Gastrointestinal dysmotility: clinical consequences and management of the critically ill patient

Identifying potential biomarkers and therapeutic targets for dogs with sepsis using metabolomics and lipidomics analyses

Sepsis is a diagnostic and therapeutic challenge and is associated with morbidity and a high risk of death. Metabolomic and lipidomic profiling in sepsis can identify alterations in metabolism and might provide useful insights into the dysregulated host response to infection, but investigations in dogs are limited. We aimed to use untargeted metabolomics and lipidomics to characterize metabolic pathways in dogs with sepsis to identify therapeutic targets and potential diagnostic and prognostic biomarkers. In this prospective observational cohort study, we examined the plasma metabolomes and lipidomes of 20 healthy control dogs and compared them with those of 21 client-owned dogs with sepsis. Patient data including signalment, physical exam findings, clinicopathologic data and clinical outcome were recorded. Metabolites were identified using an untargeted mass spectrometry approach and pathway analysis identified multiple enriched metabolic pathways including pyruvaldehyde degradation; ketone body metabolism; the glucose-alanine cycle; vitamin-K metabolism; arginine and betaine metabolism; the biosynthesis of various amino acid classes including the aromatic amino acids; branched chain amino acids; and metabolism of glutamine/glutamate and the glycerophospholipid phosphatidylethanolamine. Metabolites were identified with high discriminant abilities between groups which could serve as potential biomarkers of sepsis including 13,14-Dihydro-15-keto Prostaglandin A₂; 12(13)-DiHOME (12,13-dihydroxy-9Z-octadecenoic acid); and 9-HpODE (9-Hydroxyoctadecadienoic acid). Metabolites with higher abundance in samples from nonsurvivors than survivors included 3-(2-hydroxyethyl) indole, indoxyl sulfate and xanthurenic acid. Untargeted lipidomic profiling revealed multiple sphingomyelin species (SM(d34:0)+H; SM(d36:0)+H; SM(d34:0)+HCOO; and SM(d34:1D3)+HCOO); lysophosphatidylcholine molecules (LPC(18:2)+H) and lipophosphoserine molecules (LPS(20:4)+H) that were discriminating for dogs with sepsis. These biomarkers could aid in the diagnosis of dogs with sepsis, provide prognostic information, or act as potential therapeutic targets.

A Systematic Review and Meta-Analysis of the effectiveness of continuous versus intermittent enteral nutrition in critically ill adults

BACKGROUND

Continuous Enteral Nutrition (CEN) remains standard practice in Intensive Care Units (ICUs) worldwide. Intermittent Enteral Nutrition (IEN) may be a suitable alternative method. This meta-analysis aims to investigate the safety, tolerance, and effectiveness of IEN compared to CEN in critically ill adults in the ICU.

METHODS

Medline, CINAHL, Scopus, Embase and Google Scholar were searched for studies published up until 30^th April 2020, along with manual searches in bibliographies. Eligible studies were trials that compared CEN versus IEN feeding in the ICU, and reported on at least one of the relevant outcomes - nutritional intake, gastric residual volume (GRV), aspiration pneumonia, vomiting, diarrhea, abdominal distension, glycemic variability. Secondary outcomes were ICU length of stay (LOS) and mortality. The Cochrane risk-of-bias tool for randomized trials was used to assess methodological quality.

RESULTS

Ten studies with 664 participants were included in the meta-analysis. The majority of studies had an overall 'High' risk of bias. Incidence of vomiting was significantly higher in CEN as compared to IEN groups (Risk Ratio 2.76; 95% CI, 1.23 - 6.23). There were no significant differences between CEN and IEN groups for nutritional intake, GRV, the incidence of aspiration pneumonia, diarrhea, abdominal distension, ICU LOS, and mortality. Definition and reporting of outcome measures were not standardized across studies, hence this heterogeneity limits generalisability of results.

CONCLUSION

Overall, the safety, tolerance, and effectiveness of CEN and IEN were found to be comparable. Future studies should explore monitoring larger sample sizes to determine best feeding practices in ICU. This article is protected by copyright. All rights reserved.

Feeding intolerance score in critically ill patients with enteral nutrition: A post hoc analysis of a prospective study

BACKGROUND

Feeding intolerance (FI) is common in critically ill patients fed with enteral nutrition. Although there is increasing evidence showing the association between FI and mortality, no reliable quantitative assessment was available in clinical practice. In this study, we proposed a FI scoring system based on gastrointestinal (GI) symptoms to assist the implementation of enteral nutrition and assessed its association with 28-day mortality.

METHODS

This is a post hoc analysis based on data collected in a previous cross-sectional study. All adult patients who were enterally fed were included. Various definitions of FI were compared. The area under the receiver operating characteristic (AUROC) was used to assess the predictive performance for 28-day mortality. Pearson correlation coefficient and the variance inflation factor were applied to detect collinearity among variables. Multiple logistic regression analysis was used to determine the risk factors for 28-day mortality.

RESULTS

Of the 1098 patients included, 200 (18.2%) were nonsurvivors. The incidence of GI symptoms was higher in nonsurvivors on the study day. The multiple logistic regression analysis showed that the proposed FI score was an independent risk factor for 28-day mortality (odds ratio [OR]: 1.37; 95% CI, 1.25-1.51; P < .001). Moreover, the FI score showed better predictive accuracy for 28-day mortality than the other definitions (AUROC: 0.633 [95% CI, 0.591-0.675] for the FI score vs 0.595 (95% CI, 0.557-0.633] for the best-performing FI definition [P = 0.001]).

CONCLUSIONS

FI score is independently associated with 28-day mortality in critically ill patients with acceptable predictive accuracy.

Systematic review of clinicians' knowledge, attitudes, and beliefs about nutrition in intensive care

Nutrition is a key component of care for critically ill patients; yet nutrition delivery is below international recommendations. In order to improve nutrition delivery to critically ill patients, an understanding of the barriers that prevent guideline adherence is required. It is known that clinicians' knowledge, attitudes, and beliefs of the role of nutrition may act as a potential barrier to nutrition delivery, but whether this remains true in critical care is unknown. The aim of this systematic scoping review was to summarize the literature exploring the knowledge, attitudes, and beliefs of clinicians around nutrition support in critically ill patients. A search of four online databases (MEDLINE via Ovid, Emcare via Ovid, PsycINFO, and CINAHL via EBSCOhost) was conducted on August 14, 2020, to identify literature that reported on clinicians' knowledge, attitudes, and beliefs of nutrition in adult intensive care patients. Data were extracted on study and participant characteristics, methodology, and key study outcomes related to nutrition. Eighteen articles met eligibility criteria and were included in the review. Key findings included the following: nutrition was seen as a priority that ranked below life-saving interventions; differences in perceived clinician responsibilities exist; common barriers to nutrition delivery included inadequate resourcing, lack of nutrition protocols, and gastrointestinal intolerance; and identified facilitators included nutrition education and the presence of a supportive multidisciplinary team. The implementation of nutrition protocols, enhanced clinical nutrition education, and further clarification of roles and responsibilities pertaining to nutrition may assist in improving nutrition delivery in critical care.

Protein prescription and delivery practices in critically ill adults: A survey of Australian and New Zealand intensive care dietitians

BACKGROUND

Protein provision is thought to be integral to attenuating muscle wasting in critical illness, yet patients receive half of that prescribed. As international guidelines lack definitive evidence to support recommendations, understanding clinicians' views relating to protein practices is of importance.

OBJECTIVES

The objective of this study was to describe Australia and New Zealand intensive care unit (ICU) dietitians' protein prescription and perceived delivery practices in critically ill adults, including common barriers and associations between ICU clinical experience and protein prescriptions for different clinical conditions.

METHODS

A 42-item descriptive quantitative survey of Australian and New Zealand intensive care dietitians was disseminated through nutrition and ICU society e-mailing lists. Data were collected on respondent demographics and reported protein practices including questions related to a multitrauma case study. Data were analysed using descriptive and content analysis and reported as n (%). Fisher's exact tests were used to compare experience and protein prescriptions.

RESULTS

Of the 67 responses received (one excluded due to >50% missing data), more than 80% of respondents stated they would prescribe 1.2-1.5 g protein/kg bodyweight/day for most critically ill patients, most commonly using European Society of Clinical Nutrition and Metabolism (ESPEN) guidelines to support prescriptions (n = 61/66, 92%). Most respondents (n = 49/66, 74%) thought their practice achieved 61-80% of protein prescriptions, with frequently reported barriers including fasting periods (n = 59/66, 89%), avoiding energy overfeeding (n = 50/66, 76%), and gastrointestinal intolerance (n = 47/66, 71%). No associations between years of ICU experience and protein prescriptions for 14 of the 15 predefined clinical conditions were present.

CONCLUSIONS

Australian and New Zealand ICU dietitians use international guidelines to inform protein prescriptions of 1.2-1.5 g/kg/day for most clinical conditions, and protein prescriptions do not appear to be influenced by years of ICU experience. Key perceived barriers to protein delivery including avoidance of energy overfeeding and gastrointestinal intolerance could be explored to improve protein adequacy.

Effects of Standard vs Energy-Dense Formulae on Gastric Retention, Energy Delivery, and Glycemia in Critically Ill Patients

BACKGROUND

Energy-dense formulae are often provided to critically ill patients with enteral feed intolerance with the aim of increasing energy delivery, yet the effect on gastric emptying is unknown. The rate of gastric emptying of a standard compared with an energy-dense formula was quantified in critically ill patients.

METHODS

Mechanically ventilated adults were randomized to receive radiolabeled intragastric infusions of 200 mL standard (1 kcal/mL) or 100 mL energy-dense (2 kcal/mL) enteral formulae on consecutive days in this noninferiority, blinded, crossover trial. The primary outcome was scintigraphic measurement of gastric retention (percentage at 120 minutes). Other measures included area under the curve (AUC) for gastric retention and intestinal energy delivery (calculated from gastric retention of formulae over time), blood glucose (peak and AUC), and intestinal glucose absorption (using 3-O-methyl-D-gluco-pyranose [3-OMG] concentrations). Comparisons were undertaken using paired mixed-effects models. Data presented are mean ± SE.

RESULTS

Eighteen patients were studied (male/female, 14:4; age, 55.2 ± 5.3 years). Gastric retention at 120 minutes was greater with the energy-dense formula (standard, 17.0 ± 5.9 vs energy-dense, 32.5 ± 7.1; difference, 12.7% [90% confidence interval, 0.8%-30.1%]). Energy delivery (AUC₁₂₀ , 13,038 ± 1119 vs 9763 ± 1346 kcal/120 minutes; P = 0.057), glucose control (peak glucose, 10.1 ± 0.3 vs 9.7 ± 0.3 mmol/L, P = 0.362; and glucose AUC₁₂₀ 8.7 ± 0.3 vs 8.5 ± 0.3 mmol/L.120 minutes, P = 0.661), and absorption (3-OMG AUC₁₂₀ , 38.5 ± 4.0 vs 35.7 ± 4.0 mmol/L.120 minutes; P = .508) were not improved with the energy-dense formula.

CONCLUSION

In critical illness, administration of an energy-dense formula does not reduce gastric retention, increase energy delivery to the small intestine, or improve glucose absorption or glucose control; instead, there is a signal for delayed gastric emptying.

Erythropoietin promotes functional recovery in a mouse model of postoperative ileus

BACKGROUND

Dysmotility and postoperative ileus (POI) are major clinical problems after surgical trauma and it is associated with increased intestinal inflammation and oxidative stress. Despite the high occurrence of POI following intra-abdominal surgeries, no effective treatment is currently available. Erythropoietin (EPO) is a multifunctional tissue-protective cytokine with potent anti-inflammatory and anti-oxidative properties, and it is an FDA approved medicine for clinical use. While both EPO and EPO receptors (EPOR) are widely expressed in the gut, the role of EPO in POI is largely unknown. This study was designed to explore the possible beneficial effect of EPO in a mouse model of POI.

METHODS

Mice were subjected to intestinal manipulation to induce standard POI and intestinal transit time was determined at 24-h post-injury with or without EPO treatment (5000 units/kg, once, IP, immediately after intestinal trauma). Intestinal samples were harvested for histological and immunohistochemical analysis.

RESULTS

Systemic EPO significantly improved intestinal transit time compared with control group and it was associated with significantly increased levels of tissue macrophages and reduced levels of oxidative stress.

CONCLUSIONS AND INFERENCES

This is the first pre-clinical study to document novel beneficial effects of EPO in gut dysmotility and our findings suggest that the beneficial effects of EPO in POI is predominantly mediated by its anti-oxidative and immunomodulatory properties.

Clinical Sequelae From Overfeeding in Enterally Fed Critically Ill Adults: Where Is the Evidence?

Enteral energy delivery above requirements (overfeeding) is believed to cause adverse effects during critical illness, but the literature supporting this is limited. We aimed to quantify the reported frequency and clinical sequelae of energy overfeeding with enterally delivered nutrition in critically ill adult patients. A systematic search of MEDLINE, EMBASE, and CINAHL from conception to November 28, 2018, identified clinical studies of nutrition interventions in enterally fed critically ill adults that reported overfeeding in 1 or more study arms. Overfeeding was defined as energy delivery > 2000 kcal/d, > 25 kcal/kg/d, or ≥ 110% of energy prescription. Data were extracted on methodology, demographics, prescribed and delivered nutrition, clinical variables, and predefined outcomes. Cochrane "Risk of Bias" tool was used to assess the quality of randomized controlled trials (RCTs). Eighteen studies were included, of which 10 were randomized (n = 4386 patients) and 8 were nonrandomized (n = 223). Only 4 studies reported a separation in energy delivery between treatment groups whereby 1 arm met the definition of overfeeding, which reported no between-group differences in mortality, infectious complications, or ventilatory support. Overfeeding was associated with increased insulin administration (median 3 [interquartile range: 0-41.8] vs 0 [0-30.6] units/d) and upper-gastrointestinal intolerance in 1 large RCT and with duration of antimicrobial therapy in a small RCT. There are limited high-quality data to determine the impact of energy overfeeding of critically ill patients by the enteral route; however, based on available evidence, overfeeding does not appear to affect mortality or other important clinical outcomes.

Early enteral nutrition supplemented with probiotics improved the clinical outcomes in severe head injury: Some promising findings from Chinese patients

BACKGROUND

The role of early enteral nutrition (ENN) supplemented with probiotics (<48 hours) in improving clinical outcomes of patients with severe head injury (SHI) remains controversial. We performed this meta-analysis to investigate the efficacy of EEN supplemented with probiotics on clinical outcomes in these patients.

METHODS

Systematic searches were performed in PubMed, Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure, Wanfang database, and Chinese Biomedical Literature to identify potential studies. Two investigators checked citations, extracted data, appraised risk of bias, and then STATA 12.0 was used to perform statistical analysis.

RESULTS

A total of 18 trials were eventually included in the present study. Meta-analysis indicated that EEN supplemented with probiotics was associated with decreased risk of infection (risk ratio [RR], 0.53; 95% confidence interval [CI], 0.44-0.65), decreased risk of mortality (RR, 0.56; 95% CI, 0.38-0.82), decreased risk of gastrointestinal complications (RR, 0.19; 95% CI, 0.13-0.25), and shortened stays in intensive care unit (ICU) (mean difference [MD], -4.55; 96% CI, -5.91 to -3.19).

CONCLUSION

EEN supplemented with probiotics may be a promising alternative for patients with SHI because it effectively decreased the risk of infection, mortality, and gastrointestinal complications, as well as shortened the stays in ICU.

Pathophysiology of Acute Illness and Injury

The pathophysiology of acute illness and injury recognizes three main effectors: infection, trauma, and ischemia-reperfusion injury. Each of them can act by itself or in combination with the other two in developing a systemic inflammatory reaction syndrome (SIRS) that is a generalized reaction to the morbid event. The time course of SIRS is variable and influenced by the number and severity of subsequent insults (e.g., reparative surgery, acquired hospital infections). It occurs simultaneously with a complex of counter-regulatory mechanisms (compensatory anti-inflammatory response syndrome, CARS) that limit the aggressive effects of SIRS. In adjunct, a progressive dysfunction of the acquired (lymphocytes) immune system develops with increased risk for immunoparalysis and associated infectious complications. Both humoral and cellular effectors participate to the development of SIRS and CARS. The most important humoral mediators are pro-inflammatory (IL-1β, IL-6, IL-8, IL-12) and anti-inflammatory (IL-4, IL-10) cytokines and chemokines, complement, leukotrienes, and PAF. Effector cells include neutrophils, monocytes, macrophages, lymphocytes, and endothelial cells. The endothelium is a key factor for production of remote organ damage as it exerts potent chemo-attracting effects on inflammatory cells, allows for leukocyte trafficking into tissues and organs, and promotes further inflammation by cytokines release. Moreover, the loss of vasoregulatory properties and the increased permeability contribute to the development of hypotension and tissue edema. Finally, the disseminated activation of the coagulation cascade causes the widespread deposition of microthrombi with resulting maldistribution of capillary blood flow and ultimately hypoxic cellular damage. This mechanism together with increased vascular permeability and vasodilation is responsible for the development of the multiple organ dysfunction syndrome (MODS).

The Effects of Gastrointestinal Function on the Incidence of Ventilator-associated Pneumonia in Critically Ill Patients

Objective

To investigate the effect of gastrointestinal function on the incidence of ventilator-associated pneumonia (VAP) in critically ill patients.

Methods

From August 2012 to June 2016, 160 critically ill patients in the ICU (Intensive Care Unit) of our hospital were selected as the research group; patients were divided equally into an observation group and a control group, 80 patients in each group, based on the random draw envelope principle. The control group was given a nasogastric tube for gastric feeding, the observation group was given a dual lumen gastrointestinal enteral device for gastric feeding; the two groups’ enteral nutrition observation time was 7d; any changes in patient condition and prognosis were recorded.

Results

The pH value of gastric juice in the control group and the observation group was 6.13±1.38 and 4.01±1.83, respectively: the pH for the observation group was significantly lower than that of the control group (t=4.982, P<0.05). The incidence of VAP in the observation group and the control group was 2.5% and 12.5%, respectively: the VAP for the observation group was significantly lower than that of the control group (P<0.05). The serum levels of pre-albumin and albumin after feeding in the two groups were significantly higher than before feeding (P<0.05); the serum levels of pre-albumin and albumin in the observation group after feeding were significantly higher than those in the control group (P<0.05). The mechanical ventilation time and ICU length of stay in the observation group were 9.12±2.13 days and 12.76±1.98 days, respectively, significantly lower than those of the control group of 10.56±2.89 days and 16.33±2.11 days (P<0.05).

Conclusion

Obstacles to gastrointestinal function in critically ill ICU patients are common; enteral gastric feeding by dual lumen gastrointestinal for can improve the patient’s nutritional status, promote and maintain the normal pH value of gastric juice, thereby reducing the incidence of VAP through rehabilitation of patients.

A retrospective evaluation of nutrition support in relation to clinical outcomes in critically ill patients with an open abdomen

BACKGROUND

Optimising nutrition support in critically ill patients with an open abdomen is challenging.

OBJECTIVES

The aims of this study were to (i) quantify the amount and adequacy of nutrition support administered and (ii) determine any relationships that exist between mode of nutrition support delivery and clinical outcomes in critically ill patients with an open abdomen.

METHODS

A retrospective review of critically ill patients mechanically ventilated for at least 48 h with an open abdomen in a mixed quaternary referral intensive care unit. Enteral and parenteral nutrition (ml) administered daily to patients was recorded for up to 21 days. Length of stay in the intensive care unit and hospital and duration of mechanical ventilation (days) were reported.

RESULTS

Thirty patients were studied [14 male, 68 y (15-90 y), body mass index 25 kg/m² (11-51 kg/m²), Acute Physiology and Chronic Health Evaluation II score 20 (7-41), energy goal 1860 kcal/d (1250-2712 kcal/d)]. Patients received 55% (0-117%) of energy goal and 56% (0-105%) protein goal from either enteral or parenteral nutrition. When enteral nutrition was delivered alone or in combination with parenteral nutrition, patients received 48% (0-146%) of their energy and 59% (19-105%) of their protein goal. Patients fed parenteral nutrition, either alone or as supplementary to enteral nutrition (n = 18), received more energy when compared with those who only received enteral nutrition (n = 9) [65 (27-117) vs 49 (15-89) % energy goal, P = 0.025]. Parenteral nutrition was associated with an increased length of stay in hospital [63 (45-156) vs 45 (17-93) d, P = 0.037].

CONCLUSION

Patients with an open abdomen receive about half of their nutrition requirements when fed exclusively via the enteral route. Providing combination enteral and parenteral nutrition to reach nutritional goals may not result in better clinical outcomes for patients with an open abdomen.

Gastrointestinal dysmotility in critically ill patients

Gastrointestinal (GI) motility disorders are commonly present in critical illness. Up to 60% of critically ill patients have been reported to experience GI dysmotility of some form necessitating therapeutic intervention. It has been attributed to various factors, related to both the underlying disease and the therapeutic interventions undertaken. The assessment of motility disturbances can be challenging in critically ill patients, as the available tests used to detect abnormal motility have major limitations in the setting of an Intensive Care Unit. Critically ill patients with GI dysmotility require a multifaceted treatment approach that addresses multiple causes and utilizes multiple pharmacological pathways. In this review, we discuss the pathophysiology, assessment and management of GI dysmotility in critically ill patients.

Effect of Intravenous Fluids and Analgesia on Dysmotility in Patients With Acute Pancreatitis: A Prospective Cohort Study

OBJECTIVES

Analgesia and intravenous fluid resuscitation are cornerstones of initial patient management in acute pancreatitis (AP). The aim was to investigate the effect of intravenous fluids and analgesia on gastrointestinal motility in the early course of AP.

METHODS

Gastrointestinal dysmotility was assessed using the Gastroparesis Cardinal Symptom Index (GCSI). One-way analysis of variance and analysis of covariance were conducted, adjusting for age, sex, body mass index, severity of AP, preexisting diabetes mellitus, and time from first symptom onset to hospital admission.

RESULTS

A total of 108 patients with AP were prospectively enrolled. Opioid analgesia, when compared with nonopioid analgesia, was significantly associated with increase in total GCSI score in both unadjusted and adjusted analyses. There was no significant difference between aggressive and nonaggressive fluid resuscitation in both unadjusted and adjusted analyses. A combination of opioids and any intravenous fluids was associated with a significantly increased total GCSI score compared with opioids and no intravenous fluids in both unadjusted and adjusted analyses. Duration of symptoms was the confounder that significantly affected 6 of 9 studied associations.

CONCLUSIONS

Intravenous fluids and analgesia significantly affect motility independent of severity and other covariates. Guidelines on prudent use of opioids and fluids in AP need to be developed, particularly taking into account duration of symptoms from onset to hospitalization.

Post-pyloric feeding tube placement in critically ill patients: Extending the scope of practice for Australian dietitians

AIM

To determine whether the placement of a post-pyloric feeding tube (PPFT) can be taught safely and effectively to a critical care dietitian.

METHODS

This is a prospective observational study conducted in an adult intensive care unit (ICU). The intervention consisted of 19 attempts at post-pyloric intubation by the dietitian. The 10 'learning' attempts were performed by the dietitian under the direction of an experienced (having completed in excess of 50 successful tube placements) user. A subsequent nine 'consolidation' attempts were performed under the responsibility of the intensive care consultant on duty. The primary outcome measures were success (i.e. tip of the PPFT being visible in or distal to the duodenum on X-ray) and time (minutes) to PPFT placement. Patients were observed for adverse events per standard clinical practice.

RESULTS

A total of 19 post-pyloric tube placements were attempted in 18 patients (52 (23-70) years, ICU admission diagnoses: trauma n = 4; respiratory failure n = 3; and burns, pancreatitis and renal failure n = 2 each). No adverse events occurred. Most (75%) patients were sedated, and mechanically ventilated. Prokinetics were used to assist tube placement in 11% (2/19) of attempts, both of which were successful. Placement of PPFT was successful in 58% (11/19) of attempts. Whilst training, the success rate was 40% (4/10) compared with 78% (7/9) once training was consolidated (P = 0.17). In the successful attempts, the mean time to placement was 11.0 minutes (3.9-27.1 minutes).

CONCLUSIONS

A dietitian can be trained to safely and successfully place PPFT in critically ill patients.

Energy-Dense Formulae May Slow Gastric Emptying in the Critically Ill

BACKGROUND

Enteral feed intolerance occurs frequently in critically ill patients and can be associated with adverse outcomes. "Energy-dense formulae" (ie, >1 kcal/mL) are often prescribed to critically ill patients to reduce administered volume and are presumed to maintain or increase calorie delivery. The aim of this study was to compare gastric emptying of standard and energy-dense formulae in critically ill patients.

METHODS

In a retrospective comparison of 2 studies, data were analyzed from 2 groups of patients that received a radiolabeled 100-mL "meal" containing either standard calories (1 kcal/mL) or concentrated calories (energy-dense formulae; 2 kcal/mL). Gastric emptying was measured using a scintigraphic technique. Radioisotope data were collected for 4 hours and gastric emptying quantified. Data are presented as mean ± SE or median [interquartile range] as appropriate.

RESULTS

Forty patients were studied (n = 18, energy-dense formulae; n = 22, standard). Groups were well matched in terms of demographics. However, patients in the energy-dense formula group were studied earlier in their intensive care unit admission (P = .02) and had a greater proportion requiring inotropes (P = .002). A similar amount of calories emptied out of the stomach per unit time (P = .57), but in patients receiving energy-dense formulae, a greater volume of meal was retained in the stomach (P = .045), consistent with slower gastric emptying.

CONCLUSIONS

In critically ill patients, the administration of the same volume of a concentrated enteral nutrition formula may not result in the delivery of more calories to the small intestine over time because gastric emptying is slowed.

Gastric Versus Small Bowel Feeding in Critically Ill Adults

Critically ill patients often require enteral feedings as a primary supply of nutrition. Whether enteral nutrition (EN) should be delivered as a gastric versus small bowel feeding in the critically ill patient population remains a contentious topic. The Society of Critical Care Medicine (SCCM)/American Society for Parenteral and Enteral Nutrition (ASPEN), the European Society for Parenteral and Enteral Nutrition (ESPEN), and the Canadian Clinical Practice Guidelines (CCPG) are not in consensus on this topic. No research to date demonstrates a significant difference between the two feeding routes in terms of patient mortality, ventilator days, or length of stay in the intensive care unit (ICU); however, studies provide some evidence that there may be other benefits to using a small bowel feeding route in critically ill patients. The purpose of this paper is to examine both sides of this debate and review advantages and disadvantages of both small bowel and gastric routes of EN. Practical issues and challenges to small bowel feeding tube placement are also addressed. Finally, recommendations are provided to help guide the clinician when selecting a feeding route, and suggestions are made for future research.

Enhanced Protein-Energy Provision via the Enteral Route Feeding (PEPuP) protocol in critically ill surgical patients: a multicentre prospective evaluation

Suboptimal levels of feeding in critically ill patients are associated with poor clinical outcomes. The Enhanced Protein-Energy Provision via the Enteral Route Feeding (PEPuP) protocol was developed to improve nutritional delivery in the critically ill and has been studied in several hospitals. However, the experience with this protocol in surgical patients is limited to date. The objective of this analysis was to describe the experience with this protocol in surgical patients. We analysed observational patient data obtained from the 2013 International Nutrition Survey. We compared nutritional practices and outcomes of patients admitted for surgical and medical reasons to ICUs in sites that implemented the PEPuP protocol. We used surgical ICU patients in non-PEPuP sites as a concurrent control group. In sites that implemented the PEPuP protocol, surgical patients received a smaller proportion of prescribed calories (43% versus 61%, P=0.004) and protein (38% versus 57%, P=0.002) compared to medical patients. When compared to the cohort of surgical patients from control sites, the surgical patients from PEPuP sites received similar amounts of calories and protein. Although surgical PEPuP patients were more likely to receive trophic and volume-based feeds compared to surgical patients in control sites, other aspects of the PEPuP protocol were not adequately implemented. We conclude that nutritional delivery to surgical patients remains inadequate and the PEPuP protocol seems ineffective in improving nutritional intake in this population. Further research to determine methods of optimising PEPuP protocol implementation and adherence in surgery patients is needed.

Nutrition support practices in critically ill head-injured patients: a global perspective

Background

Critical illness following head injury is associated with a hypermetabolic state but there are insufficient epidemiological data describing acute nutrition delivery to this group of patients. Furthermore, there is little information describing relationships between nutrition and clinical outcomes in this population.

Methods

We undertook an analysis of observational data, collected prospectively as part of International Nutrition Surveys 2007-2013, and extracted data obtained from critically ill patients with head trauma. Our objective was to describe global nutrition support practices in the first 12 days of hospital admission after head trauma, and to explore relationships between energy and protein intake and clinical outcomes. Data are presented as mean (SD), median (IQR), or percentages.

Results

Data for 1045 patients from 341 ICUs were analyzed. The age of patients was 44.5 (19.7) years, 78 % were male, and median ICU length of stay was 13.1 (IQR 7.9-21.6) days. Most patients (94 %) were enterally fed but received only 58 % of estimated energy and 53 % of estimated protein requirements. Patients from an ICU with a feeding protocol had greater energy and protein intakes (p <0.001, 0.002 respectively) and were more likely to survive (OR 0.65; 95 % CI 0.42-0.99; p = 0.043) than those without. Energy or protein intakes were not associated with mortality. However, a greater energy and protein deficit was associated with longer times until discharge alive from both ICU and hospital (all p <0.001).

Conclusion

Nutritional deficits are commonplace in critically ill head-injured patients and these deficits are associated with a delay to discharge alive.

Gastric Dysmotility in Critically Ill Children: Pathophysiology, Diagnosis, and Management

OBJECTIVE

We aimed to review gastric dysmotility in critically ill children: 1) its pathophysiology, with a focus on critical care diseases and therapies that affect gastric motility, 2) diagnostic methodologies, and 3) current and future potential therapies.

DATA SOURCES

Eligible studies were identified from PubMed and MEDLINE.

STUDY SELECTION

Literature search included the following key terms: "gastric emptying," "gastric motility/dysmotility," "gastrointestinal motility/dysmotility," "nutrition intolerance," and "gastric residual volume."

DATA EXTRACTION

Studies since 1995 were extracted and reviewed for inclusion by the authors related to the physiology, pathophysiology, diagnostic methodologies, and available therapies for gastric emptying.

DATA SYNTHESIS

Delayed gastric emptying, a common presentation of gastric dysmotility, is present in up to 50% of critically ill children. It is associated with the potential for aspiration, ventilator-associated pneumonia, and inadequate delivery of enteral nutrition and may affect the efficacy of enteral medications, all of which may be result in poor patient outcomes. Gastric motility is affected by critical illness and its associated therapies. Currently available diagnostic tools to identify gastric emptying at the bedside have not been systematically studied and applied in this cohort. Gastric residual volume measurement, used as an indirect marker of delayed gastric emptying in PICUs around the world, may be inaccurate.

CONCLUSIONS

Gastric dysmotility is common in critically ill children and impacts patient safety and outcomes. However, it is poorly understood, inadequately defined, and current therapies are limited and based on scant evidence. Understanding gastric motility and developing accurate bedside measures and novel therapies for gastric emptying are highly desirable and need to be further investigated.

Acid and Weakly Acidic Gastroesophageal Reflux and Pepsin Isoforms (A and C) in Tracheal Secretions of Critically Ill Children

BACKGROUND

Gastroesophageal reflux (GER) and pulmonary aspiration are frequent in patients in the ICU. The presence of pepsin in airways seems to be the link between them. However, pepsin isoforms A (gastric specific) and C (pneumocyte potentially derived) need to be distinguished. This study aimed to evaluate GER patterns and to determine the presence of pepsin A and C in tracheal secretions of critically ill children receiving mechanical ventilation.

METHODS

All patients underwent combined multichannel intraluminal impedance-pH (MII-pH) monitoring. Tracheal secretion samples were collected to determine the presence of pepsin. Pepsin A and C were evaluated by Western blot. MII-pH parameters analyzed were number of total GER episodes (NGER); acid, weakly acidic, and weakly alkaline GER episodes; and proximal and distal GER episodes.

RESULTS

Thirty-four patients (median age, 4 months; range, 1-174 months) were included. MII-pH monitoring detected 2,172 GER episodes (77.0% were weakly acidic; 71.7% were proximal). The median NGER episodes per patient was 59.5 (25th-75th percentile, 20.3-85.3). Weakly acidic GER episodes per patient were significantly more frequent than acid GER episodes per patient (median [25th-75th percentile], 43.5 [20.3-68.3] vs 1.0 [0-13.8], respectively; P < .001). Only three patients had an altered acid reflux index (44.9%, 12.7%, and 13.6%) while not taking antacid drugs. Pepsin A was found in 100% of samples and pepsin C in 76.5%.

CONCLUSIONS

The majority of GER episodes of children in the ICU were proximal and weakly acidic. All patients had aspiration of gastric contents as detected by pepsin A in tracheal fluid. A specific pepsin assay should be performed to establish gastropulmonary aspiration because pepsin C was found in > 70% of samples.

Randomized study to compare nasojejunal with nasogastric nutrition in critically ill patients without prior evidence of altered gastric emptying

BACKGROUND AND AIMS

Studies comparing jejunal and gastric nutrition show inconsistent results regarding pneumonia. The aim of this study was to evaluate the incidence of pneumonia comparing gastric with jejunal nutrition. Secondarily, we evaluated 28(th) day Intensive Care Unit (ICU) mortality rate and other complications related to enteral feeding.

SUBJECTS

Age >18 years; need for enteral nutrition without contraindication for placement of an enteral tube, duration of ICU stay > than 48 h.

METHODS

Patients were randomly assigned to receive enteral feed via a gastric or jejunal tube. Jejunal tubes were inserted at bedside and placement was confirmed radiographically.

RESULTS

A total of 115 patients were enrolled, with 61 patients into the gastric tube group and 54 patients into the jejunal group tube. Baseline characteristics were similar. There was no difference in pneumonia or ICU mortality rates, ICU length of stay and ventilator days. Complications rates were similar.

CONCLUSIONS

We conclude that the enteral nutrition through a jejunal tube does not reduce the rate of pneumonia in comparison to a gastric tube. In addition, we did not observe differences in rates of gastrointestinal complications or ICU mortality. The routine placement of a jejunal tube in critically ill-patients cannot be recommended.

Gastric residual volume in critically ill patients: a dead marker or still alive?

Early enteral nutrition (EN) is consistently recommended as first-line nutrition therapy in critically ill patients since it favorably alters outcome, providing both nutrition and nonnutrition benefits. However, critically ill patients receiving mechanical ventilation are at risk for regurgitation, pulmonary aspiration, and eventually ventilator-associated pneumonia (VAP). EN may increase these risks when gastrointestinal (GI) dysfunction is present. Gastric residual volume (GRV) is considered a surrogate parameter of GI dysfunction during the progression of enteral feeding in the early phase of critical illness and beyond. By monitoring GRV, clinicians may detect patients with delayed gastric emptying earlier and intervene with strategies that minimize or prevent VAP as one of the major risks of EN. The value of periodic GRV measurements with regard to risk reduction of VAP incidence has frequently been questioned in the past years. Increasing the GRV threshold before interrupting gastric feeding results in marginal increases in EN delivery. More recently, a large randomized clinical trial revealed that abandoning GRV monitoring did not negatively affect clinical outcomes (including VAP) in mechanically ventilated patients. The results have revived the discussion on the role of GRV monitoring in critically ill, mechanically ventilated patients receiving early EN. This review summarizes the most recent clinical evidence on the use of GRV monitoring in critically ill patients. Based on the clinical evidence, it discusses the pros and cons and further addresses whether GRV is a dead marker or still alive for the nutrition management of critically ill patients.

High-resolution manometry for the evaluation of gastric motility

This review focus on the utility of HRM for the evaluation of gastric motility. The evaluation of gastric motility has clinical implications for the study of a myriad of diseases. Disordered motility represents a spectrum of dysfunction ranging from delayed gastric emptying to abnormally rapid gastric transit. Gastric motility may be measured by a variety of methods with different efficacy and different variables that may be obtained. High-resolution manometry was created and added to the diagnostic armamentarium. The methods and outcomes for the study of proximal motility that may be useful to assess the thoracoabdominal pressure gradient, gastric filling and accommodation are described. Also, studies on antroduodenal manometry are reviewed. High-resolution manometry allows gastric manometry without technical limitations found on conventional manometry; however, studies are still on the phase of understanding the normal findings.

Multiple organ dysfunction syndrome in humans and animals

Multiple organ dysfunction syndrome (MODS), defined as the presence of altered organ function in an acutely ill patient such that homeostasis cannot be maintained without intervention, is a cause of high morbidity and mortality in humans and animals. Many advances have been made in understanding the pathophysiology and treatment of this syndrome in human medicine, but much still is unknown. This comparative review will provide information regarding the history and pathophysiology of MODS in humans and discuss how MODS affects each major organ system in animals.

Prevalence, risk factors, clinical consequences, and treatment of enteral feed intolerance during critical illness

BACKGROUND

We aimed to determine the incidence of enteral feed intolerance and factors associated with intolerance and to assess the influence of intolerance on nutrition and clinical outcomes.

METHODS

We conducted a retrospective analysis of data from an international observational cohort study of nutrition practices among 167 intensive care units (ICUs). Data were collected on nutrition adequacy, ventilator-free days (VFDs), ICU stay, and 60-day mortality. Intolerance was defined as interruption of enteral nutrition (EN) due to gastrointestinal (GI) reasons (large gastric residuals, abdominal distension, emesis, diarrhea, or subjective discomfort). Logistic regression was used to determine risk factors for intolerance and their clinical significance. A sensitivity analysis restricted to sites specifying a gastric residual volume ≥200 mL to identify intolerance was also conducted.

RESULTS

Data from 1,888 ICU patients were included. The incidence of intolerance was 30.5% and occurred after a median 3 days from EN initiation. Patients remained intolerant for a mean (±SD) duration of 1.9 ± 1.3 days . Intolerance was associated with worse nutrition adequacy vs the tolerant (56% vs 64%, P < .0001), fewer VFDs (2.5 vs 11.2, P < .0001), increased ICU stay (14.4 vs 11.3 days, P < .0001), and increased mortality (30.8% vs 26.2, P = .04). The sensitivity analysis demonstrated that intolerance remained associated with negative outcomes. Although mortality was greater among the intolerant patients, this was not statistically significant.

CONCLUSIONS

Intolerance occurs frequently during EN in critically ill patients and is associated with poorer nutrition and clinical outcomes.

Comparison of postpyloric tube feeding and gastric tube feeding in intensive care unit patients: a meta-analysis

BACKGROUND AND OBJECTIVE

Enteral feeding is vital in the critical care setting; however, the optimal route of enteral feeding (postpyloric vs gastric feeding) remains debated. We aimed to systematically review the current evidence to see whether postpyloric feeding could provide additional benefits to intensive care unit (ICU) patients.

METHOD

Randomized controlled trials (RCTs) comparing the efficacy and safety of postpyloric feeding vs gastric feeding were included in our systematic review. Odds ratio (OR) was used for binary outcome data and weighted mean difference (WMD) was used for continuous outcome data. Summary effects were pooled using a fixed or random effects model as appropriate.

RESULTS

Seventeen RCTs were included in our meta-analysis. Postpyloric tube feeding could deliver higher proportions of estimated energy requirement (WMD, 12%; 95% confidence interval [CI], 5%-18%) and reduce the gastric residual volume (GRV) (WMD, -169.1 mL; 95% CI, -291.995 to -46.196 mL). However, the meta-analysis failed to demonstrate any benefits to critically ill patients with postpyloric tube feeding in terms of mortality (OR, 1.05; 95% CI, 0.77-1.44), new-onset pneumonia (OR, 0.77; 95% CI, 0.53-1.13), and aspiration (OR, 1.20; 95% CI, 0.64-2.25). There was no significant publication bias as represented by an Egger's bias coefficient of 0.21 (95% CI, -1.01 to 1.43; P = .7).

CONCLUSION

As compared with gastric feeding, postpyloric feeding is able to deliver higher proportions of the estimated energy requirement and can help reduce the GRV.