The Pathogenesis of Nonocclusive Mesenteric Ischemia: Implications for Research and Clinical Practice

When can we start early enteral nutrition safely in patients with shock on vasopressors?

Shock is a common critical illness characterized by microcirculatory disorders and insufficient tissue perfusion. Patients with shock and hemodynamic instability generally require vasopressors to maintain the target mean arterial pressure. Enteral nutrition (EN) is an important therapeutic intervention in critically ill patients and has unique benefits for intestinal recovery. However, the initiation of early EN in patients with shock receiving vasopressors remains controversial. Current guidelines make conservative and vague recommendations regarding early EN support in patients with shock. Increasing studies demonstrates that early EN delivery is safe and feasible in patients with shock receiving vasopressors; however, this evidence is based on observational studies. Changes in gastrointestinal blood flow vary by vasopressor and inotrope and are complex. The risk of gastrointestinal complications, especially the life-threatening complications of non-occlusive mesenteric ischemia and non-occlusive bowel necrosis, cannot be ignored in patients with shock during early EN support. It remains a therapeutic challenge in critical care nutrition therapy to determine the initiation time of EN in patients with shock receiving vasopressors and the safe threshold region for initiating EN with vasopressors. Therefore, the current review aimed to summarize the evidence on the optimal and safe timing of early EN initiation in patients with shock receiving vasopressors to improve clinical practice.

Luminal Delivery of Pectin-Modified Oxygen Microbubbles Mitigates Rodent Experimental Intestinal Ischemia

INTRODUCTION

Ischemic gut injury is common in the intensive care unit, impairs gut barrier function, and contributes to multiorgan dysfunction. One novel intervention to mitigate ischemic gut injury is the direct luminal delivery of oxygen microbubbles (OMB). Formulations of OMB can be modified to control the rate of oxygen delivery. This project examined whether luminal delivery of pectin-modified OMB (OMBp5) can reduce ischemic gut injury in a rodent model.

METHODS

The OMBp5 formulation was adapted to improve delivery of oxygen along the length of small intestine. Adult Sprague-Dawley rats (n = 24) were randomly allocated to three groups: sham-surgery (SS), intestinal ischemia (II), and intestinal ischemia plus luminal delivery of OMBp5 (II + O). Ischemia-reperfusion injury was induced by superior mesenteric artery occlusion for 45 min followed by reperfusion for 30 min. Outcome data included macroscopic score of mucosal injury, the histological score of gut injury, and plasma biomarkers of intestinal injury.

RESULTS

Macroscopic, microscopic data, and intestinal injury biomarker results demonstrated minimal intestinal damage in the SS group and constant damage in the II group. II + O group had a significantly improved macroscopic score throughout the gut mucosa (P = 0.04) than the II. The mean histological score of gut injury for the II + O group was significantly improved on the II group (P ≤ 0.01) in the proximal intestine only, within 30 cm of delivery. No differences were observed in plasma biomarkers of intestinal injury following OMBp5 treatment.

CONCLUSIONS

This proof-of-concept study has demonstrated that luminal OMBp5 decreases ischemic injury to the proximal small intestine. There is a need to improve oxygen delivery over the full length of the intestine. These findings support further studies with clinically relevant end points, such as systemic inflammation and vital organ dysfunction.

Mesenteric ischemia in the acute care setting

ABSTRACT

Mesenteric ischemia is a group of disorders requiring prompt identification, supportive care, and treatment. Chronic mesenteric ischemia can develop into acute mesenteric ischemia, which has high mortality. Acute mesenteric ischemia can be occlusive (caused by arterial embolism, arterial thrombosis, or mesenteric venous thrombosis) or nonocclusive, with treatment depending on the underlying cause.

Identification of Perioperative Procedural and Hemodynamic Risk Factors for Developing Colonic Ischemia after Ruptured Infrarenal Abdominal Aortic Aneurysm Surgery: A Single-Centre Retrospective Cohort Study

(1) Background: This retrospective study evaluated perioperative and intensive care unit (ICU) variables to predict colonic ischemia (CI) after infrarenal ruptured abdominal aortic aneurysm (RAAA) surgery. (2) Materials and Methods: We retrospectively analyzed the data of the patients treated for infrarenal RAAA from January 2011 to December 2020 in our hospital. (3) Results: A total of 135 (82% male) patients were admitted to ICU after treatment of infrarenal RAAA. The median age of all patients was 75 years (IQR 68-81 years). Of those, 24 (18%) patients developed CI, including 22 (92%) cases within the first three postoperative days. CI was found more often after open repair compared to endovascular treatment (22% vs. 5%, p = 0.021). Laboratory findings in the first seven PODs revealed statistically significant differences between CI and non-CI patients for serum lactate, minimum pH, serum bicarbonate, and platelet count. Norepinephrine (NE) was used in 92 (68%) patients during ICU stay. The highest daily dose of norepinephrine was administered to CI patients at POD1. Multivariable analysis revealed that NE > 64 µg/kg (RD 0.40, 95% CI: 0.25-0.55, p < 0.001), operating time ≥ 200 min (RD 0.18, 95% CI: 0.05-0.31, p = 0.042), and pH < 7.3 (RD 0.21, 95% CI: 0.07-0.35, p = 0.019), significantly predicted the development of CI. A total of 23 (17%) patients died during the hospital stay, including 8 (33%) patients from the CI group and 15 (7%) from the non-CI group (p = 0.032). (4) Conclusions: CI after RAAA is a sever complication occurring most frequently within the first 3 postoperative days. Our study identified many surrogate markers associated with colonic ischemia after aortic RAAA, including norepinephrine dose > 64 µg/kg, operating time ≥ 200 min, and PH < 7.3. Future studies are needed to support these results.

Mesenteric ischemia in the acute care setting

ABSTRACT

Mesenteric ischemia is a group of disorders requiring prompt identification, supportive care, and treatment. Chronic mesenteric ischemia can develop into acute mesenteric ischemia, which has high mortality. Acute mesenteric ischemia can be occlusive (caused by arterial embolism, arterial thrombosis, or mesenteric venous thrombosis) or nonocclusive, with treatment depending on the underlying cause.

Risk factors for postoperative disseminated intravascular coagulation in surgical patients with non-occlusive mesenteric ischemia

PURPOSE

The prognostic impact of disseminated intravascular coagulation (DIC) in surgical patients with non-occlusive mesenteric ischemia (NOMI) is unclear. This study aimed to confirm the association between postoperative DIC and prognosis and to identify preoperative risk factors associated with postoperative DIC.

METHODS

This retrospective study included 52 patients who underwent emergency surgery for NOMI between January 2012 and March 2022. Kaplan-Meier curve analysis with the log-rank test was used to compare 30-day survival and hospital survival between patients with and without postoperative DIC. In addition, univariable and multivariable logistic regression analyses were performed to identify the preoperative risk factors for postoperative DIC.

RESULTS

The 30-day and hospital mortality rates were 30.8% and 36.5%, respectively, and the incidence rate of DIC was 51.9%. Compared to patients without DIC, patients with DIC showed significantly lower rates of 30-day survival (41.5% vs 96%, log-rank P < 0.001) and hospital survival (30.2% vs 86.4%, log-rank, P < 0.001). Logistic regression analyses showed that the Japanese Association for Acute Medicine (JAAM) DIC score (OR = 2.697; 95% CI, 1.408-5.169; P = 0.003) and Sequential Organ Failure Assessment (SOFA) score (OR = 1.511; 95% CI, 1.111-2.055; P = 0.009) were independent risk factors for postoperative DIC in surgical patients with NOMI.

CONCLUSION

The development of postoperative DIC is a significant prognostic factor for 30-day and hospital mortalities in surgical patients with NOMI. In addition, the JAAM DIC score and SOFA score have a high discriminative ability for predicting the development of postoperative DIC.

A Case of Colchicine Toxicity Presenting With Euglycemic Diabetic Ketoacidosis

Colchicine has a narrow therapeutic window and a high risk of toxicity when co-administered with CYP3A4 inhibitors and P-glycoprotein inhibitors. Colchicine toxicity is associated with various metabolic disturbances and can cause multiorgan failure and death. However, to our knowledge, there are no documented reports of colchicine toxicity initially presenting as euglycemic diabetic ketoacidosis (DKA). We present a case of colchicine toxicity with concomitant euglycemic DKA in a man with long-term colchicine use who was also prescribed clarithromycin and dapagliflozin.

Intraluminal oxygen mitigates acute mesenteric ischaemia: a systematic review of methods and outcomes in animal studies

BACKGROUND

Acute Mesenteric Ischaemic (AMI) is a rare condition with significant morbidity and mortality. Many causes of AMI exist, which usually begin with mucosal injury. Onset is insiduous and there is frequent diagnostic delay. Current treatments can only control established injury and prevent propagation, hence new interventions are needed. The prevention and treatment of AMI by intraluminal delivery of oxygen has yet to be investigated in the clinical setting. This article aims to systemically review experimental studies investigating this novel therapy.

METHODS

Following the PRISMA guidelines, searches of PubMed and Ovid MEDLINE databases were performed up to June 2022. Two independent investigators extracted the data.

RESULTS

There were 20 experimental studies, 16 of which used an occlusive ischaemia reperfusion model. Six different formulations were used to deliver intraluminal oxygen, with perflurocarbon being the most common. Studies consistently showed local and systemic benefits. Intraluminal oxygen therapy improved histological severity of mucosal injury in all studies when oxygen was delivered during the ischaemia phase, but could cause harm if given during the reperfusion phase. Improvement was also demonstrated in endpoints assessing intestinal function, biomarkers of intestinal damage, measures of systemic physiological derangement and mortality.

CONCLUSION

Intraluminal oxygenation appears to be an effective treatment for AMI. There remain significant questions regarding optimal timing and delivery formulation before clinical translation of this treatment strategy.

Increased blood lactate during enteral nutrition in the critically ill: associations and treatment options

PURPOSE OF REVIEW

To evaluate the significance of blood lactate increase during enteral nutrition in the critically ill, and to propose diagnostic and therapeutic strategies.

RECENT FINDINGS

Acute mesenteric ischemia occurs in approximately 1% of critically ill patients treated with catecholamine. Recent literature suggests that enteral nutrition is a risk factor of acute mesenteric ischemia, in particular in case of low cardiac output, by a mechanism of nonocclusive mesenteric ischemia. The association of clinical, biological, and computed tomography imaging might help to evaluate the reversibility of acute mesenteric ischemia.

SUMMARY

As enteral nutrition induces an increased metabolic work of the gut, the inadequation between oxygen delivery and demand exposes the gut to a phenomenon of nonocclusive mesenteric ischemia. Before initiation of enteral nutrition,, and before each increase of the enteral nutrition dose, the risk factors of nonocclusive mesenteric ischemia should be searched in order to prevent it. While under enteral nutrition, increased lactate concentration while receiving enteral nutrition requires the urgent search for nonocclusive mesenteric ischemia, and the adaptation of enteral nutrition (reduction, stop, and/or switch to parenteral nutrition or tolerate early nutrient restriction). Early signs of nonocclusive mesenteric ischemia should be searched in order to allow for a rapid diagnosis, before development of irreversible transmural necrosis. After the diagnosis of acute mesenteric ischemia, improving the balance between oxygen demand and delivery to the gut, evaluating the reversibility of the gut ischemia, and performing urgent resection in case of irreversible transmural necrosis should be the main objectives. After the resolution of acute mesenteric ischemia, the benefit risk analysis of enteral nutrition reintroduction should be evaluated.

An Update on Acute Mesenteric Ischemia

Acute mesenteric ischemia (AMI) is an uncommon yet highly lethal cause of acute abdomen in the emergency setting. Computed tomography (CT) imaging, in particular a biphasic protocol consisting of angiographic and venous phase scans, is widely used to corroborate non-specific clinical findings when suspicions of AMI are high. Techniques such as low kilovoltage peak scanning, dual energy acquisition, or a combined arterial/enteric phase can improve iodine conspicuity and evaluation of bowel enhancement. Biphasic CT with CT angiography is mandatory to directly assess for the 3 primary etiologies of AMI-arterial, venous, and non-occlusive mesenteric ischemia (NOMI), and the CT angiographic findings may be the first visible in the disease. In addition, numerous non-vascular CT findings have also been reported. Bowel wall thickening, mesenteric stranding, and ascites are common but non-specific findings that correlate poorly with disease severity. Pneumatosis intestinalis and portomesenteric venous gas, while not pathognomonic for ischemia, are highly specific in cases of high clinical suspicion. Bowel wall hypoenhancement is an early and specific sign but requires a protocol optimizing iodine conspicuity to confidently identify. Finally, intraperitoneal free air and solid organ infarcts are also highly specific ancillary findings in AMI. AMI occurs as a complication in 10% of small bowel obstruction (SBO) patients, and understanding imaging findings of ischemia in the context of SBO is necessary to aid in treatment planning and reduce over- and under-diagnosis of strangulation. Familiarity with the imaging features of ischemia by radiologists is vital to establish an early diagnosis before irreversible necrosis occurs.

Acute mesenteric ischemia due to percutaneous coronary intervention: A case report

BACKGROUND

Percutaneous coronary intervention (PCI) is extensively used to treat acute coronary syndromes (ACS). Acute mesenteric ischemia is a life-threatening disease if untreated.

CASE SUMMARY

An 81-year-old female presented with 3 d of lethargy and 1 d of dyspnea. On November 16, 2021, the patient developed a coma. Her oxygen saturation dropped to 70%-80%, the patient was admitted to the intensive care unit for further treatment. Chest computed tomography (CT) showed chronic bronchitis, emphysema, and multiple lung infections. Abdominal CT scan showed no obvious abnormalities, but have severely calcified abdominal vessels. The patient received assisted ventilation, and vasoactive, and anti-infection drugs. Troponin level was elevated. Since the patient was in a coma, it could not be determined whether she had chest pain. The cardiologist assumed that the patient had developed ACS; therefore, the patient underwent PCI via the left femoral artery approach, and no obvious abnormalities were found in the left and right coronary arteries. On the second postoperative day, the patient presented with abdominal distension and decreased bowel sounds; constipation was considered and a glycerin enema was administered. On day 4, the patient suddenly lost consciousness, and had decreased blood pressure, abdominal wall swelling with increased tension, and absence of bowel sounds. An urgent abdominal CT scan revealed gas in her hepatic portal system with extensive bowel wall necrosis. The patient died on day 5 due to intractable shock.

CONCLUSION

The potential serious complications in patients undergoing PCI, especially the patients who are hemodynamically unstable and have severely calcified abdominal vessels, should all be considered.

Mesenteric Ischemia in a Patient with Essential Thrombocythemia: Does COVID-19 Play Any Role? A Case Report and Overview of the Literature

Introduction: Chronic mesenteric ischemia is a rare entity with non-specific symptomatology; combined with rare etiologies, it could lead to unwarranted surgical indication. Case report: We report the case of an 85-year-old woman, with a history of hypertension, persistent thrombocytosis, atherosclerosis, and recent minor COVID-19 infection, presenting to the hospital with postprandial abdominal pain and nonspecific clinical examination findings; upon abdominal CT, superior mesenteric artery circumferential thrombosis was revealed. A bone marrow biopsy was performed due to suspected essential thrombocythemia, confirming the diagnosis. An endovascular approach was chosen as therapy option and a stent was placed in the occluded area. Dual antiplatelet and cytoreductive therapies were initiated after the intervention. Clinical course was excellent, with no residual stenosis 1 month after stenting. Conclusions: The therapeutic strategy in elderly patients with exacerbated chronic mesenteric ischemia requires an interdisciplinary approach in solving both the exacerbation and the underlying conditions in order to prevent further thrombotic events. Although the patient presented a thrombotic state, other specific risk factors such as COVID-19 related-coagulopathy and essential thrombocythemia should be considered.

Prognostic factors for the successful conservative management of nonocclusive mesenteric ischemia

Background

The criteria for deciding upon non-operative management for nonocclusive mesenteric ischemia (NOMI) are poorly defined. The aim of this study is to determine the prognostic factors for survival in conservative treatment of NOMI.

Methods

Patients with bowel ischemia were identified by searching for “ICD-10 code K550” in the Diagnosis Procedure Combination database between June 2015 and May 2020. A total of 457 patients were extracted and their medical records, including the clinical factors, imaging findings and outcomes, were analyzed retrospectively. Diagnosis of NOMI was confirmed by the presence of specific findings in contrast-enhanced multidetector-row CT. Twenty-six patients with conservative therapy for NOMI, including four cases of explorative laparotomy or laparoscopy, were enrolled.

Results

Among the 26 cases without surgical intervention, eight patients (31%) survived to discharge. The level of albumin was significantly higher, and the levels of lactate dehydrogenase, total bilirubin, C-reactive protein, and lactate were significantly lower in the survivors than the non-survivors. Sepsis-related Organ Failure Assessment (SOFA) score was significantly lower in the survivors than the non-survivors. The most reliable predictor of survival for NOMI was SOFA score (cutoff value ≤ 3 points), which had the highest AUC value (0.899) with odds ratio of 0.075 (CI: 0.0096–0.58).

Conclusions

The SOFA score and several biological markers are promising predictors to determine a treatment plan for NOMI and to avoid unnecessary laparotomy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13017-022-00436-w.

Nonocclusive mesenteric ischemia caused by type B aortic dissection: a case report

Background

Nonocclusive mesenteric ischemia (NOMI) is defined as acute intestinal ischemia because of decreased blood flow in mesenteric vessels. Only a few cases of NOMI that occur secondary to aortic dissection (AD) have been reported, resulting in the lack of sufficient knowledge of diagnosis and treatment.

Case presentation

We aimed to report a case of NOMI caused by type B Aortic Dissection. A 26-year-old male patient was transferred to our hospital with the diagnose of NOMI and aortic dissection in April 2018. The abdominal computed tomography (CT) assists the diagnosis of paralytic intestinal obstruction, intestinal wall pneumatosis, and perforation. Emergency laparotomy revealed that the bowel wall supplied by the superior mesenteric artery (SMA) was pale with the palpable but weak pulsation of the parietal artery. The small intestine was extremely dilated with a paper-thin, fragile wall that was ruptured easily and could not be sutured. In this case, extensive resection and segmental drainage were done. Postoperatively, the digestive tract was reconstructed. However, the patient suffered from iron deficiency anemia and short bowel syndrome eight months later, and unfortunately died from long-term complications.

Conclusion

Aortic dissection leads to continuous decrease in blood pressure and blood flow to the SMA, considering as a predisposing factor for NOMI. During the treatment, extensive resection and segmental drainage are the optimal surgical strategy, which can make benefit in emergencies especially.

Mimics of Crohn's Disease

Crohn's disease is a chronic inflammatory disease that can affect any portion of the gastrointestinal tract. Associated symptoms can vary based on the severity of disease, extent of involvement, presence of extraintestinal manifestations, and development of complications. Diagnosis is based on a constellation of findings. Many diseases can mimic Crohn's disease and lead to diagnostic conundrums. These include entities associated with the gastrointestinal luminal tract, vascular disease, autoimmune processes, various infections, malignancies and complications, drug- or treatment-induced conditions, and genetic diseases. Careful consideration of possible causes is necessary to establish the correct diagnosis.

Improving nutrition practices for postoperative high-risk heart transplant and ventricular assist device implant patients in circulatory compromise: A quality improvement pre- and post-protocol intervention outcome study

BACKGROUND

Patients undergoing heart transplant (HT) and ventricular assist device (VAD) implant may experience intra- and postoperative complications requiring high-dose vasopressor agents and/or mechanical circulatory support. These complications increase the risk of nonocclusive bowel ischemia (NOBI) and inadequate enteral nutrition (EN) delivery, and guidance for this high-risk patient population is limited. To optimize nutrition support practices in this patient population at our institution, we created the High-Risk Nutrition Support Protocol (HRNSP) to improve nutrient delivery and promote safer EN practices in the setting of NOBI risk factors after HT and VAD implant.

METHODS

We developed and implemented a nutrition support protocol as a quality improvement (QI) initiative. Data were obtained before (n = 62) and after (n = 52) protocol initiation. We compared nutrition and clinical outcomes between the pre- and post-intervention groups.

RESULTS

Fewer calorie deficits (P < 0.001), fewer protein deficits (P < 0.001), a greater proportion of calorie/protein needs met (P < 0.001), zero NOBI cases (0%), and decreased intensive care unit (ICU) length of stay (LOS) (P = 0.005) were observed with 100% (n = 52 of 54) HRNSP implementation success. Increased use of parenteral nutrition did not increase central line-associated bloodstream infections (P = 0.46). There was no difference in hospital LOS (P = 0.44) or 90-day and 1-year mortality (P = 0.56, P = 0.35).

CONCLUSION

This single-center, QI pre- and post-protocol intervention outcome study suggests that implementing and adhering to a nutrition support protocol for VAD implant/HT patients with hemodynamic complications increases nutrient delivery and is associated with reduced ICU LOS and NOBI.

Predictors of response to intra-arterial vasodilatory therapy of non-occlusive mesenteric ischemia in patients with severe shock: results from a prospective observational study

BACKGROUND

Non-occlusive mesenteric ischemia (NOMI) is a life-threatening condition occurring in patients with shock and is characterized by vasoconstriction of the mesenteric arteries leading to intestinal ischemia and multi-organ failure. Although minimal invasive local intra-arterial infusion of vasodilators into the mesenteric circulation has been suggested as a therapeutic option in NOMI, current knowledge is based on retrospective case series and it remains unclear which patients might benefit. Here, we prospectively analyzed predictors of response to intra-arterial therapy in patients with NOMI.

METHODS

This is a prospective single-center observational study to analyze improvement of ischemia (indicated by reduction of blood lactate > 2 mmol/l from baseline after 24 h, primary endpoint) and 28-day mortality (key secondary endpoint) in patients with NOMI undergoing intra-arterial vasodilatory therapy. Predictors of response to therapy concerning primary and key secondary endpoint were identified using a) clinical parameters as well as b) data from 2D-perfusion angiography and c) experimental biomarkers of intestinal injury.

RESULTS

A total of 42 patients were included into this study. At inclusion patients had severe shock, indicated by high doses of norepinephrine (NE) (median (interquartile range (IQR)) 0.37 (0.21-0.60) μg/kg/min), elevated lactate concentrations (9.2 (5.2-13) mmol/l) and multi-organ failure. Patients showed a continuous reduction of lactate following intra-arterial prostaglandin infusion (baseline: (9.2 (5.2-13) mmol/l vs. 24 h: 4.4 (2.5-9.1) mmol/l, p < 0.001) with 22 patients (52.4%) reaching a lactate reduction > 2 mmol/l at 24 h following intervention. Initial higher lactate concentrations and lower NE doses at baseline were independent predictors of an improvement of ischemia. 28-day mortality was 59% in patients with a reduction of lactate > 2 mmol/l 24 h after inclusion, while it was 85% in all other patients (hazard ratio 0.409; 95% CI, 0.14-0.631, p = 0.005).

CONCLUSIONS

A reduction of lactate concentrations was observed following implementation of intra-arterial therapy, and lactate reduction was associated with better survival. Our findings concerning outcome predictors in NOMI patients undergoing intra-arterial prostaglandin therapy might help designing a randomized controlled trial to further investigate this therapeutic approach. Trial registration Retrospectively registered on January 22, 2020, at clinicaltrials.gov (REPERFUSE, NCT04235634), https://clinicaltrials.gov/ct2/show/NCT04235634?cond=NOMI&draw=2&rank=1 .

Enteral Nutrition in Critically Ill Patients Under Vasoactive Drug Therapy. The NUTRIVAD Study

BACKGROUND

Enteral nutrition (EN) in critically ill patients requiring vasoactive drug (VAD) support is controversial. This study assesses the tolerability and safety of EN in such patients.

METHODS

This prospective observational study was conducted in 23 ICUs over 30 months. Inclusion criteria were a need for VAD and/or mechanic circulatory support (MCS) over a minimum of 48 h, a need for at least 48 h of mechanical ventilation, an estimated life expectancy longer than 72 h, and at least 72 h of ICU stay. Patients with refractory shock were excluded. EN was performed according to established protocols during which descriptive, daily hemodynamic and efficacy and safety data were collected. An independent research group conducted the statistical analysis.

RESULTS

Of 200 patients included, 30 (15%) required MCS and 145 (73%) met early multiorgan dysfunction criteria. Mortality was 24%. Patients needed a mean dose of norepinephrine in the first 48 h of 0.71 μg/kg/min (95%CI: 0.63-0.8) targeting a mean arterial pressure of 68 mmHg (95%CI: 67-70) during the first 48 h. EN was started 34 h (95%CI: 31-37) after ICU admission. Mean energy and protein delivered by EN/patient/day were 1159 Kcal (95%CI: 1098-1220) and 55.6 g (52.4-58.7) respectively. Daily energy balance during EN/patient/day was -432 (95%CI: -496 to -368). 154 (77%) patients experienced EN-related complications. However, severe complications such as mesenteric ischemia were recorded in only 1 patient (0.5%).

CONCLUSIONS

EN in these patients seems feasible, safe and unrelated to serious complications. Reaching the energy target only through EN is difficult.

CLINICAL RELEVANCY STATEMENT

Enteral nutrition (EN) in critically ill patients requiring vasoactive drugs (VAD) is currently a subject of controversy. Factors such as when to start EN, dosing, monitoring, or whether to avoid EN altogether are a real challenge because of its link to a risk of bowel ischemia. We describe our experience with EN in 200 critically ill patients on mechanical ventilation and requiring VAD. Under adequate supervision, EN proved feasible and safe. Our findings require confirmation in clinical intervention trials. This article is protected by copyright. All rights reserved.

Non-occlusive mesenteric ischemia during acute stroke management: three case reports

Background

There are many reports of non-occlusive mesenteric ischemia in patients on maintenance hemodialysis and following cardiac surgery. However, there are few reports of non-occlusive mesenteric ischemia in patients with acute stroke.

Case presentation

We report three cases of non-occlusive mesenteric ischemia with onset during treatment for acute stroke. All of the patients were undergoing strict blood-pressure control, and two patients developed NOMI soon after tracheostomy when enteral nutrition had been resumed.

Conclusion

Many stroke patients are older adults with risk factors such as arteriosclerosis. Thus, during acute stroke management, there is a possibility that patients may develop non-occlusive mesenteric ischemia due to decreased intestinal blood flow secondary to strict blood-pressure control. This case report implicates early enteral nutrition as a potential etiopathogenic factor of non-occlusive mesenteric ischemia in patients with acute stroke.

Factors associated with acute mesenteric ischemia among critically ill ventilated patients with shock: a post hoc analysis of the NUTRIREA2 trial

PURPOSE

Acute mesenteric ischemia (AMI) is a rare, but life-threatening condition occurring among critically ill patients. Several factors have been associated with AMI, but the causal link is debated, most studies being retrospective. Among these factors, enteral nutrition (EN) could be associated with AMI, in particular among patients with shock. We aimed to study the factors independently associated with AMI in a post hoc analysis of the NUTRIREA-2 trial including 2410 critically ill ventilated patients with shock, randomly assigned to receive EN or parenteral nutrition (PN).

METHODS

Post hoc analysis of the NUTRIREA-2 trial was conducted. Ventilated adults with shock were randomly assigned to receive EN or PN. AMI was assessed by computed tomography, endoscopy, or laparotomy. Factors associated with AMI were studied by univariate and multivariate analysis.

RESULTS

2410 patients from 44 French intensive care units (ICUs) were included in the study: 1202 patients in the enteral group and 1208 patients in the parenteral group. The median age was 67 [58-76] years, with 67% men, a SAPS II score of 59 [46-74], and a medical cause for ICU admission in 92.7%. AMI was diagnosed among 24 (1%) patients, mainly by computed tomography (79%) or endoscopy (38%). The mechanism of AMI was non-occlusive mesenteric ischemia (n = 12), occlusive (n = 4), and indeterminate (n = 8). The median duration between inclusion in the trial and AMI diagnosis was 4 [1-11] days. Patients with AMI were older, had a higher SAPS II score at ICU admission, had higher plasma lactate, creatinine, and ASAT concentrations and lower hemoglobin concentration, had more frequently EN, dobutamine, and CVVHDF at inclusion, developed more frequently bacteremia during ICU stay, and had higher 28-day and 90-day mortality rates compared with patients without AMI. By multivariate analysis, AMI was independently associated with EN, dobutamine use, SAPS II score ≥ 62 and hemoglobin concentration ≤ 10.9 g/dL.

CONCLUSION

Among critically ill ventilated patients with shock, EN, dobutamine use, SAPS II score ≥ 62 and hemoglobin ≤ 10.9 g/dL were independently associated with AMI. Among critically ill ventilated patients requiring vasopressors, EN should be delayed or introduced cautiously in case of low cardiac output requiring dobutamine and/or in case of multiple organ failure with high SAPS II score.

Non-Occlusive Mesenteric Ischemia in Children With Diabetic Ketoacidosis: Case Report and Review of Literature

INTRODUCTION

Despite the use of technology, recurrent diabetic ketoacidosis (DKA) prevention remains an unmet need in children and adolescents with T1D and may be accompanied by life-threatening acute complications. We present a rare case of non-occlusive mesenteric ischemia (NOMI) with overt manifestation after DKA resolution and a discussion of recent literature addressing DKA-associated NOMI epidemiology and pathogenesis in children and adolescents.

CASE PRESENTATION

A 13-year-old female with previously diagnosed T1D, was admitted at our emergency department with hypovolemic shock, DKA, hyperosmolar state and acute kidney injury (AKI). Mildly progressive abdominal pain persisted after DKA correction and after repeated ultrasound evaluations ultimately suspect for intestinal perforation, an intraoperative diagnosis of NOMI was made.

CONCLUSION

The diagnosis of DKA-associated NOMI must be suspected in pediatric patients with DKA, persistent abdominal pain, and severe dehydration even after DKA resolution.

The intensivist's assessment of gastrointestinal function: A pilot study

Gastrointestinal dysfunction/failure (GDF) is a common cause of concern in critically ill patients. Although the gut plays an important role in the genesis of organ failure, its exclusion from organ severity scoring systems has made it challenging for intensivists to score it sufficiently at the bedside. We aimed to survey intensive care specialists about their perceptions, attitudes, and approaches towards the assessment of the gut in Australia and New Zealand intensive care units (ICUs). An electronic (online) questionnaire was used to survey intensive care specialists from the Australia and New Zealand Intensive Care Society (ANZICS). The survey comprised 10 questions focused on four key areas: (i) the extent of the problem with GDF in ICUs, (ii) the use and reliability of the current gut scoring tools, (iii) personal approaches and practices associated with GDF assessment, and (4) potential value of a novel GDF scoring system and its incorporation into an organ severity score. Our results showed that GDF was a significant concern amongst ICUs in Australia and New Zealand intensivists (84%; 66/79), with a small number of participants (14%; 3/79) using a gut scoring tool in their ICUs. Despite this, we have no established objective scoring tool for its assessment. The survey highlighted the need for developing a novel scoring tool to assess the gut was considered important amongst majority of the intensivists (92%; 72/78), which would prove useful in clinical practice and potentially lead to incorporation into an organ severity score in the future.

Effect of Surgical Technique on the Microstructure and Microcirculation of the Small Intestine Stump during Delayed Anastomosis: Multimodal OCT Data

The aim of the study was to use multimodal optical coherence tomography (MM OCT) to evaluate microstructure and microcirculation in the proximal and distal sections of the intestine relative to the resected area in acute mesenteric ischemia.

Avoiding Misdiagnosis of Abdominal Vascular Catastrophes

Abdominal vascular emergencies are an uncommon entity in emergency medicine, but when they present, they are often catastrophic. These time-sensitive and life-threatening diagnoses are often hidden in nonspecific complaints such as nausea, vomiting, or flank pain, so the emergency physician must remain diligent and consider these in the differential diagnoses. The following is an overview of the more common of these abdominal vascular emergencies, in the hope that they help the Emergency Physician avoid the misdiagnosis and subsequent vascular catastrophe that would follow.

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.

The additional use of methylene blue has a decatecholaminisation effect on cardiac vasoplegic syndrome after cardiac surgery

Background

Postoperative vasoplegia with minimal responsiveness to vasopressors is common after cardiac surgery. Called cardiac vasoplegic syndrome (CVS), it is caused by multiple factors. Treating CVS involves a high dose of fluids and catecholamines, however high doses of catecholamines and fluids are associated with serious side effects. There is evidence that new therapeutic strategies can lead to a reduction in norepinephrine doses and mortality in CVS. Specifically, the use of non-adrenergic vasopressors such as methylene blue (MB) can be beneficial.

Methods

We retrospectively analyzed the electronic records of 8716 adult cardiac surgery patients from November 2008 to December 2016. Medication, hemodynamic and outcome parameter data were analyzed for CVS until discharge. We determined CVS according to the following parameters: a postoperative onset of ≤24 h, a reduced mean arterial pressure (MAP) of < 70 mmHg, a dose of norepinephrine ≥0.8 mg*h^− 1 and a continuously increasing need for catecholamine, without ventricular dysfunction.

Results

We identified 513 patients with CVS. Perioperative risk factors were higher in patients treated with methylene blue (MB). Before MB administration patients had a significantly higher dose of norepinephrine, and MAP increased after MB administration. Norepinephrine could be reduced after MB administration and MAP remained stable at the same level even after the reduction of norepinephrine.

Conclusions

CVS patients have a severe systemic disease accompanied by significant operative stress and a high catecholamine requirement. The administration of MB in addition to standard treatment for CVS in the first 24 h was accompanied by an increase in MAP followed by a decrease in vasopressor requirement, indicating that early MB administration can be beneficial.

Maintaining oxygen delivery is crucial to prevent intestinal ischemia in critical ill patients

Background

Intestinal ischemia is a common complication with obscure pathophysiology in critically ill patients. Since insufficient delivery of oxygen is discussed, we investigated the influence of oxygen delivery, hemoglobin, arterial oxygen saturation, cardiac index and the systemic vascular resistance index on the development of intestinal ischemia. Furthermore, we evaluated the predictive power of elevated lactate levels for the diagnosis of intestinal ischemia.

Methods

In a retrospective case-control study data (mean oxygen delivery, minimum oxygen delivery, systemic vascular resistance index) of critical ill patients from 02/2009–07/2017 were analyzed using a proportional hazard model. General model fit and linearity were tested by likelihood ratio tests. The components of oxygen delivery (hemoglobin, arterial oxygen saturation and cardiac index) were individually tested in models.

Results

59 out of 874 patients developed intestinal ischemia. A mean oxygen delivery less than 250ml/min/m² (LRT vs. null model: p = 0.018; LRT for non-linearity: p = 0.012) as well as a minimum oxygen delivery less than 400ml/min/m² (LRT vs null model: p = 0.016; LRT for linearity: p = 0.019) were associated with increased risk of the development of intestinal ischemia. We found no significant influence of hemoglobin, arterial oxygen saturation, cardiac index or systemic vascular resistance index. Receiver operating characteristics analysis for elevated lactate levels, pH, CO₂ and central venous saturation was poor with an area under the receiver operating characteristic of 0.5324, 0.52, 0.6017 and 0.6786.

Conclusion

There was a significant correlation for mean and minimum oxygen delivery with the incidence of intestinal ischemia for values below 250ml/min/m² respectively 400ml/min/m². Neither hemoglobin, arterial oxygen saturation, cardiac index, systemic vascular resistance index nor elevated lactate levels could be identified as individual risk factors.

Vasodilator Therapy and Mortality in Nonocclusive Mesenteric Ischemia: A Nationwide Observational Study. Crit Care Med. 2020;48:e356-e361. [PMID: 32044841 DOI: 10.1097/ccm.0000000000004255]

OBJECTIVES

Previous studies have suggested that vasodilator therapy may be beneficial for patients with nonocclusive mesenteric ischemia. However, robust evidence supporting this contention is lacking. We examined the hypothesis that vasodilator therapy may be effective in patients diagnosed with nonocclusive mesenteric ischemia.

DESIGN

Retrospective cohort study.

SETTING

The Japanese Diagnosis Procedure Combination inpatient database.

PATIENTS

A total of 1,837 patients with nonocclusive mesenteric ischemia from July 2010 to March 2018.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We compared patients who received vasodilator therapy (vasodilator group; n = 161) and those who did not (control group; n = 1,676) using one-to-four propensity score matching. Vasodilator therapy was defined as papaverine and/or prostaglandin E1 administered via venous and/or arterial routes within 2 days of admission. Only patients who did not receive abdominal surgery within 2 days of admission were analyzed. The main outcomes were in-hospital mortality and abdominal surgery performed greater than or equal to 3 days after admission. After propensity score matching, in-hospital mortality was significantly lower in the vasodilator group (risk difference, -11.6%; p = 0.005). The proportion of patients who received abdominal surgery at greater than or equal to 3 days after admission was also significantly lower in the vasodilator group (risk difference, -10.2%; p = 0.002).

CONCLUSIONS

Vasodilator therapy with papaverine and/or prostaglandin E1 is associated with lower in-hospital mortality and prevalence of abdominal surgery in patients with nonocclusive mesenteric ischemia.

Nonocclusive mesenteric ischemia secondary to spinal cord injury: an autopsy case

INTRODUCTION

Spinal cord injury (SCI) is a major direct cause of accidental death. Cervical SCI can lead to death in a short time period by neurogenic shock. Prompt vasopressor administration is recommended for patients with SCI accompanied by hypotension (systolic blood pressure < 90 mmHg). We herein present the first fatal case of nonocclusive mesenteric ischemia (NOMI) secondary to cervical SCI in a patient who suddenly died 1 week after an accidental fall.

CASE PRESENTATION

A 72-year-old man without medical history of cardiovascular disease suffered tetraplegia with a neurological level at C4 after a fall accident. He was fully conscious with stable respiratory ability, and the systolic blood pressure was maintained at >90 mmHg without vasopressor agents. High fever occurred 7 days after the accident and he died in the next morning. Autopsy revealed segmental intestinal necrosis from the ileum to the ascending colon, without mesenteric embolism, or severe arteriosclerosis.

DISCUSSION

This case implies that maintenance of >90-mmHg systolic blood pressure can insufficiently keep the blood flow to prevent NOMI, and the mean arterial blood pressure of >85 mmHg can be more plausible as suggested in the guideline. Monitoring the mean arterial blood pressure in acute SCI is useful not only for neurological recovery but also for the maintenance of vital intestinal perfusion.

Many faces of acute bowel ischemia: overview of radiologic staging

Acute bowel ischemia (ABI) can be life threatening with high mortality rate. In spite of the advances made in diagnosis and treatment of ABI, no significant change has occurred in the mortality over the past decade. ABI is potentially reversible with prompt diagnosis. The radiologist plays a central role in the initial diagnosis and preventing progression to irreversible intestinal ischemic injury or bowel necrosis. The most single imaging findings described in the literature are either non-specific or only present in the late stages of ABI, urging the use of a constellation of features to reach a more confident diagnosis. While ABI has been traditionally categorized based on the etiology with a wide spectrum of imaging findings overlapped with each other, the final decision for patient’s management is usually made on the stage of the ABI with respect to the underlying pathophysiology. In this review, we first discuss the pathologic stages of ischemia and then summarize the various imaging signs and causes of ABI. We also emphasize on the correlation of imaging findings and pathological staging of the disease. Finally, a management approach is proposed using combined clinical and radiological findings to determine whether the patient may benefit from surgery or not.

Pearls, Pitfalls, and Conditions that Mimic Mesenteric Ischemia at CT

Acute mesenteric ischemia (AMI) is a life-threatening condition with a high mortality rate. The diagnosis of AMI is challenging because patient symptoms and laboratory test results are often nonspecific. A high degree of clinical and radiologic suspicion is required for accurate and timely diagnosis. CT angiography of the abdomen and pelvis is the first-line imaging test for suspected AMI and should be expedited. A systematic "inside-out" approach to interpreting CT angiographic images, beginning with the bowel lumen and proceeding outward to the bowel wall, mesentery, vasculature, and extraintestinal viscera, provides radiologists with a practical framework to improve detection and synthesis of imaging findings. The subtypes of AMI are arterial and venoocclusive disease, nonocclusive ischemia, and strangulating bowel obstruction; each may demonstrate specific imaging findings. Chronic mesenteric ischemia is more insidious at onset and almost always secondary to atherosclerosis. Potential pitfalls in the diagnosis of AMI include mistaking pneumatosis as a sign that is specific for AMI and not an imaging finding, misinterpretation of adynamic ileus as a benign finding, and pseudopneumatosis. Several enterocolitides can mimic AMI at CT angiography, such as inflammatory bowel disease, infections, angioedema, and radiation-induced enterocolitis. Awareness of pitfalls, conditions that mimic AMI, and potential distinguishing clinical and imaging features can assist radiologists in making an early and accurate diagnosis of AMI. ^©RSNA, 2020.

Evaluation of mesenteric artery disease in patients with severe aortic valve stenosis

The aim of this study is to evaluate the mesenteric artery stenosis (MAS) in routinely performed CT angiography (CTA) of patients with severe aortic stenosis (AS) planned for transcatheter aortic valve implantation (TAVI) before the procedure. Patients with AS (AS group) who routinely underwent CTA before the TAVI procedure due to severe AS and patients who had CTA for other indications (control group) were retrospectively and sequentially scanned. The demographic characteristics of the patients in both groups were similar. Calcification and stenosis in the mesenteric arteries were recorded according to the localization of celiac truncus, superior mesenteric artery (SMA) and inferior mesenteric artery (IMA). Class 0-3 classification was used for calcification score. Stenoses with a stenosis degree ≥50% were considered as significant. A total of 184 patients, 73 patients with severe AS and 111 control groups, were included in the study. SMA and IMA calcification scores of patients with AS were significantly higher than the control group (p=0.035 for SMA and p=0.020 for IMA). In addition, the rate of patients with significant MAS in at least 1 artery (45.2% vs 22.5%, p=0.001) and the rate of patients with significant stenosis in multiple arteries were also significantly higher in the AS group (8.2% vs 1.8%, p=0.037). According to the study results, patients with AS are at a higher risk for MAS. Chronic mesenteric ischemia should be kept in mind in patients with AS who have symptoms such as non-specific abdominal pain and weight loss.

Evaluation and management of the surgical abdomen

PURPOSE OF REVIEW

The aim of this study was to describe important features of clinical examination for the surgical abdomen, relevant investigations, and acute management of common surgical problems in the critically ill.

RECENT FINDINGS

Lactate remains a relatively nonspecific marker of gut ischemia. Dual energy computed tomography (DECT) scan can improve diagnosis of bowel ischemia. Further evidence supports intravenous contrast during CT scan in critically ill patients with acute kidney injury. Outcomes for acute mesenteric ischemia have failed to improve over time; however, increasing use of endovascular approaches, including catheter-directed thrombolysis, may decrease need for laparotomy in the appropriate patient. Nonocclusive mesenteric ischemia remains a challenging diagnostic and management dilemma. Acalculous cholecystitis is managed with a percutaneous cholecystostomy and is unlikely to require interval cholecystectomy. Surgeon comfort with intervention based on point-of-care ultrasound for biliary disease is variable. Mortality for toxic megacolon is decreasing.

SUMMARY

Physical examination remains an integral part of the evaluation of the surgical abdomen. Interpreting laboratory investigations in context and appropriate imaging improves diagnostic ability; intravenous contrast should not be withheld for critically ill patients with acute kidney injury. Surgical intervention should not be delayed for the patient in extremis. The intensivist and surgeon should remain in close communication to optimize care.

Albumin-derived perfluorocarbon-based artificial oxygen carriers can avoid hypoxic tissue damage in massive hemodilution

Artificial blood for clinical use is not yet available therefore, we previously developed artificial oxygen carriers (capsules) and showed their functionality in vitro and biocompatibility in vivo. Herein, we assessed the functionality of the capsules in vivo in a normovolemic hemodilution rat-model. We stepwise exchanged the blood of male Wistar-rats with medium either in the presence of capsules (treatment) or in their absence (control). We investigated tissue hypoxia thoroughly through online biomonitoring, determination of enzyme activity and pancreatic hormones in plasma, histochemical and immunohistochemical staining of small intestine, heart, liver and spleen as well as in situ hybridization of kidneys. After hemodilution, treated animals show higher arterial blood pressure and have a stable body temperature. Additionally, they show a more stable pH, a higher oxygen partial pressure (pO₂), and a lower carbon dioxide partial pressure (pCO₂). Interestingly, blood-glucose-levels drop severely in treated animals, presumably due to glucose consumption. Creatine kinase values in these animals are increased and isoenzyme analysis indicates the spleen as origin. Moreover, the small intestine of treated animals show reduced hypoxic injury compared to controls and the kidneys have reduced expression of the hypoxia-inducible erythropoietin mRNA. In conclusion, our capsules can prevent hypoxic tissue damage. The results provide a proof of concept for capsules as adequate erythrocyte substitute.

Local Intra-arterial Vasodilator Infusion in Non-Occlusive Mesenteric Ischemia Significantly Increases Survival Rate

Purpose

To investigate the outcome of local intra-arterial papaverine infusion therapy in patients with non-occlusive mesenteric ischemia (NOMI), and factors influencing survival, in comparison with a conservative approach.

Methods

From 2013 to 2019, patients with NOMI confirmed by imaging were included in a retrospective two-center study. According to different in-house standard procedures, patients were treated in each center either conservatively or interventionally by a standardized local infusion of intra-arterial papaverine into the splanchnic arteries. Thirty-day mortality and factors influencing the outcome, such as different demographics and laboratories, were compared between groups using Kaplan–Meier survival analysis and Cox regression, respectively.

Results

A total of 66 patients with NOMI were included, with n = 35 treated interventionally (21 males, mean age 67.7 ± 12.3 years) and n = 31 treated conservatively (18 females, mean age 71.6 ± 9.6 years). There was a significant difference in 30-day mortality between the interventional (65.7%; 12/35 survived) and the conservative group (96.8%; 1/31 survived) (hazard ratio 2.44; P = 0.005). Thresholds associated with a worse outcome of interventional therapy are > 7.68 mmol/l for lactate, < 7.31 for pH and <  − 4.55 for base excess.

Conclusion

Local intra-arterial papaverine infusion therapy in patients with NOMI significantly increases survival rate in comparison with conservative treatment. High lactate levels, low pH and high base excess, and high demand for catecholamines are associated with a poor outcome.

Level of Evidence

Level III.

Review Article: Mesenteric Ischemia

PURPOSE OF REVIEW

Mesenteric ischemia (MI), both acute (AMI) and chronic (CMI), is a challenging diagnosis to make, and early diagnosis and treatment are vital to improve outcomes. This manuscript summarizes the most up to date information on diagnosis and treatment of these disorders.

RECENT FINDINGS

There have been several significant advancements in the computed tomography (CT) diagnostic imaging as well as medical and endovascular management of AMI and CMI. In appropriate populations, endovascular interventions appear superior to open surgical management with lower mortality, morbidity, and cost of care. Efficient clinical identification and targeted testing are essential to diagnose AMI and CMI. Aggressive resuscitation and early endovascular (or in select cases, surgical) intervention improve outcomes in those with AMI. In those with CMI, considering this on the differential diagnosis and imaging appropriately can identify those that might benefit from intervention and halt progression to acute episodes.

Impact of Enteral Feeding on Vasoactive Support in Septic Shock: A Retrospective Observational Study

BACKGROUND

Introducing enteral nutrition (EN) during hemodynamic instability may induce the splanchnic steal phenomenon, which may worsen systemic oxygen delivery and increase vasopressor dose. We aimed to determine the change in vasopressor dose in septic shock patients who received concomitant EN. We hypothesize that EN delivery is not associated with worsening hemodynamic instability, as defined by an increase in vasopressor dose ≥50% at 24 hours.

METHODS

This is a retrospective observational cohort study of adult patients with septic shock who were admitted to the intensive care unit from January 2015 to June 2015 and received EN. Vasopressor and EN parameters were collected at 6-hour intervals for the first 24 hours.

RESULTS

Data were available for 28 consecutive patients. The mean age was 60 years (SD = 18), and 54% were females. Norepinephrine (NE) was used in 100%. EN and vasopressor overlap totaled 36 hours (interquartile range [IQR], 27-69). Median NE dose when starting EN was 5.9 μg/min (IQR, 3.88). Median change in dose from 0 to 6 hours was 0.85 μg/min (95% CI, 0.681.06; P = 0.136), corresponding to a median increase of 14.5%. Total NE duration was 60.5 hours (IQR, 47.5-75.5). No serious complications occurred.

CONCLUSION

The median vasopressor dose did not increase by ≥50% during the first 24 hours of EN. This suggests early EN delivered during septic shock is not associated with worsening hemodynamic instability. Limitations include a small sample size and residual confounding. Prospective data are needed.

Prognostic factors of acute mesenteric ischemia in ICU patients

Background

The primary endpoint was to investigate the prognostic factors of acute mesenteric ischemia (AMI) in ICU patients.

Methods

Retrospective observational, non-interventional, monocentric study of a cohort of 214 ICU patients with a confirmed diagnosis of arterial AMI.

Results

We collected demographics, mortality, hospital stay, prior medical history, comorbidities, reasons for ICU admission, laboratory investigations, diagnostic procedures, therapy, severity scores. The 30-day mortality rate was 71% for the 214 patients with arterial AMI. The incidence of nonocclusive mesenteric ischemia was particularly high. AMI was a secondary diagnosis in 58% of patients. Half of the population was represented by surgical patients who mostly required an urgent procedure. The mortality rate was not different in the subgroup with aortic surgery. Three factors were associated with an increase or decrease in mortality: the maximal dose of vasopressors (VP) administered to the patient (OR = 1.20; 95%CI = 1.08–1.33; p <  0.001), arterial change in lactate values within the first 24 h of admission (OR = 1.24; 95%CI = 1.05–1.48; p = 0.012) and anticoagulation (OR = 0.19; 95%CI = 0.043–0.84; p = 0.029).

Conclusions

Fatalities after AMI were related to a high incidence of multi-organ failure. The monitoring of arterial lactate appeared helpful to identify the patients with a poor prognosis.