JPAC Joint United Kingdom (UK) Blood Transfusion and Tissue Transplantation Services Professional Advisory Committee

6.2: Setting and maintaining specifications

The wide variability of the source material from which blood components are prepared makes it difficult to set stringent limits. Nevertheless, realistic minimum specifications should be set and complied with. Table 6.1 Discard limits

Blood component Parameter LOWER Limit (less than) UPPER Limit (more than)
Red Cells in Additive Solution, Leucocyte Depleted Haemoglobin (g/unit) 30  
Volume (mL) None 375
Red Cells for Intrauterine Transfusion, Leucocyte Depleted Haemoglobin (g/unit) 30  
Volume (mL) 150 350
Haematocrit (L/L) 0.70 0.85
Red Cells for Exchange Transfusion (not Whole Blood), Leucocyte Depleted Haemoglobin (g/unit) 30  
Volume (mL) 220 420
Haematocrit (L/L) 0.5 0.60
Red Cells in Additive Solution for Neonates and infants, Leucocyte Depleted Haemoglobin (g/unit) 30 prior to splitting none
Red Cells, Washed, Leucocyte Depleted Residual Protein (g/unit) none 0.5
Platelets, Pooled Buffy Coat Derived, Leucocyte Depleted Platelet yield (×109/unit) 160  
Volume (mL) 150 380
Platelets, Apheresis, Leucocyte Depleted Platelet yield (×109/unit) 160  
Volume (mL) 150 380
Platelets for Intrauterine Transfusion, Leucocyte Depleted Volume (mL) 50 120
WBC (x10/unit) none 2.5
Fresh Frozen Plasma, Leucocyte Depleted Volume (mL) 200 360
Factor VIII(IU/mL) 0.3 none

Discard limits are also set for certain components that are subject to non-destructive quality monitoring, such that components that are excessively out of specification are not used therapeutically (Table 6.1). Component and process quality monitoring results should be subjected to statistical analysis so that trends can be identified. Guidance on appropriate approaches to statistical process monitoring is given in the Council of Europe guide,2 and in Beckman et al. (2009).3 A flowchart adapted from Beckman et al., to aid in selection of appropriate methods, is reproduced as Figure 6.1. If the results of analyses show a consistent trend towards the minimum requirements specified in Chapter 7, the cause should be investigated. The criteria to be investigated must be detailed in the relevant SOP together with the corrective action to be taken. The steps to be considered should include the following:

  • An investigation of the collection, testing, production and distribution procedures as appropriate.
     
  • Checking that procedures are up to date and are not being deviated from.
     
  • Checking the operation of equipment and storage conditions (this may include reviewing validation documentation and/or revalidation).

The person responsible for quality assurance and/or production may initiate investigations beyond the scope of written procedures.