HEMATOLOGY Flashcards
Reticulocyte Count
Increases during rapid blood loss or hemolytic diseases where RBCs are destroyed prematurely
Low Reticulocyte count Indicate 3 conditions
- Decreased production of RBCs by the bone marrow which can be caused by aplastic anemia, etc.
- Exposure to radiation • Chronic infection •
- Certain meds that damage bone marrow
• MCV –
Mean Corpuscular Volume
• MCH –
Mean Corpuscular Hemoglobin
• MCHC -
Mean Corpuscular Hemoglobin Concentration
• RDW –
Red Cell Distribution Width
Mean Corpuscular Volume MCV
average volume of red cells in a specimen.
Differentiates microcytic or macrocytic anemia • Low MVC = • Normal MVC = • High MVC =
microcytic anemia normocytic macrocytic anemia
Microcytic causes (TIA)
Thalassemmia Iron deficiency Anemia of chronic renal disease
Macrocytic causes are BAC-DRAMHypo)
B12 folate deficiency
Alcohol use
Chronic liver disease
Drugs
Reticulocytosis
Aplastic anemia
Myelodysplastic
Hypothyroidism
Mean Corpuscular Hemoglobin (MCH)
• Measure of the average MASS of hemoglobin contained by a rbc
Low MCH =
microcytic anemias;
High MCH =s
macrocytic anemia
Normal MCH
• Normal: 27 - 31 picograms/cell
Mean Corpuscular Hemoglobin Concentration (MCHC)
• Measure of the concentration of hemoglobin in a given volume of RBCs
Normal MCHC
• 32-36 g/dL
Low MCHC
(hypochromic) in microcytic anemias
Normal MCHC
(normochromic) in macrocytic anemias (due to larger cell size)
High MCHC (hyperchromic) in
spherocytosis, sickle cell and Hb C ds. w/ splenomegaly
Red Cell Distribution Width RDW
• Shows the difference in size between the smallest and largest red blood cells in a sample.
RDW normal
Normal range is ~ 12-15% variation in size
RDW average red cells are
6–8 micrometers
Questions during exam: meds that affect blood are Dont forget: ______ May need to question ________
• Medications list • Meds that affect the blood (ex. ASA, NSAIDS, Warfarin, Pentoxifylline, erythropoietin, neupogen, etc.) • Don’t forget HERBAL/VITAMINS/ SUPPLEMENTS • May need to question FAMILY HISTORY
Symptoms of Anemia Depend on HCDR
• Hgb level • Decrease in O2 carrying capacity of blood • Change in total blood volume • Rate at which these change
The concentration of DISSOLVED oxygen in the blood (CdO2) is _____________. This is known as the ________
directly proportional to the partial pressure of oxygen (PO2) in the gas. This is known as Henry’s Law.
The solubility coefficient of oxygen in blood (aO2) =
0.0031 mL / mmHg of oxygen / dL of blood.
CdO2 = Constant is
aO2 x PO2 (aO2 = 0.0031 mL O2/ mmHg O2 / dL blood) aO2 0.0031
• What would the concentration of dissolved oxygen be in the blood when the partial pressure of oxygen in the alveolar gas is 100 mmHg?
15 mL O2
Causes of Prolongation PTc
• Normal: INR 0.8-1.2 • Normal: PT 12-14 se
PT/INR evaluates how well together.
all of the coagulation factors in the extrinsic and common pathways of the coagulation cascade work
Included in PT/INR are:
factors I (Fibrinogen), II (Prothrombin), V, VII and X
Decrease in factor production or increase in factor destruction = prlonged PT
• Warfarin therapy • Vitamin K deficiency • Liver disease • DIC
Causes of Prolongation of PTT Normal PTT –
25-35 secs
What does PTT measure?
the integrity of the intrinsic system (Factors VIII, IX, XI, XII) and common clotting pathway
Abnormalities leading to prolonged PTT (VHHLD)
• Heparin - binds to antithrombin • Very severe vitamin K deficiency • Hemophilia A, B, and C • Liver disease • DIC
Fibrinogen Level Synthesized by
the liver
Fibrinogen Acute-phase reactant (APR =
proteins whose plasma concentrations increase in response to inflammation)
Extrinsic
3, 7
Fibrinogen Normal levels are
160-350 mg/dL
Fibrinogen levels less than
Levels < 100 mg/dL may be inadequate to form clot
Activated Clotting Time (ACT) Evaluate the
Evaluates the intrinsic and common pathways of coagulation
Normal clotting time is
90-120 seconds
Thromboelastography
Test that rotates blood sample to initiate clot formation Management of transfusion therapy in OR
Thromboelastography Measures clot formation: R value
Reaction time in min before the first evidence of clot is detected (efficacy of coagulation factors & fibrin formation)
Thromboelastography K value –
time from end of R until clot reaches 20mm tracing (speed of clot formation)
Thromboelastography Alpha angle –
size of angle formed by tangent line from beginning of K until 20mm point (information similar to K - reflects speed of fibrin accumulation & crosslinking)
Thromboelastography MA - Maximum amplitude –
greatest amplitude of tracing (reflection of maximum clot strength) 80% platelet function + 20% fibrin Assesses platelet count/function +fibrinogen activity
Thromboelastograph LY30 - Clot lysis index –
percentage of clot lysed after 30 min.
TEG interpretation Prolonged R Time =
↓ clotting factors – treat w/ FFP
TEG interpretation Low MA =
↓ platelets – give platelets
TEG interpretation Prolonged K Time and/or low α angle =
↓ fibrinongen – treat w/ cryoprecipitate
TEG interpretation High LY30 =
↑ fibrinolysis – treat w/ antifibrinolytics (aminocaproic acid)
Hemophilia A
Factor VIII/antihemophiliac deficiency
Hemophilia B
Factor IX/Christmas deficiency
Hemophila C
Factor XI/Rosenthal deficiency)
Fibrinogen deficiency
Factor I
Prothrombin deficiency
Factor II
Sickle cell
Hgb S is a variant Hgb produced by substitution of valine for glutamic acid in position 6 of the beta chain due to a defect on chromosome 11
Premature Infant EBV
90-100 mL/kg
Parturient EBV
100 mL/Kg
Full-term Newborn Infant EBV
80-90 mL/kg
Infant 3 mo – 3 yrs of age EBV
75-80 mL/kg
Children > 6 yrs EBV
•65-70 mL/kg
Males EBV
75 mL/kg
Females EBV
65 mL/kg
Obese EBV
45-55 mL/kg
ABL=
EBV x (Original Hct – target Hct)/Original Hct
How much does one unit of platelets (250ml) raise the platelet count?
• 30,000-60,000/uL
How much does 1 unit of PRC increase hematocrit?
1g hct 3%
Identify the condition
Polycythermia Vera
