Estimated basal metabolic rate and maintenance fluid volume in children: A proposal for a new equation

The basal metabolic rate (BMR) of children aged <2 years is proportional to their body weight (W; kg). However, no simple mathematical model for the estimation of BMR in children aged >= 2 years has been established. Based on Japanese studies on childhood BMR, conducted until the 1960s, we noted that childhood BMR (after infancy) is proportional to body weight to the power of 1/2 (W-1/2). Moreover, we confirmed that the two previously reported equations for calculating BMR (Schofield's equation and Oxford University's equations) are proportional to W-1/2. Based on these facts, we propose a new equation for the maintenance fluid volume for hospitalized children. Our equation (300 x W-1/2 mL/day) gives values almost equal to the maintenance fluid volume calculated by the most commonly used equation of Holliday and Segar in children aged 2-18 years. Our equation will be useful for pediatricians to calculate the maintenance fluid volume for children in daily clinical settings.