Testing a Novel Method for Measuring Sleeping Metabolic Rate in Neonates

Abstract

BACKGROUND: Sleeping metabolic rate (SMR) is used as a proxy for basal metabolic rate in infants, when measurement while awake is not practical. Measuring SMR via indirect calorimetry (IC) can be useful for assessing feeding adequacy especially in compromised neonates. Standard IC equipment, including a hood placed over the head, is not designed for the smallest of patients. Our aim was to determine whether a nonstandard smaller hood measures SMR in neonates similarly compared with a standard large hood. METHODS: SMR was measured in healthy neonates (controls) and those born with single-ventricle congenital heart disease (cases). Two measurements were performed: SMR using a standard large hood and SMR using a smaller hood. Time-to-steady state, minute ventilation (V E ), and fraction of exhaled carbon dioxide (F E CO 2 ; an indicator of data quality) were also measured. Primary outcome was SMR using both hoods. Results are stated as median (interquartile range). Spearman's correlations measured association between the small and large hoods. RESULTS: We studied 9 controls and 7 cases.

Daily energy expenditure through the human life course

“…These 6,421 measurements were used in this analysis. This dataset was augmented with published basal expenditure measurements for n=136 neonates and infants (31)(32)(33)(34)(35)(36) that included fat free mass and fat mass. Malnourished or preterm infants were excluded.…”