Chapter 3: Blood Flashcards
Proerythroblast
precursor for erythrocyte (with large nucleus)- produced in long bone marrow?
Erythropoietin
hormone (found in kidney/liver) that stimulates RBC production in bone marrow. Vit. B12 and folic acid are important in producing mature RBC
Aplastic Anemia
if bone marrow does not produce enough RBC
Pernicious Anemia
lack of Vit. B12 and folic acid in diet or poor absorption= low RBC
Hemoglobin
in RBC, function to transport oxygen/CO2
- iron and protein compound
- each heme molecule carries 1 O2
Polycythemia
elevated hematocrit (could be caused by living in high elevation, pulmonary disease, etc)
Anemia
low RBC count (could be caused by blood loss, RBC production failure, or RBC destruction)
Hematocrit on Bypass
22-30% considered normal on bypass (lowers because of dilution- which provides better capillary perfusion)
Hemolysis
destruction of RBC membrane- release hemoglobin
- creates plasma free hemoglobin and releases the intracellular K
- if occlusion is too loose= turbulence (Reynolds Number > 2,000)
- they want laminar flow
- best way to set occlusion- column of arterial fluid 30 inches above roller head, tighten until it drops 1 cm per minute
Diapedesis
passage of WBC through the walls of blood vessels
WBCs are characterized by:
presence or lack of granules in cytoplasm
1) granulocytes contain granules (neutrophils 60%, basophils 1%, eosinophils 3%)
2)agranulocytes lack granules ( lymphocytes 30%, monocytes 6%)
Order: N L M E B
Leukocytosis
increased WBC count (normally with infection)
-above 5,000-10,000 per cubic millimeter
Leukopenia
abnormal decrease in WBC count (could be caused by drug reaction, radiation, etc)
-below 5,000-10,000 per cubic millimeter
Neutrophils
- granulocytes, produced by bone marrow
- engulf (phagocytosis) foreign bodies
- remove bacteria, cell debris, solid particles
- can move from capillary to tissue
Neutrophilia
increase in neutorphils (above 7500 per cubic millimeter)
Neutropenia
low neutrophil count (below 1,500 per cubic mm)
- linked to leukemia, infections, low b12, chemotherapy)
- also more likely to contract infections
Eosinophils
- granulocytes, 2 lobed WBC
- increase with allergies and parasites
Eosinophilia
increase in eosinophils (> 500 per cubic mm)
-Hyperesoinophilia- increase due to no apparent cause
Basophils
- granulocytes, contain nucleus and granules
- release heparin and histamines to keep vessels open at sites of pathogens
- only 1% of WBC!
Basophilia
increase number in basophils (>100 per cubic mm)
-numbers increase with bone marrow disease and decrease with severe allergic reactions
Monocytes
- become macrophages when leave blood stream and enter tissue- engulf pathogens and foreign particles
- they arrive second to site after neutrophils
- largest WBC
Lymphocytes
production of antibodies (B and T cells)
Lymphocytosis
increase in lymphocytes >4,500 per cubic mm
Lymphocytopenia
decrease in lymphocytes < 1500 per cubic mm
B Cells and T Cells
lymphocytes
- B cells- exposed to antigen/allergen, moves to spleen/lymph nodes and produces plasma/memory cells
- T cells- killer cells, assist B cells and secrete chemicals
Platelets/thrombocytes
- no nucleus or hemoglobin, surface negatively charged, produced in bone marrow (megakaryocytes) as broken fragments of cytoplasm
- necessary for clotting
- –phospholipid membrane aids in clotting factors= platelet factor 3
- –releases vasoconstrictor= thromboxane A2
- -DO NOT give platelets on bypass
- normal count is 150,000-350,000 per cubic mm
- count decreases 20-65% after CPB
Thrombocytopenia
-low platelet count (<50,000)
Cell suffix (number wise)
- philia
- cytosis
- penia
philia- increase
cytosis- increase
penia- decrease
Plasma
- 91.5% water and comprises 55% of blood
- mostly comprised of albumin and plasma proteins
- function is to transport blood cells, platelets
- contains electrolytes, clotting factors, proteins glucose, fats, bilirubin, globulins, and gases
- very important for protein balance between interstitial space (colloid osmotic pressure)
Plasmapheresis and Plateletpheresis
separation of plasma or platelets from blood and returned to body
Potassium
- intracellular (98% of total K is intracellular)
- needed for cardiac muscle contractions
- insulin brings K and glucose into the cell (insulin levels are low during hypothermic bypass, so blood glucose/K increases)
- if K is high AND not peeing, consider giving insulin
- hyperkalemia will cause irregular heart contractions
- Normal K levels are 3.5-5 mEq/L
Calcium
- contractility, clotting, neurotransmission
- blood calcium is regulated by parathyroid hormone and Vit D
Magnesium
- intracellular
- competes with calcium
- controlled by kidney
3 Phases to Forming a Clot
1) vascular- constriction of vessels at injury
2) platelet aggregate and release factors to aid in vasoconstriction
3) clotting factors/cascade
Intrinsic vs. Extrinsic Pathway
- intrinsic= initiated by foreign substance
- extrinsic= initiated by tissue injury
- both combine into the common pathway with Factor X
Heparin
- increases antithrombin 3 (which inactive- stops production of thrombin)
- –stops fibrinogen from becoming fibrin and prothrombin from becoming thrombin
- also binds to cofactor 2 to inactivate thrombin
- half-life= 1-2 hours (increased during hypothermia, decreased during rewarming)
- elimination by kidneys (so impaired renal function can prolong heparin function)
- bolusing heparin at beginning of case can decrease SVR and BP by 10-20%
- bovine or porcine
Anti-thrombin III Deficienc
- if no response to initial heparin dose, redoes
- if no response, give 2 units of FFP or ATIII
Protamine
- binds to heparin to inhibit and allows clotting
- from salmon sperm
- 1-1.3 mg per 100 units of heparin given
- given slowly to prevent reactions (5 /min): hypotension, bradycardia, increase CVP/PAP (increase chance of reaction if DMI, seafood allergy, or past protamine exposure)
- shorter halflife than heparin- 5 min?
