Acid-citrate-dextrose
Acid-citrate-dextrose or acid-citrate-dextrose solution is any solution of citric acid, sodium citrate, and dextrose in water. It is mainly used as an anticoagulant to preserve blood specimens required for tissue typing. It is also used during procedures such as plasmapheresis instead of heparin.
Formulation
Two solutions are defined by the United States Pharmacopeia. They have the following properties:| Substance | ACD-A amount | ACD-B amount |
| Total Citrate | 20.59 to 22.75g | 12.37 to 13.67g |
| Dextrose | 23.28g to 25.73g | 13.96 to 15.44g |
| Sodium | 4.90g to 5.42g | 2.94 to 3.25g |
To make use:
| Substance | Amount for ACD-A | Amount for ACD-B |
| Citric acid, anhydrous | 7.3 g | 4.4 g |
| Sodium citrate, dihydrate | 22.0 g | 13.2 g |
| Dextrose, monohydrate | 24.5 g | 14.7 g |
| Water for injection to make | 1000 mL | 1000 mL |
Dissolve the ingredients and mix. Filter until clear.
History
Blood storage
ACD was invented by Loutit et al. in 1943 for preserving whole blood. They found that the mixture offers better red blood cell survival than the then state-of-the-art, MRC 1940. The old solution also caramelize when autoclaved, while the new one does not due to higher acidity. As a result, blood can now be stored for much longer, up to 21 days.ACD was developed into CPD in 1957, a version with phosphate added intended to reduce phosphate leakage from red blood cells. It does not improve shelf life appreciably, but patient recovery is improved. A later improvement was CPD with adenine, which boosted RBC survival to five weeks when combined with plastic bags. CPD, in combination with adenine-mannitol additives such as SAGM, is the current blood bank preservative as of 2012.
Although human blood is generally stored using newer formulations, the uptake of such technology is slower in veterinary medicine. From experimentation on horse and donkey blood, it does seem that the newer human-blood storage technogies also translate to improvements in animal blood storage.