Update of the European Society of Anaesthesiology and Intensive Care Medicine evidence-based and consensus-based guideline on postoperative delirium in adult patients

Postoperative delirium (POD) remains a common, dangerous and resource-consuming adverse event but is often preventable. The whole peri-operative team can play a key role in its management. This update to the 2017 ESAIC Guideline on the prevention of POD is evidence-based and consensus-based and considers the literature between 01 April 2015, and 28 February 2022. The search terms of the broad literature search were identical to those used in the first version of the guideline published in 2017. POD was defined in accordance with the DSM-5 criteria. POD had to be measured with a validated POD screening tool, at least once per day for at least 3 days starting in the recovery room or postanaesthesia care unit on the day of surgery or, at latest, on postoperative day 1. Recent literature confirmed the pathogenic role of surgery-induced inflammation, and this concept reinforces the positive role of multicomponent strategies aimed to reduce the surgical stress response. Although some putative precipitating risk factors are not modifiable (length of surgery, surgical site), others (such as depth of anaesthesia, appropriate analgesia and haemodynamic stability) are under the control of the anaesthesiologists. Multicomponent preoperative, intra-operative and postoperative preventive measures showed potential to reduce the incidence and duration of POD, confirming the pivotal role of a comprehensive and team-based approach to improve patients' clinical and functional status.

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).

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

ESPEN practical and partially revised guideline: Clinical nutrition in the intensive care unit

Following the new ESPEN Standard Operating Procedures, the previous 2019 guideline to provide best medical nutritional therapy to critically ill patients has been shortened and partially revised. Following this update, we propose this publication as a practical guideline based on the published scientific guideline, but shortened and illustrated by flow charts. The main goal of this practical guideline is to increase understanding and allow the practitioner to implement the Nutrition in the ICU guidelines. All the items discussed in the previous guidelines are included as well as special conditions.

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.

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.

Management of acute mesenteric ischaemia: Results of a worldwide survey

BACKGROUND

Acute mesenteric ischaemia (AMI) is a condition with high mortality. This survey assesses current attitudes and practices to manage AMI worldwide.

METHODS

A questionnaire survey about the practices of diagnosing and managing AMI, endorsed by several specialist societies, was sent to different medical specialists and hospitals worldwide. Data from individual health care professionals and from medical teams were collected.

RESULTS

We collected 493 individual forms from 71 countries and 94 team forms from 34 countries. Almost half of respondents were surgeons, and most of the responding teams (70%) were led by surgeons. Most of the respondents indicated that diagnosis of AMI is often delayed but rarely missed. Emergency revascularisation is often considered for patients with AMI but rarely in cases of transmural ischaemia (intestinal infarction). Responses from team hospitals with a dedicated special unit (14 team forms) indicated more aggressive revascularisation. Abdominopelvic CT-scan with intravenous contrast was suggested as the most useful diagnostic test, indicated by approximately 90% of respondents. Medical history and risk factors were thought to be more important in diagnosis of AMI without transmural ischaemia, whereas for intestinal infarction, plasma lactate concentrations and surgical exploration were considered more useful. In elderly patients, a palliative approach is often chosen over extensive bowel resection. There was a large variability in anticoagulant treatment, as well as in timing of surgery to restore bowel continuity.

CONCLUSIONS

Delayed diagnosis of AMI is common despite wide availability of an adequate imaging modality, i.e. CT-scan. Large variability in treatment approaches exists, indicating the need for updated guidelines. Increased awareness and knowledge of AMI may improve current practice until more robust evidence becomes available. Adherence to the existing guidelines may help in improving differences in treatment and outcomes.

Current practice of gastric residual volume measurements and related outcomes of critically ill patients - a secondary analysis of the iSOFA study

BACKGROUND

Gastric residual volumes (GRV) measurement to detect gastrointestinal (GI) dysfunction is one of the most common diagnostic procedures in critical care, albeit still not well standardized being operator-, patient-, and tube-dependent. Our aim was to describe current practice of GRV measurements and its association with clinical outcomes in a mixed cohort of adult critically ill patients.

METHODS

This was a secondary analysis of an international prospective observational cohort study (iSOFA). Eligibility criteria were defined as ≥ 1 GRV measurement during the 7-day study period. Data collection included GRV measurement practices, tube diameters and volumes, symptoms of GI dysfunction, and clinical outcomes. The primary aim was to describe current practices of GRV measurements, secondary aim was to test the association of high (> 200 ml) vs. low GRV with symptoms of GI dysfunction and clinical outcomes using generalized linear regression and survival models.

RESULTS

258 patients with 2422 GRV measurements on 875 study days were analyzed. GRV was mainly measured via passive drainage twice daily using large diameter tubes. There was no significant association between tube size or measurement technique and high GRV. High GRV occurred in 34% of patients and was associated with other GI symptoms and with increased disease severity, but not with 28-day, 90-day mortality, ICU free or ventilator free days.

CONCLUSION

There was substantial variability of GRV measurement techniques, but this had no impact on the amount of GRV. High GRV was not associated with mortality or ventilator free days, but may serve as a marker of GI dysfunction and disease severity. This article is protected by copyright. All rights reserved.

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.

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.

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

OBJECTIVE

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

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

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

ELIGIBILITY CRITERIA

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

DATA EXTRACTION AND SYNTHESIS

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

RESULTS

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

CONCLUSIONS

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

PROSPERO REGISTRATION NUMBER

CRD42021247148.

Impact of intraabdominal hypertension on kidney failure in critically ill patients: A post-hoc database analysis

PURPOSE

To assess whether intraabdominal hypertension (IAH) may influence kidney failure as well as mortality.

METHODS

This post-hoc analysis of two databases (IROI and iSOFA study) tested the independent association between IAH and kidney failure. Mortality was assessed using four prespecified groups (IAH present, kidney failure present, IAH and kidney failure present and no IAH or kidney failure present).

RESULTS

Of 825 critically ill patients, 302 (36.6%) developed kidney failure and 192 (23.7%) died during the first 90 days. Only 'Cumulative days with IAH grade II or more' was significantly associated with kidney failure (OR 1.29 (1.08-1.55), p = 0.003) while 'cumulative days with IAH grade I or more' (p = 0.135) or highest daily IAP (p = 0.062) was not. IAH combined with kidney failure was independently associated with 90-day mortality (OR 2.20 (1.20-4.05), p = 0.011), which was confirmed for higher grades of IAH (grade II or more) alone (OR 2.14 (1.07-4.30), p = 0.032) and combined with kidney failure (OR 3.25 (1.72-6.12), p < 0.001).

CONCLUSIONS

This study suggest that duration as well as higher grades of IAH are associated with kidney failure and may increase mortality.

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.

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.

Enteral nutrition and dynamics of citrulline and intestinal fatty acid-binding protein in adult ICU patients

BACKGROUND AND AIMS

Plasma citrulline and intestinal fatty acid binding protein (I-FABP) are biomarkers reflecting enterocyte function and intestinal mucosal injury. The aim was to describe daily dynamics of citrulline and I-FABP concentrations in association with enteral nutrition (EN) in adult ICU patients. We hypothesized that success or failure of EN is reflected by differences in citrulline and I-FABP levels at admission, as well as in daily dynamics over the first week.

METHODS

The present study was a planned sub-study of the iSOFA study (ClinicalTrials.gov Identifier: NCT02613000). With delayed informed consent we included adult (18 years or older) patients admitted for unlimited care to 5 ICUs in Europe. Citrulline and I-FABP were assessed and nutritional data recorded daily during the first week of the patients' ICU stay.

RESULTS

The study included 224 patients with 693 plasma samples analyzed for citrulline and 695 for I-FABP. The median ICU stay was 2 (IQR 1-4) days and 35 patients (15.6 %) stayed in the ICU for ≥ 7 days. The majority of patients (184/224; 82.1 %) received EN or oral nutrition (ON) during their ICU stay, in 164 patients (73.2 %) nutrition was started within 48 h of admission (early enteral or oral nutrition, EEN/ON). Median biomarker concentrations on admission were: citrulline 24.5 (IQR 18.1-31.7) μmol/L and I-FABP 2763 (1326-4805) pg/mL. Reference range for citrulline was 17-46 μmol/L and for I-FABP 377-2049 pg/mL. Patients with EEN/ON demonstrated an increase in citrulline concentrations over the first week in ICU unlike those not receiving EEN/ON (P = 0.049 for the mean log-citrulline values over time between groups) as well as higher average citrulline concentrations. Success of EEN/ON (80 % of caloric target achieved by day 4) was associated with citrulline values increasing from day 4, whereas a slight decrease was observed with unsuccessful EEN/ON. However, these dynamics over time were not statistically significantly different (P = 0.654). Patients with EEN/ON unexpectedly had I-FABP values higher than those without (average values for all days P = 0.004). Median I-FABP values on day 3 were higher with successful EEN/ON (646 (IQR 313-1116) vs 278 (IQR 190-701) pg/mL, P = 0.022).

CONCLUSIONS

EEN/ON was associated with higher values and different dynamics of citrulline over the first week in ICU. No clear difference of measured biomarkers was seen when patients were compared according to success of EEN/ON. Our study does not allow suggesting certain thresholds of citrulline nor I-FABP that could be used for bedside decision-making with regard to EN. This study was a planned sub-study of the iSOFA study (ClinicalTrials.gov Identifier: NCT02613000).

Development of the Gastrointestinal Dysfunction Score (GIDS) for critically ill patients - A prospective multicenter observational study (iSOFA study)

BACKGROUND & AIMS

To develop a five grade score (0-4 points) for the assessment of gastrointestinal (GI) dysfunction in adult critically ill patients.

METHODS

This prospective multicenter observational study enrolled consecutive adult patients admitted to 11 intensive care units in nine countries. At all sites, daily clinical data with emphasis on GI clinical symptoms were collected and intra-abdominal pressure measured. In five out of 11 sites, the biomarkers citrulline and intestinal fatty acid-binding protein (I-FABP) were measured additionally. Cox models with time-dependent scores were used to analyze associations with 28- and 90-day mortality. The models were estimated with stratification for study center.

RESULTS

We included 540 patients (224 with biomarker measurements) with median age of 65 years (range 18-94), the Simplified Acute Physiology Score II score of 38 (interquartile range 26-53) points, and Sequential Organ Failure Assessment (SOFA) score of 6 (interquartile range 3-9) points at admission. Median ICU length of stay was 3 (interquartile range 1-6) days and 90-day mortality 18.9%. A new five grade Gastrointestinal Dysfunction Score (GIDS) was developed based on the rationale of the previously developed Acute GI Injury (AGI) grading. Citrulline and I-FABP did not prove their potential for scoring of GI dysfunction in critically ill. GIDS was independently associated with 28- and 90-day mortality when added to SOFA total score (HR 1.40; 95%CI 1.07-1.84 and HR 1.40; 95%CI 1.02-1.79, respectively) or to a model containing all SOFA subscores (HR 1.48; 95%CI 1.13-1.92 and HR 1.47; 95%CI 1.15-1.87, respectively), improving predictive power of SOFA score in all analyses.

CONCLUSIONS

The newly developed GIDS is additive to SOFA score in prediction of 28- and 90-day mortality. The clinical usefulness of this score should be validated prospectively.

TRIAL REGISTRATION

NCT02613000, retrospectively registered 24 November 2015.

Deepening of sedation with propofol has limited effect on intra-abdominal pressure - An interventional study in mechanically ventilated adult patients with intra-abdominal hypertension

PURPOSE

To evaluate the effect of deepening of sedation on intra-abdominal pressure (IAP).

METHODS

37 adult mechanically ventilated ICU patients with intra-abdominal hypertension received a bolus dose and subsequent infusion of propofol (bolus: 1 mg/kg, infusion: 3 mg/kg/h). IAP, mean arterial pressure (MAP), abdominal perfusion pressure (APP), depth of sedation according to Richmond Agitation-Sedation Scale (RASS), respiratory parameters, and vasopressor dose were assessed after bolus and at 15, 30 and 60 min of infusion of propofol.

RESULTS

Median IAP at baseline was 15 (13-16) mm Hg. During the intervention, median IAP decreased by 1 mm Hg at all time points. In 24% of patients IAP decreased by ≥3 mm Hg. Compared to baseline, MAP and APP were reduced at all time points. Deepening of sedation per RASS was achieved in 70% of patients at all time points. No changes in respiratory tidal volumes nor plateau pressures were observed. Vasopressor therapy with noradrenaline was started or increased in 43% of patients, whereas the increase in patients already receiving noradrenaline prior to the intervention was not significant.

CONCLUSIONS

Deepening of sedation with propofol results in a small decrease in IAP and greater simultaneous decrease in MAP and APP, requiring increased vasopressor support in some cases.

Intra-abdominal hypertension and hypoxic respiratory failure together predict adverse outcome - A sub-analysis of a prospective cohort

PURPOSE

To assess whether the combination of intra-abdominal hypertension (IAH, intra-abdominal pressure ≥ 12 mmHg) and hypoxic respiratory failure (HRF, PaO2/FiO2 ratio < 300 mmHg) in patients receiving invasive ventilation is an independent risk factor for 90- and 28-day mortality as well as ICU- and ventilation-free days.

METHODS

Mechanically ventilated patients who had blood gas analyses performed and intra-abdominal pressure measured, were included from a prospective cohort. Subgroups were defined by the absence (Group 1) or the presence of either IAH (Group 2) or HRF (Group 3) or both (Group 4). Mixed-effects regression analysis was performed.

RESULTS

Ninety-day mortality increased from 16% (Group 1, n = 50) to 30% (Group 2, n = 20) and 27% (Group 3, n = 100) to 49% (Group 4, n = 142), log-rank test p < 0.001. The combination of IAH and HRF was associated with increased 90- and 28-day mortality as well as with fewer ICU- and ventilation-free days. The association with 90-day mortality was no longer present after adjustment for independent variables. However, the association with 28-day mortality, ICU- and ventilation-free days persisted after adjusting for independent variables.

CONCLUSIONS

In our sub-analysis, the combination of IAH and HRF was not independently associated with 90-day mortality but independently increased the odds of 28-day mortality, and reduced the number of ICU- and ventilation-free days.

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.

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.

Are Classic Bedside Exam Findings Required to Initiate Enteral Nutrition in Critically Ill Patients: Emphasis on Bowel Sounds and Abdominal Distension

The general physical examination of a patient is an axiom of critical care medicine, but evidence to support this practice remains sparse. Given the lack of evidence for a comprehensive physical examination of the entire patient on admission to the intensive care unit, which most clinicians consider an essential part of care, should clinicians continue the practice of a specialized gastrointestinal system physical examination when commencing enteral nutrition in critically ill patients? In this review of literature related to gastrointestinal system examination in critically ill patients, the focus is on gastrointestinal sounds and abdominal distension. There is a summary of what these physical features represent, an evaluation of the evidence regarding use of these physical features in patients after abdominal surgery, exploration of the rationale for and against using the physical findings in routine practice, and detail regarding what is known about each feature in critically ill patients. Based on the available evidence, it is recommended that an isolated symptom, sign, or bedside test does not provide meaningful information. However, it is submitted that a comprehensive physical assessment of the gastrointestinal system still has a role when initiating or administering enteral nutrition: specifically, when multiple features are present, clinicians should consider further investigation or intervention.

Hypophosphatemia in critically ill adults and children - A systematic review

BACKGROUND & AIMS

Phosphate is the main intracellular anion essential for numerous biological processes. Symptoms of hypophosphatemia are non-specific, yet potentially life-threatening. This systematic review process was initiated to gain a global insight into hypophosphatemia, associated morbidity and treatments.

METHODS

A systematic review was conducted (PROSPERO CRD42020163191). Nine clinically relevant questions were generated, seven for adult and two for pediatric critically ill patients, and prevalence of hypophosphatemia was assessed in both groups. We identified trials through systematic searches of Medline, EMBASE, Scopus, Cochrane Central Register of Controlled Trials, CINAHL, and Web of Science. Quality assessment was performed using the Cochrane risk of bias tool for randomized controlled trials and the Newcastle-Ottawa Scale for observational studies.

RESULTS

For all research questions, we identified 2727 titles in total, assessed 399 full texts, and retained 82 full texts for evidence synthesis, with 20 of them identified for several research questions. Only 3 randomized controlled trials were identified with two of them published only in abstract form, as well as 28 prospective and 31 retrospective studies, and 20 case reports. Relevant risk of bias regarding selection and comparability was identified for most of the studies. No meta-analysis could be performed. The prevalence of hypophosphatemia varied substantially in critically ill adults and children, but no study assessed consecutive admissions to intensive care. In both critically ill adults and children, several studies report that hypophosphatemia is associated with worse outcome (prolonged length of stay and the need for respiratory support, and higher mortality). However, there was insufficient evidence regarding the optimal threshold upon which hypophosphatemia becomes critical and requires treatment. We found no studies regarding the optimal frequency of phosphate measurements, and regarding the time window to correct hypophosphatemia. In adults, nutrient restriction on top of phosphate repletion in patients with refeeding syndrome may improve survival, although evidence is weak.

CONCLUSIONS

Evidence on the definition, outcome and treatment of clinically relevant hypophosphatemia in critically ill adults and children is scarce and does not allow answering clinically relevant questions. High quality clinical research is crucial for the development of respective guidelines.

Efficacy and safety of gastrointestinal bleeding prophylaxis in critically ill patients: an updated systematic review and network meta-analysis of randomized trials

PURPOSE

Motivated by a new randomized trial (the PEPTIC trial) that raised the issue of an increase in mortality with proton pump inhibitors (PPIs) relative to histamine-2 receptor antagonists (H2RAs), we updated our prior systematic review and network meta-analysis (NMA) addressing the impact of pharmacological gastrointestinal bleeding prophylaxis in critically ill patients.

METHODS

We searched for randomized controlled trials that examined the efficacy and safety of gastrointestinal bleeding prophylaxis with PPIs, H2RAs, or sucralfate versus one another or placebo or no prophylaxis in adult critically ill patients. We performed Bayesian random-effects NMA and conducted analyses using all PEPTIC data as well as a restricted analysis using only PEPTIC data from high compliance centers. We used the GRADE approach to quantify absolute effects and assess the certainty of evidence.

RESULTS

Seventy-four trials enrolling 39 569 patients proved eligible. Both PPIs (risk ratio (RR) 1.03, 95% credible interval 0.93 to 1.14, moderate certainty) and H2RAs (RR 0.98, 0.89 to 1.08, moderate certainty) probably have little or no impact on mortality compared with no prophylaxis. There may be no important difference between PPIs and H2RAs on mortality (RR 1.05, 0.97 to 1.14, low certainty), the 95% credible interval of the complete analysis has not excluded an important increase in mortality with PPIs. Both PPIs (RR 0.46, 0.29 to 0.66) and H2RAs (RR 0.67, 0.48 to 0.94) probably reduce clinically important gastrointestinal bleeding; the magnitude of reduction is probably greater in PPIs than H2RAs (RR 0.69, 0.45 to 0.93), and the difference may be important in higher, but not lower bleeding risk patients. PPIs (RR 1.08, 0.88 to 1.45, low certainty) and H2RAs (RR 1.07, 0.85 to 1.37, low certainty) may have no important impact on pneumonia compared with no prophylaxis.

CONCLUSION

This updated NMA confirmed that PPIs and H2RAs are most likely to have a similar effect on mortality compared to each other and compared to no prophylaxis; however, the possibility that PPIs may slightly increase mortality cannot be excluded (low certainty evidence). PPIs and H2RAs probably achieve important reductions in clinically important gastrointestinal bleeding; for higher bleeding risk patients, the greater benefit of PPIs over H2RAs may be important. PPIs or H2RAs may not result in important increases in pneumonia but the certainty of evidence is low.

Monitoring and parenteral administration of micronutrients, phosphate and magnesium in critically ill patients: The VITA-TRACE survey

BACKGROUND & AIMS

Despite the presumed importance of preventing and treating micronutrient and mineral deficiencies, it is still not clear how to optimize measurement and administration in critically ill patients. In order to design future comparative trials aimed at optimizing micronutrient and mineral management, an important first step is to gain insight in the current practice of micronutrient, phosphate and magnesium monitoring and administration.

METHODS

Within the metabolism-endocrinology-nutrition (MEN) section of the European Society of Intensive Care Medicine (ESICM), the micronutrient working group designed a survey addressing current practice in parenteral micronutrient and mineral administration and monitoring. Invitations were sent by the ESICM research department to all ESICM members and past members.

RESULTS

Three hundred thirty-four respondents completed the survey, predominantly consisting of physicians (321 [96.1%]) and participants working in Europe (262 [78.4%]). Eighty-one (24.3%) respondents reported to monitor micronutrient deficiencies through clinical signs and/or laboratory abnormalities, and 148 (44.3%) reportedly measure blood micronutrient concentrations on a routine basis. Two hundred ninety-two (87.4%) participants provided specific data on parenteral micronutrient supplementation, of whom 150 (51.4%) reported early administration of combined multivitamin and trace element preparations at least in selected patients. Among specific parenteral micronutrient preparations, thiamine (146 [50.0%]) was reported to be the most frequently administered micronutrient, followed by vitamin B complex (104 [35.6%]) and folic acid (86 [29.5%]). One hundred twenty (35.9%) and 113 (33.8%) participants reported to perform daily measurements of phosphate and magnesium, respectively, whereas 173 (59.2%) and 185 (63.4%) reported to routinely supplement these minerals parenterally.

CONCLUSION

The survey revealed a wide variation in current practices of micronutrient, phosphate and magnesium measurement and parenteral administration, suggesting a risk of insufficient prevention, diagnosis and treatment of deficiencies. These results provide the context for future comparative studies, and identify areas for knowledge translation and recommendations.

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.

Gastrointestinal bleeding prophylaxis for critically ill patients: a clinical practice guideline

CLINICAL QUESTION

What is the role of gastrointestinal bleeding prophylaxis (stress ulcer prophylaxis) in critically ill patients? This guideline was prompted by the publication of a new large randomised controlled trial.

CURRENT PRACTICE

Gastric acid suppression with proton pump inhibitors (PPIs) or histamine-2 receptor antagonists (H2RAs) is commonly done to prevent gastrointestinal bleeding in critically ill patients. Existing guidelines vary in their recommendations of which population to treat and which agent to use.

RECOMMENDATIONS

This guideline panel makes a weak recommendation for using gastrointestinal bleeding prophylaxis in critically ill patients at high risk (>4%) of clinically important gastrointestinal bleeding, and a weak recommendation for not using prophylaxis in patients at lower risk of clinically important bleeding (≤4%). The panel identified risk categories based on evidence, with variable certainty regarding risk factors. The panel suggests using a PPI rather than a H2RA (weak recommendation) and recommends against using sucralfate (strong recommendation).

HOW THIS GUIDELINE WAS CREATED

A guideline panel including patients, clinicians, and methodologists produced these recommendations using standards for trustworthy guidelines and the GRADE approach. The recommendations are based on a linked systematic review and network meta-analysis. A weak recommendation means that both options are reasonable.

THE EVIDENCE

The linked systematic review and network meta-analysis estimated the benefit and harm of these medications in 12 660 critically ill patients in 72 trials. Both PPIs and H2RAs reduce the risk of clinically important bleeding. The effect is larger in patients at higher bleeding risk (those with a coagulopathy, chronic liver disease, or receiving mechanical ventilation but not enteral nutrition or two or more of mechanical ventilation with enteral nutrition, acute kidney injury, sepsis, and shock) (moderate certainty). PPIs and H2RAs might increase the risk of pneumonia (low certainty). They probably do not have an effect on mortality (moderate certainty), length of hospital stay, or any other important outcomes. PPIs probably reduce the risk of bleeding more than H2RAs (moderate certainty).

UNDERSTANDING THE RECOMMENDATION

In most critically ill patients, the reduction in clinically important gastrointestinal bleeding from gastric acid suppressants is closely balanced with the possibility of pneumonia. Clinicians should consider individual patient values, risk of bleeding, and other factors such as medication availability when deciding whether to use gastrointestinal bleeding prophylaxis. Visual overviews provide the relative and absolute benefits and harms of the options in multilayered evidence summaries and decision aids available on MAGICapp.

Abdominal Compartment Syndrome: Improving Outcomes With A Multidisciplinary Approach - A Narrative Review

Abdominal compartment syndrome (ACS) refers to a severe increase in intra-abdominal pressure associated with single or multiorgan failure. ACS with specific pathophysiological processes and detrimental outcomes may occur in a variety of clinical conditions. Patients with ACS are predominantly managed in critical care settings, however, a wide range of multidisciplinary interventions are frequently required from medical, surgical, radiological and nursing specialties. The medical management, aiming to prevent the progression of intra-abdominal hypertension to ACS, is extensively reviewed. Timing and techniques of surgical decompression techniques, as well as management of open abdomen, are outlined. In summary, the current narrative review provides data on history, definitions, epidemiology and pathophysiology of the syndrome and highlights the importance of multidisciplinary approach in the management of ACS in adults.

Gastrointestinal failure affects outcome of intensive care

PURPOSE

Goal of this study was to describe incidence and outcome of gastrointestinal failure (GIF) in ICU patients, evaluate its additive role to SOFA score in mortality prediction and describe GIF according to etiology.

MATERIALS AND METHODS

A retrospective study with prospective data collection was conducted in mixed adult ICU patients admitted 2004-2015. GIF was considered present if ≥3 of following 6 symptoms occurred in 1 day: maximum gastric residual volume ≥ 500 mL; absent bowel sounds; vomiting or regurgitation; diarrhea; suspected or radiologically confirmed bowel distension; gastrointestinal bleeding. Division into primary (gastrointestinal pathology causing GIF) and secondary (due to other conditions) GIF was made based on origin of syndrome.

RESULTS

GIF developed in 413 (10.4%) of 3959 patients. Primary GIF occurred in 61.3% and secondary GIF in 38.7% of patients. Development of GIF was associated with longer mechanical ventilation, ICU stay and higher ICU, 30-day and 90-day mortality. Outcomes of patients with primary and secondary GIF were similar. All SOFA sub-scores and number of gastrointestinal symptoms on admission day independently predicted 90-day mortality.

CONCLUSIONS

Gastrointestinal failure, independent of origin, is associated with worse ICU outcome. Similar to other organ failures included in SOFA score, GIF independently predicts mortality.

Acute intestinal failure: International multicenter point-of-prevalence study

BACKGROUND & AIMS

Intestinal failure (IF) is defined from a requirement or intravenous supplementation due to failing capacity to absorb nutrients and fluids. Acute IF is an acute, potentially reversible form of IF. We aimed to identify the prevalence, underlying causes and outcomes of acute IF.

METHODS

This point-of-prevalence study included all adult patients hospitalized in acute care hospitals and receiving parenteral nutrition (PN) on a study day. The reason for PN and the mechanism of IF (if present) were documented by local investigators and reviewed by an expert panel.

RESULTS

Twenty-three hospitals (19 university, 4 regional) with a total capacity of 16,356 acute care beds and 1237 intensive care unit (ICU) beds participated in this study. On the study day, 338 patients received PN (21 patients/1000 acute care beds) and 206 (13/1000) were categorized as acute IF. The categorization of reason for PN was revised in 64 cases (18.9% of total) in consensus between the expert panel and investigators. Hospital mortality of all study patients was 21.5%; the median hospital stay was 36 days. Patients with acute IF had a hospital mortality of 20.5% and median hospital stay of 38 days (P > 0.05 for both outcomes). Disordered gut motility (e.g. ileus) was the most common mechanism of acute IF, and 71.5% of patients with acute IF had undergone abdominal surgery. Duration of PN of ≥42 days was identified as being the best cut-off predicting hospital mortality within 90 days. PN ≥ 42 days, age, sepsis and ICU admission were independently associated with 90-day hospital mortality.

CONCLUSIONS

Around 2% of adult patients in acute care hospitals received PN, 60% of them due to acute IF. High 90-day hospital mortality and long hospital stay were observed in patients receiving PN, whereas presence of acute IF did not additionally influence these outcomes. Duration of PN was associated with increased 90-day hospital mortality.

Intestinal failure in adults: Recommendations from the ESPEN expert groups

BACKGROUND & AIMS

Intestinal failure (IF) is defined as "the reduction of gut function below the minimum necessary for the absorption of macronutrients and/or water and electrolytes, such that intravenous supplementation is required to maintain health and/or growth". Functionally, it may be classified as type I acute intestinal failure (AIF), type II prolonged AIF and type III chronic intestinal failure (CIF) The ESPEN Workshop on IF was held in Bologna, Italy, on 15-16 October 2017 and the aims of this document were to highlight the current state of the art and future directions for research in IF.

METHODS

This paper represents the opinion of experts in the field, based on current evidence. It is not a formal review, but encompasses the current evidence, with emphasis on epidemiology, classification, diagnosis and management.

RESULTS

IF is the rarest form of organ failure and can result from a variety of conditions that affect gastrointestinal anatomy and function adversely. Assessment, diagnosis, and short and long-term management involves a multidisciplinary team with diverse expertise in the field that aims to reduce complications, increase life expectancy and improve quality of life in patients.

CONCLUSIONS

Both AIF and CIF are relatively rare conditions and most of the published work presents evidence from small, single-centre studies. Much remains to be investigated to improve the diagnosis and management of IF and future studies should rely on multidisciplinary, multicentre and multinational collaborations that gather data from large cohorts of patients. Emphasis should also be placed on partnership with patients, carers and government agencies in order to improve the quality of research that focuses on patient-centred outcomes that will help to improve both outcomes and quality of life in patients with this devastating condition.

Pathophysiology and Treatment of Gastrointestinal Motility Disorders in the Acutely Ill

Gastrointestinal dysmotility causes delayed gastric emptying, enteral feed intolerance, and functional obstruction of the small and large intestine, the latter functional obstructions being frequently termed ileus and Ogilvie syndrome, respectively. In addition to meticulous supportive care, drug therapy may be appropriate in certain situations. There is, however, considerable variation among individuals regarding what gastric residual volume identifies gastric dysmotility and would encourage use of a promotility drug. While the administration of either metoclopramide or erythromycin is supported by evidence it appears that, dual-drug therapy (erythromycin and metoclopramide) reduces the rate of treatment failure. There is a lack of evidence to guide drug therapy of ileus, but neither erythromycin nor metoclopramide appear to have a role. Several drugs, including ghrelin agonists, highly selective 5-hydroxytryptamine receptor agonists, and opiate antagonists are being studied in clinical trials. Neostigmine, when infused at a relatively slow rate in patients receiving continuous hemodynamic monitoring, may alleviate the need for endoscopic decompression in some patients.

Early or Late Feeding after ICU Admission?

The feeding of critically ill patients has recently become a controversial issue, as several studies have provided unexpected and contradictory results. Earlier beliefs regarding energy requirements in critical illness—especially during the initial phase—have been challenged. In the current review, we summarize existing evidence about fasting and the impact of early vs. late feeding on the sick organism’s responses. The most important points are the non-nutritional advantages of using the intestine, and recognition that early endogenous energy production as an important player in the response must be integrated in the nutrient prescription. There is as of yet no bedside tool to monitor dynamics in metabolism and the magnitude of the endogenous energy production. Hence, an early “full-feeding strategy” exposes patients to involuntary overfeeding, due to the absence of an objective measure enabling the adjustment of the nutritional therapy. Suggestions for future research and clinical practice are proposed.

Perioperative gastrointestinal problems in the ICU

Gastrointestinal (GI) problems after surgery are common and are not limited to patients undergoing abdominal surgery. GI function is complicated to monitor and is not included in organ dysfunction scores widely used in the ICUs. In most cases, it recovers after surgery, if systemic and local inflammation and perfusion improve, gut oedema resolves, and analgosedation is reduced. However, perioperative GI problems may have severe consequences and increase the risk of death if not recognized and managed in a timely manner. Careful risk evaluation followed by a complex structured assessment and appropriate management of GI symptoms should minimize the potentially severe consequences and thereby possibly improve outcome. In the current review, we summarize common non-specific perioperative GI problems and some specific surgery-related abdominal problems, address identification of patients at risk of GI problems, and give suggestions for perioperative GI management.

The black box revelation: monitoring gastrointestinal function

The gastrointestinal tract comprises diverse functions. Despite recent developments in technology and science, there is no single and universal tool to monitor GI function in intensive care unit (ICU) patients. Clinical evaluation is complex and has a low sensitivity to diagnose pathological processes in the abdomen. We performed a MEDLINE and Pubmed search connecting abdominal assessment and critical care. Based on these findings we defined the following major categories of monitoring and diagnostic measures: clinical investigation; assessment of motility and digestive function; microbiome monitoring; perfusion monitoring; laboratory biomarkers and hormonal function; intra-abdominal pressure measurement; and imaging techniques. Only a few of these monitoring and assessment tools have found their way into clinical practice, as most of them have one or more significant objections preventing broad implementation in daily clinical practice. Further research should be directed to reaffirm and define the use of current techniques to ascertain their validity and usefulness to monitor gastrointestinal function in ICU patients.

Abdominal pressure and gastrointestinal function: an inseparable couple?

Evaluating the degree of organ dysfunction is a cornerstone in distinguishing patients with critical illness from those without. However, evaluation of the gastrointestinal function in critically ill patients is not unified, and is still largely based on subjective clinical evaluation. Although intra-abdominal pressure has been proposed as a parameter to facilitate monitoring of abdominal compartment in critical illness, the interactions between intra-abdominal pressure and gastrointestinal function are poorly clarified. The aim of this current review is to describe interactions and associations between gastrointestinal dysfunction and intra-abdominal pressure from a pathophysiological and clinical point of view.

Early enteral nutrition in critically ill patients: ESICM clinical practice guidelines

Purpose

To provide evidence-based guidelines for early enteral nutrition (EEN) during critical illness.

Methods

We aimed to compare EEN vs. early parenteral nutrition (PN) and vs. delayed EN. We defined “early” EN as EN started within 48 h independent of type or amount. We listed, a priori, conditions in which EN is often delayed, and performed systematic reviews in 24 such subtopics. If sufficient evidence was available, we performed meta-analyses; if not, we qualitatively summarized the evidence and based our recommendations on expert opinion. We used the GRADE approach for guideline development. The final recommendations were compiled via Delphi rounds.

Results

We formulated 17 recommendations favouring initiation of EEN and seven recommendations favouring delaying EN. We performed five meta-analyses: in unselected critically ill patients, and specifically in traumatic brain injury, severe acute pancreatitis, gastrointestinal (GI) surgery and abdominal trauma. EEN reduced infectious complications in unselected critically ill patients, in patients with severe acute pancreatitis, and after GI surgery. We did not detect any evidence of superiority for early PN or delayed EN over EEN. All recommendations are weak because of the low quality of evidence, with several based only on expert opinion.

Conclusions

We suggest using EEN in the majority of critically ill under certain precautions. In the absence of evidence, we suggest delaying EN in critically ill patients with uncontrolled shock, uncontrolled hypoxaemia and acidosis, uncontrolled upper GI bleeding, gastric aspirate >500 ml/6 h, bowel ischaemia, bowel obstruction, abdominal compartment syndrome, and high-output fistula without distal feeding access.

Electronic supplementary material

The online version of this article (doi:10.1007/s00134-016-4665-0) contains supplementary material, which is available to authorized users.

Implementation of enteral feeding protocol in an intensive care unit: Before-and-after study

AIM

To determine the effects of implementing an enteral feeding protocol on the nutritional delivery and outcomes of intensive care patients.

METHODS

An uncontrolled, observational before-and-after study was performed in a tertiary mixed medical-surgical intensive care unit (ICU). In 2013, a nurse-driven enteral feeding protocol was developed and implemented in the ICU. Nutrition and outcome-related data from patients who were treated in the study unit from 2011-2012 (the Before group) and 2014-2015 (the After group) were obtained from a local electronic database, the national Population Registry and the hospital’s Infection Control Service. Data from adult patients, readmissions excluded, who were treated for at least 7 d in the study unit were analysed.

RESULTS

In total, 231 patients were enrolled in the Before and 249 in the After group. The groups were comparable regarding demographics, patient profile, and severity of illness. Fewer patients were mechanically ventilated on admission in the After group (86.7% vs 93.1% in the Before group, P = 0.021). The prevalence of hospital-acquired infections, length of ICU stay and ICU, 30- and 60-d mortality did not differ between the groups. Patients in the After group had a lower 90-d (P = 0.026) and 120-d (P = 0.033) mortality. In the After group, enteral nutrition was prescribed less frequently (P = 0.039) on day 1 but significantly more frequently on all days from day 3. Implementation of the feeding protocol resulted in a higher cumulative amount of enterally (P = 0.049) and a lower cumulative amount of parenterally (P < 0.001) provided calories by day 7, with an overall reduction in caloric provision (P < 0.001). The prevalence of gastrointestinal symptoms was comparable in both groups, as was the frequency of prokinetic use. Underfeeding (total calories < 80% of caloric needs, independent of route) was observed in 59.4% of the study days Before vs 76.9% After (P < 0.001). Inclusion in the Before group, previous abdominal surgery, intra-abdominal hypertension and the sum of gastrointestinal symptoms were found to be independent predictors of insufficient enteral nutrition.

CONCLUSION

The use of a nurse-driven feeding protocol improves the delivery of enteral nutrition in ICU patients without concomitant increases in gastrointestinal symptoms or intra-abdominal hypertension.

Mild to moderate intra-abdominal hypertension: Does it matter?

This review summarizes the epidemiology, pathophysiological consequences and impact on outcome of mild to moderate (Grade I to II) intra-abdominal hypertension (IAH), points out possible pitfalls in available treatment recommendations and focuses on tasks for future research in the field. IAH occurs in about 40% of ICU patients. Whereas the prevalence of abdominal compartment syndrome seems to be decreasing, the prevalence of IAH does not. More than half of IAH patients present with IAH grade I and approximately a quarter with IAH grade II. However, most of the studies have addressed IAH as a yes-or-no variable, with little or no attention to different severity grades. Even mild IAH can have a negative impact on tissue perfusion and microcirculation and be associated with an increased length of stay and duration of mechanical ventilation. However, the impact of IAH and its different grades on mortality is controversial. The influence of intra-abdominal pressure (IAP) on outcome most likely depends on patient and disease characteristics and the concomitant macro- and microcirculation. Therefore, management might differ significantly. Today, clear triggers for interventions in different patient groups with mild to moderate IAH are not defined. Further studies are needed to clarify the clinical importance of mild to moderate IAH identifying clear triggers for interventions to lower the IAP.