Nutritional Requirements in Intestinal Failure Christopher Duggan, MD, MPH Center for Nutrition Center for Advanced Intestinal Rehabilitation (CAIR) Division of Gastroenterology, Hepatology and Nutrition Boston Children s Hospital Harvard Medical School Boston, MA
Intestinal Failure Defined Reduction of functional intestinal mass necessary for adequate digestion and absorption for nutrient, fluid and growth requirements 3 major classifications Short bowel syndrome Motility disorders Intestinal epithelial defects Short Bowel Syndrome Intestinal loss due to acquired or congenital intestinal disease leading to dependence on parenteral nutrition for > 90 days
Just recently, more than 50% of SBS patients either died or underwent transplantation Subjects enrolled from 2000 2004
Outcomes are improving Andorsky BCH 2001 Fallon BCH 2014
Treatment Parenteral and enteral nutrition Mainstay of therapy Micronutrient supplementation Medical therapies for underlying complications Bacterial overgrowth Intestinal inflammation Dysphagia GLP-2 hormone analogs Intestinal lengthening procedures Intestinal transplantation Time allowing natural process of intestinal adaptation
Mechanisms leading to the special nutritional requirement
Mechanisms leading to the special nutritional requirement Massive bowel loss or intestinal dysfunction leads to malabsorption of all 3 classes of macronutrients and all micronutrients, and therefore usually mandates parenteral delivery of nutrients. Type and degree of malabsorption related to extent and location of resection. terminal ileum and B12 duodenum and iron jejunum/ileum and fat, CHO IFALD can further hamper GI digestion with cholestasis and bile acid inadequacy Limited data suggest pancreatic insufficiency can complicate IF
Evidence for nutritional requirement that is different from that of the healthy population
Total parenteral nutrition
Prevalence of micronutrient deficiencies during PN weaning Yang et al., J Pediatr 2011
Prevalence of micronutrient deficiencies during full EN Yang et al., J Pediatr 2011
Evidence for nutritional requirement that is different from that of the healthy population Seems self evident.. but very limited data on this point. Parenteral nutrient requirements are very much derived from empiric observation (weight and height gain; laboratory data). Indeed, the requirements for many nutrients (copper, zinc, others) were demonstrated by exclusions or omissions of these nutrients from parenteral solutions in the early days of PN, with resultant clinically apparent deficiencies. Potentially conditionally essential nutrients: Glutamine Taurine Cysteine Fatty acids Water, sodium Zinc Many others.. What rate of weaning from PN is optimal? Body composition with PN
Is the disease state (or nutrition status or health related outcomes) responsive to a specific nutritional intervention? Specialized nutritional support (parenteral and enteral nutrition) are primarily supportive therapies. SAM Micronutrient deficiencies Cholestatic liver disease (IFALD) seems to be due to a toxicity of phytosterols included in intravenous fat emulsions.
What are the potential complexities (e.g., heterogeneity of responses, non-responses) and why do they occur? Are there specific absorption issues? Studies to determine nutrient needs in IF are made difficult by a number of issues: Rarity of condition Small size of infants and concomitant limited availability of blood volume Lack of valid biomarkers for nutritional status Heterogeneity of intestinal absorptive capacity among subjects Majority of patients are growing children, so ability to perform cross-over studies is limited On the other hand Patients on prolonged PN have taught us much about nutrient needs Patients with end stomas are easy to do balance studies on