Nutrition
Key points
Premature neonates need 100-150 Kcal/kg/d
Term neonates need 100-120 Kcal/kg/d
Critical illness has increased glucose needs, but giving extra exogenous glucose does not reduce endogenous turnover, just increases CO2, thereby increasing ventilation requirements
No need to tightly control glucose in critical illness unless very hyperglycaemic
Micronutrients - needed for growth and metalloenzyme synthesis
Iron - absorbed by duodenum and proximal jejunum
Calcium - absorbed across length of small and large bowel
Zinc - absorbed by all of the small bowel
Zinc deficiency: Scaly rash in perioral area, digits, and buttocks. Also causes hypogonadism, hair loss and poor wound healing. Acrodermatitis enteropathica is rare form of inherited zinc deficiency
Folate - absorbed by duodenum and proximal jejunum
Vitamin B12 - bound by intrinsic factor (secreted by gastric parietal cells) then absorbed in terminal ileum
B12 deficiency causes megaloblastic anaemia and neurological symptoms
Parenteral nutrition
Consider for all children that may be without enteral nutrition for > 1 week
Requires central venous access to give lipid component
TPN blood tests including all major electrolytes should be checked prior to then daily for 1 week once started on PN
Thereafter should be checked twice weekly
Test trace elements for children on PN longer than 30 days
In particular, phosphate and potassium disturbances should be corrected prior to commencing PN due to risk of refeeding syndrome
Mechanism of TPN associated liver disease is uncertain
Likely multifactorial - excess calories, infection (both central line and gut bacterial translocation), interruption of enterohepatic circulation, decreased biliary contractility
Refeeding syndrome
Prolonged fasting depletes body stores of key electrolytes. Refeeding causes increase in blood glucose. Insulin response then causes reduction serum potassium, phosphate and magnesium. Resultant arrhythmias and fluid shifts can be fatal
Is prevented by identifying at risk patients, administering high dose vitamin B, then slow increases in feed
Page edited by Mrs Charnjit Seehra BSc November 2024
References
Ben XM. Nutritional management of newborn infants: practical guidelines. World J Gastroenterol. 2008;14(40):6133-6139. doi:10.3748/wjg.14.6133
Holcomb and Ashcraft’s Pediatric Surgery, 7th edition, 2020, Chapter 1
Piskin E et al. Iron Absorption: Factors, Limitations, and Improvement Methods. ACS Omega. 2022;7(24):20441-20456. Published 2022 Jun 10. doi:10.1021/acsomega.2c01833
Ross AC et al. Dietary Reference Intakes for Calcium and Vitamin D. Washington (DC): National Academies Press (US); 2011. 2, Overview of Calcium
Maares M, Haase H. A Guide to Human Zinc Absorption: General Overview and Recent Advances of In Vitro Intestinal Models. Nutrients. 2020;12(3):762. Published 2020 Mar 13. doi:10.3390/nu12030762
Maxfield L, Shukla S, Crane JS. Zinc Deficiency. [Updated 2023 Jun 28]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing
Visentin M et al. The intestinal absorption of folates. Annu Rev Physiol. 2014;76:251-274. doi:10.1146/annurev-physiol-020911-153251
Vaqar S, Shackelford KB. Pernicious Anemia. [Updated 2023 May 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing
Żalikowska-Gardocka M, Przybyłkowski A. Review of parenteral nutrition-associated liver disease. Clin Exp Hepatol. 2020;6(2):65-73. doi:10.5114/ceh.2019.95528
Mehanna HM, Moledina J, Travis J. Refeeding syndrome: what it is, and how to prevent and treat it. BMJ. 2008;336(7659):1495-1498. doi:10.1136/bmj.a301