Estimation of body surface area of extremely obese human subjects

Abstract

The body surface areas of one normal and four extremely obese human subjects have been estimated by three methods: a) direct measurement by a method similar to that which Du Bois described; b) calculation from the Du Bois height-weight formula; and c) calculation from the Du Bois linear formula. The values for the total body surface area of the obese subjects calculated from the height-weight formula varied up to 11% below those that were directly measured. The values for the total body surface area obtained with the linear formula ranged between 13% and 20% above the direct measurements, this being almost entirely due to discrepancies in the trunk and in the thigh estimations. It has been concluded that estimation of the body surface area oxf extremely obese subjects by the Du Bois height-weight formula is satisfactory when considered in relation to the accuracy of the physiologic measurements with which it is generally used. Because of the unusual body form the Du Bois linear formula has been found unsatisfactory for this group. Submitted on March 1, 1960

Obesity and screening PSA levels among men undergoing an annual physical exam

“…Since gold standard measures of human body surface area are difficult to acquire, the formulas have not been rigorously compared to each other for relative criterion validity [21]. A small study that directly measured body surface area found that the Dubois formula performed well in the obese [29]. It is not entirely surprising that the dilution model produces predicted screening PSA values that are similar to the observed PSA values for body size categories; both estimated surface area and body mass index are functions of height and weight.…”

The origin of the 1·73‐m2 body surface area normalization: problems and implications

“…Surprisingly, the derived formula works well for normal adults, but breaks down when applied to children. Tucker & Alexander (1960) attempted to assess its relevance for extremely obese patients (>100 kg), but experienced considerable difficulty: ‘it was difficult for the four obese people to stand up for the time required for the entire taping process’; it was decided to use ‘the measurement in which the tape followed all the folds of the skin as opposed to a straight‐line measurement between two points’; ‘the exact location of the superior border of the greater trochanter was difficult to determine’, etc. (Fig.…”

“…the more it is magnified, the more details become apparent, and the greater the total surface area becomes, virtually ad infinitum . Thus, BSA is essentially just as indefinable as the length of the British coastline (Slone, 1993), and the figure of 1·73 represents an arbitrary choice of magnification. Attempts to measure surface area in severely obese individuals have proved to be both difficult and inaccurate (Tucker & Alexander, 1960). The use of any index to normalize physiological parameter requires first, that the parameter is a statistically significant linear function of the index, and secondly, that the intercept is not significantly different from zero.…”

BurnCalc assessment study of computer-aided individual three-dimensional burn area calculation

“…The Rule-of-Nines overestimates % TBSA, especially in persons with a high body mass index (BMI) [7]. BMI has a great influence on the BSA [8]. Previous studies have found that the actual palm surface area (PSA) is 0.76–0.78%, indicating an overestimation of 10–20% by the Rule-of-Palms technique [9-11].…”