Effect of Sleep Disorder on Delirium in Post-Cardiac Surgery Patients

Risk factors of delirium after cardiac surgery: a systematic review and meta-analysis

BACKGROUND

Post-operative delirium (POD) is a relatively common occurrence following surgical procedures, particularly cardiac surgeries. Given that the majority of pharmacologic treatments for delirium have demonstrated inadequate efficacy, it is of great importance to identify risk factors to prevent delirium or reduce its complications. Consequently, in this systematic review and meta-analysis, we identified risk factors of POD after cardiac surgery.

METHOD

A comprehensive search of the literature was conducted using the databases Scopus, PubMed, and Web of Science from the inception to April 22, 2024. The objective was to identify prospective cohorts that had assessed the risk factors associated with POD in patients undergoing cardiac surgery using multivariate regression.

RESULTS

Of the 3,166 studies that were initially screened, 23 were included in the review. Nine risk factors were evaluated including age (OR 1.06, 95% CI (1.04, 1.08), p < 0.001), pre-operative depression (OR 3.71, 95% CI (2.45, 5.62), p < 0.001), post-operative atrial fibrillation (AF) (OR 2.39, 95% CI (1.79, 3.21), p < 0.001), hypertension (HTN) (OR 1.64, 95% CI (0.75, 3.56), p = 0.212), age ≥ 65 (OR 3.32, 95% CI (2.40, 4.60), p < 0.001), pre-operative AF (OR 4.43, 95% CI (2.56, 7.69), p < 0.001), diabetes mellitus (OR 2.16, 95% CI (1.39, 3.35), p = 0.001), combined coronary artery bypass graft (CABG) + valve surgery (OR 2.73, 95% CI (1.66, 4.49), p < 0.001), and cardiopulmonary bypass (CPB) time (OR 1.02, 95% CI (1.01, 1.04), p = 0.001).

CONCLUSIONS

A total of nine risk factors were evaluated, from which eight were found to have a statistically significant effect on the risk of developing POD. These factors can be employed to more effectively identify at-risk patients and to prevent the occurrence of POD. Furthermore, this approach can facilitate earlier diagnosis and more effective patient care.

The utility of the Montreal cognitive assessment (MoCA) in detecting cognitive impairment in surgical populations - A systematic review and meta-analysis

STUDY OBJECTIVE

To determine the diagnostic accuracy of the Montreal Cognitive Assessment (MoCA) in detecting cognitive impairment (CI) and assess the association of MoCA scores with adverse postoperative outcomes in surgical populations.

DESIGN

Systematic review and meta-analysis.

SETTING

Perioperative setting.

PATIENTS

Adults undergoing elective or emergent surgery screened for CI preoperatively using the MoCA.

MEASUREMENTS

The outcomes included the diagnostic accuracy of the MoCA in screening for CI and the pooled prevalence of CI in various surgical populations. CI and its association with adverse events including delirium, hospital length-of-stay (LOS), postoperative complications, discharge destination, and mortality was determined.

MAIN RESULTS

Twenty-six studies (5059 patients, 18 non-cardiac studies, 8 cardiac studies) were included. With a MoCA cut-off score of <26, the prevalence of preoperative CI was 48% (95% CI: 41%-54%). The MoCA had 0.87 (95% CI: 0.79-0.93) sensitivity, 0.72 (95% CI: 0.62-0.80) specificity, PPV of 0.74 (95% CI: 0.65-0.81), and NPV of 0.86 (95% CI: 0.77-0.92) when validated against Petersen criteria, the Diagnostic and Statistical Manual of Mental Disorders, or the National Institute on Aging and the Alzheimer's Association criteria to identify CI. Using the MoCA as a screening tool, the LOS was 3.75 (95% CI: -0.03-7.53, P = 0.05, not significant) days longer in the CI group after non-cardiac surgeries and 3.33 (95% CI: 1.24-5.41, P < 0.002) days longer after cardiac surgeries than the non-cognitively impaired group.

CONCLUSIONS

MoCA had been validated in the surgical population. MoCA with a cut-off score of <26 was shown to have 87% sensitivity and 72% specificity in identifying CI. A positive screen in MoCA was associated with a 3-day longer hospital LOS in cardiac surgery in the CI group than in the non-CI group.

A Mendelian randomization-based study of the causal relationship between leisure sedentary behavior and delirium

BACKGROUND

Delirium is an acute or subacute change in mental status caused by various factors. We evaluated the causal relationship between leisure sedentary behaviors (LSBs) and delirium.

METHODS

A two-sample Mendelian randomization (MR) study was performed to evaluate the causal relationship between sedentary behaviors (time spent watching television, time spent using computer, and time spent driving) and delirium. Statistical information for the associations between single nucleotide polymorphisms (SNPs) and the traits of interest was obtained from independent consortia that focused on European populations. The dataset for LSBs was acquired from genome-wide association studies (GWAS) comprising a substantial sample size: 437887 samples for time spent watching television, 360,895 for time spent using computer, and 310,555 for time spent driving. A GWAS with 1269 delirium cases and 209,487 controls was used to identify genetic variation underlying the time of LSBs. We used five complementary MR methods, including inverse variance weighted method (IVW), MR-Egger, weighted median, weighted mode, and simple mode.

RESULTS

Genetically predicted time spent watching television (odds ratio [OR]: 2.921, 95 % confidence interval [CI]: 1.381-6.179) demonstrated significant association with delirium (P = 0.005), whereas no significant associations were observed between time spent using computer (OR: 0.556, 95 % CI: 0.246-1.257, P = 0.158) and time spent driving (OR: 1.747, 95 % CI: 0.09-3. 40, P = 0.713) and delirium. Sensitivity analyses supported a causal interpretation, with limited evidence of significant bias from genetic pleiotropy. Moreover, our MR assumptions appeared to be upheld, enhancing the credibility of our conclusions.

LIMITATIONS

Larger sample sizes are needed to validate the findings of our study.

CONCLUSION

Time spent watching television is a significant risk factor for delirium. Reducing television time may be an important intervention for those at higher risk of delirium.

Association Between Preoperative Long-Term Poor Sleep Quality and Postoperative Delirium in Elderly Patients Undergoing Cardiac Surgery: A Multi-Center Observational Study

BACKGROUND

Delirium is a common complication in elderly patients after cardiac surgery, and sleep disorders have been suggested as a potential risk factor. However, few studies have explored the link between long-term preoperative poor sleep quality and postoperative delirium (POD) in this population. This study aimed to investigate the association between preoperative sleep quality and POD in elderly cardiac surgery patients.

METHODS

The study enrolled 194 patients aged 60 years or older who underwent cardiac surgery. The Pittsburgh Sleep Quality Index (PSQI) objectively assessed preoperative sleep quality, while the Confusion Assessment Method screened for POD. The measurable outcomes encompassed the identification of risk factors associated with POD, while the secondary outcomes focused on factors influencing levels of consciousness. The statistical analysis is logistic regression analysis.

RESULTS

Patients with POD had a higher prevalence of preoperative sleep disorders and higher PSQI scores than those without delirium (12.9 ± 5.1 vs 7.8 ± 3.4, P = .007). Logistic regression analysis demonstrated that the number of months with high PSQI scores and age were significantly associated with POD. The predictive ability of the number of months with high PSQI scores for POD was .762 (95% CI: .671-.854). Multivariate linear regression analysis revealed that preoperative sleep disorder was a significant predictor of exacerbation of POD (P < .05).

CONCLUSION

This study suggests that long-term poor preoperative sleep quality, as assessed by the PSQI, is associated with an increased risk of POD in elderly patients undergoing cardiac surgery.

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).

Effects of Chinese traditional five-element music intervention on postoperative delirium and sleep quality in elderly patients after non-cardiac surgery: a randomized controlled trial

BACKGROUND

Postoperative delirium (POD) is a common neurologic disorder among elderly patients after non-cardiac surgery, which leads to various negative outcomes. Sleep disorder is considered an important cause of POD. The objective of this study was to investigate whether the Chinese traditional five-element music intervention could reduce POD by improving sleep quality in elderly patients undergoing non-cardiac surgery.

METHODS

A total of 132 patients aged 65 to 90 years who underwent non-cardiac surgery were randomized to two groups: the intervention (n = 60) and the control group (n = 63). Patients in the intervention group were subjected to the Chinese traditional five-element music intervention during the perioperative, while patients in the control group had no music intervention. POD was evaluated using the Confusion Assessment Method (CAM) in the first 5 days after surgery. The Richards‒Campbell Sleep Questionnaire (RCSQ) was used to assess subjective sleep quality. The levels of nocturnal melatonin and cortisol in saliva were measured on the preoperative and the first 2 postoperative days.

RESULTS

The incidence of POD within 5 days was 27.0% in the control group and 11.7% in the intervention group. Preoperative PSQI and MMSE scores were associated with POD. The RCSQ scores on the first postoperative day were significantly decreased in the two groups compared to the preoperative day. Compared to the control group, the RCSQ scores showed a significant improvement in the intervention group on the first postoperative day. Compared to the control group, the level of saliva melatonin in the intervention group showed a significant increase on the first postoperative day. However, there was no statistical difference in cortisol levels between the two groups.

CONCLUSIONS

Chinese traditional five-element music intervention decreased the incidence of POD in elderly patients who underwent noncardiac surgery via improving sleep quality, which may be associated with increased levels of melatonin.

Integrative proteomics and metabolomics data analysis exploring the mechanism of brain injury after cardiac surgery in chronic stress rats

OBJECTIVE

Preoperative chronic stress (CS) is associated with postoperative brain injury in patients undergoing open heart cardiac surgery. This research is to explore the potential molecular biological mechanisms of brain damage following cardiac surgery in preoperative CS rats by the analyses combining proteomics and metabolomics.

METHODS

We constructed the chronic unpredictable stress (CUS) and cardiac surgery models in adult rats. We proved the brain injury in CUS cardiac surgery rats by Hematoxylin-Eosin (H&E) staining, followed by separating the hippocampal tissue and investigating the potential mechanisms of brain injury by the methods of data-independent acquisition proteomics and untargeted metabolomics.

RESULTS

The signaling pathways of glycoproteins and metabolism of amino acids were the main possible mechanisms of brain injury in CUS rats following cardiac surgery according to the proteomics and metabolomics. In addition, the pathways of animo acids metabolism such as the pathways of lysine degradation and β-alanine metabolism may be the main mechanism of cardiac surgery related brain injury in preoperative CUS rats.

CONCLUSIONS

The pathways of animo acids metabolism such as lysine degradation and β-alanine metabolism may be the potential mechanisms of brain injury in CUS rats following cardiac surgery. We should focus on the varieties of bioproteins and metabolites in these pathways, and related changes in other signaling pathways induced by the two pathways.

Effects of short-term preoperative intranasal dexmedetomidine plus conventional treatment on delirium following cardiac surgery in patients with sleep disorders

STUDY OBJECTIVES

To assess whether preoperative dexmedetomidine (DEX) nasal drips combined with conventional treatment could mitigate the occurrence of postoperative delirium (POD).

DESIGN

A prospective randomised controlled study.

SETTING

The cardiac surgery intensive care unit (CSICU) and patient hospitalisation ward at a university hospital.

PARTICIPANTS

A total of 100 patients (aged ≥60 years) undergoing cardiac surgery at a university hospital between 7 January 2022, and 30 November 2022 met the eligibility criteria and were included in the study.

INTERVENTIONS

Patients with sleep disorders (Pittsburgh Sleep Quality Index ≥8) were divided into two groups: Group A (the placebo group, n=50), receiving a short-term preoperative placebo combined with conventional treatment and Group B (the DEX group, n=50), receiving short-term preoperative DEX combined with conventional treatment.

MEASUREMENTS AND RESULTS

The Confusion Assessment Method for the ICU (CAM-ICU) was used for POD assessment in the CSICU, while the CAM was employed to assess delirium in the patient ward. Group B demonstrated a reduced incidence of POD compared to Group A (12% vs. 30%, odds ratio: 0.318, 95% confidence interval: 0.112-0.905, p=0.027).

CONCLUSION

The combined treatment involving DEX demonstrated a decreased incidence of POD in elderly individuals with sleep disorders undergoing cardiac surgery compared to the placebo combination treatment.

TRIAL REGISTRATION

URL: www.chictr.org.cn with registration number ChiCTR 2100043968, registered on 06/03/2021.

Prevention of post-operative delirium using an overnight infusion of dexmedetomidine in patients undergoing cardiac surgery: a pragmatic, randomized, double-blind, placebo-controlled trial

BACKGROUND

After cardiac surgery, post-operative delirium (PoD) is acknowledged to have a significant negative impact on patient outcome. To date, there is no valuable and specific treatment for PoD. Critically ill patients often suffer from poor sleep condition. There is an association between delirium and sleep quality after cardiac surgery. This study aimed to establish whether promoting sleep using an overnight infusion of dexmedetomidine reduces the incidence of delirium after cardiac surgery.

METHODS

Randomized, pragmatic, multicentre, double-blind, placebo controlled trial from January 2019 to July 2021. All adult patients aged 65 years or older requiring elective cardiac surgery were randomly assigned 1:1 either to the dexmedetomidine group or the placebo group on the day of surgery. Dexmedetomidine or matched placebo infusion was started the night after surgery from 8 pm to 8 am and administered every night while the patient remained in ICU, or for a maximum of 7 days. Primary outcome was the occurrence of postoperative delirium (PoD) within the 7 days after surgery.

RESULTS

A total of 348 patients provided informed consent, of whom 333 were randomized: 331 patients underwent surgery and were analysed (165 assigned to dexmedetomidine and 166 assigned to placebo). The incidence of PoD was not significantly different between the two groups (12.6% vs. 12.4%, p = 0.97). Patients treated with dexmedetomidine had significantly more hypotensive events (7.3% vs 0.6%; p < 0.01). At 3 months, functional outcomes (Short-form 36, Cognitive failure questionnaire, PCL-5) were comparable between the two groups.

CONCLUSION

In patients recovering from an elective cardiac surgery, an overnight infusion of dexmedetomidine did not decrease postoperative delirium. Trial registration This trial was registered on ClinicalTrials.gov (number: NCT03477344; date: 26th March 2018).

The efficacy of earplugs and eye masks for delirium severity and sleep quality in patients undergoing coronary artery bypass grafting in cardiac intensive care units: A single-blind, randomised controlled trial

BACKGROUND AND PURPOSE

Delirium is a neuropsychiatric syndrome with a wide range of possible causes and multiple complications in patients admitted to intensive care units. It is, therefore, necessary to seek appropriate and safe strategies to prevent and manage delirium. This study is intended to examine the efficacy of eye masks and earplugs for delirium severity and sleep quality in patients with coronary artery bypass grafting in a cardiac intensive care unit.

MATERIALS AND METHODS

This single-blind, randomised controlled trial was conducted on 114 patients who were consecutively enrolled and randomly assigned to either the experimental group or the control group. The experimental group received routine care plus eye masks and earplugs, and the control group received only routine care. The delirium severity and sleep quality were measured with the Neelon and Champagne confusion scale and the Verran and Snyder-Halpern sleep scale.

RESULTS

The mean delirium severity score differed significantly between the two groups on the second, third, and fourth postoperative days (p < 0.001). Although the trend of changes in the mean delirium severity score from the first postoperative day (before the intervention) to the second, third, and fourth postoperative days was downward in the two groups (trending towards higher delirium severity), the control group experienced greater changes than the experimental group. An intragroup analysis of delirium severity detected a statistically significant difference in both the experimental and control groups (p < 0.001). The sleep quality domains (sleep disturbance, sleep effectiveness, sleep supplementation) showed a statistically significant difference between the two groups across the three intervention days (p < 0.001).

CONCLUSION

The overnight use of eye masks and earplugs were found to have positive effects on sleep quality domains (sleep disturbance, sleep effectiveness, sleep supplementation) and delirium severity in coronary artery bypass grafting patients admitted to the cardiac intensive care unit for several days. It was also found that a significant interaction effect between the sleep disturbance subscale and delirium severity exists.

CLINICAL TRIAL REGISTRATION NUMBER

(https://en.irct.ir): IRCT20210523051370N2.

Impact of Preoperative Sleep Disturbances on Postoperative Delirium in Patients with Intracranial Tumors: A Prospective, Observational, Cohort Study

Background

Postoperative delirium (POD) is prevalent in craniotomy patients and is associated with high mortality. Sleep disturbances are receiving increasing attention from clinicians as associated risk factors for postoperative complications. This study aimed to determine the impact of preoperative sleep disturbances on POD in craniotomy patients.

Methods

We recruited 130 patients undergoing elective craniotomy for intracranial tumors between May 1st and December 30th, 2022. Preoperative subjective sleep disturbances were assessed using the Pittsburgh Sleep Quality Index on the day of admission. We also measured objective perioperative sleep patterns using a dedicated sleep monitoring device 3 days before and 3 days after the surgery. POD was assessed twice daily using the Confusion Assessment Model for the Intensive Care Unit within the first week after craniotomy.

Results

Preoperative sleep disturbances were diagnosed in 49% of the study patients, and POD was diagnosed in 22% of all the study patients. Sleep disturbances were an independent risk factor for POD (OR: 2.709, 95% CI: 1.020-7.192, P = 0.045). Other risk factors for POD were age (OR: 3.038, 95% CI: 1.195-7.719, P = 0.020) and the duration of urinary catheterization (OR: 1.246, 95% CI: 1.025-1.513, P = 0.027). Perioperative sleep patterns (including sleep latency, deep sleep duration, frequency of awakenings, apnea-hypopnea index, and sleep efficiency) were significantly associated with POD.

Conclusion

This study demonstrated that preoperative sleep disturbances predispose patients undergoing craniotomy to POD, also inferred a correlation between perioperative sleep patterns and POD. The targeted screening and intervention specifically for sleep disturbances during the perioperative period are immensely required.

Effect of pharmacist-led intervention protocol on preventing postoperative delirium after elective cardiovascular surgery

Postoperative delirium (PD) is an acute brain dysfunction, with a particularly high incidence after cardiovascular surgery. Pharmacist-led interventions show limited evidence in attenuating PD in cardiovascular surgery. In this retrospective cohort study, we aimed to clarify the risk factors of PD for cardiovascular surgery focused on pharmacotherapy and elucidate the effect of pharmacist-led intervention on the PD attenuation rate based on protocol-based pharmaceutical management (PBPM). This study included 142 adult patients who underwent elective valve replacement or valvuloplasty. The risk factors for PD were investigated using multivariate logistic regression analysis. Taking risk factors into consideration, a protocol was developed to discontinue benzodiazepines prescriptions by ward pharmacists, and replace with ramelteon and suvorexant if all the following factors apply: 1) number of medications ≥ 6 drugs, 2) number of doses to take ≥ 4 times, and 3) regular use of benzodiazepines or insomnia. Subsequently, the PD rate was compared during a period of two years and 6 months between the pre-PBPM (n = 39) and post-PBPM (n = 62). The PD rate for elective valve replacement or valvuloplasty was 25% (35/142). The adjusted odds ratio for polypharmacy was 3.3 (95% confidence interval: 1.2-8.9, p = 0.016), suggesting that preoperative risk assessment may be essential for patients with polypharmacy. The PD rate significantly decreased to 13% (8/62) in the post-PBPM group compared with 33% (13/39) in the pre-PBPM group (p = 0.014). There was a significant decrease in benzodiazepines use in post-PBPM compared with pre-PBPM (p = 0.026); however, the rate of ramelteon and orexin receptor antagonists use increased by PBPM introduction (p < 0.001). Although the present PBPM still requires further modification, it is simple and potentially useful for pharmacists to assess the risk of patients undergoing any elective cardiovascular surgery.

Does improving sleep for the critically ill reduce the incidence and duration of delirium? An evidence-based review

Delirium is associated with poor patient outcome. Critical-care nurses maintain that patients with disrupted sleep appear to develop delirium. We sought to explore whether improving sleep in the critically ill patients reduced the incidence and duration of delirium. Our review of five relevant studies suggests that there is low-quality evidence that improving sleep may reduce the incidence of delirium. The bidirectional association between delirium and sleep stymies research in this area, and thus, establishing cause and effect, is difficult. Research exploring other patient-centred outcomes, such as pain intensity, suggests that enhancing sleep may improve these outcomes.

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.

Perioperative Sleep Disorder: A Review

Patients in the perioperative period usually present with different types and degrees of sleep disorders, which can severely affect their post-operative outcomes. Multiple risk factors may lead to the occurrence of perioperative sleep disorders, including personal factors, psychological factors, surgery factors, and environmental factors. In this review, we summarize the potential risk factors for perioperative sleep disorders during hospitalization. And it also provides an overview of perioperative outcomes and potential therapeutic prevention of perioperative sleep disorders. However, the further search is necessary to investigate the effectiveness and safety of preventions in the clinical practice and push forward the therapies.

Risk of Postoperative Hyperalgesia in Adult Patients with Preoperative Poor Sleep Quality Undergoing Open-heart Valve Surgery

Purpose

Studies have reported that preoperative poor sleep quality could decrease the pain threshold in patients undergoing noncardiac surgery. However, the risk of postoperative hyperalgesia (HA) in cardiac surgery patients with preoperative poor sleep quality remains unclear.

Patients and Methods

We retrospectively collected clinical data from patients undergoing open-heart valve surgery between May 1 and October 31, 2019, in Fuwai Hospital (Beijing). We assessed preoperative sleep quality and postoperative pain severity using the Pittsburgh sleep quality index (PSQI) and numerical pain rating scale (NPRS), respectively. A PSQI of six or greater was considered to indicate poor sleep quality, and a NPRS of four or greater was considered to indicate HA. Multivariable logistic regression analysis was used to study the risk of postoperative HA in patients with preoperative poor sleep quality.

Results

We divided 214 eligible patients into two groups based on postoperative HA; HA group: n=61 (28.5%) and nonHA group: n=153 (71.5%). Compared with nonHA patients, patients with postoperative HA showed a higher percentage of history of smoking, 17 (11.1%) vs 15 (24.6%) and alcohol abuse, 5 (3.3%) vs 6 (9.8%), higher intraoperative dose of sufentanil (median, 1.02 vs 1.12 μg/kg/h), and longer duration of ventilation with tracheal catheter (median, 760 vs 934 min). Preoperative poor sleep quality was associated independently with an increased risk of postoperative HA (adjusted odds ratio [AOR]: 2.66; 95%CI: 1.31–5.39, P=0.007). Stratification by history of smoking revealed a stronger risk of postoperative HA in nonsmoking patients with preoperative poor sleep quality (AOR: 3.40; 95%CI: 1.51–7.66, P=0.003). No risk was found in patients who had history of smoking (AOR: 0.83; 95%CI: 0.14–4.75, P=0.832).

Conclusion

Preoperative poor sleep quality is an independent risk factor for postoperative HA in adult patients undergoing open-heart valve surgery who had no history of smoking.

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.