Intraoperative Fluid Strategy

Perioperative goal-directed haemodynamic therapy (GDHT) includes a variety of protocolised approaches to the assessment and management of the circulatory system and blood flow for patients undergoing surgery. Here we present updated consensus statements on perioperative GDHT developed during the 11th Perioperative Quality Initiative (POQI) consensus conference meeting held in London, UK in June, 2023. Statements relating to the definitions, components, and underlying physiology surrounding GDHT are proposed. We recommend considering use of GDHT in specific settings including during cardiopulmonary bypass (CPB), after cardiac surgery, and during hip fracture surgery. However, the level of evidence is weak in these settings. Clinicians can consider use of GDHT protocols on an individual patient basis for moderate- to high-risk patients undergoing major noncardiac surgery; however, we recommend against use of fixed low-dose inotrope infusions as part of GDHT protocols. We do not recommend routine use of GDHT protocols for patients undergoing major elective abdominal surgery. There is currently insufficient evidence to recommend routine use of GDHT during emergency abdominal surgery. Future research should focus on individualisation of GDHT to individual patients' haemodynamic requirements, newer paradigms such as technology-assisted delivery of GDHT protocols, and the role of predictive models using artificial intelligence.

Fluid therapy during major surgery can be managed by providing repeated bolus infusions until stroke volume no longer increases by&#x2009;&#x2265;&#x2009;10%. However, the final bolus in an optimization round increases stroke volume by&#x2009;<&#x2009;10% and is not necessary. We studied how different cut-off values for the hemodynamic indications given by esophagus Doppler monitoring, as well as augmentation by pulse oximetry, are associated with a higher or smaller chance that stroke volume increases by &#x2265;&#x2009;10% (fluid responsiveness) before fluid is infused. An esophagus Doppler and a pulse oximeter that displayed the pleth variability index were used to monitor the effects of a bolus infusion in 108 patients undergoing goal-directed fluid therapy during major open abdominal surgery. The analyzed data set comprised 266 bolus infusions. The overall incidence of fluid responsiveness was 44%, but this varied greatly depending on pre-infusion hemodynamics. The likelihood of being fluid-responsive was 30%-38% in the presence of stroke volume&#x2009;>&#x2009;80&#x2009;mL, corrected flow time&#x2009;>&#x2009;360&#x2009;ms, or pleth variability index&#x2009;<&#x2009;10%. The likelihood was 21% if stroke volume had decreased by <8% since the previous optimization, which decreased to 0% if combined with stroke volume&#x2009;>&#x2009;100&#x2009;mL. By contrast, the likelihood of fluid responsiveness increased to 50%-55% when stroke volume&#x2009;&#x2264;&#x2009;50&#x2009;mL, corrected flow time&#x2009;&#x2264;&#x2009;360&#x2009;ms, or pleth variability index &#x2265;&#x2009;10. A decrease in stroke volume by&#x2009;>&#x2009;8% since the previous optimization was followed by a 58% likelihood of fluid responsiveness that, in combination with any of the other hemodynamic variables, increased to 66%-76%. Single or combined hemodynamic variables provided by esophagus Doppler monitoring and pulse oximetry derived pleth variability index could help clinicians avoid unnecessary fluid bolus infusions.

Much uncertainty exists as to whether peri-operative goal-directed therapy is of benefit. To discover if peri-operative goal-directed therapy decreases mortality and morbidity in adult surgical patients. An updated systematic review and random effects meta-analysis of randomised controlled trials. Medline, Embase and the Cochrane Library were searched up to 31 December 2016. Randomised controlled trials enrolling adult surgical patients allocated to receive goal-directed therapy or standard care were eligible for inclusion. Trauma patients and parturients were excluded. Goal-directed therapy was defined as fluid and/or vasopressor therapy titrated to haemodynamic goals [e.g. cardiac output (CO)]. Outcomes included mortality, morbidity and hospital length of stay. Risk of bias was assessed using Cochrane methodology. Ninety-five randomised trials (11&#x200a;659 patients) were included. Only four studies were at low risk of bias. Modern goal-directed therapy reduced mortality compared with standard care [odds ratio (OR) 0.66; 95% confidence interval (CI) 0.50 to 0.87; number needed to treat&#x200a;=&#x200a;59; N = 52; I&#x200a;=&#x200a;0.0%]. In subgroup analysis, there was no mortality benefit for fluid-only goal-directed therapy, cardiac surgery patients or nonelective surgery. Contemporary goal-directed therapy also reduced pneumonia (OR 0.69; 95% CI, 0.51 to 0. 92; number needed to treat&#x200a;=&#x200a;38), acute kidney injury (OR 0. 73; 95% CI, 0.58 to 0.92; number needed to treat&#x200a;=&#x200a;29), wound infection (OR 0.48; 95% CI, 0.37 to 0.63; number needed to treat&#x200a;=&#x200a;19) and hospital length of stay (days) (-0.90; 95% CI, -1.32 to -0.48; I&#x200a;=&#x200a;81. 2%). No important differences in outcomes were found for the pulmonary artery catheter studies, after accounting for advances in the standard of care. Peri-operative modern goal-directed therapy reduces morbidity and mortality. Importantly, the quality of evidence was low to very low (e.g. Grading of Recommendations, Assessment, Development and Evaluation scoring), and there was much clinical heterogeneity among the goal-directed therapy devices and protocols. Additional well designed and adequately powered trials on peri-operative goal-directed therapy are necessary.

Transthoracic oesophagectomy is associated with major morbidity and mortality, which may be reduced by goal-directed therapy (GDT). The aim of this multicentre, RCT was to evaluate the impact of intraoperative GDT on major morbidity and mortality in patients undergoing transthoracic oesophagectomy. Adult patients undergoing transthoracic oesophagectomy were randomised to receive either minimally invasive intraoperative GDT (stroke volume variation <8%, plus systolic BP maintained >90 mm Hg by pressors as necessary) or haemodynamic management left to the discretion of attending senior anaesthetists (control group; systolic BP >90 mm Hg alone). The primary outcome was the incidence of death or major complications (reoperation for bleeding, anastomotic leakage, pneumonia, reintubation, >48 h ventilation). A Cox proportional hazard model was used to examine whether the effects of GDT on morbidity and mortality were independent of other potential confounders. A total of 232 patients (80.6% male; age range: 36-83 yr) were randomised to either GDT (n=115) or to the control group (n=117). After surgery, major morbidity and mortality were less frequent in 22/115 (19.1%) subjects randomised to GDT, compared with 41/117 (35.0%) subjects assigned to the control group {absolute risk reduction: 15.9% (95% confidence interval [CI]: 4.7-27.2%); P=0.006}. GDT was also associated with fewer episodes of atrial fibrillation (odds ratio [OR]: 0.18 [95% CI: 0.05-0.65]), respiratory failure (OR: 0.27 [95% CI: 0.09-0.83]), use of mini-tracheotomy (OR: 0.29 [95% CI: 0.10-0.81]), and readmission to ICU (OR: 0.09 [95% CI: 0.01-0.67]). GDT was independently associated with morbidity and mortality (hazard ratio: 0.51 [95% CI: 0.30-0.87]; P=0.013). Intraoperative GDT may reduce major morbidity and mortality, and shorten hospital stay, after transthoracic oesophagectomy. UMIN000018705.

Perioperative fluid management impacts outcomes and plays a pivotal role in enhanced recovery pathways (ERPs). There have been major advances in understanding the effects of fluid therapy and administration during the perioperative period. Improving fluid management during this period leads to a decrease in complications, decrease in length of stay (LOS), and enhanced patient outcomes. It is important to consider preoperative and postoperative fluid management to be just as critical as intraoperative management given multiple associated benefits to the patients. Preoperative hydration with (complex) carbohydrate drinks up until 2&#xa0;h before surgery is safe and should be encouraged, as this helps improve metabolism, decrease insulin resistance, reduce anxiety, and reduce nausea and vomiting. During the intraoperative period, the goals of fluid management are to maintain euvolemia using an individualized plan for fluid and haemodynamic management, matching the needs for monitoring with patient and surgical risk through goal-directed therapy (GDT). By combining the use of fluids and inotropes, GDT uses measurements and indicators of cardiac output and stroke volume to improve blood flow intraoperatively, and ultimately reduce LOS and complications. In the postoperative period, an early transition to oral hydration helps to enhance the conditions for healing and recovery from surgery. I.V. fluid therapy should be kept at a minimum, and urine output should not be the driving force for fluid administration. The optimization of perioperative fluid management is critical to ERPs as it helps improve pulmonary function, tissue oxygenation, gastrointestinal motility, and wound healing.

Appropriate perioperative fluid management is of pivotal importance to reduce postoperative complications, which impact on early and long-term patient outcome. The so-called perioperative goal-directed therapy (GDT) approach aims at customizing perioperative fluid management on the individual patients' hemodynamic response. Whether or not the overall amount of perioperative volume infused in the context of GDT could influence postoperative surgical outcomes is unclear. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) comparing the efficacy of GDT approach between study population and control group in reducing postoperative complications and perioperative mortality, using MEDLINE, EMBASE and the Cochrane Controlled Clinical trials register. The enrolled studies were grouped considering the amount infused intraoperatively and during the first 24&#xa0;h after the admission in the critical care unit (perioperative fluid). The metanalysis included 21 RCTs enrolling 2729 patients with a median amount of perioperative fluid infusion of 4500&#xa0;ml. In the studies reporting an overall amount below or above this threshold, the differences in postoperative complications were not statically significant between controls and GDT subgroup [43.4% vs. 34.2%, p value&#x2009;=&#x2009;0.23 and 54.8% vs. 39.8%; p value&#x2009;=&#x2009;0.09, respectively]. Overall, GDT reduced the overall rate of postoperative complications, as compared to controls [pooled risk difference (95% CI)&#x2009;=&#x2009;-&#x2009;0.10 (-&#x2009;0.14, -&#x2009;0.07); Chi2&#x2009;=&#x2009;30.97; p value&#x2009;<&#x2009;0.0001], but not to a reduction of perioperative mortality [pooled risk difference (95%CI)&#x2009;=&#x2009;-&#x2009;0.016 (-&#x2009;0.0334; 0.0014); p value&#x2009;=&#x2009;0.07]. Considering the rate of organ-related postoperative events, GDT did not reduce neither renal (p value&#x2009;=&#x2009;0.52) nor cardiovascular (p value&#x2009;=&#x2009;0.86) or pulmonary (p value&#x2009;=&#x2009;0.14) or neurological (p value&#x2009;=&#x2009;0.44) or infective (p value&#x2009;=&#x2009;0.12) complications. Irrespectively to the amount of perioperative fluid administered, GDT strategy reduces postoperative complications, but not perioperative mortality. CRD42020168866; Registration: February 2020 https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=168866.