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

Appendix II Citrate anticoagulants and the avoidance of citrate toxicity

Based on studies undertaken in 1989–1990 (personal communication, M Gesinde), the following recommendations can be made to avoid citrate toxicity during apheresis procedures.

AII.1 Intermittent flow cell separator machines

The reinfusion rate of citrated blood or plasma should not exceed 0.015 mmol citrate/kg/min.

AII.2 Continuous flow cell separator machines

The continuous reinfusion rate of citrated blood or plasma should not exceed 0.01 mmol
citrate/kg/min.

AII.3 Maximum acceptable reinfusion rates (mL/min for a 70 kg donor)

For the four citrate anticoagulants that are commonly used in the UK, recommendations are represented in Table 3.2.

Table 3.2 Citrate anticoagulants

        Plasma Whole blood
AC AC:blood ratio Average plasma citrate (mmol/L) AC volume in collected plasma (%) Int. Cont. Int. Cont.

CPD-50

1+15(1:16)

17

11

60

33

100

60

Acid CPD

1+11(1:12)

19

14

55

29

90

50

ACD-A

1+11(1:12)

16

14

60

33

100

55

ACD-A

1+7(1:8)

23

20

45

24

75

40

AC = anticoagulant, Int. = intermittent flow cell separator, Cont. = continuous flow cell separator

Packed cells may be reinfused as quickly as the characteristics of the return system and the viscosity will allow, but not normally faster than 130 mL/min.

Note: For donors weighing less than 70 kg, these reinfusion rates need to be suitably adjusted downwards to avoid citrate toxicity occurring. They may also be adjusted upwards for donors above 70 kg in weight.

If anticoagulant formulations or ratios other than those represented above are used, the procedure should be validated to ensure:

  •  plasma citrate levels are within the required range for fractionation purposes, i.e. 15–25 mmol/L
     
  •  the citrate molar reinfusion rate does not exceed these recommended maximum acceptable limits.

Final collection volume must not exceed 15% TBV (excluding anticoagulant).