Hematologic Exams Flashcards
The blood is __% of body weight
6-8
What is found in the buffy coat?
WBC and platelets
Plasma is considered as liquid part of blood partly because it contains
> 90% water and a dilute solution of salts, glucose, amino acids, vitamins, urea, proteins and fats
What are the other components of plasma?
dissolved solids (i.e., albumin and antibodies, lipids, carbohydrates, hormones, amino acids, and electrolytes) It also has blood coagulation proteins
How numerous are red blood cells exactly?
1 µL of blood = 5 million RBCs
Why is arterial blood bright red and venous blood dark red?
Arterial blood- oxyhemoglobin
Venous blood- deoxyhemoglobin
How least numerous are wbcs?
1 µL of blood = ~5,000-10,000 WBCs or 5.0x109 per L of blood
What are the unique functions of wbcs?
Neutrophils- bacterial infxn
Eosinophils – allergic reactions and parasitic infection
Basophils – histamine, inflammatory response
Lymphocytes – viral infections
Monocytes – antigen presenting, phagocytic
How many platelets are there in 1 microliter of blood?
300,000
Platelets are important in several stages of ________
Hemostasis (blood clotting)
What are the common diseases diagnosed by hematologic tests?
anemia, leukemia, and inherited blood disorders (e.g., hemophilia, sickle cell anemia, etc.)
T or F: hemostasis studies such as coagulation tests and fibrinolysis are classified as qualitative tests
False (?) nakalagay siya sa others
Routine hematology tests may be performed using:
Automatic Hematology analyzers
Manual techniques: counting
What are the usual specimens used for testing?
Capillary blood (good for blood smears, cannot be repeated unless collected again) Venous blood (when large sample is reqd; usually collected in tubes)
Why is the hemoglobin test one of the most common tests performed?
- precise
- simple to perform
- easily standardized
The hemoglobin test is also an indirect evaluation of ______
Oxygen carrying capacity of blood
*Important in detecting blood loss and anemia as well as in monitoring treatment of certain RBC disorders
T or F: hemoglobin tests use capillary blood onlu
False, both c and v part of cbc
Methods involved in hemoglobin tests
Specific gravity
Cyanmethemoglobin (most recommended)
Azide methemoglobin
Acid hematin (for office practice and laboratory class; Blood is usually mixed with diluted hydrochloric acid then compared with a standard and color comparators to measure hemoglobin)
The acid hematin method uses the sahli dilution tube which involves
Main parts: graduated glass tube, color comparators, glass stirrer, and Sahli’s pipette to measure 20 µl of blood
- Tubes commonly used are square with graduations in percent on one side and grams/100 ml on the other
- Color comparators are made of brown colored glass and some better instruments have glass prisms
What are the hemoglobin reference ranges for NEWBORNS?
Newborn 16-23 g/dL X10 160-230 g/L (SI units)
What are the hemoglobin reference ranges for ADULT MALES?
Adult Males 13-17 g/dL X10 130-170 g/L
What are the hemoglobin reference ranges for CHILDREN?
Children 10-14 g/dL X10 100-140 g/L
What are the hemoglobin reference ranges for ADULT FEMALES?
Adult Females 12-16 g/dL X10 120-160 g/L
Given a hemoglobin value of 23 g/L, what is the estimated hematocrit?
89 g/L
What does a high hemoglobin test indicate?
Increased red cell production to compensate chronically low oxygen levels in the blood due to lung disease or living at high altitudes ® May be due to dehydration, smoking, and bone marrow disorders
If a patient has low hemoglobin, what are the possible reasons why this is so?
anemia due to pregnancy, blood loss, liver damage, iron deficiency, etc.
What are the general physical factors affecting hemoglobin levels?
Diet (iron deficiency affects rbc production)
Lifestyle (active = higher hemoglobin)
Altitude of residence (reduced oxygen pressure/thin air = increased rbc prod= higher hgb)
Hematocrit is defined as
Amount of space taken up by rbcs in the blood
In what situations is hematocrit determination useful?
Useful in the diagnosis of anemia and polycythemia,
screening potential blood donors,
evaluation of anemia therapies and in
estimating blood loss after hemorrhage or trauma
Methods involved in hematocrit determination
- Manual Wintrobe Macromethod (volume of rbc is read directly on tube)
- Manual Micromethod
- Automated Method
What are the normal hematocrit values seen in wintrobe method?
Women: 37-47%
Men: 42-52%
What would a depressed hematocrit indicate? Elevated hematocrit?
Low: Anemia or bleeding; increased: polycythemia, pregnancy, dehydration, living in high altitudes, low availability of oxygen
(See hematocrit ref ranges in trans!!)
Hematocrit determination which is speedy, accurate, reproducible, uses microcapillary tube
Microhematocrit method
Disadvantages of microhematocrit method
• Buffy coat-red cell interface is not always clear-cut
® Minor reading error may occur
® Less reliable and less accurate for determining blood indices
What is the characteristic appearance of normal blood samples centrifuges in microhematocrit tube?
Transparent pale yellow plasma and narrow whitish tan layer above red cell layer for buffy coat
A very pale yellow plasma in microhematocrit would indicate?
Elevated bilirubin levels
An opaque plasma in microhematocrit method would mean?
High triglyceride levels
A prominent buffy coat in microhematocrit method would indicate?
Elevated WBC
A complete blood count is also known as __________
Full blood count or hematology profile blood test
*performed using hematology analyzers or hematology cell counters
What are the advantages of examining blood components in cbc?
Provides vital information on the type, number, and appearance of cells in the blood, especially RBCs, WBCs, and platelets
What are the tests included in cbc?
® RBC count ® WBC count ® Hemoglobin ® Hematocrit ® RBC indices ® WBC differential count ® Platelet count or platelet estimate ® Evaluation of blood cell morphology
Fill in the blanks of method of cbc:
The blood is drawn using a _____________ and mixed with the appropriate diluent before it is transferred to the ___________
The blood is drawn using a specialized pipette and mixed with the appropriate diluent (for ease of counting) before it is transferred to the hemocytometer
(See differences in pipettes)
Degree of dilution and type of diluting fluid used for RBC
Usually diluted 1:200
Diluting fluid must be isotonic to protect the delicate RBCs from hemolysis
Degree of dilution and type of diluting fluid used for WBC
ammonium oxalate (to lyse RBCs; usually contains dye to make the nuclei prominent and for ease in counting), Diluted 1:100 using LeukoChek system or 1:20 for LeukoTIC system
Degree of dilution and type of diluting fluid used for platelets
Ammonium oxalate, 1:100
The hemocytometer contains the blood counting chamber which is used to count
Number of cells in csf or other body fluids
Bacteria
(See hemocytometer reading oi!)
How many squares does the hemocytometer have?
nine equally-sized large squares
Size of each square and ruled area
® Each square is 1mm wide x 1 mm long ® Entire ruled area is 9 mm2 or 3 mm wide x 3 mm long
In the hemocytometer, the RBCs are counted where? How bout WBCs?
® The RBCs: large center square comprised of 25 smaller squares
® The WBCs:4 large corner squares comprised of 16 smaller squares
Manner of counting in hemocytometer
The cells are counted from left to right and then from top to bottom in an “inverted L” pattern in each square (avoids double counting)
It is a commonly used method and is a usual component of CBC and aids physician in diagnosis and treatment of many diseases
RBC Count (see procedure and formulae for counting rbcs)
Normal values for erythrocyte count of females
Female 4.0 – 5.5 x 10^6 RBCs/mm3 or 4.0 – 5.5 x 10^12 RBCs/L
Normal erythrocyte count for males
Male 4.5 – 6.0 x 10^6 RBCs/mm3 or 4.5 – 6.0 x 10^12 RBCs/L or
Increased rbc counts may be due to
Erythrocytosis due to polycythemia vera or living at high altitude
Probable causes of decreased rbc count
< Iron Deficiency Anemia < Folic Acid Deficiency < Sickle Cell Anemia < Acute or chronic blood loss < B12 Deficiency
round, slightly iridescent structures with definite outline and well-defined nuclear structures
Leukocytes (see procedure, formulae and reference ranges for wbc count)
Probable causes of leukocytosis or increase in wbc count
§ Pathogenic: infection, leukemia, polycythemia
§ Physiological: exercises, exposure to sunlight, obstetric labor stress, anesthesia
Probable causes of leukopenia/leukocytopenia or decrease in wbc count
§ Viral infections (e.g., HIV), ionizing radiation, certain chemicals, chemotherapy drugs
• Characteristics of individual red cells and aids in the diagnosis of anemia (determining type of anemia and in therapy depending on calculated values)
Red cell indices
((RED BLOOD CELL INDICES))
Volume of the average red cell in a given sample of blood expressed in femtoliters (fl) or cubic microns (μm3)
Mean corpuscular volume (see trans for formula)
Normal value : MCV 80-100 fl or μm3
• Note that MCV is approximately 3 times that of MCH
((RED BLOOD CELL INDICES))
Amount of hemoglobin by weight in the average cell of a blood sample. It is directly proportional to the amount of hemoglobin and red cell size and expressed in picograms (pg) or micrograms (μg)
Mean corpuscular hemoglobin (see trans for formula)
Normal value: MCH 27-32 pg or μg
Concentration of hemoglobin in the RBCs relative to their size. It may indicate whether the cells are normochromic or hypochromic. It is expressed in g/L or %g/dL
Mean corpuscular hemoglobin concentration
Normal value: MCHC 33.0-38.0% or g/dL
