Q4iii: The changes in stored whole blood

  • Whole blood = contains: RBC, WBC, platelets, plasma, proteins, coagulation factors, electrolytes, dissolved gases
  • Presented with CPDA1
    • Citrate = chelates Ca2+ (anticoag)
    • Phosphate = Pi for ATP
    • Dextrose = E substrate
    • Adenosine = ATP substrate

Storage

  • 4°C
  • Slows cellular metabolism
  • ↓bacterial growth
  • Lasts 35 days

Whole Blood Changes

RBC

  • ↓2,3 DPG → L) shift ODC → ↑Hb-O2 affinity
  • Loss of membrane integrity (failure Na/K/ATPase) → spherical + rigid
  • K+ leaks out of cells
  • ↑lactate
  • Some cells die & haemolyse
  • To quantify for shelf life ≥ 70% RBC must be viable at 24hrs

WDC

  • Become non functional in 24hrs storage
  • But still antigenic

Platelets

  • None after 48hrs
  • Massive TF causes dilutional thrombocytopaenia

Coagulation Factors

  • V & VIII are most labile
  • 5 = 50% ↓ 14 days
  • 8 = 50% ↓ 1 day

Biochemical

  • ↓pH = no liver to clear lactate; RBC no mitochondria (anaerobic metabolism)
  • ↓glucose
  • ↑K+ = progressive impairment Na/K/ATPase
  • ↓ATP

Bacteria

  • 3/1000 contaminated
  • Pseudomonas can grow at 4°C
Bacteria