Incidence, diagnosis, management and outcome of acute mesenteric ischaemia: a prospective, multicentre observational study (AMESI Study).

BACKGROUND: The aim of this multicentre prospective observational study was to identify the incidence, patient characteristics, diagnostic pathway, management and outcome of acute mesenteric ischaemia (AMI). METHODS: All adult patients with clinical suspicion of AMI admitted or transferred to 32 participating hospitals from 06.06.2022 to 05.04.2023 were included. Participants who were subsequently shown not to have AMI or had localized intestinal gangrene due to strangulating bowel obstruction had only baseline and outcome data collected. RESULTS: AMI occurred in 0.038% of adult admissions in participating acute care hospitals worldwide. From a total of 705 included patients, 418 patients had confirmed AMI. In 69% AMI was the primary reason for admission, while in 31% AMI occurred after having been admitted with another diagnosis. Median time from onset of symptoms to hospital admission in patients admitted due to AMI was 24 h (interquartile range 9-48h) and time from admission to diagnosis was 6h (1-12 h). Occlusive arterial AMI was diagnosed in 231 (55.3%), venous in 73 (17.5%), non-occlusive (NOMI) in 55 (13.2%), other type in 11 (2.6%) and the subtype could not be classified in 48 (11.5%) patients. Surgery was the initial management in 242 (58%) patients, of which 59 (24.4%) underwent revascularization. Endovascular revascularization alone was carried out in 54 (13%), conservative treatment in 76 (18%) and palliative care in 46 (11%) patients. From patients with occlusive arterial AMI, revascularization was undertaken in 104 (45%), with 40 (38%) of them in one site admitting selected patients. Overall in-hospital and 90-day mortality of AMI was 49% and 53.3%, respectively, and among subtypes was lowest for venous AMI (13.7% and 16.4%) and highest for NOMI (72.7% and 74.5%). There was a high variability between participating sites for most variables studied. CONCLUSIONS: The overall incidence of AMI and AMI subtypes varies worldwide, and case ascertainment is challenging. Pre-hospital delay in presentation was greater than delays after arriving at hospital. Surgery without revascularization was the most common management approach. Nearly half of the patients with AMI died during their index hospitalization. Together, these findings suggest a need for greater awareness of AMI, and better guidance in diagnosis and management. TRIAL REGISTRATION: NCT05218863 (registered 19.01.2022).

Biomarkers In Prediction of Acute Mesenteric Ischaemia: a prospective multicentre study (BIPAMI study): a study protocol.

BACKGROUND: Acute mesenteric ischaemia (AMI) is a life-threatening disease where early diagnosis is critical to avoid morbidity and mortality from extensive irreversible bowel necrosis. Appropriate prediction of presence of bowel necrosis is currently not available but would help to choose the optimal method of treatment. The study aims to identify combinations of biomarkers that can reliably identify AMI and distinguish between potentially reversible and irreversible bowel ischaemia. METHODS: This is a prospective multicentre study. Adult patients with clinical suspicion of AMI (n = 250) will be included. Blood will be sampled on admission, at and after interventions, or during the first 48 h of suspicion of AMI if no intervention undertaken. Samples will be collected and the following serum or plasma biomarkers measured at Tartu University Hospital laboratory: intestinal fatty acid-binding protein (I-FABP), alpha-glutathione S-transferase (Alpha- GST), interleukin 6 (IL-6), procalcitonin (PCT), ischaemia-modified albumin (IMA), D-lactate, D-dimer, signal peptide-CUB-EGF domain-containing protein 1 (SCUBE-1) and lipopolysaccharide-binding protein (LBP). Additionally, more common laboratory markers will be measured in routine clinical practice at study sites. Diagnosis of AMI will be confirmed by computed tomography angiography, surgery, endoscopy or autopsy. Student's t or Wilcoxon rank tests will be used for comparisons between transmural vs. suspected (but not confirmed) AMI (comparison A), confirmed AMI of any stage vs suspected AMI (comparison B) and non-transmural AMI vs transmural AMI (comparison C). Optimal cut-off values for each comparison will be identified based on the AUROC analysis and likelihood ratios calculated. Positive likelihood ratio > 10 (> 5) and negative likelihood ratio < 0.1 (< 0.2) indicate high (moderate) diagnostic accuracy, respectively. All biomarkers with at least moderate accuracy will be entered as binary covariates (using the best cutoffs) into the multivariable stepwise regression analysis to identify the best combination of biomarkers for all comparisons separately. The best models for each comparison will be used to construct a practical score to distinguish between no AMI, non-transmural AMI and transmural AMI. DISCUSSION: As a result of this study, we aim to propose a score including set of biomarkers that can be used for diagnosis and decision-making in patients with suspected AMI. TRIAL REGISTRATION: NCT06212921 (Registration Date 19-01-2024).

The need for biomarkers to determine response to enteral nutrition during and after critical illness: an update.

PURPOSE OF REVIEW: Biomarkers proposed to provide prognosis or to determine the response to enteral nutrition have been assessed in a number of experimental and clinical studies which are summarized in the current review. RECENT FINDINGS: There are several pathophysiological mechanisms identified which could provide biomarkers to determine response to enteral nutrition. Several biomarkers have been studied, most of them insufficiently and none of them has made its way to clinical practice. Available studies have mainly assessed a simple association of a biomarker with outcomes, but are less focused on dynamic changes in the biomarker levels. Importantly, studies on pathophysiology and clinical features of gastrointestinal dysfunction, including enteral feeding intolerance, are also needed to explore the mechanisms potentially providing specific biomarkers. Not only an association of the biomarker with any adverse outcome, but also a rationale for repeated assessment to assist in treatment decisions during the course of illness is warranted. SUMMARY: There is no biomarker currently available to reliably provide prognosis or determine the response to enteral nutrition in clinical practice, but identification of such a biomarker would be valuable to assist in clinical decision-making.

Gastrointestinal function in critically ill patients.

PURPOSE OF REVIEW: To summarize recent evidence regarding the diagnosis of acute gastrointestinal dysfunction and enteral feeding intolerance, and relationship of these to development of multiple organ dysfunction syndrome, during critical illness. RECENT FINDINGS: Novel gastric feeding tubes that attenuate gastroesophageal regurgitation or facilitate continuous monitoring of gastric motility have been developed. The definition of enteral feeding intolerance remains controversial, which may be resolved using a consensus process. A novel scoring system for gastrointestinal dysfunction (GIDS - GastroIntestinal Dysfunction Score) was recently developed but it is not yet validated or tested to evaluate the effect of any interventions. Studies of biomarkers to identify gastrointestinal dysfunction have yet to yield a suitable biomarker for daily clinical use. SUMMARY: The assessment of gastrointestinal function in critically ill patients continues to rely on complex daily clinical assessment. Scoring systems, consensus definitions and novel technology appear the most promising tools and interventions to improve patient care.

How to avoid harm with feeding critically ill patients: a synthesis of viewpoints of a basic scientist, dietitian and intensivist.

The optimal feeding strategy in critically ill patients is a matter of debate, with current guidelines recommending different strategies regarding energy and protein targets. Several recent trials have added to the debate and question our previous understanding of the provision of nutrition during critical illness. This narrative review aims to provide a summary of interpretation of recent evidence from the view of basic scientist, critical care dietitian and intensivist, resulting in joined suggestions for both clinical practice and future research. In the most recent randomised controlled trial (RCT), patients receiving 6 versus 25 kcal/kg/day by any route achieved readiness for ICU discharge earlier and had fewer GI complications. A second showed that high protein dosage may be harmful in patients with baseline acute kidney injury and more severe illness. Lastly, a prospective observational study using propensity score matched analysis suggested that early full feeding, especially enteral, compared to delayed feeding is associated with a higher 28-day mortality. Viewpoints from all three professionals point to the agreement that early full feeding is likely harmful, whereas important questions regarding the mechanisms of harm as well as on timing and optimal dose of nutrition for individual patients remain unanswered and warrant future studies. For now, we suggest giving low dose of energy and protein during the first few days in the ICU and apply individualised approach based on assumed metabolic state according to the trajectory of illness thereafter. At the same time, we encourage research to develop better tools to monitor metabolism and the nutritional needs for the individual patient accurately and continuously.

Epidemiology of Acute Mesenteric Ischemia: A Population-Based Investigation.

BACKGROUND: There is a lack of population-based studies on acute mesenteric ischemia (AMI). We have therefore performed a nationwide epidemiological study in Estonia, addressing incidence, demographics, interventions and mortality of AMI. METHODS: A retrospective population-based review was conducted of all adult cases of AMI accrued from the digital Estonian Health Insurance Fund and Causes of Death Registry for 2016-2020 based on international classification of diseases (ICD-10) diagnostic codes and procedure codes (NOMESCO). RESULTS: Overall, 577 cases of AMI were identified-an annual incidence of 8.7 per 100,000. The median age was 79 (range 32-104) and 57% were female. Predominating comorbidities included hypertensive disease (81%), atherosclerosis (67%), and atrial fibrillation (52%). The majority of cases (60%) were caused by superior mesenteric artery occlusion (thrombosis 54%, embolism 12%, and unclear 34%). Inferior mesenteric artery occlusion occurred in 7%, non-occlusive mesenteric ischemia in 7%, venous thrombosis in 4%, whereas the type remained unclear in 21% of cases. 40% of patients received intervention (revascularization and/or intestinal resection) and 13% active non-operative treatment. In 21% an exploratory laparotomy or laparoscopy revealed unsalvageable bowel prompting end-of-life care, which was the only management in a further 25% of cases. CONCLUSIONS: The population-based annual incidence of AMI in Estonia was 8.7 per 100,000 during the study period. The overall hospital mortality and 1 year mortality were 64% and 74%, respectively. In the 53% of patients who received active treatment hospital mortality was 32% and 1 year all-cause mortality was 51%. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT04867499.

Intravenous vitamin C therapy in adult patients with sepsis: A rapid practice guideline.

BACKGROUND: This Rapid Practice Guideline provides an evidence-based recommendation to address the question: in adults with sepsis or septic shock, should we recommend using or not using intravenous vitamin C therapy? METHODS: The panel included 21 experts from 16 countries and used a strict policy for potential financial and intellectual conflicts of interest. Methodological support was provided by the Guidelines in Intensive Care, Development, and Evaluation (GUIDE) group. Based on an updated systematic review, and the grading of recommendations, assessment, development, and evaluation approach, we evaluated the certainty of evidence and developed recommendations using the evidence-to-decision framework. We conducted an electronic vote, requiring >80% agreement among the panel for a recommendation to be adopted. RESULTS: At longest follow-up, 90 days, intravenous vitamin C probably does not substantially impact (relative risk 1.05, 95% confidence interval [CI] 0.94 to 1.17; absolute risk difference 1.8%, 95% CI -2.2 to 6.2; 6 trials, n = 2148, moderate certainty). Effects of vitamin C on mortality at earlier timepoints was of low or very low certainty due to risk of bias of the included studies and significant heterogeneity between study results. Few adverse events were reported with the use of vitamin C. The panel did not identify any major differences in other outcomes, including duration of mechanical ventilation, ventilator free days, hospital or intensive care unit length of stay, acute kidney injury, need for renal replacement therapy. Vitamin C may result in a slight reduction in duration of vasopressor support (MD -18.9 h, 95% CI -26.5 to -11.4; 21 trials, n = 2661, low certainty); but may not reduce sequential organ failure assessment scores (MD -0.69, 95% CI -1.55 to 0.71; 24 trials, n = 4002, low certainty). The panel judged the undesirable consequences of using IV vitamin C to probably outweigh the desirable consequences, and therefore issued a conditional recommendation against using IV vitamin C therapy in sepsis. CONCLUSIONS: The panel suggests against use of intravenous vitamin C in adult patients with sepsis, beyond that of standard nutritional supplementation. Small and single center trials on this topic should be discouraged.

Enteral feeding, even when the gut does not feel very good?

PURPOSE OF REVIEW: To summarize knowledge on the gut function in relation to enteral nutrition. RECENT FINDINGS: The gut is certainly suffering during critical illness but our understanding of the exact mechanisms involved is limited. Physicians at bedside are lacking tools to identify how well or bad the gut is doing and whether the gut is responding adequately to critical illness. Sensing nutrition as a signal is important for the gut and microbiome. Enteral nutrition has beneficial effects for the gut perfusion and function. However, early full enteral nutrition in patients with shock was associated with an increased number of rare but serious complications. SUMMARY: Whenever synthesizing knowledge in physiology and available evidence in critically ill, we suggest that enteral nutrition has beneficial effects but may turn harmful if provided too aggressively. Contraindications to enteral nutrition are listed in recent guidelines. For patients with gastrointestinal dysfunction but without these contraindications, we suggest considering early enteral nutrition as a signal to the gut and to the body rather than an energy and protein provision. With this rationale, we think that low dose of enteral nutrition could and probably should be provided also when the gut does not feel very good. Understanding the feedback from the gut in response to enteral nutrition would be important, however, monitoring tools are currently limited to clinical assessment only.

Acute mesenteric ischaemia.

PURPOSE OF REVIEW: To summarize the recent evidence on acute mesenteric ischaemia (AMI). RECENT FINDINGS: The overall incidence of AMI is below 10/100 000 person years but increases exponentially with age. The overall mortality of AMI remains high, exceeding 50%, despite continuing progress and increasing availability of imaging and endovascular interventions. However, patients with (early) revascularization have significantly better outcomes. The majority of patients surviving the acute event are still alive at 1 year, but evidence on quality of life is scarce.Clinical suspicion of AMI is the key to timely diagnosis, with biphasic computed tomography-angiography the diagnostic method of choice. Currently, no biomarker has sufficient specificity to diagnose AMI. SUMMARY: Improved awareness and knowledge of AMI are needed to raise the suspicion of AMI in relevant patients and thereby to achieve better outcomes.

Electrolyte disorders during the initiation of nutrition therapy in the ICU.

PURPOSE OF REVIEW: To summarize recent evidence on prevalence, risk factors, significance, treatment, and prevention of electrolyte disorders in critically ill with a specific focus on disorders during the initiation of nutrition. RECENT FINDINGS: Electrolyte disturbances appear to occur often during critical illness, and most of them seem to be associated with impaired outcome. However, a recent systematic review indicated insufficient evidence to answer clinically relevant questions regarding hypophosphatemia. Similar questions (which thresholds of serum levels are clinically relevant; how serum levels should be corrected and how do different correction regimens/approaches influence outcome) are not clearly answered also for other electrolytes. The most crucial feature of electrolyte disturbances related to feeding is refeeding syndrome. Recent evidence supports that additionally to the correction of electrolyte levels, a temporary restriction of calories (reducing the magnitude of this metabolic feature, including electrolyte shifts) may help to improve outcome. SUMMARY: Diverse electrolyte disorders often occur in critically ill patients. Hypophosphatemia, hypokalemia, and hypomagnesemia that are encountered after initiation of feeding identify refeeding syndrome. Along with correction of electrolytes, reduction of caloric intake may improve the outcome of the refeeding syndrome.

A clinical approach to acute mesenteric ischemia.

PURPOSE OF REVIEW: To summarize current evidence on acute mesenteric ischemia (AMI) in critically ill patients, addressing pathophysiology, definition, diagnosis and management. RECENT FINDINGS: A few recent studies showed that a multidiscipliary approach in specialized centers can improve the outcome of AMI. Such approach incorporates current knowledge in pathophysiology, early diagnosis with triphasic computed tomography (CT)-angiography, immediate endovascular or surgical restoration of mesenteric perfusion, and damage control surgery if transmural bowel infarction is present. No specific biomarkers are available to detect early mucosal injury in clinical setting. Nonocclusive mesenteric ischemia presents particular challenges, as the diagnosis based on CT-findings as well as vascular management is more difficult; some recent evidence suggests a possible role of potentially treatable stenosis of superior mesenteric artery and beneficial effect of vasodilator therapy (intravenous or local intra-arterial). Medical management of AMI is supportive, including aiming of euvolemia and balanced systemic oxygen demand/delivery. Enteral nutrition should be withheld during ongoing ischemia-reperfusion injury and be started at low rate after revascularization of the (remaining) bowel is convincingly achieved. SUMMARY: Clinical suspicion leading to tri-phasic CT-angiography is a mainstay for diagnosis. Diagnosis of nonocclusive mesenteric ischemia and early intestinal injury remains challenging. Multidisciplinary team effort may improve the outcome of AMI.

A guide to enteral nutrition in intensive care units: 10 expert tips for the daily practice.

The preferential use of the oral/enteral route in critically ill patients over gut rest is uniformly recommended and applied. This article provides practical guidance on enteral nutrition in compliance with recent American and European guidelines. Low-dose enteral nutrition can be safely started within 48 h after admission, even during treatment with small or moderate doses of vasopressor agents. A percutaneous access should be used when enteral nutrition is anticipated for ≥ 4 weeks. Energy delivery should not be calculated to match energy expenditure before day 4-7, and the use of energy-dense formulas can be restricted to cases of inability to tolerate full-volume isocaloric enteral nutrition or to patients who require fluid restriction. Low-dose protein (max 0.8 g/kg/day) can be provided during the early phase of critical illness, while a protein target of > 1.2 g/kg/day could be considered during the rehabilitation phase. The occurrence of refeeding syndrome should be assessed by daily measurement of plasma phosphate, and a phosphate drop of 30% should be managed by reduction of enteral feeding rate and high-dose thiamine. Vomiting and increased gastric residual volume may indicate gastric intolerance, while sudden abdominal pain, distension, gastrointestinal paralysis, or rising abdominal pressure may indicate lower gastrointestinal intolerance.

Update on nutritional assessment and therapy in critical care.

PURPOSE OF REVIEW: To summarize recent data regarding nutritional assessment and interventions in the ICU. RECENT FINDINGS: Current methods to assess nutritional risk do not allow identification of ICU patients who may benefit from specific nutritional intervention. Early full energy delivery does not appear to improve outcomes at the population level. Specific nutrient composition of formula has been shown to improve glycemic outcomes in patients with hyperglycemia but patient-centered outcomes are unaffected. SUMMARY: Based on recent studies, full energy feeding early during critical illness has no measurable beneficial effect, and may even be harmful, when applied to entire populations. The mechanisms underlying this are unknown and remain proposed theories. Tools to assess nutritional risk in the ICU that identify patients who will benefit from a specific nutritional intervention are lacking. The optimal composition of feeds, and indications for specific interventions for enteral feeding intolerance remain uncertain.

Gastrointestinal dysfunction in the critically ill: a systematic scoping review and research agenda proposed by the Section of Metabolism, Endocrinology and Nutrition of the European Society of Intensive Care Medicine.

BACKGROUND: Gastrointestinal (GI) dysfunction is frequent in the critically ill but can be overlooked as a result of the lack of standardization of the diagnostic and therapeutic approaches. We aimed to develop a research agenda for GI dysfunction for future research. We systematically reviewed the current knowledge on a broad range of subtopics from a specific viewpoint of GI dysfunction, highlighting the remaining areas of uncertainty and suggesting future studies. METHODS: This systematic scoping review and research agenda was conducted following successive steps: (1) identify clinically important subtopics within the field of GI function which warrant further research; (2) systematically review the literature for each subtopic using PubMed, CENTRAL and Cochrane Database of Systematic Reviews; (3) summarize evidence for each subtopic; (4) identify areas of uncertainty; (5) formulate and refine study proposals that address these subtopics; and (6) prioritize study proposals via sequential voting rounds. RESULTS: Five major themes were identified: (1) monitoring, (2) associations between GI function and outcome, (3) GI function and nutrition, (4) management of GI dysfunction and (5) pathophysiological mechanisms. Searches on 17 subtopics were performed and evidence summarized. Several areas of uncertainty were identified, six of them needing consensus process. Study proposals ranked among the first ten included: prevention and management of diarrhoea; management of upper and lower feeding intolerance, including indications for post-pyloric feeding and opioid antagonists; acute gastrointestinal injury grading as a bedside tool; the role of intra-abdominal hypertension in the development and monitoring of GI dysfunction and in the development of non-occlusive mesenteric ischaemia; and the effect of proton pump inhibitors on the microbiome in critical illness. CONCLUSIONS: Current evidence on GI dysfunction is scarce, partially due to the lack of precise definitions. The use of core sets of monitoring and outcomes are required to improve the consistency of future studies. We propose several areas for consensus process and outline future study projects.

Incidence, Risk Factors, and Outcomes of Intra-Abdominal Hypertension in Critically Ill Patients-A Prospective Multicenter Study (IROI Study).

OBJECTIVES: To identify the prevalence, risk factors, and outcomes of intra-abdominal hypertension in a mixed multicenter ICU population. DESIGN: Prospective observational study. SETTING: Fifteen ICUs worldwide. PATIENTS: Consecutive adult ICU patients with a bladder catheter. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Four hundred ninety-one patients were included. Intra-abdominal pressure was measured a minimum of every 8 hours. Subjects with a mean intra-abdominal pressure equal to or greater than 12 mm Hg were defined as having intra-abdominal hypertension. Intra-abdominal hypertension was present in 34.0% of the patients on the day of ICU admission (159/467) and in 48.9% of the patients (240/491) during the observation period. The severity of intra-abdominal hypertension was as follows: grade I, 47.5%; grade II, 36.6%; grade III, 11.7%; and grade IV, 4.2%. The severity of intra-abdominal hypertension during the first 2 weeks of the ICU stay was identified as an independent predictor of 28- and 90-day mortality, whereas the presence of intra-abdominal hypertension on the day of ICU admission did not predict mortality. Body mass index, Acute Physiology and Chronic Health Evaluation II score greater than or equal to 18, presence of abdominal distension, absence of bowel sounds, and positive end-expiratory pressure greater than or equal to 7 cm H2O were independently associated with the development of intra-abdominal hypertension at any time during the observation period. In subjects without intra-abdominal hypertension on day 1, body mass index combined with daily positive fluid balance and positive end-expiratory pressure greater than or equal to 7 cm H2O (as documented on the day before intra-abdominal hypertension occurred) were associated with the development of intra-abdominal hypertension during the first week in the ICU. CONCLUSIONS: In our mixed ICU patient cohort, intra-abdominal hypertension occurred in almost half of all subjects and was twice as prevalent in mechanically ventilated patients as in spontaneously breathing patients. Presence and severity of intra-abdominal hypertension during the observation period significantly and independently increased 28- and 90-day mortality. Five admission day variables were independently associated with the presence or development of intra-abdominal hypertension. Positive fluid balance was associated with the development of intra-abdominal hypertension after day 1.

Gut dysmotility in the ICU: diagnosis and therapeutic options.

PURPOSE OF REVIEW: To provide a comprehensive update of diagnosis and treatment of gastrointestinal dysmotility in the critically ill, with a focus on work published in the last 5 years. RECENT FINDINGS: Symptoms and clinical features consistent with upper and/or lower gastrointestinal dysmotility occur frequently. Although features of gastrointestinal dysmotility are strongly associated with adverse outcomes, these associations may be because of unmeasured confounders. The use of ultrasonography to identify upper gastrointestinal dysmotility appears promising. Both nonpharmacological and pharmacological approaches to treat gastrointestinal dysmotility have recently been evaluated. These approaches include modification of macronutrient content and administration of promotility drugs, stool softeners or laxatives. Although these approaches may reduce features of gastrointestinal dysmotility, none have translated to patient-centred benefit. SUMMARY: 'Off-label' metoclopramide and/or erythromycin administration are effective for upper gastrointestinal dysmotility but have adverse effects. Trials of alternative or novel promotility drugs have not demonstrated superiority over current pharmacotherapies. Prophylactic laxative regimens to prevent non-defecation have been infrequently studied and there is no recent evidence to further inform treatment of established pseudo-obstruction. Further trials of nonpharmacological and pharmacological therapies to treat upper and lower gastrointestinal dysmotility are required and challenges in designing such trials are explored.

Translating the European Society for Clinical Nutrition and Metabolism 2019 guidelines into practice.

PURPOSE OF REVIEW: To present a pragmatic approach to facilitate clinician's implementing the recent European Society for Clinical Nutrition and Metabolism (ESPEN) guidelines on clinical nutrition in the intensive care unit. RECENT FINDINGS: The ESPEN guidelines include 54 recommendations with a rationale for each recommendation. All data published since 1 January 2000 was reviewed and 31 meta-analyses were performed to inform these guidelines. An important aspect of the most recent ESPEN guidelines is an attempt to separate periods of critical illness into discrete - early acute, late acute and recovery - phases, with each exhibiting different metabolic profiles and requiring different strategies for nutritional and metabolic support. SUMMARY: A pragmatic approach to incorporate the recent ESPEN guidelines into everyday clinical practice is provided.

Gastrointestinal failure in the ICU.

PURPOSE OF REVIEW: The current review summarizes different aspects of assessment of gastrointestinal function and provides a practical approach to management of adult patients with gastrointestinal dysfunction in the ICU. RECENT FINDINGS: Different ways to define gastrointestinal failure have been used in the past. Recently, the term 'acute gastrointestinal injury (AGI)' has been proposed to specifically describe gastrointestinal dysfunction as a part of multiple organ dysfunction syndrome. Possible pathophysiological mechanisms and different aspects in assessment of gastrointestinal function in adult ICU patients are presented. Currently, there is no single marker that could reliably describe gastrointestinal dysfunction. Therefore, monitoring and management is still based on complex assessment of different gastrointestinal symptoms and feeding intolerance, even though this approach includes a large amount of subjectivity. The possible role of biomarkers (citrulline, enterohormones, etc.) and additional parameters like intra-abdominal pressure remains to be clarified. SUMMARY: Defining gastrointestinal failure remains challenging but broad consensus needs to be reached and disseminated soon to allow conduct of interventional studies. A systematic approach to management of gastrointestinal problems is recommended.