Cerebral oximetry and postoperative delirium after cardiac surgery: a randomised, controlled trial

Differential responses of cerebral and renal oxygenation to altered perfusion conditions during experimental cardiopulmonary bypass in sheep

We tested whether the brain and kidney respond differently to cardiopulmonary bypass (CPB) and to changes in perfusion conditions during CPB. Therefore, in ovine CPB, we assessed regional cerebral oxygen saturation (rSO2 ) by near-infrared spectroscopy and renal cortical and medullary tissue oxygen tension (PO2 ), and, in some protocols, brain tissue PO2 , by phosphorescence lifetime oximetry. During CPB, rSO2 correlated with mixed venous SO2 (r = 0.78) and brain tissue PO2 (r = 0.49) when arterial PO2 was varied. During the first 30 min of CPB, brain tissue PO2 , rSO2 and renal cortical tissue PO2 did not fall, but renal medullary tissue PO2 did. Nevertheless, compared with stable anaesthesia, during stable CPB, rSO2 (66.8 decreasing to 61.3%) and both renal cortical (90.8 decreasing to 43.5 mm Hg) and medullary (44.3 decreasing to 19.2 mm Hg) tissue PO2 were lower. Both rSO2 and renal PO2 increased when pump flow was increased from 60 to 100 mL kg-1  min-1 at a target arterial pressure of 70 mm Hg. They also both increased when pump flow and arterial pressure were increased simultaneously. Neither was significantly altered by partially pulsatile flow. The vasopressor, metaraminol, dose-dependently decreased rSO2 , but increased renal cortical and medullary PO2 . Increasing blood haemoglobin concentration increased rSO2 , but not renal PO2 . We conclude that both the brain and kidney are susceptible to hypoxia during CPB, which can be alleviated by increasing pump flow, even without increasing arterial pressure. However, increasing blood haemoglobin concentration increases brain, but not kidney oxygenation, whereas vasopressor support with metaraminol increases kidney, but not brain oxygenation.

Effect of Esketamine on Postoperative Delirium in Patients Undergoing Cardiac Valve Replacement with Cardiopulmonary Bypass: A Randomized Controlled Trial

BACKGROUND

The aim of this study was to investigate the effects of esketamine on the risk of postoperative delirium (POD) in adults undergoing on-pump cardiac valve surgery.

METHODS

In this randomized, triple-blind, controlled trial, 116 adult patients with an American Society of Anesthesiologists (ASA) grade Ⅱ or Ⅲ and a New York Heart Association (NYHA) grade Ⅱ or Ⅲ who underwent cardiac valve surgery with cardiopulmonary bypass were included. Esketamine (0.25 mg/kg) or normal saline was administered intravenously before anesthesia induction. The primary outcome was POD, defined as a positive delirium assessment according to the 3-minute confusion assessment method (CAM) or the confusion assessment method for the intensive care unit (CAM-ICU) on a twice-daily basis for 7 days after surgery. Delirium duration and the delirium subtype were also recorded. The cognitive status of patients was measured according to the Mini-Mental State Examination at baseline, discharge, 30 days postoperatively and 3 months postoperatively.

RESULTS

A total of 112 patients (mean age, 52 years; 53.6% female) were enrolled; 56 were assigned to receive esketamine, and 56 were assigned to receive placebo. POD occurred in 13 (23.2%) patients in the esketamine group and in 25 (44.6%) patients in the placebo group (relative risk [RR], 0.52, 95% confidence interval [CI], 0.28-0.91; P = .018). Thirteen patients (23.2%) in the esketamine group and 24 (42.9%) patients in the placebo group had multiple episodes of delirium (RR, 0.54, 95% CI, 0.28-0.92), and 13 (23.2%) vs 22 (39.3%) patients exhibited the hyperactive subtype.

CONCLUSIONS

A single dose of esketamine (0.25 mg/kg) injected intravenously before anesthesia induction reduced the incidence of delirium in relatively young patients with ASA grade Ⅱ or Ⅲ who underwent on-pump cardiac surgery.

Identification of early delirium and its outcomes after cardiopulmonary bypass among adult patients with cardiovascular disease: a prospective observational study

Purpose

To identify the incidence and outcomes of postoperative delirium after cardiopulmonary bypass machine in adult cardiac surgery patients.

Method

A prospective observational study was conducted in a single-center institution in the Republic of China. This study included 273 patients who underwent cardiac surgical procedures requiring cardiopulmonary bypass machine utilization.

Results

This study used the Confusion Assessment Method to screen for delirium. Univariate analysis identified advanced age, emergency surgery and prolonged aortic cross-clamping time as significant predisposing factors for delirium, which occurred in 19.8% (n = 54) of cases and typically developed in average of 4.8 ± 3.28 days after the surgery. The analysis also identified that delirium was associated with increased complications and external referrals. A total of 142 patients (52.1%) were discharged to their homes, wherein the discharge rate in the delirium group was notably lower, with only 35.2% (n = 19) of patients, than in the delirium-free group with 56.2% (n = 123) of patients.

Conclusion

Considering the increased probability of delirium-related complications following cardiac surgery, it is important to develop effective preventive strategies for patients with perioperative risk factors, such as advanced age, emergency surgery and prolonged cross-clamp time, by implementing practical measures to minimize the risk of delirium.

Risk factors for postoperative delirium in elderly patients undergoing heart valve surgery with cardiopulmonary bypass

BACKGROUND

The aim of this study was to identify the risk factors for postoperative delirium (POD) in elderly patients undergoing heart valve surgery with cardiopulmonary bypass (CPB).

METHODS

Elderly patients undergoing elective heart valve surgery with CPB in The First Affiliated Hospital of Wenzhou Medical University between March 2022 and March 2023 were selected for this investigation. They were divided into a POD group and a non-POD group. Their baseline information was collected and recorded, and the patients were subjected to neurocognitive function assessment using the Mini-Mental State Examination and the Montreal Cognitive Assessment scales before surgery. We also recorded their intraoperative indicators such as duration of surgery, duration of CPB, duration of aortic cross-clamp, blood transfusion, and postoperative indicators such as duration of mechanical ventilation, postoperative 24-hour drainage volume, and pain score. Regional cerebral oxygen saturation was monitored intraoperatively by near-infrared spectroscopy based INVOS5100C Regional Oximeter. Patients were assessed for the occurrence of POD using Confusion Assessment Method for the Intensive Care Unit, and logistic regression analysis of risk factors for POD was performed.

RESULTS

The study finally included 132 patients, with 47 patients in the POD group and 85 ones in the non-POD group. There were no significant differences in baseline information and preoperative indicators between the two groups. However, marked differences were identified in duration of surgery, duration of CPB, duration of aortic cross-clamp, duration of postoperative mechanical ventilation, postoperative length of stay in cardiac intensive care unit, postoperative length of hospital stay, intraoperative blood transfusion, postoperative pain score, and postoperative 24-hour drainage volume between the two groups (p < 0.05). Additionally, the two groups had significant differences in rScO2 at each intraoperative time point and in the difference of rScO2 from baseline at each intraoperative time point (p < 0.05). Multivariate logistic regression analysis showed that duration of surgery > 285 min (OR, 1.021 [95% CI, 1.008-1.035]; p = 0.002), duration of postoperative mechanical ventilation > 23.5 h (OR, 6.210 [95% CI, 1.619-23.815]; p = 0.008), and postoperative CCU stay > 3.5 d (OR, 3.927 [95% CI, 1.046-14.735]; p = 0.043) were independent risk factors of the occurrence of POD while change of rScO2 at T1>50.5 (OR, 0.832 [95% CI 0.736-0.941]; p = 0.003) was a protective factor for POD.

CONCLUSION

Duration of surgery duration of postoperative mechanical ventilation and postoperative CCU stay are risk factors for POD while change of rScO2 at T1 is a protective factor for POD in elderly patients undergoing heart valve surgery with CPB.

Influence of Regional Nerve Block in Addition to General Anesthesia on Postoperative Delirium, Pain, and In-hospital Stay in Patients Undergoing Cardiothoracic Surgery: A Meta-analysis

ABSTRACT

This study aims to investigate whether venous injection of sedative agent or regional nerve block in alliance with major anesthesia could decrease the risk of postoperative delirium occurrence in patients receiving cardiothoracic surgery. Electronic academic databases were retrieved for related publications, and statistical software was used for data pooling and analysis. Forest plot was used to show the pooled sensitivity, specificity, and diagnostic odds ratio. Combined receiver operating characteristic curve was used to show the area under the curve of complex data. Seven studies were included for analysis. The risk of occurrence of delirium still showed no difference (risk rate = 0.93, 95% CI, 0.85-1.03) between the intervention group and placebo group. Postoperative pain feeling was more alleviated in patients with prophylactic application of regional nerve block. In addition, prophylactic application of regional nerve block could decrease the risk of postoperative in-hospital stay (risk rate = 0.28, 95% CI, 0.02-0.54). Our study demonstrated that, in elderly patients or pediatric patients undergoing cardiac surgery, prophylactic application of regional nerve block failed to decrease the incidence of postoperative delirium. However, the option of regional nerve block could decrease the duration of in-hospitalization stay and alleviate the acute pain during the postoperative period after open-heart surgery.

Effect of rScO2-Guided Blood Pressure Management on Postoperative Complications in Elderly Patients After Major Noncardiac Surgery: Protocol for a Randomized Controlled Trial

Background

Postoperative complications are common after major surgical procedures, leading to increased morbidity and mortality. Regional cerebral oxygen saturation (rScO2) reflects cerebral and global perfusion, and thus it can be used to guide hemodynamic management. We aim to explore the effect of rScO2-guided blood pressure management strategy on postoperative major complications in older adults who undergo major noncardiac surgery.

Methods

This randomized controlled clinical trial includes a total of 400 elderly patients receiving major noncardiac surgery and general anesthesia. Patients will be randomized (1:1) to one of two blood pressure management groups: a standard care group (targeting mean arterial pressure >65 mmHg or within 20% of baseline value), and a rScO2-guided group (absolute value of rScO2 >60% or decrease in rScO2 <10% of baseline). The primary outcome is the composite outcome of major complications (including infectious, respiratory, neurologic, cardiovascular, renal, thromboembolic gastrointestinal, and surgical complications) and deaths within the first 7 days after surgery. Secondary outcomes include the individual components of the primary outcome by day 7 after surgery and 30-day mortality. Data will be analyzed in the modified intention-to-treat population.

Discussion

This study will provide evidence for improving postoperative outcomes using the rScO2-guided blood pressure management among older adults who undergo major noncardiac surgery.

Trial Registration

Chinese Clinical Trial Registry (Identifier: ChiCTR2200060816).

Intraoperative neurological pupil index and postoperative delirium and neurologic adverse events after cardiac surgery: an observational study

Neurological pupil index (NPi) calculated by automated pupillometry predicts clinical outcomes in critically ill patients. However, there are few data on intraoperative NPi and postoperative outcome after cardiac surgery. We evaluated the relationships between intraoperative NPi and clinical outcomes, such as delirium, in cardiac surgery patients. NPi was measured at baseline, after anesthesia induction, at 30 min intervals after initiation of cardiopulmonary bypass or anastomosis of coronary artery bypass graft, and at skin closure. Abnormal NPi was defined as one or more measurements of NPi < 3.0 during surgery. The worst intraoperative NPi was recorded, then multivariate logistic regression analysis was performed to evaluate the relationship between abnormal NPi and postoperative delirium following cardiac surgery. Among 123 included patients, postoperative delirium developed in 19.5% (24/123) of patients. Intraoperative abnormal NPi was significantly associated with postoperative delirium (odds ratio 6.078; 95% confidence interval 1.845-20.025; P = 0.003) after adjustment for Society of Thoracic Surgeons Predicted Risk of Mortality score, coronary artery disease, and use of calcium channel blockers. In conclusion, abnormal intraoperative NPi independently predicted postoperative delirium following cardiac surgery. Intraoperative application of pupillometry may have prognostic value for development of postoperative delirium, thereby enabling close surveillance and early intervention in high-risk patients.Registry number: ClinicalTrials.gov (NCT04136210).

Dynamic predictive scores for cardiac surgery-associated agitated delirium: a single-center retrospective observational study

BACKGROUND

Prevention, screening, and early treatment are the aims of postoperative delirium management. The scoring system is an objective and effective tool to stratify potential delirium risk for patients undergoing cardiac surgery.

METHODS

Patients who underwent cardiac surgery between January 1, 2012, and January 1, 2019, were enrolled in our retrospective study. The patients were divided into a derivation cohort (n = 45,744) and a validation cohort (n = 11,436). The AD predictive systems were formulated using multivariate logistic regression analysis at three time points: preoperation, ICU admittance, and 24 h after ICU admittance.

RESULTS

The prevalence of AD after cardiac surgery in the whole cohort was 3.6% (2,085/57,180). The dynamic scoring system included preoperative LVEF ≤ 45%, serum creatinine > 100 µmol/L, emergency surgery, coronary artery disease, hemorrhage volume > 600 mL, intraoperative platelet or plasma use, and postoperative LVEF ≤ 45%. The area under the receiver operating characteristic curve (AUC) values for AD prediction were 0.68 (preoperative), 0.74 (on the day of ICU admission), and 0.75 (postoperative). The Hosmer‒Lemeshow test indicated that the calibration of the preoperative prediction model was poor (P = 0.01), whereas that of the pre- and intraoperative prediction model (P = 0.49) and the pre, intra- and postoperative prediction model (P = 0.35) was good.

CONCLUSIONS

Using perioperative data, we developed a dynamic scoring system for predicting the risk of AD following cardiac surgery. The dynamic scoring system may improve the early recognition of and the interventions for AD.

Monitoring the Cerebral Oximetry Index Along With In-line Cardiopulmonary Bypass Parameters in a High-Risk Patient Undergoing Cardiac Surgery: A Case Report

The quest to minimize the morbidity and mortality of patients undergoing cardiac surgery is ongoing. Impaired cerebral autoregulation and tissue malperfusion are linked with neurological complications. The cerebral oximetry index (COx) has been introduced as an index of cerebral autoregulation, while in-line monitoring enables the detection and prevention of metabolic disturbances during cardiopulmonary bypass (CPB). This report presents the case of a 58-year-old female patient scheduled for aortic valve replacement under minimally invasive extracorporeal circulation (MiECC). Her medical history consisted of epilepsy, multiple ischemic strokes, heavy smoking, and brachiocephalic artery stenosis. We sought to investigate the limits of autoregulation and the role of metabolic indices of perfusion on COx. Mean arterial blood pressure (ABP), cerebral oximetry (rSO₂), and in-line perfusion data during CPB were recorded at 10s intervals. The lower limit of autoregulation was 44mmHg on both sides and the upper limit was 98mmHg on the right and 107mmHg on the left side. A multiple linear regression analysis was performed to identify any potential predictors of COx values. Hemoglobin (Hb), PCO₂, flow, DO₂ index (DO₂i), Ο₂ extraction ratio (O₂ER), and perfusion ratio (PR) were included in the analysis. Significant equations were found on both sides. Predicted COx left was equal to 5.8 - 11.04O₂ER - 0.04Hb (p=0.001, R²= 0.15). Predicted COx right was equal to 3.06 - 0.3flow - 6.8O₂ER -0.03Hb + 0.02PCO₂ + 0.004DO₂i(p=0.03, R²=0.13). Targeting physiological perfusion and monitoring perfusion during CPB may have an additional impact on cerebral autoregulation and should be studied further.

The importance of monitoring cerebral oxygenation in non brain injured patients

Over the past few years, the use of non-invasive neuromonitoring in non-brain injured patients has increased, as a result of the recognition that many of these patients are at risk of brain injury in a wide number of clinical scenarios and therefore may benefit from its application which allows interventions to prevent injury and improve outcome. Among these, are post cardiac arrest syndrome, sepsis, liver failure, acute respiratory failure, and the perioperative settings where in the absence of a primary brain injury, certain groups of patients have high risk of neurological complications. While there are many neuromonitoring modalities utilized in brain injured patients, the majority of those are either invasive such as intracranial pressure monitoring, require special skill such as transcranial Doppler ultrasonography, or intermittent such as pupillometry and therefore unable to provide continuous monitoring. Cerebral oximetry using Near infrared Spectroscopy, is a simple non invasive continuous measure of cerebral oxygenation that has been shown to be useful in preventing cerebral hypoxemia both within the intensive care unit and the perioperative settings. At present, current recommendations for standard monitoring during anesthesia or in the general intensive care concentrate mainly on hemodynamic and respiratory monitoring without specific indications regarding the brain, and in particular, brain oximetry. The aim of this manuscript is to provide an up-to-date overview of the pathophysiology and applications of cerebral oxygenation in non brain injured patients as part of non-invasive multimodal neuromonitoring in the early identification and treatment of neurological complications in this population.

The safety and efficacy of remimazolam tosylate for induction and maintenance of general anesthesia in pediatric patients undergoing elective surgery: Study protocol for a multicenter, randomized, single-blind, positive-controlled clinical trial

Introduction: Remimazolam is an ultra-short-acting benzodiazepine sedative agent commonly used in general anesthesia, procedural sedation, and intensive care unit (ICU) sedation. This study aimed to explore the efficacy and safety of remimazolam versus propofol for the induction and maintenance of general anesthesia in preschool-age children undergoing elective surgery. Methods and analysis: In this multicenter, randomized, single-blind, positive-controlled non-inferior clinical trial, one hundred ninety-two children aged 3-6 years will be randomly allocated as a 3:1 ratio into two groups: Group R with an intravenous dose of remimazolam 0.3 mg/kg for the induction of anesthesia followed by a constant infusion rate of remimazolam 1-3 mg/kg/h to maintain anesthesia, and Group P with an intravenous dose of propofol 2.5 mg/kg for the induction of anesthesia followed by a constant infusion rate of propofol 4-12 mg/kg/h to maintain anesthesia. The primary outcome will be the rate of the successful induction and maintenance of anesthesia. The secondary outcomes will include the time to LoC, the Bispectral Index (BIS) value, awakening time, extubation time, post-anesthesia care unit (PACU) discharge time, usage of additional sedative drugs during the induction period, usage of remedial drugs in PACU, emergence delirium, pain in PACU, behavior scores at day 3 after surgery, parental and anesthesiologists' satisfaction, and adverse events. Ethics and dissemination: This study has been approved by the ethics review boards at all participating hospitals. The Ethics Committee of the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University (Reference No. LCKY 2020-380, November 13, 2020) is the central ethics committee.

A comprehensive review of cerebral oximetry in cardiac surgery

BACKGROUND

Patients who undergo cardiac surgery are at increased risk of stroke, postoperative cognitive decline, and delirium. These neurocognitive complications have led to increased costs, intensive care unit stays, morbidity, and mortality. As a result, there is a significant push to mitigate any neurological complications in cardiac surgery patients. Near-infrared spectroscopy to measure regional cerebral oxygen saturations has gained consideration due to its noninvasive and user-friendly nature. Cerebral oximetry desaturations during cardiac surgery have been linked to an array of adverse clinical outcomes. However, the most effective intraoperative interventions to protect this vulnerable patient population have yet to be ascertained.

AIM OF STUDY

To provide a comprehensive summary of the intraoperative management for cerebral oximetry desaturations during cardiac surgery. The review highlights clinical outcomes from cerebral oximetry use to quantify the importance of identifying cerebral desaturations during cardiac surgery. The review then interrogates possible interventions for cerebral oximetry desaturations in an effort to determine which interventions are most efficacious and to enlighten possible areas for further research.

METHODS

A narrative review of randomized controlled trials, observational studies, and systematic reviews with metanalyses was performed through August 2021.

RESULTS

There is significant heterogeneity among patient populations for which cerebral oximetry monitoring has been studied in cardiac surgery. Further, the definition of a clinically significant cerebral desaturation and the assessment of neurocognitive outcomes varied substantially across studies. As a result, metanalysis is challenging and few conclusions can be drawn. Cerebral oximetry use during cardiac surgery has not been associated with improvements in neurocognitive outcomes, morbidity, or mortality to date. The evidence to support a particular intervention for an acute desaturation is equivocal.

CONCLUSIONS

Future research is needed to quantify a clinically significant cerebral desaturation and to determine which interventions for an acute desaturation effectively improve clinical outcomes.

Pre- and intraoperative cerebral near-infrared spectroscopy and postoperative delirium: Results of a prospective cross-sectional trial

Postoperative delirium (PODE) is a serious complication that can occur during the first few days after surgery. A number of causes can make delirium more likely; one factor to consider is hypoxia during anesthesia. In this study, the pre- and intraoperative cerebral regional oxygen saturation (rSO2) as measured by near-infrared spectroscopy (NIRS) was to be examined with regard to an association with the occurrence of PODE in patients undergoing major abdominal procedures. Data from 80 patients (33 women, 47 men) was examined. The mean age was 66.31 ± 10.55 years (between 42 and 84 years). Thirteen patients developed PODE. The preoperative rSO2 values (P = .10) and the rSO2 values during the steady state of anesthesia (P = .06) tended to be lower in the delirium group than in the non-delirium group. There was a significant correlation between the preoperative rSO2 and the preoperative hemoglobin values (P < .001). The variance of rSO2 during the steady state of anesthesia was significantly greater in the delirium group compared to the non-delirium group (P = .03). In two patients from the delirium group, rSO2 dropped below 50%; they also had a minimum mean arterial pressure below 50 mm Hg, which could have disturbed cerebral autoregulation. The duration of rSO2 decreases (>10%, >15%, >20%) and increases (>10%) compared to the preoperative values was not significantly different between patients with and without PODE. The results suggest that NIRS could be a useful monitoring method for patients undergoing abdominal surgical procedures, on the one hand to recognize patients with low pre- or intraoperative rSO2 values, and on the other hand to detect changes in rSO2 values during anesthesia.

A novel predictive strategy for the incidence of postoperative neurocognitive dysfunction in elderly patients with mild cognitive impairment

Objective: Preoperative levels of cognition-related biomarkers and intraoperative cerebral ischemia and hypoxia might cause postoperative neurocognitive dysfunction (PND). The aim of this study was to evaluate the predictive ability of preoperative plasma biomarkers along with cerebral oxygen saturation (SctO₂) for the incidence of PND in elderly patients with mild cognitive impairment (MCI).

Methods: A total of 210 patients aged 65–80 years undergoing spinal surgery were randomly assigned to three groups (n = 70 each): propofol, sevoflurane, and propofol/sevoflurane as anesthesia maintenance protocols. Propofol was administrated target-controlled infusion of 4 μg/ml (group P), the minimum alveolar concentration (MAC) of inhalation anesthetic sevoflurane was 1.3 (group S), and propofol was injected with a target-controlled plasma concentration of 1.2 μg/ml, accompanied by sevoflurane inhalation 0.7 MAC (group PS). Cognitive function was evaluated 1 day preoperatively and on the 7th day postoperatively. Preoperative levels of amyloidβ-40 (Aβ-40), Aβ-42, total tau protein (T-tau), phosphorylated tau protein (P-tau), and triggering receptors on myeloid cells-2 (TREM2) were investigated. SctO₂ was monitored intraoperatively.

Results: Aβ-42 had the strongest significant correlation with preoperative MoCA score. The value of Aβ-42 associated with a high risk of PND was 28.34 pg/ml, and the area under the curve (AUC) was predicted to be 0.711. When the preoperative level of Aβ-42 was 28.34 pg/ml, SctO_2max% was 9.92%. The AUC was predicted to be 0.872, and the sensitivity and specificity were 0.833 and 0.841, respectively.

Conclusion: Under the conditions of preoperative Aβ-42 less than 28.34 pg/ml, the intraoperative fluctuation range of cerebral oxygen saturation should be maintained within 9.92% to reduce the occurrence of PND in geriatric patients with MCI.

Effects of intravenous lidocaine on hypoxemia induced by propofol-based sedation for gastrointestinal endoscopy procedures: study protocol for a prospective, randomized, controlled trial

Background

Oxygen-desaturation episodes, blood pressure drops, and involuntary body movement are common problems that occur in propofol-based sedation in the procedure of painless gastrointestinal (GI) endoscopy. As a widely used analgesic adjuvant, intravenous lidocaine can reduce the consumption of propofol during ERCP or colonoscopy. However, it is still unknown how lidocaine affects the incidence of oxygen-desaturation episodes and cardiovascular events, and involuntary movement during painless GI endoscopy. Therefore, we aimed to assess the effectiveness and safety of intravenous lidocaine in propofol-based sedation for GI endoscopy.

Methods

We will conduct a single-center, prospective, randomized, double-blind, saline-controlled trial. A total number of 300 patients undergoing painless GI procedures will be enrolled and randomly divided into the lidocaine group (Group L) and the control group (Group C). After midazolam and sufentanil intravenous injection, a bolus of 1.5 mg/kg lidocaine was immediately injected and followed by a continuous infusion of 4 mg/kg/h in the lidocaine group, whereas the same volumes of saline solution in the control group. Then, propofol was titrated to produce unconsciousness during the procedure. The primary outcome will be the incidence of oxygen-desaturation episodes. Secondary outcomes will be the incidence of involuntary body movement, discomfort symptoms, propofol consumption, endoscopist, and patient satisfaction.

Discussion

Propofol-based deep sedation without intubation is widely used in painless GI endoscopy. However, adverse events such as hypoxemia often occur clinically. We expect to assess the effect of lidocaine on reducing the incidence of oxygen-desaturation episodes, cardiovascular events, and involuntary body movement. We believe that the results of this trial will provide an effective and safe method for painless GI endoscopy.

Trial registration

Chinese Clinical Trial Registry ChiCTR2100053818. Registered on 30 November 2021.

Perioperative neurocognitive disorders: A narrative review focusing on diagnosis, prevention, and treatment

Perioperative neurocognitive disorders (NCDs) refer to neurocognitive abnormalities detected during the perioperative periods, including preexisting cognitive impairment, preoperative delirium, delirium occurring up to 7 days after surgery, delayed neurocognitive recovery, and postoperative NCD. The Diagnostic and Statistical Manual of Mental Disorders‐5th edition (DSM‐5) is the golden standard for diagnosing perioperative NCDs. Given the impracticality of using the DSM‐5 by non‐psychiatric practitioners, many diagnostic tools have been developed and validated for different clinical scenarios. The etiology of perioperative NCDs is multifactorial and includes predisposing and precipitating factors. Identifying these risk factors is conducive to preoperative risk stratification and perioperative risk reduction. Prevention for perioperative NCDs should include avoiding possible contributors and implementing nonpharmacologic and pharmacological interventions. The former generally includes avoiding benzodiazepines, anticholinergics, prolonged liquid fasting, deep anesthesia, cerebral oxygen desaturation, and intraoperative hypothermia. Nonpharmacologic measures include preoperative cognitive prehabilitation, comprehensive geriatric assessment, implementing fast‐track surgery, combined use of regional block, and sleep promotion. Pharmacological measures including dexmedetomidine, nonsteroidal anti‐inflammatory drugs, and acetaminophen are found to have beneficial effects. Nonpharmacological treatments are the first‐line measures for established perioperative NCDs. Pharmacological treatments are still limited to severely agitated or distressed patients.

How to Study the Brain While Anesthetizing It?! A Scoping Review on Running Neuroanesthesiologic Studies and Trials That Include Neurosurgical Patients

This scoping review addresses the challenges of neuroanesthesiologic research: the population, the methods/treatment/exposure, and the outcome/results. These challenges are put into the context of a future research agenda for peri-/intraoperative anesthetic management, neurocritical care, and applied neurosciences. Finally, the opportunities of adaptive trial design in neuroanesthesiologic research are discussed.

Cerebral Tissue Oxygen Saturation Is Enhanced in Patients following Transcatheter Aortic Valve Implantation: A Retrospective Study

Transcatheter aortic valve implantation (TAVI) has emerged as an alternative to surgical aortic valve replacement. The aim of this study was to evaluate whether a relevant alteration in cerebral tissue oxygen saturation (rSO2) could be detected following TAVI. Retrospective data analysis included 275 patients undergoing TAVI between October 2016 and December 2020. Overall, rSO2 significantly increased following TAVI (64.6 ± 10% vs. 68.1 ± 10%, p < 0.01). However, a significant rise was only observed in patients with a preoperative rSO2 < 60%. Of the hemodynamic confounders studied, hemoglobin, mean arterial pressure and blood pH were lowered, while central venous pressure and arterial partial pressure of carbon dioxide (PaCO2) were slightly elevated (PaCO2: 39 (36−43) mmHg vs. 42 (37−47) mmHg, p = 0.03; pH: 7.41 (7.3−7.4) vs. 7.36 (7.3−7.4), p < 0.01). Multivariate linear regression modeling identified only hemoglobin as a predictor of altered rSO2. Patients with a EuroScore II above 4% and an extended ICU stay were found to have lower rSO2, while no difference was observed in patients with postoperative delirium or between the implanted valve types. Further prospective studies that eliminate differences in potential confounding variables are necessary to confirm the rise in rSO2. Future research should provide more information on the value of cerebral oximetry for identifying high-risk patients who will require further clinical interventions in the setting of the TAVI procedure.

Cerebral near-infrared spectroscopy monitoring (NIRS) in children and adults: a systematic review with meta-analysis

BACKGROUND

Cerebral oxygenation monitoring utilising near-infrared spectroscopy (NIRS) is increasingly used to guide interventions in clinical care. The objective of this systematic review with meta-analysis and Trial Sequential Analysis is to evaluate the effects of clinical care with access to cerebral NIRS monitoring in children and adults versus care without.

METHODS

This review conforms to PRISMA guidelines and was registered in PROSPERO (CRD42020202986). Methods are outlined in our protocol (doi: 10.1186/s13643-021-01660-2).

RESULTS

Twenty-five randomised clinical trials were included (2606 participants). All trials were at a high risk of bias. Two trials assessed the effects of NIRS during neonatal intensive care, 13 during cardiac surgery, 9 during non-cardiac surgery and 1 during neurocritical care. Meta-analyses showed no significant difference for all-cause mortality (RR 0.75, 95% CI 0.51-1.10; 1489 participants; I2 = 0; 11 trials; very low certainty of evidence); moderate or severe, persistent cognitive or neurological deficit (RR 0.74, 95% CI 0.42-1.32; 1135 participants; I2 = 39.6; 9 trials; very low certainty of evidence); and serious adverse events (RR 0.82; 95% CI 0.67-1.01; 2132 participants; I2 = 68.4; 17 trials; very low certainty of evidence).

CONCLUSION

The evidence on the effects of clinical care with access to cerebral NIRS monitoring is very uncertain.

IMPACT

The evidence of the effects of cerebral NIRS versus no NIRS monitoring are very uncertain for mortality, neuroprotection, and serious adverse events. Additional trials to obtain sufficient information size, focusing on lowering bias risk, are required. The first attempt to systematically review randomised clinical trials with meta-analysis to evaluate the effects of cerebral NIRS monitoring by pooling data across various clinical settings. Despite pooling data across clinical settings, study interpretation was not substantially impacted by heterogeneity. We have insufficient evidence to support or reject the clinical use of cerebral NIRS monitoring.

The Effect of Intraoperative Cerebral Oximetry Monitoring on Postoperative Cognitive Dysfunction and ICU Stay in Adult Patients Undergoing Cardiac Surgery: An Updated Systematic Review and Meta-Analysis

Aim

Determining whether intraoperative cerebral oximetry monitoring-guided intervention reduces the risk of postoperative cognitive dysfunction remains controversial. The objective of this study was to conduct an up-to-date meta-analysis to comprehensively assess the effects of regional cerebral oxygen saturation (rSO₂) monitoring-guided intervention on cognitive outcomes after cardiac surgery.

Methods

PubMed, EMBASE, Ovid, and Cochrane Library databases were systematically searched using the related keywords for cardiac surgical randomized-controlled trials (RCTs) published from their inception to July 31, 2021. The primary outcome was postoperative delirium (POD). The secondary outcomes were postoperative cognitive decline (POCD) and other major postoperative outcomes. The odds ratio (OR) or weighted mean differences (WMDs) with 95% confidence interval (CI) were used to pool the data. The random-effect model was used for the potential clinical inconsistency. We performed meta-regression and subgroup analyses to assess the possible influence of rSO₂ monitoring-guided intervention on clinical outcomes.

Results

In total, 12 RCTs with 1,868 cardiac surgical patients were included. Compared with controls, the incidences of POD (n = 6 trials; OR, 0.28; 95% CI, 0.09–0.84; p = 0.02; I² = 81%) and POCD (n = 5 trials; OR, 0.38; 95% CI, 0.16–0.93; p = 0.03; I² = 78%) were significantly lower in the intervention group. Cerebral oximetry desaturation also showed a positive association with the incidence of POD (n = 5 trials; OR, 2.02; 95% CI, 1.25–3.24; p = 0.004; I² = 81%). The duration of intensive care unit (ICU) stay was markedly shorter in the intervention group than in the control group (n = 10 trials; WMD, −0.22 days; 95% CI, −0.44 to −0.00; p = 0.05; I² = 74%). Univariate meta-regression analyses showed that the major sources of heterogeneity were age (p = 0.03), body mass index (BMI, p = 0.05), and the proportion of congenital heart disease (CHD, p = 0.02) for POD, age (p = 0.04) for POCD, diabetes mellitus (DM, p = 0.07), cerebrovascular accident (CVA, p = 0.02), and chronic obstructive pulmonary disease (COPD, p = 0.09) for ICU stay. Subsequent subgroup analyses also confirmed these results.

Conclusion

Available evidence from the present study suggests that an intraoperative cerebral oximetry desaturation is associated with an increased POD risk, and the rSO₂ monitoring-guided intervention is correlated with a lower risk of POD and POCD, and a shorter ICU stay in adults undergoing cardiac surgery. These clinical benefits may be limited in patients with older age, diabetes status, high BMI, non-CHD, non-COPD, or a previous cardiovascular accident.

Systematic Review Registration: [PROSPREO], identifier: [CRD42021252654].

Association between the reactivity of local cerebral oxygen saturation after hypo-to-hypercapnic tests and delirium after abdominal surgery in older adults: A prospective study

OBJECTIVE

This study aimed to investigate the correlation between changes in regional cerebral oxygen saturation (rSO2) and postoperative delirium in older adults undergoing major abdominal surgery.

MATERIALS AND METHODS

This prospective study enrolled older adults scheduled for elective major abdominal surgery at the Second Affiliated Hospital of Anhui Medical University from August 2021 to January 2022. The change in rSO2 from baseline was determined using the hypo-to-hypercapnic test. The main study outcome was the occurrence of postoperative delirium.

RESULTS

A total of 101 participants were included for analysis, of whom 16 (15.8%) developed postoperative delirium. Compared with non-delirium participants, the mean arterial pressure and heart rate were not significantly different in the postoperative delirium group at T0, T1, T2, T3, T4, and T6 (all P_interaction > 0.05), but the delirium group had lower pH, lower PaO2, and higher lactate levels at T4, T5, and T6 (all P_interaction < 0.05). rSO2 at T0, T1, T2, T3, T4, and T6 was 69.0 (63.2-75.2), 70.7 ± 7.3, 68.2 ± 7.5, 72.1 ± 8.0, 69.9 ± 7.8, 67.4 ± 7.2, and 71.7 ± 8.1, respectively. The postoperative change in rSO2 during the hypercapnia test (TΔrSO2%) was 6.62 (5.31-9.36). Multivariable analysis showed that the Cumulative Illness Rating Scale (odd ratio, OR = 1.89, 95% confidence interval, CI: 1.10-3.25, P = 0.021), preoperative albumin levels (OR = 0.67, 95% CI: 0.48-0.94, P = 0.022), rSO2 at T4 (OR = 0.61, 95% CI: 0.41-0.89, P = 0.010), and postoperative TΔrSO2% (OR = 0.80, 95% CI: 0.66-0.98, P = 0.028) were independently associated with postoperative delirium in older adults undergoing elective abdominal surgery.

CONCLUSION

The rSO2 measured at T4 and postoperative TΔrSO2% were independently associated with postoperative delirium in older adults undergoing elective abdominal surgery.

The use of cerebral oximetry in cardiac surgery: A systematic review and meta-analysis of randomized controlled trials

High prevalence of cerebral desaturation is associated with postoperative neurological complications in cardiac surgery. However, the evidence use of cerebral oximetry by correcting cerebral desaturation in the reduction of postoperative complications remains uncertain in the literature. This systematic review and meta-analysis aimed to examine the effect of cerebral oximetry on the incidence of postoperative cognitive dysfunction in cardiac surgery. Databases of MEDLINE, EMBASE, and CENTRAL were searched from their inception until April 2021. All randomized controlled trials comparing cerebral oximetry and blinded/no cerebral oximetry in adult patients undergoing cardiac surgery were included. Observational studies, case series, and case reports were excluded. A total of 14 trials (n = 2,033) were included in this review. Our pooled data demonstrated that patients with cerebral oximetry were associated with a lower incidence of postoperative cognitive dysfunction than the control group (studies = 4, n = 609, odds ratio [OR]: 0.15, 95% confidence interval [CI]: 0.04 to 0.54, P = 0.003, I² = 88%; certainty of evidence = very low). In terms of postoperative delirium (OR: 0.75, 95%CI: 0.50-1.14, P = 0.18, I² = 0%; certainty of evidence = low) and postoperative stroke (OR: 0.81 95%CI: 0.37-1.80, P = 0.61, I² = 0%; certainty of evidence = high), no significant differences (P > 0.05) were reported between the cerebral oximetry and control groups. In this meta-analysis, the use of cerebral oximetry monitoring in cardiac surgery demonstrated a lower incidence of postoperative cognitive dysfunction. However, this finding must be interpreted with caution due to the low level of evidence, high degree of heterogeneity, lack of standardized cognitive assessments, and cerebral desaturation interventions.

Cerebral monitoring in surgical ICU patients

PURPOSE OF REVIEW

To give an overview of cerebral monitoring techniques for surgical ICU patients.

RECENT FINDINGS

As the burden of postsurgical neurological and neurocognitive complications becomes increasingly recognized, cerebral monitoring in the surgical ICU might gain a relevant role in detecting and possibly preventing adverse outcomes. However, identifying neurological alterations in surgical ICU patients, who are often sedated and mechanically ventilated, can be challenging. Various noninvasive and invasive techniques are available for cerebral monitoring, providing an assessment of cortical electrical activity, cerebral oxygenation, blood flow autoregulation, intracranial pressure, and cerebral metabolism. These techniques can be used for the diagnosis of subclinical seizures, the assessment of sedation depth and delirium, the detection of an impaired cerebral blood flow, and the diagnosis of neurosurgical complications.

SUMMARY

Cerebral monitoring can be a valuable tool in the early detection of adverse outcomes in surgical ICU patients, but the evidence is limited, and clear clinical indications are still lacking.

Non-pharmacological interventions for preventing delirium in hospitalised non-ICU patients

BACKGROUND

Delirium is an acute neuropsychological disorder that is common in hospitalised patients. It can be distressing to patients and carers and it is associated with serious adverse outcomes. Treatment options for established delirium are limited and so prevention of delirium is desirable. Non-pharmacological interventions are thought to be important in delirium prevention.  OBJECTIVES: To assess the effectiveness of non-pharmacological interventions designed to prevent delirium in hospitalised patients outside intensive care units (ICU).

SEARCH METHODS

We searched ALOIS, the specialised register of the Cochrane Dementia and Cognitive Improvement Group, with additional searches conducted in MEDLINE, Embase, PsycINFO, CINAHL, LILACS, Web of Science Core Collection, ClinicalTrials.gov and the World Health Organization Portal/ICTRP to 16 September 2020. There were no language or date restrictions applied to the electronic searches, and no methodological filters were used to restrict the search.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of single and multicomponent non-pharmacological interventions for preventing delirium in hospitalised adults cared for outside intensive care or high dependency settings. We only included non-pharmacological interventions which were designed and implemented to prevent delirium.  DATA COLLECTION AND ANALYSIS: Two review authors independently examined titles and abstracts identified by the search for eligibility and extracted data from full-text articles. Any disagreements on eligibility and inclusion were resolved by consensus. We used standard Cochrane methodological procedures. The primary outcomes were: incidence of delirium; inpatient and later mortality; and new diagnosis of dementia. We included secondary and adverse outcomes as pre-specified in the review protocol. We used risk ratios (RRs) as measures of treatment effect for dichotomous outcomes and between-group mean differences for continuous outcomes. The certainty of the evidence was assessed using GRADE. A complementary exploratory analysis was undertaker using a Bayesian component network meta-analysis fixed-effect model to evaluate the comparative effectiveness of the individual components of multicomponent interventions and describe which components were most strongly associated with reducing the incidence of delirium.

MAIN RESULTS

We included 22 RCTs that recruited a total of 5718 adult participants. Fourteen trials compared a multicomponent delirium prevention intervention with usual care. Two trials compared liberal and restrictive blood transfusion thresholds. The remaining six trials each investigated a different non-pharmacological intervention. Incidence of delirium was reported in all studies.  Using the Cochrane risk of bias tool, we identified risks of bias in all included trials. All were at high risk of performance bias as participants and personnel were not blinded to the interventions. Nine trials were at high risk of detection bias due to lack of blinding of outcome assessors and three more were at unclear risk in this domain.  Pooled data showed that multi-component non-pharmacological interventions probably reduce the incidence of delirium compared to usual care (10.5% incidence in the intervention group, compared to 18.4% in the control group, risk ratio (RR) 0.57, 95% confidence interval (CI) 0.46 to 0.71, I² = 39%; 14 studies; 3693 participants; moderate-certainty evidence, downgraded due to risk of bias).  There may be little or no effect of multicomponent interventions on inpatient mortality compared to usual care (5.2% in the intervention group, compared to 4.5% in the control group, RR 1.17, 95% CI 0.79 to 1.74, I² = 15%; 10 studies; 2640 participants; low-certainty evidence downgraded due to inconsistency and imprecision).  No studies of multicomponent interventions reported data on new diagnoses of dementia.  Multicomponent interventions may result in a small reduction of around a day in the duration of a delirium episode (mean difference (MD) -0.93, 95% CI -2.01 to 0.14 days, I² = 65%; 351 participants; low-certainty evidence downgraded due to risk of bias and imprecision). The evidence is very uncertain about the effect of multicomponent interventions on delirium severity (standardised mean difference (SMD) -0.49, 95% CI -1.13 to 0.14, I²=64%; 147 participants; very low-certainty evidence downgraded due to risk of bias and serious imprecision). Multicomponent interventions may result in a reduction in hospital length of stay compared to usual care (MD -1.30 days, 95% CI -2.56 to -0.04 days, I²=91%; 3351 participants; low-certainty evidence downgraded due to risk of bias and inconsistency), but little to no difference in new care home admission at the time of hospital discharge (RR 0.77, 95% CI 0.55 to 1.07; 536 participants; low-certainty evidence downgraded due to risk of bias and imprecision). Reporting of other adverse outcomes was limited.  Our exploratory component network meta-analysis found that re-orientation (including use of familiar objects), cognitive stimulation and sleep hygiene were associated with reduced risk of incident delirium. Attention to nutrition and hydration, oxygenation, medication review, assessment of mood and bowel and bladder care were probably associated with a reduction in incident delirium but estimates included the possibility of no benefit or harm.  Reducing sensory deprivation, identification of infection, mobilisation and pain control all had summary estimates that suggested potential increases in delirium incidence, but the uncertainty in the estimates was substantial.  Evidence from two trials suggests that use of a liberal transfusion threshold over a restrictive transfusion threshold probably results in little to no difference in incident delirium (RR 0.92, 95% CI 0.62 to 1.36; I² = 9%; 294 participants; moderate-certainty evidence downgraded due to risk of bias).  Six other interventions were examined, but evidence for each was limited to single studies and we identified no evidence of delirium prevention.  AUTHORS' CONCLUSIONS: There is moderate-certainty evidence regarding the benefit of multicomponent non-pharmacological interventions for the prevention of delirium in hospitalised adults, estimated to reduce incidence by 43% compared to usual care. We found no evidence of an effect on mortality. There is emerging evidence that these interventions may reduce hospital length of stay, with a trend towards reduced delirium duration, although the effect on delirium severity remains uncertain. Further research should focus on implementation and detailed analysis of the components of the interventions to support more effective, tailored practice recommendations.

The Use of Cerebral Oximetry in Surgery: A Systematic Review and Meta-analysis of Randomized Controlled Trials

OBJECTIVE

The evidence on the use of cerebral oximetry during surgery to minimize postoperative neurologic complications remains uncertain in the literature. The present authors aimed to assess the value of cerebral oximetry in the prevention of postoperative cognitive dysfunction, postoperative delirium, and postoperative stroke in adults undergoing surgery.

DESIGN

A systematic review and meta-analysis.

SETTING

The surgery room.

PARTICIPANTS

Adult patients (ages ≥18 years) undergoing surgery.

INTERVENTIONS

Cerebral oximetry monitoring.

MEASUREMENTS AND MAIN RESULTS

Databases of Ovid MEDLINE, Ovid EMBASE, and CENTRAL were systematically searched from their inception until December 2020 for randomized controlled trials comparing cerebral oximetry monitoring with either blinded or no cerebral oximetry monitoring in adults undergoing surgery. Observational studies, case reports, and case series were excluded. Seventeen studies (n = 2,120 patients) were included for quantitative meta-analysis. Patients who were randomized to cerebral oximetry monitoring had a lower incidence of postoperative cognitive dysfunction (studies = seven, n = 969, odds ratio [OR] 0.23, 95% confidence interval [CI] 0.11-0.48, p = 0.0001; evidence = very low). However, no significant differences were observed in the incidence of postoperative delirium (studies = five, n = 716, OR 0.81, 95% CI 0.53-1.25, p = 0.35; evidence = high), and postoperative stroke (studies = seven, n = 1,087, OR 0.72, 95% CI 0.30-1.69, p = 0.45; evidence = moderate).

CONCLUSION

Adult patients with cerebral oximetry monitoring were associated with a significant reduction of postoperative cognitive dysfunction. However, given the low certainty of evidence and substantial heterogeneity, more randomized controlled trials using standardized assessment tools for postoperative cognitive dysfunction and interventions of correcting cerebral desaturation are warranted to improve the certainty of evidence and homogeneity.

Prolonged postoperative cerebral oxygen desaturation after cardiac surgery: A prospective observational study

BACKGROUND

Near-infrared spectroscopy (NIRS) is used routinely to monitor cerebral tissue oxygen saturation (SctO2) during cardiopulmonary bypass (CPB) but is rarely employed outside the operating room. Previous studies indicate that patients are at risk of postoperative cerebral oxygen desaturation after cardiac surgery.

OBJECTIVES

We aimed to assess perioperative and postoperative changes in NIRS-derived SctO2 in cardiac surgery patients.

DESIGN

Prospective observational study.

SETTING

The study was conducted in a tertiary referral university hospital in Australia from December 2017 to December 2018.

PATIENTS

We studied 34 adult patients (70.6% men) undergoing cardiac surgery requiring CPB and a reference group of 36 patients undergoing non-cardiac surgical procedures under general anaesthesia.

MAIN OUTCOME MEASURES

We measured SctO2 at baseline, during and after surgery, and then once daily until hospital discharge, for a maximum of 7 days. We used multivariate linear mixed-effects modelling to adjust for all relevant imbalances between the two groups.

RESULTS

In the cardiac surgery group, SctO2 was 63.7% [95% confidence interval (CI), 62.0 to 65.5] at baseline and 61.0% (95% CI, 59.1 to 62.9, P = 0.01) on arrival in the ICU. From day 2 to day 7 after cardiac surgery, SctO2 progressively declined. At hospital discharge, SctO2 was significantly lower than baseline, at 53.5% (95% CI, 51.8 to 55.2, P < 0.001). In the reference group, postoperative SctO2 was not significantly different from baseline. On multivariable analysis, cardiac surgery, peripheral vascular disease and time since the operation were associated with greater cerebral desaturation, whereas higher haemoglobin concentrations were associated with slightly better cerebral oxygenation.

CONCLUSION

After cardiac surgery on CPB, but not after non-cardiac surgery, most patients experience prolonged cerebral desaturation. Such postoperative desaturation remained unresolved 7 days after surgery. The underlying mechanisms and time to resolution of such cerebral desaturations require further investigation.

Effects of perioperative interventions for preventing postoperative delirium: A protocol for systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Postoperative delirium (POD) not only increases the medical burden but also adversely affects patient prognosis. Although some cases of delirium can be avoided by early intervention, there is no clear evidence indicating whether any of these measures can effectively prevent POD in specific patient groups.

OBJECTIVE

The aim of this meta-analysis was to compare the efficacy and safety of the existing preventive measures for managing POD.

METHODS

The PubMed, OVID (Embase and MEDLINE), Web of Science, and the Cochrane Library databases were searched for articles published before January 2020. The relevant randomized controlled trials (RCTs) were selected based on the inclusion and exclusion criteria. Data extraction and methodological quality assessment were performed according to a predesigned data extraction form and scoring system, respectively. The interventions were compared on the basis of the primary outcome like incidence of POD, and secondary outcomes like duration of delirium and the length of intensive care unit and hospital stay.

RESULTS

Sixty-three RCTs were included in the study, covering interventions like surgery, anesthesia, analgesics, intraoperative blood glucose control, cholinesterase inhibitors, anticonvulsant drugs, antipsychotic drugs, sleep rhythmic regulation, and multi-modal nursing. The occurrence of POD was low in 4 trials that monitored the depth of anesthesia with bispectral index during the operation (P < .0001). Two studies showed that supplementary analgesia was useful for delirium prevention (P = .002). Seventeen studies showed that perioperative sedation with α2-adrenergic receptor agonists prevented POD (P = .0006). Six studies showed that both typical and atypical antipsychotic drugs can reduce the incidence of POD (P = .002). Multimodal nursing during the perioperative period effectively reduced POD in 6 studies (P < .00001). Furthermore, these preventive measures can reduce the duration of delirium, as well as the total and postoperative length of hospitalized stay for non-cardiac surgery patients. For patients undergoing cardiac surgery, effective prevention can only reduce the length of intensive care unit stay.

CONCLUSION

Measures including intraoperative monitoring of bispectral index, supplemental analgesia, α2-adrenergic receptor agonists, antipsychotic drugs, and multimodal care are helpful to prevent POD effectively. However, larger, high-quality RCTs are needed to verify these findings and develop more interventions and drugs for preventing postoperative delirium.

Neuromonitoring and Neurocognitive Outcomes in Cardiac Surgery: A Narrative Review

Neurocognitive dysfunction after cardiac surgery can present with diverse clinical phenotypes, which include postoperative delirium, postoperative cognitive dysfunction, and stroke, and it presents a significant healthcare burden for both patients and providers. Neurologic monitoring during cardiac surgery includes several modalities assessing cerebral perfusion and oxygenation (near-infrared spectroscopy, transcranial Doppler and jugular venous bulb saturation monitoring) and those that measure cerebral function (processed and unprocessed electroencephalogram), reflecting an absence of a single, definitive neuromonitor. This narrative review briefly describes the technologic basis of these neuromonitoring modalities, before exploring their use in clinical practice, both as tools to predict neurocognitive dysfunction, and with a bundle of interventions designed to optimize cerebral oxygen supply, with the aim of reducing postoperative delirium and cognitive dysfunction following cardiac surgery.

Non-pharmacological interventions for preventing delirium in hospitalised non-ICU patients

BACKGROUND

Delirium is an acute neuropsychological disorder that is common in hospitalised patients. It can be distressing to patients and carers and it is associated with serious adverse outcomes. Treatment options for established delirium are limited and so prevention of delirium is desirable. Non-pharmacological interventions are thought to be important in delirium prevention.  OBJECTIVES: To assess the effectiveness of non-pharmacological interventions designed to prevent delirium in hospitalised patients outside intensive care units (ICU).

SEARCH METHODS

We searched ALOIS, the specialised register of the Cochrane Dementia and Cognitive Improvement Group, with additional searches conducted in MEDLINE, Embase, PsycINFO, CINAHL, LILACS, Web of Science Core Collection, ClinicalTrials.gov and the World Health Organization Portal/ICTRP to 16 September 2020. There were no language or date restrictions applied to the electronic searches, and no methodological filters were used to restrict the search.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of single and multicomponent non-pharmacological interventions for preventing delirium in hospitalised adults cared for outside intensive care or high dependency settings. We only included non-pharmacological interventions which were designed and implemented to prevent delirium.  DATA COLLECTION AND ANALYSIS: Two review authors independently examined titles and abstracts identified by the search for eligibility and extracted data from full-text articles. Any disagreements on eligibility and inclusion were resolved by consensus. We used standard Cochrane methodological procedures. The primary outcomes were: incidence of delirium; inpatient and later mortality; and new diagnosis of dementia. We included secondary and adverse outcomes as pre-specified in the review protocol. We used risk ratios (RRs) as measures of treatment effect for dichotomous outcomes and between-group mean differences for continuous outcomes. The certainty of the evidence was assessed using GRADE. A complementary exploratory analysis was undertaker using a Bayesian component network meta-analysis fixed-effect model to evaluate the comparative effectiveness of the individual components of multicomponent interventions and describe which components were most strongly associated with reducing the incidence of delirium.

MAIN RESULTS

We included 22 RCTs that recruited a total of 5718 adult participants. Fourteen trials compared a multicomponent delirium prevention intervention with usual care. Two trials compared liberal and restrictive blood transfusion thresholds. The remaining six trials each investigated a different non-pharmacological intervention. Incidence of delirium was reported in all studies.  Using the Cochrane risk of bias tool, we identified risks of bias in all included trials. All were at high risk of performance bias as participants and personnel were not blinded to the interventions. Nine trials were at high risk of detection bias due to lack of blinding of outcome assessors and three more were at unclear risk in this domain.  Pooled data showed that multi-component non-pharmacological interventions probably reduce the incidence of delirium compared to usual care (10.5% incidence in the intervention group, compared to 18.4% in the control group, risk ratio (RR) 0.57, 95% confidence interval (CI) 0.46 to 0.71, I2 = 39%; 14 studies; 3693 participants; moderate-certainty evidence, downgraded due to risk of bias).  There may be little or no effect of multicomponent interventions on inpatient mortality compared to usual care (5.2% in the intervention group, compared to 4.5% in the control group, RR 1.17, 95% CI 0.79 to 1.74, I2 = 15%; 10 studies; 2640 participants; low-certainty evidence downgraded due to inconsistency and imprecision).  No studies of multicomponent interventions reported data on new diagnoses of dementia.  Multicomponent interventions may result in a small reduction of around a day in the duration of a delirium episode (mean difference (MD) -0.93, 95% CI -2.01 to 0.14 days, I2 = 65%; 351 participants; low-certainty evidence downgraded due to risk of bias and imprecision). The evidence is very uncertain about the effect of multicomponent interventions on delirium severity (standardised mean difference (SMD) -0.49, 95% CI -1.13 to 0.14, I2=64%; 147 participants; very low-certainty evidence downgraded due to risk of bias and serious imprecision). Multicomponent interventions may result in a reduction in hospital length of stay compared to usual care (MD -1.30 days, 95% CI -2.56 to -0.04 days, I2=91%; 3351 participants; low-certainty evidence downgraded due to risk of bias and inconsistency), but little to no difference in new care home admission at the time of hospital discharge (RR 0.77, 95% CI 0.55 to 1.07; 536 participants; low-certainty evidence downgraded due to risk of bias and imprecision). Reporting of other adverse outcomes was limited.  Our exploratory component network meta-analysis found that re-orientation (including use of familiar objects), cognitive stimulation and sleep hygiene were associated with reduced risk of incident delirium. Attention to nutrition and hydration, oxygenation, medication review, assessment of mood and bowel and bladder care were probably associated with a reduction in incident delirium but estimates included the possibility of no benefit or harm.  Reducing sensory deprivation, identification of infection, mobilisation and pain control all had summary estimates that suggested potential increases in delirium incidence, but the uncertainty in the estimates was substantial.  Evidence from two trials suggests that use of a liberal transfusion threshold over a restrictive transfusion threshold probably results in little to no difference in incident delirium (RR 0.92, 95% CI 0.62 to 1.36; I2 = 9%; 294 participants; moderate-certainty evidence downgraded due to risk of bias).  Six other interventions were examined, but evidence for each was limited to single studies and we identified no evidence of delirium prevention.  AUTHORS' CONCLUSIONS: There is moderate-certainty evidence regarding the benefit of multicomponent non-pharmacological interventions for the prevention of delirium in hospitalised adults, estimated to reduce incidence by 43% compared to usual care. We found no evidence of an effect on mortality. There is emerging evidence that these interventions may reduce hospital length of stay, with a trend towards reduced delirium duration, although the effect on delirium severity remains uncertain. Further research should focus on implementation and detailed analysis of the components of the interventions to support more effective, tailored practice recommendations.

Near-Infrared Spectroscopy (NIRS) for Cerebral and Tissue Oximetry: Analysis of Evolving Applications

THE USE OF NEAR-INFRARED SPECTROSCOPY (NIRS) has increased significantly worldwide in the past decade. This technology, first described more than 40 years ago, is based on the fact that near-infrared light is able to penetrate biologic tissue and can obtain real-time, noninvasive information on tissue oxygenation and metabolism. In the clinical setting, NIRS has been able to provide clinicians potentially valuable information in patients with impaired microcirculations (systemic and cerebral). Near-infrared spectroscopy has progressed beyond assessment of brain oxygenation to monitor local tissue and muscle oxygenation and perfusion. This review analyzes the published data and provides the clinician a comprehensive account of the perioperative utility of NIRS in cardiac, vascular and thoracic surgery, as well as its increasing role in tissue/muscle oxygenation monitoring.

Cerebral oximetry and preventing neurological complication post-cardiac surgery: a systematic review

OBJECTIVES

This systematic review aims to provide an up-to-date summary of the current literature examining the relationship between intraoperative regional cerebral oxygen saturation and neurological complications after cardiac surgery.

METHODS

Observational and interventional studies investigating the link between regional cerebral oxygen saturation and postoperative delirium, cognitive dysfunction and stroke were included. After database searching and study screening, study characteristics and major findings were extracted.

RESULTS

Twenty-seven studies were identified. Of the observational studies (n = 17), 8 reported that regional cerebral oxygen desaturations were significantly associated with neurological complications after cardiac surgery. Of the interventional studies (n = 10), 3 provided evidence for monitoring cerebral oximetry during cardiac surgery as a means of reducing incidence of postoperative cognitive dysfunction or stroke. There was significant heterogeneity in the tools and rigor used to diagnose neurological complications.

CONCLUSIONS

Studies to date show an inconsistent relationship between regional cerebral oxygen saturation and neurological outcomes after cardiac surgery, and lack of clear benefit of targeting cerebral oximetry to minimize neurological complications. Standardized assessments, definitions of impairment and desaturation thresholds will help determine the benefits of cerebral oximetry monitoring during cardiac surgery.

Intraoperative cerebral oximetry in open heart surgeries reduced postoperative complications: A retrospective study

Cardiothoracic surgeries are life-saving procedures but often it results in various complications. Intraoperative cerebral oximetry monitoring used to detect regional cerebral oxygen saturation (rScO2) is a non-invasive method that provides prognostic importance in cardiac surgery. The main aim of the present study was to evaluate the association of intraoperative cerebral oxygen monitoring during cardiac surgery on postoperative complications. This was a case-controlled retrospective study conducted on adult patients, who underwent open-heart surgery in National Heart Institute, Malaysia. The case group comprised patients on protocolized cerebral oximetry monitoring. They were treated using a standardized algorithm to maintain rScO2 not lower than 20% of baseline rScO2. The control group comprised patients with matched demographic background, preoperative risk factors, and type of surgical procedures. Propensity score stratification was utilized to contend with selection bias. Retrospective analysis was performed on 240 patients (case group) while comparing it to 407 patients (control group). The non-availability of cerebral oximetry monitoring during surgery was the prominent predictor for all outcome of complications; stroke (OR: 7.66), renal failure needing dialysis (OR: 5.12) and mortality (OR: 20.51). Postoperative complications revealed that there were significant differences for risk of mortality (p<0.001, OR = 20.51), renal failure that required dialysis (p<0.001, OR = 5.12) and stroke (p <0.05, OR = 7.66). Protocolized cerebral oximetry monitoring during cardiothoracic surgeries was found to be associated with lower incidence of stroke, renal failure requiring dialysis and mortality rate.

The role of non-invasive brain oximetry in adult critically ill patients without primary brain injury

A primary objective in intensive care and perioperative settings is to promote an adequate supply and delivery of oxygen to tissues and organs, particularly to the brain. Cerebral near infrared spectroscopy (NIRS) is a non-invasive, continuous monitoring technique, that can be used to assess cerebral oxygenation. Using NIRS to monitor cerebral oximetry is not new, and has been in widespread use in neonates and cardiac surgery for decades. In addition, it has become common to see NIRS being used in adult and pediatric cardiac surgery, acute neurological diseases, neurosurgical procedures, vascular surgery, severe trauma and other acute medical diseases. Furthermore, recent evidence suggests a role for NIRS in the perioperative settings; detecting and preventing episodes of cerebral desaturation aiming to reduce the development of post-operative delirium. NIRS is not without its limitations; these include the risk of extra-cranial contamination, spatial limitations and skin blood flow/volume changes, as well being a measure of localized blood oxygenation underneath the sensor. However, NIRS is a non-invasive technique and can, therefore, be used in those patients without indications or justification for invasive brain monitoring; non-neurosurgical procedures such as liver transplantation, major orthopedic surgery and critically illness where the brain is at risk. The aim of this manuscript was to discuss the physical principles of NIRS and to report the current evidence regarding its use in critically ill patients without primary non-anoxic brain injury.

Association Among Preoperative Cognitive Performance, Regional Cerebral Oxygen Saturation, and Postoperative Delirium in Older Portuguese Patients

BACKGROUND

Postoperative delirium is common among older patients and preoperative identification of high-risk patients is widely recommended. The aim of this study was to assess whether preoperative cognitive performance using brief screening tools or regional cerebral oxygen saturation (Scto2) was associated with the development of postoperative delirium in older Portuguese patients undergoing elective surgery.

METHODS

Prospective observational cohort study where preoperative cognitive screening tools (Mini-Cog, Mini-Mental State Examination, verbal fluency) and Scto2 (INVOS 5100C; Medtronic, Ireland) were assessed in 238 patients ≥65 years old undergoing elective surgery between July 2017 and May 2019 at a tertiary academic center in Portugal. The primary outcome was postoperative delirium detected by the 3D-Confusion Assessment Method. Data were analyzed by univariate analysis and multivariable logistic regression.

RESULTS

Delirium was identified in 53 patients (22%); 162 patients (68%) had completed only 4 years of education. On multivariable analysis, probable cognitive impairment tested by the Mini-Cog (odds ratio [OR] = 1.57; 95% confidence interval [CI], 0.70-3.53; corrected P value >.999), by the Mini-Mental State Examination (OR = 2.75; 95% CI, 1.23-6.13; corrected P value = .052), and by the animal verbal fluency test (OR = 1.24; 95% CI, 0.49-3.16; corrected P value >.999) were not significantly associated with the development of postoperative delirium. In contrast, lower preoperative Scto2 (OR = 1.08; 95% CI, 1.02-1.14; corrected P value = .024 for each point decrease in Scto2) was associated with postoperative delirium.

CONCLUSIONS

We did not find enough evidence to suggest that poor preoperative cognitive performance was significantly associated with the development of postoperative delirium in an older Portuguese surgical population with an overall low level of formal education, but rather that preoperative Scto2 may be helpful in identifying patients at risk for delirium.

Factors associated with delirium after cardiac surgery: A prospective cohort study

Background:

Delirium is a frequent complication after cardiac surgery and is associated with a higher incidence of morbidity and mortality and a prolonged hospital stay. However, knowledge of the variables involved in its occurrence is still limited; therefore, in this study, we evaluated the perioperative risk factors independently associated with this complication.

Methods:

This study was conducted in a referral tertiary care university hospital with a cardiovascular focus. A total of 311 consecutive adult patients undergoing any type of cardiac surgery were evaluated. The subjects were examined at regular intervals in the postoperative period using the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) tool.

Results:

The incidence of postoperative delirium (PD) was 10%. Among the 18 pre-, intra- and postoperative variables evaluated, the logistic regression analysis showed that low education level, history of diabetes or stroke, type of surgery, prolonged extracorporeal circulation, or red blood cell transfusion in the intra- or postoperative period were independently associated with delirium after cardiac surgery. An increased body mass index was identified as a protective factor.

Conclusions:

The aforementioned risk factors are significantly and independently associated with the presentation of PD. Because some of these factors can be treated or avoided, the results of this study are highly relevant to reduce the risk of this complication and improve the care of patients undergoing cardiac surgery.

The relationship between intraoperative cerebral oximetry and postoperative delirium in patients undergoing off-pump coronary artery bypass graft surgery: a retrospective study

Background

Cerebral oximetry has been widely used to measure regional oxygen saturation in brain tissue, especially during cardiac surgery. Despite its popularity, there have been inconsistent results on the use of cerebral oximetry during cardiac surgery, and few studies have evaluated cerebral oximetry during off pump coronary artery bypass graft surgery (OPCAB).

Methods

To evaluate the relationship between intraoperative cerebral oximetry and postoperative delirium in patients who underwent OPCAB, we included 1439 patients who underwent OPCAB between October 2004 and December 2016 and among them, 815 patients with sufficient data on regional cerebral oxygen saturation (rSO₂) were enrolled in this study. We retrospectively analyzed perioperative variables and the reduction in rSO₂ below cut-off values of 75, 70, 65, 60, 55, 50, 45, 40, and 35%. Furthermore, we evaluated the relationship between the reduction in rSO₂ and postoperative delirium.

Results

Delirium occurred in 105 of 815 patients. In both univariable and multivariable analyses, the duration of rSO₂ reduction was significantly longer in patients with delirium at cut-offs of < 50 and 45% (for every 5 min, adjusted odds ratio (OR) 1.007 [95% Confidence interval (CI) 1.001 to 1.014] and adjusted OR 1.012 [1.003 to 1.021]; p = 0.024 and 0.011, respectively). The proportion of patients with a rSO₂ reduction < 45% was significantly higher among those with delirium (adjusted OR 1.737[1.064 to 2.836], p = 0.027).

Conclusions

In patients undergoing OPCAB, intraoperative rSO₂ reduction was associated with postoperative delirium. Duration of rSO₂ less than 50% was 40% longer in the patients with postoperative delirium. The cut-off value of intraoperative rSO₂ that associated with postoperative delirium was 50% for the total patient population and 55% for the patients younger than 68 years.

Supplementary information

Supplementary information accompanies this paper at 10.1186/s12871-020-01180-x.

Effects of electroencephalography and regional cerebral oxygen saturation monitoring on perioperative neurocognitive disorders: a systematic review and meta-analysis

BACKGROUND

Perioperative neurocognitive disorders (PND) is a common postoperative complication including postoperative delirium (POD), postoperative cognitive decline (POCD) or delayed neurocognitive recovery. It is still controversial whether the use of intraoperative cerebral function monitoring can decrease the incidence of PND. The purpose of this study was to evaluate the effects of different cerebral function monitoring (electroencephalography (EEG) and regional cerebral oxygen saturation (rSO2) monitoring) on PND based on the data from randomized controlled trials (RCTs).

METHODS

The electronic databases of Ovid MEDLINE, PubMed, EMBASE, Cochrane Library database were systematically searched using the indicated keywords from their inception to April 2020. The odds ratio (OR) or mean difference (MD) with 95% confidence interval (CI) were employed to analyze the data. Heterogeneity across analyzed studies was assessed with chi-square test and I2 test.

RESULTS

Twenty two RCTs with 6356 patients were included in the final analysis. Data from 12 studies including 4976 patients were analyzed to assess the association between the EEG-guided anesthesia and PND. The results showed that EEG-guided anesthesia could reduce the incidence of POD in patients undergoing non-cardiac surgery (OR: 0.73; 95% CI: 0.57-0.95; P = 0.02), but had no effect on patients undergoing cardiac surgery (OR: 0.44; 95% CI: 0.05-3.54; P = 0.44). The use of intraoperative EEG monitoring reduced the incidence of POCD up to 3 months after the surgery (OR: 0.69; 95% CI: 0.49-0.96; P = 0.03), but the incidence of early POCD remained unaffected (OR: 0.61; 95% CI: 0.35-1.07; P = 0.09). The remaining 10 studies compared the effect of rSO2 monitoring to routine care in a total of 1380 participants on the incidence of PND. The results indicated that intraoperative monitoring of rSO2 could reduce the incidence of POCD (OR 0.53, 95% CI 0.39-0.73; P < 0.0001), whereas no significant difference was found regarding the incidence of POD (OR: 0.74; 95% CI: 0.48-1.14; P = 0.17).

CONCLUSIONS

The findings in the present study indicated that intraoperative use of EEG or/and rSO2 monitor could decrease the risk of PND.

TRIAL REGISTRATION

PROSPREO registration number: CRD42019130512 .

[Near-infrared spectroscopy : Technique, development, current use and perspectives]

Near-infrared spectroscopy (NIRS) has been available in research and clinical practice for more than four decades. Recently, there have been numerous publications and substantial developments in the field. This article describes the clinical application of NIRS in relation to current guidelines, with a focus on pediatric and cardiac anesthesia. It discusses technical and physiological principles, pitfalls in clinical use and presents (patho)physiological influencing factors and derived variables, such as fractional oxygen extraction (FOE) and the cerebral oxygen index (COx). Recommendations for the interpretation of NIRS values in connection with influencing factors, such as oxygen transport capacity, gas exchange and circulation as well as an algorithm for cardiac anesthesia are presented. Limitations of the method and the lack of comparability of values from different devices as well as generally accepted standard values are explained. Technical differences and advantages compared to pulse oxymetry and transcranial Doppler sonography are illuminated. Finally, the prognostic significance and requirements for future clinical studies are discussed.

Pathomechanisms of Non-Traumatic Acute Brain Injury in Critically Ill Patients

Delirium, an acute alteration in mental status characterized by confusion, inattention and a fluctuating level of arousal, is a common problem in critically ill patients. Delirium prolongs hospital stay and is associated with higher mortality. The pathophysiology of delirium has not been fully elucidated. Neuroinflammation and neurotransmitter imbalance seem to be the most important factors for delirium development. In this review, we present the most important pathomechanisms of delirium in critically ill patients, such as neuroinflammation, neurotransmitter imbalance, hypoxia and hyperoxia, tryptophan pathway disorders, and gut microbiota imbalance. A thorough understanding of delirium pathomechanisms is essential for effective prevention and treatment of this underestimated pathology in critically ill patients.

Outcomes of individualized goal-directed therapy based on cerebral oxygen balance in high-risk patients undergoing cardiac surgery: A randomized controlled trial

STUDY OBJECTIVE

To investigate whether optimizing individualized goal-directed therapy (GDT) based on cerebral oxygen balance in high-risk surgical patients would reduce postoperative morbidity.

DESIGN

This was a prospective, randomized, controlled study.

SETTING

The study was performed in the First Affiliated Hospital of Anhui Medical University, Hefei, China, from April 2017 to July 2018.

PATIENTS

146 high-risk adult patients undergoing valve replacements or coronary artery bypass surgery with cardiopulmonary bypass (CPB) were enrolled.

INTERVENTION

Patients were randomized to an individualized GDT group or usual care group. Individualized GDT was targeted to achieve the following goals: A less than 20% decline in the regional cerebral oxygen saturation (rScO₂) level from baseline; a less than 20% decline in the mean arterial pressure (MAP) from baseline, as well as a bispectral index (BIS) of 45-60 before and after CPB and 40-45 during CPB.

MEASUREMENTS

The primary outcome was a composite endpoint of 30-day mortality and major postoperative complications.

MAIN RESULTS

128 completed the trial and were included in the modified intention-to-treat analysis. Early morbidity was similar between the GDT (25 [39%] of 65 patients) and usual care groups (33 [53%] of 63 patients) (relative risk 0.73, 95% CI 0.50-1.08; P = 0.15). Secondary analysis showed that 75 (59%) of 128 patients achieved individual targets (irrespective of intervention) and sustained less morbidity (relative risk 3.41, 95% CI 2.19-5.31; P < 0.001).

CONCLUSIONS

In high-risk patients undergoing cardiac surgery, individualized GDT therapy did not yield better outcomes, however, the achievement of preoperative individual targets may be associated with less morbidity.

TRIAL REGISTRATION

Clinicaltrials.gov identifier: NCT03103633. Registered on 1 April 2017.

The Association of Cerebral Desaturation During One-Lung Ventilation and Postoperative Recovery: A Prospective Observational Cohort Study

OBJECTIVES

This study was designed to investigate whether cerebral oxygen desaturations during thoracic surgery are predictive of patients' quality of recovery. As a secondary aim, the authors investigated the relationship among cerebral desaturations and postoperative delirium and hospital length of stay.

DESIGN

This study was a prospective observational cohort study.

SETTING

A single tertiary-care medical center from September 2012 through March 2014.

PATIENTS

Adult patients scheduled for elective pulmonary surgery requiring one-lung ventilation.

INTERVENTIONS

All patients were monitored with the ForeSight cerebral oximeter.

MEASUREMENTS AND MAIN RESULTS

The primary assessment tool was the Postoperative Quality of Recovery Scale. Delirium was assessed using the Confusion Assessment Method. Of the 117 patients analyzed in the study, 60 of the patients desaturated below a cerebral oximetry level of 65% for a minimum of 3 minutes (51.3%). Patients who desaturated were significantly less likely to have cognitive recovery in the immediate postoperative period (p = 0.012), which did not persist in the postoperative period beyond day 0. Patients who desaturated also were more likely to have delirium (p = 0.048, odds ratio 2.81 [95% CI 1.01-7.79]) and longer length of stay (relative duration 1.35, 95% CI 1.05-1.73; p = 0.020).

CONCLUSIONS

Intraoperative cerebral oxygen desaturations, frequent during one-lung ventilation, are associated significantly with worse early cognitive recovery, high risk of postoperative delirium, and prolonged length of stay. Large interventional studies on cerebral oximetry in the thoracic operating room are warranted.