Sleep quality and its association with delirium among veterans enrolled in hospice

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.

Cognitive recovery trajectories 3 months following stroke in Mexican American and non-Hispanic white adults

OBJECTIVES

We examined whether cognitive trajectories from 0-3 months after stroke differ between Mexican Americans (MAs) and non-Hispanic white (NHW) adults.

MATERIALS AND METHODS

The sample included 701 participants with ischemic stroke (62% MA; 38% NHW) from the population-based stroke surveillance study, the Brain Attack Surveillance in Corpus Christi (BASIC) Project, between 2008-2013. The outcome was the modified Mini Mental State Examination (3MSE, range 0-100 lower scores worse). Linear mixed effects models were utilized to examine the association between ethnicity and cognitive trajectories from 0-3 months following stroke, adjusting for confounders.

RESULTS

MAs were younger, had lower educational attainment, and fewer had health insurance than NHWs (all p< 0.01). A smaller proportion of MAs were rated by informants as exhibiting pre-stroke cognitive decline than NHW (p < .0.05). After accounting for confounders, MAs demonstrated lower cognitive performance at post-stroke baseline and at 3-months following stroke (-2.00; 95% CI =-3.92, -0.07). Cognitive trajectories from 0-3 months following stroke were indicative of modest cognitive recovery (increase of 0.034/day, 95% CI =0.030-0.036) and did not differ between MAs and NHWs (p = 0.68).

CONCLUSION

We found no evidence that cognitive trajectories in the first three months following stroke differed between MAs and NHWs. MAs demonstrated lower cognitive performance shortly after stroke and at three months following stroke compared to NHWs. Further research is needed to identify factors contributing to ethnic disparities in cognitive outcomes after stroke.

Predisposing and Precipitating Factors Associated With Delirium: A Systematic Review

IMPORTANCE

Despite discrete etiologies leading to delirium, it is treated as a common end point in hospital and in clinical trials, and delirium research may be hampered by the attempt to treat all instances of delirium similarly, leaving delirium management as an unmet need. An individualized approach based on unique patterns of delirium pathophysiology, as reflected in predisposing factors and precipitants, may be necessary, but there exists no accepted method of grouping delirium into distinct etiologic subgroups.

OBJECTIVE

To conduct a systematic review to identify potential predisposing and precipitating factors associated with delirium in adult patients agnostic to setting.

EVIDENCE REVIEW

A literature search was performed of PubMed, Embase, Web of Science, and PsycINFO from database inception to December 2021 using search Medical Subject Headings (MeSH) terms consciousness disorders, confusion, causality, and disease susceptibility, with constraints of cohort or case-control studies. Two reviewers selected studies that met the following criteria for inclusion: published in English, prospective cohort or case-control study, at least 50 participants, delirium assessment in person by a physician or trained research personnel using a reference standard, and results including a multivariable model to identify independent factors associated with delirium.

FINDINGS

A total of 315 studies were included with a mean (SD) Newcastle-Ottawa Scale score of 8.3 (0.8) out of 9. Across 101 144 patients (50 006 [50.0%] male and 49 766 [49.1%] female patients) represented (24 015 with delirium), studies reported 33 predisposing and 112 precipitating factors associated with delirium. There was a diversity of factors associated with delirium, with substantial physiological heterogeneity.

CONCLUSIONS AND RELEVANCE

In this systematic review, a comprehensive list of potential predisposing and precipitating factors associated with delirium was found across all clinical settings. These findings may be used to inform more precise study of delirium's heterogeneous pathophysiology and treatment.

Risk factors for delirium in adult patients receiving specialist palliative care: A systematic review and meta-analysis

BACKGROUND

Delirium is common and distressing for patients receiving palliative care. Interventions targetting modifiable risk factors in other settings have been shown to prevent delirium. Research on delirium risk factors in palliative care can inform context-specific risk-reduction interventions.

AIM

To investigate risk factors for the development of delirium in adult patients receiving specialist palliative care.

DESIGN

Systematic review and meta-analysis (PROSPERO CRD42019157168).

DATA SOURCES

CINAHL, Cochrane Database of Systematic Reviews, Embase, MEDLINE and PsycINFO (1980-2021) were searched for studies reporting the association of risk factors with delirium incidence/prevalence for patients receiving specialist palliative care. Study risk of bias and certainty of evidence for each risk factor were assessed.

RESULTS

Of 28 included studies, 16 conducted only univariate analysis, 12 conducted multivariate analysis. The evidence for delirium risk factors was limited with low to very low certainty.

POTENTIALLY MODIFIABLE RISK FACTORS

Opioids and lower performance status were positively associated with delirium, with some evidence also for dehydration, hypoxaemia, sleep disturbance, liver dysfunction and infection. Mixed, or very limited, evidence was found for some factors targetted in multicomponent prevention interventions: sensory impairments, mobility, catheter use, polypharmacy (single study), pain, constipation, nutrition (mixed evidence).

NON-MODIFIABLE RISK FACTORS

Older age, male sex, primary brain cancer or brain metastases and lung cancer were positively associated with delirium.

CONCLUSIONS

Findings may usefully inform interventions to reduce delirium risk but more high quality prospective cohort studies are required to enable greater certainty about associations of different risk factors with delirium during specialist palliative care.

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.

Sleep problems in advanced disease

Sleep problems are relatively common in patients with advanced disease, and are associated with significant morbidity in these groups of patients. The focus of this article is sleep problems in patients with advanced cancer, and specifically insomnia, 'vivid' dreams and nightmares. However, other sleep problems are also relatively common in this group of patients, including sleep-related breathing disorders and circadian rhythm sleep-wake disorders. Healthcare professionals should screen all patients with advanced diseases for sleep problems and, equally, initiate appropriate (evidence-based) interventions when they are discovered.

A Scoping Review to Map Empirical Evidence Regarding Key Domains and Questions in the Clinical Pathway of Delirium in Palliative Care

CONTEXT

Based on the clinical care pathway of delirium in palliative care (PC), a published analytic framework (AF) formulated research questions in key domains and recommended a scoping review to identify evidence gaps.

OBJECTIVES

To produce a literature map for key domains of the published AF: screening, prognosis and diagnosis, management, and the health-related outcomes.

METHODS

A standard scoping review framework was used by an interdisciplinary study team of nurse- and physician-delirium researchers, an information specialist, and review methodologists to conduct the review. Knowledge user engagement provided context in refining 19 AF questions. A peer-reviewed search strategy identified citations in Medline, PsycINFO, Embase, and CINAHL databases between 1980 and 2018. Two reviewers independently screened records for inclusion using explicit study eligibility criteria for the population, design, delirium diagnosis, and investigational intent.

RESULTS

Of 104 studies reporting empirical data and meeting eligibility criteria, most were conducted in patients with cancer (73.1%) and in inpatient PC units (52%). The most frequent study design was a one or more group, nonrandomized trial or cohort (67.3%). Evidence gaps were identified: delirium risk prediction; comparative effectiveness and harms of prevention, variability in delirium management across PC settings, advanced directive and substitute decision-maker input, and transition of care location; and estimating delirium reversibility. Future rigorous primary studies are required to address these gaps and preliminary concerns regarding the quality of extant literature.

CONCLUSION

Substantial evidence gaps exist, providing opportunities for future research regarding the assessment, prognosis, and management of delirium in PC settings.

Improve postoperative sleep: what can we do?

Purpose of review

We reviewed evidences regarding occurrence, risk factors, harmful effects, prevention, and management of sleep disturbances in patients after surgery.

Recent findings

Normal sleep is important to maintain physical and mental health. Sleep disturbances frequently occur in patients after surgery. Factors associated with the development of postoperative sleep disturbances include old age, preoperative comorbidity, type of anesthesia, severity of surgical trauma, postoperative pain, environment stress, as well as other factors leading to discomfort of patients. Development of sleep disturbances produces harmful effects on postoperative patients, that is, leading to higher risk of delirium, increased sensitivity to pain, more cardiovascular events, and poorer recovery. Both nonpharmacological and pharmacological measures (such as zolpidem, melatonin, and dexmedetomidine) can be used to improve postoperative sleep. Recent evidences show that sleep promotion may improve patients’ outcome, but requires further evidences.

Summary

Sleep disturbances are common in patients after surgery and produce harmful effects on postoperative recovery. Sleep-promotion therapy may be helpful to improve postoperative recovery, but long-term effects deserve further study.

Sleep Disruption at Home As an Independent Risk Factor for Postoperative Delirium

OBJECTIVES

To determine whether sleep disruption at home or in hospital is an independent risk factor for postoperative delirium in older adults undergoing elective surgery.

DESIGN

Prospective cohort study.

SETTING

German teaching hospital.

PARTICIPANTS

Individuals aged 65 and older undergoing elective arthroplasty (N = 101).

MEASUREMENTS

Preoperative questionnaires were used to assess sleep disruption at home (Pittsburgh Sleep Quality Index). Actigraphy was used to objectively measure sleep disruption in the hospital before and after surgery. Delirium was assessed daily after surgery using the Confusion Assessment Method and, if there was uncertainty, validated according to International Classification of Diseases, Tenth Revision (ICD-10), criteria.

RESULTS

Twenty-seven participants developed postoperative delirium. Those with sleep disruption at home were 3.26 times as likely to develop postoperative delirium as those without (95% confidence interval (CI) = 1.34-7.92, P = .009). Participants with sleep disruption in hospital were 1.21 times as likely to develop postoperative delirium as those without (95% CI = 1.03-1.41, P = .02). When adjusting for other variables, risk remained significant for sleep disruption at home (risk ratio (RR) = 3.90, 95% CI = 2.14-7.11, P < .001) but not in the hospital (RR = 1.19, 95% CI = 0.69-2.07). Jointly modeling sleep disruption at home and in the hospital, adjusted for covariates, resulted in significant contributions of both (home: RR = 3.10, 95% CI = 1.34-7.17, P = .008; hospital: RR = 1.38 95% CI = 1.13-1.68, P = .002).

CONCLUSIONS

Older people with sleep disruption at home are at significantly higher risk of developing postoperative delirium than those without. Sleep disruption in the hospital may further heighten this risk.

A change in sleep pattern may predict Alzheimer disease

OBJECTIVE

Sleep problems may adversely affect neuronal health. We examined a subjective report of change (reduced duration and/or depth) in sleep pattern in relation to subsequent risk of incident all-cause dementia and Alzheimer disease (AD) over 9 years.

METHODS

This longitudinal study used data from a population-based sample of 214 Swedish adults aged 75 and over who were dementia-free both at baseline and at first follow-up (3 years later). The sample was 80% female and, on average, 83.4 years of age at baseline. All participants underwent a thorough clinical examination to ascertain all-cause dementia and AD.

RESULTS

Forty percent of participants reported a change in sleep duration at baseline. Between the 6th and 9th year after baseline, 28.5% were diagnosed with all-cause dementia, 22.0% of whom had AD. Reduced sleep was associated with a 75% increased all-cause dementia risk (hazard ratio: 1.75; 95% confidence interval: 1.04-2.93; Wald = 4.55, df = 1, p = 0.035) and double the risk of AD (hazard ratio: 2.01; 95% confidence interval: 1.12-3.61; Wald = 5.47, df = 1, p = 0.019) after adjusting for age, gender, and education. The results remained after adjusting for lifestyle and vascular factors but not after adjusting for depressive symptoms. No evidence supported a moderating effect of the use of sleeping pills, and the sleep-dementia relationship remained after controlling for the presence of the apolipoprotein E ε4 allele.

CONCLUSION

Self-reported sleep problems may increase the risk for dementia, and depressive symptoms may explain this relationship. Future research should determine whether treatment, in particular, behavioral or nonpharmacologic treatment, may represent one avenue toward reduction of dementia risk in late life.

The Use of Pentobarbital in Cases of Severe Delirium

Delirium is a common syndrome present at the end of life and causes significant distress for patients and families. Sleep disruption is a common precipitating factor for delirium and restoration of sleep may be instrumental in attenuating symptoms. In this cases series, we present three patients who were unresponsive to escalating doses of standard delirium medications, but whose delirium resolved once improved sleep was achieved using Pentobarbital. In a fourth patient, delirium was successfully treated where neuroleptics were contraindicated. Pentobarbital has been shown to reduce the time to sleep onset, decrease the number of body movements during sleep and spontaneous awakenings and increase the total sleep time. Pentobarbital may provide an additional treatment option for patients whose delirium is refractory to standard management approaches.