Hematology 5th Edition By Elaine Keohane

An Overview of Clinical Laboratory Hematology MULTIPLE CHOICE 1. Hematology is the study of 2. blood cells. 3. serum electrolytes. 4. plasma hormone levels. 5. bacteria in the blood. ANS: A Hematology is the study of blood cells—their number, production, and morphology. Plasma and serum electrolytes and hormone levels are evaluated in various subdivisions of clinical chemistry, and bacteria are evaluated in clinical microbiology. DIF: Cognitive Level: 1 REF: Page 1 1. The morphology of blood cells is important to evaluate 2. every time a complete blood count (CBC) is requested on a patient. 3. when an instrument-generated flag is obtained. 1. when flag limits established by medical laboratory scientists in the laboratory are exceeded. 2. when the white count is elevated. ANS: C Every laboratory must determine—based on its instrumentation, needs of the clinician and other parameter flags that alert the medical laboratory scientist to the necessity for further evaluation— when it is necessary to evaluate cell morphology. Many instrument-generated flags, although useful, may not require review. If an automated CBC does not suggest the need, no reason exists to evaluate the blood film, even if the white count is elevated. DIF: Cognitive Level: 2 REF: pages 4-5 1. Who is ultimately responsible for determining the specimen integrity before analysis? 2. medical laboratory professional 3. nursing staff 4. phlebotomist 5. specimen-processing personnel ANS: A The medical laboratory scientist is responsible for ensuring the integrity of a specimen before analysis. Only he or she can judge whether the specimen is acceptable so that valid results can be obtained. Acceptable criteria include such things as type of specimen for the test ordered (e.g., blood, serum, urine); appropriate additive present (if needed) and amount of specimen relative to the additive; time interval since obtained; and presence or absence of hemolysis, lipemia, and other similar conditions. None of the other personnel named have the education and understanding to fully make that judgment. DIF: Cognitive Level: 2 REF: Page 5 1. Hematocrit is also called 2. white cell count. 3. bone marrow examination. 4. red blood cell (RBC) count. 5. packed red cell volume. ANS: D Historically the hematocrit was determined by centrifuging an aliquot of anticoagulated whole blood under specified conditions (e.g., centrifugal force, capillary tube length, and bore diameter) and then determining the ratio of the space occupied by the packed red cells compared with that of the entire blood volume in the capillary tube, often expressed as a percentage. Hence, it is also called the packed red cell volume.