Effects of Desflurane Versus Propofol Anesthesia on Regional Cerebral Oxygenation during Spinal Surgery in the Prone Position

Context: Postural change during anaesthesia has a complex effect on systemic and cerebral circulations. Aim: The goal of the study was to evaluate the effects of desflurane and propofol on cerebral oxygenation during spinal surgery in the prone position. Settings and Design: A prospective randomized double-blinded trial. Methods and Materials: Fifty-two patients scheduled for spinal surgery were randomly allocated to propofol (n=25) and desflurane (n=27) groups. Anaesthetic agents were maintained to obtain a bispectral index of 50-55. SAP, DAP, HR, SPO2, ETCO2 and right and left rSO2 were assessed at seven-time points: supine position without oxygen administration (T1), supine position with oxygen administration (T2-baseline), intubation in the supine position (T3), just after prone positioning (T4), 10 minutes after prone positioning (T5), at the end of surgery in the prone position (T6) and at the end of anaesthesia in the supine position (T7). PCO2, PO2 and Hb partial were also recorded at T3 and T7. Results: Demographic data, pre-oxygenation hemodynamic variables and rSO2 were comparable between the groups. There was no significant difference between groups in SAP, DAP, HR, SPO2, and ETCO2 (p=0.095, p=0.061, p=0.357, p=0.088, p=0.328 respectively). PCO2, PO2 and Hb were not significant different between groups (p=0.542, p=0.394, p=0.768 respectively). rSO2 values were not significantly different between groups. In the propofol group, right rSO2 was significantly higher at T3 (p=0.017) and significantly lower at T5 (p=0,019) and at T6 (p=0,028) compared to baseline. Left rSO2 decreased significantly from baseline at T5 (p=0.026) in the propofol group. Left and right rSO2 in the desflurane group decreased significantly from baseline at T5 (p=0.0004 and p=0.0115). Conclusion: In the prone position, desflurane and propofol were associated with a significant decrease in rSO2 without differences between these anaesthetics.