Changes of Gas Values in the CSF by Continuous Controlled Hyperventilation

Keimyung Medical Journal 1987;6(2):373-378.

지속적 과환기에 따른 뇌척수액과 혈액가스치의 변화

전재규; 김진모

Abstract

Acid-base balance in CSF have been reported by a number of groups during past 20 years. CSF contained only negligible concentration of buffer anion other than HC03. Acid-base balance in the CSF depend mainly on arterial PC02 because arterial C02 diffuses easily into the blood brain barrier to form H2C03 in CSF. This study was undertaken to observe the changes of PH; PC02; base excess and actual HC03 values in CSF in the controlled hyperventilation. The changes in pH and actual HCOa; Base Excess in CSF of anesthetized; non-curarized 7 dogs during continous controlled hyperventilation were compared with those changes when the blood acid-base parameters were kept at normal level. Both groups were mechanically ventilated to maintain a constant PaC02 20 torr. The PH; PC02; actuairHCOsJ; and Base Excess in cisternal CSF and arterial blood were determined at normal condition as a control group shortly after induction of controlled hyperventilation thereafter; were measured at 0.5; 1.0; 1.5; 3.5; 5.5 and 7.5 hours. The results were as follows: 1) The pH of CSF in the controlled group was significantly lower than that of arterial blood and the Pcsf C02 was 10 torr higher than PaC02. 2) The standardrHCOsJand BE seemed to be compensating after continous hyperventilation of 3.5 hours and reached to the values of the controlled group. 3) The Pcsf C02 decreased rapidly during hyperventilation and then; was maintained in a parallel distance with PaC02.