Transfusions and Blood Types

• Cardiovascular system minimizes the effects of blood loss by:

  1. reducing volume of affected blood vessels
  2. stepping up production of red blood cells
• Whole blood transfusions don't usually happen but infusions of packed red blood cells is used.
• antigens: anything the body perceives as foreign

  • highly specific glycoproteins and glycolipids on body cells that identify us
• ABO blood groups: presence or absence of A and B agglutinogens
• O blood group have neither agglutinogen

  • most common in the US
  • universal donor
• AB blood group has both antigens

  • least common in US
  • universal recipient
• Rh factor: Rh agglutinogens

  • C,D,E,e,c are fairly common
  • 85 percent of Americans are Rh+
  • if an Rh+ receives a Rh- antigen body will start synthesizing the other antigen,vice versa
• transfusion reaction: recipients plasma antibodies attack the donor's red blood cells

  • agglutination of foreign red blood cells clogs small blood vessels
  • clumped red blood cells rupture or are phagocytized and hemoglobin is released
• transfusion reaction effects:

  • transfused blood cells can not transport oxygen
  • clumped red blood cells in small vessels hinder blood flow to tissue
  • circulating hemoglobin passes freely into kidney tubules causing cell death and kidney shut down
  • fever, chills, low blood pressure, rapid heartbeat, nausea, vomiting and general toxicity
• cross matching: shows whether the donor and recipient are compatible
• autologous transfusions: patients will donate their blood in advance
• replacing lost blood volume is replacing isotonic salt solution iwth normal saline or multiple electrolyte solution

  • restores but not oxygen carrying ability
• differential white blood cell count: determines the relative proportions of individual leukocyte types
• pothrombin time: how well blood can clot

  platelet count: when thrombocytopenia is suspected
• Comprehensive Metabolic Panel: a blood chemistry profile that measures carious electrolytes, glucose, and markers of liver and kidney disorders
• complete blood count: different ypes of formed elements, hematocrit, measurements of hemoglobin content and size of RBCs