title: Misapplications of commonly used kidney equations: renal physiology in practice.
abstract: Equations for estimating GFR, quantifying urinary protein excretion, and assessing renal sodium handling are widely used in routine nephrology and general medical and surgical practice. If these equations are applied in circumstances inconsistent with the clinical situations for or extrapolated beyond the limits in which they were validated, clinicians can come to erroneous conclusions, which could be detrimental for patient care. This review uses clinical vignettes to demonstrate some of the common pitfalls that clinicians may encounter in the use of these equations and considers the physiologic principles underlying their use. Equations for assessing aspects of renal function should only be used in specific clinical situations, if the underlying assumptions regarding their calculations and values are satisfied.
authors.affiliation: Department of Medicine, Division of Renal Diseases and Hypertension, George Washington University Medical Center, Washington, DC 20037, USA.
authors.forename: Mai T
authors.initials: MT
authors.lastname: Nguyen
authors.forename: Sharon E
authors.initials: SE
authors.lastname: Maynard
authors.forename: Paul L
authors.initials: PL
authors.lastname: Kimmel
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007668:Kidney / Q000503:physiopathology*; D007674:Kidney Diseases / Q000175:diagnosis* / Q000503:physiopathology; D007677:Kidney Function Tests / Q000379:methods; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D011237:Predictive Value of Tests; D011247:Pregnancy; D011248:Pregnancy Complications / Q000175:diagnosis / Q000503:physiopathology; D011507:Proteinuria / Q000175:diagnosis / Q000503:physiopathology; D011934:Reagent Strips; D015203:Reproducibility of Results; D012964:Sodium / Q000378:metabolism; D016482:Urinalysis
chemical_list: D011934:Reagent Strips; D012964:Sodium