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Mixing bicarbonates: dilution acidosis from first principles

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Fig. 1


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    Take for instance the highest point in the curve for pCO2 = 100 mmHg. Assuming [H+] is additive (and hence for equal pCO2, [HCO3 ] is also additive), a [H+] of 6.070848e-07 would result instead of 1.517582e-07, and using this [H+] a new combined SID of 0.01193681 Eq/l would result, but we know it is 0.035 Eq/l, when mixing equal volumes of two fluids with SID 0.01 and 0.06 Eq/l.


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    Doberer D, Funk G-C, Kirchner K, Schneeweiss B (2009) A critique of Stewart’s approach: the chemical mechanism of dilutional acidosis. Intensive Care Med. doi: 10.1007/s00134-009-1528-y, published online 17 June 2009

  2. 2.

    Frassetto LA, Morris RC, Sebastian A (2007) Dietary sodium chloride intake independently predicts the degree of hyperchloremic metabolic acidosis in healthy humans consuming a net acid-producing diet. Am J Physiol 293:F521–F525

  3. 3.

    R Development Core Team (2008) R: a language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. ISBN 3-900051-07-0. http://www.R-project.org

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P. D. Watson is thanked for the AcidBasics II.

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Correspondence to Troels Ring.

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An author’s reply to this comment is available at: doi:10.1007/s00134-009-1671-5.

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Ring, T. Mixing bicarbonates: dilution acidosis from first principles. Intensive Care Med 35, 2183–2184 (2009). https://doi.org/10.1007/s00134-009-1668-0

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  • Open System
  • Bicarbonate
  • HCO3
  • Total Concentration
  • Classical Model