2018B06 Outline the adverse effects which could occur following the rapid transfusion
of ten units of packed red cells.

 

List:

·        Introduction

·        Storage lesion

·        Overload

·        Dilution

·        Metabolic

·        Immune

·        Infective

 

Introduction:

Red cell unit contents

·  Red cells

·  Small volume plasma

·  Preservative: sodium, adenine, glucose, mannitol

Massive transfusion

·  50% blood volume in 4 hours, or 100% of BV in 24 hours

·  10 units = 2.5L = 50% blood volume

Ideal ratio of RBC:FFP:plt

·  1:1:1 units = 4:2*:1 bags

·  May be situation-dependent

(*4 in Victoria)

Lethal triad

·  Acidosis

·  Hypothermia

·  Coagulopathy

 

Storage lesion: (at 4°C for 35 days)

Cells

·  Red cells: spheroidal, rigid, fragile; 25% loss at 4/52
(free Hb 1 -> 30mcg/mL)

·  White cells: inactivate but still antigenic

·  Platelets: inactivated at 48 hours?

Coag factors

·  Minimal since plasma removed

·  FV 50% at 3/52

·  FVIII 30% at 3/52

Metabolic

·  Temp 4°C

·  pH 7.4->6.7 (due to additives)

·  K+ 4->30mM

·  Ca2+ 2mmol/L -> ? (due to 3mg citrate)

·  ATP 75%

·  [2,3-DPG]: 50% at 2/52, 5% at 4/52 (due to low temp)

·  ↑Free haemoglobin

 

Overload:

Fluid

·  ↑Blood volume -> ↑preload

·  May cause heart failure

·  High risk if LV impairment

Iron

·  Haemolysis -> Hb breakdown -> ↑free haemoglobin

·  Risk of haemochromatosis -> damage to liver, pancreas, heart, pituitary

Microaggregates

·  Microvascular occlusion -> multi-organ dysfunction (especially lung)

 

Dilution:

Coag factors

·  Dilutional coagulopathy

o  Coag factors esp fibrinogen

o  Platelets

Plasma

·  Hyperviscosity

o  ↑risk thromboembolism

o  ↑resistance to flow, ↑myocardial work

 

Metabolic:

↓Temperature

·  Arrest if rapid via CVC

·  Coagulopathy

↓pH

·  Arrest if rapid via CVC

·  Negative inotropy

·  Generalized metabolic dysfunction

↑K+

·  Arrhythmia, arrest if rapid via CVC

·  Most K+ taken up by RBC upon transfusion

↓Ca2+

·  Arrhythmia, muscle weakness

·  (Note hypocalcaemia severe enough to cause coagulopathy would already have caused cardiac arrest)

↓2,3-DPG

·  Left shift oxyhaemoglobin dissociation curve -> ↓tissue oxygenation

 

Immunological:

Acute

·  Febrile non-haemolytic (cytokines)

·  Febrile haemolytic (incompatibility)

o   ABO: intravascular (DIC, renal failure, death)

o   RhD: extravascular (haemolysis)

·  Anaphylaxis (Type 1 hypersensitivity against plasma protein)

·  TRALI (? donor antibody ? host priming by illness)

Delayed

·  Alloimmunisation

o   Delayed haemolysis (anamnestic response to Kell, Kidd, Duffy)

o   Haemolytic disease of the newborn (anti-RhD IgG crosses placenta)

o   Post-transfusion purpura (anti-platelet antibody -> consumption)

·  Cancer recurrence (immune suppression)

·  Graft vs host (donor WBC multiplies in immunocompromised host)

 

Infective:

Bacteria

·  Platelets (room temp) > RBC

·  Certain bacteria can multiply in the cold

Viruses

·  HBV, HCV, HIV; CMV

Other

·  Parasites (e.g. P.falciparum malaria)

·  Prion

 

 

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