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

The influence of sleep disorders on perioperative neurocognitive disorders among the elderly: A narrative review

This review comprehensively assesses the epidemiology, interaction, and impact on patient outcomes of perioperative sleep disorders (SD) and perioperative neurocognitive disorders (PND) in the elderly. The incidence of SD and PND during the perioperative period in older adults is alarmingly high, with SD significantly contributing to the occurrence of postoperative delirium. However, the clinical evidence linking SD to PND remains insufficient, despite substantial preclinical data. Therefore, this study focuses on the underlying mechanisms between SD and PND, underscoring that potential mechanisms driving SD-induced PND include uncontrolled central nervous inflammation, blood-brain barrier disruption, circadian rhythm disturbances, glial cell dysfunction, neuronal and synaptic abnormalities, impaired central metabolic waste clearance, gut microbiome dysbiosis, hippocampal oxidative stress, and altered brain network connectivity. Additionally, the review also evaluates the effectiveness of various sleep interventions, both pharmacological and nonpharmacological, in mitigating PND. Strategies such as earplugs, eye masks, restoring circadian rhythms, physical exercise, noninvasive brain stimulation, dexmedetomidine, and melatonin receptor agonists have shown efficacy in reducing PND incidence. The impact of other sleep-improvement drugs (e.g., orexin receptor antagonists) and methods (e.g., cognitive-behavioral therapy for insomnia) on PND is still unclear. However, certain drugs used for treating SD (e.g., antidepressants and first-generation antihistamines) may potentially aggravate PND. By providing valuable insights and references, this review aimed to enhance the understanding and management of PND in older adults based on SD.

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.

Geriatric Assessment in Colorectal Surgery: A Systematic Review

INTRODUCTION

The prevalence of colorectal surgery among older adults is expected to rise due to the aging population. Geriatric conditions (e.g., frailty) are risk factors for poor surgical outcomes. The goal of this systematic review is to examine how current literature describes geriatric assessment interventions in colorectal surgery and associated outcomes.

METHODS

Systematic searches of Ovid MEDLINE, Cochrane Library, CINAHL, Embase, and Web of Science were completed. Review was performed according to Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines and prospectively registered in PROSPERO, the international prospective register of systematic reviews in health and social care. All cohort studies and randomized trials of adult colorectal surgery patients where geriatric assessment was performed were included. Geriatric assessment with/without management interventions were identified and described.

RESULTS

Seven-hundred ninety-three studies were identified. Duplicates (197) were removed. An additional 525 were excluded after title/abstract review. After full-text review, 20 studies met the criteria. Reference list review increased final total to 25 studies. All 25 studies were cohort studies. No randomized clinical trials were identified. Heterogeneous assessments were organized into geriatrics domains (mind, mobility, medications, matters most, and multi-complexity). Incomplete evaluations across geriatric domains were performed with few studies describing the use of assessments to impact management decisions.

CONCLUSIONS

There are no randomized trials assessing the impact of geriatric assessment to tailor management strategies and improve outcomes in colorectal surgery. Few studies performed assessments to evaluate the geriatric domain matters most. These findings represent a gap in evidence for the efficacy of geriatric assessment and management strategies in colorectal surgical care.

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

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

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

Background

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

Methods

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

Results

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

Conclusion

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

The Impact of Regional Nerve Blocks on Postoperative Delirium or Cognitive Dysfunction following Thoracic Surgery: A Systematic Review and Meta-Analysis

Regional nerve blocks (NBs) mitigate the occurrence of postoperative cognitive dysfunction (POCD) and postoperative delirium (POD) in adult patients undergoing thoracic surgery. This study aimed to determine the exact effect of NBs on POCD and POD. Electronic databases, including PubMed, EMBASE, CINAHL, Scopus, and Web of Science, were searched for studies. The primary outcome was the incidence of POD or POCD. The secondary outcome was pain scores assessed 24 and 48 h postoperatively. We calculated the log odds ratio (LOR) and standardized mean difference (SMD) with 95% confidence intervals (CIs). The LOR was converted to an odds ratio (OR). In the analysis of 1010 patients from seven randomized controlled trials, POD and POCD rates were 14.1% and 16.7%, respectively, in the NB group, and higher, at 27.3% and 35.2%, in the control group. NBs reduced the incidence of POD (OR, 0.44; 95%CI 0.30 to 0.64; p < 0.001; I2 = 0.00%) and POCD (OR, 0.43; 95%CI 0.24 to 0.76; p < 0.001; I2 = 0.00%). NBs reduced pain scores at 24 h (SMD, -2.60; 95%CI -3.90 to -1.30, p < 0.001; I2 = 97.68%) and 48 h (SMD, -1.80; 95%CI -3.18 to -0.41, p = 0.01; I2 = 98.14%) postoperatively. NBs mitigated the occurrence of POD and POCD in adult patients after thoracic surgery.

Delirium and sleep disturbances-A narrative review

BACKGROUND

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

OBJECTIVE

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSION

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Sleep Loss the night before surgery and incidence of postoperative delirium in adults 65-95 years of age

STUDY OBJECTIVES

To describe the association between preoperative sleep disruption and postoperative delirium.

METHODS

Prospective cohort study with six time points (3 nights pre-hospitalization and 3 nights post-surgery). The sample included 180 English-speaking patients ≥65 years old scheduled for major non-cardiac surgery and anticipated minimum hospital stay of 3 days. Six days of wrist actigraphy recorded continuous movement to estimate wake and sleep minutes during the night from 22:00 to 05:59. Postoperative delirium was measured by a structured interview using the Confusion Assessment Method. Sleep variables for patients with (n = 32) and without (n = 148) postoperative delirium were compared using multivariate logistic regression.

RESULTS

Participants had a mean age of 72 ± 5 years (range 65-95 years). The incidence of postoperative delirium during any of the three postoperative days was 17.8%. Postoperative delirium was significantly associated with surgery duration (OR = 1.49, 95% CI 1.24-1.83) and sleep loss >15% on the night before surgery (OR = 2.64, 95% CI 1.10-6.62). Preoperative symptoms of pain, anxiety and depression were unrelated to preoperative sleep loss.

CONCLUSIONS

In this study of adults ≥65 years of age, short sleep duration was more severe preoperatively in the patients who experienced postoperative delirium as evidenced by sleep loss >15% of their normal night's sleep. However, we were unable to identify potential reasons for this sleep loss. Further investigation should include additional factors that may be associated with preoperative sleep loss to inform potential intervention strategies to mitigate preoperative sleep loss and reduce risk of postoperative delirium.

A randomised controlled trial of dexmedetomidine for delirium in adults undergoing heart valve surgery

Dexmedetomidine might reduce delirium after cardiac surgery. We allocated 326 participants to an infusion of dexmedetomidine at a rate of 0.6 μg kg^-1 for 10 min and then at 0.4 μg.kg^-1 .h^-1 until the end of surgery; 326 control participants received comparable volumes of saline. We detected delirium in 98/652 (15%) participants during the first seven postoperative days: 47/326 after dexmedetomidine vs. 51/326 after placebo, p = 0.62, adjusted relative risk (95%CI) 0.86 (0.56-1.33), p = 0.51. Postoperative renal impairment (Kidney Disease Improving Global Outcomes stages 1, 2 and 3) was detected in 46, 9 and 2 participants after dexmedetomidine and 25, 7 and 4 control participants, p = 0.040. Intra-operative dexmedetomidine infusion did not reduce the incidence of delirium after cardiac valve surgery but might impair renal function.

Effect of mini-dose dexmedetomidine supplemented intravenous analgesia on sleep structure in older patients after major noncardiac surgery: A randomized trial

STUDY OBJECTIVES

In previous studies, low-dose dexmedetomidine supplemented opioid analgesia improved sleep architecture but increased sedation level. Herein we tested the hypothesis that mini-dose dexmedetomidine supplemented analgesia improves sleep structure without increasing sedation.

METHODS

In this randomized trial, 118 older patients (≥65 years) following major noncardiac surgery were randomized to receive patient-controlled intravenous analgesia supplemented with either placebo or dexmedetomidine (median 0.02 μg kg^-1 h^-1) for up to 3 days. Polysomnogram was monitored from 9:00 p.m. on the day of surgery until 6:00 a.m. on the first day after surgery. Our primary outcome was the percentage of non-rapid eye movement stage 2 (N2) sleep. Secondary outcomes included other sleep structure parameters during the night of surgery and the sedation score during the first five postoperative days.

RESULTS

All 118 patients completed the study; of these, 85 were included in sleep structure analysis. Dexmedetomidine supplemented analgesia increased the percentage of N2 sleep (median difference, 10%; 95% CI, 1%-20%; P = 0.03). It also prolonged total sleep time (median difference, 78 min; 95% CI, 21 to 143; P = 0.01), increased sleep efficiency (median difference, 14%; 95% CI, 4%-26%; P = 0.01), decreased percentage of N1 sleep (median difference, -10%; 95% CI, -20% to -1%; P = 0.04), and lowered sleep fragmentation index (median difference, -1.6 times⋅h^-1; 95% CI, -3.7 to 0.1; P = 0.04). Sedation score within 5 days did not differ between the two groups.

CONCLUSIONS

Supplementing intravenous analgesia with mini-dose dexmedetomidine improved sleep structure without increasing sedation in older patients recovering from major surgery.

CLINICAL TRIALS

www.

CLINICALTRIALS

gov (NCT03117790), registered 2 April 2017.

Research progress on risk factors of delirium in burn patients: A narrative review

Delirium, an acute brain dysfunction, is a common and serious complication in burn patients. The occurrence of delirium increases the difficulty of patient treatment, is associated with various adverse outcomes, and increases the burden on the patient's family. Many scholars have studied the factors that cause delirium, but the causes, pathogenesis, and treatment of delirium in burn patients have not been fully revealed. There is no effective pharmacological treatment for delirium, but active preventive measures can effectively reduce the incidence of delirium in burn patients. Therefore, it is necessary to study the relevant factors affecting the occurrence of delirium in burn patients. This study was conducted on December 20, 2021 by searching the PubMed database for a narrative review of published studies. The search strategy included keywords related to "burns," "delirium," and "risk factors." We reviewed the characteristics of delirium occurrence in burn patients and various delirium assessment tools, and summarized the risk factors for the development of delirium in burn patients in terms of personal, clinical, and environmental factors, and we found that although many risk factors act on the development of delirium in burn patients, some of them, such as clinical and environmental factors, are modifiable, suggesting that we can estimate the exposure of burn patients to risk factors by assessing their likelihood of delirium occurring and to make targeted interventions that provide a theoretical basis for the prevention and treatment of burn delirium.

Development and validation of prediction models for neurocognitive disorders in adult patients admitted to the ICU with sleep disturbance

BACKGROUND

Neurocognitive disorders (NCDs) and sleep disturbance are highly prevalent in the perioperative period and intensive care unit (ICU). There has been a lack of individualized evaluation tools designed for the high-risk NCDs in critically ill patients with sleep disturbance.

OBJECTIVES

The aim of this study was to develop and validate prediction models for NCDs among adult patients with sleep disturbance.

METHODS

The R software was used to analyze the dataset of adult patients admitted to the ICU with sleep disturbance, who were diagnosed following the codes of the International Classification of Diseases, 9th Revision (ICD-9) and 10th Revision (ICD-10) using the MIMIC-IV database. We used logistic regression and LASSO analyses to identify important risk factors associated with NCDs and develop nomograms for NCDs predictions. We measured the performances of the nomograms using the bootstrap resampling procedure, sensitivity, specificity of the receiver operating characteristic (ROC), area under the ROC curves (AUC), and decision curve analysis (DCA).

RESULTS

The prediction models shared the 10 risk factors (age, gender, midazolam, morphine, glucose, diabetes diseases, potassium, international normalized ratio, partial thromboplastin time, and respiratory rate). Cardiovascular diseases were included in the logistic regression, the sensitivity was 74.1%, and specificity was 64.6%. When platelet and Glasgow Coma Score (GCS) were included and cardiovascular diseases were removed in the LASSO prediction model, the sensitivity was 86.1% and specificity was 82.8%. Discriminative abilities of the logistic prediction and LASSO prediction models for NCDs in the validation set were evaluated as the AUC scores, which were 0.730 (95% CI 0.716-0.743) and 0.920 (95% CI 0.912-0.927). Net benefits of the prediction models were observed at threshold probabilities of 0.567 and 0.914.

CONCLUSIONS

The LASSO prediction model showed better performance than the logistic prediction model and should be preferred for nomogram-assisted decisions on clinical risk management of NCDs among adult patients with sleep disturbance in the ICU.