Estimating Neonatal Oxygen Consumption from Heart Rate

Abstract

ABSTRACT The relationship between heart rate (HR) and oxygen consumption (V̇ o 2 ) has been investigated in a sample of 20 low‐risk, term neonates aged 14–48 hrs. Repeated, simultaneous measurements of HR and V̇ o 2 were performed on each neonate during each of three epochs ordered by increasing level of activity. A robust linear relationship was found between HR and V̇ o 2 , with an average correlation of.90. Substantial variation was observed across individuals in the slope of the HR‐V̇ o 2 regression line. This variation was curvilinearly related to ponderal index (PI), with low PI neonates having the shallowest and steepest slopes. These findings suggest that HR may provide a flexible, non‐restrictive means of estimating neonatal V̇ o 2 but that the impact of prenatal growth history and postnatal growth performance on the estimation of V̇ o 2 from HR merits further investigation.