J. Depeyre

Performance of Predictive Equations Specifically Developed to Estimate Resting Energy Expenditure in Ventilated Critically Ill Children

Objective To determine, based on indirect calorimetry measurements, the biases of predictive equations specifically developed recently for estimating resting energy expenditure (REE) in ventilated critically ill children, or developed for healthy populations but used in critically ill children. Study design A secondary analysis study was performed using our data on REE measured in a previous prospective study on protein and energy needs in pediatric intensive care unit. We included 75 ventilated critically ill children (median age, 21 months) in whom 407 indirect calorimetry measurements were performed. Fifteen predictive equations were used to estimate REE: the equations of White, Meyer, Mehta, Schofield, Henry, the World Health Organization, Fleisch, and Harris‐Benedict and the tables of Talbot. Their differential and proportional biases (with 95% CIs) were computed and the bias plotted in graphs. The Bland‐Altman method was also used. Results Most equations underestimated and overestimated REE between 200 and 1000 kcal/day. The equations of Mehta, Schofield, and Henry and the tables of Talbot had a bias ≤10%, but the 95% CI was large and contained values by far beyond ±10% for low REE values. Other specific equations for critically ill children had even wider biases. Conclusions In ventilated critically ill children, none of the predictive equations tested met the performance criteria for the entire range of REE between 200 and 1000 kcal/day. Even the equations with the smallest bias may entail a risk of underfeeding or overfeeding, especially in the youngest children. Indirect calorimetry measurement must be preferred.

Estimation of Resting Energy Expenditure Using Predictive Equations in Critically Ill Children: Results of a Systematic Review.

Provision of adequate energy intake to critically ill children is associated with improved prognosis, but resting energy expenditure (REE) is rarely determined by indirect calorimetry (IC) due to practical constraints. Some studies have tested the validity of various predictive equations that are routinely used for this purpose, but no systematic evaluation has been made. Therefore, we performed a systematic review of the literature to assess predictive equations of REE in critically ill children. We systematically searched the literature for eligible studies, and then we extracted data and assigned a quality grade to each article according to guidelines of the Academy of Nutrition and Dietetics. Accuracy was defined as the percentage of predicted REE values to fall within ±10% or ±15% of the measured energy expenditure (MEE) values, computed based on individual participant data. Of the 993 identified studies, 22 studies testing 21 equations using 2326 IC measurements in 1102 children were included in this review. Only 6 equations were evaluated by at least 3 studies in critically ill children. No equation predicted REE within ±10% of MEE in >50% of observations. The Harris-Benedict equation overestimated REE in two-thirds of patients, whereas the Schofield equations and Talbot tables predicted REE within ±15% of MEE in approximately 50% of observations. In summary, the Schofield equations and Talbot tables were the least inaccurate of the predictive equations. We conclude that a new validated indirect calorimeter is urgently needed in the critically ill pediatric population.).

Miniaturized capnometer sensor based on the ionization quenching effect

A novel carbon dioxide sensor for biomedical use exploits the effect of quenching of oxygen ionization due to the presence of CO2. During the development of an optical emission spectroscopy gas analyzer, it was noted that the presence of carbon dioxide was decreasing the whole optical emission due to oxygen also present in the gas mixture. This effect can be used for measuring carbon dioxide in expired breath. A prototype was built for assessing the feasibility of the concept, with good results. The system can be run on very low power and can be effectively miniaturized.

P312: La balance protéino-énergétique est-elle mieux équilibrée chez les jeunes enfants sévèrement malades que chez les plus âgés ?

Introduction et but de l’etude Les enfants severement malades hospitalises en soins intensifs de pediatrie sont a risque de denutrition. Une prise en charge nutritionnelle optimale est necessaire car elle influence leur issue clinique. Peu d’etudes ont documente la comparaison des apports avec les besoins nutritionnels aupres de cette population, et particulierement pour les enfants de plus de 2 ans. Le but de l’etude est de determiner si la balance proteino-energetique est mieux equilibree chez les jeunes enfants severement malades que chez les plus âges. Materiel et methodes Une etude d’observation de type longitudinale avec une recolte de donnees retrospective a ete menee dans une unite de soins intensifs de pediatrie. Les enfants severement malades avec une duree de sejour de ≥ 48 heures et ne recevant pas d’alimentation per os a l’admission ont ete inclus. Les apports quotidiens en energie et proteines ont ete comptabilises du jour de l’admission jusqu’au jour de l’introduction de l’alimentation orale, du 10 e jour d’hospitalisation, de la sortie ou du deces du patient. Les besoins energetiques et proteiques ont ete calcules, respectivement, avec l’equation de Schofield et les recommandations de la Societe Americaine pour la Nutrition Parenterale et Enterale. Les apports ont ete compares quotidiennement aux besoins. Les analyses statistiques ont ete stratifiees par tranches d’âge : 0–2 ans, 2–12 ans, 12–18 ans. Resultats et Analyse statistique Un total de 206 enfants severement malades, soit 110 garcons et 96 filles, avec un âge median de 1,4 ans [ecart interquartile EI : 2,8–4] ont ete inclus et 1 155 jours ont ete etudies. Un support nutritionnel etait present chez 195 patients, essentiellement sous forme de nutrition enterale exclusive (95 %). Sur la periode etudiee, la couverture mediane des apports energetiques etait de 87 % [EI : 66–131] chez les 0–2 ans, de 51 % [EI : 3–69] chez les 2–12 ans et de 21 % [EI : 14–33] chez les 12–18 ans. Le groupe des 0–2 ans couvrait ses besoins energetiques a J2 alors que les 2–12 ans et les 12–18 ans ne couvraient pas leurs besoins energetiques durant l’etude. Concernant les proteines, la couverture mediane des apports etait de 51 % [EI : 35–76] chez les 0–2 ans, de 38 % [EIQ : 14–65] chez les 2–12 ans et de 14 % [EI : 0–20] chez les 12–18 ans. Le groupe des 0–2 ans et 12–18 ans ne couvraient pas leurs besoins proteiques durant l’etude et le groupe des 2–12 ans les couvrait a J10. Conclusion Ces resultats obtenus en soins intensifs de pediatrie montrent que plus les patients sont âges, plus ils ont de la difficulte a couvrir leurs besoins nutritionnels. En comparaison a la couverture des besoins energetiques, la couverture des besoins proteiques est plus difficilement atteignable. Les enfants des l’âge de 2 ans, particulierement les adolescents, doivent retenir l’attention du personnel medical et soignant, car ils sont a risque de malnutrition.