Plasma biomarkers for early diagnosis of acute intestinal ischemia

Current Approaches for Mesenteric Ischemia and Visceral Aneurysms

This article provides an overview of acute mesenteric ischemia, chronic mesenteric ischemia, and visceral aneurysms, with a focus on treatment. Acute mesenteric ischemia can be a challenging diagnosis. Early recognition and adequate revascularization are key to patient outcomes. Chronic mesenteric ischemia is a more insidious process, typically caused by atherosclerosis. Various options for revascularization exist, which must be tailored to each patient. Visceral aneurysms are rare and the natural history is not well defined. However, given the risk of rupture and high mortality, treatment may be complex.

L-FABP and NGAL are novel biomarkers for detection of abdominal injury and hemorrhagic shock

INTRODUCTION

Delayed diagnosis of abdominal injuries and hemorrhagic shock leads to secondary complications and high late mortality in severely traumatized patients. The liver fatty acid-binding protein (L-FABP) is expressed in intestine, liver and kidney; the neutrophil gelatinase-associated lipocalin (NGAL) in colon and kidney. We hypothesized that l-FABP is an early biomarker for abdominal injury and hemorrhagic shock and that l-FABP and NGAL are specific markers for detection of liver and/or kidney injuries.

PATIENTS AND METHODS

Traumatized patients with an age ≥18 years and an abdominal injury (AIS_abd≥2), independently from Injury Severity Score (ISS), were prospectively included from 04/2018 to 05/2021. 68 patients had an abdominal injury ("Abd") and 10 patients had an abdominal injury with hemorrhagic shock ("HS Abd"). 41 patients without abdominal injury and hemorrhagic shock but with an ISS ≥ 25 ("noAbd") were included as control group. Four abdominal subgroups with isolated organ injuries were defined. Plasma l-FABP and NGAL levels were measured at admission (ER) and up to two days post-trauma.

RESULTS

All patient groups had a median ISS≥25. In ER, median l-FABP levels were significantly higher in "HS Abd" group (1209.2 ng/ml [IQR=575.2-1780.3]) compared to "noAbd" group (36.4 ng/ml [IQR=14.8-88.5]), and to "Abd" group (41.4 ng/ml [IQR=18.0-235.5]), p<0.001. In matched-pair-analysis l-FABP levels in the group "Abd" were significantly higher (108.3 ng/ml [IQR=31.4-540.9]) compared to "noAbd" (26.4 ng/ml [IQR=15.5-88.8]), p = 0.0016. l-FABP correlated significantly with clinical parameters of hemorrhagic shock; the optimal cut-off level of l-FABP for detection was 334.3 ng/ml (sensitivity: 90%, specificity: 78%). Median l-FABP-levels were significantly higher in patients with isolated liver or kidney injuries and correlated significantly with AST, ALT and creatinine value. Median NGAL levels in the ER were significantly higher in "HS Abd" group (115.9 ng/ml [IQR=90.6-163.8]) compared to "noAbd" group (58.5 ng/ml [IQR=41.0-89.6],p<0.001) and "Abd" group (70.5 ng/ml [IQR=53.3-115.5], p<0.05). The group "Abd" showed significant higher median NGAL levels compared to "noAbd", p = 0.019. NGAL levels correlated significantly with clinical parameters of hemorrhagic shock.

CONCLUSION

L-FABP and NGAL are novel biomarkers for detection of abdominal trauma and hemorrhagic shock. l-FABP may be a useful and promising parameter in diagnosis of liver and kidney injuries, NGAL failed to achieve the same.

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.

The Effect of Acupuncture on Enteral Nutrition and Gastrointestinal Dynamics in Patients Who Have Suffered a Severe Stroke

OBJECTIVE

This study aimed to explore and analyze the effect of acupuncture on improving the enteral nutrition level and gastrointestinal dynamics in patients who had suffered a severe stroke.

METHODS

A total of 122 patients who experienced a severe stroke who were treated in the intensive care unit of the Affiliated Hospital of Hebei University (China) between September 2021 and March 2022 were randomly divided into two groups as follows: 1) the observation group, the participants of which received acupuncture combined with early enteral nutrition (61 cases); 2) the control group, the participants of which received early enteral nutrition (61 cases). Following treatment, the hemoglobin, neutrophil count, blood glucose, albumin, pre-albumin, immediate postprandial antral area, antral contraction frequency (at 2 min), and antral motility index on days 1 and 7 of treatment were compared between the two groups.

RESULTS

The total clinical effective rate was 96.72% in the observation group and 77.05% in the control group. The curative effect comparison between the two groups after seven days of treatment showed a lower probability of gastrointestinal bleeding, faster recovery of gastrointestinal motility, and a higher level of nutrient absorption in the observation group. Serum albumin, pre-albumin, hemoglobin, total lymphocyte count, immediate postprandial maximum (max) and minimum (mix) area of the gastric antrum, antral contraction frequency (at 2 min), and antral motility index were higher in the observation group than in the control group (P < 0.05). The difference in blood glucose levels between the two groups was not statistically significant (P > 0.05).

CONCLUSION

Acupuncture improved the enteral nutrition status of patients who had suffered a severe stroke and promoted gastrointestinal motility. The combination of acupuncture and early enteral nutrition could reduce damage to the gastrointestinal mucosal barrier caused by stress, changes in metabolism, and improved gastrointestinal function.

Prediction and management of strangulated bowel obstruction: a multi-dimensional model analysis

BACKGROUND

Distinguishing strangulated bowel obstruction (StBO) from simple bowel obstruction (SiBO) still poses a challenge for emergency surgeons. We aimed to construct a predictive model that could distinctly discriminate StBO from SiBO based on the degree of bowel ischemia.

METHODS

The patients diagnosed with intestinal obstruction were enrolled and divided into SiBO group and StBO group. Binary logistic regression was applied to identify independent risk factors, and then predictive models based on radiological and multi-dimensional models were constructed. Receiver operating characteristic (ROC) curves and the area under the curve (AUC) were calculated to assess the accuracy of the predicted models. Via stratification analysis, we validated the multi-dimensional model in the prediction of transmural necrosis both in the training set and validation set.

RESULTS

Of the 281 patients with SBO, 45 (16.0%) were found to have StBO, while 236(84.0%) with SiBO. The AUC of the radiological model was 0.706 (95%CI, 0.617-0.795). In the multivariate analysis, seven risk factors including pain duration ≤ 3 days (OR = 3.775), rebound tenderness (OR = 5.201), low-to-absent bowel sounds (OR = 5.006), low levels of potassium (OR = 3.696) and sodium (OR = 3.753), high levels of BUN (OR = 4.349), high radiological score (OR = 11.264) were identified. The AUC of the multi-dimensional model was 0.857(95%CI, 0.793-0.920). In the stratification analysis, the proportion of patients with transmural necrosis was significantly greater in the high-risk group (24%) than in the medium-risk group (3%). No transmural necrosis was found in the low-risk group. The AUC of the validation set was 0.910 (95%CI, 0.843-0.976). None of patients in the low-risk and medium-risk score group suffered with StBO. However, all patients with bowel ischemia (12%) and necrosis (24%) were resorted into high-risk score group.

CONCLUSION

The novel multi-dimensional model offers a useful tool for predicting StBO. Clinical management could be performed according to the multivariate score.

The Association of Coloproctology of Great Britain and Ireland consensus guidelines in emergency colorectal surgery

AIM

There is a requirement for an expansive and up to date review of the management of emergency colorectal conditions seen in adults. The primary objective is to provide detailed evidence-based guidelines for the target audience of general and colorectal surgeons who are responsible for an adult population and who practise in Great Britain and Ireland.

METHODS

Surgeons who are elected members of the Association of Coloproctology of Great Britain and Ireland Emergency Surgery Subcommittee were invited to contribute various sections to the guidelines. They were directed to produce a pathology-based document using literature searches that were systematic, comprehensible, transparent and reproducible. Levels of evidence were graded. Each author was asked to provide a set of recommendations which were evidence-based and unambiguous. These recommendations were submitted to the whole guideline group and scored. They were then refined and submitted to a second vote. Only those that achieved >80% consensus at level 5 (strongly agree) or level 4 (agree) after two votes were included in the guidelines.

RESULTS

All aspects of care (excluding abdominal trauma) for emergency colorectal conditions have been included along with 122 recommendations for management.

CONCLUSION

These guidelines provide an up to date and evidence-based summary of the current surgical knowledge in the management of emergency colorectal conditions and should serve as practical text for clinicians managing colorectal conditions in the emergency setting.

mtDNA-STING pathway promotes necroptosis-dependent enterocyte injury in intestinal ischemia reperfusion

Intestinal ischemia reperfusion (I/R) injury is the important pathogenesis for acute intestinal barrier disruption. The STING signaling is associated with gut homeostasis and barrier integrity. However, the biological function and regulation of STING signaling in intestinal I/R injury are not yet fully understood. As the ligand of STING signaling, the mitochondrial DNA (mtDNA) has been found to be associated with necroptosis. It still remains unknown whether mtDNA-STING signaling triggers intestinal necroptosis in intestinal I/R injury. We found that circulating RIPK3 was significantly increased and had a positive correlation with markers of enterocyte injury in critically ill patients with intestinal injury. Moreover, the levels of circulating mtDNA were also associated with the levels of circulating RIPK3. To explore the relationship between mtDNA and intestinal necroptosis, mice were treated with the intraperitoneal injection of mtDNA, and necroptosis signaling was remarkably activated and the inhibition of necroptosis alleviated mtDNA-induced intestinal injury. Furthermore, STING knockout mice showed an alleviated intestinal necroptosis. In intestinal I/R injury, mtDNA was released from IECs and necroptosis was also triggered, companied with a significant decrease of RIPK3 in the intestine. STING knockout mice markedly attenuated intestinal necroptosis and intestinal I/R injury. Finally, we found that mtDNA-mediated STING signaling triggered necroptosis through synergistic IFN and TNF-α signaling in primary IECs. Our results indicated that mtDNA-STING signaling can contribute to intestinal I/R injury by promoting IEC necroptosis. STING-mediated both IFN and TNF-α signaling can trigger intestinal nercroptosis.

Normal Lactate and Unenhanced CT-Scan Result in Delayed Diagnosis of Acute Mesenteric Ischemia

INTRODUCTION

To investigate the factors associated with a delayed diagnosis (DD) of acute mesenteric ischemia (AMI).

METHODS

An observational cohort study from an intestinal failure center. The primary outcome was DD >24 hours.

RESULTS

Between 2006 and 2015, 74 patients with AMI were included and 39 (53%) had a DD. Plasma lactate <2 mmol/L (odd ratio: 3.2; 95% confidence interval: 1.1-9.1; P = 0.03) and unenhanced computed tomography scan (odds ratio: 5.9; 95% confidence interval: 1.4-25.8; P = 0.01) were independently associated with DD.

DISCUSSION

Suspicion of AMI should no longer be affected by normal plasma lactate levels and should prompt evaluation by a contrast-enhanced computed tomography-scan.

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.

Is I-FABP not only a marker for the detection abdominal injury but also of hemorrhagic shock in severely injured trauma patients?

Background

Hemorrhagic shock can lead to intestinal damage with subsequent hyperinflammation and multiple organ dysfunction syndrome (MODS). The intestinal fatty acid-binding protein (I-FABP) is solely expressed in the intestine and is released extracellulary after tissue damage. This study evaluates the validity of I-FABP as an early biomarker to detect hemorrhagic shock and abdominal injury.

Patients and methods

Severely injured patients with an Injury Severity Score (ISS) ≥ 16 points and an age ≥ 18 years, admitted from January 2010 to December 2016, were included. Overall, 26 patients retrospectively presented with hemorrhagic shock to the emergency room (ER): 8 patients without abdominal injury ("HS noAbd") and 18 patients with abdominal injury ("HS Abd"). Furthermore, 16 severely injured patients without hemorrhagic shock and without abdominal injury ("noHS noAbd") were retrospectively selected as controls. Plasma I-FABP levels were measured at admission to the ER and up to 3 days posttraumatic (d1-d3).

Results

Median I-FABP levels were significantly higher in the "HS Abd" group compared with the "HS noAbd" group (28,637.0 pg/ml [IQR = 6372.4-55,550.0] vs. 7292.3 pg/ml [IQR = 1282.5-11,159.5], p < 0.05). Furthermore, I-FABP levels of both hemorrhagic shock groups were significantly higher compared with the "noHS noAbd" group (844.4 pg/ml [IQR = 530.0-1432.9], p < 0.05). The time course of I-FABP levels showed a peak on the day of admission with a subsequent decline in the post-traumatic course. Furthermore, significant correlations between I-FABP levels and clinical parameters of hemorrhagic shock, such as hemoglobin, lactate value, systolic blood pressure (SBP), and shock index, were found.The optimal cut-off level of I-FABP for detection of hemorrhagic shock was 1761.9 pg/ml with a sensitivity of 85% and a specificity of 81%.

Conclusion

This study confirmed our previous observation that I-FABP might be used as a suitable early biomarker for the detection of abdominal injuries in general. In addition, I-FABP may also be a useful and a promising parameter in the diagnosis of hemorrhagic shock, because of reflecting low intestinal perfusion.

Acute mesenteric ischemia (AMI): absence of renal insufficiency and performance of early bowel resection may indicate improved outcomes

PURPOSE

Acute mesenteric ischemia (AMI) is still associated with very high morbidity and mortality while the rareness and heterogeneity hamper the establishment of evidence-based guidelines. We sought to help standardize contemporary treatment by a cohort study at our tertiary center in the rising endovascular age.

METHODS

A retrospective cohort study was conducted from 2005 to 2015. Patients with occlusive (OMI), non-occlusive (NOMI), and venous mesenteric ischemia (VMI) were compared with respect to clinical and treatment parameters as well as outcome.

RESULTS

The study cohort consisted of 48 patients composed of 27 males and 21 females with an average age of 63 years and an average BMI of 25.1 kg/m². In 48% of patients (N=23), an acute arterial OMI had occurred while NOMI was present in 31% (N=15) and VMI in 21% (N=10). Interventional and intraoperative recanalizations were significantly more often required in OMI patients compared with other entities (p=0.003). Patients with venous mesenteric ischemia had a significant better overall survival than patients with OMI or NOMI in the univariate analysis (p=0.027). Patients with renal failure had a 14.7-fold higher relative risk (Cox p=0.013) and patients without bowel resection during primary surgery had a 17.8-fold higher relative risk (Cox p=0.047) to die of AMI in the postoperative course.

CONCLUSIONS

AMI remains a rare but oftentimes fatal disease. Our study provides evidence that outcome may depend on the AMI subtype, presence of renal insufficiency, and early bowel resection. Further research should help individualize treatment for optimized outcomes.

Necessity of revascularization for acute mesenteric ischemia in symptomatic patients with spontaneous isolated dissection of the superior mesenteric artery

Objectives

We evaluated the necessity of revascularization for acute mesenteric ischemia in symptomatic patients with spontaneous isolated dissection of the superior mesenteric artery.

Methods

This retrospective study included 28 consecutive, symptomatic patients with spontaneous isolated dissection of the superior mesenteric artery treated at our hospital between December 2005 and December 2017. Patients with concomitant aortic dissection were excluded. We reviewed the patients’ clinical presentation; laboratory evaluations; computed tomography findings, including the true lumen residual ratio (i.e., the minimum true lumen size compared to the diameter of the transverse section of the dissected artery) at the time of admission; the number of patients who were suspected of having bowel ischemia; and the number of patients who required surgical or endovascular treatment and their outcomes. Additionally, to evaluate the true lumen residual ratio in symptomatic patients with bowel ischemia, the true lumen residual ratio in those with abnormal laboratory data were compared with that in those without abnormal laboratory data. Initial true lumen residual ratio values were also compared with final values. Furthermore, we assessed the clinical details of patients who had bowel necrosis. Categorical variables were compared using the χ2 test or Fisher’s exact test, and continuous values were presented as either the mean ± standard deviation or median (interquartile range 25–75%). Variables were analyzed using Student’s t-test or the Mann–Whitney U test.

Results

The patients’ age ranged between 41 and 85 years, and 25 were men. Although nine patients were suspected of having acute mesenteric ischemia, only one underwent bowel resection. None of the patients had an indication for revascularization. The true lumen residual ratio of the nine patients with abnormal laboratory data were significantly lower than those of the 19 without abnormal laboratory data (10 [0–25]% vs. 40 [20–50]%, p = 0.005). The patient who underwent bowel resection had a true lumen residual ratio of 10%; however, there was no obvious abnormal laboratory data suggestive of bowel necrosis. Dissections were managed conservatively in all patients. True lumen residual ratio increased from initial value of 30 (10–48)% to 98 (60-100)%at the final imaging study ( p < 0.0001). There were no adverse events related to the mesenteric circulation during the follow-up period of 2–11 years.

Conclusions

Reintervention is rarely required for spontaneous isolated dissection of the superior mesenteric artery, even in symptomatic patients, and spontaneous resolution of the luminal compromise is the rule.

Serological biomarkers for acute mesenteric ischemia

Acute mesenteric ischemia (AMI) defines a complex of conditions characterized by an interruption of the splanchnic circulation, leading to insufficient oxygen delivery or utilization to fill the metabolic needs of the visceral organs. Early diagnosis and immediate therapy are the cornerstones of early ischemia to reach a successful outcome and are necessary to reduce the high mortality. Although there is still lack of specific biomarkers to assist the diagnosis of AMI in clinical practice, there are several biomarkers with high specificity, may become a potential tools in early diagnosis of AMI, including intestinal fatty acid binding protein (I-FABP), a-glutathione S-transferase (a-GST), D-dimer, L- and D-lactate, citrulline, ischemia modified albumin, procalcitonin (PCT). However, they use in clinical limited duo to the many studies about these makers finished with small patient populations, and heterogeneous among these populations. This review describes the etiology of AMI, the current most studied promising biomarkers, the current research situation and future of biomarker research.

Screening and combining serum biomarkers to improve their diagnostic performance in the detection of intestinal barrier dysfunction in patients after major abdominal surgery

Background

The aim of this prospective study was to screen and combine effective biomarkers to improve their diagnostic performance in detecting intestinal barrier dysfunction in patients after major abdominal surgery.

Methods

Patients undergoing major abdominal surgery were enrolled after signing informed consent in this study. The serum concentrations of α-GST, DAO, D-lactate, citrulline and I-FABP were detected 24 hours before and after surgery. The diagnostic performance of five biomarkers on intestinal barrier dysfunction was assessed using logistic regression models and receiver operating characteristic (ROC) curve analyses.

Results

Thirty-nine patients with major abdominal surgery were enrolled in and successfully completed this study. ROC analysis revealed that the sensitivities of D-lactate, citrulline and I-FABP were very high (0.91, 0.91 and 1.00, respectively), but the specificities of these biomarkers were less than 0.70. The sensitivity of DAO was very low [0.25; 95% confidence interval (CI), 0.05-0.57], but its specificity was high (0.92; 95% CI, 0.75-0.99). The accuracies of D-lactate and I-FABP were very high, and the areas under the curves (AUCs) of the biomarkers were 0.84 (95% CI, 0.68-0.93) and 0.81 (95% CI, 0.65-0.92), respectively. Different combinations of five biomarkers were also analysed. The sensitivity, specificity and AUC values of the combination of I-FABP, citrulline and D-lactate were 1.00, 0.74 and 0.89, respectively. These results were similar to those derived from the combination of α-GST, DAO, D-lactate, citrulline and I-FABP (P=1.000).

Conclusions

The combination of serum D-lactic acid, citrulline and I-FABP greatly improved the diagnostic performance for identifying intestinal barrier dysfunction in patients after major abdominal surgery.

Non-invasive Point-of-Care Device To Diagnose Acute Mesenteric Ischemia

Inadequate blood supply to the intestine can lead to acute mesenteric ischemia (AMI), with a mortality rate ranging from 60% to 90%. This high mortality rate is partially due to late detection and the lack of efficient early diagnostic tests. There is an urgent need for a point-of-care tool for immediate bedside diagnosis. Here we present for the first time a rapid and non-invasive electrochemical biosensor device based on non-faradic impedance spectroscopy to detect intestinal fatty-acid binding protein (I-FABP) as an indication of AMI. The electrochemical biosensors consist of gold interdigitated electrodes that were fabricated using photolithographic techniques on top of silicon dioxide substrates. The electrode surfaces were functionalized with an I-FABP capture antibody (CAnB) to entice the target protein, while gold nanoparticles (GNPs) functionalized with detection antibodies (DAnB-GNPs) were utilized as a novel mechanism to enhance the detection signal. Quantification of the I-FABP concentration in the medium depended on its attachment to CAnB and DAnB-GNPs in a sandwich manner, where the latter boosts the impedance signal through its binding to the I-FABP. This non-invasive non-faradic electric biosensor device demonstrates the potential for bench-to-bedside translation with the goal of decreasing morbidity and mortality from AMI.

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.

Analysis of Bowel Diseases from Blood Serum by Autofluorescence and Atomic Force Microscopy Techniques

Diagnosis of bowel diseases is often difficult and time consuming since it is not always possible to obtain adequate information by the conventional diagnostic methods to set up a diagnosis and exclude nongastrointestinal causes of symptoms. The aim of this study was to investigate the structure of blood serum samples of patients with selected intestinal diseases. The blood serum samples of patients (N=35) with selected diagnoses (mesenteric thrombosis, inflammatory bowel disease, duodenal ulcers, sepsis, enterorrhagia, sigmoid colon resection, small intestine cancer) and of healthy subjects were evaluated by synchronous fluorescence fingerprint and atomic force microscopy. Autofluorescence of blood serum studied at λex = 280 nm showed significant decrease of fluorescence intensity in patients with all types of diseases affecting bowels in comparison with the healthy control patients. The blood serum surface of ill patients showed significant differences in comparison with control group samples after atomic force microscopy evaluation as well. Irregularly placed small globular units of irregular shape in small amounts are possible to observe in patients with intestine ischemia. Fluorescence analysis and atomic force microscopy showed the ability to rapidly reflect qualitative and quantitative changes of proteins in blood serum samples of patients. These sensitive methods could be beneficial for monitoring the progression of both acute or chronic bowel diseases.

Serum lactate predicts resource utilization, but not surgical need, in the emergency department

BACKGROUND

Serum lactate is frequently tested in the emergency department (ED) setting to diagnose visceral ischemia and as a marker of end-organ perfusion. It is highly nonspecific, and levels can be affected by both kidney and liver function. In this retrospective chart review, we aim to demonstrate that serum lactate is overused in the ED setting and predicts resource utilization but not the need for surgical intervention.

METHODS

ED records with a chief complaint of "abdominal pain" were queried for the preceding 12 mo. We excluded pregnant patients, patients aged less than 18 years, and patients for whom a blood count and chemistry were not obtained. Vital signs, laboratory values, resource utilization, and outcome of the visit were obtained. Logistic regression models were developed to correct for confounding associations.

RESULTS

A total of 1003 records were obtained initially with 753 patients (75%) included in the study. Serum lactate was drawn in 118 patients (15%) and was elevated in 19 patients (16% of those drawn). Utilization of computed tomography imaging was associated with lactate utilization (P < 0.001). Patients in whom lactate was drawn were more likely to have a general surgery consult (51% versus 34%, P < 0.001) and to be admitted to the hospital (P < 0.001).

CONCLUSIONS

The use of serum lactate in the workup of patients with abdominal pain should be targeted at patients who have signs of sepsis and based on the index of suspicion for specific disease processes such as mesenteric ischemia.

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.

Urine intestinal fatty acid-binding protein predicts acute mesenteric ischemia in patients

BACKGROUND

Acute mesenteric ischemia (AMI) has a high morbidity and mortality and often presents as a diagnostic challenge. Currently, there is no blood, urine, or radiologic tests that provide a definitive diagnosis of AMI. The aim of this study was to evaluate the clinical accuracy of urine intestinal fatty acid-binding protein (I-FABP) to diagnosis AMI.

MATERIALS AND METHODS

Twenty patients referred to the Acute Care Surgery service at University of Alberta Hospital with suspected AMI taken to the operating room for definitive diagnosis were recruited. Pathologic findings from surgical specimens confirmed a gold standard diagnosis for intestinal ischemia. The patients found to be nonischemic became the internal controls. Conventional clinical markers were examined in blood including white blood cell count, lactate, and creatinine. Blood was also examined by enzyme-linked immunosorbent assays (ELISAs) for I-FABP and interleukin-6. Urine was examined preoperatively and 6 and 24 h postoperatively for I-FABP.

RESULTS

Thirteen patients were pathologically diagnosed with AMI while five patients were nonischemic; two were excluded due to missing biologic specimens. There was no difference in age or gender between ischemic and nonischemic patients (56 ± 5 versus 66 ± 11 years old, respectively; six females with ischemic and three females in the nonischemic group). There was no difference in serum lactate and creatinine between the two groups. Serum interleukin-6 levels in patients with AMI were significantly higher than nonischemic controls (0.4 ± 0.2 ng/mL versus 0.2 ± 0.07 ng/mL, respectively, P = 0.03). There was a nonstatistically significant increase in serum I-FABP in AMI patients compared to internal controls (9 ± 3 ng/mL versus 2.4 ± 0.9 ng/mL, respectively, P = 0.2). Urine I-FABP was significantly higher in patients diagnosed with AMI than in controls (7 ± 1 ng/mL versus 2 ± 1 ng/mL, respectively, P = 0.007). The receiver operating characteristic curve illustrated that urine I-FABP discriminates significantly between patients with AMI and controls (area under receiver operating characteristic = 0.88, P = 0.03).

CONCLUSIONS

The traditional clinical markers lactate and white blood cell count were not able to differentiate AMI from nonischemic bowel. However, we found that urine I-FABP was a noninvasive biomarker with high specificity and sensitivity for accurately diagnosing AMI in patients. A noninvasive accurate tool for AMI would facilitate for a rapid treatment, while preventing unnecessary surgical interventions in high-risk patient populations.

Periarrest intestinal bacterial translocation and resuscitation outcome

During the periarrest period, intestinal ischemia may result in barrier dysfunction and bacterial translocation, which has clear mechanistic links to inflammation and cascade stimulation, especially in patients who are treated with therapeutic hypothermia. Despite optimal management, periarrest bacterial translocation may worsen the outcome of cardiac arrest victims.