NOVA BIOMEDICAL Stat Profile PRIME - Calculated Parameters

B-7
Appendix B
Appendix B
B.2.2 Calculated Parameters
Calculated Bicarbonate Concentration [HCO
3
-
]
2
Bicarbonate Concentration (mmol/L) is calculated using the
Henderson-Hasselbalch equation:
[HCO
3
-
]
pH = pK + log –———— Equation 16
α(PCO
2
)
where pH and PCO
2
are measured.
pK = 6.091
α = 0.0307 = solubility coefcient of CO
2
in plasma at 37 °C
Rearranging Equation 16 gives:
Log
10
[HCO
3
-
] = pH + log
10
PCO
2
- 7.604
Equation 17
*The equations are from NCCLS standards
2
.
Total Carbon Dioxide Content (TCO
2
)*
TCO
2
(mmol/L) includes both dissolved carbon dioxide and
[HCO
3
-
] and is calculated as follows:
TCO
2
= [HCO
3
-
] + α(PCO
2
) Equation 18
where PCO
2
is measured and [HCO
3
-
] is calculated from
Equation 17.
* The equations are from Reference 2.