外傷性クモ膜下出血の脳循環・代謝に及ぼす影響と予後―TCDを主体としたモニタリングの解析から―

抄録

Chronological changes of cerebral hemodynamics and cerebral oxygen metabolism in patients with head injuries associated with TSAH were analyzed by TCD and SjO₂to evaluate disturbances accompanying traumatic vasospasm and the final outcome.
The subjects were 44 head injury patients with Glasgow Coma Scale (GCS) scores of 3-15 (mean, 7) . Mean velocity (Vm) and pulsatility index (PI) in the middle cerebral artery were monitored continuously for 3 weeks after injury. The subjects were classified into Group S (19 cases) with and Group N (25 cases) without TSAH based on the initial CT findings, they were subdivided into two groups of initial GCS≤8 and 9≤. Sequential changes in the TCD findings in the periods 0-2, 3-7, 8-14, 15-21 and 22- days after injury were compared. In cases with GCS≤8, there was a weak correlation between the patient's outcome one and six months after injury and increased Vm (≥100 cm/s) on the 7th day after injury.
Comparison between Group S and N showed: 1) Significant Vm increase and lower PI increase in group S compaired with group N (GCS≤8 cases) . 2) In both groups, Vm tended to increase and PI to decrease in correlation with TSAH (Fisher's classification) .3) Craniotomy did not influence Vm or PI in either group. 4) SjO₂increase (>80%) tended to be correlated with increase in Vm (≥100 cm/s) cases. 5) Angiography demonstrated vasospasm and SPELT hypoperfusion in two of three cases of increased Vm (≥100 cm/s), but did not show development to cerebral infarction. 6) Poor outcome was predominant in cases with increased Vm in Group S.
Increases in Vm and PI in patients with TSAH were probably related to localized ischemia and increased cerebrovascular resistance due to vasospasm after severe head injury, but global hyperemia based on oxygen metabolism indicated a poor outcome. Therefore, it is necessary to take account of abnormal hyperemia associated with TSAH after severe head injury.