BLOOD TRANSFUSION Flashcards
WHAT IS A BLOOD TRANSFUSION?
A Blood Transfusion is the infusion of whole blood or blood component such as plasma, red blood cells, or
platelets into the patient’s venous circulation
A blood transfusion is given because of blood or red blood cell loss, such as hemorrhage in trauma,
operation, anaemia, or when the body is not adequately producing cells such as platelets.
The person receiving the blood is the Recipient.
The person giving the blood is the Donor
LIST THE MAIN BLOOD GROUPS
Blood is classified into 4 main groups (A, B, AB, and O)
RELATE THE BLOOD GROUPS TO THEIR ANTIGENS
A antigen or agglutinogen is present on the RBCs blood
group A ,
B antigen is present in people with blood group B, and
Both A and B antigens are found on the RBC surface in group AB blood.
Neither antigen is present in people with group O blood
EXPLAIN TH RH SYSTEM OF BLOOD TRANSFUSION
The Rhesus (Rh) System
Another antigen to be considered always is - the Rh antigen.
Rh factor is an inherited antigen in human blood.
Bld that contains the Rh factor is known as Rh-positive, if group A has it, its classed as A+ (or A positive).
When it is present in bld gp B, is said to be Rh-positive, if gp B does not have, its called B- (or B negative)
Rh blood does not naturally contain Rh antibodies.
If Rh-positive blood is injected into an Rh-negative person, the recipient gets sensitized and develops Rh
antibodies, called sensitisation
Subsequent transfusion with Rh-positive blood may cause serious reactions with clumping and hemolysis of
red blood cells.
EXPLAIN CROSS MATCHING
The process of determining compatibility between blood specimens is Cross matching.
RBCs from the donor blood are mixed with serum from the recipient, a reagent (Coombs’ serum) is
added, and the mixture is examined for visible agglutination.
If no antibodies to the donated RBCs are present in the recipient’s serum, agglutination does not occur
and the risk of transfusion reaction is small
WHAT ARE THE PRIMARY TESTS AS RECOMMENDED BY WHO THAT NEED TO BE CARRIED OUT IN ORDER TO PROCEED WITH A BLOOD TRANSFUSION?
Primary tests recommended by WHO before BT are the following:
1. Surface antigen for hepatitis B (HbsAg)
2. Antibody to Hepatitis C
3. HIV antibody (Subtypes 1 & 2)
4. Serology tests for Syphilis
LIST ALL THE TESTS PRIOR TO A BLOOD TRANSFUSION WHETHER PRIMARY OR ON A LOCAL NEED BASIS
Primary tests recommended by WHO before BT are the following:
1. Surface antigen for hepatitis B (HbsAg)
2. Antibody to Hepatitis C
3. HIV antibody (Subtypes 1 & 2)
4. Serology tests for Syphilis
Other tests carried out depending on local need:
1. Prion diseases – Creutzfeldt Jacob Disease
2. Cytomegalovirus
3. HIV Nucleic acid test (p24)
Also mandatory that the donor should be free from fever a fortnight before donating blood.
Also should be free from parasitic diseases like Malaria and Filariasis.
WHAT ARE THE INDICATIONS FOR A BLOOD TRANSFUSION?
(b) Indications
1. Acute blood loss – Due to Trauma, operation
2. Chronic Anemia
3. Major operative procedures
4. As a Prophylactic measure to Surgery
5. Severe Burns
6. Blood Dyscariasis
EXPLAIN THE BLOOD TRANSFUSION PRINCIPLES FOR CHRONIC ANEMIA
Transfuse only to decrease symptoms (decompensated state) and to minimize
risk (generally at Hb of less than 7g /dL).
-Do not transfuse above 7g/dL Hb unless patient is symptomatic.Treat
nutritional and mild blood loss anemia with specific therapeutic agents as
indicated (iron, folic acid, B12)
WHAT IS MEANT BY TRANSFUSION TRIGGER?
Transfusion Trigger
* The decision to transfuse any patient for a given indication must balance the risks of not transfusing.
* RBC transfusion is not indicated when Hb>10g/dl
WHAT CRITERIA NEED TO BE MET FOR A BLOOD TRANSFUSION?
Transfuse Criteria
- < 6g/dl - Benefit from Transfusion
- 6 - 8g/dl - Unlikely to benefit – absence of bleeding
- > 8g/d l - Not indicated
WHAT ARE THE RED BLOOD CELL TRANSFUSION GUIDLINES?
Red Blood Cell Transfusion Guidelines
Acute and Perioperative Blood Loss
a) Estimate blood loss
-If > 30-40% of rapid blood loss: transfuse RBCs and use volume expanders
-If < 30-40% of rapid blood loss: RBCs not usually needed in otherwise healthy person
b) Monitor vital signs; Tachycardia and hypotension, if not corrected with volume expanders: RBCs needed
c) Measure haemoglobin
-If Hb > 10 g/dL: RBCs rarely needed
-If Hb < 7 g/dL: RBCs usually needed
-If Hb 7-10 g/dL: RBCs may be needed, determined by additional clinical conditions
d) Hematocrit trigger point for transfusion is <21%.
e) For cardiac disease patients, threshold goes up to Hb <10gm% and hematocrit <30%
WHAT ARE THE BLOOD TRANSFUSION GUIDELINES FOR A PEDIATRIC PT?
Guidelines for Paediatric Transfusion
a. If Hb is < 4 g/dL, transfuse.
b. If Hb is > 4 g/dL and < 5 g/dL, transfuse when signs of respiratory distress or cardiac failure are present. If
patient is clinically stable, monitor closely and treat the cause of the anaemia.
c. If Hb is > 5 g/dL, transfusion is usually not necessary. Consider transfusion in cases of shock or severe
burns. Otherwise, treat the cause of the underlying anaemia.
d. Transfuse with 10 to 15 ml/kg of PRBCs or 20 ml/kg of whole blood.
e. In presence of profound anaemia or very high malaria parasitaemia, a
higher amount may be needed.
LIST THE COMPLICATIONS FOR A BLOOD TRANSFUSION
(c) Complications
i. CCF
ii. Air embolism
iii. BT RXN
a) Incompatibility
b) Simple pyrexia RXNs
c) Allergic RXNs
d) Immunological sensitization
e) Sensitization to leucocytes, platelets
iv. Infections due to
a. Serum hepatitis (HBV, HCV)
b. Site of cannula- bacteria
c. HIV
d. Malaria
e. Cytomegalovirus
f. Parasitic diseases – Malaria, Filariasis and Chaga’s disease.
g. Bacterial Contamination: common with platelet transfusions, e.g. Gram negative Yersinia
enterocolitica is the most common cause of fatal sepsis, syphilis
