抄録
In mongrel dogs divided into two groups one is in experimental hypercapnea and another is in cessation of breathing. Cerebrospinal fluid PH (CSF-PH) is monitored continuously with new investigated PH-sensor with FET microelectrode, PO2 and lactate concentration in blood and CSF were also measured in the two groups. CSF-PH became acidosis but blood pressure, PO2 and lactate concentration in blood and CSF were almost constant in the group of experimental hypercapnea. On the other hand, blood pressure assended initially, and then descended subsequently in addition to CSF acidosis in the group of cessation of breathing. PO2 was decreased and lactate concentration wasincreased significantly in the experiments of cessation of breathing. In resuscitation after the cessation of breathing, all the three dogs for which resuscitation was resumed at PH 7.1 were recovered, three out of five dogs at PH 7.0 died and all other three dogs at PH 6.9 died. These experimental findings indicate that experimental hypercapnea causes only respiratory acidosis but the cessation of breathing causes the metabolic acidosis by brain anoxia in addition to the respiratory acidosis. Irreversible brain deterioration is caused by the development of the metabolic acidosis up to a certain level. The degree of the metabolic acidosis is more reliable parameter for the reversibility of coma than CSF-PH.
