E2: Hematologic Systems Flashcards
What, in general, are the (2) changes that result in the increased Blood volume observed during pregnancy?
- Increased RBC Mass
- Increased ECF Vol.
What is the general pathway leading to Increased RBC mass?
Increased levels of human Chorionic Somatomammotropin & Prolactin triggers Erythropoiesis. This leads to increased RBC mass.
How is retention of H2O altered leading to Hypovolemia?
Several factors (Aldosterone, Estrogen, Prolactin, hPL, +) lead to increased Na+ & H2O retention. This leads to increased ECF Volume and thus increased Blood Volume.
What are the (8) general hematological changes during pregnancy?
- Increased Plasma Vol. & Hemodilution
- Increased Hb levels (but physiological anemia)
- Increased Coagulation factors (except factors XI, XIII, & ATIII)
- Hypercoagulable state
- Increased Iron absorption in gut
- Increased Iron binding capacity but Decreased S. Iron
- Decreased RBC count
- Decreased Fibrinolytic Activity
- Decreased Platelet Count
What are the important functions of pregancy-induced Hypervolemia?
- Meet metabolic/ Nutrient demands of;
- Enlarged uterus & hypertrophied vascular system
- Rapidly growing Fetus & Placenta
- Protection of the mother and (in turn) the fetus against effects of impaired venous return in the supine & erect positions
- Protection of the mother against blood loss during child birth
How does the Plasma Volume change during PostPartum?
- Decrease @ Delivery
- Increases again 2-5 days later
- 10-15% above baseline @ 3Weeks
- Return to Baseline @ 6Weeks
What does whole blood consist of?
Whole blood:
- Blood Plasma Plasma (55%)
- Formed Elements (45%)
Describe the general constituents of blood plasma
Blood Plasma;
- Water (91.5%)
- Plasma Proteins (7%)
- Other Solutes (1.5%)
Describe the function of Plasma proteins and the major ones mentioned here.
Plasma Proteins, in general, are important for;
- Contributing to blood viscosity
- Transportation (Hydrophobic moelcules, Calcium, etc)
- Regulation of Blood pH
General types;
- Albumins: Helps maintain osmotic Pressure
- Globulins: Ig’s are part of Immune System; a & B-globulins transport iron, lipids, and fat-soluble vitamins
- Fibrinogen: Role in Blood Clotting
Other Solutes consists of what general categories?
Other Solutes (1.5%);
- Electrolytes: Helps maintain osmotic pressure
- Nutrients (metabolic molecules)
- Gases (O2, CO2, N2)
- Reg. substances (Enzymes, hormones, vitamins, etc.)
- Waste products (Urea, uric acid, creatine, creatinine, bilirubin)
What are the types of Formed Elements discussed?
Formed Elements;
- Platelets
- Erythrocytes
- Leukocytes;
- Neutrophils
- Lymphocytes
- Monocytes
- Eosinophils
- Basophils
What is the change in Erythropoietin levels during pregnancy?
Erythropoietin levels increase by 50%
Describe the change in Erythrocytes during pregnancy.
Erythrocytes levels increase by 20-30% (250-450ml) w/ iron-supplemented during pregnancy (15-20% non-iron). It is a slow, continuous increase starting at the 1st Trimester & MAY accelerate in the 3rd.
Erythrocyte mass increases as well
The increase is stimulated by;
- Increased Erythropoietin
- hPL, PRL, & Prog.
Describe the change in Erythrocytes in PP
50% of Erythrocytes are lost at birth.
Erythrocyte production temporarily ceases & remaining increased erythrocytes are lost through normal Catabolism.
Describe the changes in hematocrit during pregnancy
Hematocrit levels decrease 3-5% to 33.8% @ term. The decrease is due to hemodilution & is inversely proportional to Plasma Volume (lowest level in 2nd Tri.)
