How much protein and energy are needed to equilibrate nitrogen and energy balances in ventilated critically ill children?
OBJECTIVE
Protein and energy requirements in critically ill children are currently based on insufficient data. Moreover, longitudinal measurements of both total urinary nitrogen (TUN) and resting energy expenditure (REE) are lacking. The aim of this study was to investigate how much protein and energy are needed to equilibrate nitrogen and energy balances in ventilated critically ill children on the basis of daily measurements of TUN, REE and protein and energy intakes. Comparisons were made with the guidelines of the American Society for Parenteral and Enteral Nutrition and the Dietary Reference Intakes.


METHODS
Children with an expected duration of mechanical ventilation ≥72 h were prospectively recruited. TUN was measured by chemiluminescence, and REE was measured by indirect calorimetry. Generalised linear models for longitudinal data were used to study the relation between protein intake and nitrogen balance and to calculate the minimum intake of protein needed to achieve nitrogen equilibrium. A similar approach was used for energy. Results were compared to the recommended values.


RESULTS
Based on 402 measurements performed in 74 children (median age: 21 months), the mean TUN was high at 0.20 (95% CI: 0.20, 0.22) g/kg/d and the REE was 55 (95% CI: 54, 57) kcal/kg/d. Nitrogen and energy balances were achieved with 1.5 (95% CI: 1.4, 1.6) g/kg/d of protein and 58 (95% CI: 53, 63) kcal/kg/d for the entire group, but there were differences among children of different ages. Children required more protein and less energy than the Dietary Reference Intakes.


CONCLUSIONS
In critically ill children, TUN was elevated and REE was reduced during the entire period of mechanical ventilation. Minimum intakes of 1.5 g/kg/d of protein and 58 kcal/kg/d can equilibrate nitrogen and energy balances in children up to 4 years old. Older children require more protein.
Department of Nutrition and Dietetics, School of Health Professions, University of Applied Sciences Western Switzerland (HES-SO), Rue des Caroubiers 25, 1227 Carouge, Geneva, Switzerland. Electronic address: corinne.jotterand@hesge.ch.
Corinne
C
Jotterand Chaparro
Department of Nutrition and Dietetics, School of Health Professions, University of Applied Sciences Western Switzerland (HES-SO), Rue des Caroubiers 25, 1227 Carouge, Geneva, Switzerland. Electronic address: jocelyne.depeyre@hesge.ch.
Jocelyne
J
Laure Depeyre
Paediatric Intensive Care Unit, Medico-Surgical Department of Paediatrics, Lausanne University Hospital (CHUV), Rue du Bugnon 46, 1011 Lausanne, Switzerland. Electronic address: david.longchamp@chuv.ch.
David
D
Longchamp
Paediatric Intensive Care Unit, Medico-Surgical Department of Paediatrics, Lausanne University Hospital (CHUV), Rue du Bugnon 46, 1011 Lausanne, Switzerland. Electronic address: marie-helene.perez@chuv.ch.
Marie-Hélène
MH
Perez
Institute for Social and Preventive Medicine (IUMSP), Biopôle 2, Route de la Corniche 10, 1010 Lausanne, Switzerland. Electronic address: patrick.taffe@chuv.ch.
Patrick
P
Taffé
Paediatric Intensive Care Unit, Medico-Surgical Department of Paediatrics, Lausanne University Hospital (CHUV), Rue du Bugnon 46, 1011 Lausanne, Switzerland. Electronic address: jacques.cotting@chuv.ch.
Jacques
J
Cotting
D002153:Calorimetry, Indirect; D002675:Child, Preschool; D016638:Critical Illness / Q000628:therapy*; D004044:Dietary Proteins / Q000008:administration & dosage* / Q000032:analysis; D002149:Energy Intake; D004734:Energy Metabolism; D004750:Enteral Nutrition; D005260:Female; D006801:Humans; D007223:Infant; D016014:Linear Models; D008137:Longitudinal Studies; D008297:Male; D009584:Nitrogen / Q000652:urine; D009751:Nutritional Requirements; D010288:Parenteral Nutrition; D011446:Prospective Studies; D012121:Respiration, Artificial
D004044:Dietary Proteins; D009584:Nitrogen
Child; Critical care; Energy expenditure; Indirect calorimetry; Infant; Nitrogen