Effect of acetazolamide on regional cerebral oxygen saturation and regional cerebral blood flow.

Abstract

To verify whether the monitoring of regional cerebral oxygen saturation (rSO2) with transcranial near-infrared spectroscopy would successfully reflect changes in intracranial hemodynamics but not changes in extracranial compartment, we measured rSO2 and regional cerebral blood flow (rCBF) simultaneously in seven patients with cerebral ischemia and five normal volunteers before and after acetazolamide administration. The baseline values of rSO2 and rCBF were 64.2 +/- 5.6% and 53.9 +/- 11.1 mL/100 g per minute, respectively. rCBF increased by 44.4 +/- 23.3% and rSO2 significantly increased to 69.6 +/- 5.6% after acetazolamide administration. Bilateral simultaneous measurement of rSO2 indicated a tendency that the larger the delta rSO2, the greater the delta%rCBF. The relationship between rSO2 level and rCBF value fit significantly on the theoretical curve calculated from Fick's equation. It is suggested that monitoring of rSO2 with INVOS-3100 could be a useful indicator in the evaluation of intracranial hemodynamic changes.