The Role of Perioperative Sleep Disturbance in Postoperative Neurocognitive Disorders

Trends and Emerging Research Areas in Postoperative Sleep Disturbances: A Bibliometric Analysis

Purpose

Postoperative sleep disturbance (PSD) is highly prevalent and significantly affects patient prognosis. Studies on PSD have received increasing attention, resulting in a surge in related publications. However, comprehensive analyses that can objectively reflect changes in scientific knowledge and identify the latest research trends in this field are lacking.

Methods

Articles and reviews focusing on PSD were extracted from the Web of Science Core Collection database. Bibliometrix, VOSviewer, and CiteSpace were used to conduct bibliometric analysis and map the visualization network.

Results

A total of 1,559 publications were extracted from the database, including 1,370 articles and 189 reviews. There has been a consistent increase in the number of publications, with an average annual growth rate of 16.56%, led by the United States in terms of research output. Notably, the University of Toronto was a prominent contributor. Co-cited reference network analysis revealed 17 well-structured networks (Q = 0.8174, S = 0.9441). Six major research trends were identified: mechanisms of sleep related to anesthesia, role of melatonin in sleep disturbances, pain management strategies, effects of analgesic drugs, impact of dexmedetomidine on sleep quality, and postoperative recovery. Keywords analysis highlighted the emerging roles of dexmedetomidine, neuroinflammation, and acupuncture.

Conclusion

Bibliometric analysis provides a helpful summary of postoperative sleep disturbances that have changed over time, by identifying knowledge points and developing trends. Future research should focus on integrating multidisciplinary approaches, exploring neuroinflammation, evaluating non-pharmacological interventions and long-term outcomes, which will advance scientific knowledge, enhance clinical practice, and improve patient outcomes and quality of life.

A Randomized Clinical Trial of Dexmedetomidine on Delirium, Cognitive Dysfunction, and Sleep After Non-Ambulatory Orthopedic Surgery With Regional Anesthesia

BACKGROUND

Postoperative delirium (POD), emergence delirium (ED), and postoperative cognitive dysfunction (POCD) are disorders of the neuropsychiatric spectrum affecting the elderly during the postoperative period, potentially sharing a common pathophysiological pathway. Disrupted sleep postoperatively correlates with both POD and POCD, revealing overlapping risk factors. This study investigates the potential of dexmedetomidine anesthesia to reduce the incidence of POD (primary outcome), ED, POCD, impairment of sleep quality, and emergent chronic pain (secondary outcomes) in older adults undergoing major orthopedic surgery under regional anesthesia.

METHODS

In this double-blind randomized control trial, patients scheduled for major lower limb orthopedic surgery under regional anesthesia were randomized to receive either dexmedetomidine or propofol for sedation at a 1:1 ratio. POD, ED, and POCD were assessed with the Confusion Assessment Method tool, the Riker Sedation-Agitation scale, and the European Battery of psychometric tests, respectively. Sleep quality was assessed using the Pittsburg Sleep Quality Index and chronic pain with the painDETECT tool. Assessments of all outcome variables were performed before surgery, and at 48 hours and 3 months postoperatively.

RESULTS

A total of 80 patients (dexmedetomidine group n = 41) were enrolled in the study and completed the follow-up. POD, ED, and early POCD incidence were significantly lower in dexmedetomidine compared to propofol group (4.8% vs 38.4%, P = .001; 2.4% vs 38.4%, P < .001; 2.4% vs 56.4%, P < .001, respectively). Patients in the dexmedetomidine group reported improved sleep quality in the immediate postoperative period (lower PSQI score) and lower painDETECT scores at 3 months (4.4 ± 0.7 vs 13.4 ± 0.8, P < .001; 2.4 ± 0.9 vs 5.3 ± 0.9, P = .023, respectively). Intraoperative bradycardia and hemodynamic instability episodes were more common in the dexmedetomidine group while a single patient presented airway obstruction (2.4% vs 30.8%, P = .002) in the dexmedetomidine group.

CONCLUSIONS

Sedation with dexmedetomidine resulted in a statistically and clinically important reduction in the incidence of POD, ED, and early POCD, while it improved self-reported postoperative sleep quality and reduced chronic pain scores in patients undergoing major elective lower limb surgery under regional anesthesia.

Exploring the nexus: Sleep disorders, circadian dysregulation, and Alzheimer's disease

We reviewed the connections among Alzheimer's disease (AD), sleep deprivation, and circadian rhythm disorders. Evidence is mounting that disrupted sleep and abnormal circadian rhythms are not merely symptoms of AD, but are also involved in accelerating the disease. Amyloid-beta (Aβ) accumulates, a feature of AD, and worsens with sleep deprivation because glymphatic withdrawal is required to clear toxic proteins from the brain. In addition, disturbances in circadian rhythm can contribute to the induction of neuroinflammation and oxidative stress, thereby accelerating neurodegenerative processes. While these interactions are bidirectional, Alzheimer's pathology further disrupts sleep and circadian function in a vicious cycle that worsens cognitive decline, which is emphasized in the review. The evidence that targeting sleep and circadian mechanisms may serve as therapeutic strategies for AD was strengthened by this study through the analysis of the molecular and physiological pathways. Further work on this nexus could help unravel the neurobiological mechanisms common to the onset of Alzheimer's and disrupted sleep and circadian regulation, which could result in earlier intervention to slow or prevent the onset of the disease.

Oxidative Stress-mediated Loss of Hippocampal Parvalbumin Interneurons Contributes to Memory Precision Decline After Acute Sleep Deprivation

Sleep is pivotal to memory consolidation, and sleep deprivation (SD) after learning can impede this process, leading to memory disorders. In the present study, we aimed to explore the effects of acute sleep deprivation (ASD) on memory disorders and the underlying mechanisms. ASD model was induced by subjecting the mice to 6 h of SD following fear conditioning training. Different cohorts were used for behavioral, biochemical, and electrophysiological tests. Here, we showed that memory precision decline was induced by ASD, concomitant with a notable elevation in oxidative stress within PV interneurons, loss of PV, and disturbed neuronal oscillation in the CA1 region. Notably, chemogenetic activation of PV interneurons effectively ameliorated abnormal gamma oscillation and memory precision decline observed in ASD mice. Meanwhile, chemogenetic inhibition of PV interneurons successfully mimicked the abnormal brain oscillations and memory precision decline observed in ASD mice. Additionally, prior administration of the antioxidant medication N-acetylcysteine effectively reversed memory precision decline and mitigated PV loss and abnormal oscillation triggered by ASD. Collectively, our findings indicated that ASD increased oxidative stress in PV interneurons, thereby disrupting neural oscillation in the CA1 and ultimately leading to memory precision decline.

Dynamic changes in peripheral inflammation as a risk factor for perioperative sleep disturbances in elderly patients undergoing laparoscopic hepatobiliary surgery

Background

Elderly surgical patients are at high risk of perioperative sleep disturbances (PSD), and the underlying pathogenic mechanisms remain unclear. The relationship between peripheral inflammatory status and PSD pathogenesis currently lacks substantial clinical evidence.

Objective

This study aims to evaluate the association between peripheral inflammation indicators and PSD in elderly patients undergoing laparoscopic hepatobiliary surgery, and to analyze the dynamic changes in peripheral inflammation in PSD patients throughout the perioperative period.

Method and materials

Using retrospective data, this study compares peripheral inflammatory markers (NLR, MLR, PLR, SII, IL-6, and IL-10) in patients with PSD vs. those with normal sleep patterns before and after surgery. Receiver operating characteristic (ROC) curves were employed to evaluate the discriminative power of these indicators for PSD. Logistic regression models were employed to assess risk associations between inflammatory markers and PSD. Dynamic changes in peripheral inflammation were compared before surgery, on the day the surgery ended, and 1 day post-surgery between patients with PSD and those with normal sleep, exploring potential correlations with PSD pathogenesis.

Result

The study ultimately included clinical data from 156 patients. Findings indicated that elevated NLR and SII levels before and after surgery, alongside decreased plasma IL-10 levels post-surgery, are associated with a higher incidence of PSD. Peripheral inflammatory markers on the day of surgery were not significantly predictive of post-PSD. Multivariable logistic regression analyses identified NLR, SII, IL-6, and IL-10 as independent predictors of pre-PSD, while NLR, SII, and IL-10 remained independently associated with post-PSD.

Conclusion

Dynamic changes in peripheral inflammation during the perioperative period are associated with PSD in elderly patients undergoing laparoscopic hepatobiliary surgery. These findings may support the early identification and screening of high-risk PSD patients, providing new insights into the underlying mechanisms of PSD pathogenesis.

Effects of the subanesthetic dose of esketamine on postoperative sleep quality in patients undergoing modified radical mastectomy: a randomized, double-blind controlled trial

Background

Breast cancer is the most common malignant tumor among women worldwide. Surgical intervention is a critical component of treatment, yet the associated stress and anxiety can significantly disrupt postoperative sleep quality. Emerging evidences suggest that esketamine may offer benefits in alleviating emotional distress and enhancing sleep. The purpose of this study was to observe the effects of intraoperative subanesthetic dose of esketamine on the sleep of patients undergoing modified radical mastectomy.

Methods

This randomized, double-blind, controlled trial enrolled 145 female patients, who were randomly assigned to either the esketamine group (Group E, n = 72) or the control group (Group C, n = 73). Patients in Group E received esketamine (0.2 mg/kg loading dose, followed by 0.1 mg/kg/h infusion), while those in Group C received saline (0.2 mL/kg loading dose, followed by 0.1 mL/kg/h infusion). The primary outcome was the total score on the Richards-Campbell Sleep Questionnaire (RCSQ) measured on postoperative day (POD) 1. Secondary outcomes included recovery time, the incidence of postoperative adverse events and rescue analgesia, Visual Analogue Scale (VAS) pain scores, short-form McGill's Pain Questionnaire (SF-MPQ) sensory and affective scores, and Pittsburgh Sleep Quality Index (PSQI) scores.

Results

No significant differences were observed in the total RCSQ scores on POD 1 between Group E and Group C (median [interquartile range]: 46 [32-68] vs. 54 [40-71], p > 0.05). Recovery time was significantly longer in Group E compared to Group C (8 [5-11] vs. 6 [4-11] minutes; p = 0.02). There were no significant differences in the incidence of adverse events or remedial analgesia within 48 h postoperatively. Furthermore, no significant differences were observed between the groups in pain VAS scores, and SF-MPQ sensory or affective scores at 4, 24, and 48 h postoperatively. PSQI scores on POD 30 were not significantly different between the groups (p > 0.05).

Conclusion

For female patients without pre-existing sleep disorders undergoing modified radical mastectomy, intraoperative subanesthetic esketamine may not significantly impact postoperative sleep quality but potentially contribute to a prolonged recovery time.

Trial registration

This trial was registered at the Chinese Clinical Trial Registry on July 03, 2022 (https://www.chictr.org.cn; Registration number: ChiCTR2200061818).

Effect of stellate ganglion block on delirium after major surgery in elderly patients: protocol for a randomised controlled study

INTRODUCTION

Postoperative delirium (POD) remains a prevalent neurological complication among elderly patients following major surgeries, with limited effective preventive measures currently available. Stellate ganglion block (SGB) is widely employed in clinical practices to manage various conditions by modulating the sympathetic nervous system activity. However, there is currently a lack of clinical evidence assessing its effect on the incidence of POD. This study aims to evaluate the safety and efficacy of SGB as a preventive strategy for POD in elderly patients undergoing major surgeries.

METHODS AND ANALYSIS

This randomised controlled clinical trial will be conducted at two centres, enrolling a total of 300 elderly patients aged 65 years and older who are scheduled for elective major surgery. Participants will be randomly assigned to either the SGB group (n=150) or the control group (n=150). In the SGB group, participants will receive an ultrasound-guided SGB using 7 mL of local anaesthetic, while the control group will receive 2 mL of saline injected into the muscle tissue on the anterolateral side of the SG. The primary outcome will be the occurrence of POD within 7 days postsurgery or before discharge. POD will be assessed two times per day using either the confusion assessment method (CAM) or the CAM for the intensive care unit. Secondary outcomes will include the severity of POD, postsurgical sleep quality, overall recovery quality and the incidence of adverse events.

ETHICS AND DISSEMINATION

The trial protocol has been approved by the Ethics Committees of the Affiliated Hospital of Jiaxing University (approval number 2023-KY-479) and Sir Run Run Shaw Hospital, Zhejiang University School of Medicine (approval number 2023-0747). Written informed consent will be obtained from all participants prior to study inclusion. Data collected will be disseminated at scientific conferences and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ChiCTR 2300077883.

Evaluation of postoperative delirium in cardiac surgery patients with the SDACS screening tool: a multicenter-multiphase study

OBJECTIVE

Postoperative delirium is a prevalent complication in cardiac surgery patients, highlighting the importance of early risk factor identification for optimal management. This study aimed to pinpoint risk factors and devise a novel screening tool, the Screening Tool for Delirium After Cardiac Surgery (SDACS), to predict postoperative delirium in cardiac surgery patients after the first day.

MATERIALS AND METHODS

This study employed a multiphase design consisting of three phases. In the first phase, through a scoping review of 38 finally selected published papers, 136 potential risk factors for identifying delirium after cardiac surgery were identified. These risk factors were then incorporated into three Delphi rounds of expert panels to develop a screening tool for postoperative delirium. Finally, 76 potential risk factors were examined on 920 cardiac surgery patients at three academic institutions between 2020 and 2023 (third phase of the study). All predictors were included into a screening instrument (SDACS), and the regression coefficient of each predictor was transformed into a risk score.

RESULTS

Delirium was diagnosed in 53% (n = 488) of 920 patients. Four independent predictors of delirium were identified: chronic opioid use (OR: 4.605, 95% CI: 2.163-9.804), hearing impairment (OR: 6.926, 95% CI: 3.630-12.215), benzodiazepine history (OR: 8.506, 95% CI: 5.651-11.805), and poor sleep quality on the first night after cardiac surgery (OR: 9.081, 95% CI: 6.225-12.248). The cross-validated area under receiver operating characteristics curve (AUC) for the screening instrument was 0.897 (95% CI: 0.876-0.916; P < 0.001).

CONCLUSION

Chronic opioid use, hearing impairment, benzodiazepine history, and poor sleep quality post-surgery are linked to postoperative delirium in cardiac surgery patients. The SDACS screening tool effectively forecasts this syndrome early, offering bedside nurses a valuable tool for prompt intervention and improved patient outcomes. The SDACS screening tool aids in early delirium risk assessment, enabling timely interventions and better patient outcomes. By predicting postoperative delirium accurately, nurses can address risk factors proactively, potentially reducing its incidence and severity, leading to improved postoperative outcomes for patients.

Preoperative Sleep Deprivation Exacerbates Anesthesia/Surgery-induced Abnormal GABAergic Neurotransmission and Neuronal Damage in the Hippocampus in Aged Mice

Older adults with anesthesia and surgery often suffer from postoperative cognitive dysfunction (POCD), which puts a heavy burden on rehabilitation. Preoperative sleep disorder, a common phenomenon in elderly anesthesia patients, is closely associated with POCD, but the underlying mechanism is still not fully understood. Hippocampal gamma-aminobutyric acid (GABA)ergic neurotransmission has been reported to play an important role in sleep disorder and cognitive impairment. The aim of this study was to elucidate the effect of preoperative acute sleep deprivation (SD) on anesthesia/surgery-induced POCD and the potential mechanism of hippocampal GABAergic neurotransmission. In the aged (18-20-month-old) male mice, we used a rotating rod to deprive sleep for 24 h and induced a POCD model using sevoflurane exposure combined with laparotomy exploration. A sequential set of behavioral tests, including open field test (OFT), Y-maze, and novel object recognition (NOR), was conducted to assess cognitive performances. In vivo magnetic resonance imaging (MRI) technique was used to observe hippocampal axonal microstructural changes. The levels of GABAergic neurotransmitter markers glutamic acid decarboxylase (GAD) 67, vesicular GABA transporter (VGAT), GABA transporter (GAT)-1, and GABA in the hippocampus were detected with enzyme-linked immunosorbent assay (ELISA). The reactivity of GABAergic neurons and neuronal damage in different subregions of the hippocampus were observed by immunofluorescence and Nissl staining, respectively. Compared the anesthesia/surgery (A/S) mice, 24-h SD combined with A/S induced shorter stay time in the central area of the open field, less the percent of novel arm preference in the Y maze, and lower recognition index in the NOR, as well as significantly enhanced hippocampal GABAergic neurotransmission, decreased hippocampal axonal integrity and density, and increased GAD67 reactivity and reduced the number of neurons in hippocampal CA1. Preoperative 24-h SD exacerbated anesthesia/surgery-induced POCD in aged mice, with the cumulative effect of abnormal GABAergic neurotransmission and neuronal damage in the hippocampus.

Association between obstructive sleep apnea and multiple adverse clinical outcomes: evidence from an umbrella review

Background and objective

In recent years, there has been a notable rise in awareness regarding obstructive sleep apnea (OSA), and a significant number of potential OSA cases have been identified. Numerous studies have established associations between OSA and various adverse clinical outcomes. This umbrella review aims to summarize and evaluate the available evidence on the relationship between OSA and multiple adverse clinical outcomes.

Methods

PubMed, Embase, and Web of Science databases were systematically searched from inception to September 2023. The AMSTAR and GRADE were used to evaluate the quality of meta-analysis literature and classify the quality of literature evidence. Furthermore, the size of the effect size of the association between OSA and adverse clinical outcomes were assessed by using either a random or fixed-effect model and 95% confidence interval (CI).

Results

A total of 27 meta-analyses were enrolled with 43 adverse clinical outcomes. The umbrella review primarily reported the associations between sleep apnea syndrome and thyroid cancer (HR = 2.32,95%CI:1.35-3.98), kidney cancer (RR = 1.81, 95% CI: 1.20-2.74), liver cancer (RR = 1.19, 95% CI: 1.10-1.29), GERD (Gastroesophageal reflux disease)(OR = 1.53, 95% CI: 1.23-1.91), Atrial fibrillation (AF) (OR = 2.54, 95% CI: 2.20-2.92), osteoporosis (OR = 2.03, 95% CI: 1.26-3.27), and diabetes (OR = 1.40, 95% CI: 1.32-1.48). Overall, the AMSTAR rating scale and GRADE quality assessment included in the meta-analysis were generally low.

Conclusion

Our study shows that OSA is significantly associated with a variety of adverse clinical outcomes, especially an increased risk of certain malignancies, and some adverse clinical outcomes are closely related to OSA severity.

Predictors of postoperative delirium in patients undergoing radical prostatectomy: a prospective study

BACKGROUND

Analyze the risk factors for postoperative delirium (POD) in elderly patients undergoing radical prostatectomy, and built a predictive nomogram model for early identification of high-risk individuals.

METHODS

A total of 156 patients was recruited and categorized based on whether the development of POD within 7 days post-surgery. After identifying independent risk factors through univariate and multivariate logistic regression analyses, predictive models were established. The discrimination and calibration were determined by C-index and calibration curve, with five-fold cross-validation executed. A nomogram model representing the optimal model was constructed based on the results.

RESULTS

POD occurred in 24 (15.38%) patients. Significant differences were observed in age, anxiety, physical status, sleep disorders, blood glucose, age-adjusted Charlson comorbidity index (ACCI), anticholinergic, blood loss, postoperative infection, and postoperative pain assessed by the numerical rating scale (NRS). Logistic regression analyses showed that sleep disorders (OR:12.931, 95% CI:1.191-140.351, P = 0.035), ACCI (OR:2.608, 95% CI:1.143-5.950, P = 0.023), postoperative infection (OR:19.298, 95% CI:2.53-147.202, P = 0.04), and NRS (OR:4.033, 95% CI:1.062-15.324, P = 0.041) were independent risk factors for POD. Model 1 (postoperative infection, ACCI, preoperative sleep disorder, NRS) showed better diagnostic performance than the others, of which the area under the curve (AUC) was 0.973. The best diagnostic performance was found in model 1 through five-fold cross-validation, with a C-index of 0.963.

CONCLUSIONS

This prospective cohort study highlighted that ACCI, preoperative sleep disorder, postoperative pain, and postoperative infection were identified as independent risk factors for POD. Furthermore, the nomogram derived from model 1 proved to be effective in predicting POD in elderly patients undergoing radical prostatectomy.

Alterations in gut microbiota and metabolites contribute to postoperative sleep disturbances

BACKGROUND

The composition of the intestinal flora and the resulting metabolites affect patients' sleep after surgery.

METHODS

We intended to elucidate the mechanisms by which disordered intestinal flora modulate the pathophysiology of postoperative sleep disturbances in hosts. In this study, we explored the impacts of anesthesia, surgery, and postoperative sleep duration on the fecal microbiota and metabolites of individuals classified postprocedurally as poor sleepers (PS) and good sleepers (GS), as diagnosed by the bispectral index. We also performed fecal microbiota transplantation in pseudo-germ-free (PGF) rats and applied Western blotting, immunohistochemistry, and gut permeability analyses to identify the potential mechanism of its effect.

RESULTS

Research finding shows the PS group had significantly higher postoperative stool levels of the metabolites tryptophan and kynurenine than the GS group. PGF rats that received gut microbiota from PSs exhibited less rapid eye movement (REM) sleep than those that received GS microbiota (GS-PGF: 11.4% ± 1.6%, PS-PGF: 4.8% ± 2.0%, p < 0.001). Measurement of 5-hydroxytryptophan (5-HTP) levels in the stool, serum, and prefrontal cortex (PFC) indicated that altered 5-HTP levels, including reduced levels in the PFC, caused sleep loss in PGF rats transplanted with PS gut flora. Through the brain-gut axis, the inactivity of tryptophan hydroxylase 1 (TPH1) and TPH2 in the colon and PFC, respectively, caused a loss of REM sleep in PGF rats and decreased the 5-HTP level in the PFC.

CONCLUSIONS

These findings indicate that postoperative gut dysbiosis and defective 5-HTP metabolism may cause postoperative sleep disturbances. Clinicians and sleep researchers may gain new insights from this study.

Current Progress on Postoperative Cognitive Dysfunction: An Update

Postoperative cognitive dysfunction (POCD) represents a significant clinical concern, particularly among elderly surgical patients. It is characterized by a decline in cognitive performance, affecting memory, attention, coordination, orientation, verbal fluency, and executive function. This decline in cognitive abilities leads to longer hospital stays and increased mortality. This review provides a comprehensive overview of the current progress in understanding the relevant pathogenic factors, possible pathogenic mechanisms, diagnosing, prevention and treatment of POCD, as well as suggesting future research directions. It discusses neuronal damage, susceptible genes, central cholinergic system, central nervous system (CNS) inflammation, stress response and glucocorticoids, and oxidative stress in the development of POCD, aiming to uncover the pathological mechanism and develop effective treatment strategies for POCD.

Intraoperative Sleep Spindle Activity and Postoperative Sleep Disturbance in Elderly Patients Undergoing Orthopedic Surgery: A Prospective Cohort Study

Purpose

This study aimed to investigate the relationship between intraoperative sleep spindle activity and postoperative sleep disturbance (PSD) in elderly orthopedic surgery patients.

Patients and Methods

In this prospective observational cohort study, we collected intraoperative electroencephalography (EEG) data from 212 elderly patients undergoing orthopedic surgery from May 2023 to December 2023. We used the Athens Insomnia Scale to assess sleep quality on postoperative day (POD) 1 and POD 3 and analyzed the correlation between intraoperative sleep spindle activity and PSD through logistic regression.

Results

The incidence of PSD was 65.6% on POD 1 and 41.9% on POD 3. On the first day, there were no significant differences in intraoperative sleep spindle characteristics between PSD and non-postoperative sleep disturbance (non-PSD) patients. However, by the third day, PSD patients showed lower sigma power compared to non-PSD patients, as well as lower spindle density in the bilateral frontopolar (Fp1/Fp2) and bilateral temporal (F7/F8) channels, with shorter average spindle duration (P < 0.05). Multivariate logistic regression analysis suggested that the average spindle density in F7/F8 channels (OR 0.543, 95% CI 0.375-0.786; P = 0.001) was an independent risk factor for PSD on POD 3. Furthermore, Mini-Mental State Examination (MMSE) could independently predict PSD on POD 1 (OR 0.806, 95% CI 0.656-0.991; P = 0.041) and POD 3 (OR 0.701, 95% CI 0.562-0.875; P = 0.002). Pain on movement and at rest were independently associated with PSD on POD 1 (OR 1.480, 95% CI 1.200-1.824; P < 0.001) and POD 3 (OR 1.848, 95% CI 1.166-2.927; P = 0.009), respectively.

Conclusion

Intraoperative mean spindle density in the F7/F8 channels was an independent risk factor for PSD on POD 3 in elderly patients undergoing orthopedic surgery. MMSE and postoperative pain also independently increased the risk of PSD.

Intraoperative Dexmedetomidine Infusion Improved Postoperative Sleep Quality and Melatonin Secretion in Patients Undergoing Elective Thoracoscopic Lung Surgery: A Prospective, Randomized Study

Background

Dexmedetomidine has been reported to improve postoperative sleep quality. However, the underlying mechanism remains unclear. This study aimed to investigate the effect of intraoperative dexmedetomidine infusion on postoperative sleep quality and changes in melatonin secretion in older patients undergoing elective thoracoscopic lung surgery.

Methods

A total of 126 older patients were randomly divided into two groups: dexmedetomidine group (Group D), which received continuous dexmedetomidine infusion at 0.3-0.5 µg/(kg·h) combined with propofol during surgery, and propofol group (Group P), which received propofol alone. The primary outcome was the postoperative sleep quality on the first postoperative night, assessed by the Richards-Campbell Sleep Questionnaire (RCSQ). Secondary outcomes included sleep quality scores on the second and third postoperative nights, melatonin concentrations postoperatively, and the incidence of delirium on the first and seventh postoperative days (discharge day).

Results

On the first postoperative night, Group D had a higher sleep quality score compared to Group P (57±11.4 vs 53±10.3; [95% CI, 1.1 to 8.7];P = 0.012), with no difference between the groups on the second and third postoperative nights. There was no statistically significant difference in the preoperative and postoperative night 3 urine 6-SMT concentrations between the two groups (P > 0.05); however, Group D had significantly higher urine 6-SMT concentrations on postoperative nights 1 and 2 compared to Group P (27 (24, 30) vs 21 (17, 24); [95% CI, -8.56 to -4.73]; P = 0.000. 28 (25, 30) vs 26 (21, 27); [95% CI, -4.37 to -1.65]; P = 0.000). There was no significant difference in the incidence of postoperative delirium between the two groups (P=0.65).

Conclusion

Continuous intraoperative infusion of dexmedetomidine can effectively improve sleep quality during the first postoperative night by promoting melatonin secretion over the first two postoperative nights.

Effects of Continuous Erector Spinae Plane Block on the Postoperative Sleep Quality for Patients Undergoing Thoracoscopic Lung Lobe Resection Surgery: A Prospective, Randomized Controlled Trial

Purpose

To investigate the effect of continuous erector spinae plane block (ESPB) on postoperative sleep in patients undergoing thoracoscopic lung lobe resection surgery.

Patients and Methods

Eighty-six patients were randomly assigned into two groups: ESPB group (Group E) or control group (Group P). Group E received ESPB before induction, followed by continuous ESPB analgesia, while Group P received postoperative intravenous controlled analgesia. The Pittsburgh Sleep Quality Index (PSQI) questionnaire was used to assess postoperative sleep disturbance (PSD) on the postoperative day 3 (POD3). The St. Mary's Hospital Sleep Questionnaire (SMH) evaluated sleep quality on the day of surgery and postoperative day 1 (POD1) and postoperative day 2 (POD2). The Identity Consequence Fatigue Scale-10 (ICFS-10) was utilized to evaluate postoperative fatigue status. Numeric Rating Scale (NRS) scores at resting and coughing were recorded at extubation, 6 h, 24 h, 48 h, 72 h after surgery. Consumption of propofol, remifentanil, and remedial analgesics (bucinazine), hospital duration, occurrence of postoperative adverse reactions were documented. Interleukin-6 (IL-6) and interleukin-10 (IL-10) serum levels were measured before surgery, 12 h, 24 h, 48 h after surgery.

Results

The incidence of PSD in group E on POD3 was significantly lower than group P (75% vs 25%). Patients in group E had higher SMH scores than group P on the day of surgery and POD2. Compared with group P, the NRS scores of resting and coughing at all time points, remifentanil and bucinazine consumption, postoperative ICFS-10 scores, the incidence of nausea and vomiting, IL-6 serum levels in group E were significantly decreased. The IL-10 serum levels in group E were significantly higher than those in group P.

Conclusion

The continuous ESPB can improve postoperative sleep quality, alleviate pain, fatigue and inflammation, and reduce the incidence of postoperative nausea and vomiting.

Alterations in hippocampal somatostatin interneurons, GABAergic metabolism, and ASL perfusion in an aged male mouse model of POCD aggravated by sleep fragmentation

Sleep fragmentation (SF) is increasingly recognized as a contributing factor to postoperative cognitive dysfunction (POCD). Given the critical roles of somatostatin (SST) interneurons, associated gamma-aminobutyric acid (GABA)ergic neurotransmitters, and hippocampal perfusion in sleep-related cognition, this study examined changes in these mechanisms in preoperative SF affecting POCD induced by anesthesia/surgery in aged male mice. The Morris water maze (MWM), novel object recognition (NOR), and Y maze tests were utilized to evaluate POCD. Arterial spin labeling (ASL) was employed to measure hippocampal regional cerebral blood flow (rCBF). In vitro assays quantified the levels of GABAergic metabolites-such as SST, neuropeptide Y (NPY), glutamic acid decarboxylase 1 (GAD1), vesicular GABA transporter (VGAT), and GABA and the distribution of SST interneurons in the hippocampus through enzyme-linked immunosorbent assay and immunofluorescence. Preoperative 24-h SF exacerbated anesthesia/surgery-induced spatial memory impairments observed in the MWM, NOR, and Y maze tests. Preoperative 24-h SF significantly increased the number of SST interneurons in hippocampal CA1, elevated hippocampal levels of SST, NPY, GAD1, and GABA, and reduced the rCBF. Preoperative SF aggravated POCD in aged male mice, with an increased number of SST interneurons in hippocampal CA1, elevated hippocampal GABAergic metabolites, and a further reduction in rCBF.

Association between perioperative self-reported sleep disturbances and delirium risk in elderly patients following total joint arthroplasty: a cohort study

Perioperative sleep disturbance may increase delirium risk. However, the role of perioperative sleep disturbance in delirium following total joint arthroplasty remains unclear. This prospective cohort study aimed to observe the delirium risk in patients with sleep disturbances. After excluding pre-existing sleep disturbances, older patients scheduled for total joint arthroplasty from July 17, 2022, to January 12, 2023, were recruited. Preoperative sleep disturbance or postoperative sleep disturbance was defined as a Chinese version of the Richards-Campbell Sleep Questionnaire (RCSQ) score of <50 during hospitalisation. A cut-off score of 25 was used to classify the severity of sleep disturbance. The primary outcome was the incidence of postoperative delirium. In all, 11.6% of cohort patients (34/294) developed delirium. After multivariate analysis, a preoperative Day 1 RCSQ score of ≤25 (odds ratio [OR] 3.62, 95% confidence interval [CI] 1.19-10.92; p = 0.02), occurrence of sleep disturbances (OR 2.76, 95% CI 1.19-6.38; p = 0.02) and RCSQ score of ≤25(OR 2.91, 95% CI 1.33-6.37; p = 0.007) postoperatively were strong independent predictors of delirium. After sensitivity analysis for daily delirium, a postoperative Day 1 RCSQ score of ≤25 (OR 9.27, 95% CI 2.72-36.15; p < 0.001) was associated with a greater risk of delirium on postoperative Day 1, with a reasonable discriminative area under the curve of 0.730. We concluded that postoperative but not preoperative sleep disturbances may be an independent factor for delirium risk. Sleep disturbance on the first night after surgery was a good predictor of subsequent delirium, no matter the nature of self-reported sleep disturbance.

Effect of desflurane maintenance on postoperative sleep quality in patients undergoing elective breast surgery: A non-inferiority randomized controlled trial

BACKGROUND

Postoperative sleep disturbance (PSD) is prevalent in perioperative patients，and has significant impact on postoperative recovery and prognosis. The aim of this study was to investigate the effect of desflurane maintenance on postoperative sleep quality, in order to optimize patients' perioperative sleep management.

METHOD

A total of 118 patients undergoing elective breast surgery were randomized to receive either desflurane-based volatile anesthesia (desflurane group) or propofol-based total intravenous anesthesia (propofol group) for anesthesia maintenance. The primary outcome was the quality of sleep, which was assessed by the Pittsburgh Sleep Quality Index (PSQI) on 3 days after operation (POD3). Secondary outcomes were PSQI on postoperative day 7 (POD7) and 30 (POD30), and postoperative anxiety, depression, and pain score, as well as objective sleep parameters including total sleep time (TST), WASO (Wakefulness after sleep onset), REM (Rapid eye movement) and NREM (Non-rapid Eye Movement) measured by Fitbit Charge 2TM during the initial 3 postoperative days.

RESULTS

The global PSQI scores on POD3 in the desflurane group was non-inferior to that in the propofol group [mean (SD) 8.47 (3.46) vs. 7.65 (3.16); mean difference (95 % CI) 0.82 (-0.43, 2.07); p < 0.001 for non-inferiority]. There were no significant differences in PSQI scores on POD3 and POD7. In addition, the score of anxiety, depression, and pain on the 3rd, 7th, and 30th day after surgery have no significant differences between the propofol and the desflurane group, respectively. The postoperative NREM was higher in the desflurane group than that in the propofol group.

CONCLUSION

The effects of desflurane-based volatile anesthesia maintenance on postoperative sleep quality is not inferior to that of propofol-based total intravenous anesthesia, and these two drugs may have different effects on the sleep structure.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04805775.

Preoperative recovery sleep ameliorates postoperative cognitive dysfunction aggravated by sleep fragmentation in aged mice by enhancing EEG delta-wave activity and LFP theta oscillation in hippocampal CA1

Sleep fragmentation (SF) is a common sleep problem experienced during the perioperative period by older adults, and is associated with postoperative cognitive dysfunction (POCD). Increasing evidence indicates that delta-wave activity during non-rapid eye movement (NREM) sleep is involved in sleep-dependent memory consolidation and that hippocampal theta oscillations are related to spatial exploratory memory. Recovery sleep (RS), a self-regulated state of sleep homeostasis, enhances delta-wave power and memory performance in sleep-deprived older mice. However, it remains unclear whether RS therapy has a positive effect on cognitive changes following SF in older mouse models. Therefore, this study aimed to explore whether preoperative RS can alleviate cognitive deficits in aged mice with SF. A model of preoperative 24-h SF combined with exploratory laparotomy-induced POCD was established in 18-month-old mice. Aged mice were treated with preoperative 6-h RS following SF and postoperative 6-h RS following surgery, respectively. The changes in hippocampus-dependent cognitive function were investigated using behavioral tests, electroencephalography (EEG), local field potential (LFP), magnetic resonance imaging, and neuromorphology. Mice that underwent 24-h SF combined with surgery exhibited severe spatial memory impairment; impaired cognitive performance could be alleviated by preoperative RS treatment. In addition, preoperative RS increased NREM sleep; enhanced EEG delta-wave activity and LFP theta oscillation in the hippocampal CA1; and improved hippocampal perfusion, microstructural integrity, and neuronal damage. Taken together, these results provide evidence that preoperative RS may ameliorate the severity of POCD aggravated by SF by enhancing delta slow-wave activity and hippocampal theta oscillation, and by ameliorating the reduction in regional cerebral blood flow and white matter microstructure integrity in the hippocampus.

Postoperative cognitive dysfunction: spotlight on light, circadian rhythms, and sleep

Postoperative cognitive dysfunction (POCD) is a neurological disorder characterized by the emergence of cognitive impairment after surgery. A growing body of literature suggests that the onset of POCD is closely tied to circadian rhythm disruption (CRD). Circadian rhythms are patterns of behavioral and physiological change that repeat themselves at approximately, but not exactly, every 24 h. They are entrained to the 24 h day by the daily light-dark cycle. Postoperative CRD affects cognitive function likely by disrupting sleep architecture, which in turn provokes a host of pathological processes including neuroinflammation, blood-brain barrier disturbances, and glymphatic pathway dysfunction. Therefore, to address the pathogenesis of POCD it is first necessary to correct the dysregulated circadian rhythms that often occur in surgical patients. This narrative review summarizes the evidence for CRD as a key contributor to POCD and concludes with a brief discussion of how circadian-effective hospital lighting can be employed to re-entrain stable and robust circadian rhythms in surgical patients.

Association Between Preoperative Sleep Disturbance and Postoperative Delirium in Elderly: A Retrospective Cohort Study

Purpose

Postoperative sleep disturbance, characterized by diminished postoperative sleep quality, is a risk factor for postoperative delirium (POD); however, the association between pre-existing sleep disturbance and POD remains unclear. This study aimed to evaluate the association between preoperative sleep disturbance and POD in elderly patients after non-cardiac surgery.

Patients and methods

This retrospective cohort study was conducted at a single center and enrolled 489 elderly patients who underwent surgery between May 1, 2020, and March 31, 2021. Patients were divided into the sleep disorder (SD) and non-sleep disorder (NSD) groups according to the occurrence of one or more symptoms of insomnia within one month or sleep- Numerical Rating Scale (NRS)≥6 before surgery. The primary outcome was the incidence of POD. Propensity score matching analysis was performed between the two groups. Multiple logistic regression analysis was performed to identify the risk factors for POD.

Results

In both the unmatched cohort (16.0% vs 6.7%, P=0.003) and the matched cohort (17.0% vs 6.2%, P=0.023), the incidence of POD was higher in the SD group than in the NSD group. In addition, the postoperative sleep quality and the VAS score at postoperative 24 h were significantly lower in the SD group than in the NSD group. Multivariate logistic regression analysis indicated that age (Odds Ratio, 1.13 [95% CI: 1.04-1.23], P=0.003) and preoperative sleep disturbance (Odds Ratio, 3.03 [95% CI: 1.09-9.52], P=0.034) were independent risk factors for the development of POD.

Conclusion

The incidence of POD was higher in patients with pre-existing sleep disturbance than those without it. Whether improving sleep quality for preoperative sleep disturbance may help prevent POD remains to be determined.

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.

Melanin-Concentrating Hormone Is Associated With Delayed Neurocognitive Recovery in Older Adult Patients With Preoperative Sleep Disorders Undergoing Spinal Anesthesia

BACKGROUND

Aging and preoperative sleep disorders are the main risk factors affecting postoperative cognitive outcomes. However, the pathogenesis of delayed neurocognitive recovery after surgery remains ambiguous, and there is still a lack of potential biomarkers for delayed neurocognitive recovery in older adult patients with preoperative sleep disorders. Our study aimed to explore the relationship between melanin-concentrating hormone (MCH) and delayed neurocognitive recovery early after surgery in older adult patients with preoperative sleep disorders.

METHODS

In this monocentric prospective observational study, 156 older adult patients (aged 65 years or older) with preoperative sleep disorders undergoing elective total hip arthroplasty (THA) or total knee arthroplasty (TKA) were included at an academic medical center in Inner Mongolia, China, from October 2021 to November 2022, and all patients underwent spinal anesthesia. The Pittsburgh Sleep Quality Index (PSQI) was applied to assess the preoperative sleep quality of all patients, and preoperative sleep disorders were defined as a score of PSQI >5. We measured the levels of cerebrospinal fluid (CSF) MCH and plasma MCH of all patients. The primary outcome was delayed neurocognitive recovery early after surgery. All patients received cognitive function assessment through the Montreal Cognitive Assessment (MoCA) 1 day before and 7 days after surgery (postoperative day 7 [POD7]). Delayed neurocognitive recovery was defined as a score of POD7 MoCA <26. The potential confounders included variables with P < .2 in the univariate logistic analysis, as well as the important risk factors of delayed neurocognitive recovery reported in the literature. Multivariable logistic regression model based on the Enter method assessed the association of MCH and delayed neurocognitive recovery in older adult patients with preoperative sleep disorders.

RESULTS

Fifty-nine (37.8%) older adult patients with preoperative sleep disorders experienced delayed neurocognitive recovery at POD7. Increase in CSF MCH levels (odds ratio [OR] for an increase of 1 pg/mL = 1.16, 95% confidence interval [CI], 1.09-1.23, P < .001) and decrease in plasma MCH levels (OR for an increase of 1 pg/mL = 0.92, 95% CI, 0.86-0.98, P = .003) were associated with delayed neurocognitive recovery, after adjusting for age, sex, education, baseline MoCA scores, American Society of Anesthesiologists (ASA) grade, and coronary heart disease (CHD).

CONCLUSIONS

In older adult patients with preoperative sleep disorders, MCH is associated with the occurrence of delayed neurocognitive recovery after surgery. Preoperative testing of CSF MCH or plasma MCH may increase the likelihood of identifying the high-risk population for delayed neurocognitive recovery in older adult patients with preoperative sleep disorders.

Effects of Acupuncture-Point Stimulation on Perioperative Sleep Disorders: A Systematic Review with Meta-Analysis and Trial Sequential Analysis

Background

Perioperative sleep disorders exert a severe adverse impact on postoperative recovery. Recently, some observational studies reported that acupuncture-point stimulation (APS) provided benefits for promoting perioperative sleep quality. However, the effects of APS on perioperative sleep disorders following general anesthesia have not been thoroughly assessed by any systematic study and meta-analysis. Therefore, we conducted this systematic review and meta-analysis to reveal the effects of APS on perioperative sleep disorders.

Methods

Eight databases (Chinese: CNKI, VIP, CBM, and Wanfang; English: PubMed, Embase, Web of Science, and Cochrane Library) were thoroughly searched to find randomized controlled trials (RCTs) that indicated a link between APS and the occurrence of perioperative sleep disorders. We applied RevMan 5.4 (Cochrane Collaboration) and Stata 16.0 (Stata Corp) to conduct our meta-analysis. In addition, the trial sequential analysis (TSA) tool was utilized to estimate the validity and reliability of the data.

Results

In this study, nine RCTs with 719 patients were conducted. Compared to the control group, APS significantly improved perioperative subjective sleep quality (SMD: -1.36; 95% CI: -1.71 to -1.01; P < 0.00001). Besides, it increased perioperative TST (preoperative period MD = 24.29, 95% CI: 6.4 to 42.18, P = 0.0008; postoperative period MD = 45.86, 95% CI: 30.00 to 61.71, P < 0.00001) and SE (preoperative MD = 3.62, 95% CI: 2.84 to 4.39, P < 0.00001; postoperative MD = 6.43, 95% CI: 0.95 to 11.73, P < 0.00001). The consequence of trial sequential analysis further confirmed the reliability of our meta-analysis results.

Conclusion

According to the currently available evidence, APS could effectively improve perioperative sleep quality and play an essential role in decreasing the incidence of perioperative sleep disorders.

Different Doses of Dexmedetomidine Reduce Postoperative Sleep Disturbance Incidence in Patients under General Anesthesia by Elevating Serum Neurotransmitter Levels

Postoperative sleep disturbance is a common issue that affects recovery in patients undergoing general anesthesia. Dexmedetomidine (Dex) has a potential role in improving postoperative sleep quality. We evaluated the effects of different doses of Dex on postoperative sleep disturbance and serum neurotransmitters in patients undergoing radical gastrectomy under general anesthesia. Patients were assigned to the control, NS, and Dex (Dex-L/M/H) groups based on different treatment doses [0.2, 0.4, and 0.6 μg/(kg · h)]. The Athens Insomnia Scale (AIS) and ELISA kits were used to assess sleep disturbance and serum neurotransmitter (GABA, 5-HT, NE) levels before surgery and on postoperative days one, four, and seven. The effects of different doses on postoperative sleep disturbance incidence and serum neurotransmitter levels were analyzed by the Fisher exact test and one-way and repeated-measures ANOVA. Patients had no differences in gender, age, body mass index, operation time, and bleeding volume. Different Dex doses reduced the postoperative AIS score of patients under general anesthesia, improved their sleep, and increased serum levels of 5-HT, NE, and GABA. Furthermore, the effects were dose-dependent within the range of safe clinical use. Specifically, Dex at doses of 0.2, 0.4, and 0.6 μg/(kg · h) reduced postoperative AIS score, elevated serum neurotransmitter levels, and reduced postoperative sleep disturbance incidence. Collectively, Dex has a potential preventive effect on postoperative sleep disturbance in patients undergoing general anesthesia for radical gastrectomy. The optimal dose of Dex is between 0.2 and 0.6 μg/(kg · h), which significantly reduces the incidence of postoperative sleep disturbance and increases serum neurotransmitter levels.

Interplay between stress, sleep, and BDNF in a high-risk sample of young adults

Children in institutional care have a high risk to experience childhood adversities (CAs), with consequences for physical and mental well-being. The long-term effects of CAs on the brain, including consequences for neuronal plasticity and sleep, are poorly understood. This study examined the interplay between stress (including CAs), sleep, and brain-derived neurotrophic factor (BDNF), a prominent marker for neuronal plasticity. Participants (N = 131, mean age = 26.3±3.4 years, 40 females) with residential youth-care history completed questionnaires measuring CAs (Childhood Trauma Questionnaire, CTQ), psychological well-being (World Health Organization-Five Well-Being Index, WHO-5), and sleep disturbances (Pittsburgh Sleep Quality Inventory, PSQI). Hair cortisol and serum BDNF concentration were measured using enzyme-linked immunosorbent assays. The analyses were conducted by using bootstrap regression models. There was no association of stress parameters or sleep with BDNF concentration. However, we found a significant association of CAs and well-being with sleep disturbances. Last, we found an association between CAs and BDNF in sleep-healthy but not sleep-disturbed participants. Our findings indicated a role of sleep disturbance in the association between stress and BDNF. Still, further studies are warranted using vulnerable groups at-risk to understand long-term effects on mental health and sleep.

Intranasal dexmedetomidine improves postoperative sleep quality in older patients with chronic insomnia: a randomized double-blind controlled trial

Objective: This study was determined to investigate the impact of intranasal dexmedetomidine (DEX) on postoperative sleep quality in older patients (age over 65) with chronic insomnia during their hospitalization after surgery. Design: A randomized double-blind controlled trial was conducted to compare the effects of intranasal dexmedetomidine spray with a placebo group. Setting and Participants: The study was carried out at Xiangya Hospital, Central South University. 110 participants with chronic insomnia were analyzed. Methods: This trial enrolled older patients who underwent total hip/knee arthroplasty and randomized them to receive intranasal dexmedetomidine (2.0 μg/kg) or saline daily at around 9 p.m. after surgery until discharge. The primary outcomes were subjective sleep quality assessed with the Leeds Sleep Evaluation Questionnaire (LSEQ). The secondary outcomes included the objective sleep quality measured with the Acti-graph, the Pittsburgh Sleep Quality Index (PSQI), the Insomnia Severity Index (ISI). The other outcomes included the incidence of delirium, levels of inflammatory factors, visual analog scale (VAS) pain scores, postoperative opioid consumption, and treatment-related adverse events. Results: 174 patients were screened for eligibility, and 110 were recruited and analyzed. The DEX group had significantly higher scores on both the LSEQ-Getting to sleep and LSEQ-Quality of Sleep at each time point compared to the placebo (p < 0.0001), The least squares (LS) mean difference in LSEQ-GTS score at T0 between placebo group and DEX group was 2 (95% CI, -1-6), p = 0.4071 and at T5 was -14 (95% CI, -17 to -10), p < 0.0001; The LS mean difference in the LSEQ-QOS score at T0 was -1 (95% CI, -4 to 1), p = 0.4821 and at T5 was -16 (95% CI, -21 to -10), p < 0.0001. The DEX group exhibited significant improvement in Total Sleep Time (TST), Sleep Onset Latency (SOL), and Sleep Efficiency (SE), at each time point after treatment compared to the placebo group (p < 0.0001). The PSQI and ISI scores in the DEX group were reduced after treatment (p < 0.001). No significant adverse events were reported with the use of dexmedetomidine. Conclusion and Implications: This study demonstrates that intranasal administration of dexmedetomidine improves postoperative sleep quality in older patients with chronic insomnia who undergo surgery, without increasing the incidence of adverse effects. Clinical Trial Registration: http://www.chictr.org.cn/, identifier ChiCTR2200057133.

Delirium and sleep disturbances-A narrative review

BACKGROUND

Delirium is considered a severe complication. It increases morbidity and mortality and represents a major financial burden for healthcare systems. Thus, prevention becomes a focal point of research. Sleep disturbances have been linked to the occurrence of delirium. Consequently, several interventions that target a possible connection have been studied in recent years.

OBJECTIVE

This narrative literature review explores the published data for an association between delirium and different types of sleep disturbances, the pathophysiological interactions and prevention methods.

MATERIAL AND METHODS

A literature search was carried out utilizing PubMed, the Cochrane Library, Livivo and Google Scholar.

RESULTS

Although an association between several types of sleep disturbances and delirium has been shown, no causality has been proven so far. Nevertheless, several pharmacological and nonpharmacological interventions for delirium prevention have been attempted; however, the level of evidence is insufficient at this point.

CONCLUSION

Further research is required to prove causality between sleep disturbances and delirium. Nonpharmacological interventions should be used in construction and maintenance of intensive care units and hospitals. Pharmacological interventions could be effective for prevention but further research is needed. Screening patients at risk of delirium for sleep disturbances and antihistaminergic/anticholinergic medication seems beneficial.

Postsurgery Subjective Cognitive and Short-Term Memory Impairment Among Middle-Aged Chinese Patients

Importance

Perioperative neurocognitive disorder, particularly postoperative cognitive impairment, is common and associated with multiple medical and social adversities, although data from China are lacking.

Objective

To examine the incidence, trajectory, and risk factors for subjective cognitive and short-term memory impairment after surgery in the Chinese population.

Design, Setting, and Participants

This cohort study used data from the China Surgery and Anesthesia Cohort to assess surgical patients aged 40 to 65 years from 2 medical centers between July 15, 2020, and March 31, 2023, with active follow-up within 1 year after the surgery. Of 11 158 patients who were successfully recruited (response rate, 94.4%), 10 149 participants were eligible and available for analysis. From this population, separate cohorts were constructed for analyzing subjective cognitive impairment (8105 noncardiac and 678 cardiac surgery patients) and short-term memory impairment (5246 noncardiac and 454 cardiac surgery patients).

Exposures

Twenty-four potential risk factors regarding comorbidities, preoperative psychological conditions, anesthesia- or surgery-related factors, and postsurgical events were included.

Main Outcomes and Measures

Outcomes included subjective cognitive function measured by the 8-Item Informant Interview to Differentiate Aging and Dementia (AD8; scores range from 0 to 8, with higher scores indicating more severe cognitive impairment) and short-term memory measured by the 3-Word Recall Test (TRT; scores range from 0 to 3, with lower scores indicating more severe short-term memory impairment) at 1, 3, 6, and 12 months after noncardiac and cardiac surgery. Generalized linear mixed models were used to identify risk factors associated with the presence of AD8 (score ≥2) or TRT (score <3) abnormality as well as the aggressively deteriorative trajectories of those cognitive measurements.

Results

For noncardiac surgery patients, the AD8 analysis included 8105 patients (mean [SD] age, 52.3 [7.1] years; 3378 [41.7%] male), and the TRT analysis included 5246 patients (mean [SD] age, 51.4 [7.0] years; 1969 [37.5%] male). The AD8 abnormality incidence rates after noncardiac surgery increased from 2.2% (175 of 8105) at 7 days to 17.1% (1059 of 6191) at 6 months after surgery, before appearing to decrease. In contrast, the TRT abnormality incidence rates followed a U-shaped pattern, with the most pronounced incidence rates seen at 7 days (38.9% [2040 of 5246]) and 12 months (49.0% [1394 of 2845]). Similar patterns were seen among cardiac surgery patients for the AD8 analysis (678 patients; mean [SD] age, 53.2 [6.3] years; 393 [58.0%] male) and TRT analysis (454 patients; mean [SD] age, 52.4 [6.4] years; 248 [54.6%] male). Among noncardiac surgery patients, the top risk factors for aggressively deteriorative AD8 trajectory and for AD8 abnormality, respectively, after surgery were preoperative sleep disturbances (Pittsburgh Sleep Quality Index ≥16 vs 0-5: odds ratios [ORs], 4.04 [95% CI, 2.20-7.40] and 4.54 [95% CI, 2.40-8.59]), intensive care unit stay of 2 days or longer (ORs, 2.43 [95% CI, 1.26-4.67] and 3.07 [95% CI, 1.67-5.65]), and preoperative depressive symptoms (ORs, 1.76 [95% CI, 1.38-2.24] and 2.23 [95% CI, 1.79-2.77]). Analyses for TRT abnormality and trajectory, as well as the analyses conducted among cardiac surgery patients, found fewer associated factors.

Conclusions and Relevance

This cohort study of middle-aged Chinese surgery patients found subjective cognitive and short-term memory impairment within 12 months after both cardiac and noncardiac surgery, with multiple identified risk factors, underscoring the potential of preoperative psychological interventions and optimized perioperative management for postoperative cognitive impairment prevention.

Preoperative slow-wave sleep is associated with postoperative delirium after heart valve surgery: A prospective pilot study

Postoperative delirium (POD) is a very common neurological complication after valve surgery. Some studies have shown that preoperative sleep disorder is associated with POD, but the correlation between preoperative slow wave sleep (SWS) and POD remains unclear. Therefore, this study aims to identify the correlation between preoperative slow wave sleep and postoperative delirium in patients with heart valve disease. This was a prospective, observational study of elective valve surgery patients admitted to the Heart Medical Center between November 2021 and July 2022. Polysomnography (PSG) was used to monitor sleep architecture from 9:30 p.m. for 1 night before surgery to 6:30 a.m. on the day of surgery. Patients were assessed for postoperative delirium from postoperative day 1 to extubation or day 5 by using the Richmond Agitation/Sedation Scale (RASS) and the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU). A total of 60 elective valve surgery patients were enrolled in this study. Prolonged N1 (11.44%) and N2 (58.62%) sleep, decreased N3 sleep (8.75%) and REM sleep (18.24%) within normal limits were the overall sleep architecture. Compared with patients without POD, patients with POD had less slow wave sleep 1 night before surgery (5.77% vs 10.88%, p < 0.001). After adjusting for confounding factors, slow wave sleep (OR: 0.647, 95% CI 0.493-0.851, p = 0.002) was found to be a protective factor for postoperative delirium. The preoperative SWS is a predictive factor of the POD in patients undergoing valve surgery. But further studies with larger sample sizes are still needed to elucidate the relationship between preoperative slow wave sleep and postoperative delirium.

Effects of Propofol on Perioperative Sleep Quality in Patients Undergoing Gastrointestinal Endoscopy: A Prospective Cohort Study

PURPOSE

Some patients experience sleep disturbances after endoscopy performed under sedation. This study aimed to evaluate the effects of propofol on sleep quality after gastrointestinal endoscopy (GE).

DESIGN

This study was a prospective cohort study.

METHODS

This study enrolled 880 patients who underwent GE. Patients who chose to undergo GE under sedation received intravenous propofol, whereas the control group did not. The Pittsburgh Sleep Quality Index (PSQI) was measured before GE (PSQI-1) and 3 weeks (PSQI-2) after GE. The Groningen Sleep Score Scale (GSQS) was used before GE (GSQS-1) and 1 (GSQS-2) and 7 days (GSQS-3) after GE.

FINDINGS

There was a significant increase in GSQS scores from baseline to days 1 and 7 after GE (GSQS-2 vs GSQS-1, P < .001, GSQS-3 vs GSQS-1, P = .008). However, no significant changes were observed in the control group (GSQS-2 vs GSQS-1, P = .38, GSQS-3 vs GSQS-1, P = .66). On day 21, there were no significant changes in the baseline PSQI scores over time in either group (sedation group, P = .96; control group, P = .95).

CONCLUSIONS

GE with propofol sedation negatively affected sleep quality for 7 days after GE but not 3 weeks after GE.

Association and prediction of subjective sleep quality and postoperative delirium during major non-cardiac surgery: a prospective observational study

BACKGROUND

Postoperative delirium (POD) is an acute form of brain dysfunction that can result in serious adverse consequences. There has been a link between cognitive dysfunction and poor sleep. The present study aimed to determine the association and prediction of subjective sleep quality and postoperative delirium during major non-cardiac surgery.

METHODS

One hundred and thirty-four patients, aged 60 years or older, were scheduled for elective laparotomy or orthopaedic procedures. The Pittsburgh Sleep Quality Index (PSQI) and sleep log were used to assess perioperative subjective sleep quality in participants. Nursing Delirium Screening Checklist (NU-DESC) was used for screening, and the Confusion Assessment Method (CAM) was used to diagnose POD during the first seven days following surgery. The association between subjective sleep quality and POD was assessed using a multivariate logistic regression model. Thereafter, the prediction performance of subjective sleep quality was evaluated using a receiver operating characteristic (ROC) curve.

RESULTS

All assessments were completed on 119 patients who had an average PSQI score of 7.0 ± 2.4 before surgery. 23 patients (19.3%) suffered from POD. The multivariate logistic regression analysis showed that the occurrence of POD was closely related to age, BMI, PSQI and operation time. After adjusting for related factors, there was a statistically significant association between PSQI and POD occurrence (OR = 1.422, 95%CI 1.079-1.873, per 1-point increase in PSQI). The ROC curve analysis showed that the optimal PSQI cutoff value was 8.0 for predicting POD, and the area under the ROC (AUROC) value of PSQI was 0.741 (95%CI 0.635 to 0.817). The AUROC of the model developed by the multivariate logistic regression analysis was 0.870 (95%CI 0.797 to 0.925).

CONCLUSIONS

The study found that preoperative subjective sleep quality was strongly associated with POD during major non-cardiac surgery. Additionally, PSQI combined with age, BMI, and operation time improved POD prediction.

Associations between perioperative sleep patterns and clinical outcomes in patients with intracranial tumors: a correlation study

Objective

Although the quality of perioperative sleep is gaining increasing attention in clinical recovery, its impact role remains unknown and may deserve further exploration. This study aimed to investigate the associations between perioperative sleep patterns and clinical outcomes among patients with intracranial tumors.

Methods

A correlation study was conducted in patients with intracranial tumors. Perioperative sleep patterns were assessed using a dedicated sleep monitor for 6 consecutive days. Clinical outcomes were gained through medical records and follow-up. Spearman's correlation coefficient and multiple linear regression analysis were applied to evaluate the associations between perioperative sleep patterns and clinical outcomes.

Results

Of 110 patients, 48 (43.6%) were men, with a median age of 57 years. A total of 618 days of data on perioperative sleep patterns were collected and analyzed. Multiple linear regression models revealed that the preoperative blood glucose was positively related to the preoperative frequency of awakenings (β = 0.125; 95% CI = 0.029-0.221; P = 0.011). The level of post-operative nausea and vomiting was negatively related to perioperative deep sleep time (β = -0.015; 95% CI = -0.027--0.003; P = 0.015). The level of anxiety and depression was negatively related to perioperative deep sleep time, respectively (β = -0.048; 95% CI = -0.089-0.008; P = 0.020, β = -0.041; 95% CI = -0.076-0.006; P = 0.021). The comprehensive complication index was positively related to the perioperative frequency of awakenings (β = 3.075; 95% CI = 1.080-5.070; P = 0.003). The post-operative length of stay was negatively related to perioperative deep sleep time (β = -0.067; 95% CI = -0.113-0.021; P = 0.005). The Pittsburgh Sleep Quality Index was positively related to perioperative sleep onset latency (β = 0.097; 95% CI = 0.044-0.150; P < 0.001) and negatively related to perioperative deep sleep time (β = -0.079; 95% CI = -0.122-0.035; P < 0.001).

Conclusion

Perioperative sleep patterns are associated with different clinical outcomes. Poor perioperative sleep quality, especially reduced deep sleep time, has a negative impact on clinical outcomes. Clinicians should, therefore, pay more attention to sleep quality and improve it during the perioperative period.

Clinical trial registration

http://www.chictr.org.cn, identifier: ChiCTR2200059425.

Neurometabolic and structural alterations of medial septum and hippocampal CA1 in a model of post-operative sleep fragmentation in aged mice: a study combining 1H-MRS and DTI

Post-operative sleep disturbance is a common feature of elderly surgical patients, and sleep fragmentation (SF) is closely related to post-operative cognitive dysfunction (POCD). SF is characterized by sleep interruption, increased number of awakenings and sleep structure destruction, similar to obstructive sleep apnea (OSA). Research shows that sleep interruption can change neurotransmitter metabolism and structural connectivity in sleep and cognitive brain regions, of which the medial septum and hippocampal CA1 are key brain regions connecting sleep and cognitive processes. Proton magnetic resonance spectroscopy (1H-MRS) is a non-invasive method for the evaluation of neurometabolic abnormalities. Diffusion tensor imaging (DTI) realizes the observation of structural integrity and connectivity of brain regions of interest in vivo. However, it is unclear whether post-operative SF induces harmful changes in neurotransmitters and structures of the key brain regions and their contribution to POCD. In this study, we evaluated the effects of post-operative SF on neurotransmitter metabolism and structural integrity of medial septum and hippocampal CA1 in aged C57BL/6J male mice. The animals received a 24-h SF procedure after isoflurane anesthesia and right carotid artery exposure surgery. 1H-MRS results showed after post-operative SF, the glutamate (Glu)/creatine (Cr) and glutamate + glutamine (Glx)/Cr ratios increased in the medial septum and hippocampal CA1, while the NAA/Cr ratio decreased in the hippocampal CA1. DTI results showed post-operative SF decreased the fractional anisotropy (FA) of white matter fibers in the hippocampal CA1, while the medial septum was not affected. Moreover, post-operative SF aggravated subsequent Y-maze and novel object recognition performances accompanied by abnormal enhancement of glutamatergic metabolism signal. This study suggests that 24-h SF induces hyperglutamate metabolism level and microstructural connectivity damage in sleep and cognitive brain regions in aged mice, which may be involved in the pathophysiological process of POCD.

The prevalence and risk factors of sleep disturbances in surgical patients: A systematic review and meta-analysis

Determining the prevalence and risk factors related to sleep disturbance in surgical patients would be beneficial for risk stratification and perioperative care planning. The objectives of this systematic review and meta-analysis are to determine the prevalence and risk factors of sleep disturbances and their associated postoperative complications in surgical patients. The inclusion criteria were: (1) patients ≥18 years old undergoing a surgical procedure, (2) in-patient population, and (3) report of sleep disturbances using a validated sleep assessment tool. The systematic search resulted in 21,951 articles. Twelve patient cohorts involving 1497 patients were included. The pooled prevalence of sleep disturbances at preoperative assessment was 60% (95% Confidence Interval (CI): 50%, 69%) and the risk factors for postoperative sleep disturbances were a high preoperative Pittsburgh sleep quality index (PSQI) score indicating preexisting disturbed sleep and anxiety. Notably, patients with postoperative delirium had a higher prevalence of pre- and postoperative sleep disturbances and high preoperative wake after sleep onset percentage (WASO%). The high prevalence of preoperative sleep disturbances in surgical patients has a negative impact on postoperative outcomes and well-being. Further work in this area is warranted.

Pharmacotherapy for improving postoperative sleep quality: a protocol for a systematic review and network meta-analysis

INTRODUCTION

Improving the quality of sleep may promote enhanced recovery in surgical patients. In addition to controversial or conflicting study conclusions, the current clinical studies on pharmacotherapy for improving postoperative sleep quality are mostly limited to evaluating the effect of a specific drug or supplement compared with placebo, and they lack comparisons between drugs or supplements. Therefore, we plan to conduct a systematic review and network meta-analysis to compare the efficacy of different drugs or supplements for improving postoperative sleep quality.

METHODS AND ANALYSIS

We will search the MEDLINE, Embase, Cochrane Central Register of Controlled Trials, CNKI and Wanfang databases from the dates of their inception to December 2022. We will only include randomised controlled trials, irrespective of language and publication status. The primary outcome is postoperative sleep quality assessed by any validated tools or polysomnography. We will assess the quality of all included trials according to version 2 of the Cochrane risk-of-bias tool for randomised trials. We will use the GeMTC package of R software to perform direct and indirect comparisons via a Bayesian framework using a random-effects model. We will use the Confidence in Network Meta-Analysis approach to evaluate the quality of evidence.

ETHICS AND DISSEMINATION

Ethical approval is not required for this protocol because we will only be pooling published data. We plan to submit our review to academic conferences and peer-reviewed academic journals.

PROSPERO REGISTRATION NUMBER

CRD42022356508.

Effect of Intraoperative Esketamine Infusion on Postoperative Sleep Disturbance After Gynecological Laparoscopy: A Randomized Clinical Trial

IMPORTANCE

Postoperative sleep disturbance (PSD) is common in patients after surgery.

OBJECTIVE

To examine the effect of intraoperative esketamine infusion on the incidence of PSD in patients who underwent gynecological laparoscopic surgery.

DESIGN, SETTING, AND PARTICIPANTS

This single-center, double-blind, placebo-controlled randomized clinical trial was conducted from August 2021 to April 2022 in the First Affiliated Hospital of Zhengzhou University in China. Participants included patients aged 18 to 65 years with an American Society of Anesthesiologist Physical Status classification of I to III (with I indicating a healthy patient, II a patient with mild systemic disease, and III a patient with severe systemic disease) who underwent gynecological laparoscopic surgery. Patients were randomly assigned to either the esketamine group or control group. Data were analyzed using the per protocol principle.

INTERVENTIONS

Patients in the esketamine group received a continuous infusion of esketamine, 0.3 mg/kg/h, intraoperatively. Patients in the control group received an equivalent volume of saline.

MAIN OUTCOMES AND MEASURES

The primary outcome was the incidence of PSD on postoperative days (PODs) 1 and 3. Postoperative sleep disturbance was defined as a numeric rating scale score of 6 or higher or an Athens Insomnia Scale score of 6 points or higher. The secondary outcomes included postoperative anxiety and depression scores using the Hospital Anxiety and Depression Scale, postoperative pain using the visual analog scale, postoperative hydromorphone consumption, and risk factors associated with PSD.

RESULTS

A total of 183 female patients were randomized to the control group (n = 91; median [IQR] age, 45 [35-49] years) and the esketamine group (n = 92; median [IQR] age, 43 [32-49] years). The incidence of PSD in the esketamine group was significantly lower than in the control group on POD 1 (22.8% vs 44.0%; odds ratio [OR], 0.38 [95% CI, 0.20-0.72]; P = .002) and POD 3 (7.6% vs 19.8%; OR, 0.33 [95% CI, 0.13-0.84]; P = .02). There were no differences in postoperative depression and anxiety scores between the 2 groups. Postoperative hydromorphone consumption in the first 24 hours (3.0 [range, 2.8-3.3] mg vs 3.2 [range, 2.9-3.4] mg; P = .04) and pain scores on movement (3 [3-4] vs 4 [3-5] points; P < .001) were significantly lower in the esketamine group than in the control group. On multivariable logistic regression, preoperative depression (OR, 1.31; 95% CI, 1.01-1.70) and anxiety (OR, 1.67; 95% CI, 1.04-1.80) scores, duration of anesthesia (OR, 1.04; 95% CI, 1.00-1.08), and postoperative pain score (OR, 1.92; 95% CI, 1.24-2.96) were identified as risk factors associated with PSD.

CONCLUSIONS AND RELEVANCE

Results of this trial showed the prophylactic effect of intraoperative esketamine infusion on the incidence of PSD in patients who underwent gynecological laparoscopic surgery. Further studies are needed to confirm these results.

TRIAL REGISTRATION

Chinese Clinical Trial Registry Identifier: ChiCTR2100048587.

The Impact of Sleep Disturbance on Gut Microbiota, Atrial Substrate, and Atrial Fibrillation Inducibility in Mice: A Multi-Omics Analysis

This study examined the effect of sleep disturbance on gut microbiota (GM), atrial substrate, and atrial fibrillation (AF) inducibility. C57BL/6 mice were subjected to six weeks of sleep deprivation (SD) using the method of modified multiple-platform. Transesophageal burst pacing was performed to evaluate AF inducibility. Feces, plasma, and an atrium were collected and analyzed by 16s rRNA sequencing, liquid chromatography−mass spectrometry (LC-MS)-based metabolome, histological studies, and transcriptome. Higher AF inducibility (2/30 of control vs. 15/30 of SD, p = 0.001) and longer AF duration (p < 0.001), concomitant with aggravated fibrosis, collagen, and lipid accumulation, were seen in the SD mice compared to control mice. Meanwhile, elevated alpha diversity, higher abundance of Flavonifractor, Ruminococcus, and Alloprevotella, as well as imbalanced functional pathways, were observed in the gut of SD mice. Moreover, the global patterns for the plasma metabolome were altered, e.g., the decreased butanoate metabolism intermediates in SD mice. In addition, disrupted metabolic homeostasis in the SD atrium, such as fatty acid metabolism, was analyzed by the transcriptome. These results demonstrated that the crosstalk between GM and atrial metabolism might be a promising target for SD-mediated AF susceptibility.

Mitigation of perioperative neurocognitive disorders: A holistic approach

William Morton introduced the world to ether anesthesia for use during surgery in the Bullfinch Building of the Massachusetts General Hospital on October 16, 1846. For nearly two centuries, the prevailing wisdom had been that the effects of general anesthetics were rapidly and fully reversible, with no apparent long-term adverse sequelae. Despite occasional concerns of a possible association between surgery and anesthesia with dementia since 1887 (Savage, 1887), our initial belief was robustly punctured following the publication in 1998 of the International Study of Post-Operative Cognitive Dysfunction [ISPOCD 1] study by Moller et al. (1998) in The Lancet, in which they demonstrated in a prospective fashion that there were in fact persistent adverse effects on neurocognitive function up to 3 months following surgery and that these effects were common. Since the publication of that landmark study, significant strides have been made in redefining the terminology describing cognitive dysfunction, identifying those patients most at risk, and establishing the underlying etiology of the condition, particularly with respect to the relative contributions of anesthesia and surgery. In 2018, the International Nomenclature Consensus Working Group proposed new nomenclature to standardize identification of and classify perioperative cognitive changes under the umbrella of perioperative neurocognitive disorders (PND) (Evered et al., 2018a). Since then, the new nomenclature has tried to describe post-surgical cognitive derangements within a unifying framework and has brought to light the need to standardize methodology in clinical studies and motivate such studies with hypotheses of PND pathogenesis. In this narrative review, we highlight the relevant literature regarding recent key developments in PND identification and management throughout the perioperative period. We provide an overview of the new nomenclature and its implications for interpreting risk factors identified by clinical association studies. We then describe current hypotheses for PND development, using data from clinical association studies and neurophysiologic data where appropriate. Finally, we offer broad clinical guidelines for mitigating PND in the perioperative period, highlighting the role of Brain Enhanced Recovery After Surgery (Brain-ERAS) protocols.

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.

Perioperative Brain Health in the Older Adult: A Patient Safety Imperative

While people 65 years of age and older represent 16% of the population in the United States, they account for >40% of surgical procedures performed each year. Maintaining brain health after anesthesia and surgery is not only important to our patients, but it is also an increasingly important patient safety imperative for the specialty of anesthesiology. Aging is a complex process that diminishes the reserve of every organ system and often results in a patient who is vulnerable to the stress of surgery. The brain is no exception, and many older patients present with preoperative cognitive impairment that is undiagnosed. As we age, a number of changes occur in the human brain, resulting in a patient who is less resilient to perioperative stress, making older adults more susceptible to the phenotypic expression of perioperative neurocognitive disorders. This review summarizes the current scientific and clinical understanding of perioperative neurocognitive disorders and recommends patient-centered, age-focused interventions that can better mitigate risk, prevent harm, and improve outcomes for our patients. Finally, it discusses the emerging topic of sleep and cognitive health and other future frontiers of scientific inquiry that might inform clinical best practices.

Melatonin and Its Analogs for Prevention of Post-cardiac Surgery Delirium: A Systematic Review and Meta-Analysis

Background

The effectiveness of melatonin and its analogs in preventing postoperative delirium (POD) following cardiac surgery is controversial. The purpose of this systematic review and meta-analysis was to confirm the benefits of melatonin and its analogs on delirium prevention in adults who underwent cardiac surgery.

Methods

We systematically searched the PubMed, Cochrane Library, Web of Science, Embase, and EBSCOhost databases, the last search was performed in October 2021 and repeated before publication. The controlled studies were included if investigated the impact of melatonin and its analogs on POD in adults who underwent cardiac surgery. The primary outcome was the incidence of delirium. The Stata statistical software 17.0 was used to perform this study.

Results

This meta-analysis included eight randomized controlled trials (RCTs) and two cohort studies with a total of 1,714 patients. The results showed that melatonin and ramelteon administration were associated with a significantly lower incidence of POD in adults who underwent cardiac surgery (odds ratio [OR], 0.46; 95% confidence interval [CI], 0.29–0.74; P = 0.001). The subgroup analyses confirmed that melatonin 3 mg (OR, 0.37; 95% CI, 0.18–0.76; P = 0.007) and 5 mg (OR, 0.34; 95% CI, 0.21–0.56; P < 0.001) significantly reduced the incidence of POD.

Conclusion

Melatonin at dosages of 5 and 3 mg considerably decreased the risk of delirium in adults who underwent cardiac surgery, according to our results. Cautious interpretation of our results is important owing to the modest number of studies included in this meta-analysis and the heterogeneity among them.

Systematic Review Registration

PROSPERO registration number: CRD42021246984.

Progress in Research on the Effect of Melatonin on Postoperative Cognitive Dysfunction in Older Patients

Postoperative cognitive dysfunction (POCD) is a common complication of the central nervous system in elderly patients after operation. It will prolong the length of stay, reduce the independence and quality of daily life, and increase the risk of death. However, at present, there is a lack of safe and effective ideal drugs for the prevention and treatment of POCD. Melatonin is one of the hormones secreted by the pineal gland of the brain, which has the functions of regulating circadian rhythm, anti-inflammation, anti-oxidation, anti-apoptosis, and so on. Some recent studies have shown that MT can prevent and treat POCD by adjusting circadian rhythm, restoring cholinergic system function, neuroprotection, and so on. This article will introduce POCD, melatonin and the mechanism of melatonin on POCD, respectively, to provide a basis for clinical prevention and treatment of POCD in the elderly.

Suvorexant with or without ramelteon to prevent delirium: a systematic review and meta-analysis

Delirium is a common and serious neurobehavioral syndrome, associated with prolonged hospital stays, and increased morbidity and mortality. As it remains unclear whether suvorexant with or without ramelteon prevents delirium in elderly hospitalized patients, we conducted a systematic review and meta-analysis to evaluate, searching the PubMed, Cochrane Library, Web of Science, EMBASE, and EBSCOhost databases for all randomized controlled trials (RCTs), case-control studies, and cohort studies that investigated the effects of suvorexant with or without ramelteon on delirium in adult hospitalized patients. The primary outcome was the incidence of delirium. Two randomized controlled trials, 7 cohort studies and 2 case-control studies involving 2594 patients were included in this meta-analysis. The results showed that both suvorexant alone (odds ratio (OR) = 0.30, 95% confidence interval (CI): 0.14-0.65, P = 0.002) and suvorexant with ramelteon (OR = 0.39, 95% CI 0.23-0.65, P = 0.0003) reduced the incidence of delirium in adult hospitalized patients. Six studies involved the use of benzodiazepines; subgroup analysis performed separately in the suvorexant alone and suvorexant with ramelteon groups indicated that when benzodiazepine was administered, suvorexant with ramelteon was effective at reducing the incidence of delirium (OR = 0.53, 95% CI 0.37-0.74, P = 0.0002), but no significant difference was observed for suvorexant alone (OR = 0.40, 95% CI 0.11-1.53, P = 0.18). The current literature thus supports the effectiveness of suvorexant with or without ramelteon for delirium prevention, although suvorexant alone failed to significantly reduce the incidence of delirium when benzodiazepine was administered. The present study was limited by the significant heterogeneity among the included studies, and caution should be exercised when interpreting the results. This study was registered in the PROSPERO database (CRD4202017964).

Effects of Melatonin Treatment on Perioperative Sleep Quality: A Systematic Review and Meta-Analysis with Trial Sequential Analysis of Randomized Controlled Trials

PURPOSE

Perioperative sleep disorders have attracted much attention due to their high prevalence and severe harm, and the current treatment methods are insufficient. Some randomized controlled trials (RCTs) have produced controversial results on whether melatonin can improve perioperative sleep quality. This review aimed to evaluate the effects of melatonin treatment on perioperative sleep quality.

PATIENTS AND METHODS

A systematic search of six databases was performed to identify RCTs investigating melatonin and perioperative sleep. The outcomes analyzed were subjective sleep quality, sleep latency (SL), total sleep time (TST), sleep efficiency (SE), the behavior of awakenings and daily naps, and the incidence of poor sleep quality. RevMan 5.4 and Stata 16 software was used for the meta-analysis and sensitivity analysis, and trial sequential analysis was conducted using TSA 0.9.5.10 Beta software. This study was registered in PROSPERO (registration number: CRD42022311378).

RESULTS

10 studies containing 725 participants were included. Melatonin improved postoperative subjective sleep quality (SMD: -0.30; 95% CI: [-0.47, -0.14]; P = 0.0004) but not preoperative sleep quality (MD: -2.76; 95% CI: [-10.44, 4.91]; P = 0.48). In the postoperative period, 6mg dose had the best efficacy (SMD: -0.31; 95% CI: [-0.57, -0.04]; P = 0.02). Melatonin increased postoperative TST (P = 0.02) and SE (P = 0.002) and decreased the incidence of postoperative poor sleep quality (P = 0.002) but had no effect on SL (P = 0.11), the number and duration of awakenings (P = 0.28; P=0.55), and the number and duration of daily naps (P = 0.26; P = 0.38). The trial sequential analysis showed that the accumulated Z value crossed both the traditional boundary value and the TSA boundary value, further confirming the stability of the result of the meta-analysis.

CONCLUSION

Melatonin treatment can improve postoperative sleep quality. A 6mg daily dose of melatonin may have a better beneficial effect, which needs further exploration. This study supports the application of melatonin for improving postoperative sleep quality.