Perioperative fluid restriction in major abdominal surgery: systematic review and meta-analysis of randomized, clinical trials. World J Surg. 2013;37:1193-1202. [PMID: 23463399 DOI: 10.1007/s00268-013-1987-8]

The incidences of nausea and vomiting after general anesthesia with remimazolam versus sevoflurane: a prospective randomized controlled trial

BACKGROUND

Postoperative nausea and vomiting (PONV) refers to nausea and vomiting that occurs within 24-h after surgery or in the post-anesthesia care unit (PACU). Previous studies have reported that the use of remimazolam, a newer benzodiazepine (BDZ) hypnotic, for anesthesia results in less PONV. In this study, we compared the rate of PONV between sevoflurane and remimazolam after general anesthesia.

METHODS

In this prospective randomized controlled trial, participants aged 20-80 years who underwent elective laparoscopic cholecystectomy or hemicolectomy were randomized to either the remimazolam or sevoflurane group. The primary outcome was PONV incidence for 24-h after surgery. Secondary outcomes comprised of PONV at 30-min post-surgery, postoperative additional antiemetic use, and Quality of Recovery-15 (QOR-15) score at 24-h postoperatively.

RESULTS

Forty patients were enrolled in the study. The remimazolam group exhibited significantly lower rates of PONV for 24-h after surgery than did the sevoflurane group (remimazolam group vs. sevoflurane group; 5% vs. 45%, P = 0.003, respectively). The use of dexamethasone, a rescue antiemetic administered within 24 h of surgery, was substantially lower in the remimazolam group than in the sevoflurane group (0% in remimazolam vs. 30% in sevoflurane, P = 0.020). The QOR-15 score at 24-h after surgery showed no significant difference between the two groups.

CONCLUSIONS

Compared to sevoflurane, opting for remimazolam as an intraoperative hypnotic may decrease the incidence of PONV and reduce antiemetic use for 24 h after laparoscopic surgery.

Effect of perioperative fluid volume restriction on the incidence of complications following pancreaticoduodenectomy

BACKGROUND

Perioperative fluid restriction has been suggested to reduce morbidity and length of stay. The purpose of this study was to compare the morbidity following pancreaticoduodenectomy (PD) between fluid restriction group and conventional management group.

METHODS

Seventy-two patients were enrolled for perioperative fluid restriction of PD. During the operation, main fluid was infused at a rate of less than 8 mL/kg/hr. Until POD#3, 10% dextrose and Hartmann's solution were administered at rates of 40 mL/h and {(1.5*body weight) - 42} mL/h, respectively. The historical control group consisted of 139 patients. We compared the rates of major complication (Clavien-Dindo grade III to V) and clinically relevant postoperative pancreatic fistula (CR-POPF), length of hospital stays (LOS), amount of urine output, and the rate of acute kidney injury (AKI).

RESULTS

The rates of major complication (19.0% versus 18.7%; p > 0.999), CR-POPF (15.5% versus 15.1%; p > 0.999), and LOS (19 days [range: 10-52] versus 19 days [range: 11-75]; p = 0.514) were comparable in the study and the control group, respectively. Amount of urine output during the operation and from POD#1 to POD#3 was more than minimal amount (0.5 mL/kg/hr) in the both groups. Incidence rate of AKI in the study group was not higher than the control group (Stage I: 1.7% versus 2.9%, p > 0.999; stage II: 0% versus 1.4%, p > 0.999).

CONCLUSION

There was no decrease in incidence of morbidity including POPF following PD with perioperative fluid restriction. Fluid restriction was feasible because it did not reduce urine output and did not increase incidence of AKI.

Lung Ultrasound Assisted Comparison of Volume Effects of Fluid Replacement Regimens in Pediatric Patients Undergoing Penile Hypospadias Repair: A Randomized Controlled Trial

Background

Effective perioperative fluid therapy is a great consideration.

Objectives

Using lung ultrasound (LUS), this study evaluated the preference of the conventional and restrictive fluid replacement regimens for their volume impact in pediatric patients undergoing a relatively long procedure with limited volume loss (hypospadias repair).

Methods

Eighty pediatric patients scheduled for hypospadias repair surgery were enrolled for conventional (CG) or restrictive fluid management groups (RG). The CG obtained Ringer's lactate at the conventional calculated doses, while the RG obtained infusion of Ringer's lactate at a rate of 3 mL/kg/h. B-line numbers in the LUS, recovery score, urine output, blood pressure (BP), heart rate HR, and oxygen saturation (SpO₂) were recorded.

Results

As evidenced by the LUS, RG showed a higher incidence of normal lung morphology with a mean and SD of 1.3 ± 2.2 for B-line numbers, whereas, in CG, they were 3.1 ± 2.2 with a P-value < 0.001. Urine output was 3.2 ± 0.8 and 2.9 ± 0.7 for CG and RG, respectively, with a P-value equal to 0.07. HR, BP, and SpO₂ differences between groups were statistically insignificant. The recovery score was higher in RG (5.8 ± 0.4) than in CG (5.1 ± 0.8) at the first postoperative 20 minutes, with a P-value < 0.001.

Conclusions

In lengthy procedures with limited volume loss, using a moderately restrictive regimen is preferred over the conventional intraoperative fluid regimen considering both respiratory dysfunctions and recovery score.

Male sex, ostomy, infection, and intravenous fluids are associated with increased risk of postoperative ileus in elective colorectal surgery

BACKGROUND

Postoperative ileus is a common and costly complication after elective colorectal surgery. Effects of intravenous fluid administration remain controversial, and the effect of ostomy construction has not been fully evaluated. Various restrictive intravenous fluid protocols may adversely affect renal function. We aimed to investigate the impact of intestinal reconstruction and intravenous fluid on ileus and renal function after colorectal resection under an enhanced recovery protocol.

METHODS

A retrospective study of a prospectively maintained institutional database for a tertiary academic medical center following National Surgical Quality Improvement Program standards was reviewed, analyzing elective colorectal resections performed under enhanced recovery protocol from 2015 to 2018. Postoperative ileus was defined as nasogastric decompression, nil per os >3 days postoperatively, or nasogastric tube insertion. Patients with and without ileus were compared. Intravenous fluid and different anastomoses and ostomies were investigated. Acute kidney injury was a secondary outcome, due to the potential of renal damage with restriction of intravenous fluid volume during and after surgery and controversy in current literature in this matter.

RESULTS

Postoperative ileus occurred in 18.5% of patients (n = 464). Male sex (odds ratio 1.97, 95% confidence interval 1.12-3.52) and postoperative infection (odds ratio 2.13, 95% confidence interval 1.03-4.35) were associated with ileus. Compared to colorectal anastomosis, ileostomy/ileorectal anastomosis had the highest risk of ileus (odds ratio 4.9, 95% confidence interval 2.33-11.3), colostomy second highest (odds ratio 3.3, 95% confidence interval 1.35-8.39), while ileocolic anastomosis did not significantly differ (odds ratio 2.06, 95% confidence interval 0.69-5.85) on multivariate analysis. Each liter of intravenous fluid within the first 72 hours significantly correlated with postoperative ileus (odds ratio 1.41, 95% confidence interval 1.27-1.59). Rates of acute kidney injury did not differ (P = .18).

CONCLUSION

Each additional liter of intravenous fluid given in the first 72 hours increased the risk of postoperative ileus 1.4-fold. There is substantially higher risk of ileus with male sex, infection, ileostomy/ileorectal anastomosis, and colostomy. Judicious use of intravenous fluid, as described in our enhanced recovery protocol, is not detrimental for renal function in the setting of normal baseline.

[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.

State-of-the-art colorectal disease: postoperative ileus

PURPOSE

Postoperative Ileus (POI) remains an important complication for patients after abdominal surgery with an incidence of 10-27% representing an everyday issue for abdominal surgeons. It accounts for patients' discomfort, increased morbidity, prolonged hospital stays, and a high economic burden. This review outlines the current understanding of POI pathophysiology and focuses on preventive treatments that have proven to be effective or at least show promising effects.

METHODS

Pathophysiology and recommendations for POI treatment are summarized on the basis of a selective literature review.

RESULTS

While a lot of therapies have been researched over the past decades, many of them failed to prove successful in meta-analyses. To date, there is no evidence-based treatment once POI has manifested. In the era of enhanced recovery after surgery or fast track regimes, a few approaches show a beneficial effect in preventing POI: multimodal, opioid-sparing analgesia with placement of epidural catheters or transverse abdominis plane block; μ-opioid-receptor antagonists; and goal-directed fluid therapy and in general the use of minimally invasive surgery.

CONCLUSION

The results of different studies are often contradictory, as a concise definition of POI and reliable surrogate endpoints are still absent. These will be needed to advance POI research and provide clinicians with consistent data to improve the treatment strategies.

Management of Acute Kidney Injury Following Major Abdominal Surgery: A Contemporary Review

Acute kidney injury (AKI) is a frequent occurrence following major abdominal surgery and is independently associated with both in-hospital and long-term mortality, as well as with a higher risk of progressing to chronic kidney disease (CKD) and cardiovascular events. Postoperative AKI can account for up to 40% of in-hospital AKI cases. Given the differences in patient characteristics and the pathophysiology of postoperative AKI, it is inappropriate to assume that the management after noncardiac and nonvascular surgery are the same as those after cardiac and vascular surgery. This article provides a comprehensive review on the available evidence on the management of postoperative AKI in the setting of major abdominal surgery.

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).

Perioperative Fluid Therapy for Major Surgery

A moderately liberal IV fluid regimen, using a balanced crystalloid, and consideration of the use of an advanced hemodynamic monitor in a setting of an enhanced recovery pathway are recommended for major surgery.

Supplemental Digital Content is available in the text.

Does goal-directed haemodynamic and fluid therapy improve peri-operative outcomes?: A systematic review and meta-analysis

BACKGROUND

Much uncertainty exists as to whether peri-operative goal-directed therapy is of benefit.

OBJECTIVES

To discover if peri-operative goal-directed therapy decreases mortality and morbidity in adult surgical patients.

DESIGN

An updated systematic review and random effects meta-analysis of randomised controlled trials.

DATA SOURCES

Medline, Embase and the Cochrane Library were searched up to 31 December 2016.

ELIGIBILITY CRITERIA

Randomised controlled trials enrolling adult surgical patients allocated to receive goal-directed therapy or standard care were eligible for inclusion. Trauma patients and parturients were excluded. Goal-directed therapy was defined as fluid and/or vasopressor therapy titrated to haemodynamic goals [e.g. cardiac output (CO)]. Outcomes included mortality, morbidity and hospital length of stay. Risk of bias was assessed using Cochrane methodology.

RESULTS

Ninety-five randomised trials (11 659 patients) were included. Only four studies were at low risk of bias. Modern goal-directed therapy reduced mortality compared with standard care [odds ratio (OR) 0.66; 95% confidence interval (CI) 0.50 to 0.87; number needed to treat = 59; N = 52; I = 0.0%]. In subgroup analysis, there was no mortality benefit for fluid-only goal-directed therapy, cardiac surgery patients or nonelective surgery. Contemporary goal-directed therapy also reduced pneumonia (OR 0.69; 95% CI, 0.51 to 0. 92; number needed to treat = 38), acute kidney injury (OR 0. 73; 95% CI, 0.58 to 0.92; number needed to treat = 29), wound infection (OR 0.48; 95% CI, 0.37 to 0.63; number needed to treat = 19) and hospital length of stay (days) (-0.90; 95% CI, -1.32 to -0.48; I = 81. 2%). No important differences in outcomes were found for the pulmonary artery catheter studies, after accounting for advances in the standard of care.

CONCLUSION

Peri-operative modern goal-directed therapy reduces morbidity and mortality. Importantly, the quality of evidence was low to very low (e.g. Grading of Recommendations, Assessment, Development and Evaluation scoring), and there was much clinical heterogeneity among the goal-directed therapy devices and protocols. Additional well designed and adequately powered trials on peri-operative goal-directed therapy are necessary.

Restricting Intraoperative Fluid Volume Allows Earlier Return of Bowel Function After Colon and Rectal Surgery

BACKGROUND

Return of bowel function (ROBF) after abdominal surgery is an important determinant of patient outcomes. The role of intraoperative fluids (IOFs) in colon surgery remains unclear. The aim of this study was to assess the impact of IOF on ROBF in patients undergoing colon surgery. We hypothesized that minimizing IOFs allows earlier ROBF.

METHODS

A 2-year (2016-2017) retrospective analysis of all patients undergoing elective colon resection was performed at our tertiary hospital using a protocol limiting IOF and postoperative narcotics. Patients were divided into two groups: preprotocol (2016) and postprotocol (PoP) (2017). Patients were matched using propensity score matching for age, gender, comorbidities, Anesthesiology Severity Score, indication for procedure, and procedure type. The outcome measured was ROBF. Secondary outcome measures were complication rates and hospital length of stay.

RESULTS

A total of 360 patients were analyzed. After propensity matching, 90 patients (preprotocol: 45; PoP: 45) were included. The mean age was 62.2 ± 14.8 y, 43.3% male, and 44.4% of procedures were performed laparoscopically. There was no difference in demographics and comorbidities between groups. PoP patients received lower IOF (P = 0.036, 2016: 1198.8 ± 1096.5 mL, 2017: 2176.7 ± 1458.3 mL) and lower postoperative narcotics (P = 0.042). PoP patients had earlier ROBF 2[2-4], 4[3-5] (odds ratio: 1.18 [1.05-1.52], P = 0.04), shorter length of stay 3[2-5] d versus 5[4-7] (odds ratio: 1.11 [1.09-1.89], P = 0.043), and trended toward lower complication rates (P = 0.09).

CONCLUSIONS

IOF volume independently impacts ROBF after colon surgery. Restricting IOF allows for earlier bowel function and shorter hospital stay. Further studies defining optimum fluid management impacting ROBF may help optimize patient care.

Clinical guidelines for perioperative hemodynamic management of non cardiac surgical adult patients

Perioperative hemodynamic management, through monitoring and intervention on physiological parameters to improve cardiac output and oxygen delivery (goal-directed therapy, GDT), may improve outcome. However, an Italian survey has revealed that hemodynamic protocols are applied by only 29.1% of anesthesiologists. Aim of this paper is to provide clinical guidelines for a rationale use of perioperative hemodynamic management in non cardiac surgical adult patients, oriented for Italy and updated with most recent studies. Guidelines were elaborated according to NICE (National Institute for Health and Care Excellence) and GRADE system (Grading of Recommendations of Assessment Development and Evaluations). Key questions were formulated according to PICO system (Population, Intervention, Comparators, Outcome). Guidelines and systematic reviews were identified on main research databases and strategy was updated to June 2018. There is not enough good quality evidence to support the adoption of a GDT protocol in order to reduce mortality, although it may be useful in high risk patients. Perioperative GDT protocol to guide fluid therapy is recommended to reduce morbidity. Continuous monitoring of arterial pressure may help to identify short periods of hemodynamic instability and hypotension. Fluid strategy should aim to a near zero balance in normovolemic patients at the beginning of surgery, and a slight positive fluid balance may be allowed to protect renal function. Drugs such as inotropes, vasocostrictors, and vasodilatator should be used only when fluids alone are not sufficient to optimize hemodynamics. Perioperative GDT protocols are associated with a reduction in costs, although no economic study has been performed in Italy.

Restrictive Versus Liberal Fluid Regimens in Patients Undergoing Pancreaticoduodenectomy: a Systematic Review and Meta-Analysis

BACKGROUND

Pancreaticoduodenectomy is associated with significant morbidity and mortality which may be influenced by perioperative fluid management. It remains unclear whether liberal and restrictive fluid regimens impact mortality and morbidity in patients undergoing pancreaticoduodenectomy.

METHODS

Medline, EMBASE, Cochrane Library and clinicaltrials.gov were searched for studies comparing restrictive and liberal perioperative fluids in patients undergoing pancreaticoduodenectomy. Both prospective and retrospective studies in those undergoing pancreaticoduodenectomy were eligible for inclusion where the patient outcomes were stratified to restrictive and liberal perioperative fluid management regimens, with mortality as the primary outcome. Following study identification, a systematic review and meta-analysis with trial sequential analysis was completed.

RESULTS

Thirteen studies including five prospective trials and eight retrospective analyses totalling 3062 patients were included. Restrictive fluid regimens were associated with a significant reduction in mortality compared to liberal fluid regimens for the overall cohort (odds ratio 0.54; 95% CI 0.31-0.94, p = 0.03). There were no significant differences in complication profile. Subgroup analysis revealed this result was contributed to significantly by retrospective studies. The results of the trial sequential analysis suggest this mortality benefit may be due to a type I statistical error and that further patient numbers are required for definitive conclusions.

CONCLUSIONS

Restrictive fluid regimens are associated with a reduction in mortality following pancreaticoduodenectomy. The clinical relevance of this finding needs to be interpreted pragmatically given the lack of association with significant causes of morbidity and in considering the results of the recently published RELIEF study.

PERioperative Fluid Management in Elective ColecTomy (PERFECT)-a national prospective cohort study

BACKGROUND

There is contradictory evidence regarding the merits of restricted versus liberal perioperative intravenous (IV) fluid administration in bowel surgery. This study sought to audit perioperative fluid management in elective colectomy in Ireland and to analyse the impact of such on operative outcomes.

METHODS

A national surgical trainee collaborative audit of perioperative fluid management was performed. Data from each site was collected prospectively over a selected 3-week period within a pre-defined 2-month block. Collected variables included demographics, type of operation/anaesthethic, volume/type of fluid administration pre-, intra- and post-operatively, 30-day morbidity and mortality. Primary outcome was fluid balance 24-h post-operatively with further analysis to identify the impact of this on 30-day morbidity. ROC curves were generated to identify the critical volume at which fluid balance was associated with 30-day morbidity.

RESULTS

Ninety-four patients were enrolled from 17 hospitals. Mean age was 64 years. A total of 48.9% (N = 46) were managed by ERAS and 51.1% (N = 48) received bowel preparation. Almost 70% of cases (N = 63) were completed by minimally invasive techniques. Significant 30-day morbidity requiring hospital readmission was low [6.4% (n = 6)]. Median fluid balance at 24 h was + 715 ml (IQR 165-1486 ml). On multivariate analysis, high BMI (p = 0.02), indication for surgery (p = 0.02) and critical care admission (p = 0.008) were significantly predictive of 30-day morbidity. Twenty-four hour fluid balance >+ 665 ml was associated with increased risk of 30-day morbidity on univariate but not multivariate analysis, implying association but not causation.

CONCLUSION

Overall, perioperative fluid management was within an acceptable range with minimal impact on 30-day morbidity following elective colorectal surgery.

Optimal crystalloid volume ratio for blood replacement for maintaining hemodynamic stability and lung function: an experimental randomized controlled study

BACKGROUND

Crystalloids are first line in fluid resuscitation therapy, however there is a lack of evidence-based recommendations on the volume to be administered. Therefore, we aimed at comparing the systemic hemodynamic and respiratory effects of volume replacement therapy with a 1:1 ratio to the historical 1:3 ratio.

METHODS

Anesthetized, ventilated rats randomly included in 3 groups: blood withdrawal and replacement with crystalloid in 1:1 ratio (Group 1, n = 11), traditional 1:3 ratio (Group 3, n = 12) and a control group with no interventions (Group C, n = 9). Arterial blood of 5% of the total blood volume was withdrawn 7 times, and replaced stepwise with different volume rations of Ringer's acetate, according to group assignments. Airway resistance (Raw), respiratory tissue damping (G) and tissue elastance (H), mean arterial pressure (MAP) and heart rate (HR) were assessed following each step of fluid replacement with a crystalloid (CR1-CR6). Lung edema index was measured from histological samples.

RESULTS

Raw decreased in Groups 1 and 3 following CR3 (p < 0.02) without differences between the groups. H elevated in all groups (p < 0.02), with significantly higher changes in Group 3 compared to Groups C and 1 (both p = 0.03). No differences in MAP or HR were present between Groups 1 and 3. Lung edema was noted in Group 3 (p < 0.05).

CONCLUSIONS

Fluid resuscitation therapy by administering a 1:1 blood replacement ratio revealed adequate compensation capacity and physiological homeostasis similar with no lung stiffening and pulmonary edema. Therefore, considering this ratio promotes the restrictive fluid administration in the presence of continuous and occult bleeding.

Systematic Review and Meta-analysis of Restrictive Perioperative Fluid Management in Pancreaticoduodenectomy

BACKGROUND

There is significant interest and controversy surrounding the effect of restrictive fluid management on outcomes in major gastrointestinal surgery. This has been most studied in colorectal surgery, although the literature relating to pancreaticoduodenectomy (PD) patients is growing. The aim of this paper was to generate a comprehensive review of the available evidence for restrictive perioperative fluid management strategies and outcomes in PD.

METHODS

MEDLINE/PubMed, Embase, and the Cochrane Library were searched from inception to April 2017. A review protocol was utilized and registered with PROSPERO. Primary citations that evaluated perioperative fluid management in PD, including those as part of a clinical pathway, were considered. The primary outcome was postoperative pancreatic fistula (POPF). Secondary outcomes included delayed gastric emptying (DGE), complication rate, length of stay (LOS), mortality, and readmission.

RESULTS

A total of six studies involving 846 patients were included (2009-2015), of which four were RCTs. Pooled analysis of RCTs and high-quality observational studies found no effect of restrictive intraoperative fluid management on POPF, DGE, complication rate, LOS, mortality, and readmission. Only one study assessed postoperative fluid management exclusively and found prolonged LOS in patients in the restricted fluid group.

CONCLUSION

Based on results of RCTs and high-quality observational studies, intraoperative fluid restriction in PD has not been shown to significantly affect postoperative outcomes. There are too few studies assessing postoperative fluid management to draw conclusions at this time.

Effects of perioperative fluid management on postoperative outcomes in liver transplantation: a systematic review protocol

BACKGROUND

Liver transplant recipients suffer many complications, but few intraoperative interventions supported by high-quality evidence have been found effective to reduce their incidence or severity. Fluid balance has been proposed as an important aspect of perioperative care in high-risk recipients. We will conduct a systematic review aimed at evaluating the effects of restrictive perioperative fluid management strategies compared to liberal ones on clinically significant postoperative outcomes.

METHODS

We will search through major databases (CINAHL Complete, EMB Reviews, EMBASE, MEDLINE, PubMed, and the gray literature (CADTH, Clinical Trials, National Guideline Clearing House, NICE, MedNar, Google Scholar and Open Grey)), from inception up to a date close to the review submission for publication, for eligible studies. Randomized controlled trials and comparative non-randomized studies (prospective or retrospective) comparing two fluid management strategies (or two outcomes with available data on fluid volume received for observational studies) on adult liver recipients will be included. Eligible studies will have to report at least one postoperative complication or mortality. Our primary outcome will be acute renal failure and our secondary exploratory outcomes will be all other postoperative complications and mortality. Study selection and data abstraction using an electronic standardized form will be performed by three authors. Risk of bias will be evaluated and data will be pooled if limited clinical diversity is observed.

DISCUSSION

Human organs available for transplantation are scarce resources. Strategies to improve recipients' survival are needed. We hypothesize that restrictive fluid management strategies will be associated with better postoperative outcomes than liberal fluid management strategies. This systematic review will improve our understanding of the available evidence and help us better inform future clinical trials.

SYSTEMATIC REVIEW REGISTRATION

This systematic review protocol is registered in PROSPERO ( CRD42017054970 ).

Restrictive versus Liberal Fluid Therapy for Major Abdominal Surgery

BACKGROUND

Guidelines to promote the early recovery of patients undergoing major surgery recommend a restrictive intravenous-fluid strategy for abdominal surgery. However, the supporting evidence is limited, and there is concern about impaired organ perfusion.

METHODS

In a pragmatic, international trial, we randomly assigned 3000 patients who had an increased risk of complications while undergoing major abdominal surgery to receive a restrictive or liberal intravenous-fluid regimen during and up to 24 hours after surgery. The primary outcome was disability-free survival at 1 year. Key secondary outcomes were acute kidney injury at 30 days, renal-replacement therapy at 90 days, and a composite of septic complications, surgical-site infection, or death.

RESULTS

During and up to 24 hours after surgery, 1490 patients in the restrictive fluid group had a median intravenous-fluid intake of 3.7 liters (interquartile range, 2.9 to 4.9), as compared with 6.1 liters (interquartile range, 5.0 to 7.4) in 1493 patients in the liberal fluid group (P<0.001). The rate of disability-free survival at 1 year was 81.9% in the restrictive fluid group and 82.3% in the liberal fluid group (hazard ratio for death or disability, 1.05; 95% confidence interval, 0.88 to 1.24; P=0.61). The rate of acute kidney injury was 8.6% in the restrictive fluid group and 5.0% in the liberal fluid group (P<0.001). The rate of septic complications or death was 21.8% in the restrictive fluid group and 19.8% in the liberal fluid group (P=0.19); rates of surgical-site infection (16.5% vs. 13.6%, P=0.02) and renal-replacement therapy (0.9% vs. 0.3%, P=0.048) were higher in the restrictive fluid group, but the between-group difference was not significant after adjustment for multiple testing.

CONCLUSIONS

Among patients at increased risk for complications during major abdominal surgery, a restrictive fluid regimen was not associated with a higher rate of disability-free survival than a liberal fluid regimen and was associated with a higher rate of acute kidney injury. (Funded by the Australian National Health and Medical Research Council and others; RELIEF ClinicalTrials.gov number, NCT01424150 .).

Hemodynamic effects of different types of pneumatic compression of the lower extremities during anesthesia induction: a prospective randomized controlled trial

Background

The current study evaluated the hemodynamic effects of different types of pneumatic compressions of the lower extremities during anesthesia induction. In addition, the hemodynamic effects were compared between patients older than 65 age years and those aged 65 years or younger.

Methods

One hundred and eighty patients (90: > 65 years and 90: ≤ 65 years) were enrolled. Each age group of patients was randomly assigned to one of three groups; Group 1 (no compression), Group 2 (sequential pneumatic compression), and Group 3 (sustained pneumatic compression without decompression). Invasive blood pressure, cardiac index (CI), and stroke volume variation (SVV) were measured.

Results

In patients aged ≤ 65 years, mean arterial pressure (MAP) and CI were significantly higher and SVV was lower in Group 3 compared to Group 1 before tracheal intubation, but there were no differences between Groups 1 and 2. However, there were no differences in MAP, CI, and SVV among the three groups in patients aged > 65 years. The number of patients who showed a MAP < 60 mmHg was less in Group 3 than Group 1 in patients aged ≤ 65 years, but not in patients aged > 65 years.

Conclusions

Sustained pneumatic compression of the lower extremities has more hemodynamic stabilizing effects compared to sequential compression during anesthesia induction in patients aged 65 years or younger. However, no difference between methods of compression was observed in patients older than 65 years.

Cumulative positive fluid balance is a risk factor for acute kidney injury and requirement for renal replacement therapy after liver transplantation

AIM

To analyze whether fluid overload is an independent risk factor of adverse outcomes after liver transplantation (LT).

METHODS

One hundred and twenty-one patients submitted to LT were retrospectively evaluated. Data regarding perioperative and postoperative variables previously associated with adverse outcomes after LT were reviewed. Cumulative fluid balance (FB) in the first 12 h and 4 d after surgery were compared with major adverse outcomes after LT.

RESULTS

Most of the patients were submitted to a liberal approach of fluid administration with a mean cumulative FB over 5 L and 10 L, respectively, in the first 12 h and 4 d after LT. Cumulative FB in 4 d was independently associated with occurrence of both AKI and requirement for renal replacement therapy (RRT) (OR = 2.3; 95%CI: 1.37-3.86, P = 0.02 and OR = 2.89; 95%CI: 1.52-5.49, P = 0.001 respectively). Other variables on multivariate analysis associated with AKI and RRT were, respectively, male sex and Acute Physiology and Chronic Health Disease Classification System (APACHE II) levels and sepsis or septic shock. Mortality was shown to be independently related to AST and APACHE II levels (OR = 2.35; 95%CI: 1.1-5.05, P = 0.02 and 2.63; 95%CI: 1.0-6.87, P = 0.04 respectively), probably reflecting the degree of graft dysfunction and severity of early postoperative course of LT. No effect of FB on mortality after LT was disclosed.

CONCLUSION

Cumulative positive FB over 4 d after LT is independently associated with the development of AKI and the requirement of RRT. Survival was not independently related to FB, but to surrogate markers of graft dysfunction and severity of postoperative course of LT.

Contemporary Approaches to Perioperative IV Fluid Therapy

BACKGROUND

Intravenous fluid therapy is required for most surgical patients, but inappropriate regimens are commonly prescribed. The aim of this narrative review was to provide evidence-based guidance on appropriate perioperative fluid management.

METHOD

We did a systematic literature search of the literature to identify relevant studies and meta-analyses to develop recommendations.

RESULTS

Of 275 retrieved articles, we identified 25 articles to inform this review. "Normal" saline (0.9% sodium chloride) is not physiological and can result in sodium overload and hyperchloremic acidosis. Starch colloid solutions are not recommended in surgical patients at-risk of sepsis or renal failure. Most surgical patients can have clear fluids and/or administration of carbohydrate-rich drinks up to 2 h before surgery. An intraoperative goal-directed fluid strategy may reduce postoperative complications and reduce hospital length of stay. Regular postoperative assessment of the patient's fluid status and requirements should include looking for physical signs of dehydration or hypovolemia, or fluid overload. Both hypovolemia and salt and water overload lead to adverse events, complications and prolonged hospital stay. Urine output can be an unreliable indicator of hydration status in the postoperative surgical patient. Excess fluid administration has been linked to acute kidney injury, gastrointestinal dysfunction, and cardiac and pulmonary complications.

CONCLUSION

There is good evidence supporting the avoidance of unnecessary fasting and the value of an individualized perioperative IV fluid regimen, with transition to oral fluids as soon as possible, to help patients recover from major surgery.

Restrictive and liberal fluid administration in major abdominal surgery

Objectives:

To determine whether perioperative fluid restrictive administration can reduce specific postoperative complications in adults undergoing major abdominal surgery.

Methods:

We searched the MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials, Google scholar, and article reference lists (up to December 2015) for studies that assessed fluid therapy and morbidity or mortality in patients undergoing major abdominal surgeries. The quality of the trials was assessed using the Jadad scoring system, and a meta-analysis of the included randomized, controlled trials was conducted using Review Manager software, version 5.2.

Results:

Ten studies with a total of 1160 patients undergoing major abdominal surgeries were included. We found that perioperative restrictive fluid therapy could reduce the risk of postoperative infectious complications (odds ratio [OR]=0.54, 95% confidence interval [CI]:0.39-0.74, p=0.0001, I²=37%), pulmonary complications (OR=0.49, 95% CI: 0.26-0.93, p=0.03, I²=50%), and cardiac complications (OR=0.45, 95% CI: 0.29-0.69, p=0.0003, I²=48%), but had no effect on the risk of gastrointestinal complications (OR=0.87, 95% CI: 0.51-1.46, p=0.59, I²=0%), renal complications (OR=0.76, 95% CI: 0.43-1.34, p=0.35, I²=0%), and postoperative mortality (OR=0.62, 95% CI: 0.25-1.50, p=0.29, I²=0%).

Conclusion:

Perioperative restrictive fluid administration was superior to liberal fluid administration in reducing the infectious, pulmonary and cardiac complications after major abdominal surgeries.

Restrictive versus liberal fluid therapy in major abdominal surgery (RELIEF): rationale and design for a multicentre randomised trial

INTRODUCTION

The optimal intravenous fluid regimen for patients undergoing major abdominal surgery is unclear. However, results from many small studies suggest a restrictive regimen may lead to better outcomes. A large, definitive clinical trial evaluating perioperative fluid replacement in major abdominal surgery, therefore, is required.

METHODS/ANALYSIS

We designed a pragmatic, multicentre, randomised, controlled trial (the RELIEF trial). A total of 3000 patients were enrolled in this study and randomly allocated to a restrictive or liberal fluid regimen in a 1:1 ratio, stratified by centre and planned critical care admission. The expected fluid volumes in the first 24 hour from the start of surgery in restrictive and liberal groups were ≤3.0 L and ≥5.4 L, respectively. Patient enrolment is complete, and follow-up for the primary end point is ongoing. The primary outcome is disability-free survival at 1 year after surgery, with disability defined as a persistent (at least 6 months) reduction in functional status using the 12-item version of the World Health Organisation Disability Assessment Schedule.

ETHICS/DISSEMINATION

The RELIEF trial has been approved by the responsible ethics committees of all participating sites. Participant recruitment began in March 2013 and was completed in August 2016, and 1-year follow-up will conclude in August 2017. Publication of the results of the RELIEF trial is anticipated in early 2018.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov identifier NCT01424150.

Liberal perioperative fluid administration is an independent risk factor for morbidity and is associated with longer hospital stay after rectal cancer surgery

INTRODUCTION Recent studies have advocated the use of perioperative fluid restriction in patients undergoing major abdominal surgery as part of an enhanced recovery protocol. Series reported to date include a heterogenous group of high- and low-risk procedures but few studies have focused on rectal cancer surgery alone. The aim of this study was to assess the effects of perioperative fluid volumes on outcomes in patients undergoing elective rectal cancer resection. METHODS A prospectively maintained database of patients with rectal cancer who underwent elective surgery over a 2-year period was reviewed. Total volume of fluid received intraoperatively was calculated, as well as blood products required in the perioperative period. The primary outcome was postoperative morbidity (Clavien-Dindo grade I-IV) and the secondary outcomes were length of stay and major morbidity (Clavien-Dindo grade III-IV). RESULTS Over a 2-year period (2012-2013), 120 patients underwent elective surgery with curative intent for rectal cancer. Median total intraoperative fluid volume received was 3680ml (range 1200-9670ml); 65/120 (54.1%) had any complications, with 20/120 (16.6%) classified as major (Clavien-Dindo grade III-IV). Intraoperative volume >3500ml was an independent risk factor for the development of postoperative all-cause morbidity (P=0.02) and was associated with major morbidity (P=0.09). Intraoperative fluid volumes also correlated with length of hospital stay (Pearson's correlation coefficient 0.33; P<0.01). CONCLUSIONS Intraoperative fluid infusion volumes in excess of 3500ml are associated with increased morbidity and length of stay in patients undergoing elective surgery for rectal cancer.

Acute kidney injury in the perioperative period and in intensive care units (excluding renal replacement therapies)

Acute kidney injury (AKI) is a syndrome that has progressed a great deal over the last 20 years. The decrease in urine output and the increase in classical renal biomarkers, such as blood urea nitrogen and serum creatinine, have largely been used as surrogate markers for decreased glomerular filtration rate (GFR), which defines AKI. However, using such markers of GFR as criteria for diagnosing AKI has several limits including the difficult diagnosis of non-organic AKI, also called "functional renal insufficiency" or "pre-renal insufficiency". This situation is characterized by an oliguria and an increase in creatininemia as a consequence of a reduction in renal blood flow related to systemic haemodynamic abnormalities. In this situation, "renal insufficiency" seems rather inappropriate as kidney function is not impaired. On the contrary, the kidney delivers an appropriate response aiming to recover optimal systemic physiological haemodynamic conditions. Considering the kidney as insufficient is erroneous because this suggests that it does not work correctly, whereas the opposite is occurring, because the kidney is healthy even in a threatening situation. With current definitions of AKI, normalization of volaemia is needed before defining AKI in order to avoid this pitfall.

Best practice for perioperative management of patients with cytoreductive surgery and HIPEC

Due to the significantly improved outcome and quality of life of patients with different tumor entities after cytoreductive surgery (CRS) and HIPEC, there is an increasing number of centers performing CRS and HIPEC procedures. As this procedure is technically challenging with potential high morbidity and mortality, respectively, institutional experience also in the anesthetic and intensive care departments is essential for optimal treatment and prevention of adverse events. Clinical pathways have to be developed to achieve also good results in more comorbid patients with border line indications and extensive surgical procedures. The anesthesiologist has deal with relevant fluid, blood and protein losses, increased intraabdominal pressure, systemic hypo-/hyperthermia, and increased metabolic rate in patients undergoing cytoreductive surgery with HIPEC. It is of utmost importance to maintain or restore an adequate volume by aggressive substitution of intravenous fluids, which counteracts the increased fluid loss and venous capacitance during this procedure. Supplementary thoracic epidural analgesia, non-invasive ventilation, and physiotherapy are recommended to guarantee adequate pain therapy and postoperative extubation as well as fast-track concepts. Advanced hemodynamic monitoring is essential to help the anesthesiologist picking up information about the real-time fluid status of the patient. Preoperative preconditioning is mandatory in patients scheduled for HIPEC surgery and will result in improved outcome. Postoperatively, volume status optimization, early nutritional support, sufficient anticoagulation, and point of care coagulation management are essential. This is an extensive update on all relevant topics for anesthetists and intensivists dealing with CRS and HIPEC.

Impact of Initial Central Venous Pressure on Outcomes of Conservative Versus Liberal Fluid Management in Acute Respiratory Distress Syndrome

OBJECTIVES

In acute respiratory distress syndrome, conservative fluid management increases ventilator-free days without affecting mortality. Response to fluid management may differ based on patients' initial central venous pressure. We hypothesized that initial central venous pressure would modify the effect of fluid management on outcomes.

DESIGN

Retrospective analysis of the Fluid and Catheter Treatment Trial, a multicenter randomized trial comparing conservative with liberal fluid management in acute respiratory distress syndrome. We examined the relationship between initial central venous pressure, fluid strategy, and 60-day mortality in univariate and multivariable analysis.

SETTING

Twenty acute care hospitals.

PATIENTS

Nine hundred thirty-four ventilated acute respiratory distress syndrome patients with a central venous pressure available at enrollment, 609 without baseline shock (for whom fluid balance was managed by the study protocol).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Among patients without baseline shock, those with initial central venous pressure greater than 8 mm Hg experienced similar mortality with conservative and liberal fluid management (18% vs 18%; p = 0.928), whereas those with central venous pressure of 8 mm Hg or less experienced lower mortality with a conservative strategy (17% vs 36%; p = 0.005). Multivariable analysis demonstrated an interaction between initial central venous pressure and the effect of fluid strategy on mortality (p = 0.031). At higher initial central venous pressures, the difference in treatment between arms was predominantly furosemide administration, which was not associated with mortality (p = 0.122). At lower initial central venous pressures, the difference between arms was predominantly fluid administration, with additional fluid associated with increased mortality (p = 0.013).

CONCLUSIONS

Conservative fluid management decreases mortality for acute respiratory distress syndrome patients with a low initial central venous pressure. In this population, the administration of IV fluids seems to increase mortality.

Liberal or restrictive fluid management during elective surgery: a systematic review and meta-analysis

This article reviews if a restrictive fluid management policy reduces the complication rate if compared to liberal fluid management policy during elective surgery. The PubMed database was explored by 2 independent researchers. We used the following search terms: "Blood transfusion (MESH); transfusion need; fluid therapy (MESH); permissive hypotension; fluid management; resuscitation; restrictive fluid management; liberal fluid management; elective surgery; damage control resuscitation; surgical procedures, operative (MESH); wounds (MESH); injuries (MESH); surgery; trauma patients." A secondary search in the Medline, EMBASE, Web of Science, and Cochrane library revealed no additional results. We selected randomized controlled trials performed during elective surgeries. Patients were randomly assigned to a restrictive fluid management policy or to a liberal fluid management policy during elective surgery. The patient characteristics and the type of surgery varied. All but 3 studies reported American Society of Anaesthesiologists groups 1 to 3 as the inclusion criterion. The primary outcome of interest is total number of patients with a complication and the complication rate. Secondary outcome measures are infection rate, transfusion need, postoperative rebleeding, hospital stay, and renal function. In total, 1397 patients were analyzed (693 restrictive protocol, 704 liberal protocol). Meta-analysis showed that in the restrictive group as compared with the liberal group, fewer patients experienced a complication (relative risk [RR], 0.65; 95% confidence interval [CI], 0.55-0.78). The total complication rate (RR, 0.57; 95% CI, 0.52-0.64), risk of infection (RR, 0.62; 95% CI, 0.48-0.79), and transfusion rate (RR, 0.81; 95% CI, 0.66-0.99) were also lower. The postoperative rebleeding did not differ in both groups: RR, 0.76 (95% CI, 0.28-2.06). We conclude that compared with a liberal fluid policy, a restrictive fluid policy in elective surgery results in a 35% reduction in patients with a complication and should be advised as the preferred fluid management policy.

Efficacy of prothrombin complex concentrates for the emergency reversal of dabigatran-induced anticoagulation

Dabigatran is effective in decreasing the risk of ischaemic stroke in patients with atrial fibrillation. However, like all anticoagulants, it is associated with a risk of bleeding. In cases of trauma or emergency surgery, emergency reversal of dabigatran-induced anticoagulation may be required. A specific reversal agent for dabigatran, idarucizumab, has been approved by the US Food and Drug Administration. Alternative reversal agents are available, such as prothrombin complex concentrates (PCCs) and activated PCCs (aPCCs). In this review we evaluate the role of PCCs and aPCCs in the reversal of dabigatran anticoagulation and consider which tests are appropriate for monitoring coagulation in this setting. Pre-clinical studies, small clinical studies and case reports indicate that PCCs and aPCCs may be able to reverse dabigatran-induced anticoagulation in a dose-dependent manner. However, dosing based on coagulation parameters can be difficult because available assays may not provide adequate sensitivity and specificity for measuring anticoagulation induced by dabigatran or the countering effects of PCCs/aPCCs. In addition, PCCs or aPCCs can potentially provoke thromboembolic complications. Despite these limitations and the fact that PCCs and aPCCs are not yet licensed for dabigatran reversal, their use appears to be warranted in patients with life-threatening haemorrhage if idarucizumab is not available.

Intraoperative Fluid Restriction in Pancreatic Surgery: A Double Blinded Randomised Controlled Trial

Background

Perioperative fluid restriction in a variety of operations has shown improvement of: complications, recovery of gastrointestinal function and length of stay (LOS). We investigated effects of crystalloid fluid restriction in pancreatic surgery. Our hypothesis: enhanced recovery of gastrointestinal function.

Methods

In this double-blinded randomized trial, patients scheduled to undergo pancreatoduodenectomy (PD) were randomized: standard (S:10ml/kg/hr) or restricted (R:5ml/kg/hr) fluid protocols. Primary endpoint: gastric emptying scintigraphically assessed on postoperative day 7.

Results

In 66 randomized patients, complications and 6-year survival were analyzed. 54 patients were analyzed in intention to treat: 24 S-group and 30 R-group. 32 patients actually underwent a PD and 16 patients had a palliative gastrojejunostomy bypass operation in the full protocol analysis. The median gastric emptying time (T½) was 104 minutes (S-group, 95% confidence interval: 74–369) versus 159 minutes (R-group, 95% confidence interval: 61–204) (P = 0.893, NS). Delayed gastric emptying occurred in 10 patients in the S-group and in 13 patients in the R-group (45% and 50%, P = 0.779, NS). The primary outcome parameter, gastric emptying time, did not show a statistically significant difference between groups.

Conclusion

A fluid regimen of 10ml/kg/hr or 5ml/kg/hr during pancreatic surgery did not lead to statistically significant differences in gastric emptying. A larger study would be needed to draw definite conclusions about fluid restriction in pancreatic surgery.

Trial registration

ISRCTN62621488

Fluid accumulation threshold measured by acute body weight change after admission in general surgical intensive care units: how much should be concerning?

Background

The objective of this study (ClinicalTrials.gov: NCT01351506) was to identify the threshold level of fluid accumulation measured by acute body weight (BW) change during the first week in a general surgical intensive care unit (ICU), which is associated with ICU mortality and other adverse outcomes.

Methods

Four hundred sixty-five patients were prospectively followed for a 28-day period. The maximum BW change threshold during the first week was evaluated by the maximum percentage change in BW from the ICU admission weight (Max%ΔBW). Daily screening of adverse events in the ICU were recorded. The cutoff point of Max%ΔBW on ICU mortality was defined by considering the area under the receiver operating characteristic (ROC) curve, intersection of the sensitivity and specificity, and the Youden Index. Univariable and multivariable regression analyses were used to demonstrate the associations. Statistical significance was defined as P<0.05.

Results

The appropriate cutoff value of Max%ΔBW threshold was 5%. Regarding the multivariable regression model, in overall patients, the occurrence of the following adverse events (expressed as adjusted odds ratio [95% confidence interval]) were significantly associated with a Max%ΔBW of >5%: ICU mortality (2.38 [1.25–4.54]) (P=0.008), ICU mortality in patients without renal replacement therapy (RRT) (2.47 [1.21–5.06]) (P=0.013), reintubation within 72 hours (2.51 [1.04–6.00]) (P=0.039), RRT requirement (2.67 [1.13–6.33]) (P=0.026), and delirium (1.97 [1.08–3.57]) (P=0.025). Regarding the postoperative subgroup, a Max%ΔBW value of more than 5% was significantly associated with: ICU mortality (3.87 [1.38–10.85]) (P=0.010), ICU mortality in patients without RRT (6.32 [1.85–21.64]) (P=0.003), reintubation within 72 hours (4.44 [1.30–15.16]) (P=0.017), and vasopressor requirement (2.04 [1.04–4.01]) (P=0.037).

Conclusion

Fluid accumulation, measured as acute BW change of more than the threshold of 5% during the first week of ICU admission, is associated with adverse outcomes of higher ICU mortality, especially in the patients without RRT, with reintubation within 72 hours, with RRT requirement, with vasopressor requirement, and with delirium. Some of these effects were higher in postoperative patients. This threshold value might be an indicator for caution during fluid management in surgical ICU.

Assessment of the time-dependent need for stay in a high dependency unit (HDU) after major surgery by using data from an anesthesia information management system

Admittance to a high dependency unit (HDU) is expensive. Patients who receive surgical treatment with 'low anterior resection of the rectum' (LAR) or 'abdominoperineal resection of the rectum' (APR) at our hospital are routinely treated in an HDU the first 16-24 h of the postoperative (PO) period. The aim of this study was to describe the extent of HDU-specific interventions given. We included patients treated with LAR or APR at the St. Olav University Hospital (Trondheim, Norway) over a 1-year period. Physiologic data and HDU-interventions recorded during the PO-period were obtained from the anesthesia information management system (AIMS). HDU-specific interventions were defined as the need for respiratory support, fluid replacement therapy >500 ml/h, vasoactive medications, or a need for high dose opioids (morphine >7.5 mg/h i.v.). Sixty-two patients were included. Most patients needed HDU-specific interventions during the first 6 h of the PO period. After this, one-third of the patients needed one or more of the HDU-specific interventions for shorter periods of time. Another one-third of the patients had a need for HDU-specific therapies for more than ten consecutive hours, primarily an infusion of nor-epinephrine. Most patients treated with LAR or APR was in need of an HDU-specific intervention during the first 6 h of the PO-period, with a marked decline after this time period. The applied methodology, using an AIMS, demonstrates that there is great variability in individual patients' postoperative needs after major surgery, and that these needs are dynamic in their nature.

Impact of early haemodynamic goal-directed therapy in patients undergoing emergency surgery: an open prospective, randomised trial

Haemodynamic goal-directed therapies (GDT) may improve outcome following elective major surgery. So far, few data exist regarding haemodynamic optimization during emergency surgery. In this randomized, controlled trial, 50 surgical patients with hypovolemic or septic conditions were enrolled and we compared two algorithms of GDTs based either on conventional parameters and pressure pulse variation (control group) or on cardiac index, global end-diastolic volume index and stroke volume variation as derived from the PiCCO monitoring system (optimized group). Postoperative outcome was estimated by a composite index including major complications and by the Sequential Organ Failure Assessment (SOFA) Score within the first 3 days after surgery (POD1, POD2 and POD3). Data from 43 patients were analyzed (control group, N = 23; optimized group, N = 20). Similar amounts of fluid were given in the two groups. Intraoperatively, dobutamine was given in 45 % optimized patients but in no control patients. Major complications occurred more frequently in the optimized group [19 (95 %) versus 10 (40 %) in the control group, P < 0.001]. Likewise, SOFA scores were higher in the optimized group on POD1 (10.2 ± 2.5 versus 6.6 ± 2.2 in the control group, P = 0.001), POD2 (8.4 ± 2.6 vs 5.0 ± 2.4 in the control group, P = 0.002) and POD 3 (5.2 ± 3.6 and 2.2 ± 1.3 in the control group, P = 0.01). There was no significant difference in hospital mortality (13 % in the control group and 25 % in the optimized group). Haemodynamic optimization based on volumetric and flow PiCCO-derived parameters was associated with a less favorable postoperative outcome compared with a conventional GDT protocol during emergency surgery.

A randomized trial of goal directed vs. standard fluid therapy in cytoreductive surgery with hyperthermic intraperitoneal chemotherapy

The use of adequate fluid therapy during cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) remains controversial. The aim of the study was to assess whether the use of fluid therapy protocol combined with goal-directed therapy (GDT) is associated with a significant change in morbidity, length of hospital stay, and mortality compared to standard fluid therapy. Patients American Society of Anesthesiologists (ASA) II-III undergoing CRS and HIPEC were randomized into two groups. The GDT group (N = 38) received fluid therapy according to a protocol guided by monitored hemodynamic parameters. The control group (N = 42) received standard fluid therapy. We evaluated incidence of major complications, total length of hospital stay, total amount of fluids administered, and mortality rate. The incidence of major abdominal complications was 10.5% in GDT group and 38.1% in the control group (P = 0.005). The median duration of hospitalization was 19 days in GDT group and 29 days in the control group (P < 0.0001). The mortality rate was zero in GDT group vs. 9.5% in the control group (P = 0.12). GDT group received a significantly (P < 0.0001) lower amount of fluid (5812 ± 1244 ml) than the control group (8269 ± 1452 ml), with a significantly (P < 0.0001) lower volume of crystalloids (3884 ± 1003 vs. 68,528 ± 1413 ml). In CRS and HIPEC, the use of a GDT improves outcome in terms of incidence of major abdominal and systemic postoperative complications and length of hospital stay, compared to standard fluid therapy protocol.

Prevention of renal dysfunction in postoperative elderly patients

PURPOSE OF REVIEW

To describe the effect of ageing on kidney function and to summarize the benefits of advocated measures to prevent perioperative acute kidney injury (AKI) in elderly patients.

RECENT FINDINGS

Given a reduced renal reserve and the burden of comorbidities, the senescent kidney is susceptible to develop perioperative AKI and is less able to recover when injury occurs. Current evidence suggests that preoperative statin therapy, tight glycemic control or urine alkalinization with bicarbonate do not protect the kidneys from harm. The theoretical kidney protective effect of preoperative aspirin therapy or renal vasodilatation with atrial natriuretic peptide or fenoldopam is only supported by low-quality evidence that needs further evaluation. Although questions regarding the amount and timing of fluid resuscitation during surgery are seeking answers in ongoing multicenter studies, the harmful effect of hydroxyethyl starches (HES) and hyperchloremic solutions is now surrounded by strong evidence.

SUMMARY

The future increase in elderly patients being exposed to surgery calls for improved perioperative management to prevent collaterally increased AKI. Although pharmacological therapies aiming to protect the kidneys from harm are under evaluation, hemodynamic optimization and avoidance of nephrotoxic drugs, including HES and hyperchloremic solutions, are critical for the elderly perioperative patient.

Systematic review of preoperative, intraoperative and postoperative risk factors for colorectal anastomotic leaks

BACKGROUND

Anastomotic leak (AL) represents a dreaded complication following colorectal surgery, with a prevalence of 1-19 per cent. There remains a lack of consensus regarding factors that may predispose to AL and the relative risks associated with them. The objective was to perform a systematic review of the literature, focusing on the role of preoperative, intraoperative and postoperative factors in the development of colorectal ALs.

METHODS

A systematic review was performed to identify adjustable and non-adjustable preoperative, intraoperative and postoperative factors in the pathogenesis of AL. Additionally, a severity grading system was proposed to guide treatment.

RESULTS

Of 1707 papers screened, 451 fulfilled the criteria for inclusion in the review. Significant preoperative risk factors were: male sex, American Society of Anesthesiologists fitness grade above II, renal disease, co-morbidity and history of radiotherapy. Tumour-related factors were: distal site, size larger than 3 cm, advanced stage, emergency surgery and metastatic disease. Adjustable risk factors were: smoking, obesity, poor nutrition, alcohol excess, immunosuppressants and bevacizumab. Intraoperative risk factors were: blood loss/transfusion and duration of surgery more than 4 h. Stomas lessen the consequences but not the prevalence of AL. In the postoperative period, CT is the most commonly used imaging tool, with or without rectal contrast, and a C-reactive protein level exceeding 150 mg/l on day 3-5 is the most sensitive biochemical marker. A five-level classification system for AL severity and appropriate management is presented.

CONCLUSION

Specific risk factors and their potential correction or indications for stoma were identified. An AL severity score is proposed to aid clinical decision-making.

The relationship of perioperative fluid administration to outcomes in colorectal and pancreatic surgery: a review of the literature

Optimal perioperative fluid administration in major gastrointestinal surgery remains a challenging clinical problem. Traditional dogma of a liberal approach to fluid administration in order to counteract potential hypovolemia and decreased end-organ perfusion can often result in fluid overload, perhaps negatively impacting perioperative outcomes. This hypothesis has been investigated in several types of gastrointestinal surgery. We discuss the current literature on perioperative fluid administration in colorectal and pancreatic surgery and highlight the controversies that still exist.

Role of intraoperative fluids on hospital length of stay in laparoscopic bariatric surgery: a retrospective study in 224 consecutive patients

BACKGROUND

Studies are unclear regarding optimal intraoperative fluid management during laparoscopic bariatric surgery. The purpose of this 1-year study was to investigate the role of intraoperative fluid administration on hospital length of stay (hLOS) and postoperative complications in laparoscopic bariatric surgery.

METHODS

Patient data analyzed included previously reported demographics, comorbidities, and intraoperative fluid administration on the duration of hLOS and incidence of postoperative complications.

RESULTS

Logistic regression analysis of demographic and comorbidity variables revealed that BMI (P = 0.0099) and history of anemia (P = 0.0084) were significantly associated with hLOS (C index statistic, 0.7). Lower rates of intraoperative fluid administration were significantly associated with longer hLOS (P = 0.0005). Recursive partitioning observed that patients who received <1,750 ml of intraoperative fluids resulted in longer hLOS when compared to patients who received ≥ 1,750 ml (LogWorth = 0.5). When intraoperative fluid administration rates were defined by current hydration guidelines for major abdominal surgery, restricted rates (<5 ml/kg/h) were associated with the highest incidence of extended hLOS (>1 postoperative day) at 54.1 % when compared to 22.9 % with standard rates (5-7 ml/kg/h) and were lowest at 14.5 % in patients receiving liberal rates (>7 ml/kg/h) (P < 0.0001). Finally, lower rates of intraoperative fluid administration were significantly associated with delayed wound healing (P = 0.03).

CONCLUSIONS

The amount of intravenous fluids administered during laparoscopic bariatric surgery plays a significant role on hLOS and on the incidence of delayed wound healing.

The year in cardiothoracic and vascular anesthesia: selected highlights from 2013

This article reviewed selected research highlights of 2013 that pertain to the specialty of cardiothoracic and vascular anesthesia. The first major theme is the commemoration of the sixtieth anniversary of the first successful cardiac surgical procedure with cardiopulmonary bypass conducted by Dr Gibbon. This major milestone revolutionized the practice of cardiovascular surgery and invigorated a paradigm of mechanical platforms for contemporary perioperative cardiovascular practice. Dr Kolff was also a leading contributor in this area because of his important contributions to the refinement of cardiopulmonary bypass and mechanical ventricular assistance. The second major theme is the diffusion of echocardiography throughout perioperative practice. There are now guidelines and training pathways to guide its generalization into everyday practice. The third major theme is the paradigm shift in perioperative fluid management. Recent large randomized trials suggest that fluids are drugs that require a precise prescription with respect to type, dose, and duration. The final theme is patient safety in the cardiac perioperative environment. A recent expert scientific statement has focused attention on this issue because most perioperative errors are preventable. It is likely that clinical research in this area will blossom because this is a major opportunity for improvement in our specialty. The patient care processes identified in these research highlights will further improve perioperative outcomes for our patients.