Intraoperative splanchnic hypoperfusion, increased intestinal permeability, down-regulation of monocyte class II major histocompatibility complex expression, exaggerated acute phase response, and sepsis

Prospective flow cytometry analysis of leucocyte subsets in critically ill patients who develop sepsis: a pilot study

PURPOSE

Sepsis in critically ill patients with injury bears a high morbidity and mortality. Extensive phenotypic monitoring of leucocyte subsets in critically ill patients at ICU admission and during sepsis development is still scarce. The main objective of this study was to identify early changes in leukocyte phenotype which would correlate with later development of sepsis.

METHODS

Patients who were admitted in a tertiary ICU for organ support after severe injury (elective cardiac surgery, trauma, necessity of prolonged ventilation or stroke) were sampled on admission (T1) and 48-72 h later (T2) for phenotyping of leukocyte subsets by flow cytometry and cytokines measurements. Those who developed secondary sepsis or septic shock were sampled again on the day of sepsis diagnosis (Tx).

RESULTS

Ninety-nine patients were included in the final analysis. Nineteen (19.2%) patients developed secondary sepsis or septic shock. They presented significantly higher absolute monocyte counts and CRP at T1 compared to non-septic patients (1030/µl versus 550/µl, p = 0.013 and 5.1 mg/ml versus 2.5 mg/ml, p = 0.046, respectively). They also presented elevated levels of monocytes with low expression of L-selectin (CD62Lneg monocytes) (OR[95%CI] 4.5 (1.4-14.5), p = 0.01) and higher SOFA score (p < 0.0001) at T1 and low mHLA-DR at T2 (OR[95%CI] 0.003 (0.00-0.17), p = 0.049). Stepwise logistic regression analysis showed that both monocyte markers and high SOFA score (> 8) were independently associated with nosocomial sepsis occurrence. No other leucocyte count or surface marker nor any cytokine measurement correlated with sepsis occurrence.

CONCLUSION

Monocyte counts and change of phenotype are associated with secondary sepsis occurrence in critically ill patients with injury.

Optimization of the target strategy of perioperative infusion therapy based on monitoring data of central hemodynamics in order to prevent complications

Enhanced Recovery After Surgery (ERAS) protocols are increasingly used in the perioperative period around the world. The concept of goal-directed fluid therapy (GDT) is a key element of the ERAS protocols. Inadequate perioperative infusion therapy can lead to a number of complications, including the development of an infectious process, namely surgical site infections, pneumonia, urinary tract infections. Optimal infusion therapy is difficult to achieve with standard parameters (e.g., heart rate, blood pressure, central venous pressure), so there are various methods of monitoring central hemodynamics - from invasive, minimally invasive to non-invasive. The latter are increasingly used in clinical practice. The current evidence base shows that perioperative management, specifically the use of GDT guided by real-time, continuous hemodynamic monitoring, helps clinicians maintain a patient's optimal fluid balance. The manuscript presents the analytical data, which describe the benefits and basic principles of perioperative targeted infusion therapy based on central hemodynamic parameters to reduce the risk of complications.

Infection Route of Parvimonas micra: A Case Report and Systematic Review

Parvimonas micra (P. micra), a bacterium that colonizes the gastrointestinal tract, is often isolated from periodontitis and abscesses as part of a complex bacterial infection. However, reports of monobacterium infections due to P. micra are limited. Here, we report a case of monobacterial bacteremia caused by P. micra with the aim of identifying the source of the invasion and clarifying the clinical features. A 54-year-old patient presented with bacteremia due to P. micra and with an oral invasion that we suspected resulted from prior dental treatment. Using PubMed and Google Scholar databases, we undertook a systematic review of monobacteremia caused by P. micra. We identified 26 patients (mean age, 70.15 years) in our systematic review. P. micra bacteremia and its associated phenotypes were most frequently identified in spinal discitis, followed by epidural and lumbar abscesses, and infective endocarditis. The major risk factors were malignancy, diabetes mellitus, and post-arthroplasty. When P. micra is detected in blood cultures, evaluation and intervention for oral contamination may be indicated.

Perspective: Drawing on Findings From Critical Illness to Explain Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

We propose an initial explanation for how myalgic encephalomyelitis / chronic fatigue syndrome (ME/CFS) could originate and perpetuate by drawing on findings from critical illness research. Specifically, we combine emerging findings regarding (a) hypoperfusion and endotheliopathy, and (b) intestinal injury in these illnesses with our previously published hypothesis about the role of (c) pituitary suppression, and (d) low thyroid hormone function associated with redox imbalance in ME/CFS. Moreover, we describe interlinkages between these pathophysiological mechanisms as well as “vicious cycles” involving cytokines and inflammation that may contribute to explain the chronic nature of these illnesses. This paper summarizes and expands on our previous publications about the relevance of findings from critical illness for ME/CFS. New knowledge on diagnostics, prognostics and treatment strategies could be gained through active collaboration between critical illness and ME/CFS researchers, which could lead to improved outcomes for both conditions.

A postresection perfusion deficit in the right colon is an independent predictor of perioperative outcome after major hepatectomy

BACKGROUND

There is a strong interaction between hepatic hemodynamics and perfusion in the splanchnic system. However, little is known about differences in perfusion in different splanchnic compartments and their changes after hepatectomy.

METHODS

Perfusion in various splanchnic compartments (ie, stomach, small intestine, right and left colon, liver) was assessed pre- and post-hepatectomy by intraoperative laser Doppler flowmetry. Differences of splanchnic perfusion between compartments were evaluated by ANOVA, and risk factors of postoperative complications (graded by the comprehensive complication index [CCI]) were analyzed by univariate and multivariate analyses. A prediction model of postoperative complications was developed.

RESULTS

A total of 50 and 29 patients with major and minor hepatectomy were enrolled. Splanchnic perfusion at baseline varied significantly across different splanchnic compartments with highest values in the small bowel and right colon (P < .001). Major hepatectomy induced a significant perfusion decrease in the stomach (P = .006), right colon (P < .001) and small bowel (P = .035). A postresection perfusion deficit in the right colon with values below 254 perfusion units (PU) was identified as an independent predictor of clinically relevant complications after major hepatectomy (concordance index: 0.79, 95% CI 0.66-0.87, P = .002). Bootstrap validation confirmed internal validity and excellent calibration.

CONCLUSIONS

Major hepatectomy causes significant reduction of splanchnic perfusion. An intraoperative posthepatectomy microcirculatory perfusion deficit of the right colon is a strong and independent predictor of clinically relevant postoperative complications after major hepatectomy.

Goal-Directed Fluid Therapy Based on Pulse-Pressure Variation Compared with Standard Fluid Therapy in Patients Undergoing Complex Spine Surgery: A Randomized Controlled Trial

Study Design

Prospective, randomized, controlled study.

Purpose

To determine whether the use of goal-directed fluid therapy (GDT) guided by pulse-pressure variation (PPV) and fluid management protocol can reduce intraoperative hypotension, blood transfusion requirements, and postoperative complications in adults undergoing complex spine surgery.

Overview of Literature

Complex spine surgeries involve a significant risk of blood loss and intraoperative hypotension. Previous studies showed that GDT reduces intraoperative hypotension and postoperative complications in these surgery types; however, limited information exists about GDT guided by PPV.

Methods

Sixty adults (18–70 years) patients undergoing complex spine surgeries at Siriraj Hospital, Mahidol University, Thailand were enrolled. Patients were allocated to two groups (30 patients in each) using computer-generated randomization. Intraoperative fluid and vasopressor were administrated via either GDT or standard care. The GDT algorithm used PPV and fluid protocol as the primary tool to guide hemodynamic management. The incidences and episodes of perioperative hypotension were measured as the outcomes.

Results

Fifty-seven patients were analyzed (three patients in the GDT group were excluded). The baseline characteristics and surgical procedures of the two groups did not differ significantly. The prevalence of intraoperative hypotension was 80.0% for the control group and 66.7% for the GDT group (p=0.25). Two episodes (1–3) of intraoperative hypotension occurred in the control group, and one episode (0–3) occurred in the GDT group; the difference was not significantly different (p=0.57). The intraoperative blood transfusion requirements and postoperative complications were similar in both the groups. In the subgroup analysis, patients with intraoperative hypotension exhibited a higher incidence of postoperative bowel dysfunction.

Conclusions

PPV-guided GDT and fluid protocol, as compared with standard practice, did not show significant advantages with respect to intraoperative hypotension, blood transfusion, or postoperative complications in patients undergoing complex spine surgery in the prone position.

Personalised haemodynamic management targeting baseline cardiac index in high-risk patients undergoing major abdominal surgery: a randomised single-centre clinical trial

BACKGROUND

Despite several clinical trials on haemodynamic therapy, the optimal intraoperative haemodynamic management for high-risk patients undergoing major abdominal surgery remains unclear. We tested the hypothesis that personalised haemodynamic management targeting each individual's baseline cardiac index at rest reduces postoperative morbidity.

METHODS

In this single-centre trial, 188 high-risk patients undergoing major abdominal surgery were randomised to either routine management or personalised haemodynamic management requiring clinicians to maintain personal baseline cardiac index (determined at rest preoperatively) using an algorithm that guided intraoperative i.v. fluid and/or dobutamine administration. The primary outcome was a composite of major complications (European Perioperative Clinical Outcome definitions) or death within 30 days of surgery. Secondary outcomes included postoperative morbidity (assessed by a postoperative morbidity survey), hospital length of stay, mortality within 90 days of surgery, and neurocognitive function assessed after postoperative Day 3.

RESULTS

The primary outcome occurred in 29.8% (28/94) of patients in the personalised management group, compared with 55.3% (52/94) of patients in the routine management group (relative risk: 0.54, 95% confidence interval [CI]: 0.38 to 0.77; absolute risk reduction: -25.5%, 95% CI: -39.2% to -11.9%; P<0.001). One patient assigned to the personalised management group, compared with five assigned to the routine management group, died within 30 days after surgery (P=0.097). There were no clinically relevant differences between the two groups for secondary outcomes.

CONCLUSIONS

In high-risk patients undergoing major abdominal surgery, personalised haemodynamic management reduces a composite outcome of major postoperative complications or death within 30 days after surgery compared with routine care.

CLINICAL TRIAL REGISTRATION

NCT02834377.

Perioperative Interstitial Fluid Expansion Predicts Major Morbidity Following Pancreatic Surgery: Appraisal by Bioimpedance Vector Analysis

OBJECTIVE

To evaluate whether perioperative bioimpedance vector analysis (BIVA) predicts the occurrence of surgery-related morbidity.

SUMMARY BACKGROUND DATA

BIVA is a reliable tool to assess hydration status and compartimentalized fluid distribution.

METHODS

The BIVA of patients undergoing resection for pancreatic malignancies was prospectively measured on the day prior to surgery and on postoperative day (POD)1. Postoperative morbidity was scored per the Clavien-Dindo classification (CDC), and the Comprehensive Complication Index (CCI).

RESULTS

Out of 249 patients, the overall and major complication rates were 61% and 16.5% respectively. The median CCI was 24 (IQR 0.0-24.2), and 24 patients (9.6%) had a complication burden with CCI≥40. At baseline the impedance vectors of severe complicated patients were shorter compared to the vectors of uncomplicated patients only for the female subgroup (P=0.016). The preoperative extracellular water (ECW) was significantly higher in patients who experienced severe morbidity according to the CDC or not [19.4L (17.5-22.0) vs. 18.2L (15.6-20.6), P=0.009, respectively] and CCI≥40, or not [20.3L (18.5-22.7) vs. 18.3L (15.6-20.6), P=0.002, respectively]. The hydration index on POD1 was significantly higher in patients who experienced major complications than in uncomplicated patients (P=0.020 and P=0.025 for CDC and CCI, respectively).At a linear regression model, age (β=0.14, P=0.035), sex female (β=0.40, P<0.001), BMI (β=0.30, P<0.001), and malnutrition (β=0.14, P=0.037) were independent predictors of postoperative ECW.

CONCLUSION

The amount of extracellular fluid accumulation predicts major morbidity after pancreatic surgery. Female, obese and malnourished patients were at high risk of extracellular fluid accumulation.

The effect of immunonutrition on bacterial translocation after Pringle maneuverer in rats

Introduction

Temporary clamping of the hepatoduodenal ligament (the Pringle manoeuvre) is the most commonly used method to prevent intraoperative blood loss in liver surgery. Some side effects of the Pringle manoeuvre (PM) can occur.

Aim

To investigate the effectiveness of preoperative immunonutritional support to prevent bacterial translocation (BT) in rats due to PM.

Material and methods

Forty Wistar albino rats were randomly divided into four groups. Groups 1 and 2 were fed with normal rat diet and water, and groups 3 and 4 were fed with enteral immunonutrition (Impact Glutamine) containing 1 g/kg/day amino acid in the preoperative period. Group 1 (n = 10) and 4 (n = 10) rats were treated only with laparotomy; group 2 (n = 10) and 3 (n = 10) rats were treated with PM for 30 min with laparotomy. After 30 min, relaparotomy was applied to all groups and portal blood, mesentery, spleen samples were taken for culture purposes.

Results

Proliferation in portal blood cultures was significantly higher in the samples from the normally fed group (group 2) in whom PM was applied, compared to the other groups (p < 0.001). No proliferation was observed in the PM-treated group (group 3), who also received preoperative immunonutritional support.

Conclusions

Preoperative immunonutritional support is effective in the prevention of BT due to PM in rats.

A Dual Protective Effect of Intestinal Remote Ischemic Conditioning in a Rat Model of Total Hepatic Ischemia

The present study aimed to investigate the effects of intestinal remote ischemic preconditioning (iRIC) on ischemia-reperfusion injury (IRI) and gut barrier integrity in a rat model of total hepatic ischemia (THI). Male Wistar rats (n = 50; 250–300 g) were randomly allocated into two experimental groups: RIC/Control. Thirty minutes of THI was induced by clamping the hepatoduodenal ligament. iRIC was applied as 4-min of ischemia followed by 11-min of reperfusion by clamping the superior mesenteric artery. Animals were sacrificed at 1, 2, 6, 24 h post-reperfusion (n = 5/group/timepoint). RIC of the gut significantly improved microcirculation of the ileum and the liver. Tissue ATP-levels were higher following iRIC (Liver: 1.34 ± 0.12 vs. 0.97 ± 0.20 μmol/g, p = 0.04) and hepatocellular injury was reduced significantly (ALT: 2409 ± 447 vs. 6613 ± 1117 IU/L, p = 0.003). Systemic- and portal venous IL-6 and TNF-alpha levels were markedly lower following iRIC, demonstrating a reduced inflammatory response. iRIC led to a structural and functional preservation of the intestinal barrier. These results suggest that iRIC might confer a potent protection against the detrimental effects of THI in rats via reducing IRI and systemic inflammatory responses and at the same time by mitigating the dramatic consequences of severe intestinal congestion and bacterial translocation.

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.

Effects of terlipressin infusion during hepatobiliary surgery on systemic and splanchnic haemodynamics, renal function and blood loss: a double-blind, randomized clinical trial

Background

Terlipressin, in general, is a vasopressor which acts via V1 receptors. Its infusion elevates mean blood pressure and can reduce bleeding which has a splanchnic origin. The primary outcome was to assess the impact of intraoperative terlipressin infusion on portal venous pressure during hepatobiliary surgery; the 2ry outcomes included effects upon systemic hemodynamics, estimated blood loss, and postoperative renal functions.

Methods

This prospective randomized study involved 50 patients undergoing hepatobiliary surgery who were randomly and equally allocated into terlipressin group, or a control group. The terlipressin group received an initial bolus dose of (1 mg over 30 min) followed by a continuous infusion of 2 μg/kg/h throughout the procedure and gradually weaned over the first four postoperative hours, whereas the control group received the same volumes of normal saline. The portal venous pressure changes were measured directly through a portal vein angiocatheter.

Results

Portal pressure was significantly reduced over time in the terlipressin group only (from 17.88 ± 7.32 to 15.96 ± 6.55 mmHg, p < .001). Mean arterial blood pressure was significantly higher in the terlipressin group. Estimated blood loss was significantly higher in the control group than the terlipressin group (1065.7 ± 202 versus 842 ± 145.5 ml; p = 0.004), and the units of packed RBCs transfused were significantly higher in the control group ((0–2) versus (0–4) p = 0.003). There was no significant difference between groups as regards the incidence of acute kidney injury.

Conclusion

Intraoperative infusion of terlipressin during hepatobiliary surgery was shown to improve intraoperative portal hemodynamics with subsequent reduction in blood loss.

Trial registration

Clinical trial number and registry URL: Trial registration number: NCT02718599. Name of registry: ClinicalTrials.gov. URL of registry: https://clinicaltrials.gov/ct2/show/NCT02718599. Date of registration: March 2016. Date of enrolment of the first participant to the trial: April 2016.

Quantitative Measure of Intestinal Permeability Using Blue Food Coloring

BACKGROUND

Loss of intestinal barrier integrity plays a fundamental role in the pathogenesis of various gastrointestinal diseases and is implicated in the onset of sepsis and multiple organ failure. An array of methods to assess different aspects of intestinal barrier function suffers from lack of sensitivity, prolonged periods of specimen collection, or high expense. We have developed a technique to measure the concentration of the food dye FD&C Blue #1 from blood and sought to assess its utility in measuring intestinal barrier function in humans.

MATERIALS AND METHODS

Four healthy volunteers and 10 critically ill subjects in the intensive care unit were recruited in accordance with an institutional review board approved protocol. Subjects were given 0.5 mg/kg Blue #1 enterally as an aqueous solution of diluted food coloring. Five blood specimens were drawn per subject: 0 h (before dose), 1, 2, 4, and 8 h. After plasma isolation, organic extracts were analyzed by high-performance liquid chromatography/mass spectrometry detecting the presence of unmodified dye.

RESULTS

We found no baseline detectable absorption in healthy volunteers. After including the subjects in the intensive care unit, we compared dye absorption in the six subjects who met criteria for septic shock with the eight who did not. Septic patients demonstrated significantly greater absorption of Blue #1 after 2 h.

CONCLUSIONS

We have developed a novel, easy-to-use method to measure intestinal barrier integrity using a food grade dye detectable by mass spectrometry analysis of patient blood following oral administration.

Liver function assessment by indocyanine green plasma disappearance rate in patients with intra-abdominal hypertension after "non-hepatic" abdominal surgery

BACKGROUND AND OBJECTIVE

Liver function assessment in patients with intra-abdominal hypertension (IAH) after major abdominal surgery is complex and often confounding. Elevated intra-abdominal pressure (IAP) often occurs after major abdominal surgery, and is associated with decreased abdominal blood flow and organ dysfunction, and it could cause abdominal compartment syndrome (ACS), which is a life-threatening condition. Plasma disappearance rate (PDR) of indocyanine green (ICG) and ICG retention rate after 15 min (R15) were used to evaluate liver function and as a prognostic parameter after major abdominal surgery.

METHODS

In this prospective/observational study, 51 patients were followed in the surgical intensive care unit after major abdominal surgery (operation of the small and large intestine, stomach, pancreas, spleen, or resection of the abdominal aorta), 29 had IAH. The PDR-ICG and R15 were analyzed 24 h after surgery concurrently with IAP, APP, bilirubin, AST, ALT, prothrombin time, albumin, cardiac index, arterial lactate, oxygen delivery, MAP (mean arterial pressure), APACHE II (acute physiology and chronic health evaluation), SOFA (sequential organ failure assessment), and SAPS II (simplified acute physiology score). IAH has been defined as a peak intra-abdominal pressure (IAP) value of ≥12 mmHg, at a minimum, as two standardized measurements obtained 1-6 h apart.

RESULTS

The PDR-ICG measured 24 h after surgery was not different among groups (20.95% [SD = 10.34] vs 25.40% [SD = 7.42]), p = .094. ICG R15 was significantly higher in patients with IAH, 11.10% [SD = 13.82] vs 8.30 [SD = 11.46], p < .05, respectively. The PDR/ICG value was significantly lower in non-survivors than survivors (16.82 [SD = 10.87] vs 24.35 [SD = 8.48], p < .05).

CONCLUSIONS

The results suggest that PDR/ICG and ICG R15 are useful dynamic tests for evaluation of complex liver function and survival prediction after major abdominal surgery in patients with IAH.

Reduction of venous pressure during the resection of liver metastases compromises enteric blood flow: IGFBP-1 as a novel biomarker of intestinal barrier injury

OBJECTIVES

Disruption of the intestinal barrier and bacterial translocation commonly occur when intestinal blood flow is compromised. The aim of this study was to determine whether liver resection induces intestinal damage.

METHODS

We investigated intestinal fatty-acid binding protein and insulin-like growth factor binding protein levels in the plasma of patients who underwent liver resection.

RESULTS

We show that liver resection is associated with significant intestinal barrier injury, even if the Pringle maneuver is not performed.

CONCLUSION

We propose the use of insulin-like growth factor binding protein-1 as a novel biomarker of intestinal damage in such situations.

Intestinal permeability changes, systemic endotoxemia, inflammatory serum markers and sepsis after Whipple's operation for carcinoma of the pancreas head

POURPOSE

The aim was to evaluate the relationship between failure of gut barrier function, inflammatory markers and septic complications after pancreatoduodenectomy for pancreatic adenocarcinoma.

METHODOLOGY

44 patients were enrolled in this prospective observational clinical study and underwent curative open pancreatoduodenectomy for adenocarcinoma of the head of the pancreas. All patients underwent assessment of intestinal permeability using the lactulose/manitol excretions ratios (L/M ratio), endotoxemia, IL-1β, IL-6, CRP, and elastase levels before surgery and on postoperative days 1, 3 and 7. Septic complication was defined as a specific clinical condition related to infection by bacterium, virus, or fungus in a specific organ/compartment with positive culture.

RESULTS

Septic complications developed in 25% of patients. There were no significant differences in preoperative L/M ratio, endotoxine, CRP, IL-1β, IL-6, and elastase levels between sepsis-positive and sepsis-negative groups. All patients showed a significant increase in intestinal permeability, endotoxemia, IL-1, IL-6, CRP and elastase on the first postoperative day. At postoperative day 7, the sepsis-positive group continued to demonstrate an increase in intestinal permeability, endotoxemia and elastase; a significant difference was observed between the two groups (P = 0.02), whereas there was no significant difference in IL-1, IL-6, and CRP levels.

CONCLUSION

The pattern of change of intestinal permeability, systemic endotoxemia, and elastase concentration in the postoperative period is significantly higher in patients in whom sepsis develops, while the concentration of IL-1β, IL-6 and CRP do not permit to distinguish infection from inflammation.

Intraoperative Goal-directed Fluid Therapy in Elective Major Abdominal Surgery: A Meta-analysis of Randomized Controlled Trials

Objectives:

To compare the effects of intraoperative goal-directed fluid therapy (GDFT) with conventional fluid therapy, and determine whether there was a difference in outcome between studies that did and did not use Enhanced Recovery After Surgery (ERAS) protocols.

Methods:

Meta-analysis of randomized controlled trials of adult patients undergoing elective major abdominal surgery comparing intraoperative GDFT versus conventional fluid therapy. The outcome measures were postoperative morbidity, length of stay, gastrointestinal function and 30-day mortality.

Results:

A total of 23 studies were included with 2099 patients: 1040 who underwent GDFT and 1059 who received conventional fluid therapy. GDFT was associated with a significant reduction in morbidity (risk ratio [RR] 0.76, 95% confidence interval [CI] 0.66–0.89, P = 0.0007), hospital length of stay (LOS; mean difference −1.55 days, 95% CI −2.73 to −0.36, P = 0.01), intensive care LOS (mean difference −0.63 days, 95% CI −1.18 to −0.09, P = 0.02), and time to passage of feces (mean difference −0.90 days, 95% CI −1.48 to −0.32 days, P = 0.002). However, no difference was seen in mortality, return of flatus, or risk of paralytic ileus. If patients were managed in an ERAS pathway, the only significant reductions were in intensive care LOS (mean difference −0.63 days, 95% CI −0.94 to −0.32, P < 0.0001) and time to passage of feces (mean difference −1.09 days, 95% CI −2.03 to −0.15, P = 0.02). If managed in a traditional care setting, a significant reduction was seen in both overall morbidity (RR 0.69, 95% CI 0.57 to −0.84, P = 0.0002) and total hospital LOS (mean difference −2.14, 95% CI −4.15 to −0.13, P = 0.04).

Conclusions:

GDFT may not be of benefit to all elective patients undergoing major abdominal surgery, particularly those managed in an ERAS setting.

Increased adhesion of Plasmodium falciparum infected erythrocytes to ICAM-1 in children with acute intestinal injury

BACKGROUND

Children with severe malaria are at increased risk of invasive bacterial disease particularly infection with enteric gram-negative organisms. These organisms are likely to originate from the gut, however, how and why they breach the intestinal interface in the context of malaria infection remains unclear. One explanation is that accumulation of infected red blood cells (iRBCs) in the intestinal microvasculature contributes to tissue damage and subsequent microbial translocation which can be addressed through investigation of the impact of cytoadhesion in patients with malaria and intestinal damage.

METHODS

Using a static adhesion assay, cytoadhesion of iRBCs was quantified in 48 children with malaria to recombinant proteins constitutively expressed on endothelial cell surfaces. Cytoadhesive phenotypes between children with and without biochemical evidence of intestinal damage [defined as endotoxemia or elevated plasma intestinal fatty acid binding protein (I-FABP)] was compared.

RESULTS

The majority of parasites demonstrated binding to the endothelial receptors CD36 and to a lesser extent to ICAM-1. Reduced adhesion to CD36 but not adhesion to ICAM-1 or rosetting was associated with malarial anaemia (p = 0.004). Increased adhesion of iRBCs to ICAM-1 in children who had evidence of elevated I-FABP (p = 0.022), a marker of intestinal ischaemia was observed. There was no correlation between the presence of endotoxemia and increased adhesion to any of the recombinant proteins.

CONCLUSION

Increased parasite adhesion to ICAM-1 in children with evidence of intestinal ischaemia lends further evidence to a link between the cytoadherence of iRBCs in gut microvasculature and intestinal damage.

Variable Pringle Maneuvers and Effect on Intestinal Epithelium in Rats. A Pilot Experimental Study in Rats

BACKGROUND

It is observed that combined liver and colon surgery especially when this includes major liver resection with Pringle maneuver (PM) performance does not have a favorable outcome. Aim of our experimental study is to investigate the impact of portal triad occlusion on the large bowel and intra-abdominal inflammation and potent protective effects of the variants of (PM) in the combined surgical cases.

MATERIALS AND METHODS

Forty-four rats were divided into four groups. In group A (control group), 1cm of the left partial colon was resected and then an end-to-end anastomosis was performed. In group B, a continuous PM for 30 minutes was performed followed by resection of 1cm of the left colon and an end-to-end anastomosis. In group C, the left colonic resection and anastomosis was performed after intermittent PM (IPM), which was 10 minutes PM followed by 5 minutes reperfusion repeated for three circles. In group D, an ischemic preconditioning for 10 minutes was initially performed followed by 5 minutes reperfusion and then continuous PM for 30 minutes. Finally the rats in group D underwent a 1cm left colonic resection and an end-to-end anastomosis.

RESULTS

The percentage of colitis was higher in the B group (P = 0,19). The percentage of inflammation was not significantly higher even when we compared all "occlusion" groups (B+C+D) with the sham group. No evidence of pancreatitis was found in the sham group whereas amylase and lipase levels were higher in Groups B, C and D together (P = 0,0267). The comparison of group A to group B showed a significant difference (P = 0,0014) caused by continuous PM for 30 minutes, but there was no such result after IPM.

CONCLUSIONS

Major liver resections are performed with PM in order to minimize intra-operative blood loss. In the combined cases of colon surgery and major liver resections where PM is needed our results showed that IPM presents with better outcome and could be preferred compared with the other PM variants.

Intestinal ischemic preconditioning ameliorates hepatic ischemia/reperfusion injury in rats: role of heme oxygenase 1 in the second window of protection

Preconditioning by brief ischemia protects not only the concerned organ but also other distant organs against subsequent lethal damage; this is called remote ischemic preconditioning (RIPC). This study was designed to investigate the impact of intestinal RIPC on hepatic ischemia/reperfusion injury (IRI) with a special interest in heme oxygenase 1 (HO-1) induction in the second window of protection (SWOP). Male Wistar rats were randomly assigned to 1 of 2 groups: an RIPC group or a sham group. Before hepatic IRI, either intestinal RIPC, consisting of 2 cycles of 4-minute superior mesenteric artery clamping separated by 11 minutes of declamping (RIPC group), or a sham procedure (sham group) was performed. After 48 hours of recovery, the rats were exposed to 30 minutes of total hepatic IRI. Transaminase releases and proinflammatory cytokines were determined at several time points after reperfusion. Histopathological analysis and animal survival were also investigated. Intestinal RIPC significantly lowered transaminase release (alanine aminotransferase at 2 hours: 873.3 ± 176.4 IU/L for the RIPC group versus 3378.7 ± 871.1 IU/L for the sham group, P < .001) as well as proinflammatory cytokine production (tumor necrosis factor α at 2 hours: 930 ± 42 versus 387 ± 17 pg/μL, P < .001). The morphological integrity of the liver and the ileum was maintained significantly better with intestinal RIPC; this reached statistical significance not only in Suzuki's liver injury score (3.5 ± 0.2 versus 0.7 ± 0.5, P = .007) but also in Park's score for intestinal damage (4.0 ± 0.4 versus 2.0 ± 0.2, P = .007). Animal survival was also markedly improved (83.1% versus 15.4%, P < .001). As a mechanism underlying this protection, HO-1 was substantially induced in liver tissue, especially in hepatocytes, with remarkable up-regulation of bradykinin in the portal blood, whereas HO-1 protein induction in enterocytes was not significant. In conclusion, intestinal RIPC remarkably attenuates hepatic IRI in the SWOP, presumably by HO-1 induction in hepatocytes.

Novel multi-sugar assay for site-specific gastrointestinal permeability analysis: a randomized controlled crossover trial

BACKGROUND & AIMS

Increased gastrointestinal (GI) permeability is an important hallmark of many conditions, potentially leading to antigen exposure and sepsis. Current permeability tests are hampered by analytical limitations. This study aims to compare the accuracy of our multi-sugar (MS) and the classical dual sugar (DS) test for detection of increased GI permeability.

METHODS

Ten volunteers received permeability analysis using MS (1 g sucrose, lactulose, sucralose, erythritol, 0.5 g rhamnose in water) or DS (5 g lactulose, 0.5 g rhamnose), after indomethacin or placebo. Blood and urine were analyzed by isocratic LC-MS.

RESULTS

MS testing revealed significantly elevated urinary lactulose/rhamnose (L/R) ratios after indomethacin, due to enhanced lactulose excretion (P < .01) and unaltered rhamnose excretion. The DS test showed increased L/R ratios, due to increased lactulose excretion and decreased rhamnose excretion (both P < .05). After indomethacin, plasma L/R increased in both assays (P < .05 and P < .01). Urinary and plasma L/R ratios correlated significantly. Indomethacin increased sucrose excretion and 0-1 h sucrose/rhamnose. Colon permeability was unchanged.

CONCLUSIONS

Sensitive permeability analysis is feasible in plasma and urine using MS or DS test. In contrast to the DS test, monosaccharide excretion is not decreased by the MS test. In short, the MS test provides accurate, site-specific information on gastroduodenal, small, and large intestinal permeability. Registered at US National Library of Medicine (http://www.clinicaltrials.gov, NCT00943345).

Probiotics in the intensive care unit

Probiotics are living microorganisms that, when ingested in adequate amounts, provide benefits to the host. The benefits include either a shortened duration of infections or decreased susceptibility to pathogens. Proposed mechanisms of beneficial effects include improving gastrointestinal barrier function, modification of the gut flora by inducing host cell antimicrobial peptides and/or local release of probiotic antimicrobial factors, competition for epithelial adherence, and immunomodulation. With increasing intensive care unit (ICU) antibacterial resistance rates and fewer new antibiotics in the research pipeline, focus has been shifted to non-antibiotic approaches for the prevention and treatment of nosocomial infections. Probiotics offer promise to ICU patients for the prevention of antibiotic-associated diarrhea, Clostridium difficile infections, multiple organ dysfunction syndrome, and ventilator-associated pneumonia. Our current understanding of probiotics is confounded by inconsistency in probiotic strains studied, optimal dosages, study durations, and suboptimal sample sizes. Although probiotics are generally safe in the critically ill, adverse event monitoring must be rigorous in these vulnerable patients. Delineation of clinical differences of various effective probiotic strains, their mechanisms of action, and optimal dosing regimens will better establish the role of probiotics in various disorders. However, probiotic research will likely be hindered in the future given a recent ruling by the U.S. Food and Drug Administration.

Mucosal tonometry as early warning of gastrojejunal leak in laparoscopic Roux-en-y gastric bypass

The laparoscopic Roux-en-Y gastric bypass (LRYGB) is the standard surgical procedure for morbidly obese patients in many centers worldwide. The gastrojejunal anastomosis (GJA) leak has a 2 % incidence and a 10 % mortality. This prospective study aims to test gastroenteric tonometry as an early warning of GJA leak risk. A nasogastric tube with tonometric capability was used to monitor gastroenteric mucosal carbon dioxide partial pressure (PgeCO2) in 32 consecutive patients during the first 24 to 72 postoperative hours after LRYGB. Sensitivity was 100 %, specificity 96.77 %, likelihood ratio 31, and area under receiver operating characteristic curve 0.984. The only early gastrojejunal leak occurred to the patient with maximal PgeCO2 (13.9 kPa) of the cohort. The remaining patients kept a PgeCO2 below 11 kPa except one; none of these developed early GJA leak. Mucosal gastroenteric tonometry may be a useful predictor of early GJA leak of the LRYGB.

Total intermittent Pringle maneuver during liver resection can induce intestinal epithelial cell damage and endotoxemia

OBJECTIVES

The intermittent Pringle maneuver (IPM) is frequently applied to minimize blood loss during liver transection. Clamping the hepatoduodenal ligament blocks the hepatic inflow, which leads to a non circulating (hepato)splanchnic outflow. Also, IPM blocks the mesenteric venous drainage (as well as the splenic drainage) with raising pressure in the microvascular network of the intestinal structures. It is unknown whether the IPM is harmful to the gut. The aim was to investigate intestinal epithelial cell damage reflected by circulating intestinal fatty acid binding protein levels (I-FABP) in patients undergoing liver resection with IPM.

METHODS

Patients who underwent liver surgery received total IPM (total-IPM) or selective IPM (sel-IPM). A selective IPM was performed by selectively clamping the right portal pedicle. Patients without IPM served as controls (no-IPM). Arterial blood samples were taken immediately after incision, ischemia and reperfusion of the liver, transection, 8 hours after start of surgery and on the first post-operative day.

RESULTS

24 patients (13 males) were included. 7 patients received cycles of 15 minutes and 5 patients received cycles of 30 minutes of hepatic inflow occlusion. 6 patients received cycles of 15 minutes selective hepatic occlusion and 6 patients underwent surgery without inflow occlusion. Application of total-IPM resulted in a significant increase in I-FABP 8 hours after start of surgery compared to baseline (p<0.005). In the no-IPM group and sel-IPM group no significant increase in I-FABP at any time point compared to baseline was observed.

CONCLUSION

Total-IPM in patients undergoing liver resection is associated with a substantial increase in arterial I-FABP, pointing to intestinal epithelial injury during liver surgery.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01099475.

Admission levels of soluble CD137 are increased in patients with acute pancreatitis and are associated with subsequent complications

The progression of acute pancreatitis to necrotizing pancreatitis which often results in high morbidity and mortality is difficult to predict. Here we report that serum concentrations of sCD137 are increased in patients with acute pancreatitis. Admission levels and 10-day median sCD137 levels positively correlate with markers of biliary pancreatitis and the 10-day sCD137 median is significantly higher in metabolic than in alcoholic pancreatitis. Serum concentrations of sCD137 at time of admission and the 10-day median of sCD137 correlate with the Ranson and APACHE II disease scores but not with the radiological Balthazar and Schroeder scores that reflect pancreatic and peripancreatic necrosis. Further, sCD137 levels correlate with the probability of complications and lethality. The association of sCD137, a product of activated T cells, with the severity of acute pancreatitis suggests that T cells contribute to the pathogenesis of acute pancreatitis.

Increased skin autofluorescence after colorectal operation reflects surgical stress and postoperative outcome

BACKGROUND

Abdominal surgery is a major oxidative stress effector. The increase in oxidative stress has been related to postoperative complications. Oxidative stress leads to the formation and accumulation of oxidation protein end products, which exhibit autofluorescence (AF) and induce inflammatory reactions.

METHODS

Skin AF was assessed perioperatively in 40 consecutive colorectal surgery patients until discharge. Duration of surgery, estimated blood loss, and urinary production per hour were analyzed as measures of surgical stress. The clinical occurrence of anastomotic leakage, systemic infections, and cardiopulmonary complications within 30 days of surgery were analyzed.

RESULTS

A perioperative increase in skin AF of 19 ± .2% was observed. Duration of operation and blood loss were independently associated with the perioperative increase in skin AF. Skin AF correlated with C-reactive protein levels postoperatively. American Society of Anesthesiologists classification, duration of operation, and preoperative and perioperative increases in AF were independently associated with postoperative complications.

CONCLUSIONS

This is the first study to demonstrate an association between skin AF and surgical stress and outcomes, which may rate the condition of a patient after operation.

Exercise-induced splanchnic hypoperfusion results in gut dysfunction in healthy men

Background

Splanchnic hypoperfusion is common in various pathophysiological conditions and often considered to lead to gut dysfunction. While it is known that physiological situations such as physical exercise also result in splanchnic hypoperfusion, the consequences of flow redistribution at the expense of abdominal organs remained to be determined. This study focuses on the effects of splanchnic hypoperfusion on the gut, and the relationship between hypoperfusion, intestinal injury and permeability during physical exercise in healthy men.

Methods and Findings

Healthy men cycled for 60 minutes at 70% of maximum workload capacity. Splanchnic hypoperfusion was assessed using gastric tonometry. Blood, sampled every 10 minutes, was analyzed for enterocyte damage parameters (intestinal fatty acid binding protein (I-FABP) and ileal bile acid binding protein (I-BABP)). Changes in intestinal permeability were assessed using sugar probes. Furthermore, liver and renal parameters were assessed. Splanchnic perfusion rapidly decreased during exercise, reflected by increased gap_g-apCO₂ from −0.85±0.15 to 0.85±0.42 kPa (p<0.001). Hypoperfusion increased plasma I-FABP (615±118 vs. 309±46 pg/ml, p<0.001) and I-BABP (14.30±2.20 vs. 5.06±1.27 ng/ml, p<0.001), and hypoperfusion correlated significantly with this small intestinal damage (r_S = 0.59; p<0.001). Last of all, plasma analysis revealed an increase in small intestinal permeability after exercise (p<0.001), which correlated with intestinal injury (r_S = 0.50; p<0.001). Liver parameters, but not renal parameters were elevated.

Conclusions

Exercise-induced splanchnic hypoperfusion results in quantifiable small intestinal injury. Importantly, the extent of intestinal injury correlates with transiently increased small intestinal permeability, indicating gut barrier dysfunction in healthy individuals. These physiological observations increase our knowledge of splanchnic hypoperfusion sequelae, and may help to understand and prevent these phenomena in patients.

Haemodynamic goal-directed therapy and postoperative infections: earlier is better. A systematic review and meta-analysis

Introduction

Infectious complications are the main causes of postoperative morbidity. The early timing of their promoting factors is the rationale for perioperative strategies attempting to reduce them. Our aim was to determine the effects of perioperative haemodynamic goal-directed therapy on postoperative infection rates.

Methods

We performed a systematic review and meta-analysis. MEDLINE, EMBASE, The Cochrane Library and the DARE databases were searched up to March 2011. Randomised, controlled trials of major surgery in adult patients managed with perioperative goal-directed therapy or according to routine haemodynamic practice were included. Primary outcome measure was specific type of infection.

Results

Twenty-six randomised, controlled trials with a combined total of 4,188 participants met our inclusion criteria. Perioperative goal-directed therapy significantly reduced surgical site infections (pooled OR 0.58, 95% CI 0.46 to 0.74; P < 0.0001), pneumonia (pooled OR 0.71, 95% CI 0.55 to 0.92; P = 0.009), and urinary tract infections (pooled OR 0.44, 95% CI 0.22 to 0.84; P = 0.02). A significant benefit was found regarding total infectious episodes (OR 0.40, 95% CI 0.28 to 0.58; P < 0.00001).

Conclusions

Flow-directed haemodynamic therapy designed to optimise oxygen delivery protects surgical patients against postoperative hospital-acquired infections and must be strongly encouraged, particularly in the high-risk surgical population.

The enteric nervous system as a regulator of intestinal epithelial barrier function in health and disease

The intestinal epithelia proliferate and differentiate along the crypt villus axis to constitute a barrier cell layer separating some 10¹³ potentially harmful bacteria from a sterile mucosal compartment. Strict regulatory mechanisms are required to maintain a balance between the appropriate uptake of luminal food components and proteins, while constraining the exposure of the mucosal compartment to luminal antigens and microbes. The enteric nervous system is increasingly recognized as such a regulatory housekeeper of the epithelial barrier integrity, in addition to its ascribed immunomodulatory potential. Inflammation affects both epithelial integrity and barrier function and, in turn, loss of barrier function perpetuates inflammatory conditions. The observation that inflammatory conditions affect enteric neurons may add to the dysregulated barrier function in chronic disease. Here, we review the current understanding of the regulatory role of the nervous system in the maintenance of barrier function in healthy state, or during pathological conditions of, for instance, stress-induced colitis, surgical trauma or inflammation. We will discuss the clinical potential for advances in understanding the role of the enteric nervous system in this important phenomenon.

Non-invasive assessment of barrier integrity and function of the human gut

Over the past decades evidence has been accumulating that intestinal barrier integrity loss plays a key role in the development and perpetuation of a variety of disease states including inflammatory bowel disease and celiac disease, and is a key player in the onset of sepsis and multiple organ failure in situations of intestinal hypoperfusion, including trauma and major surgery. Insight into gut barrier integrity and function loss is important to improve our knowledge on disease etiology and pathophysiology and contributes to early detection and/or secondary prevention of disease. A variety of tests have been developed to assess intestinal epithelial cell damage, intestinal tight junction status and consequences of intestinal barrier integrity loss, i.e. increased intestinal permeability. This review discusses currently available methods for evaluating loss of human intestinal barrier integrity and function.

Retroperitoneal approach to abdominal aortic aneurysm repair preserves splanchnic perfusion as measured by gastric tonometry

BACKGROUND

We investigated if minimizing bowel manipulation and mesenteric traction using the retroperitoneal approach in open abdominal aortic aneurysm (AAA) repair preserves splanchnic perfusion, as measured by gastric tonometry, and reduces the systemic inflammatory response and dysfunction of the various organs.

METHODS

Patients undergoing elective AAA repair were randomized into three groups. Group I had repair via the retroperitoneal approach, while groups II and III were repaired via the transperitoneal approach with the bowel packed within the peritoneal cavity or exteriorized in a bowel bag, respectively. A tonometer was used to measure gastric intramucosal pH (pHi), as an indicator of splanchnic perfusion, just prior to aortic clamping, during clamping, and at 0.5, 1, 2, 4, 6, and 12 hr after clamp release. Multiorgan dysfunction syndrome (MODS) and systemic inflammatory response syndrome (SIRS) scores were calculated and systemic interleukins (IL-6 and IL-10) measured at predetermined intervals.

RESULTS

Thirty-four patients were successfully randomized. The gastric pHi was significantly lower in group II (n=12) and group III (n=11) compared to group I (n=11) during aortic clamping and immediately after clamp release (p<0.05). The aortic clamp time, blood loss, MODS and SIRS scores, and systemic cytokine response were similar in all three groups. When the three groups were combined, there were significant positive correlations between the operation time, aortic clamp time, and amount of blood lost and transfused with plasma IL-6 levels and MODS score on the first postoperative day.

CONCLUSION

The retroperitoneal approach for open AAA repair is associated with gastric tonometric evidence of better splanchnic perfusion compared to the transperitoneal approach.

Retroperitoneal repair of abdominal aortic aneurysm reduces bowel dysfunction

OBJECTIVE

To assess the effect of intestinal manipulation and mesenteric traction on gastro-intestinal function and postoperative recovery in patients undergoing abdominal aortic aneurysm (AAA) repair.

METHODS

Thirty-five patients undergoing AAA repair were randomised into 3 groups. Group I (n = 11) had repair via retroperitoneal approach while Group II (n = 12) and Group III (n = 12) were repaired via transperitoneal approach with bowel packed within the peritoneal cavity or exteriorised in a bowel bag respectively. Gastric emptying was measured pre-operatively (day 0), day 1 and day 3 using paracetamol absorption test (PAT) and area under curve (P(AUC)) was calculated. Intestinal permeability was measured using the Lactulose-Mannitol test.

RESULTS

Aneurysm size, operation time and PAT (on day 0 and day 3) were similar in the three groups. On day 1, the P(AUC) was significantly higher in Group I, when compared with Group II and Group III (P = .02). Resumption of diet was also significantly earlier in Group I as compared to Group II and Group III. The intestinal permeability was significantly increased in Group II and Group III at day 1 when compared with day 0, with no significant increase in Group I. Retroperitoneal repair was also associated with significantly shorter intensive care unit (P = .04) and hospital stay (P = .047), when compared with the combined transperitoneal repair group (Group II and III).

CONCLUSION

Retroperitoneal AAA repair minimises intestinal dysfunction and may lead to quicker patient recovery when compared to transperitoneal repair.

New Insight in Loss of Gut Barrier during Major Non-Abdominal Surgery

Background

Gut barrier loss has been implicated as a critical event in the occurrence of postoperative complications. We aimed to study the development of gut barrier loss in patients undergoing major non-abdominal surgery.

Methodology/Principal Findings

Twenty consecutive children undergoing spinal fusion surgery were included. This kind of surgery is characterized by long operation time, significant blood loss, prolonged systemic hypotension, without directly leading to compromise of the intestines by intestinal manipulation or use of extracorporeal circulation. Blood was collected preoperatively, every two hours during surgery and 2, 4, 15 and 24 hours postoperatively. Gut mucosal barrier was assessed by plasma markers for enterocyte damage (I-FABP, I-BABP) and urinary presence of tight junction protein claudin-3. Intestinal mucosal perfusion was measured by gastric tonometry (P_rCO₂, P_r-aCO₂-gap). Plasma concentration of I-FABP, I-BABP and urinary expression of claudin-3 increased rapidly and significantly after the onset of surgery in most children. Postoperatively, all markers decreased promptly towards baseline values together with normalisation of MAP. Plasma levels of I-FABP, I-BABP were significantly negatively correlated with MAP at ½ hour before blood sampling (−0.726 (p<0.001), −0.483 (P<0.001), respectively). Furthermore, circulating I-FABP correlated with gastric mucosal P_rCO₂, P_r-aCO₂-gap measured at the same time points (0.553 (p = 0.040), 0.585 (p = 0.028), respectively).

Conclusions/Significance

This study shows the development of gut barrier loss in children undergoing major non-abdominal surgery, which is related to preceding hypotension and mesenterial hypoperfusion. These data shed new light on the potential role of peroperative circulatory perturbation and intestinal barrier loss.

Significant immunomodulatory effects of Pseudomonas aeruginosa quorum-sensing signal molecules: possible link in human sepsis

Pathogenic bacteria use quorum-sensing signal molecules to co-ordinate the expression of virulence genes. Animal-based studies have demonstrated the immunomodulatory effects of quorum-sensing signal molecules. In the present study, we have examined the impact of these molecules on normal human immune function in vitro and compared this with immune changes in patients with sepsis where quorum-sensing signal molecules were detected in the sera of patients. Quorum-sensing signal molecules inhibited normal dendritic cell and T-cell activation and proliferation, and down-regulated the expression of co-stimulatory molecules on dendritic cells; in MLDCRs (mixed lymphocyte dendritic cell reactions), secretion of IL (interleukin)-4 and IL-10 was enhanced, but TNF-alpha (tumour necrosis factor-alpha), IFN-gamma (interferon-gamma) and IL-6 was reduced. Quorum-sensing signal molecules induced apoptosis in dendritic cells and CD4(+) cells, but not CD8(+) cells. Dendritic cells from patients with sepsis were depleted and ex vivo showed defective expression of co-stimulatory molecules and dysfunctional stimulation of allogeneic T-lymphocytes. Enhanced apoptosis of dendritic cells and differential CD4(+) Th1/Th2 (T-helper 1/2) cell apoptotic rate, and modified Th1/Th2 cell cytokine profiles in MLDCRs were also demonstrated in patients with sepsis. The pattern of immunological changes in patients with sepsis mirrors the effects of quorum-sensing signal molecules on responses of immune cells from normal individuals in vitro, suggesting that quorum-sensing signal molecules should be investigated further as a cause of immune dysfunction in sepsis.

The potential role for xanthine oxidase inhibition in major intra-abdominal surgery

BACKGROUND

Xanthine oxidase (XO) is a cytosolic metalloflavoprotein that has been implicated in the pathogenesis of a wide spectrum of diseases, and is thought to be the most important source of oxygen-free radicals and cell damage during re-oxygenation of hypoxic tissues. Clinical studies have already shown that XO inhibition is safe and effective for the treatment of gout, tumour-lysis syndrome, and to reduce complications such as post-operative arrhythmias, myocardial infarction and mortality in cardiovascular surgery. Here, we review the evidence from two decades of animal studies that have investigated the effects of XO inhibition during intra-abdominal surgery.

MATERIALS AND METHODS

A search of the Ovid MEDLINE database from 1950 through January 2007 was carried out using the following search terms: xanthine oxidase, allopurinol, ischemia, reperfusion, intestine, bowel, and general surgery.

RESULTS

The inhibition of XO has been shown to reduce oxidative stress, neutrophil priming, damage to intestinal mucosa due to ischemia reperfusion injuries, intestinal anastomotic dehiscence, bacterial translocation, adhesion formation, distant organ injury and mortality.

CONCLUSIONS

Despite this evidence which very strongly suggests a likely clinically beneficial role for XO inhibition in the elective and acute operative setting, it is surprising that such an approach has not been investigated in general surgery. There is now sufficient evidence to justify dedicated studies to determine the clinical benefits, dosing and duration of XO inhibition before and after gastrointestinal surgery.

Mixed endothelin receptor antagonism with tezosentan improves intestinal microcirculation in endotoxemic shock

BACKGROUND

Microcirculatory dysfunction is a common feature of sepsis. The potent vasoconstrictor endothelin (ET) is released in sepsis and endotoxemia, potentially contributing to sepsis-induced microcirculatory failure. In this study we tested the hypothesis that mixed ET receptor antagonism with tezosentan would improve splanchnic microcirculatory blood flow in acute porcine endotoxemia.

MATERIALS AND METHODS

Sixteen anesthetized and mechanically ventilated pigs received an infusion of endotoxin for 300 min. After 120 min eight pigs received a bolus dose of tezosentan 1 mg/kg followed by an infusion of tezosentan of 1 mg/kg/h throughout the experiment. Eight pigs served as endotoxin controls. Laser Doppler flowmetry was used to measure microcirculatory blood flow in the liver and in the ileal and colon mucosa. PCO(2) in the ileal mucosa was measured by air tonometry and portal vein flow by an ultrasonic flow probe.

RESULTS

Endotoxin administration induced a state of shock with impaired splanchnic microcirculatory blood flow. Microcirculation in the mucosa of the colon and ileum and mucosal-arterial PCO(2) gap were improved by tezosentan. Portal vein flow was increased, but hepatic microcirculatory blood flow was not significantly improved. Tezosentan preserved cardiac index and decreased pulmonary capillary wedge pressure compared to controls, without causing any differences in the heart rate or mean arterial blood pressure response. Tezosentan also distinctly improved pH and arterial lactate values.

CONCLUSIONS

The findings of this study indicate that ET is involved in the microcirculatory dysfunction seen in the ileal and colon mucosa in early endotoxemia. Moreover, this detrimental effect was counteracted by i.v. administration of the mixed ET receptor antagonist tezosentan.

EVIDENCE FOR INTESTINAL AND LIVER EPITHELIAL CELL INJURY IN THE EARLY PHASE OF SEPSIS

The development of sepsis and multiple organ failure are important determinants of the outcome in critically ill patients. Hepatosplanchnic hypoperfusion and resulting intestinal and hepatic cell damage have been implicated as central events in the development of sepsis and multiple organ failure. Our aim was to study (1) the relation between intramucosal perfusion and intestinal and hepatic cell damage in an early phase of sepsis and (2) the correlation of these parameters with mortality. Two groups of patients were consecutively selected after intensive care unit admission: patients with postoperative abdominal sepsis (n = 19) and patients with pneumonia-induced sepsis (n = 9). Intramucosal perfusion was assessed by gastric tonometry (Pr-aCO2 gap, Pico2). Circulating levels of intestinal fatty acid binding protein (I-FABP) and liver (L)-FABP were used as markers for intestinal and hepatic cellular damage, respectively. Outcome was determined on day 28. Pr-aCO2 gap correlated with I-FABP (Pearson r = 0.56; P < 0.001) in all patients, and gastric mucosal Pico2 correlated significantly with I-FABP (r = 0.57; P = 0.001) in patients with abdominal sepsis. At intensive care unit admission, nonsurvivors had significantly higher I-FABP and L-FABP values than survivors (I-FABP: 325 vs. 76 pg/mL, P < 0.04; L-FABP: 104 vs. 31 ng/mL, P < 0.04). Patients with abdominal sepsis was especially responsible for high-admission I-FABP and L-FABP levels in nonsurvivors (I-FABP: 405 vs. 85 pg/mL, P < 0.04; L-FABP: 121 vs. 59 ng/mL, P < 0.04). This study shows that splanchnic hypoperfusion correlates with intestinal mucosal damage, and that elevated plasma levels of I-FABP and L-FABP are associated with a poor outcome in critically ill patients with abdominal sepsis.

Severe acute pancreatitis: Clinical course and management

Severe acute pancreatitis (SAP) develops in about 25% of patients with acute pancreatitis (AP). Severity of AP is linked to the presence of systemic organ dysfunctions and/or necrotizing pancreatitis pathomorphologically. Risk factors determining independently the outcome of SAP are early multi-organ failure, infection of necrosis and extended necrosis (>50%). Up to one third of patients with necrotizing pancreatitis develop in the late course infection of necroses. Morbidity of SAP is biphasic, in the first week strongly related to early and persistence of organ or multi-organ dysfunction. Clinical sepsis caused by infected necrosis leading to multi-organ failure syndrome (MOFS) occurs in the later course after the first week. To predict sepsis, MOFS or deaths in the first 48-72 h, the highest predictive accuracy has been objectified for procalcitonin and IL-8; the Sepsis-Related Organ Failure Assessment (SOFA)-score predicts the outcome in the first 48 h, and provides a daily assessment of treatment response with a high positive predictive value. Contrast-enhanced CT provides the highest diagnostic accuracy for necrotizing pancreatitis when performed after the first week of disease. Patients who suffer early organ dysfunctions or at risk of developing a severe disease require early intensive care treatment. Early vigorous intravenous fluid replacement is of foremost importance. The goal is to decrease the hematocrit or restore normal cardiocirculatory functions. Antibiotic prophylaxis has not been shown as an effective preventive treatment. Early enteral feeding is based on a high level of evidence, resulting in a reduction of local and systemic infection. Patients suffering infected necrosis causing clinical sepsis, pancreatic abscess or surgical acute abdomen are candidates for early intervention. Hospital mortality of SAP after interventional or surgical debridement has decreased in high volume centers to below 20%.

Severe acute pancreatitis: Clinical course and management

Severe acute pancreatitis (SAP) develops in about 25% of patients with acute pancreatitis (AP). Severity of AP is linked to the presence of systemic organ dysfunctions and/or necrotizing pancreatitis pathomorphologically. Risk factors determining independently the outcome of SAP are early multi-organ failure, infection of necrosis and extended necrosis (> 50%). Up to one third of patients with necrotizing pancreatitis develop in the late course infection of necroses. Morbidity of SAP is biphasic, in the first week strongly related to early and persistence of organ or multi-organ dysfunction. Clinical sepsis caused by infected necrosis leading to multi-organ failure syndrome (MOFS) occurs in the later course after the first week. To predict sepsis, MOFS or deaths in the first 48-72 h, the highest predictive accuracy has been objectified for procalcitonin and IL-8; the Sepsis-Related Organ Failure Assessment (SOFA)-score predicts the outcome in the first 48 h, and provides a daily assessment of treatment response with a high positive predictive value. Contrast-enhanced CT provides the highest diagnostic accuracy for necrotizing pancreatitis when performed after the first week of disease. Patients who suffer early organ dysfunctions or at risk of developing a severe disease require early intensive care treatment. Early vigorous intravenous fluid replacement is of foremost importance. The goal is to decrease the hematocrit or restore normal cardiocirculatory functions. Antibiotic prophylaxis has not been shown as an effective preventive treatment. Early enteral feeding is based on a high level of evidence, resulting in a reduction of local and systemic infection. Patients suffering infected necrosis causing clinical sepsis, pancreatic abscess or surgical acute abdomen are candidates for early intervention. Hospital mortality of SAP after interventional or surgical debridement has decreased in high volume centers to below 20%.

Silent celiac disease activated by pancreaticoduodenectomy

Diarrhea and weight loss are common after pancreaticoduodenectomy, and arise from varying etiologies. An uncommon but important cause for these symptoms is the postoperative activation of silent celiac disease. We sought to describe the clinical presentation, diagnosis, treatment, and follow-up of a series of patients with silent celiac disease unmasked after pancreaticoduodenectomy, and to summarize the existing case reports on this association. A search of the electronic medical record at our institution was performed cross-referencing terms associated with celiac disease and pancreaticoduodenectomy for the years 1976-2004. Cases were then reviewed to ensure that no signs or symptoms attributable to celiac disease were present preoperatively. Seven patients were identified; five were male, and the median age was 56. All patients underwent surgery for a presumed pancreatic or ampullary malignancy. Six patients developed symptoms ultimately attributable to celiac disease immediately after pancreaticoduodenectomy, most commonly diarrhea and weight loss. A single patient had silent celiac disease incidentally diagnosed at pancreaticoduodenectomy that remained silent postoperatively on an unrestricted diet. Symptoms completely resolved in 4 of 6 patients after initiation of a gluten-free diet, with partial improvement in the remaining 2 patients. The median delay from pancreaticoduodenectomy to diagnosis of celiac disease in the 6 symptomatic patients was 6 months. Clinicians should consider celiac disease as a potential diagnosis in patients with failure to thrive and diarrhea after pancreaticoduodenectomy. This entity is uncommon, but may be under-recognized. The underlying mechanism may relate to an increased antigenic load secondary to postsurgical changes in intestinal physiology.