Quantitative relationships among plasma lactate, inorganic phosphorus, albumin, unmeasured anions and the anion gap in lactic acidosis
Quantitative relationships among plasma [Lactate], [Pi], [Albumin], unmeasured anions ([UA]) and the anion gap (AGK) in lactic acidosis (LA) are not well defined. A mathematical model featuring compensatory potassium and chloride shifts and respiratory changes in LA demonstrated: (1) AGK=[Lactate]+Z...
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Published in | Journal of critical care Vol. 44; pp. 101 - 110 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
United States
Elsevier Inc
01.04.2018
Elsevier Limited |
Subjects | |
Online Access | Get full text |
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Summary: | Quantitative relationships among plasma [Lactate], [Pi], [Albumin], unmeasured anions ([UA]) and the anion gap (AGK) in lactic acidosis (LA) are not well defined.
A mathematical model featuring compensatory potassium and chloride shifts and respiratory changes in LA demonstrated: (1) AGK=[Lactate]+Zp×[Pi]+2.4×[Albumin]+constant1+e, where Zp is a function of pH, and e reflects unmeasured anions and cations plus pH-related variations. Eq. (1) can be algebraically rearranged to incorporate the albumin-corrected anion gap, cAGK: (2) cAGK=[Lactate]+Zp×[Pi]+constant2+e. Eq. (1) was tested against 948 data sets from critically ill patients with [Lactate] 4.0mEq/L or greater. AGK and cAGK were evaluated against 12,341 data sets for their ability to detect [Lactate]>4.0mEq/L.
Analysis of Eq. (1) revealed r2=0.5950, p<0.001. cAGk>15mEq/L exhibited a sensitivity of 93.0% [95% CI: 91.3–94.5] in detecting [Lactate]>4.0mEq/L, whereas AGK>15mEq/L exhibited a sensitivity of only 70.4% [67.5–73.2]. Additionally, [Lactate]>4.0mEq/L and cAGK>20mEq/L were each strongly associated with intensive care unit mortality (χ2>200, p<0.0001 for each).
In LA, cAGK is more sensitive than AGK in predicting [Lactate]>4.0mEq/L. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0883-9441 1557-8615 |
DOI: | 10.1016/j.jcrc.2017.10.007 |