Background:
This randomized clinical trial determined the effects of electroencephalographic burst suppression on cerebral oxygen metabolism and postoperative cognitive function in elderly surgical patients.
Methods:
The patients were placed into burst suppression (BS) and non-burst suppression (NBS) groups. All patients were under bispectral index monitoring of an etomidate target-controlled infusion for anesthesia induction and intraoperative combination sevoflurane and remifentanil for anesthesia maintenance. The cerebral oxygen extraction ratio (CERO
2
), jugular bulb venous saturation (SjvO
2
), and difference in arteriovenous oxygen (Da-jvO
2
) were measured at
T
0,
T
1, and
T
2. One day before surgery, and 1, 3, and 7 days after surgery, postoperative cognitive dysfunction was assessed using the mini-mental state examination (MMSE).
Results:
Compared with
T
0, the Da-jvO
2
and CERO
2
values were decreased, and SjvO
2
was increased in the 2 groups at
T
1 and
T
2 (
P
< .05). There was no statistical difference in the SjvO
2
, Da-jvO
2
, and CERO
2
values between
T
1 and
T
2. Compared with the NBS group, the SjvO
2
value increased, and the Da-jvO
2
and CERO
2
values decreased at
T
1 and
T
2 in the BS group (
P
< .05). The MMSE scores on the 1st and 3rd days postoperatively were significantly lower in the 2 groups compared to the preoperative MMSE scores (
P
< .05). The MMSE scores of the NBS group were higher than the BS group on the 1st and 3rd days postoperatively (
P
< .05).
Conclusion:
In elderly patients undergoing surgery, intraoperative BS significantly reduced cerebral oxygen metabolism, which temporarily affected postoperative neurocognitive function.