Blood groups and transfusion reactions Flashcards
Describe the three responses to blood loss
Vascular Spasm
Platelet plug formation
Coagulation
Describe the process of erythropoesis
Is the production of red blood cells
Describe the function of the SNS to significant blood loss
Increase the production of red blood cells
Production of adrenaline
Constrict veins increasing venous return, cardiac preload and cardiac output
Constrict arterioles increasing peripheral resistance and BP
Release of aldosterone and antidiuretic hormone
Define the term antigen
a substance that is recognised as foreign by the immune system & generates an immune response
Using the ABO classification name the four main blood groups and state what antigens each blood group has
A - Antigen A
B - Antigen B
AB - Antigen AB
O - no antigens
For each of the four blood groups state what antibodies would be present in the plasma
A - Antibody B
B - Antibody A
AB - No antibodies
O - Antibody A&B
State the blood type for universal recipients & explain why this type can receive blood from all blood groups
AB positive is the blood type for universal recipients as they do not have A, B or D antibodies in their blood plasma. Therefore not causing a reaction
State the blood type that is called the universal donor and explain why this blood type can donate to all blood groups
O negative is the universal donor as they do not have A, B or D antigens and so have A & B antibodies. Therefore not causing a reaction
Explain the difference between blood typing & cross-matching
Blood typing is determining a persons blood type whereas cross matching is matching donor blood with recipient blood to check for compatibility.
List the six different types of blood transfusion reactions
Acute Haemolytic Febrile Mild allergic Anaphylatic & severe allergy Circulatory overload Sepsis
Describe what causes a febrile reaction
Sensitization to to donors leucocytes, platelets or plasma proteins
Describe the clinical signs & symptoms you would observe if a person had a circulatory overload reaction
Cough, dysponea (rash) pulmonary congestion, headache, hypertension, tachycardia, distended neck veins.
Describe the two major physiological events that occur during an acute haemolytic reaction
Agglutination - obstruction of blood capillaries as red blood cells clump together
Haemolysis is the red blood cell rupturing causing haemoglobin to be released into the blood causing an obstruction.
Explain why a haemolytic reaction reaction is so severe
It is sever because the recipients antibodies will produce antibodies in huge numbers and attack the donors red blood cells
