Blood transfusion

Workup

Product	Storage / Half-life	Notes	Indications
Packed red cells	280mls Stored at 2-6'C 35 days (normal red cell life is 120 days)	Additive solutions: suspend cells CAPD: citrate-adenine-phosphate-dextrose SAMG: saline-adenine-mannitol-glucose Dosing: 4ml/kg raises [Hb] by 1g/dl	Anaemia Restore circulatory volume Improve tissue oxygen perfusion (by maintaining oxygen carrying capacity)
Platelets	Stored at room temperature on agitator (prevents clumping) 5-7 day life	Platelets are pooled as one donation normally contains ~55 x10⁹Risk of infection Rhesus sensitisation	Thrombocytopenia < 50 x 10 ⁹DIC Post bypass / dysfunctional platelets
Cryoprecipitate / FFP	Stored at -30'C 12 month shelf-life	Factors V / VII are most labile to temperature Dosing: 10-15mls/kg	Reversal of warfarin Post massive transfusion DIC / loss of clotting factors
Human Albumin	4.5% or 20% solution		Ascities / portal hypertension Oedema due to hypoalbuminaemia Plasma expander

Complications of transfusion

Immediate
- Temperature changes - from pyrogens (from dead polymorphs, endotoxins)
- Immune reactions
  1. Type I: Immediate - Anaphylactic reaction
  2. Type II: Cytotoxic -
  3. Type IV: Delayed
- Infection - gram -ve organisms (coliforms, pseudomonas)
- Metabolic - hyperkalaemia (haemolysis); hypocalcaemia (citrate antocoagulation), acidosis
- Circulatory - hypervolaemia: massive transfusion reaction = "transfusion equalliny patient's blood volume within 24 hours"
- Bleeding diathesis - deficient in platelets (thrombocytopenia) and clotting factors
Delayed
- Sensitisation to antigens
- Infection from unscreened blood - HBV, HCV, HIV, CMV, syphilis, malaria
- Fe-overload: heart, pancreas

Management

Stop transfusion
Resuscitate
Repeat G+S
Perform direct anti-globulin test (Coomb's test) on post-transfusion sample; antibodies against surface antigens
Check for haemolysis (bili, K); DIC (FDPs, haemoglobinuria)
Blood cultures

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