Estimating ideal body mass in children.

An equation and nomogram to estimate ideal body mass (IBM) for establishing dosage regimens of certain drugs in children was derived from a large pediatric data base. The data were from more than 20,000 U.S. children (ages 1-17 years) included in two major surveys published by the National Center for Health Statistics. The IBM was defined as the 50th percentile weight for a given height (ht). The equation derived was IBM(kg) = 2.396e0.01863(ht), where height is in cm. The IBMs estimated from this equation were compared with estimates from three other methods, two of which were derived from an adult population. The adult methods were unsuitable for pediatric use. This equation and nomogram for estimating IBM in children should be useful in determining dosage regimens of aminoglycosides and other drugs for obese pediatric patients.