Evaluation and Optimization of the Wallace Rule of Nines for the Estimation of Total Body Surface Area in Obese and Nonobese Populations

Abstract

BackgroundCurrently, the Wallace Rule of Nines is the most widely used method to measure total body surface area (TBSA) in burned patients due to its practicality and speed in its application; however, it often provides inaccurate estimations in obese patients, affecting the fluid resuscitation process. ObjectiveIn this study, we aimed to modify and optimize the Rule of Nines’ values for its application in these patients. MethodsWe compared the estimations of the TBSA established by the Wallace Rule of Nines against the measurements of the three-dimensional (3D) software Skanect - Meshmixer 3.5Ⓡ in participants without different obesity grades. Based on our results, we generate an optimized guideline for the evaluation of TBSA in normal body mass index (BMI) and obese patients. ResultsIn our study, 32 participants were recruited with a mean age of 28.5 ± 3.3 years. In the general population, we observed a poor correlation between the Wallace Rule of Nines and the 3D method measures in all body regions (e.g., Anterior Trunk: 18.0 vs. 16.61 ± 2.11, p = 0.0008) except the anterior arm. Interestingly, these differences narrowed in the Trunk and Leg regions as the participants' BMI increased (e.g., Anterior Trunk in Obesity Grade II patients: 18.0 vs. 18.66 ± 1.69, p = 0.3089). ConclusionsWe found important differences in TBSA determination using the 3D Skanect-MeshmixerⓇ software compared with the Wallace Rule of Nines. Therefore, we generated a modified and optimized Wallace Rule of Nines estimations based on BMI. Future studies are needed to assess the safety and efficacy of this optimized table.