Submitted by Dr LAU Chun Wing Arthur on 14 March 2009
Department of Intensive Care, PYNEH
You may know how to read the label of a bottle of red wine, but do you know how to read the label of a bag of packed red cells?
Click image to enlarge.
How is a bag of packed cells prepared? What is SAGM? What is TGA Standard? What are the meanings of the four little symbols? What is hidden behind the big labels?
What is SAGM?
SAGM is a combination of constituents as additive solution to give the red cell optimum viability. It actually stands for
- Sodium Chloride: provides isotonicity
- Adenine: maintains ATP for red cell viability
- Glucose: supports red cell metabolism
- Mannitol: helps reduce red cell lysis
Preservation of red cells in SAGM solution can keep the life of red cells to up to 42 days, longer than using CPD Solution and CPDA solution alone. Difference between CPD, CPDA-1 and SAGM can be found here.
Source: SURU International Pvt. Ltd.
What is TGA Standard?
TGA stands for "Therapeutic Goods Administration". From the Hong Kong Red Cross Blood Transfusion Service website, "The BTS has first achieved ISO9002:1994 Certification in 1999, followed by certification in 2002 by the Australian Therapeutic Goods Administration (TGA) for its cGMP accreditation with respects to its blood and component production."
How is a pack of red blood cells prepared?
The blood processing sequence is as follows:
1. Blood donation at Red Cross
2. Donors who weigh between 40-45kg will donate blood into a single bag containing CPD, which will be kept for used as whole blood. Donors who weigh 45kg or more will donate blood into a main bag connected with three other bags which are used for containing components including platelets, buffy coat (white cells + platelets) and plasma separated from the whole blood after collection. The final component left in the main bag is then the red cells, containing the additive solution SAGM plus the red cells left after centrifugation of the original whole blood with the CPD. This is called the Quadruple Blood Pack Unit. From the label, it is manufactured by JMS Singapore PTE Ltd.
Source: JMS brochure on blood bags
As a result, "packed cells" means that the red cells are packed together, not a pack of red cells!
Meanings of the four little symbols
There are medical device symbols used by the International Organizatin for Standardization (ISO).
The information corresponding to the requirements in the logos is to the right of them, but part of it is covered by a label. So what is behind?
The amount of CPD with its composition is revealed, together with the catalogue number (REF symbol), and all the manufacture and expiry dates. Details are shown below:
4. International Standard. ISO 15223-1, First Edition 2007-04-15, pages 5 - 6