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

Area of Science:

• Physiology
• Medical Informatics

Background:

• Historical review of body surface area (BSA) determination methods.
• Identifies theoretical and methodological errors in BSA calculation and the standard 1.73 m² value.
• Notes the arbitrary nature and inapplicability of the 1.73 m² standard to modern populations.

Purpose of the Study:

• To critically evaluate the origins and application of body surface area (BSA) normalization in physiology.
• To compare BSA with alternative normalization indices, such as extracellular volume.
• To provide recommendations on the continued use of BSA standards.

Main Methods:

• Historical literature review on BSA determination.
• Analysis of theoretical and methodological aspects of BSA normalization.
• Comparison of BSA with extracellular volume as a normalization index.

Main Results:

• BSA determination and the 1.73 m² standard have significant theoretical and methodological flaws.
• BSA normalization is appropriate for some physiological variables (e.g., glomerular filtration rate, cardiac output) but not all.
• Extracellular volume presents theoretical and practical advantages over BSA for normalization.

Conclusions:

• The standard 1.73 m² for BSA is arbitrary and outdated for current populations.
• Despite its limitations, retaining the 1.73 m² BSA standard is recommended for international and historical comparability.
• Exploration of alternative normalization indices like extracellular volume is encouraged for specific physiological applications.