Gastrointestinal hormone secretion after surgery in neonates with congenital intestinal anomalies during starvation and introduction of enteral nutrition

Pathogenesis and Management of Intestinal Failure-Associated Liver Disease

Long-term parenteral nutrition (PN) has considerably improved the management of intestinal failure (IF) in children and adults, particularly those with short bowel syndrome; however, it carries a significant risk of hepatotoxicity, specifically, intestinal failure-associated liver disease (IFALD), also known as PN-associated liver disease. This review provides an update on the latest understanding of IFALD pathogenesis, emerging therapies, and ongoing challenges in the management of this complication. A number of factors are associated with the development of IFALD. PN lipid emulsions, phytosterol exposure, bacterial dysbiosis, an altered gut-liver axis, and episodes of sepsis disrupt bile acid homeostasis and promote liver inflammation in the active phase of IFALD, favoring the development of PN-associated cholestasis (PNAC) and the more chronic form of steatohepatitis with fibrosis. Based on the identification of pathophysiological pathways, potential therapies are being studied in preclinical and clinical trials, including lipid emulsion modifications; targeted therapies such as Farnesoid X receptor (FXR) and liver receptor homolog 1 (LRH-1) agonists, tumor necrosis factor inhibitors, glucagon-like peptide-2 analogs; microbiome modulation; and supplementation with choline and antioxidants. In conclusion, the pathogenesis of IFALD is complex, and PN dependence and liver injury remain challenging, particularly in patients with IF who cannot advance to enteral nutrition and be weaned off PN.

The enteroendocrine axis and its effect on gastrointestinal function, nutrition, and inflammation

PURPOSE OF REVIEW

Gastrointestinal (GI) dysfunction limits enteral nutrition (EN) delivery in critical illness and contributes to systemic inflammation. The enteroendocrine (EE) axis plays an integral role in this interface between nutrition, inflammation, and GI function in critical illness. In this review, we present an overview of the EE system with a focus on its role in GI inflammation and function.

RECENT FINDINGS

Enteroendocrine cells have been primarily described in their role in macronutrient digestion and absorption. Recent research has expanded on the diverse functions of EE cells including their ability to sense microbial peptides and metabolites and regulate immune function and inflammation. Therefore, EE cells may be both affected by and contribute to many pathophysiologic states and interventions of critical illness such as dysbiosis , inflammation, and alternative EN strategies. In this review, we present an overview of EE cells including their growing role in nonnutrient functions and integrate this understanding into relevant aspects of critical illness with a focus on EN.

SUMMARY

The EE system is key in maintaining GI homeostasis in critical illness, and how it is impacted and contributes to outcomes in the setting of dysbiosis , inflammation and different feeding strategies in critical illness should be considered.

Current Insights Regarding Intestinal Failure-Associated Liver Disease (IFALD): A Narrative Review

Intestinal failure-associated liver disease (IFALD) is a spectrum of liver disease including cholestasis, biliary cirrhosis, steatohepatitis, and gallbladder disease in patients with intestinal failure (IF). The prevalence of IFALD varies considerably, with ranges of 40-60% in the pediatric population, up to 85% in neonates, and between 15-40% in the adult population. IFALD has a complex and multifactorial etiology; the risk factors can be parenteral nutrition-related or patient-related. Because of this, the approach to managing IFALD is multidisciplinary and tailored to each patient based on the etiology. This review summarizes the current knowledge on the etiology and pathophysiology of IFALD and examines the latest evidence regarding preventative measures, diagnostic approaches, and treatment strategies for IFALD and its associated complications.

New Insights Into Intestinal Failure-Associated Liver Disease in Children

Development of intestinal failure-associated liver disease (IFALD) is a common complication of long-term parenteral nutrition (PN) in children and adults. The molecular and cellular mechanisms and the phases of IFALD are now being delineated. Components of PN lipid emulsions, including plant sterols, interact with hepatic innate immune activation promoted by products of gut bacterial overgrowth/dysbiosis and altered intestinal barrier function (gut-liver axis) and by episodes of sepsis to cause cholestasis and IFALD. New therapeutic strategies, including modifications of intravenous lipid emulsions to reduce pro-inflammatory fatty acids and plant sterol content, can lower the risk of IFALD, reverse cholestasis, and reduce complications, although the significance of persisting hepatic fibrosis is unknown. This review will provide an update on advances in the pathogenesis of IFALD, newer therapeutic and preventative strategies, and challenges that confront managing patients with IFALD.

Gastrointestinal Hormone Profiles Associated With Enteral Nutrition Tolerance and Gastric Emptying in Pediatric Critical Illness: A Pilot Study

BACKGROUND

Enteral nutrition (EN) intolerance and delayed gastric emptying are prevalent in pediatric critical illness and limit EN delivery. Gastrointestinal (GI) hormones may be associated with EN intolerance and delayed gastric emptying in this cohort.

METHODS

We determined GI hormone levels, time to achieve 50% of EN goal, and gastric emptying in critically ill children. Total amylin, active ghrelin, total glucagon-like peptide-1 (GLP-1), total gastric inhibitory polypeptide, glucagon, and total peptide-YY (PYY) were measured by multiplex assay and cholecystokinin by ELISA. Lower concentrations of acetaminophen at 1 hour (C1h, µg/mL) using the acetaminophen absorption test defined delayed gastric emptying. Correlation, regression analyses, and a principal component analysis were used to examine the association between GI hormones and time to 50% EN goal and C1h.

RESULTS

GI hormones were measured in 14 of 21 patients with gastric emptying testing; median age of 11.2 years (6.74-16.3) and 50% male. Increasing hormone levels from GI hormone profile 1 (GLP-1, glucagon, and amylin) correlated with greater time to reach 50% EN goal (R² = 0.296, P = 0.04). Decreasing hormone levels from GI hormone profile 2 (PYY and ghrelin) correlated with lower C1h and slower gastric emptying (R² = 0.342, P = 0.02).

CONCLUSION

GI hormone profiles are associated with time to achieve 50% of EN goal and gastric emptying in critically ill children. We have described a feasible model to study the role of GI hormones in this cohort, including the potential clinical applicability of GI hormone measurement in the management of delayed gastric emptying.

Intestinal failure-associated liver disease: a position paper of the ESPGHAN Working Group of Intestinal Failure and Intestinal Transplantation

Intestinal failure-associated liver disease is the most prevalent complication affecting children with intestinal failure receiving long-term parenteral nutrition. This paper reviews the definition, diagnostic criteria, pathogenesis, and risk factors. The authors discuss the role of enteral nutrition, parenteral nutrition, and its components, especially lipid emulsions. The authors also discuss the surgical treatment, including intestinal transplantation, its indications, technique, and results, and emphasise the importance of specialised intestinal failure centres.

Routine enteral nutrition in neonates on extracorporeal membrane oxygenation

OBJECTIVES

To evaluate over a 5-yr period the feasibility and tolerance of a protocol of routine enteral nutrition in neonates requiring extracorporeal membrane oxygenation (ECMO).

DESIGN

Retrospective medical chart review.

SETTING

Level III children's hospital, pediatric surgical intensive care unit.

PATIENTS

Neonates treated with venoarterial ECMO (VA-ECMO) between January 1997 and January 2002. Patients with congenital diaphragmatic hernia were excluded.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Charts of all neonates treated with VA-ECMO were reviewed. Feasibility was evaluated by recording the time period needed for enteral nutrition to reach 40% of total fluid intake; tolerance was evaluated by reviewing data on enteral nutrition related morbidity. Sixty-seven of the 77 eligible patients received enteral feeding during ECMO. Thirty-six of these patients (54%) received 40% of total fluid intake as enteral nutrition within a median of 3 (range, 2-4) days. Over the years there was a trend toward an increasing usage of enteral nutrition from 71% to 94% (p = .07). Enteral nutrition was temporarily discontinued in 16 patients, with 14 showing gastric retentions, one showing discomfort, and one showing aspiration. Symptoms of bilious vomiting, blood-stained stool, or abdominal distention were not present.

CONCLUSION

Neonates on ECMO in this series tolerated enteral feeding well and did not show serious adverse effects. Overall, it is our experience that routine use of enteral feeding in critically ill neonates on VA-ECMO is feasible.

Gut hormone profiles in critically ill neonates on extracorporeal membrane oxygenation

OBJECTIVES

The objective of this study was to gain insight into the hormonal responses to enteral nutrition in critically ill newborns requiring venoarterial extracorporeal membrane oxygenation (ECMO) by analyzing plasma gut hormone levels of gastrin, cholecystokinin and peptide-YY in relation to enteral nutrition.

METHODS

In 24 consecutive neonates treated with venoarterial ECMO intestinal hormone secretions were determined by radioimmunoassay at 2-day intervals. Twelve received parenteral nutrition only. In 12 enteral nutrition was introduced later. The findings in these patients were compared with those of 16 measurements in eight non-ECMO treated age-matched controls. Mixed model analysis of variance was used for statistical analysis.

RESULTS

Concentrations of gastrin, cholecystokinin and peptide-YY were significantly higher in ECMO patients receiving enteral nutrition compared with ECMO patients who received parenteral nutrition (62, 3.8 and 59.4 pmol/L versus 46, 3.1 and 34.7 pmol/L, respectively). Overall, plasma hormone levels did not differ from those in age-matched controls.

CONCLUSIONS

Intestinal hormone levels showed normal responses after introduction of enteral feeding, comparable with those in age-matched controls without ECMO. These results do not provide an argument for withholding enteral nutrition even in the most severely ill neonates on venoarterial ECMO.