 rate chang carbon dioxid tension arteri blood jugular venou blood cistern cerebrospin fluid carbon dioxid administr 1 rate chang arteri blood cistern measur 5 percent administr anaesthet patient undergo routin air encephalographi ventil maintain constant procedur respir three experi rate chang jugular venou blood measur 2 rise vari 25 7 14 8 mm hg final sampl blood 20-25 min start administr experi time rise 65 9 maximum rang 68 1-61 6 percent rise remain three experi final sampl 15 min rise 53 2 39 4 38 1 percent arteri chang 3 increas 57 5 76 2 76 1 percent arteri blood chang smaller jugular venou blood three experi experi final sampl 15 min start administr increas 68 5 percent 50 percent jugular venou blood experi final sampl 20 min increas 89 percent rise 4 delai start administr rise jugular venou blood delai 1 min jugular venou blood vari 1 6 4 2 min 2 3 5 rise blood exponenti rise experi consist fast compon time constant vari 0 2 0 9 min 0 5 slow compon time constant vari 6 7 14 7 11 6 rise p consist compon time constant chang jugular venou blood 2 1 3 8 4 3 min whilst vari 6 7 14 7 11 6 6 probabl 40 percent increas ventil administr stimul area antero-later surfac medulla sensit chang ph mitchel al 1963 area superfici ventil chang overli predict experi rise administr 30 min complet explain slow rise ventil breath compar rate rise arteri jugular venou 