Restrictive intraoperative fluid optimisation algorithm improves outcomes in patients undergoing pancreaticoduodenectomy: A prospective multicentre randomized controlled trial

Intraoperative hemodynamic management during pancreatoduodenectomy - an analysis of 525 patients

IMPORTANCE

Optimization of perioperative hemodynamic management during major pancreatic surgery can reduce postoperative complications.

OBJECTIVE

In this study, we aimed to investigate the effect of intraoperative hemodynamic management, in consideration of both anesthesiologic and surgery-related aspects on major short-term complications following partial pancreatoduodenectomy (PD).

DESIGN, SETTING AND PARTICIPANTS

Data of 525 patients undergoing PD between January 2017 and December 2018 at the Heidelberg University Hospital were retrospectively analyzed.

MAIN OUTCOMES AND MEASURES

Primary outcome was a composite of 90-day mortality, pancreatic fistula and completion pancreatectomy. Logistic regression was performed to estimate the impact of anesthesiologic and surgical factors. Furthermore, patients were stratified by the amount of fluid administered intraoperatively and the maximum catecholamine dose to examine the impact on the primary endpoint.

RESULTS

Using logistic regression analysis we demonstrated that epidural anesthesia was associated with a reduction in the occurrence of the combined endpoint (OR 0.568; CI 0.331-0.973), this effect was primarily driven by a lower rate of completion pancreatectomy. The intraoperative administration of fresh frozen plasma (FFP) doubled the odds of the occurrence of the primary endpoint (OR 2.238; CI 1.290-3.882). The comparison of patients with and without FFP transfusion showed that all components of the primary endpoint were more frequent in the FFP group. Complication rates in the stratified fluid groups showed a U-shaped curve with the least amount of complications in patients who received 6.5 to 8 ml/kg/h of intraoperative fluid. The comparison of maximum norepinephrine doses revealed the same pattern with the least complication rate in the low-intermediate dose range (0.05-0.08 µg/kg/min and 0.08-0.11 µg/kg/min).

CONCLUSIONS AND RELEVANCE

Epidural anesthesia had a beneficial effect on the rate of major surgical complications following PD, whereas intraoperative FFP transfusion showed a negative association. Intraoperative hemodynamic management appears to have a major impact on perioperative mortality and morbidity with a U-shaped relation for both fluid and vasopressor dose.

Intraoperative Goal-Directed Fluid Therapy and Outcomes After Oncologic Surgeries: A Systematic Review and Meta-Analysis

BACKGROUND

Surgery is the first-line curative treatment for most solid-organ malignancies. During major surgeries, fluid under- or over administration can have a significant impact on recovery and postoperative outcomes. For patients undergoing oncologic surgery, delayed recovery or complications could additionally impact subsequent oncologic treatment planning. This systematic review and meta-analysis aims to evaluate the impact of goal-directed fluid therapy (GDFT) on perioperative outcomes after oncologic surgeries.

METHODS

We systematically searched PubMed, EMBASE, CINAHL, and Web of Science citation index for clinical trials comparing the GDFT to routine clinical care. The primary outcomes of interest are the hospital length of stay and the total incidence of postoperative complications. Secondary outcomes include organ-specific complications and recovery of bowel function.

RESULTS

The literature search was last updated on February 17, 2024. We identified a total of 24 randomized controlled trials (RCTs) comparing GDFT to routine care with 1172 and 1186 patients, respectively. The GDFT arm had a significantly shorter length of hospital stay (mean difference [MD], 1.57 days, 95% confidence interval [CI], -2.29 to -0.85, P < .01), as well as lower incidence of complications (risk ratio, 0.74, 95% CI, 0.56-0.97, P = .03). The GDFT arm also had a shorter time to bowel function recovery (MD, 0.58 days, 95% CI, -1.02 to -0.14, P = .01). None of the included trials reported the longer-term oncologic outcomes. The overall certainty of evidence is low due to between-study variance and study risk of bias. Trial sequence analysis indicates that further studies are unlikely to alter the conclusion regarding postoperative length of stay but may provide further information on the postoperative complications.

CONCLUSIONS

Our systematic review and meta-analysis suggests that in oncologic surgery, intraoperative GDFT significantly reduces the length of hospital stay, lowers the risk of complications, and facilitates bowel function recovery. Further studies are required to evaluate whether the improvement in early postoperative outcomes leads to better long-term oncologic outcomes.

Intraoperative goal-directed hemodynamic therapy targeting both arterial pressure and flow parameters using uncalibrated pulse contour techniques: A meta-analysis of randomized controlled trials

BACKGROUND

Goal-directed haemodynamic therapy (GDHT) aims to optimize haemodynamic variables. However, its effectiveness in reducing postoperative complications in major abdominal surgery, particularly when targeting both arterial pressure and flow variables, remains unclear. This meta-analysis addresses this by evaluating GDHT using uncalibrated pulse contour (uPC) methods.

METHODS

We conducted a systematic review and meta-analysis of randomized controlled trials (RCT) in adult patients undergoing major abdominal surgery who received GDHT using uncalibrated pulse contour (uPC) methods for cardiac output monitoring, with predefined targets for both blood flow and blood pressure. The primary outcome was postoperative complications; secondary outcomes included postoperative acute kidney injury (AKI), hospital length of stay (EH), intraoperative fluid administration and mortality.

RESULTS

Initial search retrieved 860 reports, with 12 RCTs (1367 patients) meeting the inclusion criteria. Our meta-analysis showed a significant reduction in postoperative complications (RR 0.78, 95% CI 0.68-0.90), AKI (RR 0.7, 95% CI 0.51-0.97), and hospital LOS (SMD -0.30, 95% CI -0.54 to -0.06) with uPC-guided GDHT. No significant differences were observed in intraoperative fluid volume and mortality.

CONCLUSIONS

Implementing GDHT in major abdominal surgery with predefined arterial pressure and blood flow targets significantly reduces postoperative morbidity and hospital EH without increasing intraoperative fluid administration.

Systematic review and meta-analysis of goal-directed haemodynamic therapy algorithms during surgery for the prevention of surgical site infection

Background

Surgical site infection (SSI) is the most common postoperative complication. Goal-directed haemodynamic therapy (GDHT) may help to prevent SSI, but recommendations for its use initially have been set at conditional because of low-certainty evidence at the time. An updated systematic review with SSI as the primary endpoint has not been performed since 2011, and important new evidence has emerged. We assessed the influence of GDHT on SSI and other postoperative outcomes.

Methods

We searched Ovid/MEDLINE, Excerpta Medica Database (Embase.com), and Cochrane library from inception up to September 2024 for randomised controlled trials comparing the effect of any GDHT algorithm to conventional fluid therapy on SSI incidence in adult patients undergoing surgery and analysed eligible data using random effects. We conducted several subgroup analyses, including the risk of bias (RoB), and a trial sequential analysis (TSA). We evaluated the certainty of evidence using Grading of Recommendations, Assessment, Development, and Evaluations. This study is registered with PROSPERO, CRD42022277535.

Findings

We found 75 studies that met the inclusion criteria with an incidence of 1,478 SSI among 13,010 patients (11.4%). The incidence of SSI was reduced from 13.3% in the conventional fluid therapy to 9.4% after GDHT (absolute risk reduction 3.9%); pooled relative risk 0.71 (95% CI 0.62-0.81). Subgroup analysis for the low RoB studies revealed comparable results. Meta-regression indicated no strong evidence for individual subgroup effects. In the TSA, the cumulative z-line crossed the boundary for effect.

Interpretation

High-certainty evidence indicates that GDHT reduces the risk of SSI when compared to conventional fluid therapy in adults undergoing surgery. New studies are unlikely to change this outcome. These findings justify a stronger recommendation for the use of GDHT.

Funding

Dutch Association for Quality Funds Medical Specialists.

Treatment strategies to prevent or mitigate the outcome of postpancreatectomy hemorrhage: a review of randomized trials

BACKGROUND

Postpancreatectomy hemorrhage (PPH) is a leading cause for surgical mortality after pancreatic surgery. Several strategies for the prevention and management of PPH have been studied in randomized controlled trials (RCTs) but a systematic review is lacking. The authors systematically reviewed RCTs regarding the impact of treatment strategies on the incidence and outcome of PPH.

MATERIAL AND METHODS

Eligible RCTs reporting on impact of treatment on the rate of PPH were identified through a systematic literature search using the Evidence Map of Pancreatic Surgery (2012-2022). Methodological quality was assessed using the Cochrane Risk of Bias 2 (RoB-2) tool for RCTs. Various definitions of PPH were accepted and outcome reported separately for the International Study Group for Pancreatic Surgery (ISGPS) definition.

RESULTS

Overall, 99 RCTs fulfilled the eligibility criteria with a pooled 6.1% rate of PPH (range 1-32%). The pooled rate of PPH defined as ISGPS grade B/C was 8.1% (range 0-24.9%). Five RCTs reported five strategies that significantly reduced the rate of PPH. Three concerned surgical technique: pancreatic anastomosis with small jejunal incision, falciform ligament wrap around the gastroduodenal artery stump, and pancreaticojejunostomy (vs pancreaticogastrostomy). Two concerned perioperative management: perioperative pasireotide administration, and algorithm-based postoperative patient management. No single RCT specifically focused on the treatment of patients with PPH.

CONCLUSION

This systematic review of RCTs identified five strategies which reduce the rate of PPH; three concerning intraoperative surgical technique and two concerning perioperative patient management. Future studies should focus on the treatment of patients with PPH as RCTs are currently lacking.

Intraoperative fluid management is not predictive of AKI in major pancreatic surgery: a retrospective cohort study

BACKGROUND

Pancreatic surgery is associated with a significant risk for acute kidney injury (AKI) and clinically relevant postoperative pancreatic fistula (CR-POPF). This investigation evaluated the impact of intraoperative volume administration, vasopressor therapy, and blood pressure management on the primary outcome of AKI and the secondary outcome of a CR-POPF after pancreatic surgery.

METHODS

This retrospective single-center cohort investigated 200 consecutive pancreatic surgeries (January 2018-December 2021). Patients were categorized for the presence/absence of AKI (Kidney Disease Improving Global Outcomes) and CR-POPF. After univariate analysis, multivariable models were constructed to control for the univariate cofactor differences in the primary and secondary outcomes.

RESULTS

AKI was identified in 20 patients (10%) with significant univariate differences in demographics (body mass index and gender), comorbidities, indices of chronic renal insufficiency, and an increased AKI Risk score. Surgical characteristics, intraoperative fluid, vasopressor, and blood pressure management were similar in patients with and without AKI. Patients with AKI had increased blood loss, lower urine output, and packed red blood cell administration. After multivariate analysis, male gender (OR = 7.9, 95% C.I. 1.8-35.1) and the AKI Risk score (OR = 6.3, 95% C.I. 2.4-16.4) were associated with the development of AKI (p < 0.001). Intraoperative and postoperative volume, vasopressor administration, and intraoperative hypotension had no significant impact in the multivariate analysis. CR-POPF occurred in 23 patients (11.9%) with no significant contributing factors in the multivariate analysis. Patients who developed AKI or a CR-POPF had an increase in surgical complications, length of stay, discharge to a skilled nursing facility, and mortality.

CONCLUSION

In this analysis, intraoperative volume administration, vasopressor therapy, and a blood pressure < 55 mmHg for more than 10 min were not associated with an increased risk of AKI. After multivariate analysis, male gender and an elevated AKI Risk score were associated with an increased likelihood of AKI.

The effect of an intraoperative patient-specific, surgery-specific haemodynamic algorithm in improving textbook outcomes for hepatobiliary-pancreatic surgery: a multicentre retrospective study

BACKGROUND

The concept of a "textbook outcome" is emerging as a metric for ideal surgical outcomes. We aimed to evaluate the impact of an advanced haemodynamic monitoring (AHDM) algorithm on achieving a textbook outcome in patients undergoing hepatobiliary-pancreatic surgery.

METHODS

This retrospective, multicentre observational study was conducted across private and public teaching sectors in Victoria, Australia. We studied patients managed by a patient-specific, surgery-specific haemodynamic algorithm or via usual care. The primary outcome was the effect of using a patient-specific, surgery-specific AHDM algorithm for achieving a textbook outcome, with adjustment using propensity score matching. The textbook outcome criteria were defined according to the International Expert Delphi Consensus on Defining Textbook Outcome in Liver Surgery and Nationwide Analysis of a Novel Quality Measure in Pancreatic Surgery.

RESULTS

Of the 780 weighted cases, 477 (61.2%, 95% CI: 57.7%-64.6%) achieved the textbook outcome. Patients in the AHDM group had a higher rate of textbook outcomes [n = 259 (67.8%)] than those in the Usual care group [n = 218 (54.8%); p < 0.001, estimated odds ratio (95% CI) 1.74 (1.30-2.33)]. The AHDM group had a lower rate of surgery-specific complications, severe complications, and a shorter hospital length of stay (LOS) [OR 2.34 (95% CI: 1.30-4.21), 1.79 (95% CI: 1.12-2.85), and 1.83 (95% CI: 1.35-2.46), respectively]. There was no significant difference between the groups for hospital readmission and mortality.

CONCLUSIONS

AHDM use was associated with improved outcomes, supporting its integration in hepatobiliary-pancreatic surgery. Prospective trials are warranted to further evaluate the impact of this AHDM algorithm on achieving a textbook impact on long-term outcomes.

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.

Risk factors for acute kidney injury after pancreatoduodenectomy, and association with postoperative complications and death

BACKGROUND

Acute kidney injury (AKI) is associated with increased morbidity and mortality after general surgery, although little is known among patients undergoing pancreatoduodenectomy. The objective was to investigate the association between AKI and postoperative complications and death after pancreatoduodenectomy.

METHODS

All patients ≥18 years who underwent a pancreatoduodenectomy 2008-2019 at the Karolinska University Hospital, Stockholm, Sweden, were included. Standardized criteria for AKI, including estimated glomerular filtration rate (eGFR) and urine volume measurements, were used to grade postoperative AKI.

RESULTS

In total, 970 patients were included with a median age of 68 years (IQR 61-74) of whom 517 (53.3%) were men. There were 137 (14.1%) patients who developed postoperative AKI. Risk factors for AKI included lower preoperative eGFR, cardiovascular disease and treatment with renin-angiotensin system inhibitors or diuretics. Those who developed AKI had a higher risk of severe postoperative complications, including Clavien-Dindo score ≥ IIIa (adjusted OR 3.35, 95% CI 2.24-5.01) and ICU admission (adjusted OR 7.83, 95% CI 4.39-13.99). In time-to-event analysis, AKI was associated with an increased risk for both 30-day mortality (adjusted HR 4.51, 95% CI 1.54-13.27) and 90-day mortality (adjusted HR 4.93, 95% CI 2.37-10.26). Patients with benign histology and AKI also had an increased 1-year mortality (HR 4.89, 95% CI 1.88-12.71).

CONCLUSIONS

Postoperative AKI was associated with major postoperative complications and an increased risk of postoperative mortality. Monitoring changes in serum creatinine levels and urine volume output could be important in the immediate perioperative period to improve outcomes after pancreatoduodenectomy.

Optimal Perioperative Fluid Therapy Associates with Fewer Complications After Pancreaticoduodenectomy

BACKGROUND

Optimal fluid management in pancreaticoduodenectomy patients remains contested. We aimed to examine the association between perioperative fluid administration and postoperative complications.

METHODS

We studied 168 pancreaticoduodenectomy patients operated in 2015 (n = 93) or 2017 (n = 75) at Helsinki University Hospital. In 2015, patients received intraoperative fluids following a goal-directed approach and, in 2017, according to anesthesiologist's clinical practice (conventional fluid management). We analyzed the differences in perioperative fluid administration between the groups, specifically examining the occurrence of severe complications (Clavien-Dindo ≥ III), pancreatic fistulas, cardiovascular complications, and the length of hospital stay.

RESULTS

The goal-directed group received more intraoperative fluids than the conventional fluid management group (12.0 ml/kg/h vs. 8.3 ml/kg/h, p < 0.001). Urine output (770 ml vs. 575 ml, p = 0.004) and intraoperative fluid balance (9.4 ml/kg/h vs. 6.3 ml/kg/h, p < 0.001) were higher in the goal-directed group than in the conventional fluid management group. Severe surgical complications (19.4% vs. 38.7%, p = 0.009) as well as clinically relevant pancreatic fistulas (1.1% vs. 10.7%, p = 0.011) occurred more frequently in patients receiving conventional fluid management. Moreover, the conventional fluid management group experienced longer hospital stays (9.0 vs. 11.5 days, p = 0.02). Lower intraoperative fluid volume accompanying conventional fluid management was associated with a higher risk of severe postoperative complications compared with higher volume in the goal-directed group (odds ratio 2.58 (95% confidence interval 1.04-6.42), p = 0.041).

CONCLUSIONS

The goal-directed group experienced severe complications less frequently. Our findings indicate that optimizing the intraoperative fluid administration benefits patients, while adopting a too-restrictive approach represents an inferior choice.

The clinical impact of the systolic volume variation guided intraoperative fluid administration regimen on surgical outcomes after pancreaticoduodenectomy: a retrospective cohort study

BACKGROUND

Pancreaticoduodenectomy is associated with high morbidity. Many preoperative variables are risk factors for postoperative complications, but they are primarily non-modifiable. It is not clear whether an intraoperative goal-directed fluid regimen might be associated with fewer postoperative surgical complications compared to current conservative, non-goal-directed fluid practices. We hypothesize that the use of Systolic Volume Variation (SVV)-guided intraoperative fluid administration might be beneficial.

METHODS

Data from 223 patients who underwent pancreaticoduodenectomy in our institution between 2015 and 2019 were reviewed. Patients were classified into two groups based on the use of intraoperative use of SVV to guide the administration of fluids. The decision to use SVV or not was made by the attending anesthesiologist. Subjects were classified into SVV-guided intraoperative fluid therapy (SVV group) and non-SVV-guided intraoperative fluid therapy (non-SVV group). Uni and multivariate regression analyses were conducted to determine if SVV-guided fluid therapy was significantly associated with a lower incidence of postoperative surgical complications, such as Postoperative Pancreatic Fistula (POPF), Delayed Gastric Emptying (DGE), among others, after adjusting for confounders.

RESULTS

Baseline, demographic, and intraoperative characteristics were similar between SVV and non-SVV groups. In the multivariate analysis, the use of SVV guidance was significantly associated with fewer postoperative surgical complications (OR = 0.48; 95% CI 0.25-0.91; p = 0.025), even after adjusting for significant covariates, such as perioperative use of epidural, pancreatic gland parenchyma texture, and diameter of the pancreatic duct.

CONCLUSIONS

VV-guided intraoperative fluid administration might be associated with fewer postoperative surgical complications after pancreaticoduodenectomy.

Intraoperative Respiratory and Hemodynamic Strategies for Reducing Nausea, Vomiting, and Pain after Surgery: Systematic Review and Meta-Analysis

BACKGROUND

Despite improved medical treatment strategies, post-operative pain, nausea, and vomiting remain major challenges. This systematic review investigated the relationship between perioperative respiratory and hemodynamic interventions and postoperative pain, nausea, and vomiting.

METHODS

PubMed and Embase were searched on March 8, 2021 for randomized clinical trials investigating the effect of perioperative respiratory or hemodynamic interventions in adults undergoing non-cardiac surgery. Investigators reviewed trials for relevance, extracted data, and assessed risk of bias. Meta-analyses were performed when feasible. GRADE was used to assess the certainty in the evidence.

RESULTS

This review included 65 original trials; of these 48% had pain, nausea and/or vomiting as the primary focus. No reduction of postoperative pain was found in meta-analyses when comparing recruitment maneuvers with no recruitment, high (80%) to low (30%) fraction of oxygen, low (5-7 ml/kg) to high (9-12 ml/kg) tidal volume, or goal-directed hemodynamic therapy to standard care. In the meta-analysis comparing recruitment maneuvers with no recruitment maneuvers, patients undergoing laparoscopic gynecological surgery had less shoulder pain 24 hours postoperatively (mean difference in the numeric rating scale from 0 to 10: -1.1, 95% CI: -1.7, -0.5). In meta-analyses, comparing high to low fraction of inspired oxygen and goal-directed hemodynamic therapy to standard care in patients undergoing abdominal surgery, the risk of postoperative nausea and vomiting was reduced (odds ratio: 0.45, 95% CI: 0.24, 0.87 and 0.48, 95% CI: 0.27, 0.85). The certainty in the evidence was mostly very low to low. The results should be considered exploratory given the lack of pre-specified hypotheses and corresponding risk of Type 1 errors.

CONCLUSION

There is limited evidence regarding the impact of intraoperative respiratory and hemodynamic interventions on postoperative pain or nausea and vomiting. More definitive trials are needed to guide clinical care within this area. This article is protected by copyright. All rights reserved.

The Effect of Goal-Directed Fluid Administration on Outcomes After Pancreatic Surgery

BACKGROUND

We evaluated the effect of an Enhanced Recovery After Surgery protocol on intraoperative fluid administration and postoperative outcomes in pancreatic surgery.

METHODS

Pancreatic cancer resections at our institution from 2012 to 2018 were grouped according to pre- or post-protocol initiation. Preoperative characteristics and postoperative outcomes were compared with Fisher's exact test and chi-square for categorical variables, and Mann-Whitney U test for continuous variables. Further analysis separated patients that had a Whipple from those who had distal pancreatectomy.

RESULTS

A total of 263 patients underwent pancreatic cancer resection during the study period (169 Whipples, 84 DPs, 92 pre-ERAS and 171 post-ERAS). Intraoperative fluid administration significantly decreased after protocol implementation (mean 6,277 ml vs. 3870 ml, p < 0.001). This held true when separating patients that had a Whipple procedure from those that had a DP (6,929 ml vs. 4,513 ml, p < 0.001, 5,060 ml vs. 2,833 cc, p = 0.002, respectively). Intensive care unit (ICU) admission (41.3% vs. 20.5%, p < 0.001) and length of stay (9.4 vs. 8.1 days, p < 0.01) were significantly reduced after ERAS implementation for all patients and in Whipple patients alone (47.5% vs. 23.6%, p = 0.002 and 10.7 vs. 6.6 days, p = 0.004). DP patients also had significantly decreased ICU admissions (41.3% vs. 20.5%, p = 0.045). All other postoperative outcomes were not significantly different.

CONCLUSION

For patients undergoing pancreatic cancer resection, goal-directed fluid management is associated with decreased intraoperative fluid administration, decreased ICU admission, and decreased length of stay without an increase in postoperative complications or readmission.

Pain management, fluid therapy and thromboprophylaxis after pancreatoduodenectomy: a worldwide survey among surgeons

BACKGROUND

The aim of this survey was to assess practices regarding pain management, fluid therapy and thromboprophylaxis in patients undergoing pancreatoduodenectomy on a global basis.

METHODS

This survey study among surgeons from eight (inter)national scientific societies was performed according to the CHERRIES guideline.

RESULTS

Overall, 236 surgeons completed the survey. ERAS protocols are used by 61% of surgeons and respectively 82%, 93%, 57% believed there is a relationship between pain management, fluid therapy, and thromboprophylaxis and clinical outcomes. Epidural analgesia (50%) was most popular followed by intravenous morphine (24%). A restrictive fluid therapy was used by 58% of surgeons. Chemical thromboprophylaxis was used by 88% of surgeons. Variations were observed between continents, most interesting being the choice for analgesic technique (transversus abdominis plane block was popular in North America), restrictive fluid therapy (little use in Asia and Oceania) and duration of chemical thromboprophylaxis (large variation).

CONCLUSION

The results of this international survey showed that only 61% of surgeons practice ERAS protocols. Although the majority of surgeons presume a relationship between pain management, fluid therapy and thromboprophylaxis and clinical outcomes, variations in practices were observed. Additional studies are needed to further optimize, standardize and implement ERAS protocols after pancreatic surgery.

Goal-directed haemodynamic therapy during general anaesthesia for noncardiac surgery: a systematic review and meta-analysis

BACKGROUND

During general anaesthesia for noncardiac surgery, there remain knowledge gaps regarding the effect of goal-directed haemodynamic therapy on patient-centred outcomes.

METHODS

Included clinical trials investigated goal-directed haemodynamic therapy during general anaesthesia in adults undergoing noncardiac surgery and reported at least one patient-centred postoperative outcome. PubMed and Embase were searched for relevant articles on March 8, 2021. Two investigators performed abstract screening, full-text review, data extraction, and bias assessment. The primary outcomes were mortality and hospital length of stay, whereas 15 postoperative complications were included based on availability. From a main pool of comparable trials, meta-analyses were performed on trials with homogenous outcome definitions. Certainty of evidence was evaluated using Grading of Recommendations, Assessment, Development, and Evaluations (GRADE).

RESULTS

The main pool consisted of 76 trials with intermediate risk of bias for most outcomes. Overall, goal-directed haemodynamic therapy might reduce mortality (odds ratio=0.84; 95% confidence interval [CI], 0.64 to 1.09) and shorten length of stay (mean difference=-0.72 days; 95% CI, -1.10 to -0.35) but with low certainty in the evidence. For both outcomes, larger effects favouring goal-directed haemodynamic therapy were seen in abdominal surgery, very high-risk surgery, and using targets based on preload variation by the respiratory cycle. However, formal tests for subgroup differences were not statistically significant. Goal-directed haemodynamic therapy decreased risk of several postoperative outcomes, but only infectious outcomes and anastomotic leakage reached moderate certainty of evidence.

CONCLUSIONS

Goal-directed haemodynamic therapy during general anaesthesia might decrease mortality, hospital length of stay, and several postoperative complications. Only infectious postoperative complications and anastomotic leakage reached moderate certainty in the evidence.

MEasuring the impact of Anesthetist-administered medications volumeS on intraoperative flUid balance duRing prolonged abdominal surgEry (MEASURE Study)

BACKGROUND

The contribution of intraoperative anesthetist-administered medications (IAAMs) to the total volume of intraoperative intravenous (IV) fluid therapy and their association with postoperative outcomes has never been formally investigated.

METHODS

We performed a retrospective study of adult patients undergoing pancreaticoduodenectomy. The volume of IAAMs, crystalloids and colloids, blood and blood products, blood loss, urine output and intraoperative fluid balance were collected. The contribution of IAAMs to the total intraoperative IV fluid volume and postoperative complications was evaluated.

RESULTS

A total of 152 consecutive patients were included. The median volume of IAAMs was 363.8 mL (interquartile range [IQR], (241.0-492.5) delivered at a median rate of 0.61 mL kg hr^-1 (0.40-0.87) over a median duration of surgery of 489 minutes (416.3-605.3). This increased the total administered fluid volume by 5.2% (95% confidence intervals [CI]: 4.6, 5.9%) (Cohen's d=1.33, P<0.001). The volume of IAAMs was comparable to the intraoperative colloid volume administered (median colloid volume, 400 mL). Overall, fluid volumes correlated significantly with the severity of complications (P=0.011), and the correlation strength increased when the IAAMs volume was included (P=0.005). On addition of IAAMs, the area under the receiver operator characteristic curve for prediction of postoperative complications increased from 0.580 (95%CI: 0.458, 0.701) to 0.603 (95%CI: 0.483, 0.723), P=0.041).

CONCLUSIONS

IAAMs significantly increased the total administered fluid volume during pancreaticoduodenectomy. Their inclusion increases the accuracy of postoperative complications predictions. These findings support their inclusion in fluid volumes and balances in future interventional studies.

Preemptive Administration of Albumin during Pancreatectomy Does Not Reduce Postoperative Complications: A Prospective Randomized Controlled Trial

Despite the empirical use of human albumin during pancreatectomy to replace intraoperative volume loss while preventing fluid overload and edema, its impact on postoperative outcomes remains unclear. In addition, most previous studies have focused on the effects of therapeutic albumin usage. Here, we investigated whether preemptive administration of human albumin to prevent edema during pancreatectomy could reduce the incidence of moderate postoperative complications. Adult patients undergoing pancreatectomy were assigned to either the albumin group (n = 100) or the control group (n = 100). Regardless of the preoperative albumin level, 200 mL of 20% albumin was administered to the albumin group after induction of anesthesia. The primary outcome was the incidence of moderate postoperative complications as defined by a Clavien–Dindo classification grade ≥ 2 at discharge. Intraoperative net-fluid balance, a known risk factor of postoperative complication after pancreatectomy, was lower in the albumin group than in the control group (p = 0.030), but the incidence of moderate postoperative complications was not different between the albumin and control groups (47/100 vs. 38/100, respectively; risk ratio: 1.24, 95% CI: 0.89 to 1.71; p = 0.198). Therefore, preemptive administration of human albumin to prevent fluid overload and edema during pancreatectomy is not recommended because of its lack of apparent benefit in improving postoperative outcomes.

Unfavorable effect of high postoperative fluid balance on outcome of pancreaticoduodenectomy

Purpose

Despite the many efforts to overcome postoperative complications, pancreaticoduodenectomy (PD) is still accompanied with considerable concerns of lethal complications. The clinical factors are known to affect postoperative outcomes such as diameter of pancreatic duct, texture of pancreas, and comorbidity of the patients are mostly uncorrectable. Thus, investigation for correctable risk factors is required. Recently, perioperative fluid volume was reported to be associated with complications after PD. This study aims to determine the relationship between postoperative fluid balance and surgical outcome after open PD.

Methods

We reviewed, retrospectively, 172 consecutive patients who underwent open PD in a single institution between 2015 and 2019. The status of perioperative fluid balance 2 days after surgery and clinical factors were investigated to determine the association with postoperative outcome including postoperative pancreatic fistula (POPF). According to postoperative fluid balance, patients were divided into high- and low-balance groups, and clinical features and surgical outcomes were compared between both groups. Multivariate analysis were performed to identify risk factors for POPF.

Results

The percentage of morbidity and the incidence of POPF were higher in the high-balance group compared to the low-balance group (61.6% vs. 37.2%, P = 0.001; 15.1% vs. 3.5%, P = 0.009). High postoperative fluid balance and the presence cardiovascular disease were correlated with POPF on multivariate analysis (odds ratio [OR], 4.574; 95% confidence interval [CI], 1.229–17.029; P = 0.023 and OR, 3.517; 95% CI, 1.209–12.017; P = 0.045).

Conclusion

Higher amount of postoperative fluid balance and the presence of cardiovascular disease are associated with POPF after PD.

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.

[Perioperative fluid management in major abdominal surgery]

Intravascular fluid administration belongs to the cornerstones of perioperative treatment with a substantial impact on surgical outcome especially with respect to major abdominal surgery. By avoidance of hypovolemia and hypervolemia, adequate perioperative fluid management significantly contributes to the reduction of insufficient tissue perfusion as a determinant of postoperative morbidity and mortality. The effective use of intravascular fluids requires detailed knowledge of the substances as well as measures to guide fluid therapy. Fluid management already starts preoperatively and should be continued in the postoperative setting (recovery room, peripheral ward) considering a patient-adjusted and surgery-adjusted hemodynamic monitoring. Communication between all team members participating in perioperative care is essential to optimize fluid management.

Association between perioperative fluid administration and postoperative outcomes: a 20-year systematic review and a meta-analysis of randomized goal-directed trials in major visceral/noncardiac surgery

Background

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.

Methods

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 h after the admission in the critical care unit (perioperative fluid).

Results

The metanalysis included 21 RCTs enrolling 2729 patients with a median amount of perioperative fluid infusion of 4500 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 = 0.23 and 54.8% vs. 39.8%; p value = 0.09, respectively].

Overall, GDT reduced the overall rate of postoperative complications, as compared to controls [pooled risk difference (95% CI) = − 0.10 (− 0.14, − 0.07); Chi₂ = 30.97; p value < 0.0001], but not to a reduction of perioperative mortality [pooled risk difference (95%CI) = − 0.016 (− 0.0334; 0.0014); p value = 0.07]. Considering the rate of organ-related postoperative events, GDT did not reduce neither renal (p value = 0.52) nor cardiovascular (p value = 0.86) or pulmonary (p value = 0.14) or neurological (p value = 0.44) or infective (p value = 0.12) complications.

Conclusions

Irrespectively to the amount of perioperative fluid administered, GDT strategy reduces postoperative complications, but not perioperative mortality.

Trial Registration

CRD42020168866; Registration: February 2020

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=168866

Intraoperative fluid management in hepato-biliary-pancreatic operation using stroke volume variation monitoring: A single-center, open-label, randomized pilot study

TRIAL DESIGN

This investigator-initiated, single-center, open-label, parallel-group, randomized-controlled pilot study was designed to compare the intraoperative fluid balance and perioperative complications in patients undergoing hepato-biliary-pancreatic surgery with or without stroke volume variation (SVV)-guided fluid management.

METHODS

Patients who were aged >18 years and underwent elective major hepato-biliary-pancreatic surgery between June 30, 2015, and August 31, 2016 at our center were randomly assigned to receive SVV-guided or conventional fluid therapy. The intervention group used SVV to determine the patients' volume status. The primary outcome was the total fluid balance per body weight per operation time, and the secondary outcomes were the total amount of intravenous infusion per body weight per operation time and the Sequential Organ Failure Assessment score on postoperative day 1. Patients were randomized by a two-block computer-generated assignment sequence. Masking of patients and assessors was conducted. The patients and assessors were each blinded to the details of the trial; however, the clinicians were not.

RESULTS

Of the 69 patients who were initially eligible, 60 provided informed consent for participation in the study. After randomization, three patients dropped out of the study because of deviations from the protocol or unexpected hypotension, leaving 28 and 29 patients in the intervention and control groups, respectively. Patients in both groups had similar characteristics at baseline. The median (interquartile range [IQR]) intraoperative fluid balance in the control and SVV groups was 6.2 (IQR, 4.9-7.9) and 8.1 (IQR, 5.7-10.5) ml/kg/h, respectively (P = .103). The administered intravenous infusion was significantly higher in the SVV group (median, 10.9; IQR, 8.3-15.3 ml/kg/h) than in the control group (median, 9.5; IQR, 7.7-10.3 ml/kg/h) (P = .011). On postoperative day 1, the PaO2/FiO2 ratio was lower in the SVV group (median, 266; IQR, 261-341) than in the control group (median, 346; IQR, 299-380) (P = .019).

CONCLUSIONS

Use of the SVV-guided fluid management protocol did not reduce intraoperative fluid balance but increased the intraoperative fluid administration and might worsen postoperative oxygenation.

TRIAL REGISTRATION

UMIN000018111.

Effect of the Type of Intraoperative Restrictive Fluid Management on the Outcome of Pancreaticoduodenectomy: A Systematic Review and Meta-Analysis

Background. The perioperative management of pancreaticoduodenectomy is complicated, and the significant morbidity and mortality may be influenced by the method of intraoperative fluid management. Whether intraoperative restrictive fluid therapy can affect the outcomes of pancreaticoduodenectomy or not is controversial. Methods. PubMed, EMBASE, Cochrane Library, and clinicaltrials.gov were searched for prospective and retrospective studies comparing restrictive and liberal intraoperative fluids in patients undergoing pancreaticoduodenectomy. Following study identification, a systematic review and meta-analysis were performed. Results. Fourteen studies, including six prospective trials and eight retrospective studies, involving 2,596 patients, were included. Intraoperative restrictive fluid regimens had no effect on the mortality compared to liberal fluid regimens in the overall cohort (odds ratio [OR]: 1.39; 95% confidence interval [CI]: 0.82–2.35, $p=0.773$ ). Liberal fluid regimens could increase the risk of pulmonary adverse events (OR: 1.66; 95% CI: 1.10–2.50, $p=0.131$ ) and prolong the length of hospital stay (SMD -0.10; 95% CI -0.19– -0.01, $p=0.375$ ). There were no significant differences in the incidence of pancreatic fistulas. Conclusions. Restrictive fluid regimens have a slight effect on the outcomes of pancreaticoduodenectomy. The clinical relevance of this finding needs to be interpreted. The existing evidence may not be adequate; therefore, further studies are warranted.

Perioperative fluids and complications after pancreatoduodenectomy within an enhanced recovery pathway

Optimized fluid management is a key component of enhanced recovery (ERAS) pathways. Implementation is challenging for pancreatoduodenectomy (PD) and clear guidance is missing in the respective protocol. The aim of this retrospective study was to evaluate the influence of perioperative intravenous (IV) fluid administration on postoperative complications. 164 consecutive patients undergoing PD within ERAS between October 2012 and June 2017 were included. Perioperative IV fluid and morbidity (Clavien classification and comprehensive complication index (CCI)) were assessed. A threshold of more than 4400 ml IV fluid during the first 24 h could be identified to predict occurrence of complications (area under ROC curve 0.71), with a positive and negative predictive value of 93 and 23% respectively. More than 4400 ml intravenous fluids during the first 24 h was an independent predictor of overall postoperative complications (adjusted odds ratio 4.40, 95% CI 1.47–13.19; p value = 0.008). Patients receiving ≥ 4400 ml were associated with increased overall complications (94 vs 77%; p value < 0.001), especially pulmonary complications (31 vs 16%; p value = 0.037), as well as a higher median CCI (33.7 vs 26.2; p value 0.041). This threshold of 4400 ml intravenous fluid might be a useful indicator for the management following pancreatoduodenectomy.

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

Intraoperative Fluid Management in Patients Undergoing Spine Surgery: A Narrative Review

Fluid management has been widely recognized as an important component of the perioperative care in patients undergoing major procedures including spine surgeries. Patient- and surgery-related factors such as age, length of the surgery, massive intraoperative blood loss, and prone positioning, may impact the intraoperative administration of fluids. In addition, the type of fluid administered may also affect post-operative outcomes. Published literature describing intraoperative fluid management in patients undergoing major spine surgeries is limited and remains controversial. Therefore, we reviewed current literature on intraoperative fluid management and its association with post-operative complications in spine surgery.

Persistent severe post-operative hypotension after pancreaticoduodenectomy is related to increased inflammatory response

BACKGROUND

Hypotension during major surgery is frequent, resulting in increased need for observation in the post-anaesthesia care unit and treatment including vasopressors and fluids. However, although severe hypotension in the immediate post-operative recovery phase after major surgery is suggested to be related to increased morbidity and mortality, the underlying risk factors are not well described, hindering advancements in prevention and treatment.

METHODS

We performed a retrospective study assessing factors (age, gender, body-mass index, cardiac co-morbidity, haemoglobin, absolute and increase in c-reactive protein on the first post-operative day, bleeding, fluid balance at the end of surgery and the first post-operative day) related to severe persistent hypotension (SPH) (SPH: need for noradrenaline to maintain a mean arterial blood pressure (MAP) >65.0 mm Hg on the morning after surgery) and occurrence of other early (24 hours) complications. One hundred patients undergoing pancreaticoduodenectomy (PD) with pre-operative high-dose glucocorticoid and goal-directed fluid therapy were enrolled and perioperative data collected from anaesthetic and medical records.

RESULTS

Forty-five patients had SPH, who had a significantly higher increase in CRP levels the morning after surgery (median 50 mg L^-1 vs 41 mg L^-1 , SPH vs non-SPH, respectively, P = .028), and a significantly more positive fluid balance at discharge (median 1457 ml vs 1031 ml, respectively, P = .027) vs patients without SPH.

CONCLUSIONS

Severe persistent hypotension after PD was associated with significantly increased inflammatory response and increased need for fluids. Future studies should investigate the effect of further inflammatory control in PD to improve haemodynamics and morbidity.

Systematic review and meta-analysis of the perioperative use of vasoactive drugs on postoperative outcomes after major abdominal surgery

BACKGROUND

The perioperative use of vasoactive drugs is ubiquitous in clinical anaesthesia; yet, the drugs, doses, and haemodynamic targets used are highly variable. Our objectives were to determine whether the perioperative administration of vasoactive drugs reduces mortality, morbidity, and length of stay in adult patients (aged 16 yr or older) undergoing major abdominal surgery.

METHODS

MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were searched for peer-reviewed RCTs with no language or date restrictions. Studies that assessed the intraoperative use of vasoactive drugs were included. Title, abstract, and full-text screening was performed. Risk of bias for each outcome measure was conducted. We calculated the risk ratio (RR) using the Mantel-Haenszel random-effects model with corresponding 95% confidence interval (CI) for dichotomous outcomes, and mean difference using the inverse variance random-effects model with corresponding 95% CI for continuous outcomes.

RESULTS

Twenty-six studies (5561 participants) were included. There was no difference in mortality at the longest follow-up with an RR of 0.84 (95% CI: 0.63-1.12; P=0.23). The intervention significantly reduced the number of patients with one or more postoperative complications; RR: 0.76 (95% CI: 0.66-0.88; P=0.0002). Hospital length of stay was reduced by 0.91 days in the intervention group.

CONCLUSIONS

This review is limited by the quality and sample size of individual studies, and the heterogeneity of the settings, interventions, and outcome measures. Perioperative administration of vasoactive drugs may reduce postoperative complications and hospital length of stay in adult patients having major abdominal surgery.

Goal-Directed vs Traditional Approach to Intraoperative Fluid Therapy during Open Major Bowel Surgery: Is There a Difference?

Introduction

Optimum perioperative fluid therapy is important to improve the outcome of the surgical patient. This study prospectively compared goal-directed intraoperative fluid therapy with traditional fluid therapy in general surgical patients undergoing open major bowel surgery.

Methodology

Patients between 20 and 70 years of age, either gender, ASA I and II, and scheduled for elective open major bowel surgery were included in the study. Patients who underwent laparoscopic and other surgeries were excluded. After routine induction of general anaesthesia, the patients were randomised to either the control group (traditional fluid therapy), the FloTrac group (based on stroke volume variation), or the PVI group (based on pleth variability index). Fluid input and output, recovery characteristics, and complications were noted.

Results

306 patients, with 102 in each group, were enrolled. Five patients (control (1), FloTrac (2), and PVI (2)) were inoperable and were excluded. Demographic data, ASA PS, anaesthetic technique, duration of surgery, and surgical procedures were comparable. The control group received significantly more crystalloids (3200 ml) than the FloTrac (2000 ml) and PVI groups (1875 ml), whereas infusion of colloids was higher in the FloTrac (400–700 ml) and PVI (200–500 ml) groups than in the control group (0–500 ml). The control group had significantly positive net fluid balance intraoperatively (2500 ml, 9 ml/kg/h) compared to the FloTrac (1515 ml, 5.4 ml/kg/h) and PVI (1420 ml, 6 ml/kg/h) groups. Days to ICU stay, HDU stay, return of bowel movement, oral intake, morbidity, duration of hospital stay, and survival rate were comparable. The total number of complications was not different between the three groups. Anastomotic leaks occurred more often in the Control group than in the others, but the numbers were small.

Conclusions

Use of goal-directed fluid management, either with FloTrac or pleth variability index results in a lower volume infusion and lower net fluid balance. However, the complication rate is similar to that of traditional fluid therapy. This trial is registered with CTRI/2018/04/013016.

Perioperative Fluid Restriction in Abdominal Surgery: A Systematic Review and Meta-analysis

BACKGROUND

Perioperative fluid management is a critical component in patients undergoing abdominal surgery. However, the benefit of restricted fluid regimen remains inconclusive. This systematic review aimed to explore potential factors causing these inconsistent findings.

METHODS

The literature searches were performed in three databases including PubMed, Embase, and the Cochrane library until August 30, 2018. Only randomized, controlled trials comparing the effect of restricted versus liberal regimen in abdominal surgery were included. The primary outcome was total postoperative complications. Subgroup analysis was performed according to between-group weight increase difference (≥ 2 kg and < 2 kg) and fluid intake ratio (≥ 1.8 and < 1.8).

RESULTS

Sixteen studies were finally included in this meta-analysis. The benefit of the restricted regimen in reducing postoperative complication was only significant in the subgroup with high weight increase difference (≥ 2 kg) (RR 0.67, 95% CI 0.57-0.79) and the subgroup with high fluid intake ratio (≥ 1.8) (RR 0.72, 95% CI 0.62-0.82). In the subgroup with low weight increase difference (< 2 kg) or low fluid intake ratio (< 1.8), the effect of the restricted regimen was not significant (RR 0.88, 95% CI 0.51-1.50, and RR 1.18, 95% CI 0.91-1.53, respectively).

CONCLUSIONS

The benefit of the restricted regimen was only significant in the subgroup with high weight increase difference (≥ 2 kg) or high fluid intake ratio (≥ 1.8).

Impact of a goal directed fluid therapy algorithm on postoperative morbidity in patients undergoing open right hepatectomy: a single centre retrospective observational study

Background

Right hepatectomy is a complex procedure that carries inherent risks of perioperative morbidity. To evaluate outcome differences between a low central venous pressure fluid intervention strategy and a goal directed fluid therapy (GDFT) cardiac output algorithm we performed a retrospective observational study. We hypothesized that a GDFT protocol would result in less intraoperative fluid administration, reduced complications and a shorter length of hospital stay.

Methods

Patients undergoing hepatectomy using an established enhanced recovery after surgery (ERAS) programme between 2010 and 2017 were extracted from a prospectively managed electronic hospital database. Inclusion criteria included adult patients, undergoing open right (segments V-VIII) or extended right (segments IV-VIII) hepatectomy. Primary outcome: amount of intraoperative fluid administration used between the two groups. Secondary outcomes: type and amount of vasoactive medications used, the development of predefined postoperative complications, hospital length of stay, and 30-day mortality. Complications were defined by the European Perioperative Clinical Outcome definitions and graded according to Clavien-Dindo classification. The association between GDFT and the amount of fluid and vasoactive medication used was investigated using logistic and linear regression models.

Results

Fifty-eight consecutive patients were identified. 26 patients received GDFT and 32 received Usual care. There were no significant differences in baseline patient characteristics. Less intraoperative fluid was used in the GDFT group: median (IQR) 2000 ml (1175 to 2700) vs. 2750 ml (2000 to 4000) in the Usual care group; p = 0.03. There were no significant differences in the use of vasoactive medications. Postoperative complications were similar: 9 patients (35%) in the GDFT group vs. 18 patients (56%) in the Usual care group; p = 0.10, OR: 0.41; (95%CI: 0.14 to 1.20). Median (IQR) length of stay for patients in the GDFT group was 7 days (6:8) vs. 9 days (7:13) in the Usual care group; incident rate ratio 0.72 (95%CI: 0.56 to 0.93); p = 0.012. There was no difference in perioperative mortality.

Conclusions

In patients undergoing open right hepatectomy with an established ERAS programme, use of GDFT was associated with less intraoperative fluid administration and reduced hospital length of stay when compared to Usual care. There were no significant differences in postoperative complications or mortality.

Trial registration

Australian New Zealand Clinical Trials Registry: no12619000558123 on 10/4/19.

Goal directed fluid therapy for major liver resection: A multicentre randomized controlled trial

Background

The effect a restrictive goal directed therapy (GDT) fluid protocol combined with an enhanced recovery after surgery (ERAS) programme on hospital stay for patients undergoing major liver resection is unknown.

Methods

We conducted a multicentre randomized controlled pilot trial evaluating whether a patient-specific, surgery-specific intraoperative restrictive fluid optimization algorithm would improve duration of hospital stay and reduce perioperative fluid related complications.

Results

Forty-eight participants were enrolled. The median (IQR) length of hospital stay was 7.0 days (7.0:8.0) days in the restrictive fluid optimization algorithm group (Restrict group) vs. 8.0 days (6.0:10.0) in the conventional care group (Conventional group) (Incidence rate ratio 0.85; 95% Confidence Interval 0.71:1.1; p = 0.17). No statistically significant difference in expected number of complications per patient between groups was identified (IRR 0.85; 95%CI: 0.45–1.60; p = 0.60). Patients in the Restrict group had lower intraoperative fluid balances: 808 mL (571:1565) vs. 1345 mL (900:1983) (p = 0.04) and received a lower volume of fluid per kg/hour intraoperatively: 4.3 mL/kg/hr (2.6:5.8) vs. 6.0 mL/kg/hr (4.2:7.6); p = 0.03. No significant differences in the proportion of patients who received vasoactive drugs intraoperatively (p = 0.56) was observed.

Conclusion

In high-volume hepatobiliary surgical units, the addition of a fluid restrictive intraoperative cardiac output-guided algorithm, combined with a standard ERAS protocol did not significantly reduce length of hospital stay or fluid related complications. Our findings are hypothesis-generating and a larger confirmatory study may be justified.

•

Major liver resection is a complex procedure with up to 40% patients experiencing complications.

•

Optimisation of perfusion and oxygen delivery to all organs remain the cornerstone of best hemodynamic care.

•

Traditionally, a low central venous pressure strategy during major liver resection has been used to reduce venous bleeding.

•

The impact of a restrictive cardiac output fluid optimisation algorithm during major liver surgery is unknown.

•

After major hepatobiliary surgery, a fluid restrictive algorithm did not reduce length of hospital stay or complications.

Hemodynamic goal-directed therapy and postoperative kidney injury: an updated meta-analysis with trial sequential analysis

Background

Perioperative goal-directed therapy (GDT) reduces the risk of renal injury. However, several questions remain unanswered, such as target, kind of patients and surgery, and role of fluids and inotropes. We therefore update a previous analysis, including all studies published in the meanwhile, to clarify the clinical impact of this strategy on acute kidney injury.

Main body

Randomized controlled trials enrolling adult patients undergoing major surgery were considered. GDT was defined as perioperative monitoring and manipulation of hemodynamic parameters to reach normal or supranormal values by fluids alone or with inotropes. Trials comparing the effects of GDT and standard hemodynamic therapy were considered. Primary outcome was acute kidney injury, whichever definition was used. Meta-analytic techniques (analysis software RevMan, version 5.3) were used to combine studies, using random-effect odds ratios (OR) and 95% confidence intervals (CI). Trial sequential analyses were performed including all trials and considering only low risk of bias trials. Sixty-five trials with an overall sample of 9308 patients were included. OR for the development of renal injury was 0.64 (95% CI, 0.62–0.87; p = 0.0003), with no statistical heterogeneity. Trial sequential analyses and sensitivity analysis including studies with low risk of bias confirmed the main results. A significant decrease in renal injury rate was observed in studies that adopted cardiac output and oxygen delivery as hemodynamic target and that used both fluids and inotropes. The postoperative kidney injury rate was significantly lower in trials enrolling “high-risk” patients and major abdominal and orthopedic surgery.

Short conclusion

The present meta-analysis suggests that targeting GDT to perioperative systemic oxygen delivery, by means of fluids and inotropes, can be the best way to improve renal perfusion and oxygenation in high-risk patients undergoing major abdominal and orthopedic surgery.

Electronic supplementary material

The online version of this article (10.1186/s13054-019-2516-4) contains supplementary material, which is available to authorized users.

Intraoperative Fluid Administration and Surgical Outcomes Following Pancreaticoduodenectomy: External Validation at a Tertiary Referral Center

BACKGROUND

While intraoperative fluid overload is associated with higher complication rates following surgery, data for pancreaticoduodenectomy are scarce and heterogeneous. We evaluated multiple prior definitions of restrictive and liberal fluid regimens and analyzed whether these affected surgical outcomes at our tertiary referral center.

METHODS

Studies evaluating different intraoperative fluid regimens on outcomes after pancreatic resections were retrieved. After application of all prior definitions of restrictive and liberal fluid regimens to our patient cohort, relative risks of each outcome were calculated using all reported infusion regimens.

RESULTS

Five hundred and seven pancreaticoduodenectomies were included. Nine different fluid regimens were evaluated. Two regimens utilized absolute volume cutoffs, and the remaining evaluated various infusion rates, ranging from 5 to 15 mL/kg/h. Total volume administration of >5000 mL and >6000 mL was associated with increased complications (RR 1.25 and RR 1.17, respectively) and >6000 mL with increased sepsis (RR 2.14). Conversely, a rate of <5 mL/kg/h was associated with increased risk of postoperative pancreatic fistula (POPF, RR 3.16) and sepsis (RR 3.20), <6.8 mL/kg/h with increased major morbidity (RR 1.64) and sepsis (RR 2.27), and <8.2 mL/kg/h with increased POPF (RR 2.16). No effects were observed on pulmonary complications, surgical site infections, length of stay, or mortality.

CONCLUSIONS

In an uncontrolled setting with no standard intraoperative or postoperative care map, the volume of intraoperative fluid administration appears to have limited impact on early postoperative outcomes following pancreaticoduodenectomy, with adverse outcomes only seen at extreme values.

Population-based volume kinetics of Ringer's lactate solution in patients undergoing open gastrectomy

In order to maintain stable blood pressure and heart rate during surgery, anesthesiologists need to administer the appropriate amount of fluid with appropriate fluid type to the patient, then quantifying how fluid is distributed and eliminated from the body is useful for establishing a fluid administration strategy. In this study we characterized the volume kinetics of Ringer's lactate solution in patients undergoing open gastrectomy. When propofol and remifentanil reached a pseudosteady state at the target concentration and blood pressure was stabilized following surgical stimulation, enrolled patients were administered 1000 mL of Ringer's lactate solution for 20 min, followed by continuous infusion at a rate of 6 mL/kg/h until the time of the last blood collection for volume kinetic analysis. Arterial blood samples were collected to measure the hemoglobin concentration at different time points. The change in hemoglobin-derived plasma dilution induced by the administration of Ringer's lactate solution was evaluated by nonlinear mixed effects modeling. Three hundred and twenty-three plasma dilution data points from 27 patients were used to determine the pharmacokinetic characteristics of Ringer's lactate solution. A two-volume model best described the pharmacokinetics of Ringer's lactate solution. The mean arterial pressure (MAP) and body weight (WT) were significant covariates for the elimination clearance (k_r) and central volume of distribution at baseline (V_c0), respectively. The parameter estimates were as follows: k_r (mL/min) = 124 + (MAP/70)^14.2, V_c0 (mL) = 0.95 + 3440 × (WT/63), V_t0 (mL) = 2730, and k_t (mL/min) = 181. A higher MAP was associated with a greater elimination clearance and, consequently, less water accumulation in the interstitium. As body weight increases, volume expansion in the blood vessels increases.

Choice of fluids in critically ill patients

Background

Fluids are by far the most commonly administered intravenous treatment in patient care. During critical illness, fluids are widely administered to maintain or increase cardiac output, thereby relieving overt tissue hypoperfusion and hypoxia.

Main text

Until recently, because of their excellent safety profile, fluids were not considered “medications”. However, it is now understood that intravenous fluid should be viewed as drugs. They affect the cardiovascular, renal, gastrointestinal and immune systems. Fluid administration should therefore always be accompanied by careful consideration of the risk/benefit ratio, not only of the additional volume being administered but also of the effect of its composition on the physiology of the patient. Apart from the need to constantly assess fluid responsiveness, it is also important to periodically reconsider the type of fluid being administered and the evidence regarding the relationship between specific disease states and different fluid solutions.

Conclusions

The current review presents the state of the art regarding fluid solutions and presents the existing evidence on routine fluid management of critically ill patients in specific clinical settings (sepsis, Adult Respiratory Distress Syndrome, major abdominal surgery, acute kidney injury and trauma).

Electronic supplementary material

The online version of this article (10.1186/s12871-018-0669-3) contains supplementary material, which is available to authorized users.

Clinical Implications of Intraoperative Fluid Therapy in Pancreatic Surgery

BACKGROUND

Recent studies have suggested that intraoperative fluid overload is associated with a worse outcome after major abdominal surgery. However, evidence in the field of pancreatic surgery is still not consistent. The aim of this study was to evaluate whether intraoperative fluid management could affect the outcome of a major pancreatic resection.

METHODS

Prospective analysis of 350 major pancreatic resections performed in 2016 at the Department of General and Pancreatic Surgery-The Pancreas Institute, University of Verona Hospital Trust. Patients were dichotomized according to intraoperative fluid volume administration (near-zero vs. liberal fluid balance) and matched using propensity score. Intraoperative fluid administration was then correlated to the postoperative outcome.

RESULTS

Liberal fluid balance was associated with an increased rate of Clavien-Dindo ≥ IIIB both after pancreaticoduodenectomy (60.3 vs. 30.2%, p < 0.01) and distal pancreatectomy (50 vs. 27.1%, p = 0.03). In case of pancreaticoduodenectomy, liberal fluid balance was also associated with an increased rate of pancreatic fistula (33.3 vs. 19.9%, p = 0.05), but when considering patients with soft remnants, an increase rate of pancreatic fistula (52.8 vs. 23%, p = 0.03) was indeed associated with the near-zero fluid balance.

CONCLUSION

Considering all pancreatic resections, a liberal fluid balance is associated with an increased rate of postoperative morbidity. However, in the case of PD with a soft pancreas, an NZF balance could lead to pancreatic stump ischemia and anastomotic failure. Intraoperative fluid management should be managed according to patient's pancreas-specific risk factors.

Is goal-directed fluid therapy based on dynamic variables alone sufficient to improve clinical outcomes among patients undergoing surgery? A meta-analysis

Background

Whether goal-directed fluid therapy based on dynamic predictors of fluid responsiveness (GDFTdyn) alone improves clinical outcomes in comparison with standard fluid therapy among patients undergoing surgery remains unclear.

Methods

PubMed, EMBASE, the Cochrane Library and ClinicalTrials.gov were searched for relevant studies. Studies comparing the effects of GDFTdyn with that of standard fluid therapy on clinical outcomes among adult patients undergoing surgery were considered eligible. Two analyses were performed separately: GDFTdyn alone versus standard fluid therapy and GDFTdyn with other optimization goals versus standard fluid therapy. The primary outcomes were short-term mortality and overall morbidity, while the secondary outcomes were serum lactate concentration, organ-specific morbidity, and length of stay in the intensive care unit (ICU) and in hospital.

Results

We included 37 studies with 2910 patients. Although GDFTdyn alone lowered serum lactate concentration (mean difference (MD) − 0.21 mmol/L, 95% confidence interval (CI) (− 0.39, − 0.03), P = 0.02), no significant difference was found between groups in short-term mortality (odds ratio (OR) 0.85, 95% CI (0.32, 2.24), P = 0.74), overall morbidity (OR 1.03, 95% CI (0.31, 3.37), P = 0.97), organ-specific morbidity, or length of stay in the ICU and in hospital. Analysis of trials involving the combination of GDFTdyn and other optimization goals (mainly cardiac output (CO) or cardiac index (CIx)) showed a significant reduction in short-term mortality (OR 0.45, 95% CI (0.24, 0.85), P = 0.01), overall morbidity (OR 0.41, 95% CI (0.28, 0.58), P < 0.00001), serum lactate concentration (MD − 0.60 mmol/L, 95% CI (− 1.04, − 0.15), P = 0.009), cardiopulmonary complications (cardiac arrhythmia (OR 0.58, 95% CI (0.37, 0.92), P = 0.02), myocardial infarction (OR 0.35, 95% CI (0.16, 0.76), P = 0.008), heart failure/cardiovascular dysfunction (OR 0.31, 95% CI (0.14, 0.67), P = 0.003), acute lung injury/acute respiratory distress syndrome (OR 0.13, 95% CI (0.02, 0.74), P = 0.02), pneumonia (OR 0.4, 95% CI (0.24, 0.65), P = 0.0002)), length of stay in the ICU (MD − 0.77 days, 95% CI (− 1.07, − 0.46), P < 0.00001) and in hospital (MD − 1.18 days, 95% CI (− 1.90, − 0.46), P = 0.001).

Conclusions

It was not the optimization of fluid responsiveness by GDFTdyn alone but rather the optimization of tissue and organ perfusion by GDFTdyn and other optimization goals that benefited patients undergoing surgery. Patients managed with the combination of GDFTdyn and CO/CI goals might derive most benefit.

Electronic supplementary material

The online version of this article (10.1186/s13054-018-2251-2) contains supplementary material, which is available to authorized users.

Impact of postoperative intravenous fluid administration on complications following elective hepato-pancreato-biliary surgery

BACKGROUND

The impact of perioperative intravenous fluid administration on surgical outcomes has been documented in literature, but not specifically studied in the context of hepato-pancreato-biliary (HPB) surgery. This study aimed to investigate the impact of postoperative intravenous fluid administration on intensive care unit (ICU), in this subgroup of patients.

METHODS

A single-center retrospective cohort of 241 HPB patients was assessed, focusing on intravenous fluid administration in ICU, during the first 24 h. Intravenous fluid variables were compared to hospital stay and postoperative complications. Data were assessed using Spearman's correlation test for bivariate correlations and logistic regression for multivariate analysis.

RESULTS

The median volume of intravenous fluid administered in the first 24 h postoperatively was 4380 mL, of which 2200 mL was crystalloid, 1500 mL colloid and 680 mL "other" fluid. Patients with one or more complications had a higher median total intravenous fluid input (4790 vs. 4300 mL), higher colloid volume (2000 vs. 1500 mL), lower urine output (1595 vs. 1900 mL) and greater overall fluid balance (+3040 vs.+2553 mL) than those without complications. There were correlations between total intravenous fluid volume administered (r = 0.278, P < 0.001), intravenous colloid input (r = 0.278, P < 0.001), urine output (r = -0.295, P < 0.001), positive fluid balance (r = 0.344, P < 0.001) and length of hospital stay. Logistic regression model was constructed to predict the occurrence of one or more complications; total intravenous fluid volume and overall fluid balance were both independent significant predictors (OR = 2.463, P = 0.007; OR = 1.001, P = 0.011; respectively).

CONCLUSIONS

Administration of high volumes of intravenous fluids in the first 24 hours post-HPB surgery, along with higher positive fluid balance is associated with a higher rate of complications and longer hospital stay. Moreover, lower urine output is associated with longer hospital stay. Whether these are the cause of complications or the result of them remains unclear.

Association of conflicts of interest with the results and conclusions of goal-directed hemodynamic therapy research: a systematic review with meta-analysis

PURPOSE

The association between conflicts of interest (COI) and study results or article conclusions in goal-directed hemodynamic therapy (GDHT) research is unknown.

METHODS

Randomized controlled trials comparing GDHT with usual care were identified. COI were classified as industry sponsorship, author conflict, device loaner, none, or not reported. The association between COI and study results (complications and mortality) was assessed using both stratified meta-analysis and mixed effects meta-regression. The association between COI and an article's conclusion (graded as GDHT-favorable, neutral, or unfavorable) was investigated using logistic regression.

RESULTS

Of the 82 eligible articles, 43 (53%) had self-reported COI, and 50 (61%) favored GDHT. GDHT significantly reduced complications on the basis of the meta-analysis of studies with any type of COI, studies declaring no COI, industry-sponsored studies, and studies with author conflict but not on studies with a device loaner. However, no significant relationship between COI and the relative risk (GDHT vs. usual care) of developing complications was found on the basis of meta-regression (p = 0.25). No significant effect of GDHT was found on mortality. COI had a significant overall effect (p = 0.016) on the odds of having a GDHT-favorable vs. neutral conclusion based on 81 studies. Eighty-four percent of the industry-sponsored studies had a GDHT-favorable conclusion, while only 27% of the studies with a device loaner had the same conclusion grade.

CONCLUSIONS

The available evidence does not suggest a close relationship between COI and study results in GDHT research. However, a potential association may exist between COI and an article's conclusion in GDHT research.

Effects of perioperative goal-directed fluid therapy combined with the application of alpha-1 adrenergic agonists on postoperative outcomes: a systematic review and meta-analysis

Background

Past studies have demonstrated that goal-directed fluid therapy (GDFT) may be more marginal than previously believed. However, beneficial effects of alpha-1 adrenergic agonists combined with appropriate fluid administration is getting more and more attention. This study aimed to systematically review the effects of goal-directed fluid therapy (GDFT) combined with the application of alpha-1 adrenergic agonists on postoperative outcomes following noncardiac surgery.

Methods

This meta-analysis included randomized controlled trials (RCTs) on GDFT combined with the application of alpha-1 adrenergic agonists in patients undergoing noncardiac surgery. The primary outcomes included the postoperative mortality rate and length of hospital stay (LOS). The secondary outcome indexes were the incidence of postoperative complications and recovery of postoperative gastrointestinal (GI) function. The traditional pairwise meta-analysis was conducted to compare the effect of fluid therapy. The quality of included RCTs was evaluated according to the Cochrane Collaboration’s risk-of-bias tool. Also, the publication bias was detected using funnel plots, Egger’s regression test, and Begg’s adjusted rank correlation test. The meta-analysis was conducted using the RevMan 5.3 and Stata 14.0 software.

Results

Thirty-two eligible RCTs were included in this meta-analysis. Perioperative GDFT combined with the application of alpha-1 adrenergic agonists was associated with a significant reduction in LOS (P = 0.002; I² = 69%), and overall complication rates (P = 0.04; I² = 41%). It facilitated gastrointestinal function recovery, as demonstrated by shortening the time to first flatus by 6.30 h (P < 0.00001; I² = 91%) and the time to toleration of solid food by 1.69 days (P < 0.00001; I² = 0%). Additionally, there was no significant reduction in short-term mortality in the GDFT combined with alpha-1 adrenergic agonists group (P = 0.05; I² = 0%).

Conclusion

This systematic review of available evidence suggested that the use of perioperative GDFT combined with alpha-1 adrenergic agonists might facilitate recovery in patients undergoing noncardiac surgery.

Electronic supplementary material

The online version of this article (10.1186/s12871-018-0564-y) contains supplementary material, which is available to authorized users.

Intraoperative fluid management: Past and future, where is the evidence?

Currently, there is no consensus about the optimum intraoperative fluid therapy strategy. There is growing body of evidence supports the beneficial effects of adopting “Goal-directed therapy” over either the “liberal” or “restrictive” fluid therapy strategies. In this narrative review, we have presented the evidence to support the optimum strategy for intraoperative therapy. In conclusion, whatever the intravenous fluid replacement strategy used, the anesthesiologist must be prepared to adjust the composition and rate of the fluids administered to provide sufficient intravascular fluid volume for adequate perfusion of vital organs without overwhelming the glycocalyx function with fluid overloads.

Associations of Fluid Amount, Type, and Balance and Acute Kidney Injury in Patients Undergoing Major Surgery

Fluid administration has been reported to be associated with an increased risk of acute kidney injury (AKI). We assessed whether, after correction for fluid balance, amount and chloride content of fluids administered have an independent association with AKI. We performed an observational study in patients after major surgery assessing the independent association of AKI with volume, chloride content and fluid balance, after adjustment for Physiological and Operative Severity Score for enUmeration of Mortality and morbidity (POSSUM) score, age, elective versus emergency surgery, and duration of surgery. We studied 542 consecutive patients undergoing major surgery. Of these, 476 patients had renal function tested as part of routine clinical care and 53 patients (11.1%) developed postoperative AKI. After adjustments, a 100 ml greater mean daily fluid balance was artificially associated with a 5% decrease in the instantaneous hazard of AKI: adjusted Hazard Ratio (aHR) 0.951, 95% confidence intervals (CI) 0.935 to 0.967, P <0.001. However, after adjustment for the proportion of chloride-restrictive fluids, mean daily fluid amounts and balances, POSSUM morbidity, age, duration and emergency status of surgery, and the confounding effect of fluid balance, every 5% increase in the proportion of chloride-liberal fluid administered was associated with an 8% increase in the instantaneous hazard of AKI (aHR 1.079, 95% CI 1.032 to 1.128, P=0.001), and a 100 ml increase in mean daily fluid amount given was associated with a 6% increase in the instantaneous hazard of AKI (aHR 1.061, 95% CI 1.047 to 1.075, P <0.001). After adjusting for key risk factors and for the confounding effect of fluid balance, greater fluid administration and greater administration of chloride-rich fluid were associated with greater risk of AKI.