Acid-base Constants And Temperature Coefficients For Cerebrospinal Fluid
The solubility of CO2 in human cerebrospinal fluid (CSF) is 0.0312 mmole/liter·mm Hg at 38 C. The first dissociation constant (pK1') of carbonic acid at 38 C is 6.130 at pH 7.30 and varies inversely with pH and temperature. At pH 7.30 DeltapK1'/ DeltapH is -0.050 and DeltapK1'/DeltaT is-0.0029 U/°C. pH of CSF varies inversely with temperature over the range of pH from 6.9 to 7.7. DeltapH/DeltaT is -0.0037 U/°C. The temperature correction for CSF Pco2 is expressed Pco2T1/Pco2T2 = 10 f(T1–T2) At pH 7.30, f is 0.0110. The effect of varying Pco2 on pH in vitro at 38°C, expressed as Delta log Pco2/DeltapH, is 1.063 ± 0.022.
first dissociation constant; CO2 solubility; CSF buffering
Submitted on February 20, 1964