L9-transfusion:indications And Regulations Flashcards
When do we need transfusion of whole blood
In cases of acute blood loss and shock
When do we need transfusion of packed red blood cells
In cases of chronic severe anemia or leukemia
When do we need transfusion of platelets concentrate
Indicated in cases of thrombocytopenia and bleeding due to platelets dysfunction
What does a transfusion reaction
▪️If a person is given blood of an incompatible type two different antigen antibody interactions take place
▪️Less important unless a large amount of blood is transfused
▪️ antibody interaction with retro side bound antigen may result in agglutination were hemolysis of the attacks red blood cells and this can lead to a transfusion reaction
What is blood typing
First step before blood transfusion
▪️It focuses on the antigens on the surface of the red cell this text finds out the blood type A,B,AB or O
also to find out if the blood RH type is negative or positive
How is blood typing performed
▪️The RBCs are first separated from the plasma and diluted with Saline solution
One portion is then mixed with anti a agglutinin and another portion is mixed with anti B agglutinin
▪️After seven minutes the mixtures are observed under a microscope if the RBCs have become clumped then an antibody antigen reaction has resulted
What is cross matching
Focuses on antibodies in the plasma
In a crossmatch, donor cells are mixed with the plasma of the recipient if antibodies exist in the recipient plasma to antigens on the red cells of the donor transfusion reactions can occur
Describe agglutination of RBCs
▪️When bloods are mismatched so that anti-A or anti-B plasma agglutinins are mixed with RBCs that contain A or B agglutinogens
▪️The RBCs agglutinate as a result of the agglutinins attaching themselves on the to the RBCs
▪️Because the agglutinins have 2 binding sites or 10 binding sites The agglutinin can attach to two or more RBCs at the same time thereby causing the cells to be bound together by the agglutinin
▪️This binding causes the cells to clump which is the process of agglutination
▪️These clumps plug small blood vessels throughout the circulatory system
▪️during the ensuing hours to days, physical distortion of the cells or attack by phagocytic white blood cells destroys the membranes of the agglutinated cells releasing hemoglobin into the plasma called hemolysis is of RBCs
What are the manifestations of transfusion reaction
Allergic reaction
circulatory overload
febrile reaction
transfusion transmitted infection hemolytic reaction
What happens during hemolytic reaction
All transfusion reactions eventually cause immediate hemolysis
Hemoglobin released from the RBCs is done converted by the phagocytes into Bilirubin and then excreted in the bile by the liver
▪️The concentration of bilirubin in the body fluids often rises enough to cause jaundice and the persons internal tissues and organs become Coloured with yellow bile pigment
▪️ If liver function is Normal the bile pigment will be excreted in the intestines by way of liver bile so Jaundice does not appear in adult unless more than 400 mL of blood or hemolyzed in less than a day
What does acute kidney failure after transfusion reactions
One of the most lethal effects of transfusion reactions is kidney failure
Can begin within few minutes to a few hours and continue until the person dies of acute renal failure
Why does delivery shut down an acute kidney failure
1-The antigen-antibody reaction of the transfusion reaction releases toxic substances from the hemolyze in blood that causes powerful renal vasoconstriction
2-Loss of circulating RBCs in the recipient along with the production of toxic substances from the Hemolyzed cells and immune reaction often causes circulatory shock the arterial blood pressure Falls very low and renal blood flow and renal blood flow and output dec
3-if total amount of free hemoglobin released in the circulating blood is greater than quantity that combined with the haptoglobin much of the excess leaks through a glomerular membrane into the kidney tubules
If hemoglobin concentration rises So high in the kidney tubules the hemoglobin precipitates and blocks many of the kidney tubules leading to Renal vasoconstriction, renal tubular blockage together cause acute renal shutdown
What is haptoglobin
Plasma proteins that bind small amounts of hemoglobin
