[Changes in ionized calcium and citrate levels in dogs during mechanical autotransfusion with heparin, ACD and CPD].

The control of ionized calcium (Ca++), total calcium, and citrate levels in serum were determined in dogs during autotransfusion (AT) of blood stabilized with heparin, ACD (formula B) and CPD. Blood samples were taken according to the changes of aortic pressure (AOP), which was continuously monitored. Taking the values during the stable phase of AOP preceding the AT as baseline, Ca++ dropped by 27% with ACD and by 34% with CPD at the maximum decrease of AOP immediately after the AT. The corresponding increase of citrate was 174% with ACD and 521% with CPD, while total calcium remained stable. Thus cardiac depression after AT of citrated blood seems to be mainly caused by the drop of Ca++, which is significantly more pronounced with CPD, corresponding to the higher content of citrate.