Renal impairment following biliary tract surgery
Postoperative mortality has been directly attributed to renal failure in approximately 5 per cent of patients after surgery for obstructive jaundice. An analysis of 334 patients undergoing biliary tract surgery was undertaken to identify the perioperative factors associated with the development of renal impairment, and to estimate the contribution of renal failure to mortality. Thirty-eight patients (11 per cent) developed postoperative renal impairment (a two-fold increase in serum creatinine postoperatively or a rise of greater than 100 mumol/l). Ninety-three factors were examined in these and 196 control patients. Stepwise logistic regression analysis identified only three factors which were significantly associated with renal impairment: postoperative sepsis (P less than 0.0005), pre-operative serum bilirubin (P less than 0.0005), and pre-operative urea (P less than 0.05). Renal impairment developed at a median 4 days after surgery and was associated with a median of two additional major postoperative complications, particularly sepsis and haemorrhage, for which 17 patients underwent reoperation. Twenty-eight (74 per cent) of the patients with renal impairment died in hospital, but in only one case was the cause of death directly related to renal failure. Twenty patients received specific therapy for renal failure, but only one of these survived. Pre-operative obstructive jaundice and postoperative infection are the major factors associated with renal impairment after biliary tract surgery. Renal impairment appears to be related to postoperative complications rather than directly to the surgical procedure itself. The development of postoperative renal impairment predicts a low chance of survival but appears to be an indicator, rather than a direct cause of a poor prognosis.