Comparison of Normal Gas Values in the CSF, Arterial and Venous Blood / 대한마취과학회지

ABSTRACT

The cerebrospinal fluid(CSF) contains only negligible concentrations of buffer anions other than HCO3- because there is no hemoglobin buffer syatem. CSF gas values have been reported and it has been shown that arterial CO2 diffuses easily into the blood brain barrier to form H2CO3 in the CSF. No study for normal valuea of CSF gaaes in Koreans has been reported. The study was attempted to obtain the normal. values of CSF gases and also to compare values of gases in the three different components, j,e. CSF, arterial and venous blood. Relatively healthy patients with no respiratory or systemic disturbances who were sch-eduled for simple operations have been studied. Prior to the induction of aneathesia, Ium-bar tapping was Performed at a level of L3-4 using a 22 gauge needle and CSF samples-were obtained. Then the racial samples were taken. The subclavian vein was cannulated with a 20 gauge catheter and venous b1ood samples were obtained. All the gas values were-compared as shown in the tab1es and figures. The results obtained were as fallows PCSF O2 was 76.5+/-8.6 torr and PcsF CO2 was 44.9+/-3.6 torr. Both data in the CSF fall in the middle of the arterial and venous valses. The pH of the CSF was 7.329+/-0.017, HCO3- was 23.6+/-1.8 mEq/L and the base excess was -2.2+/-1.5. All the above data are the lowest among the three components, The pH of the CSF is more acid than arterial or venous blood and that pH regulation of the CSF is seemed to be limited because there is no compensatory hemoglobin buffer in the CSF. The finding of the CSF gas values obtained in this study is introduced as a normal data for further physiological study of the CSF.