Promoting sleep and circadian health may prevent postoperative delirium: A systematic review and meta-analysis of randomized clinical trials

Protocol and design of the REPOSE study: a double-blinded, randomised, placebo-controlled trial to evaluate the efficacy of suvorexant to improve postoperative sleep and reduce delirium severity in older patients undergoing non-cardiac surgery

INTRODUCTION

Postoperative delirium occurs in up to 40% of older surgical patients and has been associated with prolonged hospital stays, long-term cognitive impairment and increased 1-year postoperative mortality. Postoperative sleep disturbances may increase the risk of delirium, but studies investigating pharmacotherapies to improve postoperative sleep to prevent delirium remain limited. Suvorexant is a selective antagonist of orexin 1 and 2 receptors and is approved for insomnia pharmacotherapy by the Food and Drug Administration. It has the potential to improve postoperative sleep and reduce postoperative delirium rates, but randomised controlled trials (RCTs) are needed to determine the efficacy of postoperative suvorexant administration. The REPOSE study (reducing delirium by enhancing postoperative sleep with suvorexant) is a single-centre, randomised, double-blinded RCT that aims to evaluate the efficacy of suvorexant in increasing total sleep time (TST) and decreasing delirium severity in older patients undergoing non-cardiac surgery.

METHODS AND ANALYSIS

REPOSE will enroll 130 patients (aged ≥65 years) undergoing non-cardiac surgery with a planned postoperative inpatient stay. Participants will be randomised to receive 20 mg oral suvorexant or placebo nightly on postoperative nights 0, 1 and 2. The primary endpoint is TST on the first postoperative night, as measured using an electroencephalography headband. The secondary endpoint is peak postoperative delirium severity as measured by the 3-minute diagnostic interview for the confusion assessment method severity scores. Primary endpoint data will be analysed with a two-sample t-test using an intent-to-treat approach to compare TST on the first night that a patient received a study drug dose. Secondary and exploratory endpoint data will be analysed using two-sample t-tests between groups.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the Duke Institutional Review Board (protocol #00111869). Results of the REPOSE study will be published in a peer-reviewed journal and presented at academic conferences. Trial data will be deposited in ClinicalTrials.gov.

TRIAL REGISTRATION NUMBER

NCT05733286.

Effects of Sensory-Based Interventions on Delirium Prevention in Critically Ill Patients: A Systematic Review and Meta-Analysis

OBJECTIVE

To identify, appraise and synthesize current evidence on different sensory-based interventions on delirium prevention in critically ill patients.

DATA SOURCES

A comprehensive electronic literature search was performed in the PubMed, Embase, Cumulative Index of Nursing and Allied Health Literature, Cochrane Library, China Biology Medicine, China National Knowledge Infrastructure, Wanfang and WeiPu databases from inception to 2 June 2022. The data were updated on 24 December 2022. The study was registered on PROSPERO (CRD 42021254328).

REVIEW METHODS

Randomized controlled trials were included. Participants in the included studies were critically ill patients aged 18 years or older, and the interventions involved care by sensory-based intervention. And the outcome was the incidence of delirium rated by the Confusion Assessment Method for the ICU Tool.

RESULTS

The 14 studies included in the systematic review indicated a reduction in the effectiveness of sensory-based intervention on the incidence of delirium. Subgroup analyses showed significant effects for auditory stimulation (OR, 0.46; 95% confidence interval [CI], 0.27-0.79; p = 0.005) and tactile stimulation (OR, 0.53; 95% CI, 0.33-0.87; p = 0.01) but not for the effectiveness of visual intervention on the incidence of delirium (OR, 0.71; 95% CI, 0.38-1.30; p = 0.27).

CONCLUSIONS

Sensory-based interventions significantly reduce the incidence of delirium in critical patients. It is suggested that when choosing sensory-based interventions, auditory intervention should be preferred.

The Impact of Non-Pharmacological Sleep Interventions on Delirium Prevention and Sleep Improvement in Postoperative ICU Patients: A Systematic Review and Network Meta-Analysis

OBJECTIVES

Analyze the effectiveness of different non-pharmacological sleep interventions in preventing delirium among postoperative ICU patients.

RESEARCH METHODOLOGY

We conducted a comprehensive search on PubMed, Cochrane Library, Web of Science, Embase, CINAHL, OpenGrey and reference lists up to May 2024.

SETTING

We systematically searched all randomized controlled trials related to non-pharmacological sleep interventions for the prevention of delirium.

RESULTS

The results of the network meta-analysis showed that, compared to Usual Care, multicomponent interventions are the most effective measures for preventing delirium in postoperative ICU patients (RR = 0.32, 95 % CI = 0.20 to 0.51). This is followed by non-pharmacological sleep interventions aimed at stress relief (RR = 0.60, 95 % CI = 0.41 to 0.89) and circadian rhythm (RR = 0.61, 95 % CI = 0.39 to 0.96). Additionally, non-pharmacological sleep interventions focusing on circadian rhythm demonstrated an improvement in sleep quality among postoperative ICU patients (SMD = -0.99, 95 % CI = -1.88 to -0.11).

CONCLUSIONS

Our study found that multicomponent non-pharmacological sleep interventions are effective in reducing the incidence of delirium in postoperative ICU patients. Furthermore, non-pharmacological interventions focused on circadian rhythm regulation significantly enhance sleep quality among these patients.

IMPLICATIONS FOR CLINICAL PRACTICE

Based on this study, intensive care units and nursing staff have an opportunity to implement the most effective non-pharmacological sleep interventions to prevent delirium and improve sleep quality in postoperative ICU patients. This could contribute to a reduction in the incidence of delirium in postoperative ICU patients.

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.

Low-dose clonidine infusion to improve sleep in postoperative patients in the high-dependency unit. A randomised placebo-controlled single-centre trial

PURPOSE

Dexmedetomidine increases sleep and reduces delirium in postoperative patients, but it is expensive and requires a monitored environment. Clonidine, another α 2-agonist, is cheaper and is used safely for other purposes in wards. We assessed whether clonidine would improve sleep in postoperative high-dependency unit (HDU) patients.

METHODS

The Clonidine at Low dosage postoperatively to Nocturnally Enhance Sleep (CLONES) study was a double-blind, placebo-controlled, parallel-group pilot effectiveness randomised trial involving adult elective surgery HDU patients in a single academic hospital. Patients received clonidine 0.3 μg/kg/h or saline placebo on the night of surgery. The primary outcome was total sleep time measured using a consumer actigraphy/photoplethysmography device.

RESULTS

Of the 83 randomised patients, three had no data available, leaving 80 (39 clonidine, 41 placebo) in the intention-to-treat analysis, modified for missing data. Median patient ages of the groups were similar (61 and 59 years), as were other baseline characteristics. Clonidine patients had a mean of 100.8 (95% confidence interval [CI] 38.2-163.4) minutes (p = 0.002) longer total sleep time (mean 497.2 vs. 396.4 min) and reported better sleep overall. Delirium was only observed in one patient prior to study drug infusion, and none at the end of the study. Safety outcomes were not different. Four clonidine patients had their medication ceased due to bradycardia and hypotension that required no additional treatment.

CONCLUSION

Among postoperative elective surgical patients admitted to HDU, low-dose non-titrated clonidine, compared to placebo, was associated with longer and subjectively better-quality sleep.

Effect of obstructive sleep apnea on postoperative delirium: a system review and meta-analysis

PURPOSE

To investigate the impact of obstructive sleep apnea (OSA) on postoperative delirium (PD), and evaluate the effectiveness of positive airway pressure (PAP) therapy on PD among OSA patients.

METHODS

We systematically searched Embase, Cochrane Library and PubMed databases from their establishment to November 27, 2022. A random-effects approach was employed to determine aggregated results. Subgroup and sensitivity analyses were carried out to investigate heterogeneity.

RESULTS

Sixteen eligible studies were included in the analysis. Thirteen studies revealed that OSA significantly elevated the likelihood of developing PD (OR = 1.71; 95%CI = 1.17 to 2.49; p = 0.005). Subgroup analysis according to delirium assessment scales showed that OSA did not exhibit an association with the incidence of PD assessed by the Confusion Assessment Method-Intensive Care Unit (OR = 1.14; 95%CI = 0.77 to 1.67; p = 0.51) but enhanced the likelihood of developing PD evaluated with other measurement scales (OR = 2.15; 95%CI = 1.44 to 3.19; p = 0.0002). Three additional studies explored the impact of PAP treatment on PD among OSA individuals, indicating no significant reduction in PD incidence with PAP use (OR = 0.58; 95%CI = 0.13 to 2.47; p = 0.46).

CONCLUSIONS

OSA may not be a risk factor for PD in critically ill patients in the intensive care unit, but may increase the likelihood of developing PD among individuals receiving regular care in the ward postoperatively. The efficacy of PAP therapy in decreasing PD incidence among OSA patients remains debatable.

Effect of intra-operative Magnesium sulphate on the occurrence of post-operative delirium and insomnia in patients undergoing lumbar fixation: a randomized controlled trial

BACKGROUND

Over the last two decades, a large body of literature has focused on studying the prevalence and outcome of the postoperative delirium and sleep disturbance. The aim of this work was to evaluate the effect of intraoperative administration of Magnesium sulphate on the occurrence of post-operative delirium and insomnia in patients undergoing lumbar fixation.

METHODS

This prospective randomized controlled trial was carried out on 80 patients indicated for lumbar fixation; 40 of them received conventional general anesthesia with extra administration of intraoperative magnesium sulphate (Mg sulphate group), and the other 40 received conventional general anesthesia only (control group). Both groups were submitted to pre-operative assessment of depression using Beck Depression inventory (BDI) scale, pre-operative assessment of fatigue using a fatigue questionnaire, pre- and post-operative assessment of insomnia using Insomnia severity index (ISI), post-operative assessment of delirium using Memorial delirium assessment scale (MDAS), post-operative assessment of pain using Visual Analogue Scale (VAS), and pre- and post-operative Quantitative electroencephalography (QEEG).

RESULTS

Mg sulphate administration, age, pre-operative BDI, pre-operative ISI, and post-operative VAS were independent predictors of post-operative ISI (P-value < 0.001, 0.047, 0.021, < 0.001, and < 0.001 respectively). Age and post-operative VAS were independent predictors of post-operative MDAS (P-value = 0.008, 0.013 respectively). Mg sulphate administration and pre-operative ISI were independent predictors of post-operative VAS (P-value = 0.010, 0.006 respectively).

CONCLUSION

There was a significant relationship between intraoperative Mg sulphate administration and both post-operative insomnia and pain in unadjusted and adjusted analysis.

Effects of Intranasal Insulin Pretreatment on Preoperative Sleep Quality and Postoperative Delirium in Patients Undergoing Valve Replacement for Rheumatic Heart Disease

Background

Postoperative delirium (POD) is a common neurological complication associated with valve replacement. Preoperative sleep disturbance is a risk factor for POD development, and nasal insulin modulates the sleep-wake cycle. This study investigated the beneficial effects of intranasal insulin pretreatment on preoperative sleep quality and reducing POD in patients undergoing valve replacement for rheumatic heart disease.

Patients and Methods

This prospective, single-center, randomized controlled trial (RCT) included 76 adult patients aged 18-65 years undergoing valve surgery with cardiopulmonary bypass who were randomly allocated to receive intranasal insulin or normal saline interventions two days before surgery. POD incidence was on postoperative days 1 (T3), 2 (T4), and 3 (T5). Before the first intervention (T0), 1 d before surgery (T1), and before anesthesia on the day of surgery (T2), sleep quality was assessed and serum cortisol concentrations were measured. At T1 and T2, sleep quality related indicators monitored by sleep monitoring watches from the previous night were recorded.

Results

Compared with the normal saline group, 3 days after surgery, the insulin group showed a significantly reduced incidence of POD; significantly increased deep sleep, REM sleep, deep sleep continuity, and total sleep quality scores at T1 and T2; and significantly reduced serum cortisol concentration, PSQI scale, light sleep ratio, and wakefulness at T1 and T2.

Conclusion

The administration of 20 U of intranasal insulin twice daily, from 2 days preoperatively until 10 minutes preanesthesia on the day of surgery, can improved preoperative sleep quality significantly and reduced POD incidence in patients with rheumatic heart disease undergoing valve replacement.

Clinical Trial Registration

This study was registered with the Chinese Clinical Trial Registry (www.chictr.org.cn, with the unique identifier ChiCTR2100048515; July 9, 2021).

Melatonin regulates the circadian rhythm to ameliorate postoperative sleep disorder and neurobehavioral abnormalities in aged mice

BACKGROUND

Postoperative sleep disorder (PSD) and delirium, which may be associated with surgery and inhalational anesthetics, induce adverse effects in old adults. Emerging evidence indicates that circadian rhythm contributes to various neuropathological diseases, including Alzheimer's disease. Thus, we analyzed the potential role of circadian rhythm in PSD and delirium-like behavior in aged mice and determined whether exogenous melatonin could facilitate entrainment of the circadian rhythm after laparotomy under sevoflurane anesthesia.

METHODS

We selected old C57BL/6J mice which receiving laparotomy/sevoflurane anesthesia as model animals. We employed buried food, open field, and Y maze test to assess delirium-like behavior, and electroencephalography/electromyography (EEG/EMG) were used to investigate sleep changes. We analyzed the transcription rhythm of clock genes in superchiasmatic nucleus (SCN) to explore the effects of surgery and melatonin pretreatment on the circadian rhythm. Then, we measured melatonin receptor levels in SCN and ERK/CREB pathway-related proteins in hippocampus and prefrontal cortex to assess their role in PSDs and delirium-like behavior.

RESULTS

Laparotomy under sevoflurane anesthesia had a greater influence than sevoflurane alone, leading to sleep disorder, a shift in sleep-wake rhythm, and delirium-like behavior. Bmal1, Clock, and Cry1 mRNA expression showed a peak shift, MT1 melatonin receptor expression level was increased in the SCN, and p-ERK/ERK and p-CREB/CREB were decreased in hippocampus and prefrontal cortex of aged mice 1 day after laparotomy. Melatonin showed significant efficacy in ameliorating PSD and delirium-like behavior and restoring the circadian rhythm, reversing melatonin receptor and ERK/CREB pathway expression abnormalities. In addition, most of the beneficial effect of melatonin was antagonized by luzindole, a melatonin receptor antagonist.

CONCLUSIONS

Melatonin receptors in SCN, circadian rhythm, and ERK/CREB signaling pathway participate in the pathophysiological processes of PSD and delirium-like behavior. Melatonin intervention could be a potential preventative approach for PSD and delirium.

Incidence, associated factors, and outcomes of delirium in critically ill children in china: a prospective cohort study

BACKGROUND

Delirium occurs frequently in critically ill children and has been reported in many countries, but delirium is not well-characterized in China. The aim of this study was to represent the incidence of delirium in critically ill children in China, its associated factors, and the influence of delirium on in-hospital outcomes.

METHODS

This observational prospective cohort study was set up in a large academic medical center with a 57-bed PICU in southwestern China. Critically ill children who required PICU stays over 24 h and were admitted between November 2019 and February 2022 were included in this study. The Cornell Assessment of Pediatric Delirium was used twice daily for delirium evaluation by bedside nurses, and twenty-four clinical features were collected from medical and nursing records during hospitalization.

RESULTS

The incidence of delirium was 26.0% (n = 410/1576). Multivariate analysis revealed that seven independent risk factors including days of mechanical ventilation and physical restraints, admission diagnosis (neurologic disorder), sleep deprivation, use of benzodiazepines and dexmedetomidine, liver failure/liver dysfunction associated with delirium in critically ill children. One potentially protective factor was the watching television /listening to music/playing with toys. Children with delirium had longer lengths of stay in the PICU (median 11 vs. 10 days, p < 0.001) and hospital (median 18 vs. 15 days, p < 0.001) compared to those without delirium. Additionally, the in-hospital mortality rates were 4.63% and 0.77% in patients with and without delirium (p < 0.05).

CONCLUSIONS

Delirium is common in critically ill children in China and related to poor outcomes. Interventional studies are warranted to determine the best practices to reduce delirium exposure in at-risk children.

Circadian Rest-Activity Rhythms, Delirium Risk, and Progression to Dementia

OBJECTIVE

Delirium is a complex neurocognitive syndrome suspected to be bidirectionally linked to dementia. Circadian rhythm disturbances likely contribute to dementia pathogenesis, but whether these disturbances are related to delirium risk and progression to all-cause dementia is unknown.

METHODS

We analyzed continuous actigraphy data from 53,417 middle-aged or older UK Biobank participants during a median 5 years of follow-up. Four measures were used to characterize the 24-hour daily rest-activity rhythms (RARs): normalized amplitude, acrophase representing the peak activity time, interdaily stability, and intradaily variability (IV) for fragmentation of the rhythm. Cox proportional hazards models examined whether RARs predicted incident delirium (n = 551) and progression to dementia (n = 61).

RESULTS

Suppressed 24-hour amplitude, lowest (Q1) versus highest (Q4) quartile (hazard ratio [HR]Q1 vs Q4 = 1.94, 95% confidence interval [CI] = 1.53-2.46, p < 0.001), and more fragmented (higher IV: HRQ4 vs Q1 = 1.49, 95% CI = 1.18-1.88, p < 0.001) rhythms predicted higher delirium risk, after adjusting for age, sex, education, cognitive performance, sleep duration/disturbances, and comorbidities. In those free from dementia, each hour of delayed acrophase was associated with delirium risk (HR = 1.13, 95% CI = 1.04-1.23, p = 0.003). Suppressed 24-hour amplitude was associated with increased risk of progression from delirium to new onset dementia (HR = 1.31, 95% CI = 1.03-1.67, p = 0.03 for each 1-standard deviation decrease).

INTERPRETATION

Twenty-four-hour daily RAR suppression, fragmentation, and potentially delayed acrophase were associated with delirium risk. Subsequent progression to dementia was more likely in delirium cases with suppressed rhythms. The presence of RAR disturbances before delirium and prior to progression to dementia suggests that these disturbances may predict higher risk and be involved in early disease pathogenesis. ANN NEUROL 2023;93:1145-1157.

Promoting sleep in hospitals: An integrative review of nurses' attitudes, knowledge and practices

AIMS

To explore nurses' knowledge, attitudes and practices related to improving hospitalized patients' sleep.

DESIGN

Integrative review.

DATA SOURCES

We searched CINAHL, PubMed and PsycInfo electronically including a manual search of references listed within the relevant studies. Original, peer-reviewed studies published in English between 2000 and 2022 evaluating nurses' sleep knowledge, attitudes, or practices to improve inpatients' sleep were reviewed.

REVIEW METHODS

This review was guided by Whittemore and Knafl method and followed PRISMA guidelines to search the literature. Fifteen articles reporting nurses' sleep knowledge, attitudes or practices to improve inpatients' sleep were included. The quality appraisal was done using the Mixed Methods Appraisal Tool version 2018.

RESULTS

Inadequate training of nurses regarding sleep hygiene and insufficiency in sleep-promoting practices were apparent. Most studies reported that nurses hold positive attitudes about sleep. The acuity of patients' health conditions affected their perception of sleep priorities. Lack of organizational sleep policies/protocols and coworkers' attitudes negatively impacted nurses' motivation to implement sleep hygiene interventions. Interventions reported in the studies were reducing noise and nursing interventions at night, using a clock for time orientation, earplugs, reducing light, keeping patients awake during the daytime, maintaining comfortable room temperature and managing patients' stress. These practices were hindered by poor knowledge, negative attitudes, patients' acuity and lack of sleep assessment tools.

CONCLUSION

It is essential to support nursing practice to improve patients' sleep in hospitals through interventions that target nurses' knowledge, attitudes and confidence towards implementing sleep hygiene interventions to improve patients' sleep and, consequently, their health outcomes during hospitalization.

IMPACT

This integrative review explored nurses' knowledge, attitudes and practices to improve patients' sleep during hospitalization. It revealed that expanding nurses' sleep knowledge and empowering them to implement sleep promotion practices are needed. Nursing educators and leaders need to be involved.

NO PATIENT OR PUBLIC CONTRIBUTION

This paper is an integrative review and does not include patient or public contribution.

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.

Society of Anesthesia and Sleep Medicine Position Paper on Patient Sleep During Hospitalization

This article addresses the issue of patient sleep during hospitalization, which the Society of Anesthesia and Sleep Medicine believes merits wider consideration by health authorities than it has received to date. Adequate sleep is fundamental to health and well-being, and insufficiencies in its duration, quality, or timing have adverse effects that are acutely evident. These include cardiovascular dysfunction, impaired ventilatory function, cognitive impairment, increased pain perception, psychomotor disturbance (including increased fall risk), psychological disturbance (including anxiety and depression), metabolic dysfunction (including increased insulin resistance and catabolic propensity), and immune dysfunction and proinflammatory effects (increasing infection risk and pain generation). All these changes negatively impact health status and are counterproductive to recovery from illness and operation. Hospitalization challenges sleep in a variety of ways. These challenges include environmental factors such as noise, bright light, and overnight awakenings for observations, interventions, and transfers; physiological factors such as pain, dyspnea, bowel or urinary dysfunction, or discomfort from therapeutic devices; psychological factors such as stress and anxiety; care-related factors including medications or medication withdrawal; and preexisting sleep disorders that may not be recognized or adequately managed. Many of these challenges appear readily addressable. The key to doing so is to give sleep greater priority, with attention directed at ensuring that patients' sleep needs are recognized and met, both within the hospital and beyond. Requirements include staff education, creation of protocols to enhance the prospect of sleep needs being addressed, and improvement in hospital design to mitigate environmental disturbances. Hospitals and health care providers have a duty to provide, to the greatest extent possible, appropriate preconditions for healing. Accumulating evidence suggests that these preconditions include adequate patient sleep duration and quality. The Society of Anesthesia and Sleep Medicine calls for systematic changes in the approach of hospital leadership and staff to this issue. Measures required include incorporation of optimization of patient sleep into the objectives of perioperative and general patient care guidelines. These steps should be complemented by further research into the impact of hospitalization on sleep, the effects of poor sleep on health outcomes after hospitalization, and assessment of interventions to improve it.

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.

Effects of nonpharmacological interventions on sleep improvement and delirium prevention in critically ill patients: A systematic review and meta-analysis

OBJECTIVE

Sleep disturbance and delirium are common problems experienced by critically ill patients in the intensive care unit (ICU). These interrelated issues increase the length of stay in the ICU but might also negatively affect long-term health outcomes. The objective of this study was to identify the nonpharmacological interventions provided to improve sleep or prevent delirium in ICU patients or both and integrate their effect sizes.

REVIEW METHODS

This study was a registered systematic review and meta-analysis. We searched MEDLINE, CINAHL, EMBASE, Web of Science, and Cochrane Library from their inception until December 2021. We included randomised controlled trials and nonrandomised controlled trials-(RCT) that provided nonpharmacological interventions and reported sleep or delirium as outcome variables. Studies not published in English or whose full text was not available were excluded. The quality of the evidence was assessed with version 2 of the Cochrane risk-of-bias tool for RCTs and the Risk Of Bias In Non-randomised Studies of Interventions (ROBINS-I).

RESULTS

The systematic review included 118 studies, and the meta-analysis included 100 studies. Overall nonpharmacological interventions had significant effects on subjective sleep quality (standardised mean difference = 0.30, 95% confidence interval [CI] = 0.05 to 0.56), delirium incidence (odds ratio = 0.62, 95% CI = 0.53 to 0.73), and delirium duration (standardised mean difference = -0.68, 95% CI = -0.93 to -0.43). In individual interventions, aromatherapy, music, and massage effectively improved sleep. Exercise, family participation, information giving, cognitive stimulation, bright light therapy, architectural intervention, and bundles/protocols effectively reduced delirium. Light/noise blocking was the only intervention that ensured both sleep improvement and delirium prevention.

CONCLUSIONS

Our results suggest nonpharmacological interventions improve sleep and prevent delirium in ICU patients. We recommend that ICU nurses use nonpharmacological interventions that promote person-environment compatibility in their clinical practice. The results of our review can guide nurses in adopting interventions related to sleep and delirium.

PROSPERO REFERENCE NUMBER

CRD42021230815.

Transcutaneous Electrical Acupoint Stimulation Combined With Auricular Acupressure Reduces Postoperative Delirium Among Elderly Patients Following Major Abdominal Surgery: A Randomized Clinical Trial

Background

Postoperative delirium is common in elderly patients following major surgery. This study aimed to assess the effect of transcutaneous electrical acupoint stimulation combined with auricular acupressure on the incidence of postoperative delirium among older patients undergoing major abdominal surgery.

Methods

In this single-center, randomized controlled clinical trial, 210 patients aged 65 years or older undergoing major abdominal surgery were randomized to receive either intervention treatment (transcutaneous electrical acupoint stimulation started at 30 min before anesthesia until the end of the surgery, followed by intermittent auricular acupressure in the first three postoperative days; n = 105) or standard care (n = 105). The primary outcome was the incidence of delirium at the first seven postoperative days or until hospitalization depended on which came first. Secondary outcomes included delirium severity, opioid consumption, postoperative pain score, sleep quality, length of postoperative hospital stay, and postoperative 30-day complications. Enrollment was from April 2019 to March 2020, with follow-up ending in April 2020.

Results

All of the 210 randomized patients [median age, 69.5 years, 142 (67.6%) male] completed the trial. The incidence of postoperative delirium was significantly reduced in patients received intervention treatment (19/105 (18.1%) vs. 8/105 (7.6%), difference, –10.5% [95% CI, –1.5% to –19.4%]; hazard ratio, 0.41 [95% CI, 0.18 to 0.95]; P= 0.023). Patients in the control group had a higher postoperative Memorial Delirium Assessment Scale (4 vs. 3; difference, –1; 95% CI, –1 to 0; P = 0.014) and a greater increase in Pittsburgh Sleep Quality Index score from baseline to postoperative day three (2.5 vs. 2.0; difference, –1; 95% CI, –2 to –1; P &lt; 0.001) than patients in the intervention group. No significant difference was observed as of other secondary outcomes.

Conclusion

In elderly patients undergoing major abdominal surgery, transcutaneous electrical acupoint stimulation combined with auricular acupressure reduced the incidence of postoperative in-hospital delirium compared with standard care. A multicenter, randomized clinical trial with a larger sample size is necessary to verify these findings.

Clinical Trial Registration

[https://clinicaltrials.gov], identifier [NCT03726073].

Non-Pharmacological Interventions for Minimizing Physical Restraints Use in Intensive Care Units: An Umbrella Review

Background

There is a relationship between the application of physical restraints and negative physiological and psychological effects on critically ill patients. Many organizations have supported and advocated minimizing the use of physical restraints. However, it is still common practice in many countries to apply physical restraints to patients in intensive care.

Objective

This study aimed to assess the effectiveness of various non-pharmacological interventions used to minimize physical restraints in intensive care units and provide a supplement to the evidence summary for physical restraints guideline adaptation.

Methods

Based on the methodology of umbrella review, electronic databases, including Cochrane Database of Systematic Reviews, Joanna Briggs Institute Database of Systematic Reviews and Implementation Reports, MEDLINE, EMBASE, CINAHL, Web of Science, PsycInfo/Psyc Articles/Psychology and Behavioral Science Collection, China National Knowledge Infrastructure, SinoMed, and Wanfang Data, were searched to identify systematic reviews published from January 2016 to December 2020. Two independent reviewers undertook screening, data extraction, and quality appraisal. The methodological quality of systematic reviews was evaluated by AMSTAR 2. Evidence quality of each intervention was assessed according to GRADE. The corrected covered area was calculated as a measure of overlap.

Results

A total of 47 systematic reviews were included in the umbrella review, of which six were evaluated as high quality, five were of moderate quality, and the rest were of low or critically low quality. The corrected covered area range was from 0.0 to 0.269, which indicated that there was mild overlap between systematic reviews. The included systematic reviews evaluated various types of non-pharmacological interventions for minimizing physical restraints in intensive care units, which included multicomponent interventions involving healthcare professionals' education, family engagement/support, specific consultations and communication, rehabilitation and mobilization (rehabilitation techniques, early mobilization, inspiratory muscle training), interventions related to reducing the duration of mechanical ventilation (weaning modes or protocols, ventilator bundle or cough augmentation techniques, early tracheostomy, high-flow nasal cannula), and management of specific symptoms (delirium, agitation, pain, and sleep disturbances).

Conclusion

The number of systematic reviews related to physical restraints was limited. Multicomponent interventions involving healthcare professionals' education may be the most direct non-pharmacological intervention for minimizing physical restraints use in intensive care units. However, the quality of evidence was very low, and conclusions should be taken with caution. Policymakers should consider incorporating non-pharmacological interventions related to family engagement/support, specific consultations and communication, rehabilitation and mobilization, interventions related to reducing the duration of mechanical ventilation, and management of specific symptoms as part of the physical restraints minimization bundle. All the evidence contained in the umbrella review provides a supplement to the evidence summary for physical restraints guideline adaptation.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=242586, identifier: CRD42021242586.

Nocturnal dexmedetomidine alleviates post-intensive care syndrome following cardiac surgery: a prospective randomized controlled clinical trial

BACKGROUND

Dexmedetomidine is a sedative agent that may have the potential to reduce the risk of post-intensive care syndrome (PICS). This study aimed to establish whether prophylactic nocturnal dexmedetomidine safely reduces postoperative PICS incidence and to develop an easy-to-use model for predicting the risk of PICS following cardiac surgery.

METHODS

This was a single-center, double-blind, randomized, prospective, placebo-controlled trial. Patients undergoing cardiac surgery were randomly assigned (1:1) to dexmedetomidine or placebo (normal saline) groups between January 2019 and July 2020. Dexmedetomidine or a similar volume of saline was administered, with an infusion rate up to 1.2 μg/kg/h until the RASS remained between - 1 and 0. The primary study endpoint was PICS incidence at 6 months follow-up, as defined by cognitive, physical, or psychological impairments.

RESULTS

We assessed 703 individuals for eligibility, of whom 508 were enrolled. Of these, there were 251 in the dexmedetomidine group and 257 in the placebo group that received the trial agent, forming a modified intention-to-treat population. PICS incidence at 6-month follow-up was significantly decreased in the dexmedetomidine group (54/251, 21.5%) relative to the placebo group (80/257, 31.1%) (odds ratio [OR] 0.793, 95% CI 0.665-0.945; p = 0.014). Psychological impairment was significantly reduced in the dexmedetomidine group relative to the placebo group (18.7% vs. 26.8%, OR 0.806, CI 0.672-0.967, p = 0.029). However, dexmedetomidine treatment was associated with a higher rate of hypotension. A nomogram revealed that age, education, a medical history of diabetes and smoking, dexmedetomidine treatment, postoperative atrial fibrillation, and sequential organ failure assessment scores at 8 h post-surgery were independent predictors of PICS.

CONCLUSIONS

Prophylactic nocturnal dexmedetomidine administration significantly reduced PICS incidence by a marked reduction in psychological impairment within a 6-month follow-up period.

TRIAL REGISTRATION

ChiCTR, ChiCTR1800014314 . Registered 5 January 2018, http://www.chictr.org.cn/index.aspx.

Melatonin and melatonin-receptor agonists to prevent delirium in hospitalized older adults: An umbrella review

BACKGROUND

Alterations in circadian rhythm play an important role in the development of delirium. In this umbrella review, we examined the efficacy of melatonin and ramelteon for delirium prevention in hospitalized older adults.

METHODS

Umbrella review methodology from the Joanna Briggs Institute guided the review process. Only meta-analyses were included. Risk of bias was evaluated using the AMSTAR-2 checklist.

RESULTS

Three meta-analyses were included in this review. The quality of studies was low-to-moderate. Two meta-analyses reported a significant reduction in delirium using melatonin or ramelteon (pooled OR and 95% confidence intervals ranged from 0.41 [0.19-0.86] to 0.63 [0.46-0.87]). Melatonergics significantly reduced delirium on medical units (OR = 0.25, 95% CI 0.07-0.88) but not surgical units (OR = 0.62, 0.16-2.43). Heterogenity was high, with I2 ranging from 72.14% to 84%.

CONCLUSIONS

Melatonergics appear to prevent delirium among hospitalized older adults, particularly those on medical units. Based on these results, providers may consider using melatonergics as complements to high-quality multicomponent delirium prevention.

Are treatment effects consistent with hypothesized mechanisms of action proposed for postoperative delirium interventions? Reanalysis of systematic reviews

Aim: Postoperative delirium (POD) is associated with increased morbidity and is poorly understood. The aim of this review was to identify putative mechanisms through re-analysis of randomized trials on treatment or prevention of POD. Materials & methods: A systematic review was performed to identify systematic reviews of treatments for POD. Constituent randomized controlled trials were identified, and interventions were grouped according to hypothesized mechanisms of action. Effects were meta-analyzed by hypothesized mechanism and timing of intervention. Results: A total of 116 randomized controlled trials described 47 individual interventions for POD, with nine mechanisms identified. The largest effects were observed for postoperative inflammation reduction, and preoperative reinforcement of sleep-wake cycle. Conclusion: This approach identifies treatments focused on mechanisms of action that may be front runners for future trials and interventions.

Baseline sleep as a predictor of delirium after surgical aortic valve replacement: A feasibility study

OBJECTIVE

The goal is to assess the feasibility of conducting unattended (type II) sleep studies before surgical aortic valve replacement (SAVR) to examine the relationship between baseline sleep measures and postoperative delirium.

METHODS

This single-site study recruited 18 of 20 study referrals with aortic stenosis undergoing first lifetime SAVR. Subjects completed a home-based type II sleep study. Delirium was assessed postoperative days 1-5. Exact logistic regression was used to determine whether sleep efficiency or apnea/hypopnea index predicts delirium.

RESULTS

Of 18 study participants, 15 successfully completed a home sleep study (mean age: 71.7 +/- 8.1 years old; 10 male subjects). Five subjects (33.3%) developed delirium. Preliminary analyses found that greater sleep efficiency was associated with a large reduction in delirium odds but was not statistically significant (OR = 0.31, 95% CI: 0.06, 1.03, p = 0.057). The point estimate of the relationship between apnea/hypopnea index and delirium was not similarly sizeable (OR 1.10, 95% CI: 0.35, 3.37, p = 0.85).

CONCLUSIONS

Our findings suggest that home type II sleep studies before SAVR are feasible, and they support adequately powered studies investigating type II home sleep studies as a predictor of postoperative delirium and other important postsurgical outcomes.

Intensive Care Unit Environment and Sleep

Patients undergoing treatment in intensive care unit are in an extremely vulnerable state and require a complex multidisciplinary approach. Adequate sleep is required to maintain physiologic functions of the human body. Good sleep quality plays a vital role in the process of recovery. Sleep disruption in intensive care settings is a well-known fact. The consequences of sleep deprivation can cause numerous complications including delayed mechanical ventilation wean, neurocognitive dysfunction, decreased immune function and increased mortality rates. This review describes how the intensive care unit environment impacts sleep architecture.

Dexmedetomidine protects SH-SY5Y cells against MPP+ -induced declining of mitochondrial membrane potential and cell cycle deficits

Dexmedetomidine (Dex), an adrenergic α2 receptor agonist, is commonly used in deep-brain stimulation surgery for Parkinson's disease (PD). However, there is evidence that the use of anaesthetics may accelerate the progression of neurodegenerative diseases. The effect of Dex on PD remains unclear. Here, we cultured the all-trans-retinoicacid (ATRA) differentiated SH-SY5Y cells in vitro and then treated with MPP+ (1.5mM) with or without Dex (10nM) or Dex combined with Atipamezole (Ati,100nM, adrenergic α2 receptor inhibitor). The ratio of apoptotic cells, mitochondrial membrane potential (Δψm), reactive oxygen species (ROS), cell cycle and apoptotic markers (Cleaved caspase-3, 9) were analysed by flow cytometry and immunofluorescence. We found that the levels of apoptotic ratio and cleaved caspase-3, 9 increased, ROS accumulated, and mitochondrial membrane potential decreased after MPP+treatment, while these changes were partially reversed by Dex. Dex also prevented MPP+ induced cell arrest by increasing G1 phase cells, decreasing S phase cells, and decreasing the expression of cyclinD1 and Cdk4. Moreover the effects of Dex were partially reversed by Ati. These findings reveal that Dex attenuated MPP+ -induced apoptosis of SH-SY5Y cells by preventing the loss of Δψm, reducing ROS, and regulating the cell cycle. Our findings indicated that Dex is more likely to be a potential drug for the treatment of PD.

Effects of general versus regional anaesthesia on circadian melatonin rhythm and its association with postoperative delirium in elderly patients undergoing hip fracture surgery: study protocol for a prospective cohort clinical trial

INTRODUCTION

Postoperative delirium (POD) is a common neurological complication after hip fracture surgery and is associated with high morbidity and mortality in elderly patients. Although the specific mechanism of POD remains unclear, circadian rhythm disruptions have recently drawn increased attention. To date, only limited postoperative time points of plasma melatonin level measurements were recorded in previous studies, and such data cannot represent a comprehensive melatonin rhythm. The process of anaesthesia (either general anaesthesia (GA) or regional anaesthesia (RA)) is known to influence the melatonin rhythm. However, how these two anaesthesia methods differently affect the postoperative melatonin rhythm is still unknown. Therefore, we hypothesise that RA may attenuate the disruption of the melatonin rhythm, which might decrease the incidence of POD in elderly patients undergoing hip surgery.

METHODS AND ANALYSIS

In this prospective cohort clinical trial, 138 patients scheduled for hip fracture surgery will be divided into two groups to receive either GA or RA. The primary aim is to compare the circadian rhythm of melatonin secretion between the two groups and explore its association with the incidence of POD.

ETHICS AND DISSEMINATION

The study has been approved by the Medical Science Research Ethics Committees of Beijing Jishuitan Hospital (JLKS201901-04). The results of the study will be published in peer-reviewed international journals.

TRIAL REGISTRATION NUMBER

ChiCTR1900027393.

Delirium disorder

Objective

As the US population ages and with no definitive delirium treatments on the horizon, the delirium epidemic is on course to expand over the coming decades. Recognizing the import of this condition, a recent position statement from 10 medical societies—among whom the American Academy of Neurology was represented—issued recommendations on preferred nomenclature of delirium and acute encephalopathy: it concluded by preferring both terms. Urgently needed is an integrated model that addresses the near-total segregation of these separate bodies of literature, ideally one that offers an interdisciplinary framework to bring these 2 terms and those who use them together.

Methods

We review the historical forces that have led these terms to diverge and consider the unique benefits of each approach as well as their liabilities when considered in isolation. We then explore the potential implications of integrating these concepts and propose a hybrid model to capitalize on the strengths of both the model of delirium and that of acute encephalopathy.

Results

The model we propose—delirium disorder—builds on the recommendations of this recent position statement and provides a unifying framework designed to have clinical utility and interdisciplinary appeal. It also broadens the translational landscape by identifying 4 distinct treatment targets: underlying causes, procognitive factors, delirium (phenotype alone), and neurophysiologic targets.

Conclusions

This person-centered model aims to integrate delirium and acute encephalopathy within a single framework and shared nomenclature. It is hoped that this model aids in harmonizing research efforts and advancing clinical practice.

Study protocol for a prospective randomised double-blind placebo-controlled clinical trial investigating a Better Outcome with Melatonin compared to Placebo Administered to normalize sleep-wake cycle and treat hypoactive ICU Delirium: the Basel BOMP-AID study

INTRODUCTION

Delirium is frequently observed in the intensive care unit (ICU) population, in particular. Until today, there is no evidence for any reliable pharmacological intervention to treat delirium. The Basel BOMP-AID (Better Outcome with Melatonin compared to Placebo Administered to normalize sleep-wake cycle and treat hypoactive ICU Delirium) randomised trial targets improvement of hypoactive delirium therapy in critically ill patients and will be conducted as a counterpart to the Basel ProDex Study (Study Protocol, BMJ Open, July 2017) on hyperactive and mixed delirium. The aim of the BOMP-AID trial is to assess the superiority of melatonin to placebo for the treatment of hypoactive delirium in the ICU. The study hypothesis is based on the assumption that melatonin administered at night restores a normal circadian rhythm, and that restoration of a normal circadian rhythm will cure delirium.

METHODS AND ANALYSIS

The Basel BOMP-AID study is an investigator-initiated, single-centre, randomised controlled clinical trial for the treatment of hypoactive delirium with the once daily oral administration of melatonin 4 mg versus placebo in 190 critically ill patients. The primary outcome measure is delirium duration in 8-hour shifts. Secondary outcome measures include delirium-free days and death at 28 days after study inclusion, number of ventilator days, length of ICU and hospital stay, and sleep quality. Patients will be followed after 3 and 12 months for activities of daily living and mortality assessment. Sample size was calculated to demonstrate superiority of melatonin compared with placebo regarding the duration of delirium. Results will be presented using an intention-to-treat approach.

ETHICS AND DISSEMINATION

This study has been approved by the Ethics Committee of Northwestern and Central Switzerland and will be conducted in compliance with the protocol, the current version of the Declaration of Helsinki, the International Conference on Harmonisation (ICH) of technical requirements for registration of pharmaceuticals for human use; Good Clinical Practice (GCP) or ISO EN 14155 (as far as applicable), as well as all national legal and regulatory requirements. Study results will be presented in international conferences and published in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT03438526.

PROTOCOL VERSION

Clinical Study Protocol Version 3, 10.03.2019.

The pharmacotherapeutic management of postoperative delirium: an expert update

INTRODUCTION

Postoperative delirium is a common sequela in older adults in the peri-operative period leading to poor outcomes with a complex pathophysiology which has led to a variety of different pharmacologic agents employed in attempts to prevent and treat this syndrome. No pharmacologic agent has been approved to treat this disorder, but this review discusses the pharmacologic strategies which have been tried based on the hypotheses of the causation of the syndrome including neurotransmitter imbalance, inflammation, and oxidative stress.

AREAS COVERED

Systematic reviews and meta-analyses of randomized clinical trials (RCTs) were included via search of electronic databases specifically for the terms postoperative delirium and pharmacologic treatments. With this approach, the recurrent topics of analgesia and sedation, antipsychotics, acetylcholinesterase inhibitors (AchE-Is), inflammation, and melatonin were emphasized and provided the outline for this review.

EXPERT OPINION

Research evidence does not support any particular agent in any of the pharmacologic classes reviewed. However, there is some potential benefit with dexmedetomidine, melatonin, and the monitoring of anesthetic agents all of which need further clinical trials to validate these conclusions. Exploration of ways to improve studies and the application of novel pharmacologic agents may offer future benefit.

Perioperative Sleep Disturbances and Postoperative Delirium in Adult Patients: A Systematic Review and Meta-Analysis of Clinical Trials

Background: The aim of this systematic review and meta-analysis of clinical trials was to investigate the effects of perioperative sleep disturbances on postoperative delirium (POD). Methods: Authors searched for studies (until May 12, 2020) reporting POD in patients with sleep disturbances following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Results: We identified 29 relevant trials including 55,907 patients. We divided these trials into three groups according to study design: Seven retrospective observational trials, 12 prospective observational trials, and 10 randomized controlled trials. The results demonstrated that perioperative sleep disturbances were significantly associated with POD occurrence in observational groups [retrospective: OR = 0.56, 95% CI: [0.33, 0.93], I ² = 91%, p for effect = 0.03; prospective: OR = 0.27, 95% CI: [0.20, 0.36], I ² = 25%, p for effect < 0.001], but not in the randomized controlled trial group [OR = 0.58, 95% CI: [0.34, 1.01], I ² = 68%, p for effect = 0.05]. Publication bias was assessed using Egger's test. We used a one-by-one literature exclusion method to address high heterogeneity. Conclusions: Perioperative sleep disturbances were potential risk factors for POD in observational trials, but not in randomized controlled trials.