Intraoperative crystalloid overload leads to substantial inflammatory infiltration of intestinal anastomoses-a histomorphological analysis

Prevention of hypotension after induction of general anesthesia using point-of-care ultrasound to guide fluid management: a randomized controlled trial

PURPOSE

Hypotension after induction of general anesthesia (GAIH) is common and is associated with postoperative complications including increased mortality. Collapsibility of the inferior vena cava (IVC) has good performance in predicting GAIH; however, there is limited evidence whether a preoperative fluid bolus in patients with a collapsible IVC can prevent this drop in blood pressure.

METHODS

We conducted a single-centre randomized controlled trial with adult patients scheduled to undergo elective noncardiac surgery under general anesthesia (GA). Patients underwent a preoperative point-of-care ultrasound scan (POCUS) to identify those with a collapsible IVC (IVC collapsibility index ≥ 43%). Individuals with a collapsible IVC were randomized to receive a preoperative 500 mL fluid bolus or routine care (control group). Surgical and anesthesia teams were blinded to the results of the scan and group allocation. Hypotension after induction of GA was defined as the use of vasopressors/inotropes or a decrease in mean arterial pressure < 65 mm Hg or > 25% from baseline within 20 min of induction of GA.

RESULTS

Forty patients (20 in each group) were included. The rate of hypotension after induction of GA was significantly reduced in those receiving preoperative fluids (9/20, 45% vs 17/20, 85%; relative risk, 0.53; 95% confidence interval, 0.32 to 0.89; P = 0.02). The mean (standard deviation) time to complete POCUS was 4 (2) min, and the duration of fluid bolus administration was 14 (5) min. Neither surgical delays nor adverse events occurred as a result of the study intervention.

CONCLUSION

A preoperative fluid bolus in patients with a collapsible IVC reduced the incidence of GAIH without associated adverse effects.

STUDY REGISTRATION

ClinicalTrials.gov (NCT05424510); first submitted 15 June 2022.

Evaluation of the early use of norepinephrine in major abdominal surgery on medical and surgical postoperative complications: study protocol for a randomised controlled trial (EPON STUDY)

BACKGROUND

Post-induction anaesthesia often promotes intraoperative hypotension (IOH) that can worsen postoperative outcomes. This study aims to assess the benefit of norepinephrine versus ephedrine at the induction of anaesthesia to prevent postoperative complications following major abdominal surgery by preventing IOH.

METHODS AND ANALYSIS

The EPON STUDY is a prospective single-centre randomised controlled trial with the planned inclusion of 500 patients scheduled for major abdominal surgery at the Amiens University Hospital. The inclusion criteria are patients aged over 50 years weighing more than 50 kg with an American Society of Anesthesiologists physical status score of ≥2 undergoing major abdominal surgery under general anaesthesia. Patients are allocated either to the intervention group (n=250) or the standard group (n=250). In the intervention group, the prevention of post-induction IOH is performed with norepinephrine (dilution to 0.016 mg/mL) using an electric syringe pump at a rate of 0.48 mg/h (30 mL/h) from the start of anaesthesia and then titrated to achieve the haemodynamic target. In the control group, the prevention of post-induction IOH is performed with manual titration of ephedrine, with a maximal dose of 30 mg, followed by perfusion with norepinephrine. In both groups, the haemodynamic target to maintain is a mean arterial pressure (MAP) of 65 mm Hg or 70 mm Hg for patients with a medical history of hypertension. An intention-to-treat analysis will be performed. The primary outcome is the Clavien-Dindo score assessed up to 30 days postoperatively. The secondary endpoints are the length of hospital stay and length of stay in an intensive care unit/postoperative care unit; postoperative renal function; postoperative cardiovascular, respiratory, neurological, haematological and infectious complications at 1 month; and volume of intraoperative vascular filling and mortality at 1 month.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the committee of protection of the persons of Ile de France in May 2021 (number 21 05 41). The authors will be involved in disseminating the research findings (through attending conferences and co-authoring papers). The results of the study will be disseminated via peer-reviewed publications and presentations at national and international conferences.

TRIAL REGISTRATION NUMBER

NCT05276596.

Goal-directed fluid management associates with fewer postoperative fluid collections in pancreatoduodenectomy patients

BACKGROUND

The association between perioperative fluid management and complications in pancreatoduodenectomy patients remains controversial. We explored the association between fluid management and radiological signs of complications.

METHODS

We examined pancreatoduodenectomy patients operated between July 2014 and December 2015 (n = 125) and between January 2017 and June 2018 (n = 124). The first cohort received intraoperative fluid management according to a goal-directed strategy and the second cohort was treated conventionally. We analyzed fluid administration, edema visible in computed tomography (CT) scans seven days postoperatively, and radiological signs of complications occurring up to 30 days. We performed multivariable logistic regression analyses to identify risk factors for fluid collections.

RESULTS

No statistically significant difference in postoperative edema via CT scans emerged between the fluid management groups. However, the intraperitoneal space expanded in patients with severe Clavien-Dindo complications compared with patients experiencing mild or no complications (19.1% (IQR 10.4-40.5) vs 2.5% (IQR -7.9-16.6), p = 0.004). Fluid collections were less frequent in the goal-directed group than in the conventional fluid management group (16.8% vs 34.7%, p = 0.001). Risk factors for fluid collections included main pancreatic duct size ≤3 mm, less intraoperative fluid volume accompanying conventional fluid management, a lower postoperative urine output, and postoperative congestive heart failure. The goal-directed group received more intraoperative fluids than the conventional fluid management group and postoperative urine output was higher in the goal-directed group on postoperative days 1-3.

CONCLUSIONS

Optimization of intraoperative fluid management through target-controlled strategies and early diuresis were associated with a lower frequency of fluid collections in postoperative CT.

Postoperative aggressive diuresis prevents postoperative tissue edema and complications in patients undergoing distal pancreatectomy

PURPOSE

Intraoperative fluid restriction is reported to be associated with reduced postoperative tissue edema and decreased incidence of postoperative pancreatic fistula (POPF) in pancreatic surgery. However, there is limited information regarding the postoperative approach to prevent postoperative tissue edema and reduce POPF.

METHODS

Patients undergoing distal pancreatectomy from 2013 to 2018 in our institute were retrospectively enrolled (n = 128). The patients were classified into the two groups: an early diuresis group (ED group: patients administered diuretic agents on postoperative day 2 or earlier between 2016 and 2018, n = 69) and a conventional diuresis group (CD group: patients administered diuretic agents on postoperative day 3 or later between 2013 and 2015, n = 59). Postoperative tissue edema assessed by CT imaging and the incidence of clinically relevant POPF (CR-PF; grade B or C) were compared.

RESULTS

Postoperative tissue edema was significantly reduced in the ED group (p < 0.0001). The incidence of CR-PF was lower in the ED group (19% vs. 32%, p = 0.082), especially in patients with postoperative diuresis on POD 1 (12%, p = 0.044).

CONCLUSION

Early and aggressive postoperative diuresis potentially reduced postoperative visceral tissue edema. This postoperative approach to prevent tissue edema may reduce the incidence of CR-PF in pancreatic surgery.

Assessment of Volume Status and Fluid Responsiveness in Small Animals

Intravenous fluids are an essential component of shock management in human and veterinary emergency and critical care to increase cardiac output and improve tissue perfusion. Unfortunately, there are very few evidence-based guidelines to help direct fluid therapy in the clinical setting. Giving insufficient fluids and/or administering fluids too slowly to hypotensive patients with hypovolemia can contribute to continued hypoperfusion and increased morbidity and mortality. Similarly, giving excessive fluids to a volume unresponsive patient can contribute to volume overload and can equally increase morbidity and mortality. Therefore, assessing a patient's volume status and fluid responsiveness, and monitoring patient's response to fluid administration is critical in maintaining the balance between meeting a patient's fluid needs vs. contributing to complications of volume overload. This article will focus on the physiology behind fluid responsiveness and the methodologies used to estimate volume status and fluid responsiveness in the clinical setting.

[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.

Goal-directed hemodynamic therapy versus restrictive normovolemic therapy in major open abdominal surgery: A randomized controlled trial

BACKGROUND

The aim of this study was to compare the occurrence of postoperative complications in patients undergoing elective open abdominal surgery and receiving intraoperative goal-directed hemodynamic therapy or restrictive normovolemic therapy.

METHODS

A total of 401 patients were randomized in the goal-directed hemodynamic therapy or restrictive normovolemic therapy groups. A cardiac output monitor was used in all goal-directed hemodynamic therapy patients and was left at the discretion of anesthetists in charge of patients in the restrictive normovolemic therapy group. The primary outcome was a composite morbidity endpoint (30-day mortality and complications grade 2-4 according to Dindo-Clavien classification). Secondary outcomes were the hospital duration of stay, the incidence of pulmonary, cardiovascular, and renal complications up to 30 days after surgery, and midterm survival.

RESULTS

Intraoperatively, the goal-directed hemodynamic therapy group received higher intravenous fluid volumes (mean of 10.8 mL/kg/h and standard deviation of 4.0) compared with the restrictive normovolemic therapy group (mean of 7.2 mL/kg/h and standard deviation of 2.0; P < .001). On the first postoperative day, similar fluid volumes were infused in the 2 groups. The primary outcome occurred in 57.7% of goal-directed hemodynamic therapy and 53.0% of restrictive normovolemic therapy (relative risk, 1.09 [95% confidence interval, 0.91-1.30]), and there was no significant difference between groups for any secondary outcomes.

CONCLUSION

Among patients undergoing major open abdominal surgery, the goal-directed hemodynamic therapy and the restrictive normovolemic therapy were associated with similar incidence of moderate-to-severe postoperative complications and hospital resource use.

ERAS pathway in colorectal surgery: structured implementation program and high adherence for improved outcomes

Although there is clear evidence that an Enhanced Recovery After Surgery (ERAS) program in colorectal surgery leads to significantly reduced morbidity rates and length of hospital stay (LOS), it is still unclear what modalities and levels of implementation of the program are necessary to achieve these results. The purpose of this study is to analyze the methods and results of the first year of structured implementation of a colorectal ERAS program in two surgical units of the Azienda Sanitaria Unica Regionale (ASUR) Marche in Italy. A two-center observational study on a prospectively maintained database was performed on 196 consecutive colorectal resections (excluding emergencies and American Society of Anesthesiologists class > III cases) over a 1-year period. More than 50 variables including adherence to the individual items of the ERAS program were considered. Primary outcomes were overall morbidity, major morbidity, mortality and anastomotic leakage rates; secondary outcomes were LOS, re-admission and re-operation. The results were evaluated by univariate and multivariate analyses through logistic regression. After a median follow-up of 39.5 days, we recorded complications in 72 patients (overall morbidity 36.7%), major complications in 14 patients (major morbidity 7.1%), 6 deaths (mortality 3.1%), anastomotic dehiscence in 9 cases (4.9%), mean overall LOS of 6.6 days, 10 readmissions (5.1%) and 13 reoperations (6.7%). The mean adherence rate to the items of the ERAS program was 85.4%, showing a significant dose-effect curve for overall and major morbidity rates, anastomotic leakage rates and LOS. The implementation methods of a colorectal ERAS program in this study led to a high adherence (> 80%) to the program items. High adherence had significant effects also on major morbidity and anastomotic leakage rates.

Fluid Therapy in Patients Undergoing Abdominal Surgery: A Bumpy Road Towards Individualized Management

Prudent intraoperative fluid replacement therapy, inotropes, and vasoactive drugs should be guided by adequate hemodynamic monitoring. The study aimed to evaluate the single-centre practice on intraoperative fluid therapy in abdominal surgery (AS). The evaluation, based on a review of medical files, included 235 patients (103 men), aged 60 ± 15 years who underwent AS between September and November 2017. Fluid therapy was analyzed in terms of quality and quantity. There were 124 high-risk patients according to the American Society of Anaesthesiologists Classification (ASA Class 3+) and 89 high-risk procedures performed. The median duration of procedures was 175 (IQR 106-284) min. Eleven patients died post-operatively. The median fluids volume was 10.4 mL/kg/h of anaesthesia, including 9.1 mL/kg/h of crystalloids and 2.7 mL/kg/h of synthetic colloids. Patients undergoing longer than the median procedures received significantly fewer fluids than those who underwent shorter procedures. The volume of fluids in the longer procedures depended on the procedural risk classification and was significantly greater in high-risk patients undergoing high-risk surgery. Patients who died received significantly more fluids than survivors. In all patients, a non-invasive blood pressure monitoring was used and only six patients had therapy guided by metabolic equilibrium. The fluid therapy used was liberal but complied with the recommendations regarding the type of fluid and risk-adjusted dosing. Hemodynamic monitoring was suboptimal and requires modifications. In conclusion, the optimization of intraoperative fluid therapy requires a balanced and standardized approach consistent with treatment procedures.

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.

Recurring Anastomotic Leak-A Prospective Clinicopathological Investigation of a Distinct Disease Pattern

BACKGROUND

Intestinal anastomotic insufficiency (AI) is a common problem in visceral surgery associated with overexpression of matrix metalloproteinases (MMPs). In some patients it occurs more than once. The etiology of recurring anastomotic insufficiency (RAI) is not understood yet and should be addressed as an independent disease entity.

MATERIALS AND METHODS

Thirty nine consecutive patients with AI were treated at our university center and were included in this prospective study. Clinical data were evaluated by correlative statistical analysis to identify independent risk factors for RAI. Patients were divided in two groups: 18 patients had a single operative revision until restoration (group SAI), and 21 patients had two or more revisions (group RAI). Anastomotic tissue samples as well as untouched bowel wall were collected during reoperations for analysis of MMPs and tissue inhibitor of metalloproteinases (TIMP2). Clinical data were correlated with pathological observations.

RESULTS

Significant differences of clinical and molecular pathological data were found between the two groups. Transfusion of red blood cells until the first reoperation and alcohol abuse led to RAI and were the only independent risk factors for RAI in multivariate analysis. Overexpression of MMP-8, -9, and -13 in anastomotic tissue correlated with the administration of red blood cells during initial operation. Reduced expression of TIMP2 was frequent in nearly all patients without differences throughout the subgroups.

CONCLUSIONS

RAI seems to have an independent disease pattern. Transfusion of blood products is not only a known risk factor for AI but seems to significantly disturb the anastomotic healing process leading to RAI.

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.

Perioperative Net Fluid Balance Predicts Pancreatic Fistula After Pancreaticoduodenectomy

BACKGROUND

Our goal was to evaluate the relationship between perioperative fluid administration and the development of clinically relevant postoperative pancreatic fistula (CR-POPF) after pancreaticoduodenectomy (PD).

METHODS

Retrospectively, we analyzed fluid balance over the first 72 h in 104 consecutive patients who underwent PD between 2013 and 2017. Patients were categorized into tertiles (low, medium, and high) by net fluid balance.

RESULTS

POPF was identified in 17.3% of patients (n = 18). No significant demographic differences were identified among tertiles. Similarly, there were no differences in ASA, smoking status, hemoglobin A1C, pathologic findings, operative time, blood loss, intraoperative fluid administration, use of pancreatic stents, use of epidurals, or postoperative lactate. Patients with high 72-h net fluid balance had significantly increased rates of POPF compared with those in the medium and low tertiles (31.4% vs. 11.4% vs. 8.8%, p = 0.02). On multivariate analysis, increasing net fluid balance remained associated with CR-POPF (OR 1.26, CI 1.03-1.55, p = 0.03).

CONCLUSION

High net 72-h fluid balance is an independent predictor of POPF after PD. Given ongoing efforts to minimize PD morbidity, net fluid balance may represent a clinical predictor and, possibly, a modifiable target for prevention of POPF.

Postoperative hemodynamic instability and monitoring

PURPOSE OF REVIEW

The purpose of the review is to identify the recently validated minimally invasive or noninvasive monitoring devices used to both monitor and guide resuscitation in the critically ill patients.

RECENT FINDINGS

Recent advances in noninvasive measures of blood pressure, blood flow, and vascular tone have been validated and complement existing minimally invasive and invasive monitoring techniques. These monitoring approaches should be used within the context of a focused physical examination and static vital sign analysis. When available, measurement of urinary output is often included. All studies show that minimally invasive and noninvasive measure of arterial pressure and cardiac output are possible and often remain as accurate as invasive measures. The noninvasive techniques degrade in severe circulatory failure and the use of vasopressor therapy. Importantly, these output parameters form the treatment goals for many goal-directed therapies protocols.

SUMMARY

When coupled with a focused physical examination and functional hemodynamic monitoring analyses, these measures become even more specific at defining volume responsiveness and vasomotor tone and can be used to drive resuscitation strategies.

Postoperative Visceral Tissue Edema Assessed by Computed Tomography Is a Predictor for Severe Complications After Pancreaticoduodenectomy

BACKGROUND/AIMS

In pancreatoduodenectomy (PD), the adverse impact of tissue edema owing to intraoperative fluid overload remains unclear. This study aims to evaluate how visceral tissue edema due to fluid overload affects severe postoperative complications after PD. It aims to clarify the usefulness of assessment by computed tomography (CT) of postoperative tissue edema.

METHODS

We classified 200 patients who underwent PD as either liberal fluid management (LFM) group (n = 100) or goal-directed fluid therapy (GDFT) group (n = 100), based on intraoperative fluid management. We assessed postoperative tissue edema by cross section of the body trunk area using pre- and postoperative CT.

RESULTS

Severe complication (Clavien-Dindo more than grade III) rate was significantly higher in LFM group than GDFT group (37 vs. 17%, P = 0.001). Independent risk factors of severe complications after PD included diameter of main pancreatic duct ≤ 3 mm at the cut surface (P = 0.041; OR 2.274; 95% CI 1.034-5.001), LFM (P = 0.005; OR 2.720; 95% CI 1.355-5.462), and increased rate of body trunk area ≥ 20% (P < 0.001; OR 3.448; 95% CI 1.723-5.462). In subgroup analysis of patients with no transfusion, LFM and increased rate of body trunk area ≥ 20% were independent risk factors of severe postoperative complications.

CONCLUSIONS

Visceral tissue edema evaluation is a valuable method to predict severe complications after PD.

Hypertonic saline in critical illness - A systematic review

INTRODUCTION

The optimal approach to fluid management in critically ill patients is highly debated. Fluid resuscitation using hypertonic saline was used in the past for more than thirty years, but has recently disappeared from clinical practice. Here we provide an overview on the currently available literature on effects of hypertonic saline infusion for fluid resuscitation in the critically ill.

METHODS

Systematic analysis of reports of clinical trials comparing effects of hypertonic saline as resuscitation fluid to other available crystalloid solutions. A literature search of MEDLINE and the Cochrane Controlled Clinical trials register (CENTRAL) was conducted to identify suitable studies.

RESULTS

The applied search strategy produced 2284 potential publications. After eliminating doubles, 855 titles and abstracts were screened and 40 references retrieved for full text analysis. At total of 25 scientific studies meet the prespecified inclusion criteria for this study.

CONCLUSION

Fluid resuscitation using hypertonic saline results in volume expansion and less total infusion volume. This may be of interest in oedematous patients with intravascular volume depletion. When such strategies are employed, renal effects may differ markedly according to prior intravascular volume status. Hypertonic saline induced changes in serum osmolality and electrolytes return to baseline within a limited period in time. Sparse evidence indicates that resuscitation with hypertonic saline results in less perioperative complications, ICU days and mortality in selected patients. In conclusion, the use of hypertonic saline may have beneficial features in selected critically ill patients when carefully chosen. Further clinical studies assessing relevant clinical outcomes are warranted.

Pancreatoduodenectomy and the risk of complications from perioperative fluid administration

BACKGROUND

The dogma of administering sufficient intravenous fluids aggressively to avoid under-resuscitation has recently been challenged. Evidence suggests that excessive perioperative fluid administration may be associated with negative clinical outcomes in gastrointestinal surgery. This study examines the impact of fluid administration on perioperative outcomes in patients undergoing pancreatoduodenectomy (PD).

METHODS

A retrospective analysis of 202 patients undergoing PD between January 2004 and August 2015 was performed. A cut-off value of 10 mL/kg/h was applied (low fluid group: <10 mL/kg/h versus high fluid group: ≥10 mL/kg/h).

RESULTS

There were 76 patients in the low fluid group and 126 patients in the high fluid group. Both groups had comparable age, American Society of Anesthesiologists score and preoperative morbidity rates. Patients in the high fluid group received significantly more total fluids, crystalloids and colloids intraoperatively (P < 0.0001, P < 0.0001 and P = 0.013, respectively) without a significant difference in estimated blood loss (P = 0.586). The net fluid balance on post-operative day 0 was also significantly higher in the high fluid group (P < 0.0001). The mortality rate was 0% in the cohort. Major morbidity rate was 46.1% and 44.4% in low and high fluid groups, respectively (P = 0.836). Reoperation rate was 5.3% for the low fluid group and 1.6% for the high fluid group (P = 0.136). There were no significant differences between the groups for any of the individual complications.

CONCLUSION

This study did not identify a difference in post-operative outcomes between the low and high fluid regime in patients undergoing PD.

Complications after pancreaticoduodenectomy are associated with higher amounts of intra- and postoperative fluid therapy: A single center retrospective cohort study

Background

Perioperative mortality after pancreaticoduodenectomy has decreased significantly in high-volume centers, but morbidity remains high. Restrictive perioperative fluid management may contribute to reduced complication rates after various surgical procedures. The aim of this study was to determine whether there is a correlation between the amount of fluid administered and postoperative complications. We hypothesized that higher amounts of intra- and total fluid is associated with greater postoperative morbidity.

Materials and methods

We retrospectively examined data of 553 patients who underwent pancreaticoduodenectomy at University of Freiburg Medical Center between 2001 and 2013. Data on intra - and postoperative fluid administration (until postoperative day 5) were obtained from anesthesiological and surgical records. Data on complications were retrieved from our institutional pancreatic database.

Results

The median values for intra- and total fluid administered were 6000 ml (range 400–15,000 ml) and 13,600 ml (range 5000–57,700 ml), respectively. The overall in-hospital mortality was 1.9% (no correlation with fluid administration). Patients who received more than 6000 ml intraoperative fluid had more wound infections (P = 0.049), intra-abdominal abscesses (P = 0.020) and postoperative interventions (P = 0.007). In patients who received more than 14000 ml fluid until postoperative day 5 all evaluated types of postoperative complications (infectious, fistula, delayed gastric emptying, bleeding) and re-interventions occurred significantly more frequently than in patients who received less than 14,000 ml (P < 0.05–0.001).

Conclusions

Higher amounts of fluids may contribute to postoperative complications. More studies are needed to adequately assess the use of intra/postop fluid therapy.

•

High amounts of perioperative fluid may impair surgical outcome of pancreatic resection.

•

>6000 ml intraoperative fluid was associated with more infectious complications.

•

>14 000 ml total fluid by postoperative day 5 was linked with many complications.

•

Complications included infections, fistulas, delayed gastric emptying and bleeding.

•

Prospective randomized controlled trials should investigate postoperative fluid therapy.

Plasma pro-atrial natriuretic peptide to estimate fluid balance during open and robot-assisted esophagectomy: a prospective observational study

Background

It remains debated how much fluid should be administered during surgery. The atrial natriuretic peptide precursor proANP is released by atrial distension and deviations in plasma proANP are reported associated with perioperative fluid balance. We hypothesized that plasma proANP would decrease when the central blood volume is compromised during the abdominal part of robot-assisted hybrid (RE) esophagectomy and that a positive fluid balance would be required to maintain plasma proANP.

Methods

Patients undergoing RE (n = 25) or open (OE; n = 25) esophagectomy for gastroesophageal cancer were included consecutively in this prospective observational study. Plasma proANP was determined repetitively during esophagectomy to allow for distinction between the abdominal and thoracic part of the procedure. The RE group was 15° head up tilted during the abdominal procedure.

Results

The blood loss was 250 (150–375) (RE) and 600 ml (390–855) (OE) (p = 0.01), but the two groups of patients were provided with a similar positive fluid balance: 1705 (1390–1983) vs. 1528 ml (1316–1834) (p = 0.4). However, plasma proANP decreased by 21% (p < 0.01) during the abdominal part of RE carried out during moderate head-up tilt, but only by 11% (p = 0.01) during OE where the patients were supine. Plasma proANP and fluid balance were correlated in the RE-group (r = 0.5 (0.073–0.840), p = 0.02) and tended to correlate in the OE group (r = 0.4 (−0.045–0.833), p = 0.08).

Conclusion

The results support that plasma proANP decreases when the central blood volume is compromised and suggest that an about 2200 ml surplus administration of crystalloid is required to maintain plasma proANP during esophagectomy.

Trial registration

Clinicaltrials.gov (NCT02077673). Registered retrospectively February 12^th 2014.

Postoperative fluid overload is a risk factor for adverse surgical outcome in patients undergoing esophagectomy for esophageal cancer: a retrospective study in 335 patients

Background

Restrictive intraoperative fluid management is increasingly recommended for patients undergoing esophagectomy. Controversy still exists about the impact of postoperative fluid management on perioperative outcome.

Methods

We retrospectively examined 335 patients who had undergone esophagectomy for esophageal cancer at the University Hospital Freiburg between 1996 and 2014 to investigate the relation between intra- and postoperative fluid management and postoperative morbidity after esophagectomy.

Results

Perioperative morbidity was 75%, the in-hospital mortality 8%. A fluid balance above average on the operation day was strongly associated with a higher rate of postoperative mortality (21% vs 3%, p < 0.001) and morbidity (83% vs 66%, p = 0.001). Univariate analysis for risk factors for adverse surgical outcome (Clavien ≥ III) identified ASA-score (p = 0.002), smoking (p = 0.036), reconstruction by colonic interposition (p = 0.036), cervical anastomosis (p = 0.017), blood transfusion (p = 0.038) and total fluid balance on the operation day and on POD 4 (p = 0.001) as risk factors.

Multivariate analysis confirmed only ASA-score (p = 0.001) and total fluid balance (p = 0.001) as independent predictors of adverse surgical outcome.

Conclusion

Intra- and postoperative fluid overload is strongly associated with increased postoperative morbidity. Our results suggest restrictive intra- and especially postoperative fluid management to optimize the outcome after esophagectomy.

Fluid therapy in the perioperative setting-a clinical review

BACKGROUND

Perioperative hypovolemia and fluid overload have effects on both complications following surgery and on patient survival. Therefore, the administration of intravenous fluids before, during, and after surgery at the right time and in the right amounts is of great importance. This review aims to analyze the literature concerning perioperative fluid therapy in abdominal surgery and to provide evidence-based recommendations for clinical practice.

RESULTS

Preoperative oral or intravenous administration of carbohydrate containing fluids has been shown to improve postoperative well-being and muscular strength and to reduce insulin resistance. Hence, the intake of fluid (preferably containing carbohydrates) should be encouraged up to 2 h prior to surgery in order to avoid dehydration. Excessive intravenous fluid administration adds to tissue inflammation and edema formation, thereby compromising tissue healing. During major abdominal surgery a "zero-balance" intraoperative fluid strategy aims at avoiding fluid overload (and comparable to the so-called restrictive approach) as well as goal-directed fluid therapy (GDT). Both proved to significantly reduce postoperative complications when compared to "standard fluid therapy". Trials comparing "restrictive" or zero-balance and GDT have shown equal results, as long as fluid overload is avoided in the GDT group as well (categorized as "zero-balance GDT"). It is possible that high-risk surgical patients, such as those undergoing acute surgery, may benefit from the continuous monitoring of circulatory status that the GDT provides. Data on this group of patients is not available at present, but trials are ongoing.

CONCLUSION

In elective surgery, the zero-balance approach has shown to reduce postoperative complications and is easily applied for most patients. It is less expensive and simpler than the zero-balance GDT approach and therefore recommended in this review. In outpatient surgery, 1-2 L of balanced crystalloids reduces postoperative nausea and vomiting and improves well-being.

Reliability of Continuous Non-Invasive Assessment of Hemoglobin and Fluid Responsiveness: Impact of Obesity and Abdominal Insufflation Pressures

BACKGROUND

During surgery, proper fluid resuscitation and hemostatic control is critical. Pleth variability index (PVI) is advocated as a reliable way of optimizing intraoperative fluid resuscitation. PVI is a measure of dynamic change in perfusion index during a complete respiratory cycle. Non-invasive monitoring of total hemoglobin could provide a reliable means to determine need for transfusion. We analyzed the impact of insufflation and obesity on non-invasive measurements of hemoglobin and PVI in laparoscopic procedures to validate reliability of fluid responsiveness and hemoglobin levels.

METHODS

A non-invasive hemoglobin and PVI monitoring device was prospectively analyzed in patients undergoing abdominal operations. Patients were stratified by open and laparoscopic approach and obesity (body mass index (BMI) ≥35). PVI and hemoglobin values were assessed before, during, and after insufflation and compared to control patients undergoing open surgery.

RESULTS

Sixty-three patients were enrolled (mean age 42 years; 71 % male; mean BMI 36) with 24 patients laparoscopic non-obese (LNO), 20 laparoscopic obese (LO), and 19 undergoing open operations. There was no significant blood loss. Hemoglobin did not change significantly before or after insufflation. There was false elevation of PVI with insufflation and more pronounced in obese patients.

CONCLUSIONS

Insufflation or obesity was not associated with significant variations in hemoglobin. Non-invasive monitoring of hemoglobin is useful in laparoscopic procedures in obese and non-obese patients. PVI values should be used cautiously during laparoscopic procedures, particularly in obese patients.

Perioperative cardiovascular monitoring of high-risk patients: a consensus of 12

A significant number of surgical patients are at risk of intra- or post-operative complications or both, which are associated with increased lengths of stay, costs, and mortality. Reducing these risks is important for the individual patient but also for health-care planners and managers. Insufficient tissue perfusion and cellular oxygenation due to hypovolemia, heart dysfunction or both is one of the leading causes of perioperative complications. Adequate perioperative management guided by effective and timely hemodynamic monitoring can help reduce the risk of complications and thus potentially improve outcomes. In this review, we describe the various available hemodynamic monitoring systems and how they can best be used to guide cardiovascular and fluid management in the perioperative period in high-risk surgical patients.

Perioperative fluid therapy: a statement from the international Fluid Optimization Group

BACKGROUND

Perioperative fluid therapy remains a highly debated topic. Its purpose is to maintain or restore effective circulating blood volume during the immediate perioperative period. Maintaining effective circulating blood volume and pressure are key components of assuring adequate organ perfusion while avoiding the risks associated with either organ hypo- or hyperperfusion. Relative to perioperative fluid therapy, three inescapable conclusions exist: overhydration is bad, underhydration is bad, and what we assume about the fluid status of our patients may be incorrect. There is wide variability of practice, both between individuals and institutions. The aims of this paper are to clearly define the risks and benefits of fluid choices within the perioperative space, to describe current evidence-based methodologies for their administration, and ultimately to reduce the variability with which perioperative fluids are administered.

METHODS

Based on the abovementioned acknowledgements, a group of 72 researchers, well known within the field of fluid resuscitation, were invited, via email, to attend a meeting that was held in Chicago in 2011 to discuss perioperative fluid therapy. From the 72 invitees, 14 researchers representing 7 countries attended, and thus, the international Fluid Optimization Group (FOG) came into existence. These researches, working collaboratively, have reviewed the data from 162 different fluid resuscitation papers including both operative and intensive care unit populations. This manuscript is the result of 3 years of evidence-based, discussions, analysis, and synthesis of the currently known risks and benefits of individual fluids and the best methods for administering them.

RESULTS

The results of this review paper provide an overview of the components of an effective perioperative fluid administration plan and address both the physiologic principles and outcomes of fluid administration.

CONCLUSIONS

We recommend that both perioperative fluid choice and therapy be individualized. Patients should receive fluid therapy guided by predefined physiologic targets. Specifically, fluids should be administered when patients require augmentation of their perfusion and are also volume responsive. This paper provides a general approach to fluid therapy and practical recommendations.

The HYSLAR trial: a prospective randomized controlled trial of the use of a restrictive fluid regimen with 3% hypertonic saline versus lactated Ringers in patients undergoing pancreaticoduodenectomy

OBJECTIVE

This study was designed to determine whether the volume and type of fluid administered for pancreaticoduodenectomy impacts postoperative outcomes.

BACKGROUND

Three percent hypertonic saline (HYS) has been suggested as a means of reducing the volume of fluid required to sustain tissue perfusion in the perioperative period.

METHODS

Between May 2011 and November 2013, patients undergoing pancreaticoduodenectomy were enrolled in an institutional review board-approved, single-center, prospective, parallel, randomized controlled trial (NCT 01428050), comparing lactated Ringers (LAR) (15 mL/kg/hr LAR intraoperation, 2 mL/kg/hr LAR postoperation) with HYS (9 mL/kg/hr LAR and 1 mL/kg/hr HYS intraoperation, 1 mL/kg/hr HYS postoperation).

RESULTS

A total of 264 patients were randomized. Demographic variables between groups were similar. The HYS patients had a significantly reduced net fluid balance (65 vs 91 mL/kg, P = 0.02). The overall complication rate was reduced in the HYS group (43% vs 54%), with a relative risk of 0.79 [95% confidence interval (CI), 0.62-1.02; P = 0.073], factoring stratification for pancreas texture. After adjustment for age and weight, the relative risk was 0.75 [95% CI (0.58-0.96); P = 0.023]. The total number of complications was significantly reduced in the HYS group (93 vs 123), with an incidence rate ratio of 0.74 [95% CI (0.56-0.97); P = 0.027]. After adjustment for age and weight, the incidence rate ratio was 0.69 [95% CI (0.52-0.90); P = 0.0068]. Reoperations, length of stay, readmissions, and 90-day mortality were similar between groups.

CONCLUSIONS

A moderately restrictive fluid regimen with HYS resulted in a statistically significant 25% reduction in complications when adjusted for age, weight, and pancreatic texture.

A prospective clinical study evaluating the development of bowel wall edema during laparoscopic and open visceral surgery

BACKGROUND

To examine bowel wall edema development in laparoscopic and open major visceral surgery.

METHODS

In a prospective study, 47 consecutively operated patients with gastric and pancreatic resections were included. Twenty-seven patients were operated in a conventional open procedure (open group) and 20 in a laparoscopic fashion (lap group). In all procedures, a small jejunal segment was resected during standard preparation, of which we measured the dry-wet ratio. Furthermore, HE staining was performed for measuring of bowel wall thickness and edema assessment.

RESULTS

Mean value (±std) of dry-wet ratio was significantly lower in the open than in the lap group (0.169 ± 0.017 versus 0.179 ± 0.015; p = 0.03) with the same amount of fluid administration in both groups and a longer infusion interval during laparoscopic surgery. Subgroup analyses (only pancreatic resections) still showed similar results. Histologic examination depicted a significantly larger bowel wall thickness in the open group.

CONCLUSIONS

Laparoscopic surgery does not seem to lead to the bowel wall edema observed to occur in open surgery regardless of the degree of intravenous fluid administration, thus supporting its use even in major visceral surgery.

Crystalloid and colloid therapy

Fluid therapy is a cornerstone of emergency medicine, but equine practitioners should be aware of recent developments that have modified previous recommendations. First, new emphasis on the avoidance of hyperchloremia suggests that crystalloids with a lower chloride concentration may be more appropriate for use. Second, modifications to the understanding of the Starling equation suggest that the benefits of colloids may be more limited than previously thought. In addition, the negative effects of fluid overload on morbidity and mortality are becoming increasingly recognized. Although more specific research in horses is needed, these principles are likely to apply across all species.

Impact of intraoperative temperature and humidity on healing of intestinal anastomoses

PURPOSE

Clinical data indicate that laparoscopic surgery has a beneficial effect on intestinal wound healing and is associated with a lower incidence of anastomotic leakage. This observation is based on weak evidence, and little is known about the impact of intraoperative parameters during laparoscopic surgery, e.g., temperature and humidity.

METHODS

A small-bowel anastomosis was formed in rats inside an incubator, in an environment of stable humidity and temperature. Three groups of ten Wistar rats were operated: a control group (G1) in an open surgical environment and two groups (G2 and G3) in the incubator at a humidity of 60 % and a temperature of 30 and 37 °C (G2 and G3, respectively). After 4 days, bursting pressure and hydroxyproline concentration of the anastomosis were analyzed. The tissue was histologically examined. Serum levels of C-reactive-protein (CRP) were measured.

RESULTS

No significant changes were seen in the evaluation of anastomotic stability. Bursting pressure was very similar among the groups. Hydroxyproline concentration in G3 (36.3 μg/g) was lower by trend (p = 0.072) than in G1 (51.7 μg/g) and G2 (46.4 μg/g). The histological evaluation showed similar results regarding necrosis, inflammatory cells, edema, and epithelization for all groups. G3 (2.56) showed a distinctly worse score for submucosal bridging (p = 0.061) than G1 (1.68). A highly significant increase (p = 0.008) in CRP was detected in G3 (598.96 ng/ml) compared to G1 (439.49 ng/ml) and G2 (460 ng/ml).

CONCLUSION

A combination of high temperature and humidity during surgery induces an increased systemic inflammatory response and seems to be attenuating the early regeneration process in the anastomotic tissue.