[Monitoring system of cerebral blood flow and cerebral metabolism. Part II. Relationship between internal jugular O2 tention and cerebral blood flow (author's transl)].

Changes of PjO2 values of internal jugular vein were monitored in patients with various types of cerebrovascular disease. The significance of PjO2 monitoring was evaluated. 1) Control value of PjO2 in thirteen normal control cases was 36.7 +/- 1.9 mmHg (mean +/- SD). 2) Limit of brain hypoxia showing no neurological sign and symptom in patients with occlusive cerebrovascular disease was studied by the stepwise reduction of arterial blood pressure, using drip infusion of trymetaphan camsylate, under the careful monitoring of signs and symptoms and monitoring of PjO2 and EEG. Appearance of signs and symptoms of brain hypoxia were checked by yawning and EEG slowing. At the time of the appearance of brain hypoxia PjO2 was 28.6 +/- 3.2 mmHg. 3) CO2 reactivity of CBF was studied in patients with occlusive cerebrovascular disease. Relation between PaCO2 and PjO2 was as follows; PjO2 = 0.68 . PaCO2 + 7.55 4) Within 24 hours after the onset of stroke, ipsilateral PjO2 of the cases with disturbance of consciousness was lower than that of the cases without disturbance of consciousness, which might indicate the significant decrease of CBF in the former cases. During 3rd to 7th day after the onset the cases with disturbance of consciousness showed the significant elevation of PjO2, which might indicate the reduction of cerebral metabolism. 5) The elevation of ipsilateral PjO2 were well correlated to the degree of hemispheric brain swelling. 6) During general convulsion, high level of PjO2 values were observed. 7) PjO2 values were inversely correlated to the hemoglobin values after blood transfusion, which was mainly due to the decrease of CBF by high content of hemoglobin.