Blood group inheritance and transfusion immunology - 2

Question 1

HDN - diagnosis

Answer 1

• screen blood type, Rh status, presence of anti-Rh-D Abs

Question 2

HDN - treatment

Answer 2

• after birth : mainly transfusion
• before birth : intrauterine transfusion every 1 or 2 weeks till foetal lungs are matured

Question 3

HDN - prevention

Answer 3

• give anti-Rh-D immunoglobulin within 72hr after delivery

Question 4

HDN - complications

Answer 4

• before birth : foetal aneamia, death
• after birth : haemolytic anaemia, liver damage, heart failure

Question 5

indications of blood transfusions

Answer 5

• haemorrhage
• loss of one component of blood

Question 6

categories of blood transfusions

Answer 6

• whole blood - blood replacement in e.g. surgeries
• plasma - to treat coagulopathy
• platelets - together with plasma to treat or prevent bleeding
• RBCs - in intra-operative bleeding with low Hb levels
• cryoprecipitate - rich source of fibrinogen used e.g. for treating or preventing bleeding in patients with low fibrinogen

Question 7

types of transfusions

Answer 7

• heterologous : blood from another person
• autologous : blood from same person

High proportion of patients are not eligible for autologous, including those with acute or chronic anaemia, or active infection and those needing emergency surgery)

autologous is safest method but needs advanced planning

Question 8

complications of blood transfusion

Answer 8

• acute haemolysis
• acute renal failure ( haemolysis - haemoglobulinaemia - proximal tubule injury - acute tubular necrosis )
• acute bacterial infections
• septic shock
• electrolyte imbalance (only in massive transfusions)

Question 9

general guidelines on safe blood transfusion

Answer 9

• determine ABO & Rh-D blood types
• perform cross match for atypical Abs
• ensure blood is a safe, monitored and temp controlled place
• ensure notes are adhered properly so transfusion for the right patients

Question 10

blood typing - forward typing

Answer 10

• involves testing for Ags on patients RBCs
• venous blood obtained from patient
• patient’s RBCs seperately treated w known sere containing Abs to RBC Ags
• blood type determined upon clumping of RBCs with particular serum

Question 11

blood typing - reverse typing

Answer 11

• involves testing for Abs in patients serum
• patient’s serum added to blood known to be type A and B
• patient’s blood type determined based on serum Abs

Question 12

cross matching

Answer 12

• once blood type is determined, donor blood of same ABO and Rh type is chosen
• donor’s RBCs are mixed with patient’s serum
• if no agglutination, blood is safe for transfusion