hi all ,

during blood donation of a particular donor our blood collection monitor went out of order due to which we had to take blood assuming that it was done and the volume was not measured when the volume was measured afterwards it was more than 500 ml .There came a question in my mind that it had altered blood to anticoagulant ratio .Kindly tell me that how does it affect a blood unit and what should we do in this case

In the UK, the volume must be 450mL +/- 10%, so such a unit would be discarded.

Except in the US, some donor centers are using 500mL bags so I assume that 500+/- 10% would stand?

Except in the US, some donor centers are using 500mL bags so I assume that 500+/- 10% would stand?

I believe the +/- 10% rule (for whatever size bag you are using) is true, as clmergen has stated.

If you are drawing in 450 mL bags you need to discard the unit; if you use the 500 mL bags, you may use it.

but i would feel happy if you state reason why should it be discarded and what can it cause if transfused

Sonia,

As you questioned intially, the whole blood to anticoagulant ratio may be altered such that the anticoagulant properties are depleted therefore unable to anticoagulate causing potential clot formation in the unit of blood. As some of the other posters stated there is a +/- 10% range for the volume collected to anticoagulant ratio ( Anyone please let me know if this understanding is incorrect). Do you know how much more than 500 ml was in the bag? 10% of 500ml = 50 ml; so if your total volume is >550ml then the unit may not be usable as it would exceed the anticoagulant capacity.

it was about 20 ml more