Abstract
Preoperative studies of cerebral blood flow (CBF) and oxygen metabolism were performed in 42 patients with ruptured intracranial aneurysms in the acute stage within 72 hours after subarachnoid hemorrhage.
We evaluated correlations between CBF, oxygen metabolism and preoperative neurological conditions (Hunt and Hess' classification, grade I, II, III)
Measurement of CBF was made by 133Xe inhalation technique (ISI value), and mean CBF was obtained from average value of 7 probes on para-Rolandic area.
Oxygen metabolism (cerebral oxygen utilization; CMRO2, cerebral oxygen delivery; D-O2, oxygen extraction fraction; OEF) was calculated based on oxygen content of arterial and jugular blood, and CBF.
The results were as follows.
1) CBF: grade I 46.9±4.0, grade II 36.8±5.0, grade III 25.3±5.0, respectively. The reduction of CBF even in the best clinical condition (grade I & II), but most decrease in CBF was found in grade III patients. Each groups had significant differences in CBF value (P<0.001).
2) CMRO2: grade I 2.82±0.26, grade II 2.35±0.37, grade III 1.68±0.28, respectively. Significant difference was found between grade I & II (P<0.01) and grade II & III (P<0.001).
3) D-O2: grade I 7.32±0.89, grade II 5.91±0.80, grade III 3.87±0.74, respectively. There were significant differences between grade I & II, and grade II & III (P<0.001).
4) OEF: grade I 0.39±0.06, grade II 0.40±0.07, grade III 0.44±0.07, respectively. Significant differences were not found, but OEF values were increasing as grades were worsening.
These results indicated that preoperative grade was worse, impairment of CBF and oxygen metabolism were remarkable, and removal of factors deteriorating intracranial environment was thought to be essential.
