[Effects of propofol or sevoflurane on cerebral regional oxygen saturation (rSO2) during one-lung ventilation]

The present study was designed to evaluate the alteration of cerebral regional oxygen saturation (rSO2) associated with propofol or sevoflurane during one-lung ventilation (OLV).

Fifty patients scheduled for a lung lobectomy were randomly assigned to propofol or sevoflurane group. General anesthesia was maintained with propofol (target controlled infusion; 2-3 mcg x ml(-1)) in propofol group (n=25), and sevoflurane (end-tidal concentration 1-2%) in sevoflurane group (n=25), being adjusted to maintain BIS values between 40 and 60. BIS and rSO2 values were continuously monitored. Arterial blood gas analysis was performed as follows: during two-lung ventilation before OLV (baseline), during the first 120 minutes of OLV and at the end of OLV and surgery.

During OLV rSO2 was significantly lower than baseline in both groups. The values of rSO2 were not significantly different between the groups at each time. We could not find accurate correlation between rSO2 and other factors monitored.

We conclude OLV leads to the decrease of rSO2, but there is no difference in the alteration of rSO2 between propofol and sevoflurane group. To maintain adequate rSO2, we should consider together in combination with respiratory, circulatory or metabolic index and depth of anesthesia.