blood drawn, the risk of moderate to severe tests lead to more testing and interventions, iatrogenic anemia increased by 18%. They without a clear benefi t to the patient.1 also found signifi cant variation in blood loss When blood testing leads to more testing, from testing in patients who developed mod- a patient’s hemoglobin and hematocrit can erate or severe anemia. The authors believed fall. Symptomatic iatrogenic anemia is asso- this indicated that moderate to severe anemia ciated with signifi cant morbidity for patients was more frequent at centers with higher than with preexisting cardiopulmonary disease. average diagnostic blood loss.5 We draw much larger volumes of blood This relationship has also been described in than most testing guidelines say are necessary. 2 patients in intensive care, where it contributes One author has noted that 50 to 60 mL of to anemia of chronic disease. While anemia blood is removed for each set of tests, owing to of critical illness is multifactorial, phlebotomy the size of collection tubes, multiple reagents contributes to anemia in both short- and long- doi:10.3949/ccjm.83a.15108 term stays in the .6

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■ CHOOSING WISELY GUIDELINES week. They found that simply making provid- The Choosing Wisely initiative of the Ameri- ers aware of the cost of their tests reduced the can Board of Internal Medicine Foundation number of tests ordered and resulted in signifi - collects recommendations by a number of cant hospital savings. medical specialty societies to reduce overuse Another strategy is to use pediatric col- of healthcare resources.7 The Critical Care lection tubes in adult patients. A 2008 study Societies Collaborative recommends ordering in which all blood samples were drawn using diagnostic tests only when they answer specifi c pediatric tubes reduced the blood volume re- clinical questions rather than routinely. The moved per patient by almost 75% in inpatient Society of Hospital Medicine also recommends and critical care patients, without the need against repeat complete blood cell count and for repeat blood draws.9 However, Kurniali et blood chemistry testing because it may contrib- al found that the use of pediatric collection ute to anemia, which is of particular concern in tubes did not signifi cantly change hemoglo- patients with cardiorespiratory disease. bin fl uctuations throughout patient hospital stays.4 ■ POSSIBLE HARM Corson et al10 in 2015 described an inter- The Critical Care Societies Collaborative, in vention involving detailing, auditing, and its Choosing Wisely Guidelines, specifi cally giving feedback regarding the frequency of cites anemia as a potential harm of unnecessary laboratory tests commonly ordered by a group phlebotomy, noting it may result in transfusion, of hospitalists. The intervention resulted in a with its associated risks and costs. In addition, modest reduction in the number of common aggressive investigation of incidental and non- laboratory tests ordered per patient day and pathologic results of routine studies is wasteful in hospital costs, without any changes in the and exposes the patient to additional risks. length of hospital stay, mortality rate, or read- mission rate.10 ■ REDUCING PHLEBOTOMY DECREASES IATROGENIC ANEMIA ■ THE CLINICAL BOTTOM LINE Order tests Since the relationship between excessive As a general principle, diagnostic testing should only to answer phlebotomy and iatrogenic anemia was de- be done to answer specifi c diagnostic questions specifi c clinical scribed, hospitals have attempted to address and to guide management. Ordering of diag- the problem. nostic tests should be decided on a day-to-day questions— In 2011, Stuebing and Miner8 described an basis rather than scheduled automatically or not routinely intervention in which the house staff and at- done refl exively. In the case of blood draws, tending physicians on non-intensive care sur- the volume of blood drawn is signifi cantly in- gical services were given weekly reports of the creased by unnecessary testing, resulting in cost of the laboratory services for the previous higher rates of hospital-acquired anemia. ■ ■ REFERENCES from intensive care: the impact of restrictive prac- 1. Ezzie ME, Aberegg SK, O’Brien JM Jr. Laboratory testing in the inten- tice. Intensive Care Med 2006; 32:100–109. sive care unit. Crit Care Clin 2007; 23:435–465. 7. American Board of Internal Medicine Foundation. Choosing Wisely. www.abimfoundation.org/Initiatives/Choosing-Wisely.aspx. Accessed 2. Stefanini M. Iatrogenic anemia (can it be prevented?). J Thromb Hae- April 19, 2016. most 2014; 12:1591. 8. Stuebing EA, Miner TJ. Surgical vampires and rising health care expenditure: 3. Thavendiranathan P, Bagai A, Ebidia A, Detsky AS, Choudhry NK. Do reducing the cost of daily phlebotomy. Arch Surg 2011; 146:524–527. blood tests cause anemia in hospitalized patients? The effect of diag- 9. Sanchez-Giron F, Alvarez-Mora F. Reduction of blood loss from nostic phlebotomy on hemoglobin and hematocrit levels. J Gen Intern laboratory testing in hospitalized adult patients using small-volume Med 2005; 20:520–524. (pediatric) tubes. Arch Pathol Lab Med 2008; 132:1916–1919. 4. Kurniali PC, Curry S, Brennan KW, et al. A retrospective study inves- 10. Corson AH, Fan VS, White T, et al. A multifaceted hospitalist quality tigating the incidence and predisposing factors of hospital-acquired improvement intervention: decreased frequency of common labs. J anemia. Anemia 2014; 2014:634582. Hosp Med 2015; 10:390–395. 5. Salisbury AC, Reid KJ, Alexander KP, et al. Diagnostic blood loss from phlebotomy and hospital-acquired anemia during acute myocardial ADDRESS: Carlo Lutz, MD, Jacobi Medical Center, Department of Emergency infarction. Arch Intern Med 2011; 171:1646–1653. Medicine, 1400 Pelham Parkway South, Bronx, NY 10461; 6. Walsh TS, Lee RJ, Maciver CR, et al. Anemia during and at discharge [email protected]@gmail.com

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