Preoperative evaluation of hepatic reserve function by phenacetin metabolism test for the prevention of postoperative liver dysfunction

The aim of this study was to investigate the utility of the phenacetin metabolism test in evaluating hepatic reserve function prior to hepatectomy for the prevention of postoperative liver dysfunction. Fifty-six patients with hepatocellular carcinoma had undergone hepatectomy. Patients were classified into group I (normal group, n = 37) and group II (with peak total bilirubin >53.8 μmol/L for 7 days after hepatectomy, n = 19) based on the levels of total bilirubin after hepatectomy. The receiver operating characteristic (ROC) analysis was made to assess the hepatic reserve function to predict liver dysfunction of the patients after hepatectomy. Hepatic reserve function was evaluated by phenacetin metabolism test; the ratio of plasma total paracetamol to phenacetin at 2 h after oral 1.0 g phenacetin. There were no significant differences in preoperative variables or intraoperative findings except the ratio of plasma total paracetamol to phenacetin. ROC analysis showed that the sensitivity and specificity of the ratio of plasma total paracetamol to phenacetin ≤1.2 were 85.4 and 72.9%, respectively for predicting liver dysfunction of the patients after hepatectomy. The ratio of plasma total paracetamol to phenacetin correlated with the temporary postoperative liver dysfunction (P = 0.008). Phenacetin metabolism test before hepatectomy appears to provide direct and reliable measure of hepatic reserve function, thus helping in surgical decision making regarding the extent of hepatectomy and in the prevention of the occurrence of postoperative liver dysfunction.