Diagnostic accuracy of plasma biomarkers for intestinal ischaemia

A Prospective Study on Lactate Dehydrogenase Levels in Acute Intestinal Obstruction as a Marker of Bowel Gangrene

Background Intestinal obstruction continues to be one of the most common causes of emergencies presenting to the surgical department. A thorough clinical examination along with relevant investigations continue to be best modality for timely management and prompt decision-making in such cases. Objectives The aim of this study was to identify patients of intestinal obstruction with elevated levels of serum lactate dehydrogenase (LDH) and correlate elevated LDH levels with bowel viability. Materials and methods The study comprised 46 cases of intestinal obstruction and their serum LDH values measured prior to surgical intervention/first day of admission. The intra-operative bowel viability was noted and compared with LDH values obtained, and their correlation was studied along with other variables of the patient. Results In our study, it was found that a serum LDH level of >800 IU/L signified an abnormal bowel with increased risk of bowel gangrene, as indicated by a sensitivity of 75% and a specificity of 94%. Gangrenous bowel was found to be more associated with causes such as superior mesenteric artery/vein thrombosis, volvulus, and habits such as alcoholism and tobacco consumption. Elevated LDH levels, however, do not correlate with the length of the affected gangrenous bowel, with the duration of presentation of symptoms, or as a predictor of mortality. Conclusion Serum LDH can be used as a good predictor of gangrenous bowel in cases of intestinal obstruction.

D-dimer - a multifaceted molecule

D-dimer, a universally unique marker for fibrin degradation, is generated through the enzymatic interplay of thrombin, factor XIIIa, and plasmin. The emergence of D-dimer-containing fibrin molecules occurs in both intravascular and extravascular spaces during pivotal physiological processes like haemostasis, thrombosis, and tissue repair. Given the inherently physiological nature of fibrin formation and fibrinolysis, basal levels of D-dimer fragments are present in plasma. Beyond its role as a marker of routine physiological processes, aberrations in D-dimer levels are indicative of a spectrum of conditions, both non-pathological and pathological. The clinical utility of D-dimer has been firmly established, particularly in scenarios like venous thromboembolism (VTE), pulmonary embolism (PE), deep vein thrombosis (DVT), and disseminated intravascular coagulation (DIC). Additionally, recent applications have extended to assess the prognosis of COVID-19. While D-dimer is commonly associated with thrombotic conditions, its elevation is not confined to these conditions alone. Elevated D-dimer levels are observed across various diseases, where its significance extends beyond diagnostic indicators to prognostic implications.

Exploring D-Lactate as a Biomarker for Acute Intestinal Necrosis in 2958 Patients: A Prospective Cross-Sectional Study

BACKGROUND

Timely diagnosis of acute intestinal necrosis (AIN) is lifesaving, but challenging due to unclear clinical presentation. D-lactate has been proposed as an AIN biomarker.

OBJECTIVES

We aimed to test the diagnostic performance in a clinical setting.

METHODS

We performed a cross-sectional prospective study, including all adult patients with acute referral to a single tertiary gastrointestinal surgical department during 2015-2016 and supplemented by enrollment of high-risk in-hospital patients suspected of having AIN during 2016-2019. AIN was verified intraoperatively, and D-lactate was analyzed using an automatic spectrophotometric set-up. A D-lactate cut-off for AIN was estimated using the receiver operating characteristic curve. The performance according to patient subgroups was estimated using the area under the receiver operating characteristic curve (AUC). Given the exploratory nature of this study, a formal power calculation was not feasible.

RESULTS

Forty-four AIN patients and 2914 controls were enrolled. The D-lactate cut-off was found to be 0.0925 mM. Due to lipemic interference, D-lactate could not be quantified in half of the patients, leaving 23 AIN patients and 1456 controls for analysis. The AUC for the diagnosis of AIN by D-lactate was 0.588 (95% confidence interval 0.475-0.712), with a sensitivity of 0.261 and specificity of 0.892. Analysis of high-risk patients showed similar results (AUC 0.579; 95% confidence interval 0.422-0.736).

CONCLUSION

D-lactate showed low sensitivity for AIN in both average-risk and high-risk patients. Moreover, lipemic interference precluded valid spectrophotometric assessment of D-lactate in half of the patients, further disqualifying the clinical utility of D-lactate as a diagnostic marker for AIN.

The Efficiency of Serum Biomarkers in Predicting the Clinical Outcome of Patients with Mesenteric Ischemia during Follow-Up: A Systematic Review

The initial clinical manifestation of acute mesenteric ischemia poses a diagnostic challenge, often leading to delays in identification and subsequent surgical intervention, contributing to adverse outcomes. Serum biomarkers, offering insights into the underlying pathophysiology, hold promise as prognostic indicators for acute mesenteric ischemia. This systematic review comprehensively explores the role of blood biomarkers in predicting clinical outcomes during follow-up for patients with mesenteric ischemia. A thorough literature search across the PubMed, Cochrane Library, and EMBASE databases yielded 33 relevant publications investigating the efficacy of serum biomarkers in predicting outcomes for mesenteric ischemia. Numerous studies underscore the utility of blood biomarkers in swiftly and accurately differentiating between causes of mesenteric ischemia, facilitating a prompt diagnosis. Elevated levels of specific biomarkers, particularly D-dimers, consistently correlate with heightened mortality risk and poorer clinical outcomes. While certain serum indicators exhibit substantial potential in associating with mesenteric ischemia, further research through rigorous human trials is imperative to enhance their consistent predictive ability during the follow-up period. This study underscores the diagnostic and prognostic significance of specific biomarkers for mesenteric ischemia, emphasizing the necessity for standardized procedures in future investigations.

Revascularization Strategies for Acute and Chronic Mesenteric Ischemia: A Narrative Review

Mesenteric ischemia is a challenging condition characterized by insufficient blood perfusion to the mesentery and, consequently, intestinal tissues that continues to perplex clinicians. Despite its low prevalence, the condition's variable clinical presentation and elusive radiographic diagnosis can delay life-saving interventions in the acute setting and deteriorate the quality of life of patients when left undiagnosed or misdiagnosed.

PURPOSE

Review and summarize recent diagnostic updates and emergent intervention strategies for acute and chronic mesenteric ischemia.

METHODS

A narrative review of all relevant studies from January 2022 through September 2023.

RESULTS

A total of 11 studies from MEDLINE, supplemented with 44 studies from Google Scholar, were included in the review.

CONCLUSIONS

Both acute and chronic mesenteric ischemia propose diagnostic and therapeutic challenges for interventionalists. Computed tomographic angiography remains the diagnostic modality of choice for both. Open surgical intervention remains the gold standard for acute mesenteric ischemia, while endovascular techniques are preferred for chronic mesenteric ischemia.

The Impact of Biomarkers on the Early Detection of Acute Mesenteric Ischemia

BACKGROUND

acute mesenteric ischemia (AMI) is a life-threatening condition that is caused by inadequate blood flow through the mesenteric vessel and is related to high mortality rates due to systemic complications. This study aims to systematically review the available literature concerning the major findings of possible biomarkers for early detection of acute mesenteric ischemia in the human population.

METHODS

studies that measured the performance of biomarkers during acute mesenteric ischemia were identified with the search of PubMed, Embase, Medline, and Cochrane library.

RESULTS

from a total of 654 articles, 46 articles examining 14 different biomarkers were filtered, falling within our inclusion criteria. Intestinal fatty acid-binding protein (I-FABP) was the most commonly researched biomarker regarding AMI, with sensitivity ranging from 61.5% to 100% and specificity ranging from 40% to 100%. The second most commonly researched biomarker was D-dimer, with a sensitivity of 60-100% and a specificity of 18-85.71%. L-lactate had a sensitivity of 36.6-90.91% and a specificity of 64.29-96%. Several parameters within the blood count were examined as potential markers for AMI, including NLR, PLR, MPV, RDW, DNI, and IG. Citrulline, interleukin 6 (IL-6), and procalcitonin (PCT) were the least-researched biomarkers.

CONCLUSION

different biomarkers showed different accuracies in detecting AMI. I-FABP and D-dimer have been the most researched and shown to be valuable in the diagnosis of AMI, whereas L-lactate could be used as an additional tool. Ischemia-modified albumin (IMA), alpha glutathione S-transferase (αGST), interleukin 6 (IL-6), and citrulline showed potential use in their respective studies. However, further research needs to be done on larger sample sizes and with controls to reduce bias. Several studies showed that neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), mean platelet volume (MPV), red-cell distribution width (RDW), delta neutrophil index (DNI), and immature granulocytes (IGs) might be useful, as well at the same time be widely distributed and affordable in combination with other markers presenting higher specificity and sensitivity.

Diagnostic accuracy of biomarkers to detect acute mesenteric ischaemia in adult patients: a systematic review and meta-analysis

BACKGROUND

Acute mesenteric ischaemia (AMI) is a disease with different pathophysiological mechanisms, leading to a life-threatening condition that is difficult to diagnose based solely on clinical signs. Despite widely acknowledged need for biomarkers in diagnosis of AMI, a broad systematic review on all studied biomarkers in different types of AMI is currently lacking. The aim of this study was to estimate the diagnostic accuracy of all potential biomarkers of AMI studied in humans.

METHODS

A systematic literature search in PubMed, The Cochrane Library, Web of Science and Scopus was conducted in December 2022. Studies assessing potential biomarkers of AMI in (at least 10) adult patients and reporting their diagnostic accuracy were included. Meta-analyses of biomarkers' sensitivity, specificity, and positive and negative likelihood ratios were conducted. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed, and the study quality was assessed with the QUADAS-2 tool.

RESULTS

Seventy-five studies including a total of 9914 patients assessed 18 different biomarkers in serum/plasma and one in urine (each reported in at least two studies), which were included in meta-analyses. None of the biomarkers reached a conclusive level for accurate prediction. The best predictive value overall (all studies with any type and stage of AMI pooled) was observed for Ischaemia-modified albumin (2 studies, sensitivity 94.7 and specificity 90.5), interleukin-6 (n = 4, 96.3 and 82.6), procalcitonin (n = 6, 80.1 and 86.7), and intestinal fatty acid-binding protein (I-FABP) measured in serum (n = 16, 73.9 and 90.5) or in urine (n = 4, 87.9 and 78.9). In assessment of transmural mesenteric ischaemia, urinary I-FABP (n = 2, 92.3 and 85.2) and D-dimer (n = 3, 87.6 and 83.6) showed moderate predictive value. Overall risk of bias was high, mainly because of selected study populations and unclear timings of the biomarker measurements after onset of symptoms. Combinations of biomarkers were rarely studied, not allowing meta-analyses.

CONCLUSIONS

None of the studied biomarkers had sufficient sensitivity and specificity to diagnose AMI, although some biomarkers showed moderate predictive accuracy. Future studies should focus on timing of measurements of biomarkers, distinguishing between early stage and transmural necrosis, and between different types of AMI. Additionally, studies on combinations of biomarkers are warranted. PROSPERO registration: CRD42022379341.

Antibiotic use in acute mesenteric ischemia: a review of the evidence and call to action

Acute mesenteric ischemia (AMI) is a life-threatening condition with a high mortality rate. The standard practice after making the diagnosis includes aggressive resuscitation, anticoagulation, followed by revascularization and resection of necrotic bowel. The role of empiric antibiotics in the management of AMI is not well defined in the literature. This review article aims to examine our current understanding on this matter, based on bench research and clinical studies. It is demonstrated in animal study model that the ischemia/reperfusion (I/R) injury damages intestinal epithelium, and subsequently lead to barrier dysfunction, a condition that can support bacterial translocation through a complex interplay between the intestinal epithelium, the intestinal immune system and the intestine's endogenous bacterial population. Based on this mechanism, it is possible that the use of antibiotics may help mitigate the consequences of I/R injury, which is examined in few animal studies. In clinical practice, many guidelines support the use of prophylactic antibiotics, based on a meta-analysis of randomized control trials (RCTs) demonstrating the benefit of antibiotics in multi-organ dysfunction syndrome. However, there is no direct reference to AMI in this meta-analysis. Most clinical studies that focus on AMI and mentions the use of antibiotics are retrospective and single institution, and very few comments on the role of antibiotics in their discussions. We conclude that there is limited evidence in literature to support the use of prophylactic antibiotic in AMI to improve outcome. More clinical studies with high level of evidence and basic science research are needed to improve our understanding on this topic and ultimately help build a better clinical pathway for patients with AMI.

Review article: Acute superior mesenteric vessel ischaemia: A review of clinical practice and biomarkers

A patient with acute occlusion of the superior mesenteric vessels resulting in superior mesenteric vessel ischaemia (SMVI) who presents to the ED with abdominal pain and unremarkable abdominal examination risks delay in diagnosis and treatment with adverse outcome. A comprehensive literature search was performed, and the evidence was reviewed. To-date, there are no accurate biomarkers of SMVI and so, heightened awareness among ED staff and rapidly actioning diagnostic imaging and surgical referral will help fast-track the patient with SMVI to surgical management. Management of SMVI is challenging and requires ongoing communication. Prompt surgical intervention may help reduce mortality and morbidity in SMVI. SMVI is associated with significant mortality and morbidity. With the lack of accurate biomarkers, diagnosis and management is challenging and requires heightened awareness among ED staff for prompt surgical referral and intervention.

Advances in the diagnosis of non-occlusive mesenteric ischemia and challenges in intra-abdominal sepsis patients: a narrative review

Non-occlusive mesenteric ischemia (NOMI) is a type of acute mesenteric ischemia (AMI) with a high mortality rate mainly because of a delayed or misdiagnosis. Intra-abdominal sepsis is one of the risk factors for developing NOMI, and its presence makes early diagnosis much more difficult. An increase in routine abdominal surgeries carries a corresponding risk of abdominal infection, which is a complication that should not be overlooked. It is critical that physicians are aware of the possibility for intestinal necrosis in abdominal sepsis patients due to the poor survival rate of NOMI. This review aims to summarize advances in the diagnosis of NOMI, and focuses on the diagnostic challenges of mesenteric ischemia in patients with intra-abdominal sepsis.

Incidence and outcomes of acute mesenteric ischaemia: a systematic review and meta-analysis

OBJECTIVE

To estimate the incidence of acute mesenteric ischaemia (AMI), proportions of its different forms and short-term and long-term mortality.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

MEDLINE (Ovid), Web of Science, Scopus and Cochrane Library were searched until 26 July 2022.

ELIGIBILITY CRITERIA

Studies reporting data on the incidence and outcomes of AMI in adult populations.

DATA EXTRACTION AND SYNTHESIS

Data extraction and quality assessment with modified Newcastle-Ottawa scale were performed using predeveloped standard forms. The outcomes were the incidence of AMI and its different forms in the general population and in patients admitted to hospital, and the mortality of AMI in its different forms.

RESULTS

From 3064 records, 335 full texts were reviewed and 163 included in the quantitative analysis. The mean incidence of AMI was 6.2 (95% CI 1.9 to 12.9) per 100 000 person years. On average 5.0 (95% CI 3.3 to 7.1) of 10 000 hospital admissions were due to AMI. Occlusive arterial AMI was the most common form constituting 68.6% (95% CI 63.7 to 73.2) of all AMI cases, with similar proportions of embolism and thrombosis.Overall short-term mortality (in-hospital or within 30 days) of AMI was 59.6% (95% CI 55.5 to 63.6), being 68.7% (95% CI 60.8 to 74.9) in patients treated before the year 2000 and 55.0% (95% CI 45.5 to 64.1) in patients treated from 2000 onwards (p<0.05). The mid/long-term mortality of AMI was 68.2% (95% CI 60.7 to 74.9). Mortality due to mesenteric venous thrombosis was 24.6% (95% CI 17.0 to 32.9) and of non-occlusive mesenteric ischaemia 58.4% (95% CI 48.6 to 67.7). The short-term mortality of revascularised occlusive arterial AMI was 33.9% (95% CI 30.7 to 37.4).

CONCLUSIONS

In adult patients, AMI is a rarely diagnosed condition with high mortality, although with improvement of treatment results over the last decades. Two thirds of AMI cases are of occlusive arterial origin with potential for better survival if revascularised.

PROSPERO REGISTRATION NUMBER

CRD42021247148.

Acute mesenteric ischemia: updated guidelines of the World Society of Emergency Surgery

Acute mesenteric ischemia (AMI) is a group of diseases characterized by an interruption of the blood supply to varying portions of the intestine, leading to ischemia and secondary inflammatory changes. If untreated, this process may progress to life-threatening intestinal necrosis. The incidence is low, estimated at 0.09-0.2% of all acute surgical admissions, but increases with age. Although the entity is an uncommon cause of abdominal pain, diligence is required because if untreated, mortality remains in the range of 50%. Early diagnosis and timely surgical intervention are the cornerstones of modern treatment to reduce the high mortality associated with this entity. The advent of endovascular approaches in parallel with modern imaging techniques is evolving and provides new treatment options. Lastly, a focused multidisciplinary approach based on early diagnosis and individualized treatment is essential. Thus, we believe that updated guidelines from World Society of Emergency Surgery are warranted, in order to provide the most recent and practical recommendations for diagnosis and treatment of AMI.

Sampling Thoracic Duct Lymph After Esophagectomy: A Pilot Study Investigating the "Gut-Lymph" Concept

Introduction: Gut-lymph in animal models of acute disease is altered by intestinal ischemia and contributes to the development of systemic inflammation and organ dysfunction. Investigating gut-lymph in humans is hampered difficulty in accessing the thoracic duct (TD) for lymph sampling. The aims of this study were to develop and pilot a technique of intraoperative TD cannulation with delayed embolization to serially measure TD lymph pressure, flow, and composition (including markers of intestinal injury) during the early postoperative period and in response to enteral feeding and vasopressor treatment. Methods: A Seldinger technique was used for percutaneous TD cannulation during an Ivor Lewis esophagogastrectomy. Lymph flow rate and pressure were measured. TD lymph and plasma were sampled at 12 hourly intervals for up to 120 hours after surgery and before TD embolization. Biochemistry, lipids, cytokines, and markers of intestinal injury were measured before and after enteral feeding commenced at 36 hours. Results: Intraoperative TD cannulation was technically feasible in three of four patients. Delayed TD embolization was only successful in one of three patients, with two patients requiring a re-thoracotomy to treat chylothorax. Profound changes in TD composition, but not flow rate, occurred over time and in response to enteral feeding and vasopressors. TD lymph compared with plasma had significantly higher lipase (1.4-17 × ), interleukin-6 (8-108 × ), tumor necrosis factor-α (2.7-17 × ), d-lactate (0.3-23 × ), endotoxin (0.1-41 × ), and intestinal fatty acid binding protein (1.1-853 × ). Conclusions: Although TD cannulation and lymph sampling were successful, TD embolization failed in two of three patients. The composition of sampled TD lymph changed dramatically in response to enteral feeding, indicating intestinal ischemia that could be exacerbated by nonselective vasopressors. The higher concentration of proinflammatory cytokines and gut injury markers in TD lymph, compared with plasma, lends support to the gut-lymph concept.

Accuracy of citrulline, I-FABP and D-lactate in the diagnosis of acute mesenteric ischemia

Early diagnosis of acute mesenteric ischemia (AMI) remains a clinical challenge, and no biomarker has been consistently validated. We aimed to assess the accuracy of three promising circulating biomarkers for diagnosing AMI-citrulline, intestinal fatty acid-binding protein (I-FABP), and D-lactate. A cross-sectional diagnostic study enrolled AMI patients admitted to the intestinal stroke center and controls with acute abdominal pain of another origin. We included 129 patients-50 AMI and 79 controls. Plasma citrulline concentrations were significantly lower in AMI patients compared to the controls [15.3 μmol/L (12.0-26.0) vs. 23.3 μmol/L (18.3-29.8), p = 0.001]. However, the area under the receiver operating curves (AUROC) for the diagnosis of AMI by Citrulline was low: 0.68 (95% confidence interval = 0.58-0.78). No statistical difference was found in plasma I-FABP and plasma D-lactate concentrations between the AMI and control groups, with an AUROC of 0.44, and 0.40, respectively. In this large cross-sectional study, citrulline, I-FABP, and D-lactate failed to differentiate patients with AMI from patients with acute abdominal pain of another origin. Further research should focus on the discovery of new biomarkers.

Ischemic bowel disease in 2021

Ischemic bowel disease (ISBODI) includes colon ischemia, acute mesenteric ischemia (AMI) and chronic mesenteric ischemia (CMI). Epidemiologically, colon ischemia is the most common type followed by AMI and CMI. There are various risk factors for the development of ISBODI. Abdominal pain is the common presenting symptom of each type. High clinical suspicion is essential in ordering appropriate tests. Imaging studies and colonoscopy with biopsy are the main diagnostic tests. Treatment varies from conservative measures to surgical resection and revascularization. Involvement of multidisciplinary team is essential in managing ISBODI. Although open surgery with revascularization plays an important role, recently there is an increasing interest in percutaneous endovascular treatment.

The role of citrulline, intestinal fatty acid-binding protein, and D-dimer as potential biomarkers in the diagnosis of internal herniation after Roux-en-Y gastric bypass

BACKGROUND

Diagnosing internal herniation (IH) in Roux-en-Y gastric bypass (RYGB) patients with acute abdominal pain poses a diagnostic challenge. Diagnostic laparoscopy is often required for a definitive diagnosis. We hypothesized that intestinal ischemia biomarkers would aid in the diagnosing of IH.

OBJECTIVES

To explore intestinal ischemia biomarkers in diagnosing IH.

SETTING

University Hospital, Sweden.

METHODS

Prospective inclusion of 46 RYGB patients admitted for acute abdominal pain between June 2015 and December 2017. Blood samples for analysis of citrulline, intestinal fatty acid-binding protein (I-FABP), and D-dimer were drawn <72 hours from admission and compared between patients with IH (n = 8), small bowel obstruction (SBO) (n = 5), other specified diagnoses (n = 12), or unspecified abdominal pain (n = 21). Levels of white blood cell count (WBC), C-reactive protein (CRP), and lactate at admission were compared. A prospective pain questionnaire for time of pain onset and level of pain at onset and at admission was analyzed.

RESULTS

None of the investigated biomarkers differed significantly between diagnosis categories. Most patients with IH had normal CRP, WBC, and D-dimer levels while their lactate levels were significantly lower (P = .029) compared with the rest of the cohort. Neither pain level nor pain duration differed between the groups.

CONCLUSION

This study shows that citrulline, I-FABP, and D-dimer cannot be used to diagnose IH and indicates that CRP, D-dimer, and lactate are rarely elevated by an IH. Furthermore, pain intensity and duration cannot differentiate patients with IH. A diagnostic laparoscopy remains the gold standard to diagnose and rule out an IH.

Colonic perforation following major burns: Experience from a burns center and a systematic review

BACKGROUND

Major burns complicated by stress ulceration and perforation of the stomach or duodenum is a recognized clinical phenomenon. Colonic perforation in burns patients is not common, and the overall incidence, diagnosis, intervention undertaken and mortality is incompletely described in the literature.

METHOD

We performed a systematic review of the literature on severe burns resulting in colonic perforation during the initial admission period. Relevant studies from January 1975 to June 2020 were retrieved from MEDLINE and EMBASE databases. Patient demographics, co-morbidities, total body surface area (TBSA) and anatomical region of burn, site of colonic perforation and management, nutrition, sepsis and microbiology, length of stay and overall outcome were extracted. We present a case series of five burns patients who had colonic perforations in our Specialist Burns Center.

RESULTS

We identified 54 studies, of which nine (two case series and seven case reports) met the inclusion criteria. Colonic perforation following burns was most common in middle-aged male patients with a proportion of patients having a history of mental health issues. In most cases, the TBSA associated with a colonic perforation was ≥30% (11/16 patients, 69%). Perforations mainly affected the right side of the colon (12/16 patients, 75%), usually occurring after the second week of admission (13/16 patients, 81%). Right-sided colonic perforations were associated with an increased mortality rate compared to left-sided perforations (42% vs 25%).

CONCLUSIONS

The current literature is mainly limited to case series and case reports and confirms that colonic perforations in burns patients are rare. Colonic perforations are related to the systemic effect of burn injuries including sepsis and gastrointestinal stasis. We have identified patients who are at higher risk of developing colonic perforations and have described the common findings in these patients. Through greater awareness early diagnosis and prompt intervention may be achieved to improve outcomes and reduce associated morbidity and mortality.

Fully automatic d-lactate assay using a modified commercially available method

Intestinal infarction is the fast-evolving endpoint of impaired blood perfusion to an intestinal segment which may have fatal outcome. Early diagnosis and treatment within 6 h reduce mortality. Currently, d-lactate is a promising biomarker, however, not available in the acute clinical setting. The aim of this study is implementation of d-lactate analysis in a routine clinical setting. We used a spectrophotometric method, based on enzymatic oxidation of d-lactate by d-lactate dehydrogenase (D-LDH) coupled to the reduction of nicotinamide-adenine dinucleotide (NAD⁺). The amount of NADH formed in this reaction is equivalent to d-lactate. The primary concern in this method is interfering NADH formed by oxidation of l-lactate by l-lactate dehydrogenase (L-LDH). A commercially available kit for d-lactate measurement was implemented on our existing automated routine laboratory equipment including pH-inactivation of L-LDH. Our setup fulfilled clinical quality goals. We were able to measure d-lactate with an acceptable performance of the analysis and a short turn-around time. The method can be used to distinguish between the expected cut-off for intestinal ischemia around 0.3 mM and the upper reference limit of 0.05 mM. With a turnaround time of just 9 min, the analysis has potential as a readily available detection of circulating d-lactate for early diagnosis of intestinal ischemia.

The Diagnostic Value of ischemia-modified albumin (IMA) and signal peptide-CUB-EGF domain-containing protein-1 (SCUBE-1) in an Experimental Model of Strangulated Mechanical Bowel Obstruction

BACKGROUND

Mechanical bowel obstruction (MBO) is one of the principal pathologies requiring emergency surgery and a significant worldwide cause of morbidity. The identification of patients in whom bowel obstruction resolves spontaneously is important in terms of preventing unnecessary surgical interventions and future potential adhesions. The decision-making process is difficult in patients presenting without classic examination findings.

METHODS

36 female Sprague-Dawley rats randomly divided into six experimental groups. In Group 1, 3 and 5, laparotomy was performed, with blood and tissue specimens being collected after 1, 2 and 6 h, respectively. In Group 2, 4 and 6, the ileum segment was ligated following laparotomy, and blood and tissue specimens were collected after 1, 2 and 6 h, respectively. The ileum specimens were examined macroscopically, after which 1-cm sections were taken and examined in terms of histopathological changes. IMA and SCUBE-1 levels were determined for each group, and macro- and microscopic tissue examination findings were compared between the groups.

RESULTS

Comparison within the groups exposed to waiting times of 1 h (groups 1 and 2), 2 h (groups 3 and 4) and 6 h (groups 5 and 6) revealed higher mean IMA and SCUBE-1 levels in rats undergoing ligation together with incision (groups 2, 4, and 6) compared to those undergoing laparotomy only (groups 1, 3, and 5). Correlation analysis was applied to determine the relationship between total scores obtained from histopathological examination and IMA and SCUBE-1 values. The analysis revealed strong, significant and positive correlation between histopathological examination scores and IMA (r=0.643, p=0.000) and SCUBE-1 (r=0.509, p=0.002) values.

CONCLUSION

The study findings showed that both IMA and SCUBE-1 values increased in a strangulated MBO model in rats. We think that IMA and SCUBE-1 values can be used as a markers of damage in the early period in strangulated MBO, and that the patient's surgery requirement can thus be determined in the early period.

Acute Mesenteric Ischemia

Background

Despite constant improvements in diagnostic as well as interventional and surgical techniques, acute mesenteric ischemia (AMI) remains a life-threatening emergency with high mortality rates. The time to diagnosis of AMI is the most important predictor of patients' outcome; therefore, prompt diagnosis and intervention are essential to reduce mortality in patients with AMI. The present review was performed to analyze potential risk factors and to help find ways to improve the outcome of patients with AMI.

Summary

Whereas AMI only applies to approximately 1% of all patients with an "acute abdomen," its incidence is rising up to 10% in patients >70 years of age. The initial clinical stage of AMI is characterized by a sudden onset of strong abdominal pain followed by a painless interval. Depending on the extent of disease, the symptoms of nonocclusive mesenteric ischemia (NOMI) and patients with a venous thrombosis can be very different from those of acute occlusive ischemia. Biphasic contrast-enhanced CT represents the gold standard for the diagnosis of arterial and venous occlusion. In case of a central occlusion of the superior mesenteric artery or signs of peritonitis, immediate surgery should be performed. If major bowel resection becomes necessary, critical residual intestinal length limits must be kept in mind. Endovascular techniques for arterial occlusion have taken on a much greater importance today. For stable patients with NOMI, interventional catheter angiography is recommended because it enables diagnosis and treatment with selective application of vasodilators. Depending on its degree, interventional treatment with a transhepatic catheter lysis should be considered for acute and chronic portal vein thrombosis.

Key Message

The prompt and targeted use of the appropriate diagnostics and interventions appears to be the only way to reduce the persistently high mortality rates for AMI.

A Novel Approach for Repairing Superior Mesenteric Artery Injury During Left Nephrectomy-6-year Follow-up

OBJECTIVE

To describe a novel approach for reconstructing the superior mesenteric artery (SMA) during left nephrectomy and review the literature.

MATERIALS AND METHODS

The patient was a 57-year-old man with left back pain from an unknown cause for more than 3 hours. A computed tomography scan showed a 12- × 15-cm firm mass and a subcapsular hematoma in the left kidney. It was considered to be bleeding and rupture of the solid renal mass, and because of persistent pain and no documented distant metastatic disease, a transperitoneal laparoscopic nephrectomy was elected, but the procedure was converted to open surgery for SMA injury. We reconstructed the SMA with end-to-end anastomosis between the SMA and the left renal artery stump.

RESULTS

At the 6-year follow-up, the patient had no intestine-related sequelae.

CONCLUSION

Our novel approach of an end-to-end anastomosis between the SMA and the left renal artery stump is an option for SMA injury, especially when orthotopic anastomosis or repair of the SMA is not indicated.

Stromal cell-derived factor-1 as a serologic biomarker for the diagnosis of colon ischemia with chronic cardiovascular disease

Colon ischemia (CI) is the most common ischemic disorder of the gastrointestinal tract. Although some markers of CI, such as procalcitonin and alkaline phosphatase, have been reported, few specific serum markers have been identified. We investigated whether serum stromal cell-derived factor-1 (SDF-1) is a specific marker of CI and clarified the relationship between serum SDF-1 level and CI according to a history of combined chronic cardiovascular disease (CVD).We measured SDF-1 level and other serological markers in 84 patients (control, n = 20; CI without chronic CVD, n = 21; chronic CVD without CI, n = 20; CI with chronic CVD, n = 23).Patients with CI were older than those without CI. There were more women in the CI groups than those without CI. At admission, SDF-1 level was significantly higher in patients having CI with chronic CVD (P < .001) than in other groups. SDF-1 level was significantly higher at admission than at discharge in patients having CI with chronic CVD (P < .001) but not in patients having CI without chronic CVD. SDF-1 level did not differ according to symptoms, involved sites, or duration of hospitalization. At a cutoff value of 0.5 pg/mL for the SDF-1 level in patients having CI with chronic CVD, the sensitivity and specificity for SDF-1 were 91.3% and 95%, respectively. The area-under-the-curve (AUC) value was 0.95. In the logistic regression analysis, an elevation of the SDF-1 level to >0.5 pg/mL was a significant indicator of CI with chronic CVD [odds ratio (OR), 114.914; 95% confidence interval, 10.51 to >999.999; P < .001].SDF-1 could be a useful early biomarker for the diagnosis of CI in patients with chronic CVD.

Comparison of diagnostic accuracy for nonocclusive mesenteric ischemia in models with biomarkers including intestinal fatty acid-binding protein in addition to clinical findings

BACKGROUND

Nonocclusive mesenteric ischemia (NOMI) is an acute and life-threatening gastrointestinal disorder, requiring rapid therapeutic intervention for ischemic bowel. However, its rapid detection remains challenging. This retrospective, observational study was aimed at comparing the diagnostic accuracy for NOMI in models of biomarkers, including intestinal fatty acid-binding protein (I-FABP), and clinical findings.

METHODS

All consecutive patients who presented to the emergency department of the study hospital with suspected NOMI were prospectively enrolled. Receiver operating characteristic analysis compared the diagnostic accuracy of I-FABP with traditional biomarkers (white blood cell count, C-reactive protein, lactate, creatine kinase, and D-dimer) alone and in combination with the baseline model established from clinical findings.

RESULTS

Of 96 patients with suspected NOMI, 25 (26.0%) were clinically diagnosed with NOMI. In-hospital mortality was higher in patients with NOMI than those with other conditions (56.0% vs. 4.2%, p < 0.001). Receiver operating characteristic analyses revealed that the I-FABP model had the highest area under the curve (0.805) in the diagnosis of NOMI, compared with other biomarkers. The diagnostic model of clinical findings including age, cardiovascular disease history, undergoing hemodialysis, hypotension, and consciousness disturbance in combination with I-FABP showed the best discrimination (area under the curve, 0.883), compared with other biomarkers. The bootstrap optimism estimate showed the lowest discrimination among the other models with other biomarkers (0.006).

CONCLUSION

The usefulness of I-FABP for final diagnosis of NOMI in patients with clinically suspected NOMI at the emergency department was internally validated. Further external validation study is warranted.

LEVEL OF EVIDENCE

Diagnostic test, level III.

Lactic acid level as an outcome predictor in pediatric patients with intussusception in the emergency department

Background

Intussusception decreases blood flow to the bowel, and tissue hypoperfusion results in increased lactic acid levels. We aimed to determine whether lactic acid levels are associated with pediatric intussusception outcomes.

Methods

The electronic medical records of our emergency department pediatric patients diagnosed with intussusception, between January 2015 and October 2018, were reviewed. An outcome was considered poor when intussusception recurred within 48 h of reduction or when surgical reduction was required due to air enema failure.

Results

A total of 249 patients were included in the study, including 39 who experienced intussusception recurrence and 11 who required surgical reductions; hence, 50 patients were included in the poor outcome group. The poor and good outcome groups showed significant differences in their respective blood gas analyses for pH (7.39 vs. 7.41, P = .001), lactic acid (1.70 vs. 1.30 mmol/L, P < .001), and bicarbonate (20.70 vs. 21.80 mmol/L, P = .036). Multivariable logistic regression analyses showed that pH and lactic acid levels were the two factors significantly associated with poor outcomes. When the lactic acid level cutoff values were ≥ 1.5, ≥2.0, ≥2.5, and ≥ 3.0 mmol/L, the positive predictive values for poor outcomes were 30.0, 34.6, 50.0, and 88.9%, respectively.

Conclusion

Lactic acid levels affect outcomes in pediatric patients with intussusception; higher lactic acid levels are associated with higher positive predictive values for poor outcomes.

Hypoxic-ischemic enterocolitis: a proposal of a new terminology for early NEC or NEC-like disease in preterm infants, a single-center prospective observational study

We aimed to investigate the role of hypoxia-ischemia in the pathophysiology of early NEC/NEC like disease (ENEC) and classic NEC/NEC like disease (CNEC) in preterm infants. In this pilot study, preterm infants who developed the clinical symptoms and signs of NEC/NEC like disease were divided into two groups as early (≤ 7 days, ENEC) or late (> 7 days, CNEC) groups. Beside clinical variables, serum L-lactate, endothelin-1 (ET-1), platelet activating factor (PAF), and intestinal fatty acid binding protein (I-FABP) levels were measured from umbilical/peripheric venous blood in the first hour of life and during the clinical presentation in all groups. A total of 86 preterm infants were enrolled in the study. In the ENEC group, the incidences of fetal umbilical artery Doppler velocimetry abnormalities, IUGR, and delayed passage of first meconium were higher. In addition, mean levels of L-lactate, ET-1, PAF, and I-FABP were higher in the first hour of life.Conclusion: Our study firstly showed that the dominant pathophysiological factor of ENEC is prenatal hypoxic-ischemic event where intestinal injury and inflammation begin in-utero and become clinically apparent in the first week of life. Therefore, we propose a new term "Hypoxic-Ischemic Enterocolitis (HIEnt)" for the definition of ENEC in preterm infants with prenatal hemodynamic disturbances and IUGR. This new sight can provide individualized preventive and therapeutic strategies for preterm infants.What is Known:• The pathophysiology of early necrotizing enterocolitis (NEC) or NEC-like disease which is seen in the first week of life seems different than classic necrotizing enterocolitis (CNEC) which is always seen after the first week of life.What is New:• This study suggests that perinatal hypoxic-ischemic process with inflammation is the point of origin of fetal intestinal injury leading to ENEC.• We propose a new term "Hypoxic-Ischemic Enterocolitis (HIEnt)" for the definition and differentiation of this unique clinical entity.

Effects of Receptor for Advanced Glycation End-Products (RAGE) Signaling on Intestinal Ischemic Damage in Mice

OBJECTIVE

Superior mesenteric artery ischemia and nonocclusive mesenteric ischemia are representative diseases of the vascular emergency known as irreversible transmural intestinal necrosis (ITIN). The receptor for advanced glycation end-products (RAGE) belongs to the immunoglobulin superfamily of extracellular ligands, which also includes high-mobility group box 1 (HMGB-1) and proteins of the S100 family. The HMGB-1 ligands have been implicated in the pathogenesis of various inflammatory disorders. This study was designed to investigate the relation between RAGE and ITIN in a murine acute intestinal ischemic model.

MATERIALS AND METHODS

ITIN was induced by clipping the cranial mesenteric artery and the peripheral blood vessels. Mucosal and blood samples were collected and analyzed by reverse-transcription PCR and immunohistochemistry for mucosal inflammation and levels of RAGE-related proteins. The influence of RAGE signaling on intestinal cell reproduction was investigated using the cell scratch test, an in vitro wound-healing assay. Finally, RAGE-related proteins and their respective inhibitors were administered intraperitoneally to ITIN model mice to determine their effects.

RESULTS

RAGE-expressing cells were located at the base of the intestinal crypts at day 0. As ITIN progressed, most of the damaged intestinal cells expressed RAGE, and ligands of RAGE such as HMGB-1, S100 A8/A9, and S100β were present in the crypt cells from the bottom to the top. The quantities of S100 A8/A9 and S100β were particularly high, above the levels found in other diseases. When S100 A8/A9 and S100β were applied to small intestinal epithelial cells in vitro, regeneration was significantly impeded. Inflammatory Gr1+ neutrophils and F4/80+ macrophages are involved in tissue ischemia. S100 A8/A9 enhances inflammatory myeloid cell influx.

CONCLUSIONS

RAGE-related proteins are elevated in ITIN model mice and impede intestinal regeneration in vitro. RAGE-related proteins may be a new therapeutic target or a new marker for ITIN.

Platelet to lymphocyte ratio as a predictive factor of 30-day mortality in patients with acute mesenteric ischemia

Introduction

Acute mesenteric ischemia is associated with high rates of mortality. The aim of this study was to investigate the prognostic value of the neutrophil to lymphocyte ratio (NLR) and the platelet to lymphocyte ratio (PLR) on 30-day outcomes in patients with acute mesenteric ischemia.

Material and methods

Consecutive patients who were admitted for an acute mesenteric ischemia were retrospectively included. The full white blood count at the time of admission to the hospital was recorded. The population was divided into 4 subgroups according to the quartiles of the NLR and the PLR. The 30-day outcomes including the mortality and the complications were compared among the subgroups.

Results

In total, 106 patients were included. A surgical treatment including revascularization and/or digestive resection was performed for 56 patients (52.8%). The 30-day all-cause mortality was 72 patients (67.9%). Patients with higher PLR value (PLR >429.3) had significantly higher rate of mortality compared to the other groups (80.8% vs 46.2%, 66.7% and 77.8%, p = 0.03). No significant difference on 30-day outcome was observed among the subgroups divided according to the NLR.

Conclusion

The PLR, but not the NLR, is a predictive factor of 30-day mortality in patients with acute mesenteric ischemia.

Biochemical markers of acute intestinal ischemia: possibilities and limitations

Acute intestinal ischemia is a relative rare abdominal emergency, associated with considerably high morbidity and mortality rates. Although the conventional diagnostic approach to acute intestinal ischemia entails a preliminary evaluation of signs and symptoms, followed by radiological and laboratory investigations, a definitive diagnosis is can usually be made after laparotomy, which still remains the gold standard diagnostic (and therapeutic) procedure. Several potential laboratory biomarkers have been investigated over the past decades, but none of these seems to reach a suitable diagnostic accuracy for an early and reliable diagnosis of intestinal ischemia. The aim of this narrative review is to provide an overview on traditional laboratory tests for diagnosing acute intestinal ischemia (i.e., complete blood count, D-dimer, blood gas analysis, total lactic acid, C-reactive protein and procalcitonin), and summarize current evidence regarding some emerging and potentially useful biomarkers such as D-lactate, intestinal fatty acid-binding protein (I-FABP), ischemia modified albumin (IMA), α-glutathione S-transferase (α-GST), interleukin-6 (IL-6), citrulline and smooth muscle protein of 22 kDa (SM22). Among the various tests, D-lactate, IMA and I-FABP are perhaps the most promising, since they are characterized by optimal sensitivity and relatively good specificity, early kinetics, and can be measured with assays suited for a rapid diagnosis.

Ischemic colitis caused by polycythemia vera: A case report and literature review

Polycythemia vera (PV) is a chronic myeloproliferative disorder originating from hematopoietic stem cells and complicated by thrombosis and bleeding. This report describes a case of ischemic colitis (IC) caused by PV and includes a review of the relevant literature. The patient was a 59-year-old male with a history of PV who presented with abdominal pain and hematochezia. Colonoscopy and histopathological examination results indicated suspected ischemic bowel disease. Following experimental anticoagulant therapy for 7 days, the patient no longer experienced abdominal pain and hematochezia had resolved. Colonoscopy review showed no obvious anomalies 1 month later. These data demonstrated that PV is an uncommon cause of IC.

Secondary peritonitis: principles of diagnosis and intervention

Secondary peritonitis accounts for 1% of urgent or emergent hospital admissions and is the second leading cause of sepsis in patients in intensive care units globally. Overall mortality is 6%, but mortality rises to 35% in patients who develop severe sepsis. Despite the dramatic growth in the availability and use of imaging and laboratory tests, the rapid diagnosis and early management of peritonitis remains a challenge for physicians in emergency medicine, surgery, and critical care. In this article, we review the pathophysiology of peritonitis and its potential progression to sepsis, discuss the utility and limitations of the physical examination and laboratory and radiographic tests, and present a paradigm for the management of secondary peritonitis.

Biological scoring system for early prediction of acute bowel ischemia after cardiac surgery: the PALM score

Background

Bowel ischemia is a life-threatening emergency defined as an inadequate vascular perfusion leading to bowel inflammation resulting from impaired colonic/small bowel blood supply. Main issue for physicians regarding bowel ischemia diagnosis lies in the absence of informative and specific clinical or biological signs leading to delayed management, resulting in a poorer prognosis, especially after cardiac surgery. The aim of the present series was to propose a simple scoring system based on biological data for the diagnosis of bowel ischemia.

Methods

In a retrospective monocentric study, patients admitted in cardiac ICU, after cardiovascular surgery, were screened for inclusion. According to a 1:2 ratio (case–control), matching between two groups was based on sex, type of cardiovascular surgery, and the operative period (per month). Patients were divided into two groups: “ischemic group” which corresponds to patients with confirmed bowel ischemia and “non-ischemic group” which corresponds to patients without bowel ischemia. Primary objective was the conception of a scoring system for the diagnosis of bowel ischemia. Secondary objectives were to detail the postoperative morbidity and the diagnostic features for the distinction between acute mesenteric ischemia and ischemic colitis.

Results

Forty-eight patients (1.3%) had confirmed bowel ischemia (“ischemic group”). According to the 2:1 matching, 96 patients were included in the “non-ischemic group.” Aspartate aminotransferase > 449 UI/L, lactate > 4 mmol/L, procalcitonin > 4.7 μg/L, and myoglobin > 1882 μg/L were found to be independently associated with bowel ischemia. Based on their respective odds ratios, points were assigned to each item ranging from 4 to 8. AUROCC [95% confidence interval] of the scoring system to diagnose bowel ischemia was 0.93 [0.91–0.95], p < 0.001. The optimal threshold after bootstrapping was ≥ 14 points; this yielded a sensitivity of 85.4%, a specificity of 94.8%, a positive likelihood ratio of 16.42, a negative likelihood ratio of 0.15, a Youden’s index of 0.802, and a diagnostic odds ratio of 106.62.

Conclusions

A biological scoring system based on PCT, ASAT, lactate, and myoglobin measurement allows the diagnosis of bowel ischemia after cardiac surgery with high accuracy. This score could help clinician to propose an early diagnosis and an early treatment in this high mortality disease.

Electronic supplementary material

The online version of this article (10.1186/s13613-018-0395-5) contains supplementary material, which is available to authorized users.

Experimental Hemorrhagic Shock Protocol in Swine Models: The Effects of 21-Aminosteroid on the Small Intestine

Background

The protective potential of lazaroids has been reported in previous studies on ischemia/reperfusion and induced hemorrhagic shock protocols.

Objectives

The present study is the first experimental protocol on the effects of the antioxidant factor U-74389G on the small intestine of swine models in a hemorrhagic shock protocol and resuscitation with 3 different types of fluids.

Methods

The study included 49 Landrace breed swine that were divided into groups of 7 each. Hemorrhage was provoked 45 minutes after starting the surgical protocol (0 minutes), followed by resuscitation starting 30 minutes after haemorrhage ceased by using 3 different fluids. Three groups (Group A, resuscitation using blood; Group B, resuscitation with Ringer’s lactate solution; and Group C, resuscitation with hypertonic saline solution) underwent resuscitation with fluid alone, and another 3 groups (named A', B,' and C') were administered lazaroid U-74389G in addition to fluid. Control Group S underwent all the surgical procedures without hemorrhagic shock. Vital signs, complete blood count, and biochemical markers were analyzed, and tissue samples of the small intestine were collected from all animals. Further, malondialdehyde, tumor necrosis factor-α, and levels of inflammation in the tissue sample were measured.

Results

In Group S-A-A' and Group S-C-C', the analysis did not show statistically significant differences in the percentage changes of histopathology, malondialdehyde, and tumor necrosis factor-α through time. In Group S-B-B', the malondialdehyde levels in the small intestine were reduced in both the B and B' groups, without lazaroid (Group B) (P = 0.038) and lazaroid (Group B') (P = 0.011), compared with Group S (control), but the group without lazaroid (Group B) had greater reduction in malondialdehyde levels than the group treated with lazaroid (Group B'). With regard to the biochemistry results, 24% reduction was observed for alkaline phosphatase (P = 0.022) in Group A' treated with lazaroid compared with that in the untreated group. Lastly, for the complete blood count parameters, a 14% reduction in white blood cells was observed in Group B', which was treated with lazaroid in all phases (P = 0.015) (absolute value = 6.23) compared with Group B (absolute value = 13.74).

Conclusions

Despite few initial findings of this study suggesting that administration of lazaroid U-74389G may have some potential in attenuation of the effects of hemorrhagic shock in the small intestine of swine models, no differences remained after correction for multiple comparisons was made. Therefore, further research is required to investigate this result thoroughly.

Diagnostic accuracy of novel serological biomarkers to detect acute mesenteric ischemia: a systematic review and meta-analysis

Laparotomy remains the gold standard for diagnosis of acute mesenteric ischemia (AMI), but is often unhelpful or too late due to non-specific clinical and radiological signs. This systematic review and meta-analysis aims to evaluate the diagnostic accuracy of the novel serological biomarkers intestinal fatty acid-binding protein (I-FABP), α-glutathione S-transferase (α-GST), D-lactate, ischemia modified albumin (IMA), and citrulline to detect AMI. A systematic search of electronic databases was performed to identify all published diagnostic accuracy studies on I-FABP, α-GST, D-lactate, IMA, and citrulline. Articles were selected based on pre-defined inclusion and exclusion criteria. Risk of bias and applicability were assessed. Two-by-two contingency tables were constructed to calculate accuracy standards. Summary estimates were computed using random-effects models. The search yielded 1925 papers, 21 were included in the final analysis. Pooled sensitivity and specificity for investigated biomarkers were: I-FABP (Uden); 79.0 (95% CI 66.5-88.5) and 91.3 (87.0-94.6), I-FABP (Osaka); 75.0 (67.9-81.2) and 79.2 (76.2-82.0), D-lactate; 71.7 (58.6-82.5) and 74.2 (69.0-79.0), α-GST; 67.8 (54.2-79.5) and 84.2 (75.3-90.9), IMA; 94.7 (74.0-99.9) and 86.4 (65.1-97.1), respectively. One study investigated accuracy standards for citrulline: sensitivity 39% and specificity 100%. The novel serological biomarkers I-FABP, α-GST, IMA, and citrulline may offer improved diagnostic accuracy of acute mesenteric ischemia; however, further research is required to specify threshold values and accuracy standards for different aetiological forms.

Diagnosis biomarkers in acute intestinal ischemic injury: so close, yet so far

Acute intestinal ischemic injury (i3) is a life-threatening condition with disastrous prognosis, which is currently difficult to diagnose at the early stages of the disease; a rapid diagnosis is mandatory to avoid irreversible ischemia, extensive bowel resection, sepsis and death. The overlapping protein expression of liver and gut related to the complex physiopathology of the disease, the heterogeneity of the disease and its relative rarity could explain the lack of a useful early biochemical marker of i3. Apart from non-specific biological markers of thrombosis, hypoxia inflammation, and infection, several more specific biomarkers in relation with the gut barrier dysfunction, the villi injury and the enterocyte mass have been used in the diagnosis of acute i3. It includes particularly D-lactate, intestinal fatty acid-binding protein (FABP) and citrulline. Herein, we will discuss leading publications concerning these historical markers that point out the main limitations reagrding their use in routine clinical practice. We will also introduce the first and limited results arising from omic studies, underlying the remaining effort that needs to be done in the field of acute i3 biological diagnosis, which remains a challenge.

Acute mesenteric ischemia: guidelines of the World Society of Emergency Surgery

Acute mesenteric ischemia (AMI) is typically defined as a group of diseases characterized by an interruption of the blood supply to varying portions of the small intestine, leading to ischemia and secondary inflammatory changes. If untreated, this process will eventuate in life threatening intestinal necrosis. The incidence is low, estimated at 0.09–0.2% of all acute surgical admissions. Therefore, although the entity is an uncommon cause of abdominal pain, diligence is always required because if untreated, mortality has consistently been reported in the range of 50%. Early diagnosis and timely surgical intervention are the cornerstones of modern treatment and are essential to reduce the high mortality associated with this entity. The advent of endovascular approaches in parallel with modern imaging techniques may provide new options. Thus, we believe that a current position paper from World Society of Emergency Surgery (WSES) is warranted, in order to put forth the most recent and practical recommendations for diagnosis and treatment of AMI. This review will address the concepts of AMI with the aim of focusing on specific areas where early diagnosis and management hold the strongest potential for improving outcomes in this disease process.

Some of the key points include the prompt use of CT angiography to establish the diagnosis, evaluation of the potential for revascularization to re-establish blood flow to ischemic bowel, resection of necrotic intestine, and use of damage control techniques when appropriate to allow for re-assessment of bowel viability prior to definitive anastomosis and abdominal closure.

Effect of Remote Ischemic Preconditioning on Intestinal Ischemia-Reperfusion Injury in Adults Undergoing On-Pump CABG Surgery: A Randomized Controlled Pilot Trial

OBJECTIVE

Cardiopulmonary bypass (CPB) surgery commonly threatens the heart and remote organs with ischemia-reperfusion injury. Transient episodes of ischemia to nonvital tissue, known as remote ischemic preconditioning (RIPC), is thought to help local and remote vital organs to withstand subsequent ischemic insults.

DESIGN

Prospective, randomized, double-blinded control trial.

SETTING

Tertiary referral academic teaching hospital.

PARTICIPANTS

Thirty patients undergoing elective CPB surgery INTERVENTION: RIPC was achieved via three 5-minute cycles of upper limb ischemia using a blood pressure cuff or control (sham cuff).

MEASUREMENTS AND MAIN RESULTS

Primary outcome was the occurrence of intestinal injury, as measured by an increase in intestinal fatty acid binding protein (I-FABP). Secondary outcomes included incidence of gastrointestinal complications and duration of intensive care unit (ICU) stay. RIPC did not affect serum IFABP levels at the end of surgery and on the first postoperative day (p = 0.697 and p = 0.461, respectively). For all patients, mean I-FABP levels significantly increased at the end of surgery and decreased to under baseline levels on the first postoperative day (from a mean [± standard deviation] baseline value of 764 ± 492 pg/mL to 2,002 ± 974 pg/mL and decreased to 568 ± 319 pg/mL, p < 0.001). All patients remained clinically absent of gastrointestinal complications until hospital discharge. Duration of ICU stay was not correlated with I-FABP levels at the end of surgery. Neither duration of CPB nor duration of aortic clamping significantly correlated with postoperative I-FABP levels.

CONCLUSIONS

These findings suggest that RIPC does not affect intestinal injury in patients undergoing CPB surgery. In patients undergoing cardiac surgery, intestinal injury appears to be moderate and transient without any clinical relevant complication.

Autophagy can alleviate severe burn-induced damage to the intestinal tract in mice

BACKGROUND

The present study was designed to examine the effect of autophagy and apoptosis on intestinal injury in mice after severe burns.

METHODS

Kunming mice were subjected to third degree burns over 30% of the total body surface area. Damage to the intestine was assessed by examining changes in intestinal mucosal morphology, enzyme-linked immunosorbent assay of serum d-lactate, diamine oxidase, lipopolysaccharide, interleukin-6, and tumor necrosis factor α (marker of intestinal damage), hematoxylin and eosin staining, and Western blotting under 4 experimental conditions: control group, burn only (burn group), burn and administration of rapamycin to stimulate intestinal autophagy (rapamycin group), or burn and administration of 3-methyladenine to inhibit intestinal autophagy (3-methyladenine group).

RESULTS

At day 1 postburn, the expression levels of light chain 3 II, beclin-1, and cleaved caspase-3 were significantly greater in all 3 groups of mice subjected to the burn injury than in the control group 1 day postburn; while the levels of light chain 3 II and beclin-1 were significantly greater and those of cleaved caspase-3 were significantly less in the rapamycin group than in the burn group. In contrast, light chain 3 II and beclin-1 levels were significantly less and those of cleaved caspase-3 significantly greater in the 3-methyladenine group. All 3 groups subjected to burn injury showed significantly increased levels of d-lactate, diamine oxidase, lipopolysaccharide, interleukin-6, and tumor necrosis factor α. Of the 3 groups, the rapamycin group exhibited the least observed levels, the 3-methyladenine group the greatest, and the burn group intermediate. Pathologic sections of the intestinal tissue showed that all 3 burn groups exhibited severe intestinal mucosal damage at 1 day postburn. The condition of the 3-methyladenine treatment group was worse than that of the rapamycin treatment group, but better than that of the burn group.

CONCLUSION

Intestinal autophagy is activated in response to intestinal apoptosis after severe burns and may alleviate burn-induced intestinal injury.

Accuracy of using serum D-dimer for diagnosis of acute intestinal ischemia: A meta-analysis

OBJECTIVE

The purpose of this meta-analysis is to comprehensively assess the accuracy of serum D-dimer for the diagnosis of acute intestinal ischemia.

METHODS

Diagnostic studies of D-dimer for accurate diagnosis of acute intestinal ischemia were extracted from 6 databases, and prospective and retrospective studies that provided adequate data on sensitivity and specificity were included here. Sensitivity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR) were calculated. The overall diagnostic performance of D-dimer was assessed by plotting a summary receiver operating characteristic curve (SROC) and calculating the area under the curve (AUC).

RESULTS

A total of 1300 patients with suspected acute intestinal ischemia from 12 studies met the inclusion criteria. The combined sensitivity, specificity, PLR, NLR, and DOR were 0.94 (95% CI: 0.87-0.97), 0.50 (95% CI: 0.40-0.61), 1.9 (95% CI: 1.5-2.3), 0.12 (95% CI: 0.05-0.26), and 16 (95% CI: 7-39), respectively. The AUC was 0.81 (95% CI: 0.78-0.84).

CONCLUSION

The results of this meta-analysis suggested that plasma D-dimer detection might be a useful means of identifying patients with acute intestinal ischemia of the abdomen.

Serological markers for human intestinal ischemia: A systematic review

Early and accurate diagnosis of intestinal ischemia is important in order to provide rapid and correct treatment and reduce morbidity and mortality rates. Clinical signs and symptoms are often unspecific. This systemic review sums up literature regarding human plasma biomarkers for acute mesenteric ischemia reported during the last ten years. Classic, general markers, including lactate, white cell count, base excess, show poor diagnostic accuracy for intestinal ischemia. Preliminary results for ischemia-modified albumin are promising, which is also true for the inflammatory marker procalcitonin. Best diagnostic accuracy is described for D-dimer, a-Glutathione S-transferase (a-GST) and Intestinal fatty acid binding protein (I-FABP), reflecting coagulation activity and mucosal damage respectively. Future studies should be directed at phase four questions (Do patients who undergo the diagnostic test fare better (in their ultimate health outcomes) than similar patients who do not?) for these markers and the identification of additional, novel plasma biomarkers signaling various types and stages of intestinal ischemia.

Acute intestinal damage following severe burn correlates with the development of multiple organ dysfunction syndrome: A prospective cohort study

BACKGROUND

Severely burned patients occasionally suffer intestinal ischemia leading to a fatal outcome, and the gut is considered a "motor" driving the development of multiple organ failure. However, in clinical settings, it has been difficult to assess acute intestinal damage following burn and its consequence to patient outcome. Intestinal fatty acid binding protein (I-FABP) is a known biomarker for diagnosing intestinal ischemia/damage. This study aimed to assess the extent of intestinal damage using serial I-FABP measurements following severe burn and to clarify the association between intestinal damage and the development of organ dysfunctions.

METHODS

Patients aged >15years old who suffered burn over 20% total body surface area (TBSA) were enrolled in this prospective cohort study. Patients with cardiac arrest on admission or who were transferred >24h after injury were excluded. Patients with chemical burn were also excluded. Burn size and Acute Physiology and Chronic Health Evaluation II (APACHE II) score were recorded at the time of patient enrollment. I-FABP was measured on admission and at 1, 4, 7, 14, and 30days following injury. Other biomarkers such as lactate, lactate dehydrogenase (LDH), creatine kinase (CK), aspartate aminotransferase (AST), alanine aminotransferase, amylase, and creatinine (Cre) were also measured at the same time points as I-FABP. We also evaluated the serial change in Sequential Organ Failure Assessment (SOFA) score.

RESULTS

The study included 32 patients. Serum I-FABP level on the day of admission was significantly increased in the patients compared with healthy controls. Increased I-FABP levels were normalized at 4days after injury. The serum level of I-FABP on the day of admission correlated with %TBSA (III) and APACHE II score. A high I-FABP level on admission was associated with the subsequent development of multiple organ dysfunction. The increase in I-FABP level also correlated with increases of AST, LDH, and CK levels.

CONCLUSIONS

Serum level of I-FABP on admission day does not correlate with burn size, but with the deep burn area. The gut might be a crucial target organ following severe burn, and gut damage could have an important role in the development of multiple organ dysfunction.

Transition of intestinal fatty acid-binding protein on hypothermic circulatory arrest with cardiopulmonary bypass

Introduction:

Intestinal fatty acid-binding protein (I-FABP) is increasingly employed as a highly specific marker of intestinal necrosis. However, the value of this marker associated with cardiovascular surgery with hypothermic circulatory arrest is unclear. The aim of this study was to measure serum I-FABP levels and provide the transition of I-FABP levels with hypothermic circulatory arrest to help in the management of intestinal perfusion.

Methods:

From August 2011 to September 2013, 33 consecutive patients who had aortic arch surgery with hypothermic circulatory arrest or heart valve surgery performed were enrolled in the study. Twenty patients had aortic surgery with hypothermic (23-29°C) circulatory arrest and 13 patients had heart valve surgery with cardiopulmonary bypass (33°C).

Results:

I-FABP levels increased, both in patients undergoing aortic surgery with hypothermic circulatory arrest and heart valve surgery with cardiopulmonary bypass, reaching peak levels shortly after the administration of protamine. I-FABP levels in patients with aortic surgery were significantly higher with circulatory arrest. They reached peak levels immediately after recirculation and there was a significant drop at the end of surgery (p<0.001). I-FABP levels in heart valve surgery were gradually increased, with the highest at the administration of protamine; they gradually decreased. Peak I-FABP levels were significantly higher in patients undergoing aortic surgery with hypothermic circulatory arrest than in patients with heart valve surgery. However, no postoperative reperfusion injury occurred in the intestinal tract due to the use of hypothermic organ protection.

Conclusion:

Plasma I-FABP monitoring could be a valuable method for finding an intestinal ischemia in patients with cardiovascular surgery.