Bilirubin and alkaline phosphatase values before and after surgery for biliary obstruction.

From a study of 178 patients who underwent operation for biliary obstruction, we found that preoperative bilirubin values above 14 mg/dl and alkaline phosphatase values over 5 times normal meant that common duct stones were an unlikely cause of the obstruction. Jaundice for more than 4 weeks before operation, bilirubin values greater than 10 mg/dl and the presence of significant fibrosis in the portal spaces indicated a lower than average chance of postoperative resolution of jaundice. After successful biliary surgery, the rate of decrease in serum alkaline phosphatase was haphazard and of little diagnostic value. The postoperative rate of decrease in the bilirubin values followed first-order kinetics and averaged 8 percent/day. This rate was not significantly influenced by the disease process, the length of preoperative clinical jaundice or the absolute height of the preoperative serum bilirubin level.