Intraoperative restrictive versus liberal fluid administration and postoperative outcomes in major abdominal elective surgery: A retrospective study

Background: Despite extensive research on perioperative fluid management, there remains a lack of consensus on the optimal approach. While some evidence suggests that a restrictive approach during the perioperative period may decrease the incidence of postoperative complications, other recent studies have demonstrated an association between a restrictive fluid regimen and acute kidney injury due to hypoperfusion. Most studies were done for colorectal surgery and the results extrapolated for pancreatic and hepatic surgery. However, these are complex procedures with unique surgical and anesthestic challenges and therefore deserve special attention. Objectives: The present study compares the impact of a restrictive versus liberal intraoperative fluid administration on early postoperative outcomes after pancreatic or hepatic surgery. Methods: We performed a retrospective analysis to all patients who underwent pancreatic or liver surgery in a single centre between august 2017 and august 2022. Exclusion criteria were intraoperative surgical complications, preoperatively dialysed patients, non-elective surgery and patients who were not admitted to the intensive care unit in the postoperative period. A cut-off value of 2000mL was applied based on an exhaustive literature review and the patients were categorized in two groups according to the volume of intraoperative fluid administered: restrictive (<2000mL, n=83) and liberal (=2000mL, n=34). The postoperative outcomes included major postoperative complications, acute kidney injury, electrolyte disturbances, postoperative vasopressor administered and peak serum lactate levels. Results: We evaluated 117 patients. There were no statistically significant differences in age, sex, body mass index, type of surgery and ASA physical status between the two groups. Patients in the liberal group received significantly more intraoperative fluid (P=0.001). Both groups had comparable intraoperative vasopressor administration. The liberal group showed a higher incidence of electrolytic disturbances (P=0,046). The median peak lactate level was significantly higher in the liberal group (P=0,026) compared to the restrictive group. The other outcomes such as postoperative vasopressor administration, acute kidney injury, anastomotic dehiscence and pulmonary oedema were similar among the groups. Conclusion: In patients undergoing pancreatic or liver surgery, a liberal intraoperative fluid administration was associated with higher peak serum lactate level and increased incidence of electrolyte disturbances up to 48 hours after the procedure compared to a restrictive intraoperative fluid administration.Introdução: Apesar da vasta investigação sobre a gestão da fluidoterapia perioperatória, a falta de consenso sobre a abordagem ideal continua a prevalecer. Embora alguns estudos sugiram que uma abordagem restritiva dos fluidos durante o período peri-operatório pode diminuir a incidência de complicações pós-operatórias, outros demonstram haver uma correlação entre o regime restritivo e o diagnóstico de lesão renal aguda, secundário à hipoperfusão de órgão. A maior parte dos estudos realizados neste âmbito são dirigidos a cirurgia colorretal e os resultados posteriormente extrapolados para a cirurgia pancreática e hepática, que sendo complexas, acarretam desafios cirúrgicos e anestésicos únicos que merecem especial atenção. Objetivos: O objetivo deste estudo foi comparar o impacto que as abordagens restritiva e liberal de fluidoterapia intra-operatória têm sobre os resultados pós-operatórios em cirurgias eletivas do pâncreas e fígado. Métodos: Foram avaliados todos os doentes submetidos a cirurgia eletiva pancreática ou hepática entre Agosto de 2017 e Agosto de 2022, num único hospital. Doentes submetidos a cirurgias que registaram complicações cirúrgicas intraoperatórias, doentes submetidos a hemodiálise, cirurgias não eletivas e casos que não requereram internamento na Unidade de Cuidados Intensivos, foram excluídos deste estudo. Foi definido um valor cut-off de 2000mL baseado na revisão bibliográfica realizada. Os doentes foram divididos e categorizados em dois grupos distintos, tendo em conta a quantidade de fluido administrada no período intra-operatório: restritivo (