This Month in Anesthesiology

To address debates over recommended perioperative fluid management, Nisanevich et al. designed a randomized prospective study to compare liberal versus restricted fluid administration during intraabdominal surgery. The team enrolled 152 patients scheduled to undergo intraabdominal surgery, and randomly assigned half of them (n 75) to receive liberal amounts of lactated Ringer’s solution (bolus of 10 ml/kg followed by 12 ml · kg 1 · hr ) during surgery. A total of 77 were patients assigned to the restrictive fluids group, consisting of 4 ml · kg 1 · hr . Besides the primary endpoint of death or development of complications, the investigators’ secondary outcomes for the study included time to initial passage of flatus and feces, length of hospital stay, changes in body weight, and hematocrit and albumin serum concentration during the first three postoperative days. Procedures included in the study ranged from small bowel resections, to partial pancreas resections to gastric resections. All patients received identical bowel preparations prior to surgery and were fasted after midnight. Standard anesthesia management included induction with thiopental, fentanyl, and vecuronium and maintenance with isoflurane, nitrous oxide, and oxygen. Epidural administration of bupivacaine and methadone were given for postoperative pain until postoperative day three. Study fluid regimens were continued until admission to the recovery room, and surgery and postsurgery personnel were blinded as to study group assignment. Investigators established transfusion guidelines for administration of fresh frozen plasma, cryoprecipitate, and platelets if bleeding became uncontrolled. Blood loss, urine output, and doses of drugs given during the surgical procedure were recorded. None of the patients in the study died during the perioperative period. Those in the restricted fluids group had fewer complications than those in the liberal fluids group, although there were 20 in the restricted fluids group who suffered episodes of hypotension. Patients in the liberal fluids group passed flatus and feces an average of 1 day later than those in the restricted fluids group, and their hospital stays were longer. Hematocrit and albumin concentrations, however, were higher in the restricted fluids group during the first 3 postoperative days. Although additional studies are needed to establish optimum volumes of fluid to be infused during and after intraabdominal surgery, these findings do suggest that intraoperative use of restrictive fluid management might be advantageous for reducing postoperative morbidity and shortening hospital stays.