Improved outcomes in paediatric intestinal failure with aggressive prevention of liver disease

The impact of multi-disciplinary intestinal rehabilitation programs on the outcome of pediatric patients with intestinal failure: a systematic review and meta-analysis

BACKGROUND

Pediatric intestinal failure (IF) is a complex clinical problem requiring coordinated multi-disciplinary care. Our objective was to review the evidence for the benefit of intestinal rehabilitation programs (IRP) in pediatric IF patients.

METHODS

A systematic review was performed on Medline (1950-2012), Pubmed (1966-2012), and Embase (1980-2012) conference proceedings and trial registries. The terms short bowel syndrome, intestinal rehabilitation, intestinal failure, patient care teams, and multi-disciplinary teams were used. Fifteen independent studies were included. Three studies that were cohort studies, including a comparison group, were included in a meta-analysis.

RESULTS

Compared to historical controls (n=103), implementation of an IRP (n=130) resulted in a reduction in septic episodes (0.3 vs. 0.5 event/month; p=0.01) and an increase in overall patient survival (22% to 42%). Non-significant improvements were seen in weaning from PN (RR=1.05, 0.88-1.25, p=0.62), incidence of IFALD (RR=0.2, 0-17.25, p=0.48), and relative risk of liver transplantation (3.99, 0.75-21.3, p=0.11). Other outcomes reported included a reduction in calories from parenteral nutrition (100% to 32%-56%), earlier surgical/transplant evaluation, and improved coordination of patient care.

CONCLUSION

For pediatric IF patients, IRPs are associated with reduced morbidity and mortality. Standardized clinical practice guidelines are necessary to provide uniform patient care and outcome assessment.

Review and clinical update on parenteral nutrition-associated liver disease

Parenteral nutrition-associated liver disease (PNALD) is a complex disease that is diagnosed by clinical presentation, biochemical markers of liver injury, concurrent use of parenteral nutrition (PN), and negative workup for other causes of liver disease. Since the first case of PNALD was reported more than 30 years ago, clinicians have had few effective treatments for PNALD, and when disease progressed to liver cirrhosis, it was historically associated with poor outcomes. Within the past 5 years, there has been much excitement about new treatments for PNALD, including use of both parenteral and enteral ω-3 polyunsaturated long-chain fatty acids (ω-3 PUFA) as well as restricting dosing of ω-6 PUFA. Scientists are also interested in uncovering the mechanisms associated with liver injury seen in PNALD. This article reviews the recent literature relating to the pathophysiology and treatment of PNALD.

Provision of a soy-based intravenous lipid emulsion at 1 g/kg/d does not prevent cholestasis in neonates

BACKGROUND

One of the most common and severe complications of long-term parenteral nutrition (PN) is PN-associated cholestasis. The soybean oil-based lipid emulsion administered with PN has been associated with cholestasis, leading to an interest in lipid reduction strategies. The purpose of this study was to determine whether the provision of a soybean oil-based lipid emulsion at 1 g/kg/d compared with 2-3 g/kg/d is associated with a reduced incidence of cholestasis.

METHODS

Retrospective review of neonates admitted between 2007 and 2011 with a gastrointestinal condition necessitating ≥ 21 days of PN support. Neonates were divided into 2 groups based on the intravenous lipid emulsion dose: 1-g group (1 g/kg/d) and 2- to 3-g group (2-3 g/kg/d). The primary outcome measure was the incidence of cholestasis.

RESULTS

Sixty-one patients met inclusion criteria (n = 29, 1-g group; n = 32, 2- to 3-g group). The 2 groups did not differ in any baseline characteristics other than associated comorbidities that were more common in the 2- to 3-g group. The duration of PN, the number of operative procedures and bloodstream infections, and enteral nutrition (EN) were similar between groups. The incidence of cholestasis was not different between groups (51.7%, 1-g group; 43.8%, 2- to 3-g group; P = .61), and there was no difference between groups in the time to cholestasis (32.6 ± 24.1 days, 1-g group; 27.7 ± 10.6 days, 2- to 3-g group; P = .48). Overall, 44.8% of patients with cholestasis were transitioned to full EN, and 55.2% were transitioned to a fish oil-based lipid emulsion after which the direct bilirubin normalized in all patients.

CONCLUSION

Lipid reduction to 1 g/kg/d does not prevent or delay the onset of cholestasis in neonates.

Chronic intestinal failure in children

BACKGROUND

Chronic intestinal failure (CIF) in childhood is caused by congenital malformations and inflammatory diseases of the gut. Its reported prevalence is 13.7 per million population. Long-term home parenteral nutrition has dramatically improved the life expectancy and quality of life of children with CIF. The affected children are now treated with parenteral nutrition at home as soon as their medical state and family circumstances allow.

METHODS

The authors present data from a patient registry and review publications retrieved by a selective literature search.

RESULTS AND CONCLUSION

Children with CIF can now be expected to survive beyond adolescence, at the very least, and enjoy good quality of life. This goal can only be achieved if nutritional therapy is carried out safely and the affected children's development is closely monitored by an interdisciplinary team that consists of primary care physicians/family doctors, neonatologists, pediatric gastroenterologists, and pediatric surgeons. Moreover, the prevention, early detection, and appropriate treatment of complications such as infection, liver disease, renal dysfunction, and disturbances of bone metabolism is of vital importance. The patients' families must be supported by specially qualified ambulatory nurses and social workers. Treatment with parenteral, enteral, and oral nutrition and surgery enables most infants with CIF to meet all their nutritional needs orally by the time they start going to school. For children who suffer from intractable complications, intestinal transplantation provides a real and increasing chance of survival.

Intravenous fat emulsions reduction for patients with parenteral nutrition-associated liver disease

OBJECTIVE

To test the hypothesis that implementation of a marked reduction in intravenous fat will result in reversal of parenteral nutrition-associated liver disease (PNALD) in infants.

STUDY DESIGN

Prospective study of intravenous fat emulsion reduction in parenteral nutrition to 1 g/kg/d 2 times per week in neonates diagnosed with PNALD. Primary outcome measure was total bilirubin levels compared with gestational age, birth weight, and diagnosis-matched historical controls receiving 3 g/kg/d of intravenous lipids.

RESULTS

Intravenous fat emulsion reduction resulted in a significant decline in total bilirubin levels compared with controls. Comparison of growth in the 2 groups was similar. Mild essential fatty acid deficiency was detected in 8 of 31 infants and was reversed with additional days of lipid infusion. No significant adverse events were noted.

CONCLUSIONS

An association between intravenous lipid emulsion administration and the development of PNALD seems probable. Use of intravenous fat emulsion reduction is a potential approach to reverse PNALD in young infants. Frequent monitoring of essential fatty acid deficiency is needed with the use of this regimen.

Current status of pediatric intestinal failure, rehabilitation, and transplantation: summary of a colloquium

An international symposium convened September 9-11, 2010, in Chicago to present the state of the art and science of the multidisciplinary care of intestinal failure in children. Medical and surgical management of the child with intestinal failure was presented with a focus on the importance of multidisciplinary intestinal failure management. Issues of timing of referral and benefit risk analysis for intestine "rehabilitation" and transplant were presented. Areas of opportunity such as increased donor recovery, improvement of long-term transplant outcomes, optimization of immune monitoring, and quality-of-life outcomes were reviewed.

Improved outcome in neonatal short bowel syndrome using parenteral fish oil in combination with ω-6/9 lipid emulsions

BACKGROUND

Newborn infants with short bowel syndrome (SBS) represent a high-risk group of developing intestinal failure-associated liver disease (IFALD), which may be fatal. However, infants have a great capacity for intestinal growth and adaptation if IFALD can be prevented or reversed. A major contributing factor to IFALD may be the soybean oil-based intravenous lipid emulsions used since the introduction of parenteral nutrition (PN) 40 years ago.

METHODS

This retrospective study compares the outcome in 20 neonates with SBS treated with parenteral fish oil (Omegaven) in combination with ω-6/9 lipid emulsions (ClinOleic) with the outcome in a historical cohort of 18 patients with SBS who received a soybean oil-based intravenous lipid emulsion (Intralipid).

RESULTS

Median gestational age was 26 weeks in the treatment group and 35.5 weeks in the historical group. All patients were started on PN containing Intralipid that was switched to ClinOleic/Omegaven in the treatment group at a median age of 39 gestational weeks. In the treatment group, direct bilirubin levels were reversed in all 14 survivors with cholestasis (direct bilirubin >50 umol/L). Median time to reversal was 2.9 months. Only 2 patients died of liver failure (10%). In the historical cohort, 6 patients (33%) died of liver failure, and only 2 patients showed normalization of bilirubin levels.

CONCLUSIONS

Parenteral fish oil in combination with ω-6/9 lipid emulsions was associated with improved outcome in premature neonates with SBS. When used instead of traditional soybean-based emulsions, this mixed lipid emulsion may facilitate intestinal adaptation by increasing the IFALD-free period.

Early inflammatory markers for prediction of cholestasis in very-low-birth-weight infants

BACKGROUND

Neonatal cholestasis is associated with increased mortality and other adverse outcomes. There are no tools for prediction of infants at risk for cholestasis.

OBJECTIVE

To determine if cholestasis in very-low-birth-weight (VLBW) infants is associated with alterations in cytokines or C-reactive protein (CRP) and, if so, whether inflammatory markers predict which infants will develop cholestasis.

METHODS

VLBW infants expected to be on parenteral nutrition for >7 days were enrolled in this prospective cohort study. Infants with direct bilirubin ≥1.0 mg/dl were considered to have a high risk for cholestasis and were compared to infants who never developed direct bilirubin ≥1.0 mg/dl. Standard descriptive statistics were used to compare biomarkers over time. Multivariable models were used to estimate associations between early inflammatory markers and cholestasis.

RESULTS

Of 63 infants enrolled, 29 were at risk for cholestasis. CRP was highly correlated with direct bilirubin. Infants in the high-risk group had significantly higher IL-1β, IL-6, IL-8, and IL-10 at 2, 4, and 6 weeks and CRP at 2 and 6 weeks. In logistic models, CRP (OR = 4.97, p = 0.02) or IL-1β (OR = 1.11, p = 0.008) at 2 weeks of age was predictive of cholestasis. In linear mixed-effects models, CRP (p < 0.001) or IL-6 (p = 0.02) and IL-8 (p < 0.001) were predictive of cholestasis.

CONCLUSION

Elevated CRP and cytokines are associated with cholestasis in VLBW infants. These inflammatory markers are candidates for further research into the pathogenesis, prediction, and prevention of cholestasis.

Medical management of motility disorders in patients with intestinal failure: a focus on necrotizing enterocolitis, gastroschisis, and intestinal atresia

BACKGROUND

Intestinal failure (IF) is the dependence upon parenteral nutrition to maintain minimal energy requirements for growth and development. It may occur secondary to a loss of bowel length, disorders of motility, or both. Short bowel syndrome (SBS) is a malabsorptive state resulting from surgical resection, congenital defect, or diseases associated with loss of absorptive surface area. A particularly vexing problem is associated with whole bowel and/or segmental intestinal dysmotility. Motility disorders within the context of SBS and IF may relate to rapid intestinal transit secondary to loss of intestinal length, dysmotility associated with loss or poor antegrade peristalsis, or gastroparesis. Therapy may be classified into medical (prokinetic and antidiarrheal agents) and surgical to deal with the overdistended poorly motile bowel.

METHODS

We performed a systematic review of the literature pertaining to IF, SBS, and dysmotility in the pediatric population with gastroschisis, necrotizing enterocolitis, and intestinal atresia. In addition to the available treatment options, we have provided a review of the literature and a summary of the available evidence.

CONCLUSION

Despite relatively poor level of evidence regarding the application of promotility and antidiarrheal medications in patients with SBS and IF, these agents continue to be used. Herein, we provide a review of the physiology and pathophysiology of intestinal motility/dysmotility and available strategies for the use of promotility and antidiarrheal agents in patients with IF/SBS.

Prevention and reversal of intestinal failure-associated liver disease in premature infants with short bowel syndrome using intravenous fish oil in combination with omega-6/9 lipid emulsions

Although premature infants with short bowel syndrome are at the highest risk of developing intestinal failure-associated liver disease (IFALD), they have great capacity for intestinal growth and adaptation if IFALD can be prevented. Conventional soybean oil-based intravenous lipid emulsions have been associated with IFALD. This study presents data on 5 premature neonates with short bowel syndrome treated with a combination of parenteral fish oil- and olive/soybean-based lipid emulsion for periods ranging between 7 and 17 months. Despite an enteral tolerance of less than 50% in 4 of these patients during their first year of life, direct bilirubin levels normalized while on this combination of ClinOleic (Baxter, Maurepas, France)/Omegaven (Fresenius Kabi, Bad Homburg, Germany) at a 1:1 ratio. None of our patients developed irreversible IFALD even though all of them were premature, had undergone multiple major surgical procedures, and had experienced several episodes of sepsis. Thus far, we have not seen any adverse effects of this mixed lipid emulsion in these preterm infants. All 5 patients are growing and developing well and have normal liver function.

Systematic review: medical and nutritional interventions for the management of intestinal failure and its resultant complications in children

BACKGROUND

Intestinal failure (IF) affects a growing number of children due to increasing numbers of preterm infants surviving intestinal resection for necrotising enterocolitis and improving surgical techniques for congenital gut anomalies. Parenteral nutrition (PN) is the mainstay of therapy; enteral nutrition may have trophic effects on the gut.

AIM

To review systematically evidence for the effectiveness of medical and nutritional interventions in the treatment of IF in children.

METHODS

Retrieval of data from studies of patients aged <18 years and receiving >28 days of PN. Outcome measures were improvement in intestinal function, intestinal adaptation, growth, prevention and treatment of IF-associated liver disease, and mortality. Cochrane Database (November 2009), MEDLINE (1950-November 2009) and CINAHL (1982-November 2009) electronic database searches were made using keyword and subject headings (MeSH): IF, Short Bowel Syndrome (SBS), PN and Child. The level of the evidence (EL) was assessed using SIGN (Scottish Intercollegiate Guidelines Network) methodology (http://www.sign.ac.uk).

RESULTS

From 1 607 620 hits, 720 abstracts were reviewed. Thirty-three original articles were included. No studies were of high methodological quality.

CONCLUSIONS

The evidence base for medical and nutritional interventions in paediatric IF is limited and of poor quality. In the absence of randomised-controlled trials, this evidence base can improve through case control and cohort research; and with better multiagency communication, the study of inter-centre differences is possible. Achievable short-term goals would include the study of: optimal ursodeoxycholic usage, novel intralipid formulations, cycled enteral antibiotics, enteral probiotics and new enteral feeding strategies.

Omega-3 Long Chain Polyunsaturated Fatty Acids for Treatment of Parenteral Nutrition–Associated Liver Disease: A Review of the Literature

Parenteral nutrition–associated liver disease (PNALD) is a complex disease that is diagnosed by clinical presentation, biochemical markers of liver injury, concurrent use of parenteral nutrition (PN), and negative workup for other causes of liver disease. For the past 30 years, clinicians have had few effective treatments for PNALD and when disease progressed to liver cirrhosis it was historically associated with poor outcomes. Within the past 5 years there has been some encouraging evidence for the potential benefits of fish oils, rich in omega-3 long-chain polyunsaturated fatty acids (ω3PUFA), in reversing liver injury associated with PN. This article reviews the current literature relating to ω3PUFA and PNALD.

Elements of successful intestinal rehabilitation

PURPOSE

The optimal therapy for intestinal failure (IF) is unknown. The results of a systematic, protocol-driven management strategy by a multidisciplinary team are described.

METHODS

Intestinal failure was defined as bowel length of less than 40 cm or parenteral nutrition (PN) for more than 42 days. A multidisciplinary team and protocol to prevent PN-associated liver disease (PNALD) were instituted in 2006. Data were gathered prospectively with consent and ethics board approval.

RESULTS

From 1998 to 2006, 33 patients were treated (historical cohort) with an overall survival of 72%. Rotating prophylactic antibiotics for bacterial overgrowth were given to 27% of patients; 6% had lipid-sparing PN, and none received fish oil-based lipids. Median time to intestinal rehabilitation was 7 ± 3.1 months, and 27% of patients who developed PNALD died. From 2006 to 2009, 31 patients were treated. Seventy-seven percent received PAB; 60%, lipid-sparing PN; and 47%, parenteral fish oil emulsion. Eighty-seven percent weaned from PN at 3.9 ± 3.8 months, and no patients developed PNALD with 100% survival. Novel lipid therapies were associated with changes in essential fatty acid profile and one case of clinical essential fatty acid deficiency.

CONCLUSION

The institution of a multidisciplinary team and a protocol-driven strategy to prevent PNALD improves survival in IF. Further studies are recommended.

Prevention of parenteral nutrition-associated liver disease: lipid minimization

PURPOSE OF REVIEW

The cause of parenteral nutrition-associated liver disease (PNALD) is unknown. Evidence over the past decade has suggested soybean oil-based intravenous emulsions are a contributing factor to the development of PNALD.

RECENT FINDINGS

This review details the historical and scientific rationale, which associates intravenous lipid emulsion administration and PNALD. The article then reviews our own group's experience with lipid restriction and the reversal of PNALD in neonates on long-term parenteral nutrition. Finally, a clinical approach to restricting soybean-based intravenous lipid emulsions in parenteral nutrition is given.

SUMMARY

An association between intravenous lipid emulsion administration and the development of PNALD seems probable. Strategies to reduce lipid emulsions or develop new, nonsoybean-based lipid emulsions should be considered.

Fish oil containing intravenous lipid emulsions in parenteral nutrition-associated cholestatic liver disease

PURPOSE OF REVIEW

Lipid emulsions containing fish oils have been proposed to improve parenteral nutrition associated cholestasis (PNAC), a very serious complication of prolonged parenteral nutrition occurring particularly in infants and children with intestinal failure. Here, we summarize current data.

RECENT FINDINGS

The cause of PNAC is multifactorial. Prevention is possible by appropriate management, surgical procedures, infection prevention, and optimal parenteral nutrition management. Plausible hypotheses and experimental data support potential benefits of fish oils for treatment and prevention of PNAC. Improvement of PNAC over weeks and months has been reported in observational case studies in part of the children who received parenteral lipids with fish oil, but similar improvements also occurred by withholding or reducing standard lipid emulsions. No controlled trials are available that would allow final conclusions on efficacy and safety of fish oil-based emulsions in PNAC. Concerns exist regarding possible untoward effects and an inadequate supply of n-6 fatty acids with parenteral fish oil only. First data from controlled trials with mixed lipid emulsions containing partly fish oil suggest safety in infants and children and some possible benefits for liver function.

SUMMARY

The observed improvement of PNAC on parenteral lipids with fish oil deserves further exploration. No controlled trials are available, nutritional adequacy and safety of 100% fish oil emulsions are not adequately documented, and currently their use cannot be considered standard care. First data on mixed lipid emulsions with some fish oil are encouraging, and their effects in PNAC should also be explored.

The influence of nutrients, biliary-pancreatic secretions, and systemic trophic hormones on intestinal adaptation in a Roux-en-Y bypass model

PURPOSE

The signals that govern the upregulation of nutrient absorption (adaptation) after intestinal resection are not well understood. A Gastric Roux-en-Y bypass (GRYB) model was used to isolate the relative contributions of direct mucosal stimulation by nutrients, biliary-pancreatic secretions, and systemic enteric hormones on intestinal adaptation in short bowel syndrome.

METHODS

Male rats (350-400 g; n = 8/group) underwent sham or GRYB with pair feeding and were observed for 14 days. Weight and serum hormonal levels (glucagon-like peptide-2 [GLP-2], PYY) were quantified. Adaptation was assessed by intestinal morphology and crypt cell kinetics in each intestinal limb of the bypass and the equivalent points in the sham intestine. Mucosal growth factors and expression of transporter proteins were measured in each limb of the model.

RESULTS

The GRYB animals lost weight compared to controls and exhibited significant adaptive changes with increased bowel width, villus height, crypt depth, and proliferation indices in the alimentary and common intestinal limbs. Although the biliary limb did not adapt at the mucosa, it did show an increased bowel width and crypt cell proliferation rate. The bypass animals had elevated levels of systemic PYY and GLP-2. At the mucosal level, insulin-like growth factor-1 (IGF-1) and basic fibroblast growth factor (bFGF) increased in all limbs of the bypass animals, whereas keratinocyte growth factor (KGF) and epidermal growth factor (EGF) had variable responses. The expression of the passive transporter of glucose, GLUT-2, expression was increased, whereas GLUT-5 was unchanged in all limbs of the bypass groups. Expression of the active mucosal transporter of glucose, SGLT-1 was decreased in the alimentary limb.

CONCLUSIONS

Adaptation occurred maximally in intestinal segments stimulated by nutrients. Partial adaptation in the biliary limb may reflect the effects of systemic hormones. Mucosal content of IGF-1, bFGF, and EGF appear to be stimulated by systemic hormones, potentially GLP-2, whereas KGF may be locally regulated. Further studies to examine the relationships between the factors controlling nutrient-induced adaptation are suggested. Direct contact with nutrients appears to be the most potent factor in inducing mucosal adaptation.

The assessment, and glucagon-like peptide-2 modulation, of intestinal absorption and function

The treatment of patients with short bowel syndrome is hampered by a lack of treatment and measurement methods. This article reviews our evolving understanding of the role of glucagon-like peptide 2 (GLP-2) in controlling the adaptive process. The ability of the remnant intestine to produce GLP-2 appears to be predictive of the adaptive process; exogenous GLP-2 may be a therapy to augment adaptation. Strategies for monitoring patients, including conventional means, such as anthropomorphic measurements, plasma levels of specific nutrients, and vitamins and radiological contrast studies are reviewed. Investigational methods, such as nutrient balance studies, plasma citrulline levels, and the absorption of inert sugars (3-0 methyl glucose, mannitol, and lactulose) are discussed with the evidence to support their use.