Choice of the best equation for plasma osmolality calculation: Comparison of fourteen formulae

Clinical Biochemistry
José L Martín-CalderónFernando Solano

Abstract

Many different equations have been previously described to estimate plasma osmolality. The aim of this study is to compare 14 of these equations, in order to determine which results agree best with measured osmolality. Our aim is to elucidate which is the most accurate equation for osmolality calculation among the fourteen that were previously described. We measured osmolality by the freezing point depression method, and glucose, urea, sodium, potassium, calcium and magnesium concentrations with Unicell DXC 800 analyzer. Goodness-of-fit rates were calculated using the Passing-Bablok regression model and the t-paired sample test. In addition, we used survival curves in order to find the percentage of cases in which the difference between measured and calculated osmolality was under 10 mOsm/kg. Data were plotted using the Bland-Altman graphical approach. The equation that provides the best fit between measured and calculated osmolality is 1.86(Na+K)+1.15(Glu/18)+(Urea/6)+14, followed by 2Na+1.15(Glu/18)+(Urea/6). According to our results, the Dorwart-Chalmer's equation should not be used for osmolality calculations. The equation 1.86(Na+K)+1.15(Glu/18)+(Urea/6)+14 is the most accurate. The widespread use of the equation 2(Na+K)+(...Continue Reading

References

Nov 1, 1983·Journal of Clinical Chemistry and Clinical Biochemistry. Zeitschrift Für Klinische Chemie Und Klinische Biochemie·H Passing, Bablok
Apr 1, 1983·Annals of Internal Medicine·A H Sklar, S L Linas
Jul 9, 2004·Intensive Care Medicine·Knut Erik HovdaDag Jacobsen
Jul 12, 2005·Clinical Chemistry and Laboratory Medicine : CCLM·Mehdi Rasouli, Kiarash Rezaei Kalantari
Jul 1, 2009·Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine·Jennifer S BoyleChristopher P Holstege

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Citations

Jun 28, 2016·Clinical Biochemistry·Mehdi Rasouli
Mar 18, 2017·Postgraduate Medicine·George LiamisMoses S Elisaf
May 16, 2017·Annals of Clinical Biochemistry·Urs WilgenJacobus Pj Ungerer
Sep 30, 2018·The Journal of Physiology·Shaelynn M ZouboulesTrevor A Day
Jul 10, 2019·Acta Anaesthesiologica Scandinavica·Magnus LjunggrenSnejana Hyllén
Jul 12, 2017·Seminars in Dialysis·Anika T Singh, Finnian R Mc Causland
Feb 18, 2020·Peritoneal Dialysis International : Journal of the International Society for Peritoneal Dialysis·Kornchanok Vareesangthip, Andrew Davenport
Jan 27, 2020·Clinical and Experimental Nephrology·Ezgi KarI Özkan Alataş
Aug 22, 2017·Journal of the Endocrine Society·Elena M KaftanovskayaAlexander I Agoulnik
Apr 21, 2021·BMJ Case Reports·Rasmus Søgaard HansenLars Folkestad

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