Effects of anticoagulants on packed cell volume measurement.

A comparison was made of different types of anticoagulants on packed cell volume determinations of canine, feline, rabbit, and human blood. It was found that the use of excessive amounts of anticoagulant alters the packed cell volume when measured by the standard centrifuge method. It was also found that the results vary significantly when different anticoagulants are used. The effects are not seen when the packed cell volume is indirectly measured using an electronic cell counter. A balanced combination of ethylenediaminetetraacetic acid salts ameliorates the concentration-dependent effects.