Regional cerebral oxygen saturation during induction of general anesthesia in the elderly

Introduction: Hypotension caused by induction of general anesthesia, if associated to a reduction in cerebral blood flow, could cause a potentially harmful decrease in cerebral oxygenation. Aims: Aim of the present study was to evaluate the effects of general anesthesia induction on regional cerebral oxygen saturation (rSO2) in patients aged 75 and more, undergoing elective non-cardiac surgery. Methods: In 22 patients aged 79\ub12 years general anesthesia was induced with propofol (2.0\ub10.5 mg/kg). Non-invasive mean arterial blood pressure (MAP), rSO2 (SICO, Covidien, USA) and bispectral index (BIS, Covidien, USA) were continuously measured. A mean preinduction value was calculated for each variable and compared with one-way ANOVA to post-induction values, averaged every 5 minutes. Results: Anesthesia induction caused a significant reduction in MAP and BIS (p<0.05 oneway ANOVA, Figure 1), while regional cerebral oxygen saturation transiently increased (p