The origin of the 1 x 73-m2 body surface area normalization: problems and implications.

A historical review of the origins of body surface area (BSA) determination reveals a number of theoretical and methodological errors, as does the choice of 1 x 73 m(2) as the normal BSA for humans. BSA normalization is justifiable for some physiological variables, e.g. glomerular filtration rate and cardiac output, but not all. However, other normalization indices, in particular extracellular volume, offer theoretical and practical advantages compared with BSA. While the choice of the figure 1 x 73 m(2) is essentially arbitrary, and inapplicable to modern Western populations, its retention as a permanent physiological constant is recommended, in order to permit international and historical comparisons.