Is postoperative oliguria avoidable?

Postoperative salt and water retention has been recognized for most of this century. Does it matter? Can or should it be avoided? These are still questions about which debate continues. Pringle, in 1905, observed reduced urine volumes and weight gain in postoperative patients [31]. Wilkinson studied 27 patients perioperatively and observed a decrease in urinary concentrations of sodium and chloride despite i.v. and oral fluids, and concluded that sodium retention was not the result of reduced intake, but was an unavoidable response to surgery [43]. Moyer recorded a marked reduction in the urinary excretion of water, chloride, sodium and urea [28]. He recommended avoidance of the use of glucose solutions while the period of reduced water excretion lasted, giving saline only if signs of deficit occurred or there was evidence of abnormal extra losses. In 1953, Le Quesne showed that sodium and water retention occurred postoperatively whether or not sodium supplements were given. A weight gain of about 2 kg was seen in his patients, even in those given no sodium supplements. These patients were unable to produce a hypotonic urine [21]. Early attempts were made to accommodate this salt and water retention by curtailing fluid intake and by 1952 the view had arisen, particularly in Europe, that fluid restriction in the perioperative period was important [24].