Personalized Versus Protocolized Fluid Management Using Noninvasive Hemodynamic Monitoring (Clearsight System) in Patients Undergoing Moderate-Risk Abdominal Surgery

Perioperative Fluid and Vasopressor Therapy in 2050: From Experimental Medicine to Personalization Through Automation

Intravenous (IV) fluids and vasopressor agents are key components of hemodynamic management. Since their introduction, their use in the perioperative setting has continued to evolve, and we are now on the brink of automated administration. IV fluid therapy was first described in Scotland during the 1832 cholera epidemic, when pioneers in medicine saved critically ill patients dying from hypovolemic shock. However, widespread use of IV fluids only began in the 20th century. Epinephrine was discovered and purified in the United States at the end of the 19th century, but its short half-life limited its implementation into patient care. Advances in venous access, including the introduction of the central venous catheter, and the ability to administer continuous infusions of fluids and vasopressors rather than just boluses, facilitated the use of fluids and adrenergic agents. With the advent of advanced hemodynamic monitoring, most notably the pulmonary artery catheter, the role of fluids and vasopressors in the maintenance of tissue oxygenation through adequate cardiac output and perfusion pressure became more clearly established, and hemodynamic goals could be established to better titrate fluid and vasopressor therapy. Less invasive hemodynamic monitoring techniques, using echography, pulse contour analysis, and heart-lung interactions, have facilitated hemodynamic monitoring at the bedside. Most recently, advances have been made in closed-loop fluid and vasopressor therapy, which apply computer assistance to interpret hemodynamic variables and therapy. Development and increased use of artificial intelligence will likely represent a major step toward fully automated hemodynamic management in the perioperative environment in the near future. In this narrative review, we discuss the key events in experimental medicine that have led to the current status of fluid and vasopressor therapies and describe the potential benefits that future automation has to offer.

Restricted Versus Liberal Versus Goal-Directed Fluid Therapy for Non-vascular Abdominal Surgery: A Network Meta-Analysis and Systematic Review

Optimal perioperative fluid management is crucial, with over- or under-replacement associated with complications. There are many strategies for fluid therapy, including liberal fluid therapy (LFT), restrictive fluid therapy (RFT) and goal-directed fluid therapy (GDT), without a clear consensus as to which is better. We aimed to find out which is the more effective fluid therapy option in adult surgical patients undergoing non-vascular abdominal surgery in the perioperative period. This study is a systematic review and network meta-analysis (NMA) with node-splitting analysis of inconsistency, sensitivity analysis and meta-regression. We conducted a literature search of Pubmed, Cochrane Library, EMBASE, Google Scholar and Web of Science. Only studies comparing restrictive, liberal and goal-directed fluid therapy during the perioperative phase in major non-cardiac surgery in adult patients will be included. Trials on paediatric patients, obstetric patients and cardiac surgery were excluded. Trials that focused on goal-directed therapy monitoring with pulmonary artery catheters and venous oxygen saturation (SvO2), as well as those examining purely biochemical and laboratory end points, were excluded. A total of 102 randomised controlled trials (RCTs) and 78 studies (12,100 patients) were included. NMA concluded that goal-directed fluid therapy utilising FloTrac was the most effective intervention in reducing the length of stay (LOS) (surface under cumulative ranking curve (SUCRA) = 91%, odds ratio (OR) = -2.4, 95% credible intervals (CrI) = -3.9 to -0.85) and wound complications (SUCRA = 86%, OR = 0.41, 95% CrI = 0.24 to 0.69). Goal-directed fluid therapy utilising pulse pressure variation was the most effective in reducing the complication rate (SUCRA = 80%, OR = 0.25, 95% CrI = 0.047 to 1.2), renal complications (SUCRA = 93%, OR = 0.23, 95% CrI = 0.045 to 1.0), respiratory complications (SUCRA = 74%, OR = 0.42, 95% CrI = 0.053 to 3.6) and cardiac complications (SUCRA = 97%, OR = 0.067, 95% CrI = 0.0058 to 0.57). Liberal fluid therapy was the most effective in reducing the mortality rate (SUCRA = 81%, OR = 0.40, 95% CrI = 0.12 to 1.5). Goal-directed therapy utilising oesophageal Doppler was the most effective in reducing anastomotic leak (SUCRA = 79%, OR = 0.45, 95% CrI = 0.12 to 1.5). There was no publication bias, but moderate to substantial heterogeneity was found in all networks. In preventing different complications, except mortality, goal-directed fluid therapy was consistently more highly ranked and effective than standard (SFT), liberal or restricted fluid therapy. The evidence grade was low quality to very low quality for all the results, except those for wound complications and anastomotic leak.

Effects of Goal-Directed Hemodynamic Therapy Using a Noninvasive Finger-Cuff Monitoring Device on Intraoperative Cerebral Oxygenation and Early Delayed Neurocognitive Recovery in Patients Undergoing Beach Chair Position Shoulder Surgery: A Randomized Controlled Trial

BACKGROUND

Perioperative cerebral desaturation events (CDEs) and delayed neurocognitive recovery are common among patients undergoing beach chair position (BCP) shoulder surgery and may be caused by cerebral hypoperfusion. This study tested the hypothesis that the application of goal-directed hemodynamic therapy (GDHT) would attenuate these conditions.

METHODS

We randomly assigned 70 adult patients undergoing BCP shoulder surgery to GDHT group or control at a 1:1 ratio. Cerebral oxygenation was monitored using near-infrared spectroscopy, and GDHT was administered using the ClearSight pulse wave analysis system. The primary outcome was CDE duration, whereas the secondary outcomes were CDE occurrence, delayed neurocognitive recovery occurrence, and Taiwanese version of the Quick Mild Cognitive Impairment (Qmci-TW) test score on the first postoperative day (T 2 ) adjusted for the baseline score (on the day before surgery; T 1 ).

RESULTS

CDE duration was significantly shorter in the GDHT group (0 [0-0] vs 15 [0-75] min; median difference [95% confidence interval], -8 [-15 to 0] min; P = .007). Compared with the control group, fewer patients in the GDHT group experienced CDEs (23% vs 51%; relative risk [95% confidence interval], 0.44 [0.22-0.89]; P = .025) and mild delayed neurocognitive recovery (17% vs 40%; relative risk [95% confidence interval], 0.60 [0.39-0.93]; P = .034). The Qmci-TW scores at T 2 adjusted for the baseline scores at T 1 were significantly higher in the GDHT group (difference in means: 4 [0-8]; P = .033).

CONCLUSIONS

Implementing GDHT using a noninvasive finger-cuff monitoring device stabilizes intraoperative cerebral oxygenation and is associated with improved early postoperative cognitive scores in patients undergoing BCP shoulder surgery.

Arterial Lactate Concentration at the End of Liver Transplantation is Independently Associated With One-Year Mortality

BACKGROUND

Liver transplant patients who develop hyperlactatemia are at increased risk of postoperative morbidity and short-term mortality, but there are few data on longer-term outcomes. We therefore investigated if arterial lactate concentration obtained immediately after surgery, at the time of admission to the intensive care unit (ICU), was associated with 1-year mortality.

METHODS

In this retrospective cohort study, all patients who underwent liver transplant surgery from a deceased donor between September 2013 and December 2019 were screened for inclusion. Patients who underwent combined transplantation surgery and those with a history of previous liver transplantation (ie, redo surgery) were not included. Logistic regression modeling included univariate and multivariate analyses. Receiver operating characteristic curves and areas under the curves were calculated. Lactate thresholds and association with outcome were analyzed for specificity, sensitivity, and Youden's index.

RESULTS

Of 226 patients included, 18.4% died within 1 year of liver transplantation. Immediate postoperative lactate concentration was independently associated with 1-year mortality with an adjusted odds ratio of 1.35 (95% CI 1.16-1.59; P < .001) per mmol/L increase in lactate and an area under the curve of 0.80 (95% CI 0.72-0.87; P < .001). A lactate concentration of 2.25 mmol/L (cutoff determined using Youden's index) was associated with increased 1-year mortality with a sensitivity of 0.71 and a specificity of 0.72.

CONCLUSIONS

Increased arterial lactate concentration on admission to the intensive care unit immediately after orthotopic liver transplantation is independently associated with increased 1-year mortality.

A Pilot Study Assessing a Closed-Loop System for Goal-Directed Fluid Therapy in Abdominal Surgery Patients

Background: This prospective multicentre pilot study of patients scheduled for elective major abdominal surgery aimed to validate the fluid challenge (FC) proposed by the closed-loop (CL) system via anaesthesiologist assessment. Methods: This was a phase II trial consisting of two inclusion stages (SIMON method). Each FC (250 mL saline solution for 10 min) proposed by the CL was systematically validated by the anaesthesiologist who could either confirm or refuse the FC or give FC without the CL system. A ≥ 95% agreement between the CL and the anaesthesiologist was considered acceptable. Results: The study was interrupted after interim analysis of the first 19 patients (10 men, median age = 61 years, median body mass index = 26 kg/m2). The anaesthesiologists accepted 165/205 (80%) of fluid boluses proposed by the CL. Median cardiac index (CI) was 2.9 (interquartile: IQ (2.7; 3.4) L/min/m2) and the median coefficient of variation (CV) for CI was 13% (10; 17). Fifteen out of nineteen patients (79%) had a mean CI > 2.5 L/min/m2 or spent > 85% surgery time with pulse pressure variation < 13%. No adverse events related to the CL were reported. Conclusion: In this study of patients scheduled for elective major abdominal surgery, the agreement between CL and anaesthesiologist for giving fluid challenge was 80%, suggesting that CL cannot replace the physician but could help in decision making.

Goal-Directed Fluid Therapy Enhances Gastrointestinal Recovery after Laparoscopic Surgery: A Systematic Review and Meta-Analysis

(1) Background: Whether goal-directed fluid therapy (GDFT) provides any outcome benefit as compared to non-goal-directed fluid therapy (N-GDFT) in elective abdominal laparoscopic surgery has not been determined yet. (2) Methods: A systematic literature search was conducted in MEDLINE, Embase, CENTRAL, Web of Science, and Scopus. The main outcomes were length of hospital stay (LOHS), time to first flatus and stool, intraoperative fluid and vasopressor requirements, serum lactate levels, and urinary output. Pooled risks ratios (RRs) with 95% confidence intervals (CI) were calculated for dichotomous outcomes and weighted mean difference (WMD) with 95% CI for continuous outcomes. (3) Results: Eleven studies were included in the quantitative, and fifteen in the qualitative synthesis. LOHS (WMD: -1.18 days, 95% CI: -1.84 to -0.53) and time to first stool (WMD: -9.8 h; CI -12.7 to -7.0) were significantly shorter in the GDFT group. GDFT resulted in significantly less intraoperative fluid administration (WMD: -441 mL, 95% CI: -790 to -92) and lower lactate levels at the end of the operation: WMD: -0.25 mmol L-1; 95% CI: -0.36 to -0.14. (4) Conclusions: GDFT resulted in enhanced recovery of the gastrointestinal function and shorter LOHS as compared to N-GDFT.

Impact of conventional vs. goal-directed fluid therapy on urethral tissue perfusion in patients undergoing liver surgery: A pilot randomised controlled trial

BACKGROUND

Although fluid administration is a key strategy to optimise haemodynamic status and tissue perfusion, optimal fluid administration during liver surgery remains controversial.

OBJECTIVE

To test the hypothesis that a goal-directed fluid therapy (GDFT) strategy, when compared with a conventional fluid strategy, would better optimise systemic blood flow and lead to improved urethral tissue perfusion (a new variable to assess peripheral blood flow), without increasing blood loss.

DESIGN

Single-centre prospective randomised controlled superiority study.

SETTING

Erasme Hospital.

PATIENTS

Patients undergoing liver surgery.

INTERVENTION

Forty patients were randomised into two groups: all received a basal crystalloid infusion (maximum 2 ml kg-1 h-1). In the conventional fluid group, the goal was to maintain central venous pressure (CVP) as low as possible during the dissection phase by giving minimal additional fluid, while in the posttransection phase, anaesthetists were free to compensate for any presumed fluid deficit. In the GDFT group, patients received in addition to the basal infusion, multiple minifluid challenges of crystalloid to maintain stroke volume (SV) variation less than 13%. Noradrenaline infusion was titrated to keep mean arterial pressure more than 65 mmHg in all patients.

MAIN OUTCOME MEASURE

The mean intra-operative urethral perfusion index.

RESULTS

The mean urethral perfusion index was significantly higher in the GDFT group than in the conventional fluid group (8.70 [5.72 to 13.10] vs. 6.05 [4.95 to 8.75], P = 0.046). SV index (ml m-2) and cardiac index (l min-1 m-2) were higher in the GDFT group (48 ± 9 vs. 33 ± 7 and 3.5 ± 0.7 vs. 2.4 ± 0.4, respectively; P < 0.001). Although CVP was higher in the GDFT group (9.3 ± 2.5 vs. 6.5 ± 2.9 mmHg; P = 0.003), intra-operative blood loss was not significantly different in the two groups.

CONCLUSION

In patients undergoing liver surgery, a GDFT strategy resulted in a higher mean urethral perfusion index than did a conventional fluid strategy and did not increase blood loss despite higher CVP.

TRIAL REGISTRATION

NCT04092608.

Perioperative goal-directed therapy and postoperative complications in different kind of surgical procedures: an updated meta-analysis

BACKGROUND

Goal-directed therapy (GDT) aims to assure tissue perfusion, by optimizing doses and timing of fluids, inotropes, and vasopressors, through monitoring of cardiac output and other basic hemodynamic parameters. Several meta-analyses confirm that GDT can reduce postoperative complications. However, all recent evidences focused on high-risk patients and on major abdominal surgery.

OBJECTIVES

The aim of the present meta-analysis is to investigate the effect of GDT on postoperative complications (defined as number of patients with a least one postoperative complication) in different kind of surgical procedures.

DATA SOURCES

Randomized controlled trials (RCTs) on perioperative GDT in adult surgical patients were included. The primary outcome measure was complications, defined as number of patients with at least one postoperative complication. A subgroup-analysis was performed considering the kind of surgery: major abdominal (including also major vascular), only vascular, only orthopedic surgery. and so on.

STUDY APPRAISAL AND SYNTHESIS METHODS

Meta-analytic techniques (analysis software RevMan, version 5.3.5, Cochrane Collaboration, Oxford, England, UK) were used to combine studies using odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

In 52 RCTs, 6325 patients were enrolled. Of these, 3162 were randomized to perioperative GDT and 3153 were randomized to control. In the overall population, 2836 patients developed at least one complication: 1278 (40%) were randomized to perioperative GDT, and 1558 (49%) were randomized to control. Pooled OR was 0.60 and 95% CI was 0.49-0.72. The sensitivity analysis confirmed the main result. The analysis enrolling major abdominal patients showed a significant result (OR 0.72, 95% CI 0.59-0.87, p = 0.0007, 31 RCTs, 4203 patients), both in high- and low-risk patients. A significant effect was observed in those RCTs enrolling exclusively orthopedic procedures (OR 0.53, 95% CI 0.35-0.80, p = 0.002, 7 RCTs, 650 patients. Also neurosurgical procedures seemed to benefit from GDT (OR 0.40, 95% CI 0.21-0.78, p = 0.008, 2 RCTs, 208 patients). In both major abdominal and orthopedic surgery, a strategy adopting fluids and inotropes yielded significant results. The total volume of fluid was not significantly different between the GDT and the control group.

CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS

The present meta-analysis, within the limits of the existing data, the clinical and statistical heterogeneity, suggests that GDT can reduce postoperative complication rate. Moreover, the beneficial effect of GDT on postoperative morbidity is significant on major abdominal, orthopedic and neurosurgical procedures. Several well-designed RCTs are needed to further explore the effect of GDT in different kind of surgeries.

Hydroxyethyl Starch for Fluid Management in Patients Undergoing Major Abdominal Surgery: A Systematic Review With Meta-analysis and Trial Sequential Analysis

BACKGROUND

In critically ill patients, warnings about a risk of death and acute kidney injury (AKI) with hydroxyethyl starch (HES) solutions have been raised. However, HES solutions may yet have a role to play in major abdominal surgery. This meta-analysis and trial sequential analysis (TSA) aimed to investigate the effect of HES intravascular volume replacement on the risk of AKI, intraoperative blood transfusion, and postoperative intra-abdominal complications compared to crystalloid intravascular volume replacement.

METHODS

In this meta-analysis and TSA, we searched for randomized controlled trials (RCTs) comparing intraoperative HES intravascular volume replacement to crystalloid intravascular volume replacement in adult patients undergoing major abdominal surgery. Primary outcome was 30-day AKI, defined as a binary outcome according to Kidney Disease Improving Global Outcomes (KDIGO) criteria, combining stages 1, 2, and 3 into an AKI category versus no AKI category (stage 0). Secondary outcomes included rates of intraoperative blood transfusion and postoperative intra-abdominal complications. We used random effects models to calculate summary estimates. We used relative risk (RR) as summary measure for dichotomous outcomes, with corresponding 95% confidence intervals (CIs) for the primary outcome (P value <.05 was considered statistically significant) and 99% CI after Bonferroni correction for the secondary outcomes (P value <.01 was considered statistically significant).

RESULTS

Seven RCTs including 2398 patients were included. HES intravascular volume replacement was not associated with an increased risk of 30-day AKI (RR = 1.22, 95% CI, 0.94-1.59; P = .13), when compared to crystalloid intravascular volume replacement. According to TSA, this analysis was underpowered. HES intravascular volume replacement was associated with higher rates of blood transfusion (RR = 1.57 99% CI, 1.10-2.25; P = .001), and similar rates of postoperative intra-abdominal complications (RR = 0.76 99% CI, 0.57-1.02; P = .02).

CONCLUSIONS

In this meta-analysis to focus on HES intravascular volume replacement in major abdominal surgery, HES intravascular volume replacement was not associated with a higher risk of 30-day AKI when compared to crystalloid intravascular volume replacement. However, CI and TSA do not exclude harmful effects of HES intravascular volume replacement on the renal function.

Noninvasive Beat-To-Beat Stroke Volume Measurements to Determine Preload Responsiveness During Mini-Fluid Challenge in a Swine Model: A Preliminary Study

ABSTRACT

Cardiac output (CO) is an important parameter in fluid management decisions for treating hemodynamically unstable patients in intensive care unit. The gold standard for CO measurements is the thermodilution method, which is an invasive procedure with intermittent results. Recently, electrical impedance tomography (EIT) has emerged as a new method for noninvasive measurements of stroke volume (SV). The objectives of this paper are to compare EIT with an invasive pulse contour analysis (PCA) method in measuring SV during mini-fluid challenge in animals and determine preload responsiveness with EIT. Five pigs were anesthetized and mechanically ventilated. After removing 25% to 30% of the total blood from each animal, multiple fluid injections were conducted. The EIT device successfully tracked changes in SV beat-to-beat during varying volume states, i.e., from hypovolemia and preload responsiveness to target volume and volume overload. From a total of 50 100-mL fluid injections on five pigs (10 injections per pig), the preload responsiveness value was as large as 32.3% in the preload responsiveness state while in the volume overload state it was as low as -4.9%. The bias of the measured SV data using EIT and PCA was 0 mL, and the limits of agreement were ±3.6 mL in the range of 17.6 mL to 51.0 mL. The results of the animal experiments suggested that EIT is capable of measuring beat-to-beat SV changes during mini-fluid challenge and determine preload responsiveness. Further animal and clinical studies will be needed to demonstrate the feasibility of the EIT method as a new tool for fluid management.

Computer-assisted Individualized Hemodynamic Management Reduces Intraoperative Hypotension in Intermediate- and High-risk Surgery: A Randomized Controlled Trial

BACKGROUND

Individualized hemodynamic management during surgery relies on accurate titration of vasopressors and fluids. In this context, computer systems have been developed to assist anesthesia providers in delivering these interventions. This study tested the hypothesis that computer-assisted individualized hemodynamic management could reduce intraoperative hypotension in patients undergoing intermediate- to high-risk surgery.

METHODS

This single-center, parallel, two-arm, prospective randomized controlled single blinded superiority study included 38 patients undergoing abdominal or orthopedic surgery. All included patients had a radial arterial catheter inserted after anesthesia induction and connected to an uncalibrated pulse contour monitoring device. In the manually adjusted goal-directed therapy group (N = 19), the individualized hemodynamic management consisted of manual titration of norepinephrine infusion to maintain mean arterial pressure within 10% of the patient's baseline value, and mini-fluid challenges to maximize the stroke volume index. In the computer-assisted group (N = 19), the same approach was applied using a closed-loop system for norepinephrine adjustments and a decision-support system for the infusion of mini-fluid challenges (100 ml). The primary outcome was intraoperative hypotension defined as the percentage of intraoperative case time patients spent with a mean arterial pressure of less than 90% of the patient's baseline value, measured during the preoperative screening. Secondary outcome was the incidence of minor postoperative complications.

RESULTS

All patients were included in the analysis. Intraoperative hypotension was 1.2% [0.4 to 2.0%] (median [25th to 75th] percentiles) in the computer-assisted group compared to 21.5% [14.5 to 31.8%] in the manually adjusted goal-directed therapy group (difference, -21.1 [95% CI, -15.9 to -27.6%]; P < 0.001). The incidence of minor postoperative complications was not different between groups (42 vs. 58%; P = 0.330). Mean stroke volume index and cardiac index were both significantly higher in the computer-assisted group than in the manually adjusted goal-directed therapy group (P < 0.001).

CONCLUSIONS

In patients having intermediate- to high-risk surgery, computer-assisted individualized hemodynamic management significantly reduces intraoperative hypotension compared to a manually controlled goal-directed approach.

EDITOR’S PERSPECTIVE

Goal-Directed Fluid Therapy and Postoperative Outcomes in an Enhanced Recovery Program for Colorectal Surgery: A Propensity Score-Matched Multicenter Study

INTRODUCTION

Goal-directed fluid therapy (GDFT) has increasingly been utilized in major surgery as a key component to ensure fluid optimization and adequate tissue perfusion, showing improvements in the rate of morbidity and mortality under conventional care. It is unclear if patients derive similar benefit as part of an enhanced recovery program (ERP). Our group sought to assess the association between GDFT and postoperative outcomes within an ERP for colorectal surgery.

METHODS

A propensity score-matched analysis, based upon demographic characteristics, comorbidities, and ERP components, was utilized to assess the association between GDFT and outcomes in a multicenter prospective ERP for colorectal surgery cohort study. Outcomes included pulmonary edema, acute kidney injury (AKI), ileus, surgical site infection (SSI), and anastomotic dehiscence. The calipmatch module was used to match patients who received GDFT to non-GDFT in a 1-to-1 propensity score fashion.

RESULTS

A total of 151 matched pairs were included in the analysis (n = 302, 23%). Both groups had comparable baseline demographics, as well as similar rates of compliance with enhanced recovery after surgery (ERAS) components. Goal-directed fluid therapy patients received significantly more colloid (237 ± 320 mL vs. 140 ± 245 mL, P < .01) than non-GDFT counterparts. Goal-directed fluid therapy was not associated with improved rates of postoperative AKI (odds ratios (OR) 1.00, 95% confidence intervals (CI) .39-2.59, P = 1.00), ileus (OR 1.40, 95% CI .82-2.41, P = .22), SSI (OR 1.06, 95% CI .54-2.08, P = .86), or length of hospital stay (LOS) (10.8 ± 8.9 vs. 11.1±13.2 days, P = .84).

CONCLUSIONS

There was no associated between GDFT and major postoperative outcomes within an ERAS program for colorectal surgery. Additional large-scale or pragmatic randomized trials are necessary to determine whether GDFT has a role in ERP for colorectal surgery.

The effect of adding goal-directed hemodynamic management for elective patients in an established enhanced recovery program for colorectal surgery: results of quasi-experimental pragmatic trial

Background

Recent literature has demonstrated that hemodynamic instability in the intraoperative period places patients at risk of poor outcomes. Furthermore, recent studies have reported that stroke volume optimization and protocolized hemodynamic management may improve perioperative outcomes, especially surgical site infection (SSI), in certain high-risk populations. However, the optimal strategy for intraoperative management of all elective patients within an enhanced recovery program remains to be elucidated.

Methods

We performed a pre-post quasi-experimental study to assess the effect of adding goal-directed hemodynamic therapy to an enhanced recovery program (ERP) for colorectal surgery on SSI and other outcomes. Three groups were compared: “Pre-ERP,” defined as historical control (before enhanced recovery program); “ERP,” defined as enhanced recovery program using zero fluid balance; and “ERP+GDHT,” defined as enhanced recovery program plus goal-directed hemodynamic therapy. Outcomes were obtained through our National Surgical Quality Improvement Program participation.

Results

A total of 623 patients were included in the final analysis (Pre-ERP = 246, ERP = 140, and ERP + GDHT = 237). Demographics and baseline clinical characteristics were balanced between groups. We did not observe statistically significant differences in SSI or composite complication rates in unadjusted or adjusted analysis. There was no evidence of association between study group and 30-day readmission. American Society of Anesthesiologists status ≥ 3 and open surgical approach were significantly associated with increased risk of SSI, composite complication, and 30-day readmission (p < 0.05 for all) in all groups.

Conclusions

There was no evidence that addition of goal-directed hemodynamic therapy for all patients in an enhanced recovery program for colorectal surgery affects the risk of SSI, composite complications, or 30-day readmission. Further research is needed to investigate whether there is benefit of goal-directed hemodynamic therapy for select high-risk populations.

Trial registration

NCT03189550. Registered 16 June 2017–Retrospectively registered, https://www.clinicaltrials.gov/ct2/results?cond=&term=NCT03189550&cntry=&state=&city=&dist=

Goal-directed haemodynamic therapy (GDHT) in surgical patients: systematic review and meta-analysis of the impact of GDHT on post-operative pulmonary complications

Background

Perioperative goal-directed haemodynamic therapy (GDHT), defined as the administration of fluids with or without inotropes or vasoactive agents against explicit measured goals to augment blood flow, has been evaluated in many randomised controlled trials (RCTs) over the past four decades. Reported post-operative pulmonary complications commonly include chest infection or pneumonia, atelectasis, acute respiratory distress syndrome or acute lung injury, aspiration pneumonitis, pulmonary embolism, and pulmonary oedema. Despite the substantial clinical literature in this area, it remains unclear whether their incidence is reduced by GDHT. This systematic review aims to determine the effect of GDHT on the respiratory outcomes listed above, in surgical patients.

Methods

We searched the Cochrane Central Register for Controlled Trials (CENTRAL), MEDLINE, EMBASE, and clinical trial registries up until January 2020. We included all RCTs reporting pulmonary outcomes. The primary outcome was post-operative pulmonary complications and secondary outcomes were specific pulmonary complications and intra-operative fluid input. Data synthesis was performed on Review Manager and heterogeneity was assessed using I² statistics.

Results

We identified 66 studies with 9548 participants reporting pulmonary complications. GDHT resulted in a significant reduction in total pulmonary complications (OR 0.74, 95% CI 0.59 to 0.92). The incidence of pulmonary infections, reported in 45 studies with 6969 participants, was significantly lower in the GDHT group (OR 0.72, CI 0.60 to 0.86). Pulmonary oedema was recorded in 23 studies with 3205 participants and was less common in the GDHT group (OR 0.47, CI 0.30 to 0.73). There were no differences in the incidences of pulmonary embolism or acute respiratory distress syndrome. Sub-group analyses demonstrated: (i) benefit from GDHT in general/abdominal/mixed and cardiothoracic surgery but not in orthopaedic or vascular surgery; and (ii) benefit from fluids with inotropes and/or vasopressors in combination but not from fluids alone. Overall, the GDHT group received more colloid (+280 ml) and less crystalloid (−375 ml) solutions than the control group. Due to clinical and statistical heterogeneity, we downgraded this evidence to moderate.

Conclusions

This systematic review and meta-analysis suggests that the use of GDHT using fluids with inotropes and/or vasopressors, but not fluids alone, reduces the development of post-operative pulmonary infections and pulmonary oedema in general, abdominal and cardiothoracic surgical patients. This evidence was graded as moderate.

PROSPERO registry reference: CRD42020170361

Hydroxyethyl starch for perioperative goal-directed fluid therapy in 2020: a narrative review

BACKGROUND

Perioperative fluid management - including the type, dose, and timing of administration -directly affects patient outcome after major surgery. The objective of fluid administration is to optimize intravascular fluid status to maintain adequate tissue perfusion. There is continuing controversy around the perioperative use of crystalloid versus colloid fluids. Unfortunately, the importance of fluid volume, which significantly influences the benefit-to-risk ratio of each chosen solution, has often been overlooked in this debate.

MAIN TEXT

The volume of fluid administered during the perioperative period can influence the incidence and severity of postoperative complications. Regrettably, there is still huge variability in fluid administration practices, both intra-and inter-individual, among clinicians. Goal-directed fluid therapy (GDFT), aimed at optimizing flow-related variables, has been demonstrated to have some clinical benefit and has been recommended by multiple professional societies. However, this approach has failed to achieve widespread adoption. A closed-loop fluid administration system designed to assist anesthesia providers in consistently applying GDFT strategies has recently been developed and tested. Such an approach may change the crystalloid versus colloid debate. Because colloid solutions have a more profound effect on intravascular volume and longer plasma persistence, their use in this more "controlled" context could be associated with a lower fluid balance, and potentially improved patient outcome. Additionally, most studies that have assessed the impact of a GDFT strategy on the outcome of high-risk surgical patients have used hydroxyethyl starch (HES) solutions in their protocols. Some of these studies have demonstrated beneficial effects, while none of them has reported severe complications.

CONCLUSIONS

The type and volume of fluid used for perioperative management need to be individualized according to the patient's hemodynamic status and clinical condition. The amount of fluid given should be guided by well-defined physiologic targets. Compliance with a predefined hemodynamic protocol may be optimized by using a computerized system. The type of fluid should also be individualized, as should any drug therapy, with careful consideration of timing and dose. It is our perspective that HES solutions remain a valid option for fluid therapy in the perioperative context because of their effects on blood volume and their reasonable benefit/risk profile.

Anesthetic Management Using Multiple Closed-loop Systems and Delayed Neurocognitive Recovery: A Randomized Controlled Trial

BACKGROUND

Cognitive changes after anesthesia and surgery represent a significant public health concern. We tested the hypothesis that, in patients 60 yr or older scheduled for noncardiac surgery, automated management of anesthetic depth, cardiac blood flow, and protective lung ventilation using three independent controllers would outperform manual control of these variables. Additionally, as a result of the improved management, patients in the automated group would experience less postoperative neurocognitive impairment compared to patients having standard, manually adjusted anesthesia.

METHODS

In this single-center, patient-and-evaluator-blinded, two-arm, parallel, randomized controlled, superiority study, 90 patients having noncardiac surgery under general anesthesia were randomly assigned to one of two groups. In the control group, anesthesia management was performed manually while in the closed-loop group, the titration of anesthesia, analgesia, fluids, and ventilation was performed by three independent controllers. The primary outcome was a change in a cognition score (the 30-item Montreal Cognitive Assessment) from preoperative values to those measures 1 week postsurgery. Secondary outcomes included a battery of neurocognitive tests completed at both 1 week and 3 months postsurgery as well as 30-day postsurgical outcomes.

RESULTS

Forty-three controls and 44 closed-loop patients were assessed for the primary outcome. There was a difference in the cognition score compared to baseline in the control group versus the closed-loop group 1 week postsurgery (-1 [-2 to 0] vs. 0 [-1 to 1]; difference 1 [95% CI, 0 to 3], P = 0.033). Patients in the closed-loop group spent less time during surgery with a Bispectral Index less than 40, had less end-tidal hypocapnia, and had a lower fluid balance compared to the control group.

CONCLUSIONS

Automated anesthetic management using the combination of three controllers outperforms manual control and may have an impact on delayed neurocognitive recovery. However, given the study design, it is not possible to determine the relative contribution of each controller on the cognition score.

Perioperative restrictive versus goal-directed fluid therapy for adults undergoing major non-cardiac surgery

BACKGROUND

Perioperative fluid management is a crucial element of perioperative care and has been studied extensively recently; however, 'the right amount' remains uncertain. One concept in perioperative fluid handling is goal-directed fluid therapy (GDFT), wherein fluid administration targets various continuously measured haemodynamic variables with the aim of optimizing oxygen delivery. Another recently raised concept is that perioperative restrictive fluid therapy (RFT) may be beneficial and at least as effective as GDFT, with lower cost and less resource utilization.

OBJECTIVES

To investigate whether RFT may be more beneficial than GDFT for adults undergoing major non-cardiac surgery.

SEARCH METHODS

We searched the following electronic databases on 11 October 2019: Cochrane Central Register of Controlled Trials, in the Cochrane Libary; MEDLINE; and Embase. Additionally, we performed a targeted search in Google Scholar and searched trial registries (World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) and ClinicalTrials.gov) for ongoing and unpublished trials. We scanned the reference lists and citations of included trials and any relevant systematic reviews identified.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) comparing perioperative RFT versus GDFT for adults (aged ≥ 18 years) undergoing major non-cardiac surgery.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened references for eligibility, extracted data, and assessed risk of bias. We resolved discrepancies by discussion and consulted a third review author if necessary. When necessary, we contacted trial authors to request additional information. We presented pooled estimates for dichotomous outcomes as risk ratios (RRs) with 95% confidence intervals (CIs), and for continuous outcomes as mean differences (MDs) with standard deviations (SDs). We used Review Manager 5 software to perform the meta-analyses. We used a fixed-effect model if we considered heterogeneity as not important; otherwise, we used a random-effects model. We used Poisson regression models to compare the average number of complications per person.

MAIN RESULTS

From 6396 citations, we included six studies with a total of 562 participants. Five studies were performed in participants undergoing abdominal surgery (including one study in participants undergoing cytoreductive abdominal surgery with hyperthermic intraperitoneal chemotherapy (HIPEC)), and one study was performed in participants undergoing orthopaedic surgery. In all studies, surgeries were elective. In five studies, crystalloids were used for basal infusion and colloids for boluses, and in one study, colloid was used for both basal infusion and boluses. Five studies reported the ASA (American Society of Anesthesiologists) status of participants. Most participants were ASA II (60.4%), 22.7% were ASA I, and only 16.9% were ASA III. No study participants were ASA IV. For the GDFT group, oesophageal doppler monitoring was used in three studies, uncalibrated invasive arterial pressure analysis systems in two studies, and a non-invasive arterial pressure monitoring system in one study. In all studies, GDFT optimization was conducted only intraoperatively. Only one study was at low risk of bias in all domains. The other five studies were at unclear or high risk of bias in one to three domains. RFT may have no effect on the rate of major complications compared to GDFT, but the evidence is very uncertain (RR 1.61, 95% CI 0.78 to 3.34; 484 participants; 5 studies; very low-certainty evidence). RFT may increase the risk of all-cause mortality compared to GDFT, but the evidence on this is also very uncertain (RD 0.03, 95% CI 0.00 to 0.06; 544 participants; 6 studies; very low-certainty evidence). In a post-hoc analysis using a Peto odds ratio (OR) or a Poisson regression model, the odds of all-cause mortality were 4.81 times greater with the use of RFT compared to GDFT, but the evidence again is very uncertain (Peto OR 4.81, 95% CI 1.38 to 16.84; 544 participants; 6 studies; very low-certainty evidence). Nevertheless, sensitivity analysis shows that exclusion of a study in which the final volume of fluid received intraoperatively was higher in the RFT group than in the GDFT group revealed no differences in mortality. Based on analysis of secondary outcomes, such as length of hospital stay (464 participants; 5 studies; very low-certainty evidence), surgery-related complications (364 participants; 4 studies; very low-certainty evidence), non-surgery-related complications (74 participants; 1 study; very low-certainty evidence), renal failure (410 participants; 4 studies; very low-certainty evidence), and quality of surgical recovery (74 participants; 1 study; very low-certainty evidence), GDFT may have no effect on the risk of these outcomes compared to RFT, but the evidence is very uncertain. Included studies provided no data on administration of vasopressors or inotropes to correct haemodynamic instability nor on cost of treatment.

AUTHORS' CONCLUSIONS

Based on very low-certainty evidence, we are uncertain whether RFT is inferior to GDFT in selected populations of adults undergoing major non-cardiac surgery. The evidence is based mainly on data from studies on abdominal surgery in a low-risk population. The evidence does not address higher-risk populations or other surgery types. Larger, higher-quality RCTs including a wider spectrum of surgery types and a wider spectrum of patient groups, including high-risk populations, are needed to determine effects of the intervention.

Lack of impact of nil-per-os (NPO) time on goal-directed fluid delivery in first case versus afternoon case starts: a retrospective cohort study

BACKGROUND

Goal Directed Fluid Therapy (GDFT) represents an objective fluid replacement algorithm. The effect of provider variability remains a confounder. Overhydration worsens perioperative morbidity and mortality; therefore, the impact of the calculated NPO deficit prior to the operating room may reach harm.

METHODS

A retrospective single-institution study analyzed patients at UC Irvine Medical Center main operating rooms from September 1, 2013 through September 1, 2015 receiving GDFT. The primary study question asked if GDFT suggested different fluid delivery after different NPO periods, while reducing inter-provider variability. We created two patient groups distinguished by 0715 surgical start time or start time after 1200. We analyzed fluid administration totals with either a 1:1 crystalloid to colloid ratio or a 3:1 ratio. We performed direct group-wise testing on total administered volume expressed as total ml, total ml/hr., and total ml/kg/hr. between the first case start (AM) and afternoon case (PM) groups. A linear regression model included all baseline covariates that differed between groups as well as plausible confounding factors for differing fluid needs. Finally, we combined all patients from both groups, and created NPO time to total administered fluid scatterplots to assess the effect of patient-reported NPO time on fluid administration.

RESULTS

Whether reported by total administered volume or net fluid volume, and whether we expressed the sum as ml, ml/hr., or ml/kg/hr., the AM group received more fluid on average than the PM group in all cases. In the general linear models, for all significant independent variables evaluated, AM vs PM case start did not reach significance in both cases at p = 0.64 and p = 0.19, respectively. In scatterplots of NPO time to fluid volumes, absolute adjusted and unadjusted R2 values are < 0.01 for each plot, indicating virtually non-existent correlations between uncorrected NPO time and fluid volumes measured.

CONCLUSIONS

This study showed NPO periods do not influence a patient's volume status just prior to presentation to the operating room for surgical intervention. We hope this data will influence the practice of providers routinely replacing calculated NPO period volume deficit; particularly with those presenting with later surgical case start times.

Pleth variability index versus pulse pressure variation for intraoperative goal-directed fluid therapy in patients undergoing low-to-moderate risk abdominal surgery: a randomized controlled trial

Background

Goal-directed fluid therapy (GDFT) based on dynamic indicators of fluid responsiveness has been shown to decrease postoperative complications and hospital length of stay (LOS) in patients undergoing major abdominal surgery. The usefulness of this approach still needs to be clarified in low-to-moderate risk abdominal surgery. Both pulse-pressure variation (PPV) and pleth variability index (PVI) can be used to guide GDFT strategies. The objective of this prospective randomized controlled trial was to determine if the use of PVI guided GDFT, when compared to PPV guided GDFT, would lead to similar hospital LOS in patients undergoing low-to-moderate risk surgery. Secondary outcomes included amount of fluid administered and incidence of postoperative complications.

Methods

Patients were randomized into either PVI or PPV guided GDFT groups. Both received a baseline 2 ml kg^− 1 h^− 1 Lactated Ringer infusion. Additional fluid boluses consisted of 250 mL of colloid that was infused over a 10 min period if PVI was > 15% or PPV was > 13% for at least five minutes. The primary outcome was to determine if hospital LOS, which was defined as the number of days from surgery up to the day the surgeon authorized hospital discharge, was equivalent between the two groups.

Results

A total of 76 patients were included and they were randomized into two groups of 38 patients. Baseline characteristics were similar in both groups. Both PVI and PPV guided GDFT strategies were equivalent for the primary outcome of LOS (median [interquartile range]) (days) 2.5 [2.0–3.3] vs. 3.0 [2.0–5.0], p = 0.230, respectively. Fluids infused, postoperative complications, and all other outcomes were not different between groups.

Conclusion

In patients undergoing low-to-moderate risk abdominal surgery, PVI seems to guide GDFT similarly to PPV in regards to hospital LOS, amount of fluid, and incidence of postoperative complications. However, in low-risk patients undergoing these surgical procedures optimizing stroke volume may have limited impact on outcome.

Trial registration

ClinicalTrials.gov Identifier: NCT02908256, September 2016, retrospectively registered.

Electronic supplementary material

The online version of this article (10.1186/s12871-019-0707-9) contains supplementary material, which is available to authorized users.