EasyTBSA as a method for calculating total body surface area burned: a validation study

Current methods of burn estimation can lead to incorrect estimates of the total body surface area (TBSA) burned, especially among injured children. Inaccurate estimation of burn size can impact initial management, including unnecessary transfer to burn centres and fluid overload during resuscitation. To address these challenges, we developed a smartphone application (EasyTBSA) that calculates the TBSA of a burn using a body-part by body-part approach. The aims of this study were to assess the accuracy of the EasyTBSA application and compare its performance to three established methods of burn size estimation (Lund-Browder Chart, Rule of Nines and Rule of Palms).Twenty-four healthcare providers used each method to estimate burn sizes on moulaged manikins. The manikins represented different ages (infant, child and adult) with different TBSA burns (small <20%, medium 20%-49% and large >49%). We calculated the accuracy of each method as the difference between the user-estimated and actual TBSA. The true value of the complete body surface area of the manikins was obtained by three-dimensional scans. We used multivariable modelling to control for manikin size and method.Among all age groups and burn sizes, the EasyTBSA application had the greatest accuracy for burn size estimation (-0.01%, SD 3.59%) followed by the Rule of Palms (3.92%, SD 10.71%), the Lund-Browder Chart (4.42%, SD 5.52%) and the Rule of Nines (5.05%, SD 6.87%).The EasyTBSA application may improve the estimation of TBSA compared with existing methods.