Abstract
Objective
To demonstrate the practicability of a tri-axial chart for the graphical and quantitative monitoring of arterial pH, arterial carbon dioxide partial pressure (PaCO2) and actual arterial bicarbonate-ion concentration (a[HCO −3 ]) in intensive care patients.
Design
Case report.
Setting
A general intensive care unit (ICU).
Methods
Using a standard mathematical transformation, a data set of pH, log PaCO2 and log a[HCO −3 ] values can be transformed in such a way that a graphical display of all three variables is possible while being faithful to their linear relationship. Remarkably, the graphical display closely resembles the tri-axial chart that Hastings and Steinhaus described in 1931 for studying displacements of the acid-base balance. Two new monitoring parameters based on the chart and the transformation are described. One monitors the abnormality of the acid-base status while the other monitors the rate of acid-base changes.
Conclusions
With the tri-axial acid-base chart, the complete acid-base status can be faithfully monitored. Moreover, the proposed monitoring parameters provide extra information about the arterial acid-base status that, otherwise, would remain hidden.
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Hekking, M., Ulenkate, H.J.L.M., Speelberg, B. et al. A re-appraisal of the tri-axial chart for monitoring arterial acid-base values. Intensive Care Med 24, 977–980 (1998). https://doi.org/10.1007/s001340050699
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DOI: https://doi.org/10.1007/s001340050699