Prediction of hypofibrinogenaemia based on the starting fibrinogen and extent of haemodilution during cardiac surgery.

It is now recognised that correction of hypofibrinogenaemia is a priority in the management of coagulopathic bleeding, once drug-related causes have been reversed as far as possible. 1,2 Correction of low fibrinogen levels has also been shown to improve clot strength in the presence of thrombocytopenia. 2,3 For this reason, an additional alert to the likelihood of hypofibrinogenaemia may help clinicians to improve coagulation management, by prompting them to measure the fibrinogen level, and replace fibrinogen in a timely manner if nec-essary. We reasoned that such an alert could be obtained by considering the preoperative fibrinogen level and the extent of haemodilution pertaining at any particular stage of a procedure. This reasoning is based on the fact that fibrinogen is a large molecule, which under normal circumstances is confined to the intravascular space in the same way as haemoglobin. 4,5 Moreover, normal levels are not restored immediately, but instead occur over several hours. 6,7 Therefore, any reduction in the haemoglobin level caused by blood loss and its replacement with non-sanguineous fluid should be accompanied by a similar or greater proportional reduction in the fibrinogen level, assuming no blood products have been administered. We