An allometric model to estimate fluid requirements in children following burn injury.

Objectives: To evaluate the ability of an allometric 3/4 Power Model combined with the Galveston Formula (Galveston-3/4 PM Formula) to predict fluid resuscitation requirements in children suffering burn injuries in comparison with the frequently used Parkland Formula and Galveston Formula using the Du Bois formula for surface area estimation (Galveston-DB Formula).

Aim: To demonstrate that the Galveston-3/4 PM Formula is clinically equivalent to the Galveston-DB Formula for the estimation of fluid requirements in pediatric burn injury cases.

Background: Fluid resuscitation requirements differ in children suffering burn injuries when compared to adults. The Parkland Formula works well for normal weight adults but underestimates fluid requirements when indiscriminately applied to pediatric burn patients. The Galveston-DB Formula accounts for the change in body composition with age by using a body surface area (BSA) model but requires the measurement of height. The allometric model, using an exponent of 3/4, accounts for the dependence of a physiological variable on body mass without requiring height measurement and can be applied to estimate fluid requirements after burn injury in children.

Methods: Comparisons were performed between the hourly calculated fluid requirements for the first 8 h following 20%, 40%, and 60% BSA burns using the Parkland Formula, the Galveston-DB Formula and Galveston-3/4 PM Formula for children 2-23 kg.

Results: In children less than 23 kg, the fluid requirements predicted by the Galveston-3/4 PM Formula are well correlated with those predicted by the Galveston-DB Formula (R2 = 0.997, P < 0.0001) and are much better than of the predictions made with the Parkland Formula, especially for children <10 kg.

Conclusions: For the purposes of clinical estimation of fluid requirements, the Galveston-3/4 PM Formula is indistinguishable from the Galveston-DB Formula in children 23 kg or less.