Restrictive versus liberal fluid therapy in geriatric patients undergoing major abdominal surgery: a randomized controlled trial

BACKGROUND: The optimal fluid therapy in elderly patients undergoing major abdominal surgery remains unclear. Although some trials have reported a restrictive fluid therapy may lead to better outcomes, there is no evidence whether it is suitable for elderly patients. METHODS: In a double-blinded pragmatic trial, 107 elderly patients undergoing major abdominal surgery were randomized to receive either a liberal (L group) or restrictive intravenous-fluid therapy (R group) . The postoperative fluid therapy was similar in the two groups. The primary outcome was vital organ injury included Myocardial injury after noncardiac surgery (MINS) and acute kidney injury（AKI）, the secondary outcomes included hypotension needed intervention intraoperatively, length of stay (LOS) , death and other complications defined up to 30 days. Analysis was performed by intention-to-treat. RESULT: 50 patients in the L group had an average intravenous fluid of 1943ml, as compared to 1295.61ml in 57 patients in the R group (P<0.001). The baseline Characteristics and operative details were similar between the groups. Patients in the L group had a lower rate of AKI (10% vs 35.1%, P=0.002) and surgical-site infection (0 vs 10.5%, P=0.029) than in the R group；MINS (20% vs 20.8%, P=0.724) and the other postoperative complications showed no differences between two groups. One patient died in the R group. No significant difference was found for the length of hospital stay[median(range) L: 15(8-49) vs R: 17(8-80); P=0.27]. The follow-up was 30 days. CONCLUSION: In geriatric patients undergoing major abdominal surgery, a liberal fluid regimen was associated with a lower rate of AKI and postoperative infection than restrictive fluid regimen and did not increase the risk of postoperative complications. Trial registration: ChiCTR1800019022. Registered 21 October 2018