The relationship between obstructive sleep apnoea and postoperative delirium and pain: an observational study of a surgical cohort

The relationship between preoperative sleep disturbance and acute postoperative pain control: A systematic review and meta-analysis

Poor preoperative sleep quality and impaired sleep continuity may heighten acute postoperative pain intensity and increase analgesic consumption, with negative implications for recovery, mental and physical health. The main objective of the current review was to investigate the relationship between preoperative sleep disturbance and acute postoperative pain control. Four electronic databases were systematically searched from inception to December 2023. Two reviewers screened articles, extracted data, and assessed risk of bias for each included study. The search identified 26 prospective cohort studies and 3 retrospective cohort studies (16104 participants). Of the 29 included studies, 23 focused on preoperative insomnia symptoms, and three studies each focused on preoperative objective sleep continuity or sleep-disordered breathing. Meta-analysis, based on five studies with 1226 participants, showed that clinically significant preoperative insomnia symptoms were associated with moderate to severe pain intensity on the first postoperative day (odds ratio 2.69 (95 % confidence interval 2.03-3.57), p < 0.0001). Qualitative analysis showed relatively robust associations between preoperative insomnia symptoms, impaired sleep continuity and poorer acute, as well as subacute, postoperative pain control. Findings related to obstructive sleep apnea syndrome were mixed. Given that insomnia is a potentially modifiable risk factor, interventions targeting sleep prior to surgery may improve postoperative pain control.

Preoperative hypoxic biomarkers and postoperative delirium in patients with obstructive sleep apnea

PURPOSE

Postoperative delirium (POD) in patients with obstructive sleep apnea (OSA) is associated with increased mortality and healthcare costs. In this study, we investigated the association of OSA risk, serum biomarkers for central nervous ischemia (S100B and NSE), and POD.

METHODS

After research ethics approval, patients completed the STOP BANG assessment before undergoing elective surgery. Blood was drawn for S100B and NSE measurement, and cognitive performance was tested using the Montreal Cognitive Assessment (MoCA) at study admission and postoperatively at discharge. Delirium assessment was performed using the Nursing Delirium Screening Scale (NuDESC) and the Confusion Assessment Method (CAM).

RESULTS

One hundred twenty-four enrolled patients were separated into three OSA-risk groups based on STOP BANG score testing (low risk, n = 22; intermediate risk, n = 67; high risk, n = 35). Preoperative NSE values increased with OSA risk (NSE in ng/ml; mean [range]; low risk: 15.6 [9.2-44.3]; intermediate risk: 21.8 [7.6-114.1]; high risk: 29.2 [10.1-151]; p = 0.039). Postoperative MoCA and NuDESC assessments were not different between the OSA-risk groups. We found a decreasing incidence for POD with increasing OSA risk (positive CAM: low risk: 18.1%, intermediate risk: 12.0%; high risk: 11.5%, p = 0.043). However, this was no longer detectable in a complete case analysis. In patients with POD, postoperative ischemic biomarker values were not different between OSA-risk groups.

CONCLUSION

We found a trend of decreasing POD incidence with increasing OSA risk, which was not robust in a complete case analysis. Our results possibly support the phenomenon of hypoxic preconditioning.

The Role of Sleep Apnea in Postoperative Neurocognitive Disorders Among Older Noncardiac Surgery Patients: A Prospective Cohort Study

BACKGROUND

Obstructive sleep apnea is associated with increased dementia risk, yet its role in postoperative neurocognitive disorders is unclear. Here, we studied whether the severity of untreated obstructive sleep apnea is associated with the severity of postoperative neurocognitive disorder.

METHODS

In this single-center prospective cohort study, older noncardiac surgery patients aged 60 years and above underwent preoperative home sleep apnea testing, and pre- and postoperative delirium assessments and cognitive testing. Sleep apnea severity was determined using the measured respiratory event index (REI). Global cognitive change from before to 6 weeks (and 1 year) after surgery was used to measure postoperative neurocognitive disorder severity. Postoperative changes in individual cognitive domain performance along with subjective cognitive complaints and/or deficits in instrumental activities of daily living were used to measure postoperative neurocognitive disorder incidence.

RESULTS

Of 96 subjects who completed home sleep apnea testing, 58 tested positive for sleep apnea. In univariable analyses, sleep apnea severity was not associated with increased postoperative neurocognitive disorder severity at 6 weeks (global cognitive change ; [95% confidence interval [CI], -0.02 to 0.03]; P = .79) or 1-year after surgery (; [95% CI, -0.02 to 0.03]; P = .70). Adjusting for age, sex, baseline cognition, and surgery duration, sleep apnea severity remained not associated with increased postoperative neurocognitive disorder severity at 6 weeks (; [95% CI, -0.02 to 0.04]; P = .40) or 1-year after surgery (; [95% CI, -0.02 to 0.04]; P = .55). In a multivariable analysis, sleep apnea severity was not associated with postoperative neurocognitive disorder (either mild or major) incidence at 6 weeks (odds ratio [OR] = 0.89, [95% CI, 0.59-1.14]; P = .45) or 1-year postoperatively (OR = 1.01, [95% CI, 0.81-1.24]; P = .90). Sleep apnea severity was also not associated with postoperative delirium in univariable analyses (delirium incidence OR = 0.88, [95% CI, 0.59-1.10]; P = .37; delirium severity ; [95% CI, -0.02 to 0.03]; P = .79) or in multivariable analyses (delirium incidence OR = 1.07, [95% CI, 0.81-1.38]; P = .74; delirium severity OR = 0.95, [95% CI, 0.81-1.10]; P = .48).

CONCLUSIONS

In this older noncardiac surgery cohort, untreated sleep apnea was not associated with increased incidence or severity of postoperative neurocognitive disorder or delirium.

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.

Development and Validation of Machine Learning Models to Predict Postoperative Delirium Using Clinical Features and Polysomnography Variables

Background: Delirium affects up to 50% of patients following high-risk surgeries and is associated with poor long-term prognosis. This study employed machine learning to predict delirium using polysomnography (PSG) and sleep-disorder questionnaire data, and aimed to identify key sleep-related factors for improved interventions and patient outcomes. Methods: We studied 912 adults who underwent surgery under general anesthesia at a tertiary hospital (2013-2024) and had PSG within 5 years of surgery. Delirium was assessed via clinical diagnoses, antipsychotic prescriptions, and psychiatric consultations within 14 days postoperatively. Sleep-related data were collected using PSG and questionnaires. Machine learning predictions were performed to identify postoperative delirium, focusing on model accuracy and feature importance. Results: This study divided the 912 patients into an internal training set (700) and an external test set (212). Univariate analysis identified significant delirium risk factors: midazolam use, prolonged surgery duration, and hypoalbuminemia. Sleep-related variables such as fewer rapid eye movement (REM) episodes and higher daytime sleepiness were also linked to delirium. An extreme gradient-boosting-based classification task achieved an AUC of 0.81 with clinical variables, 0.60 with PSG data alone, and 0.84 with both, demonstrating the added value of PSG data. Analysis of Shapley additive explanations values highlighted important predictors: surgery duration, age, midazolam use, PSG-derived oxygen saturation nadir, periodic limb movement index, and REM episodes, demonstrating the relationship between sleep patterns and the risk of delirium. Conclusions: The artificial intelligence model integrates clinical and sleep variables and reliably identifies postoperative delirium, demonstrating that sleep-related factors contribute to its identification. Predicting patients at high risk of developing postoperative delirium and closely monitoring them could reduce the costs and complications associated with delirium.

Risk Factors for Acute Postsurgical Pain: A Narrative Review

Acute postsurgical pain (APSP) has received growing attention as a surgical outcome. When poorly controlled, APSP can affect short- and long-term outcomes in patients. Despite the steady increase in awareness about postoperative pain and standardization of pain prevention and treatment strategies, moderate-to-severe APSP is frequently reported in clinical practice. This is possibly because pain varies widely among individuals and is influenced by distinct factors, such as demographic, perioperative, psychological, and genetic factors. This review investigates the risk factors for APSP, including gender, age, obesity, smoking history, preoperative pain history, pain sensitivity, preoperative anxiety, depression, pain catastrophizing, expected postoperative pain, surgical fear, and genetic polymorphisms. By identifying patients having an increased risk of moderate-to-severe APSP at an early stage, clinicians can more effectively manage individualized analgesic treatment protocols with a combination of pharmacological and non-pharmacological interventions. This would alleviate the transition from APSP to chronic pain and reduce the severity of APSP-induced chronic physical disability and social psychological distress.

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.

Moderate-to-high risk of obstructive sleep apnea with excessive daytime sleepiness is associated with postoperative neurocognitive disorders: a prospective one-year follow-up cohort study

Background

Few studies found that obstructive sleep apnea (OSA) may be related to postoperative neurocognitive disorders (PND) including postoperative delirium (POD) and cognitive decline (POCD) in the early postoperative period. However, the results are controversial and need further verification, and no research has explored the effect of OSA on the incidence of PND during the 1-year follow-up periods. Furthermore, OSA patients with excessive daytime sleepiness (EDS) as a severe phenotype have more significant neurocognitive impairments, but the relationship between OSA with EDS and PND within 1 year after surgery has not been studied.

Objectives

To explore the effect of moderate-to-high risk of OSA and the moderate-to-high risk of OSA with EDS on PND within 1 year after surgery.

Methods

In this prospective cohort study, including 227 older patients, moderate-to-high risk of OSA (using STOP-BANG), subjective EDS (using Epworth Sleepiness Scale), and objective EDS (using Actigraphy) were selected as exposures. Key outcomes included POD during hospitalization (using Confusion Assessment Method-Severity), POCD at discharge, 1-month and 1-year after surgery (using Mini-Mental State Examination and Telephone Interview for Cognitive Status-40). We applied multiple logistic regression models to estimate the effect of moderate-to-high risk of OSA and moderate-to-high risk of OSA with EDS on PND.

Results

In the multivariate analysis, moderate-to-high risk of OSA was not associated with POD during hospitalization and POCD at discharge, 1-month, and 1-year after surgery (p > 0.05). However, the moderate-to-high risk of OSA with subjective EDS was related to POCD at discharge compared to the moderate-to-high risk of OSA or normal group (no moderate-to-high risk of OSA and no EDS) (p < 0.05). In addition, moderate-to-high risk of OSA with objective EDS was associated with POCD at discharge, 1-month, and 1-year postoperatively compared to the moderate-to-high risk of OSA or normal group (p < 0.05).

Conclusion

Moderate-to-high risk of OSA with EDS, not moderate-to-high risk of OSA alone, was a clinically helpful predictor for POCD within 1-year after surgery and should be routinely assessed before surgery.

The effectiveness of positive airway pressure therapy in reducing postoperative adverse outcomes in surgical patients with obstructive sleep apnea: A systematic review and meta-analysis

IMPORTANCE

Obstructive sleep apnea (OSA) is prevalent in surgical patients and is associated with an increased risk of adverse perioperative events.

STUDY OBJECTIVE

To determine the effectiveness of positive airway pressure (PAP) therapy in reducing the risk of postoperative complications in patients with OSA undergoing surgery.

DESIGN

Systematic review and meta-analysis searching Medline and other databases from inception to October 17, 2021. The search terms included: "positive airway pressure," "surgery," "post-operative," and "obstructive sleep apnea." The inclusion criteria were: 1) adult patients with OSA undergoing surgery; (2) patients using preoperative and/or postoperative PAP; (3) at least one postoperative outcome reported; (4) control group (patients with OSA undergoing surgery without preoperative and/or postoperative PAP therapy); and (5) English language articles.

PATIENTS

Twenty-seven studies included 30,514 OSA patients undergoing non-cardiac surgery and 837 OSA patients undergoing cardiac surgery.

INTERVENTION

PAP therapy MAIN RESULTS: In patients with OSA undergoing non-cardiac surgery, PAP therapy was associated with a decreased risk of postoperative respiratory complications (2.3% vs 3.6%; RR: 0.72, 95% CI: 0.51-1.00, asymptotic P = 0.05) and unplanned ICU admission (0.12% vs 4.1%; RR: 0.44, 95% CI: 0.19-0.99, asymptotic P = 0.05). No significant differences were found for all-cause complications (11.6% vs 14.4%; RR: 0.89, 95% CI: 0.74-1.06, P = 0.18), postoperative cardiac and neurological complications, in-hospital length of stay, and in-hospital mortality between the two groups. In patients with OSA undergoing cardiac surgery, PAP therapy was associated with decreased postoperative cardiac complications (33.7% vs 50%; RR: 0.63, 95% CI: 0.51-0.77, P < 0.0001), and postoperative atrial fibrillation (40.1% vs 66.7%; RR: 0.59, 95% CI 0.45-0.77, P < 0.0001).

CONCLUSION

In patients with OSA undergoing non-cardiac surgery, PAP therapy was associated with a 28% reduction in the risk of postoperative respiratory complications and 56% reduction in unplanned ICU admission. In patients with OSA undergoing cardiac surgery, PAP therapy decreased the risk of postoperative cardiac complications and atrial fibrillation by 37% and 41%, respectively.

The potential link between obstructive sleep apnea and postoperative neurocognitive disorders: current knowledge and possible mechanisms

PURPOSE

This narrative review examines the current evidence on whether obstructive sleep apnea (OSA) is associated with postoperative delirium (POD) and postoperative cognitive dysfunction (POCD). The mechanisms that could predispose OSA patients to these disorders are also explored.

SOURCE

Relevant literature was identified by searching for pertinent terms in Medline®, Pubmed, ScopusTM, and Google scholar databases. Case reports, abstracts, review articles, original research articles, and meta-analyses were reviewed. The bibliographies of retrieved sources were also searched to identify relevant papers.

PRINCIPAL FINDINGS

Seven studies have investigated the association between OSA and POD, with mixed results. No studies have examined the potential link between OSA and POCD. If these relationships exist, they could be mediated by several mechanisms, including increased neuroinflammation, blood-brain barrier breakdown, cerebrovascular disease, Alzheimer's disease neuropathology, disrupted cerebral autoregulation, sleep disruption, sympathovagal imbalance, and/or disrupted brain bioenergetics.

CONCLUSION

There is very limited evidence that OSA plays a role in postoperative neurocognitive disorders because few studies have been conducted in the perioperative setting. Additional perioperative prospective observational cohort studies and randomized controlled trials of sleep apnea treatment are needed. These investigations should also assess potential underlying mechanisms that could predispose patients with OSA to postoperative neurocognitive disorders. This review highlights the need for more research to improve postoperative neurocognitive outcomes for patients with OSA.

Postoperative pain management in non-traumatic emergency general surgery: WSES-GAIS-SIAARTI-AAST guidelines

BACKGROUND

Non-traumatic emergency general surgery involves a heterogeneous population that may present with several underlying diseases. Timeous emergency surgical treatment should be supplemented with high-quality perioperative care, ideally performed by multidisciplinary teams trained to identify and handle complex postoperative courses. Uncontrolled or poorly controlled acute postoperative pain may result in significant complications. While pain management after elective surgery has been standardized in perioperative pathways, the traditional perioperative treatment of patients undergoing emergency surgery is often a haphazard practice. The present recommended pain management guidelines are for pain management after non-traumatic emergency surgical intervention. It is meant to provide clinicians a list of indications to prescribe the optimal analgesics even in the absence of a multidisciplinary pain team.

MATERIAL AND METHODS

An international expert panel discussed the different issues in subsequent rounds. Four international recognized scientific societies: World Society of Emergency Surgery (WSES), Global Alliance for Infection in Surgery (GAIS), Italian Society of Anesthesia, Analgesia Intensive Care (SIAARTI), and American Association for the Surgery of Trauma (AAST), endorsed the project and approved the final manuscript.

CONCLUSION

Dealing with acute postoperative pain in the emergency abdominal surgery setting is complex, requires special attention, and should be multidisciplinary. Several tools are available, and their combination is mandatory whenever is possible. Analgesic approach to the various situations and conditions should be patient based and tailored according to procedure, pathology, age, response, and available expertise. A better understanding of the patho-mechanisms of postoperative pain for short- and long-term outcomes is necessary to improve prophylactic and treatment strategies.

The prevention of delirium in elderly surgical patients with obstructive sleep apnea (PODESA): a randomized controlled trial

BACKGROUND

Obstructive sleep apnea (OSA) is associated with neurocognitive impairment - a known risk factor for postoperative delirium. However, it is unclear whether OSA increases the risk of postoperative delirium and whether treatment is protective. The objectives of this study were to identify OSA with a home sleep apnea test (HSAT) and to determine whether auto-titrating positive airway pressure (APAP) reduces postoperative delirium in older adults with newly diagnosed OSA undergoing elective hip or knee arthroplasty.

METHODS

We conducted a multi-centre, randomized controlled trial at three academic hospitals in Canada. Research ethics board approval was obtained from the participating sites and informed consent was obtained from participants. Inclusion criteria were patients who were [Formula: see text]0 years and scheduled for elective hip or knee replacement. Patients with a STOP-Bang score of ≥ 3 had a HSAT. Patients were defined as having OSA if the apnea-hypopnea index was ≥ 10/h. These patients were randomized 1:1 to either: 1) APAP for 72 h postoperatively or until discharge, or 2) routine care after surgery. The primary outcome was postoperative delirium, assessed twice daily with the Confusion Assessment Method for 72 h or until discharge or by chart review. The secondary outcome measures included length of stay, and perioperative complications occurring within 30 days after surgery.

RESULTS

Of 549 recruited patients, 474 completed a HSAT. A total of 234 patients with newly diagnosed OSA were randomized. The mean age was 68.2 (6.2) years and 58.6% were male. Analysis was performed on 220 patients. In total, 2.7% (6/220) patients developed delirium after surgery: 4.4% (5/114) patients in the routine care group, and 0.9% (1/106) patients in the treatment group (P = 0.21). The mean length of stay for the APAP vs. the routine care group was 2.9 (2.9) days vs. 3.5 (4.5) days (P = 0.24). On postoperative night 1, 53.5% of patients used APAP for 4 h/night or more, this decreased to 43.5% on night 2, and 24.6% on night 3. There was no difference in intraoperative and postoperative complications between the two groups.

CONCLUSIONS

We had an unexpectedly low rate of postoperative delirium thus we were unable to determine if postoperative delirium was reduced in older adults with newly diagnosed OSA receiving APAP vs. those who did not receive APAP after elective knee or hip arthroplasty.

TRIAL REGISTRATION

This trial was retrospectively registered in clinicaltrials.gov NCT02954224 on 03/11/2016.

Association between sleep quality and general anesthesia in teenager under elective surgery: a prospective study

OBJECTIVE

Anesthesia was reported to be associated with lowered postoperative sleep quality in adults, but its effect on teenager was less understood. This study was conducted to explore the association between postoperative sleep quality and general anesthesia in teenagers.

METHODS

A prospective study was conducted. Teenagers aged from 12 to 16 years who were treated with general anesthesia and under urologic or otolaryngologic surgery were recruited. Healthy teenagers matched by sex and age (± 3 years) with the specific case were recruited as the controls. The Sleep Habits Questionnaire was applied to assess the sleep quality of the teenagers. We applied a logistic regression analysis to evaluate the association between general anesthesia in teenagers under elective surgery and poor sleep quality. Risk ratio (RR) and its corresponding 95% confidence interval (CI) were computed.

RESULTS

A total of 212 teenagers were included comprising 106 patients with general anesthesia who underwent urologic or otolaryngologic surgery and 106 healthy controls. The male participants were accounting for 47.2% (100/212). Anesthesia duration and surgery duration in the patients were 103.7 ± 14.4 min and 162.1 ± 17.0 min, respectively. Positive associations between general anesthesia and poor sleep quality in the 1st, 3rd, and 7th postoperative days were found, and RRs and their corresponding 95%CIs were 4.87 (1.72-13.79), 3.33 (1.22-9.1), and 3.26 (1.07-9.93), respectively. However, there was a lack of statistical associations before surgery and after 14 postoperative days.

CONCLUSIONS

Teenagers who were treated with general anesthesia and under urologic or otolaryngologic surgery might have poor sleep quality within 7 postoperative days.

The Role of Perioperative Sleep Disturbance in Postoperative Neurocognitive Disorders

Postoperative neurocognitive disorder (PND) increases the length of hospital stay, mortality, and risk of long-term cognitive impairment. Perioperative sleep disturbance is prevalent and commonly ignored and may increase the risk of PND. However, the role of perioperative sleep disturbances in PND remains unclear. Nocturnal sleep plays an indispensable role in learning, memory, and maintenance of cerebral microenvironmental homeostasis. Hospitalized sleep disturbances also increase the incidence of postoperative delirium and cognitive dysfunction. This review summarizes the role of perioperative sleep disturbances in PND and elucidates the potential mechanisms underlying sleep-deprivation-mediated PND. Activated neuroinflammation and oxidative stress; impaired function of the blood-brain barrier and glymphatic pathway; decreased hippocampal brain-derived neurotrophic factor, adult neurogenesis, and sirtuin1 expression; and accumulated amyloid-beta proteins are associated with PND in individuals with perioperative sleep disorders. These findings suggest that the improvement of perioperative sleep might reduce the incidence of postoperative delirium and postoperative cognitive dysfunction. Future studies should further investigate the role of perioperative sleep disturbance in PND.

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.