Dysautoregulation in patients with ruptured aneurysms: cerebral blood flow measurements obtained during surgery by a temperature-controlled thermoelectrical method.

We used a temperature-controlled thermoelectrical method, induced hypotension, and CO2 inhalation to obtain cerebral blood flow (CBF) measurements during surgery for investigation of the state of brain vasoreactivity in subarachnoid hemorrhage patients. The study included 11 patients who underwent 12 operations for ruptured intracranial aneurysms. The CBF data were analyzed to investigate the neurological state, presence or nonpresence of vasospasm, timing of the operation, and outcome of each patient. Autoregulation disturbance, in terms of reaction to hypotension, was consistently seen in patients in poor neurological states, and this disturbance was correlated with poor outcome. This simple monitoring system, used during emergency operations for ruptured aneurysm, was useful in predicting outcome.