Teaching Clinic - Complications of Transfusion Flashcards
- Hepatitis B virus (HBV) surface Ag and nucleic acid
- Hepatitis C Virus (HCV) Ab and nucleic acid
- Human Immuno-deficiency Virus (HIV) types I and II Ab and Ag and HIV-1 nucleic acid
- Hepatitis E Virus (HEV) nucleic acid
- Human T-Lymphotropic Virus (HTLV) types I & II Ab
- Syphilis Ab
Normal procedures of transfusion
- Collection of blood donation
- Indications of blood transfusion
- Clinical procedures before transfusion
- Laboratory pre-transfusion compatibility tests
- Clinical procedures at transfusion
- Post-transfusion follow-up
Collection of blood donation
- Consent
- What is self-deferral?
- Is there risk of infection?
- What type of continuous follow-up is done?
- Voluntary donation
- Self-deferral (defer = delay [this person in the future might be able to donate blood again, i.e. infection, return from malaria-endemic country]
- Microbiological screening (not all infectious agents are screened)
- Microbiological cultures (not all infectious agents are screened)
- Continuous follow-up of donors (donor can call back blood transfusion service to inform them if they have developed Sx of infection after donation, i.e. diarrhoea = blood bank must notify the people who have received blood transfusion products so they can be screened for)
Companies can extract blood cells, immunoglobulins from donated blood
Some may their own sell blood for profit (source of blood is not entirely secure: usually poorer individuals, may have substance abuse issues)
- Indications of blood transfusion
- What are other alternatives to blood transfusions?
- Transfuse only when necessary
- Do not transfuse if there are other options
– Replacement of iron after bleeding
– erythropoietin in renal failure patients
– blood salvage strategies (collect blood and re-infuse back to patient)
– HIF stabiliser
– TBF-beta ligand binders
What are clinical procedures to perform before transfusion to prevent mix-up?
2D barcode wrist-band to identify patient!!!
If patient is known to be sensitive to certain blood products, we must take not of this! (give pre-medications to prevent transfusion reaction)
Laboratory pre-transfusion compatibility tests
- How are specimens identified?
- What do we type and screen?
Type: A group, B group, O group + Rhesus D (C, D, E = we only type D)
Screen for clinically significant antibodies in recipient’s blood (if antibodies are significant, they may lyse the donor blood)
What is the significance of auto-antibodies?
Auto-antibody:
◦ Positive IAT
◦ Antibody with broad specificity
◦ Formation: Due to auto-immunity
◦ May be drug induced
What is the significance of allo-antibodies?
Allo-antibody: Antibody formed against antigen not previously encountered
◦ Positive IAT
◦ Antibody with defined specificity against minor blood group
Formation due to previous pregnancies woman
◦ Formation due to previous blood transfusions
If patient has been transfused blood before from a patient with minor blood group antigen different than theirs, they will develop an allo-antibody
Woman for alloantibody:
◦ Previous infusion
◦ Previous pregnancies
Men:
◦ ONLY Previous infusions
What are the clinical procedures at transfusion to prevent mix-up?
Visual inspection of blood products: Plasma is clear (do not transfuse unit of blood that is TURBID)
Blood is refrigerated at 4ºC. If you infused a lot of packs of blood to patient, they will develop hypothermia. (warm the blood to 37ºC in blood bath)
Monitor S/E: BP, pulse, RR, body temperature
Donor went to Grand Hyatt. He ate a buffet. He was turned away from blood transfusion service. Why?
Blood is too lipaemic!
Plasma will look cloudly, but in reality, it’s just because of high lipid-content
People will not use it due to abnormal appearance! It will be a waste.
Plasma is red after patient drinks a lot of beetroot. Will we use it?
Beetroot dye changes colour of plasma to red.
Cannot rule out possibility that blood is lysed and has entered plasma. Due to inability to rule out that blood product has undergone haemolysis after infection, we will NOT use the blood product.
Plasma is green in colour. Patient drank a lot of green tea and beverages. Why? Should we use it?
Pigment from green tea/beverages change colour of plasma.
Don’t accept this blood due to risk of infection. Inspect appearance carefully!
Post-transfusion follow-up
1 unit of blood: 1g/L of rise in Hb
If donor is very small, but recipient is very big, the Hb won’t increase a lot.
If the donor is very big, but recipient is very small, the Hb will increase a lot.
After transfusing, we will expect that Hb will return to normal or rise. If the Hb fails to rise or normalise, underlying pathology causing blood loss is still ongoing (i.e. UGIB)
Acute & chronic complications of blood transfusions
What are acute transfusion reactions? What is the allergy developed to? What product most commonly causes infective transfusion reactions?
HLA is what causes allergy!!!
Platelets are kept in room temperature (if we freeze them, they lose their energy)
What are chronic transfusion complications related to iron? How many mL of blood contains 1 mg of iron?
- 2 mL of blood contains 1 mg of iron
- 500 mL of blood contains 250 mg iron
Average amount of menstrual blood loss (pure blood) is 16 mL
If you transfuse a man with one unit of blood, you are giving them the iron that they require for 8 months (250 mg iron)
What are chronic transfusion complications related to infections?
Current estimated risk of transmission of viral infections
What are other rare complications of transfusion?
Some bacteria may grow at 4ºC (Pseudomonas) = the plasma was turbid, nurse failed to check
Amyloid invasion into spleen has what appearance
Sago spleen (spleen amyloidosis)
