50-50 Criteria of Balzan et al for Liver Failure After Hepatectomy

Elements of 50-50 rule:

(1) postoperative day 5 (with day of surgery day 0)

(2) “prothrombin time” < 50% of normal, which corresponds to an INR > 1.7

(3) serum total bilirubin > 50 µmol/L

The change in “prothrombin time” refers to the coagulopathy of liver disease, with a decrease in coagulation factors, especially Factor VII. The prothrombin time increases with the coagulopathy, so the reference should be to prothrombin index, which is more often measured in Europe.

There should be no other factors affecting the INR. The authors did not transfuse fresh frozen plasma (FFP) or provide other coagulation factor replacement during the first week after surgery.

Balzan found the the 50-50 criteria had an odds ratio of 216 for postoperative mortality after liver resection.