Introduction: Caloric needs in children are always problematic since they vary with age and growth. It becomes even more complicated with parenteral nutrition (PN) because intravenous amino-acids are not included in calorie calculation. However, caloric intake in PN is an important means to estimate PN dependency especially if transplantation is considered. In our patients with intestinal failure on home PN (HPN) we express the level of PN dependency using the NPEI/REE ratio^[1] which is the caloric PN intake (non protein energy intake: NPEI) compared to the resting energy expenditure (REE) calculated with Schofield's equation^[2].

Methods: We included consecutive children aged 2-18 yrs with intestinal failure followed in our HPN center during 2015, treated by HPN for more than 12 months, and who had normal longitudinal growth or stable weight if adult height had been reached. Weight, height, age and the individual NP formula at the first outpatient consultation of the year 2015 were used to calculate NPEI (kcal/day), REE (kcal/day) calculated with Schofield's equation^[2], Recommended dietary allowance (RDA) (kcal/day), NPEI/REE ratio (%), NPEI/kg/day (kcal/kg/day), and  NPEI/RDA (%), respectively.
Children were separated into three groups according to their level of PN dependency using the NPEI/REE ratio: group 1: mild PN dependency: NPEI/REE ratio < 80%; group 2: high PN dependency NPEI/REE ratio 80 – 120%; group 3: very high PN dependency NPEI/REE ratio > 120%. We then compared the NPEI/REE ratio to NPEI in kcal/kg/day and to NPEI/RDA ratio in each group.

Results: Seventy-eight children were included in the study. Median age was 9 years old (IQR 3,5-14). Etiology for intestinal failure was short bowel syndrome (SBS) in 38 children, chronic intestinal pseudo-obstruction in 14, congenital enteropathy (CE) in 11, and long-segment Hirschsprung disease (LSHD) in 15. Four children had benefited from an intestinal transplantation but graft had to be removed (1 CE, 3 HD). Main results are shown in table 1.

Conclusion: The PN dependency level was assessed by using the NPEI/REE ratio expressed as a percentage. It allowed us to classify patients into three groups according to their level of PN dependency. PN intake expressed in kcal/kg did not seem relevant because the caloric needs vary according to age. The PN intake expressed as a ratio of RDA did not seem relevant either as it did not reach 100% in very dependent patients, underestimating the dependency.

[1] Abi Nader E, Lambe C, Talbotec C, Pigneur B, Lacaille F, Garnier-Lengline H, Petit LM, Poisson C, Rocha A, Corriol O, Aigrain Y, Chardot C, Ruemmele F, Colomb-jung V, Goulet O. Outcome of home parenteral nutrition in 251 children over a 14-y period: report of a single center. Am J Clin Nutrition 2016; 103: 1327-36
[2] Schofield WN. Predicting basal metabolic, new standards and review of previous work. Hum Nutr Clin Nutr 1985; 11: 5-41