Association between the variability of cerebral oxygen saturation during cardiopulmonary bypass and delayed postoperative neurocognitive recovery in cardiac valve surgical patients: A pilot study

Abstract

Aims of the study The association between regional cerebral oxygen saturation (rSO2) and postoperative cognitive decline is controversial. In this study, we investigated the association between the real variability of regional cerebral oxygen saturation during cardiopulmonary bypass (CPB) and postoperative delayed neurocognitive recovery in patients undergoing heart valve surgery. Methods used to conduct the study A total of 71 patients who underwent cardiac valve surgery were enrolled in this study. Patients were assessed for cognitive function using the Mini‐Mental State Examination (MMSE) and the Montreal Cognitive Assessment Scale (MOCA) on the day before surgery and the 7th day after surgery. The real variability of regional cerebral oxygen saturation (rSO2), real variability of the brain bispectral index of EEG (BIS), real variability of mean arterial pressure (MAP) and body temperature were monitored during CPB. Patients were divided into two groups according to neural cognitive function scores to explore the relationship between postoperative delayed neurocognitive recovery and the real variability of cerebral oxygen saturation, BIS, MAP, and body temperature during CPB. Results of the study Twenty‐seven patients were diagnosed with postoperative delayed neurocognitive recovery. The occurrence of postoperative delayed neurocognitive recovery after surgery was closely related to the large variability of rSO2 during the rewarming phase of CPB (P < .05). Logistic analysis showed that preoperative arrhythmia, a lower level of serum albumin after surgery and greater rSO2 variability during the rewarming phase were risk factors for postoperative delayed neurocognitive recovery (P < .05). In this study, there was no correlation between postoperative delayed neurocognitive recovery and BIS, MAP or body temperature variability (P > .05). Conclusions drawn from the study and clinical implications The real variability of rSO2 during the CPB rewarming phase was related to postoperative delayed neurocognitive recovery in patients who underwent cardiac surgery.

Anaesthesia‐related cognitive dysfunction following cardiothoracic surgery in late middle‐age and younger adults: A scoping review

“…POD is an acute change in cognitive function and significantly increases the risk of POCD. 48,49 Though the duration of anaesthesia, CPB, hospital stay and ICU stay were not different across studies, [22][23][24][25][26]28,32,34,41 the studies failed to consider the potential interaction effects of all these factors associated with anaesthesia type and medications. Schoen et al 21 assessed the relationship between the interaction of anaesthesia, duration and desaturation and cognitive test results (Trail-Making, Abbreviated Mental, Stroop Test and Word List).…”

“…In individuals less than 65 years, studies provide two types of findings: anaesthetics‐related adverse events associated with POCD 24,30,32,35–37,46 and intraoperative anaesthesia management (other than anaesthetics) 23,25,27,29,33,34,36,41 . It is found that intraoperative administration of ketamine 24 and dexmedetomidine 35 is associated with a decreased risk of POCD.…”

“…Also, most of the studies investigated POCD over a very short period of time (such as 3, 5, 6 and 7 days after surgery). 23,25,28,[32][33][34]37,40,41 Therefore, the results may be directly affected by practice effects, medications (such as opioids), symptoms such as pain and other acute mental conditions such as delirium. Only two studies 21,33 reported postoperative delirium, and just one 21 reported that delirium is a risk factor for POCD.…”

“…Two studies excluded females only. 20,21 Regarding the type of surgery, 17 studies (73.9%) reported openheart cardiopulmonary bypass (CPB), [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36] two studies (8.6%) noted off-pump coronary artery bypass (OPCAB) 37,38 and two studies (8.6%) reported both OPCAB and CPB. 20,29 Two studies (8.6%) did not report the type of surgical technique.…”

“…Eleven studies (47.8%) did not measure individual domains of cognition and rather reported overall function. 22,23,26,[29][30][31]33,34,36,37,42 Attention, 20,24,25,27,28,32,38,40,41 memory, 20,21,24,27,28,32,35,38,40 processing speed 24,25,37,38,41 and executive functioning 21,24,25,41 were the most frequently reported impaired domains of cognitive function (see Tables S1-S3).…”