Blood Transfusions and Blood Typing

1. Transfusion of Blood
1. whole blood transfusion - all cells and plasma; anticoagulants (citrate and oxalate salts) used
2. packed red blood cells - most of the plasma has been removed prior to transfusion
2. Human Blood Groups
   

1. Agglutinogens - glycoproteins on the surface of blood cells; causes "agglutination" (clumping)
2. ABO Blood Groups - determined by presence or absence of Type A and Type B agglutinogen proteins on cell membrane
   

• TYPE GENES PEOPLE Antibodies Receive Blood from:
  

• type A A/A, A/O, O/A (30-40%) Anti-B A, O
• type B B/B, B/O, O/B (10-30%) Anti-A B, O
• type AB A/B or B/A (3-5%) none A, B, AB, O
• type O no A or B (40-50%) Anti-A,Anti-B O only
  

3. Agglutinins - antibodies against either A or B agglutinogen (whichever is not present)
   

• transfusion reaction - patient's antibodies attack the donor blood
• A (anti-B) receives A,O (not B)
• B (anti-A) receives B,O (not A)
• AB (none) receives A, B, AB, O universal recipient
• O (anti-A,anti-B) receives O universal donor
• agglutination - when incorrect blood transfused, antibodies will "clump" new blood
• hemolysis - after clumping, RBCs may rupture, releasing hemoglobin, harming kidney
• dilute hemoglobin, administer diuretics
  

4. Rh factor - a different group of agglutinogens
   

• Rh positive (Rh+) - an Rh factor is present
• Rh negative (Rh-) - NO Rh factor
• transfusion reaction - delayed and less severe than in ABO confrontation
• erythroblastosis fetalis - Rh- mother antibodies attack Rh+ of older newborn; results in anemia and low oxygen levels (hypoxia)
• RhoGAM - serum with anti-Rh agglutinins which will clump the Rh factor, blocking the reaction of mothers antibodies
• exchange transfusion - directly from the mother (Rh-) to the newborn (Rh+)
  

5. Blood Typing - mixing Donors Blood with Recipient Antibodies (Anti-A, Anti-B, anti-Rh) in order to identify agglutination
   
6. Expanding Blood Volume to Avoid Shock
   

• pure plasma without antibodies
• plasma expanders - purified human serum albumin, plasminate, dextran
• isotonic saline - normal electrolyte solution isotonic to blood plasma (Ringer's Solution)
  

7. Diagnostic Blood Tests
   

• anemia - low hematocrit (below 35%)
• lipidemia - high in fat; yellowish plasma
• diabetes - blood glucose level
• infection - generally higher WBC count
• leukemia - significantly higher WBC count
• differential WBC count - counts % of each of the different leukocytes (helps diagnose)
• prothrombin time - time for clotting to occur
• platelet count - diagnose thrombocytopenia
• complete blood count - overall blood review

Category: Pathology Notes