Postoperative renal dysfunction can be predicted.

The two prior hypotheses of the study were that, among a high risk population of patients who were hypertensive, who had diabetes and who underwent elective general surgical treatment, the duration of intraoperative hypotension and hypertension (greater than 20 millimeters of mercury above or below the preoperative base line) and intraoperative administration of less than 300 milliliters per hour of saline solution containing fluids would identify patients at higher risk for postoperative renal dysfunction. Among those who had an intraoperative mean arterial pressure (MAP) that fell more than 20 millimeters of mercury below the base line, 15 per cent of those with fall of MAP lasting for greater than or equal to 60 minutes had postoperative renal dysfunction, whereas those with drops in pressure lasting for less than 60 minutes did not sustain increased postoperative renal dysfunction. Patients who had intraoperative MAP rise to greater than 20 millimeters of mercury above the preoperative base line value for greater than 30 minutes also had twice the rate of postoperative renal dysfunction. Fifteen per cent of the patients who received less than 300 milliliters per hour of isotonic saline-like fluids had postoperative renal dysfunction, significantly more than the 8 per cent of those who received greater than or equal to 300 milliliters per hour. Two intraoperative events also significantly increased postoperative renal dysfunction rates: cardiac arrest and the drainage of massive ascites. Patients with decompensated congestive heart failure at admission to the hospital had significantly increased postoperative renal dysfunction; these patients and probably should not undergo an operation unless it is an emergency. All of the patients, regardless of the magnitude of the operation and of its projected length or type of anesthesia, should be given greater than 300 milliliters per hour of isotonic saline-like solutions.