Predictors of cognitive recovery after cardiac surgery

Neurologic complications after cardiopulmonary bypass - A narrative review

Neurologic complications, associated with cardiac surgery and cardiopulmonary bypass (CPB) in adults, are common and can be devastating in some cases. This comprehensive review will not only consider the broad categories of stroke and neurocognitive dysfunction, but it also summarises other neurological complications associated with CPB, and it provides an update about risks, prevention and treatment. Where appropriate, we consider the impact of off-pump techniques upon our understanding of the contribution of CPB to adverse outcomes.

Efficacy of mobile-based cognitive behavior therapy on lowering low-density lipoprotein cholesterol level in atherosclerotic cardiovascular disease patients: a multicenter, prospective, randomized controlled tria (Preprint)

BACKGROUND

Elevated low-density lipoprotein cholesterol (LDL-C) is an established risk factor for atherosclerotic cardiovascular disease (ASCVD). However, low adherence to medication and lifestyle management has limited the benefits of lowering lipid levels. Cognitive behavioral therapy (CBT) has been proposed as a promising solution.

OBJECTIVE

This trial aimed to evaluate the efficacy of mobile-based CBT interventions in lowering LDL-C levels in patients with ASCVD.

METHODS

This multicenter, prospective, randomized controlled trial enrolled 300 patients with ASCVD, who were randomly assigned to the mobile-based CBT intervention group and the control group in a ratio of 1:1. The intervention group received CBT for ASCVD lifestyle interventions delivered by WeChat MiniApp: "CBT ASCVD." The control group only received routine health education during each follow-up. The linear regression and logistic regression analyses were used to determine the effects of a mobile-based CBT intervention on LDL-C, triglyceride, C-reactive protein, the score of General Self-Efficacy Scale (GSE), quality of life index (QL-index), and LDL-C up-to-standard rate (<1.8 mmol/L) at the first, third, and sixth months.

RESULTS

Finally, 296 participants completed the 6-month follow-up (CBT group: n=148; control group: n=148). At baseline, the mean LDL-C level was 2.48 (SD 0.90) mmol/L, and the LDL-C up-to-standard rate (<1.8 mmol/L) was 21.3%. Mobile-based CBT intervention significantly increased the reduction of LDL-C change (%) at the 6-month follow-up (β=-10.026, 95% CI -18.111 to -1.940). In addition, this benefit remained when baseline LDL-C <1.8 mmol/L (β=-24.103, 95% CI -43.110 to -5.095). Logistic regression analysis showed that mobile-based CBT intervention moderately increased the LDL-C up-to-standard rates (<1.8 mmol/L) in the sixth month (odds ratio 1.579, 95% CI 0.994-2.508). For GSE and QL-index, mobile-based CBT intervention significantly increased the change of scores (%) at the 1-, 3-, and 6-month follow-up (all P values <.05).

CONCLUSIONS

In patients with ASCVD, mobile-based CBT is effective in reducing LDL-C levels (even for those who already had a standard LDL-C) and can improve self-efficacy and quality of life.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR2100046775; https://www.chictr.org.cn/showproj.aspx?proj=127140.

The effect of second-generation antidepressant treatment on the attention and mental processing speed of patients with major depressive disorder: A meta-analysis study with structural equation models

Major depressive disorder (MDD) has been linked to attention and mental processing speed deficits that can be improved after pharmacological treatment. However, it is unclear whether a class of antidepressants is more effective than others to ameliorate these deficits in MDD. Additionally, the possible effects of clinical and demographic variables on improving MDD attention and processing speed deficits after antidepressant treatment are unknown. We aimed to study the possible neuropsychological effects of second-generation antidepressant classes on the attention and processing speed of MDD patients and the potential influences of clinical and demographic variables as moderators of these effects using a meta-analytic approach. Twenty-five papers were included in our study. A structural equation model meta-analysis was performed. The improvement of attention and processing speed after pharmacological treatment is clinically relevant but incomplete. Selective serotonin reuptake inhibitors (SSRIs) and dual inhibitors are the drugs causing the greatest improvement in the processing speed of MDD patients. Antidepressant class is an important variable linked to processing speed improvement after MDD treatment. However, the degree of improvement in both cognitive functions is strongly influenced by some clinical and demographic variables of depressed patients, such are age and education of the MDD patients, the duration of the antidepressant treatment, and the depression status of the patients.

Relationship Between Depression/Anxiety and Cognitive Function Before and 6 Weeks After Major Non-Cardiac Surgery in Older Adults

OBJECTIVE

To determine the relationship between affective measures and cognition before and after non-cardiac surgery in older adults.

METHODS

Observational prospective cohort study in 103 surgical patients age ≥ 60 years old. All participants underwent cognitive testing, Center for Epidemiologic Studies-Depression, and State Anxiety Inventory screening before and 6 weeks after surgery. Cognitive test scores were combined by factor analysis into 4 cognitive domains, whose mean was defined as the continuous cognitive index (CCI). Postoperative global cognitive change was defined by CCI change from before to after surgery, with negative CCI change indicating worsened postoperative global cognition and vice versa.

RESULTS

Lower global cognition before surgery was associated with greater baseline depression severity (Spearman's r = -0.30, p = 0.002) and baseline anxiety severity (Spearman's r = -0.25, p = 0.010), and these associations were similar following surgery (r = -0.36, p < 0.001; r = -0.26, p = 0.008, respectively). Neither baseline depression or anxiety severity, nor postoperative changes in depression or anxiety severity, were associated with pre- to postoperative global cognitive change.

CONCLUSIONS

Greater depression and anxiety severity were each associated with poorer cognitive performance both before and after surgery in older adults. Yet, neither baseline depression or anxiety symptoms, nor postoperative change in these symptoms, were associated with postoperative cognitive change.

Effectiveness of cognitive behavioral therapy-based interventions on health outcomes in patients with coronary heart disease: A meta-analysis

BACKGROUND

Recently, the efficacy of cognitive behavioral therapy (CBT)-based intervention on health outcomes in patients with coronary heart disease (CHD) has been recognized in randomized controlled trials (RCTs), but no comprehensive systematic review has been conducted. To address this research gap, our study aimed to evaluate whether comprehensive CBT-based interventions positively affect health outcomes in CHD patients. It was hypothesized that CBT-based interventions are effective in: (1) Reducing depression, anxiety, and stress symptoms; (2) Reducing body mass index, blood pressure, and lipid levels; and (3) Improving quality of life, and exercise endurance.

AIM

To verify the effectiveness of CBT-based interventions on CHD patients through a meta-analysis of previous publications.

METHODS

Relevant RCTs published in English were obtained by searching electronic databases, including PubMed, Embase, Cochrane Central Register of Controlled Trials, Scopus, and Proquest, with the retrieval time from inception to August 2020. The primary outcomes were psychological factors (depression, anxiety, and stress symptoms), physiological factors (body mass index, blood pressure, blood lipids). The secondary outcomes included quality of life and exercise endurance. We used Review Manager 5.3 to conduct the meta-analysis and used the Physiotherapy Evidence Database tool to evaluate the quality of studies.

RESULTS

A total of 22 RCTs comprising 4991 patients with CHD were included in the systematic review and meta-analysis. The main analysis revealed that CBT-based intervention can reduce depression symptoms: -2.00 [95% confidence interval (CI): -2.83 to -1.16, P < 0.001]; anxiety symptoms: -2.07 (95%CI: -3.39 to -0.75, P = 0.002); stress symptoms: -3.33 (95%CI: -4.23 to -2.44, P < 0.001); body mass index: -0.47 (95%CI: -0.81 to -0.13, P = 0.006); and improve physical functioning: 3.36 (95%CI: 1.63 to 5.10, P = 0.000) and mental functioning: 6.91 (95%CI: 4.10 to 9.73, P < 0.001). Moreover, subgroup analysis results showed that CBT-based interventions were more effective for symptoms of depression and anxiety in CHD patients when individual, as opposed to group treatment, and psycho-education, behavioral and cognitive strategies were applied as the core treatment approaches.

CONCLUSION

CBT-based interventions are effective treatment strategies for CHD patients, significantly improving their symptoms of depression, anxiety and stress, body mass index, and health-related quality of life.

Predictors of cognitive dysfunction after cardiac surgery: a systematic review

AIMS

Postoperative cognitive dysfunction (POCD) is often experienced by cardiac surgery patients; however, it is not known if some groups of patients experience this more frequently or severely than others.The aim of this systematic review was to identify preoperative and postoperative predictors of cognitive dysfunction in adults following cardiac surgery.

METHODS AND RESULTS

Eight bibliographic databases were searched (January 2005 to March 2021) in relation to cardiac surgery and cognition. Studies including adult patients who had undergone open cardiac surgery and using a validated measurement of cognitive function were included. Full-text review for inclusion, quality assessment, and data extraction were undertaken independently by two authors.A total of 2870 papers were identified, of which 36 papers met the inclusion criteria and were included in the review. The majority were prospective observational studies [n = 28 (75.7%)]. In total, 61 independent predictors (45 preoperative and 16 postoperative) were identified as significant in at least one study; advancing age and education level appear important. Age has emerged as the most common predictor of cognitive outcome.

CONCLUSION

Although a number of predictors of POCD have been identified, they have inconsistently been reported as significantly affecting cognitive outcome. Consistent with previous research, our findings indicate that older patients and those with lower educational levels should be prioritized when developing and trialling interventions to improve cognitive function. These findings are less than surprising if we consider the methodological shortcomings of included studies. It is evident that further high-quality research exploring predictors of POCD is required.

Intraoperative Oxygen Concentration and Neurocognition after Cardiac Surgery

BACKGROUND

Despite evidence suggesting detrimental effects of perioperative hyperoxia, hyperoxygenation remains commonplace in cardiac surgery. Hyperoxygenation may increase oxidative damage and neuronal injury leading to potential differences in postoperative neurocognition. Therefore, this study tested the primary hypothesis that intraoperative normoxia, as compared to hyperoxia, reduces postoperative cognitive dysfunction in older patients having cardiac surgery.

METHODS

A randomized double-blind trial was conducted in patients aged 65 yr or older having coronary artery bypass graft surgery with cardiopulmonary bypass. A total of 100 patients were randomized to one of two intraoperative oxygen delivery strategies. Normoxic patients (n = 50) received a minimum fraction of inspired oxygen of 0.35 to maintain a Pao2 above 70 mmHg before and after cardiopulmonary bypass and between 100 and 150 mmHg during cardiopulmonary bypass. Hyperoxic patients (n = 50) received a fraction of inspired oxygen of 1.0 throughout surgery, irrespective of Pao2 levels. The primary outcome was neurocognitive function measured on postoperative day 2 using the Telephonic Montreal Cognitive Assessment. Secondary outcomes included neurocognitive function at 1, 3, and 6 months, as well as postoperative delirium, mortality, and durations of mechanical ventilation, intensive care unit stay, and hospital stay.

RESULTS

The median age was 71 yr (interquartile range, 68 to 75), and the median baseline neurocognitive score was 17 (16 to 19). The median intraoperative Pao2 was 309 (285 to 352) mmHg in the hyperoxia group and 153 (133 to 168) mmHg in the normoxia group (P < 0.001). The median Telephonic Montreal Cognitive Assessment score on postoperative day 2 was 18 (16 to 20) in the hyperoxia group and 18 (14 to 20) in the normoxia group (P = 0.42). Neurocognitive function at 1, 3, and 6 months, as well as secondary outcomes, were not statistically different between groups.

CONCLUSIONS

In this randomized controlled trial, intraoperative normoxia did not reduce postoperative cognitive dysfunction when compared to intraoperative hyperoxia in older patients having cardiac surgery. Although the optimal intraoperative oxygenation strategy remains uncertain, the results indicate that intraoperative hyperoxia does not worsen postoperative cognition after cardiac surgery.

EDITOR’S PERSPECTIVE

THE EFFECT OF SECOND-GENERATION ANTIDEPRESSANT TREATMENT ON THE EXECUTIVE FUNCTIONS OF PATIENTS WITH MAJOR DEPRESSIVE DISORDER: A META-ANALYSIS STUDY WITH STRUCTURAL EQUATION MODELS

Major depressive disorder (MDD) has been linked to executive functions (EF) deficits that can be improved after pharmacological treatment, but it is unclear whether there is a class of antidepressants that is more effective than others to ameliorate these deficits in MDD. Additionally, the possible effects of clinical and demographic variables on the improvement of MDD EF deficits after pharmacological treatment are currently unknown. Our aim was to study the possible neuropsychological effects of second-generation antidepressant classes on the EF of MDD patients and the potential influence of clinical and demographic variables as moderators of these effects through a meta-analytic approach. Twenty-one papers were included in our study. A structural equation model meta-analysis was performed. The improvement of EF after pharmacological treatment is clinically relevant, but it is incomplete. This effect is influenced by age and years of education of the patients. Selective serotonin reuptake inhibitors (SSRIs) and dual inhibitors are the drugs causing the greatest improvement in EF of MDD patients. Antidepressant class is an important variable linked to EF improvement after MDD treatment, but the degree of improvement in these cognitive functions is strongly influenced by some clinical and demographic variables of patients with depression.

[Effects of different postoperative analgesic strategies on postoperative neurocognitive function and quality of recovery in elderly patients undergoing one lung ventilation]

OBJECTIVE

To evaluate the effects of different postoperative analgesic strategies on neurocognitive function and quality of recovery in elderly patients at 7 days after thoracic surgery with one lung ventilation.

METHODS

Ninety elderly patients undergoing video-assisted thoracic surgery were randomized into 3 groups (n=30) to receive postoperative analgesia with thoracic paravertebral block analgesia (TA), epidural analgesia (EA) and intravenous analgesia (GA). Before and at 7 days after the surgery, the patients' cognitive function was assessed using Mini-Mental State Examination (MMSE), and their early recovery at 7 days postoperatively was evaluated using Quality of Recovery-40 items (QoR-40).

RESULTS

The patients in TA and EA groups had significantly higher MMSE scores and lower incidence of postoperative neurocognitive dysfunction (PNCD) than those in GA group without significant difference between the former two groups. At 7 days after the surgery, serum levels of S100-β and MMP-9 were significantly higher in GA group than in TA and EA group, and did not differ significantly between the latter two groups. QoR-40 scores were significantly higher in TA and EA groups than in GA group, and were higher in TA group than in EA group. The chest intubation time and length of hospital stay were significantly shorter in TA and EA groups than in GA group.

CONCLUSIONS

In elderly patients undergoing surgeries with one lung ventilation, general anesthesia combined with either postoperative continuous thoracic paravertebral block or epidural analgesia can significantly improve postoperative neurocognitive function and quality of recovery, but continuous thoracic paravertebral block analgesia can be more advantageous for improving postoperative quality of recovery.

Preoperative Cognitive Impairment and Postoperative Delirium Predict Decline in Activities of Daily Living after Cardiac Surgery-A Prospective, Observational Cohort Study

Cardiac surgery and subsequent treatment in the intensive care unit (ICU) has been shown to be associated with functional decline, especially in elderly patients. Due to the different assessment tools and assessment periods, it remains yet unclear what parameters determine unfavorable outcomes. This study sought to identify risk factors during the entire perioperative period and focused on the decline in activity of daily living (ADL) half a year after cardiac surgery. Follow-ups of 125 patients were available. It was found that in the majority of patients (60%), the mean ADL declined by 4.9 points (95% CI, −6.4 to −3.5; p < 0.000). In the “No decline” -group, the ADL rose by 3.3 points (2.0 to 4.6; p < 0.001). A multiple regression analysis revealed that preoperative cognitive impairment (MMSE ≤ 26; Exp(B) 2.862 (95%CI, 1.192–6.872); p = 0.019) and duration of postoperative delirium ≥ 2 days (Exp(B) 3.534 (1.094–11.411); p = 0.035) was independently associated with ADL decline half a year after the operation and ICU. Of note, preoperative ADL per se was neither associated with baseline cognitive function nor a risk factor for functional decline. We conclude that the preoperative assessment of cognitive function, rather than functional assessments, should be part of risk stratification when planning complex cardiosurgical procedures.

Common neurodegenerative disorders in the perioperative setting: Recommendations for screening from the Society for Perioperative Assessment and Quality Improvement (SPAQI)

Aging is associated with normal and abnormal brain and cognitive changes. Due to the expected increase in older adults requiring surgery, perioperative clinicians will be increasingly encountering patients with neurodegenerative disease. To help perioperative clinicians understand signs of abnormal behaviors that may mark an undiagnosed neurodegenerative disorder and alert additional patient monitoring, The Society for Perioperative Assessment and Quality Improvement (SPAQI) worked with experts in dementia, neuropsychology, geriatric medicine, neurology, and anesthesiology to provide a summary of cognitive and behavioral considerations for patients with common neurodegenerative disorders being evaluated at preoperative centers. Patients with neurodegenerative disorders are at high risk for delirium due to known neurochemical disruptions, medication interactions, associated frailty, or vascular risk profiles presenting risk for repeat strokes. We provide basic information on the expected cognitive changes with aging, most common neurodegenerative disorders, a list of behavioral features and considerations to help differentiate neurodegenerative disorders. Finally, we propose screening recommendations intended for a multidisciplinary team in the perioperative setting.

The Effect of Second-Generation Antidepressant Treatment on the Memory of Patients With Major Depressive Disorder: A Meta-analysis Study With Structural Equation Models

BACKGROUND

Major depressive disorder (MDD) has been linked to episodic memory deficits that may be improved after pharmacological treatment, but it is unclear whether there is a class of antidepressants that is more effective than others to ameliorate these deficits in MDD. In addition, the possible effects of clinical and sociodemographic variables on the improvement of MDD memory deficits after pharmacological treatment are currently unknown. Our aims are to study the possible neuropsychological effects of second-generation antidepressant classes on the episodic memory of MDD patients and to study the potential effects of clinical and demographic variables as moderators of the effects of antidepressants on the memory of depressed patients through a meta-analysis approach.

PROCEDURES

Nine articles were included in our study. A structural equation model meta-analysis was performed.

RESULTS

Our results suggest that selective serotonin reuptake inhibitors and serotonine-noradrenaline reuptake inhibitors would bring about a substantial improvement in the memory of depressed patients, whereas other antidepressant classes would cause rather modest effects. Our results also suggest that clinical and demographic variables play a very important role as mediators of memory improvement after MDD treatment. Thus, a relatively low level of symptom severity, a high degree of clinical improvement, a younger age, and more years of education were positively related to memory improvement after MDD treatment.

CONCLUSIONS

Although antidepressant class is an important variable linked to memory improvement in MDD, overall, the degree of memory amelioration in depression is very closely related to clinical and demographic variables of patients with depression.

Perioperative Continuous Femoral Nerve Block Reduces Postoperative Cognitive Dysfunction of High-Risk Patients with Femoral Neck Fracture: Evidence from a Retrospective Propensity-Matched Study

BACKGROUND Elderly patients often suffer from postoperative cognitive impairment which increases mortality, morbidity, and the economic burden. However, how continuous femoral nerve block (cFNB) influence the incidence of postoperative cognitive dysfunction (POCD) has never been reported. This study tried to explore how cFNB affects the incidence of POCD among low-risk and high-risk patients with femoral neck fractures. MATERIAL AND METHODS We conducted a retrospective propensity score-matched study and allocated matched patients (n=172) with femoral neck fractures into the cFNB group (n=86) and the control group (n=86). Demographical and clinical data were collected and compared, including the visual analog scale (VAS) score, the morphine consumption, and the POCD incidence. Subgroup analysis of high-risk patients (Mini-Cog score ≤2) and low-risk patients (Mini-Cog score ≥3) was also carried out. RESULTS After matching, baseline characteristics of 2 groups were comparable between the 2 groups (all P>0.05). Compared with the control group, the cFNB group had significantly lower visual analog scale (VAS) score and morphine consumption in the postoperative 3 days (P<0.05). For high-risk patients, the Kaplan-Meier survival curve suggested that the incidence of POCD the cFNB group was significantly lower than the control group (P=0.005), without statistical difference for total or low-risk patients (P>0.05). Multivariate Cox hazard regression analysis showed that the adoption of cFNB conferred a protective effect on POCD (HR=0.556, 95% CI 0.316-0.981, P=0.043). CONCLUSIONS For patients undergoing femoral neck fracture surgery, perioperative cFNB administration is useful in decreasing the incidence of POCD, especially for high-risk patients with a Mini-Cog score equal to or less than 2 points.

[Differential diagnosis of neurological conditions in cardiac patients on the first day after cardiac, ascending aortic and aortic arch surgery and repair of internal carotid arteries]

The review is devoted to analysis of current trends in interdisciplinary approach to the differential diagnosis of patients' conditions on the first day after cardiac, ascending aortic and aortic arch surgery and repair of internal carotid arteries (neurological disorders, delirium, cognitive dysfunction, psycho-emotional disorders, postoperative sedation). This approach is valuable to determine the prognosis and timely treatment. The basic concepts reflecting the discussion between neurologists, cardiovascular surgeons, anesthetists, radiation diagnostics specialists and rehabilitators are summarized. The authors concluded that timely and correct differential diagnosis of the states on the first postoperative day using current tests and interdisciplinary approach to the treatment of patients with postoperative impaired consciousness or neurological/psycho-emotional dysfunction can improve their quality of life and efficiency of medical care.

Association of joint replacement surgery with incident dementia diagnosis in German claims data

ABSTRACTBackground:Cognitive decline is an important complication of joint replacement surgeries in senior people.

METHODS

We determined incidence rates of dementia diagnosis following endoprosthetic joint replacement surgery (upper and lower extremities). The observation period covered up to 28 quarters using German claims data comprising 154,604 cases 65 years and older. Effects were controlled for cerebrovascular and vascular risk factors, age, sex, the presence of a diagnosis of delirium, and regular prescription of sedative or analgesic drugs (SAD).

RESULTS

The rate of incident dementia diagnoses in people without joint replacement surgery was 21.34 per 1,000 person years, compared with 80.76 incident cases when joint replacement surgery was conducted during the quarter of the incident dementia diagnosis; rates declined to 21.77 incident cases 7 and more quarters after joint replacement surgery had taken place. This pattern was maintained when controlling for delirium diagnosis and regular prescription of SAD. Among 10,563 patients with at least one joint replacement surgery, patients with a diagnosis of delirium in the quarter of the surgery were at increased risk of a dementia diagnosis compared to patients without such a diagnosis (HR=2.00, p < 0.001).

CONCLUSION

In people surviving the high-risk phase for dementia immediately after surgery, long-term risk of dementia may reach the level of those without surgery. These findings encourage consequent perioperative management to reduce the risk of dementia as well as prospective studies of potentially beneficial effects of joint replacement surgery on mid- to long-term recovery of mobility and cognition in geriatric patients.

Predictors of extubation failure after open-chest cardiac surgery based on routinely collected data. The importance of a shared interprofessional clinical assessment

BACKGROUND

Extubation failure (ExtF) is associated with prolonged hospital length of stay and mortality in adult cardiac surgery patients postoperatively. In this population, ExtF-related variables such as the arterial partial pressure of oxygen to fraction of inspired oxygen ratio (PaO₂/FiO₂), rapid shallow breathing index, cough strength, endotracheal secretions and neurological function have been sparsely researched.

AIM

To identify variables that are predictive of ExtF and related outcomes.

METHOD

Prospective observational longitudinal study. Consecutively presenting patients ( n=205) undergoing open-heart cardiac surgery and admitted to the Cardiosurgical Intensive Care Unit (CICU) were recruited. The clinical data were collected at CICU admission and immediately prior to extubation. ExtF was defined as the need to restart invasive or non-invasive mechanical ventilation while the patient was in the CICU.

RESULTS

The ExtF incidence was 13%. ExtF related significantly to hospital mortality, CICU length of stay and total hospital length of stay. The risk of ExtF decreased significantly, by 93% in patients with good neurological function and by 83% in those with a Rapid Shallow Breathing Index of ≥57 breaths/min per litre. Conversely, ExtF risk increased 27 times when the PaO₂/FiO₂ was <150 and 11 times when it was ≥450. Also, a reassuring PaO₂/FiO₂ value may hide critical pulmonary or extra-pulmonary conditions independent from alveolar function.

CONCLUSION

The decision to extubate patients should be taken after thoroughly discussing and combining the data derived from nursing and medical clinical assessments. Extubation should be delayed until the patient achieves safe respiratory, oxygenation and haemodynamic conditions, and good neurocognitive function.

Associations of dyslipidaemia and lipid-lowering treatment with risk of postoperative cognitive dysfunction: a systematic review and meta-analysis

BACKGROUND

Lipid imbalance is linked to age-related cognitive impairment, but its role in postoperative cognitive dysfunction (POCD) is unknown. Here, we present a systematic review and meta-analysis on dyslipidaemia, lipid-lowering treatment and POCD risk.

METHODS

PubMed, Ovid SP and Cochrane databases were searched for longitudinal studies that reported on associations of any measure of dyslipidaemia and/or lipid-lowering treatment with POCD as relative risks (RRs) or ORs. Fixed-effects inverse variance models were used to combine effects.

RESULTS

Of 205 articles identified in the search, 17 studies on 2725 patients (grand mean age 67 years; mean age range 61-71 years) with follow-up periods of 1 day to 4 years (median 7 days; IQR 1-68 days) were included. Studies focused almost exclusively on hypercholesterolaemia as a measure of dyslipidaemia and on statins as lipid-lowering treatment. Across 12 studies on hypercholesterolaemia, we found no association with POCD risk (RR 0.93; 95% CI 0.80 to 1.08; P=0.34). Statin use before surgery was associated with a reduced POCD risk across eight studies (RR 0.81; 95% CI 0.67 to 0.98; P=0.03), but data on treatment duration were lacking.

CONCLUSION

Statin users appear to be at reduced risk of POCD although hypercholesterolaemia per se may not be associated with POCD risk. Trial studies are needed to evaluate the usefulness of statins in POCD prevention.

Cerebral perfusion monitoring in adult patients following cardiac surgery: an observational study

BACKGROUND

Following adult cardiac surgery, often difficult to detect fluctuations in regional cerebral perfusion can contribute to strokes. Optimal cerebral perfusion remains elusive and traditional monitoring strategies do not consistently identify acute changes. Non-invasive cerebral oximetry may detect perfusion variations.

OBJECTIVE

To assess the feasibility of postoperative non-invasive cerebral oximetry monitoring.

METHODS

Non-invasive cerebral oximetry was performed on adult aortic valve surgery patients in a cardiac surgical intensive care unit. Monitoring feasibility was assessed using an investigator-developed, data extraction tool.

RESULTS

Non-invasive cerebral oximetry was completed in 94% of patients. Sixty percent had values that fell below pre-set ischemic threshold. Nurses reported monitoring was feasible, and they perceived identifying deleterious cerebral perfusion trends may improve patient care.

CONCLUSIONS

Prevalence of low cerebral oximetry values underscores the importance of increasing sensitivity of monitoring tools. Further evaluation is required to assess this modality and the role of nurses in optimizing neurocognitive outcomes. Impact statement: Cerebral oximetry monitoring may help identify adult patients at risk of neurological complications after cardiac surgery, and as a consequence initiate definitive therapeutic strategies.

Hypertension and Risk of Post-Operative Cognitive Dysfunction (POCD): A Systematic Review and Meta-Analysis

Background:

Post-operative cognitive dysfunction (POCD) occurs frequently after major surgery. Hypertension is well-established as a risk factor for age-related cognitive impairment, but it is unclear whether or not it also increases the risk of POCD.

Objective:

To evaluate the role of hypertension in POCD risk in a systematic review and meta-analysis.

Method:

PubMed, Ovid SP and the Cochrane Database of Systematic Reviews were searched for longitudinal studies of adults undergoing surgery with reporting of hypertension, blood pressure and/or anti-hypertensive treatment associations with POCD as relative risks or odds ratios. Fixed-effects meta-analyses were performed using Review Manager (version 5.3).

Results:

Twenty-four studies on 4317 patients (mean age 63 years) were included. None of the studies had set out to assess hypertension as a risk factor for POCD. Hypertension was used as a categorical predictor throughout and only 2 studies adjusted for potential confounders. Across all 24 studies, hypertension was not significantly associated with POCD risk (RR 1.01; 95% CI 0.93, 1.09; p=0.82), though among 8 studies with >75% males, we found hypertension associations with a 27% increased risk of POCD (RR 1.27, 95% CI 1.07, 1.49; p=0.005).

Conclusion:

Our findings do not support the hypothesis that hypertension is a risk factor for POCD. However, since none of the studies included in our analysis were hypothesis-driven and most did not adjust for potential confounders, further systematic investigations are needed to evaluate the role of hypertension in the epidemiology of POCD.

[Correction of postoperative cognitive dysfunction in cardiosurgery using computer-based stimulation programs]

AIM

To evaluate the efficacy of computer-based stimulation programs in the correction of postoperative cognitive dysfunction in patients with ischemic heart disease in remote period after coronary artery bypass surgery.

MATERIAL AND METHODS

The study involved 74 patients. All patients underwent a drug therapy and the rehabilitation course using computer-based stimulation programs (1 time per day for 20 minutes during10 days). Coronary artery bypass surgery was performed for all patients. Patients were examined before operation, after 6 and 12 months.

RESULTS

The significant improvement of higher cortical functions assessed with the FAB scale, the Schulte test, associated thinking test, ten-word retrieval test at the first attempt, the Clock drawing test) was revealed in the group using computer-based stimulation programs in comparison with the control group.

CONCLUSION

It is found that rehabilitation course using computer-based stimulation programs in patients with ischemic heart disease after coronary artery bypass surgery is the effective method of cognitive function correction.

[Cognitive dysfunction after coronary artery bypass grafting]

Despite the advances in surgical and anesthetic techniques for coronary artery bypass grafting (CABG), the incidence of neurological complications, including postoperative cognitive dysfunction (POCD), remains high. CABG is performed more often in elderly patients with severe comorbidities. However, comprehensive prevention measures and POCD rehabilitation have not yet been developed. Physical training is an effective and safe method for correcting endothelial dysfunction, severe systemic inflammatory response syndrome, lipid peroxidation, i.e. mechanisms contributing to the development and severity of POCD.

The effectiveness of the correction of cognitive impairment using computer-based stimulation programs for patients with coronary heart disease after coronary bypass surgery

We evaluated effectiveness of using copyrighted computer-based stimulation programs in the correction of cognitive function in patients with coronary heart disease after coronary bypass surgery.A total of 74 patients were examined, all the patients underwent a course of drug therapy, 37 patients underwent a course of rehabilitation in addition to medical therapy using computer-based stimulation programs (1 time per day for 20 min within 10 days). A course of rehabilitation using computer-based stimulation programs in patients with coronary heart disease after coronary bypass surgery was proved to be an effective way of correcting cognitive function.

Postoperative Cognitive Dysfunction: Minding the Gaps in Our Knowledge of a Common Postoperative Complication in the Elderly

Postoperative cognitive dysfunction (POCD) is a common complication associated with significant morbidity and mortality in elderly patients. There is much interest in and controversy about POCD, reflected partly in the increasing number of articles published on POCD recently. Recent work suggests surgery may also be associated with cognitive improvement in some patients, termed postoperative cognitive improvement (POCI). As the number of surgeries performed worldwide approaches 250 million per year, optimizing postoperative cognitive function and preventing/treating POCD are major public health issues. In this article, we review the literature on POCD and POCI, and discuss current research challenges in this area.

Apolipoprotein epsilon 4 genotype is associated with less improvement in cognitive function five years after cardiac surgery: a retrospective cohort study

PURPOSE

Cognitive performance after cardiac surgery can be impaired, and genetic risk factors have previously been suggested. When compared with other isoforms of the gene, the apolipoprotein epsilon 4 (APOE4) allele is associated with worse outcomes in many neurologic disorders. We hypothesized that the APOE4 allele is associated with less favourable cognitive function five years after surgery.

METHODS

Caucasian patients enrolled in previously reported prospective cognitive trials in both cardiac and non-cardiac surgery participated in this retrospective cohort study. Neuropsychological function was assessed at baseline and five years postoperatively. The relationship between change in cognitive index score and APOE was evaluated using multivariable linear regression. An additive genetic model toward the epsilon 4 allele was applied with adjustment for baseline cognition, years of education, age, presence of diabetes in both cohorts, and presence of coronary artery disease in the non-cardiac surgery cohort.

RESULTS

A total of 357 patients were included in this study. In the cardiac surgery group (n = 233), baseline cognitive index (P < 0.001), years of education (P = 0.04), age at time of surgery (P < 0.001), and the APOE4 allele (P = 0.009), were associated with a five-year change in cognitive index. Patients carrying the APOE4 allele showed less improvement in cognitive index scores five years after cardiac surgery compared with patients without the APOE4 allele. In the non-cardiac surgery (n = 124) group, no association was found between APOE4 allele status and change in cognitive index.

CONCLUSION

We report an association between APOE4 and neurocognitive function five years following cardiac surgery. Preoperative identification of patients with the APOE4 genotype may improve stratification of cardiac surgery patients at risk for a less favourable cognitive trajectory.

Neurological complications of cardiac surgery

As increasing numbers of elderly people undergo cardiac surgery, neurologists are frequently called upon to assess patients with neurological complications from the procedure. Some complications mandate acute intervention, whereas others need longer term observation and management. A large amount of published literature exists about these complications and guidance on best practice is constantly changing. Similarly, despite technological advances in surgical intervention and modifications in surgical technique to make cardiac procedures safer, these advances often create new avenues for neurological injury. Accordingly, rapid and precise neurological assessment and therapeutic intervention rests on a solid understanding of the evidence base and procedural variables.

Cardiac surgery, the brain, and inflammation

Cognitive deterioration can reliably be measured after procedures requiring anesthesia and surgery. Cardiac surgery has had the spotlight because of the high reported incidence of postoperative cognitive dysfunction in early studies, but such effects occur after other surgical procedures as well. "Early" postoperative cognitive dysfunction should be considered as a different phenomenon, relating to acute pharmacological, physiological, and stress-related recovery. The focus should be on what is affecting patients at 3 months, 12 months, and 5 years later. Like with many other aspects of perioperative risk, a significant element is the patient's preoperative cognitive status. We now know that up to one-third of overtly "normal" elective cardiac surgical patients enter surgery with some degree of pre-existing cognitive impairment or, when applying psychogeriatric measures, mild cognitive impairment. The latter is a known prodrome or early stage of the amyloid associated Alzheimer's disease dementia. Inflammatory responses during cardiac surgery have been recognized for years, but our understanding of the complexity of systemic inflammatory response has grown significantly with the ability to assay neurohumoral markers such as interleukins. The blood-brain barrier is made vulnerable by both pre-existing disorders (mild cognitive impairment/amyloid; vascular disease) and by the inflammatory response to surgery and cardiopulmonary bypass. Inflammation affecting the brain at this time may set in motion accelerated neurological and hence cognitive decline that, despite an initial recovery and even functional improvement, may proceed to further long-term decline at an accelerated rate in susceptible individuals. Clinical data are emerging from longer-term studies to support this concern, but evidence for effective preventive or therapeutic strategies is limited.