A scoping review of parenteral requirements (macronutrients, fluid, electrolytes and micronutrients) in adults with chronic intestinal failure receiving home parenteral nutrition

Introduction: Home parenteral nutrition (HPN) prescriptions should be individualised in adults with chronic intestinal failure (IF). The aims of the review were to explore HPN requirements and available guidelines and to determine whether adults (≥ 18 years) receive recommended parenteral nutrient doses. Methods: Online databases searches identified empirical evidence (excluding case-reports), reviews and guidelines (Published 2006–2024 in English language). Additional reference lists were hand-searched. Older studies, cited in national guidelines were highlighted to map evidence source. Two reviewers screened 1660 articles independently, with 98 full articles assessed and 78 articles included (of which 35 were clinical studies). Citation tracking identified 12 older studies. Results: A lack of evidence was found assessing parenteral macronutrient (amounts and ratios to meet energy needs), fluid and electrolyte requirements. For micronutrients, 20 case series reported serum levels as biomarkers of adequacy (36 individual micronutrient levels reported). Studies reported levels below (27 out of 33) and above (24 out of 26) reference ranges for single micronutrients, with associated factors explored in 11 studies. Guidelines stated recommended parenteral dosages. Twenty-four studies reported variable proportions of participants receiving HPN dosages outside of guideline recommendations. When associated factors were assessed, two studies showed nutrient variation with type of HPN administered (multichamber or individually compounded bags). Five studies considered pathophysiological IF classification, with patients with short bowel more likely to require individualised HPN and more fluid and sodium. Conclusions: This review highlights substantial evidence gaps in our understanding of the parenteral nutritional requirements of adult receiving HPN. The conclusions drawn were limited by temporal bias, small samples sizes, and poor reporting of confounders and dose. Optimal HPN nutrient dose still need to be determined to aid clinical decision-making and further research should explore characteristics influencing HPN prescribing to refine dosing recommendations.