[The value of intraoperative monitoring of cerebral oxygen saturation on postoperative cognitive function in elderly patients undergoing cardiac surgery].

Objective

To investigate the effect of cerebral oxygen saturation (rSO2) on postoperative cognitive dysfunction (POCD) in elderly patients undergoing cardiac anesthesia.

Methods

Retrospective analysis was performed on 113 elderly patients (age 65-89) underwent cardiac surgery in Peking University International Hospital from June 2017 to December 2019, 67 male and 46 female patients were included. All operations were performed under general anesthesia, cardiopulmonary bypass, rSO2 and other relevant monitoring. Statistical analysis of the elderly patients with complications, cardiac surgery history, time of CPB, baseline value of rSO2 (rSO2 baseline), lowest intraoperative value of rSO2 (rSO2 min), time of operation, length of stay in CCU, length of hospital stay; Preoperative and postoperative NSE values; number of postoperative POCD and postoperative deaths were recorded. All data were obtained from the medical records system and anesthesia information system of Peking University International Hospital and risk factors related to POCD were analyzed by Logistic regression.

Results

POCD occurred in 19 patients (16.8%), and also, intraoperative rSO2 decreased by more than 30% over the baseline. The variance of rSO2 (rSO2 baseline-rSO2 min) in POCD group and non-POCD group was (18.0±2.7) and (6.6±2.3), the variance of NSE (NSE after surgery-NSE before surgery) was (31.3±9.7) and (9.5±3.0) μg/L, respectively. The differences were statistically significant (t=18.35, 17.70, all P<0.05). rSO2 variability was positively correlated with NSE variability (r=0.697, P<0.05). Logistic regression analysis showed that the variation degree of rSO2 [OR(95%CI)was 0.374(0.059-1.895)]、 patients combined with diabetes mellitus [OR(95%CI)was 0.493 (0.041-1.812), history of stroke [OR(95%CI)was 0.325 (0.084-0.917)] and atrial fibrillation [OR(95%CI)was 0.176 (0.091-0.943)] were the risk factors for POCD.

Conclusion

POCD can be predicted by monitoring the decline range of rSO2 intraoperatively. rSO2 is recommended as a routine monitoring item for elderly patients undergoing cardiac surgery.