Outcomes associated with postoperative cognitive dysfunction: a systematic review and meta-analysis.

BACKGROUND: Postoperative cognitive dysfunction (POCD) manifests as a subtle decline in cognition, potentially leading to unfavourable postoperative outcomes. We explored the impact of POCD on physical function, length of hospital stay (LOS), dementia and mortality outcomes. METHODS: PubMed and Scopus were searched until May 2023. All studies of major surgical patients that assessed POCD and outcomes of interest were included. POCD effects were stratified by surgery type (cardiac and noncardiac) and time of POCD assessment (<30 and ≥30 days postsurgery). RESULTS: Of 2316 studies, 20 met the inclusion criteria. POCD was not associated with functional decline postsurgery. Patients who experienced POCD postcardiac surgery had an increased relative risk (RR) of death of 2.04 [(95% CI: 1.18, 3.50); I2 = 0.00%]. Sensitivity analyses showed associations with intermediate-term mortality among noncardiac surgical patients, with an RR of 1.84 [(95% CI: 1.26, 2.71); I2 = 0.00%]. Patients who developed POCD <30 days postcardiac and noncardiac surgeries experienced longer LOS than those who did not [mean difference (MD) = 1.37 days (95% CI: 0.35, 2.39); I2 = 92.38% and MD = 1.94 days (95% CI: 0.48, 3.40); I2 = 83.29%, respectively]. Postoperative delirium (POD) may contribute to the heterogeneity observed, but limited data were reported within the studies included. CONCLUSIONS: Patients undergoing cardiac and noncardiac surgeries who developed POCD <30 days postsurgery had poorer outcomes and an increased risk of premature death. Early recognition of perioperative neurocognitive disorders in at-risk patients may enable early intervention. However, POD may confound our findings, with further studies necessary to disentangle the effects of POD from POCD on clinical outcomes.

Influence of Neostigmine on Early Postoperative Cognitive Dysfunction in Older Adult Patients Undergoing Noncardiac Surgery: A Double-Blind, Placebo-Controlled, Randomized Controlled Trial.

BACKGROUND: The goal of this study was to investigate the efficacy of neostigmine on postoperative cognitive dysfunction (POCD) and determine its effect on systematic markers of oxidative stress in older patients. METHODS: This double-blind placebo-controlled trial enrolled 118 elderly patients (≥65 years) undergoing noncardiac surgeries who were allocated to a neostigmine treatment group (0.04 mg/kg) or a placebo control group (normal saline) postoperatively. POCD was diagnosed if the Z -scores for the mini-mental state examination and the Montreal Cognitive Assessment were both ≤-1.96. Postoperative serum levels of malondialdehyde (MDA), superoxide dismutase (SOD), and brain-derived neurotrophic factor (BDNF) were also compared. Multivariable regression analysis with dose adjustment of atropine was used to demonstrate the influence of neostigmine on the incidence of POCD. RESULTS: Patients receiving neostigmine had a significantly reduced incidence of POCD compared to patients who were treated with placebo on the first day after surgery (-22%, 95% confidence interval [CI], -37 to -7), but not on the third (8%, 95% CI, -4 to 20) or seventh day after surgery (3%, 95% CI, -7 to 13). Postoperative plasma MDA levels were significantly lower ( P = .016), but SOD and BDNF levels were increased ( P = .036 and .013, respectively) in the neostigmine group compared to the control group on the first day after surgery. CONCLUSIONS: Neostigmine reduced POCD on the first day after noncardiac surgery in older patients. Neostigmine treatment inhibited oxidative stress and increased serum BDNF levels. There was no significant influence of neostigmine on POCD on the third or seventh day after surgery. The clinical influence of neostigmine on POCD should be further investigated.

Early postoperative neurocognitive complications in elderly patients: comparing those with and without preexisting mild cognitive impairment- a prospective study.

BACKGROUND: As societies age, increasing numbers of older adults undergo surgeries with anesthesia. Postoperative delirium (POD) and postoperative cognitive dysfunction (POCD) frequently occur in older surgical patients. Most of these patients already have preoperative mild cognitive impairment (MCI). However, the correlation between MCI and POD remains unclear. This study aimed to determine the incidence of POD in elderly patients with and without preexisting MCI. METHODS: A prospective study enrolled patients aged 60 years and above scheduled for major surgeries between December 2017 and April 2022. Preoperative MCI was determined by a Montreal Cognitive Assessment (MoCA) score between 18 and 24. POD was diagnosed using criteria from the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). POCD was characterized by a MoCA score reduction of 2 or more points from the preoperative score. The primary outcome was the incidence of POD within the first 72 h postoperatively. Secondary outcomes encompassed other postoperative complications, including POCD. RESULTS: The study comprised 223 elderly patients with MCI and 56 without MCI. The incidence of POD was 16.6% in the MCI group and 14.3% in the non-MCI group (P = 0.839). POCD occurred in 24.3% of MCI patients and 50% of non-MCI patients (P = 0.001). There were no significant differences in other postoperative complications between the groups. Postoperatively, the MCI group notably declined in visuospatial, attention, and orientation domains, while the non-MCI group declined in all domains except delayed recall. CONCLUSIONS: The incidence of POD was similar in the MCI and non-MCI groups. However, the non-MCI group demonstrated a higher incidence of POCD than the MCI group. This was identified by a reduction in postoperative MoCA scores for the visuospatial, naming, attention, language, abstraction, and orientation domains. These findings underscore the importance of postoperative cognitive assessments for both elderly patients with preexisting MCI and those with previously intact cognitive functions. TRIAL REGISTRATION: This trial was retrospectively registered in the Thai Clinical Trials Registry on 15/01/2019 (registration number: TCTR20190115001).

Identifying postoperative cognitive dysfunction after elective coronary artery bypass graft surgery in a tertiary centre in Malaysia.

Postoperative cognitive dysfunction (POCD) is a significant concern, with incidences reported up to 70% following cardiac surgery. Therefore, we aim to evaluate the incidence of POCD after elective coronary artery bypass graft (CABG) surgery at our single centre over a one-year period from August 2021 to July 2022. We included 34 patients in the study and conducted serial cognitive assessments up to three months post-surgery. Interestingly, our findings indicated an absence of POCD among patients who underwent elective CABG. Reasons contributing to this outcome are multifactorial, which may include the patients' younger age, higher educational levels, lack of pre-existing neurological disorders, meticulous intraoperative cerebral saturation monitoring, and the duration of aortic crossclamp and cardiopulmonary bypass time.

Serum proteomics study on cognitive impairment after cardiac valve replacement surgery: a prospective observational study.

Objective: The incidence of perioperative neurocognitive disorders (PND) is high, especially after cardiac surgeries, and the underlying mechanisms remain elusive. Here, we conducted a prospective observational study to observe serum proteomics differences in PND patients after cardiac valve replacement surgery. Methods: Two hundred and twenty-six patients who underwent cardiac valve surgery were included. They were categorized based on scoring into non-PND group (group non-P) and PND group (group P'). The risk factors associated with PND were analyzed. These patients were further divided into group C and group P by propensity score matching (PSM) to investigate the serum proteome related to the PND by serum proteomics. Results: The postoperative 6-week incidence of PND was 16.8%. Risk factors for PND include age, chronic illness, sufentanil dosage, and time of cardiopulmonary bypass (CPB). Proteomics identified 31 down-regulated proteins and six up-regulated proteins. Finally, GSTO1, IDH1, CAT, and PFN1 were found to be associated with PND. Conclusion: The occurrence of PND can impact some oxidative stress proteins. This study provided data for future studies about PND to general anaesthesia and surgeries.

Maior risco de delirium no pós-operatório está associado à idade avançada, anemia e baixa reserva cognitiva / Greater risk of postoperative delirium is associated with advanced age, anemia, and low cognitive reserve

INTRODUÇÃO: Delirium é uma mudança aguda na cognição e atenção, comum no período pós-operatório em pessoas idosas, associada ao aumento de custos e à permanência hospitalar. OBJETIVO: Avaliar frequência, fatores de risco e influência no período de permanência hospitalar de delirium pós-operatório em pacientes idosos submetidos a cirurgias não cardíacas eletivas. MÉTODO: Estudo do tipo transversal, observacional, de pessoas idosas (65 anos de idade ou mais), internadas para realização de cirurgia eletiva não cardíaca. Durante o período pré-operatório imediato (24 horas) foram avaliados os fatores de risco: idade, gênero, cognição (MiniCog), funcionalidade (Katz e time up and go), fármacos e aspectos clínicos. O delirium, no pós-operatório imediato (até 72 horas), foi avaliado através do Confusion Assesment Method (CAM). RESULTADOS: Oitenta e três pacientes foram incluídos na pesquisa, sendo 44,6% (n = 37) de cirurgia ortopédica, 42,16% (n = 35) de cirurgia geral e 13,3% (n = 11) de cirurgia urológica. Predominou o sexo masculino (53%), com idade média de 73 anos (65 a 94) anos. Na amostra de pacientes, 9,6% (n = 8) apresentaram delirium pós-operatório: 6% do tipo hiperativo (n = 5), 2,4% do tipo hipoativo (n = 2) e 1,2% do tipo misto (n = 1). Eram mais idosos (p = 0,02), com maior declínio cognitivo (p = 0,01), anemia (p = 0,04) e prolongamento na permanência hospitalar (p = 0,001). CONCLUSÃO: O delirium pós-operatório foi observado com maior frequência nos pacientes mais idosos, portadores de declínio cognitivo e anemia, com influência no período de hospitalização, demonstrando a importância de uma avaliação preventiva mais abrangente no período pré-operatório.

INTRODUCTION: Delirium is an acute change in cognition and attention, common in the postoperative period in older patients, associated with increased costs and longer hospital stay. OBJECTIVE: To evaluate the frequency, risk factors, and influence of postoperative delirium in older patients submitted to elective noncardiac surgery. METHOD: This was a cross-sectional, observational study of older adults (65 years or older) hospitalized for elective noncardiac surgery. During the immediate preoperative period (24 hours), risk factors such as age, sex, cognition (MiniCog), functional status (Katz and Timed Up and Go), medications, and clinical aspects were evaluated. Delirium, in the immediate postoperative period (up to 72 hours), was evaluated using the Confusion Assessment Method (CAM). RESULTS: A total of 83 patients were included in the study. Of these, 44.6% (n = 37) had undergone orthopedic surgery, 42.16% (n = 35), general surgery, and 13.3% (n = 11), urological surgery. Most participants were men (53%), with a mean age of 73 (65­94) years. Overall, 9.6% (n = 8) had postoperative delirium: 6% of the hyperactive subtype (n = 5), 2.4% of the hypoactive subtype (n = 2), and 1.2% of the mixed subtype (n = 1). These patients were older (p = 0.02), had greater cognitive decline (p = 0.01), anemia (p = 0.04), and prolonged hospital stay (p = 0.001). CONCLUSION: Postoperative delirium was more commonly observed in the older old with cognitive decline and anemia, with an impact on hospital length of stay, highlighting the importance of a more comprehensive preventive evaluation in the preoperative period.