[A discussion of standardization for prothrombin time in patients with advanced liver diseases]

To determine which expression mode of prothrombin time (PT) might achieve PT standardization in patients with advanced liver diseases.

PT was measured with six thromboplastins with different ISI values in 16 severe chronic hepatitis patients, 50 decompensated liver cirrhosis patients and 30 patients on oral anticoagulation therapy. The results were expressed in PT (second), PTA (%), PTR and INR.

In chronic hepatitis patients, the means of the six group's PTAs ranged from 24% to 34%, while their upper limits ranged from 47% to 61%. The means of the INRs ranged from 2.55 to 5.13, while their upper limits ranged from 4.65 to 12.77. Through one-way ANOVA of repeated measures, PPTA (0.489) was > PINR (0.120). In patients with liver cirrhosis, the means of the PTA in six groups ranged from 50% to 59%, while their upper limits ranged from 82% to 90%. The means of the INR ranged from 1.40 to 1.80, while their upper limits ranged from 1.97 to 3.69. Through one-way ANOVA of repeated measures, PPTA (0.102) was > PINR (0.01). In patients on oral coagulation therapy, the means of PTA ranged from 26% to 37%, while their upper limits ranged from 39% to 49%. The means of INR ranged from 2.35 to 2.66, while their upper limits ranged from 3.16 to 4.26. Through one-way ANOVA of repeated measures, PPTA (0.01) was less than PINR (0.102). The correlation between the results detected by Neoplastine and by other reagents were analyzed. They correlated well with each other when PTA was used as the expression mode of PT in patients with advanced liver disease. But in patients on oral anticoagulation therapy, when only the INR was used as the expression mode of PT, the correlation was well with each other.

The use of INR provides inadequate standardization. Only when the PT is expressed in PTA, then it may provide a standardization mode in patients with advanced liver diseases.