Intraoperative application of regional cerebral oxygen saturation monitoring for geriatric patients in China: a survey

Abstract

Background: Regional cerebral oxygen saturation (rSO₂) monitoring is a real-time and non-invasive technique for estimating the balance of regional cerebral oxygen supply and consumption. Despite the growing popularity of this monitoring technique, data regarding outcome benefits remain sparse and contradictory. This study was conducted to explore the popularity and understanding of cerebral oxygen saturation monitoring during anesthesia in geriatric patients.

Methods: An online self-report questionnaire was distributed in March 2021 to various hospitals in China for dissemination to anesthesiologists. Questions surveyed cerebral oximetry equipment and utilization, demographics, and clinical practice of participants.

Results: In total, 447 anesthesiologists responded. Of these, 301 (67.3%) respondents reported that their hospitals were equipped with cerebral oximetry, which 274 anesthesiologists use during anesthesia. A high percentage of anesthesiologists chose to monitor rSO₂ during cardiac surgery (77.4%, n = 212) and neurosurgery (40.5%, n = 111). Most anesthesiologists agreed that a 30% reduction from the rSO₂ baseline requires intervention to avoid cerebral ischemia, mainly via elevating arterial pressure and fraction of inspired oxygen (FiO₂). Of those without cerebral oximetry, 138 of 146 (94.5%) anesthesiologists were willing to monitor rSO₂. In addition, 291 respondents believed that cerebral oxygen monitoring would help prevent postoperative cognitive dysfunction.

Conclusion: Our survey indicated that the prevalence of cerebral oximetry remains relatively low, while almost all anesthesiologists expressed their willingness to use rSO₂ monitoring in geriatric anesthesia. Heterogeneity in clinical practice was identified, indicating relevant knowledge gaps that should encourage further clinical research to optimize treatment.

Keywords: cerebral oximetry; descriptive study; geriatric anesthesia; postoperative cognitive dysfunction; regional cerebral oxygen saturation.

Figure 1

Flowchart for investigative procedures.

Figure 2

Answer distribution on the clinical practice and cutoff value of cerebral oxygen saturation monitoring in respondents who owned cerebral oximetry. (A) Answer distribution on which surgery the respondents would monitor cerebral oxygen saturation. (B) Answer distribution of the question: “what cutoff value of the cerebral oxygen saturation declined from baseline during anesthesia should be intervened to avoid cerebral ischemia?”. (C) Answer distribution of the question: “which intervention would be chosen to improve hypoxia if cerebral oxygen saturation declined?”. (D) Answer distribution of the question: “Which anesthetic could be guided during cerebral oxygen saturation monitoring?”.

Figure 3

Summary of POCD evaluation and understanding the association between cerebral oxygen saturation monitoring and risk of POCD in respondents who owned cerebral oximetry.