RBCs
Q. What symptoms could a patient have if they have a low HGB?
A. Fatigue, shortness of breath, weakness, pale skin, irregular heartbeat, lightheadedness, cold hands and feet, etc.
Q. What could an elevated WBC count indicate?
A. Infection, inflammation in your body, cancer, bone marrow disorders, etc.
Q. How does Wintrobe categorize anemias?
A. By the size of the erythrocytes
(Macrocytic, normocytic, or microcytic)
Q. How many fields do you observe for a WBC or PLT estimate?
A. 10 fields
Q. What is the Rule of Three?
A. A quick check of the hemoglobin and hematocrit results for normocytic, normochromic red cells.
HGB x 3 = HCT
RBC x 3 = HGB
RBC x 9 = HCT
Q. What are sources of error in hemoglobin measurement?
A. Hemolysis, icterus, and lipemia
Q. What type of WBC is higher in infants than adults?
A. Lymphocyte
Q. What is the typical size of RBCs seen in megaloblastic anemia?
A. MCV>100fL
Q. Under what magnification do you perform a WBC estimate?
A. 40x
Q. What is the formula to for a WBC estimate?
A. (total # of wbcs counted)/(number of fields counted) x 2000
Q. Using what magnification do you observe RBC morphology?
A. 100x oil
Q. Using what magnification do you perform a manual differential?
A. 100x oil
Q. What are causes of microcytic, hypochromic anemias?
A. Defective hemoglobin synthesis, Iron is unavailable for the synthesis of hemoglobin
Q. Using what magnification do you look for platelet clumping?
A. 10x
Q. What is the formula for a platelet estimate?
A. Total platelets/10 fields x 20,000 for wedge prep smears (x 15,000 for automated monolayer smears)
Q. What is the reference range for hemoglobin in conventional units?
A. 12.0-18.0 g/dL
Q. What is the reference range for WBCs in conventional units?
A. 3.6-10.6 x 103/μL
Q. What are quantitative results that define anemias?
A. 1. A decreased hemoglobin concentration
2. A reduced packed cell volume (Hematocrit) level
3. A decreased erythrocyte concentration
4. A decreased or increased RBC index—like MCV, MCH,or MCHC
Q. Under what magnification do you evaluate blood smear quality, color, and distribution of cells.
A. 10x
Q. What is the calculation for correcting a WBC count due to the presence of nRBCs?
A. (WBC count X 100) / (nRBCs + 100)
Q. A patient has a MCV of 67, what morphology would you see?
A. Microcytosis
Q. By what process do white blood cells leave circulation and enter tissues?
A. Diapedesis
Q. What is functional anemia?
A. A decrease in the ability of RBCs to carry oxygen to the tissues resulting in hypoxia
Q. How many fields do you observe for a WBC count differential?
A. As many as you need to reach the 100-cell differential
Q. What is the formula for calculating absolute values?
A. (% of cell type in diff)/100 x WBC count