Melatonin and melatonin agonist for delirium in the elderly patients

The relationship between anesthesia and melatonin: a review

Introduction: This comprehensive review delves into the intricate and multifaceted relationship between anesthesia and melatonin, aiming to provide essential insights for perioperative clinical anesthesiologists and stimulate interest in related research. Anesthesia and surgery have the potential to disrupt melatonin secretion, leading to sleep disorders, postoperative neurocognitive dysfunction and other symptoms. In comparison to previous reviews, this review provides a comprehensive summary of the various aspects linking melatonin and anesthesia, going beyond isolated perspectives. It explores the potential benefits of administering melatonin during the perioperative period, including alleviating anxiety, reducing pain, enhancing perioperative sleep quality, as well as demonstrating immunomodulatory and anti-tumor effects, potentially offering significant advantages for cancer surgery patients. Recent Findings: Anesthesia and surgery have a significant impact on melatonin secretion, the hormone crucial for maintaining circadian rhythms. These procedures disrupt the normal secretion of melatonin, leading to various adverse effects such as sleep disturbances, pain, and postoperative neurocognitive dysfunction. However, the administration of exogenous melatonin during the perioperative period has yielded promising results. It has been observed that perioperative melatonin supplementation can effectively reduce anxiety levels, improve pain management, enhance the quality of perioperative sleep, and potentially decrease the occurrence of postoperative delirium. In recent years, studies have found that melatonin has the potential to improve immune function and exhibit anti-cancer effects, further underscoring its potential advantages for patients undergoing cancer surgery. Summary: In summary, melatonin can serve as an adjuvant drug for anesthesia during the perioperative period. Its administration has demonstrated numerous positive effects, including anti-anxiety properties, sedation, analgesia, improved postoperative sleep, and the potential to reduce the incidence of postoperative delirium. Furthermore, its immune-modulating and anti-tumor effects make it particularly valuable for cancer surgery patients. However, further studies are required to determine the optimal dosage, long-term safety, and potential adverse reactions associated with melatonin administration.

Using Machine Learning Algorithms to Predict High-Risk Factors for Postoperative Delirium in Elderly Patients

Purpose

Postoperative delirium (POD) is a common postoperative complication in elderly patients, and it greatly affects the short-term and long-term prognosis of patients. The purpose of this study was to develop a machine learning model to identify preoperative, intraoperative and postoperative high-risk factors and predict the occurrence of delirium after nonbrain surgery in elderly patients.

Patients and Methods

A total of 950 elderly patients were included in the study, including 132 patients with POD. We collected 30 characteristic variables, including patient demographic characteristics, basic medical history, preoperative examination characteristics, type of surgery, and intraoperative information. Three machine learning algorithms, multilayer perceptron (MLP), extreme gradient boosting (XGBoost), and k-nearest neighbor algorithm (KNN), were applied to construct the model, and the k-fold cross-validation method, ROC curve, calibration curve, decision curve analysis (DCA) and external validation were used for model evaluation.

Results

XGBoost showed the best performance among the three prediction models. The ROC curve results showed that XGBoost had a high area under the curve (AUC) value of 0.982 in the training set; the AUC value in the validation set was 0.924, and the prediction model was highly accurate. The k-fold cross-validation method was used for internal validation, and the XGBoost model was stable The calibration curve showed high predictive power of the XGBoost model. The DCA curve showed a higher benefit rate for patients who received interventional treatment under the XGBoost model. The AUC value for the external validation set was 0.88, indicating that the predictive model was extrapolative.

Conclusion

The prediction model of POD derived from the machine learning algorithm in this study has high prediction accuracy and clinical utility, which is beneficial for clinicians to diagnose and treat patients in a timely manner.

Current Insights into the Risks of Using Melatonin as a Treatment for Sleep Disorders in Older Adults

Exogenous melatonin is commonly used for sleep disorders in older adults, and its use is increasing over time. It appears to have modest efficacy in treating insomnia and circadian rhythm sleep-wake disorders. Melatonin is commonly perceived to be a safe alternative to other hypnotics and is available without prescription in some jurisdictions. New evidence suggests that endogenous melatonin has pleomorphic effects on multiple organ systems, many of which are poorly understood. This narrative review summarizes the current evidence regarding the safety of melatonin in older adults (defined by age over 65 years). Melatonin appears to have a favorable safety profile in this population, however there is a dearth of evidence regarding the safety of prolonged use. There are several factors which increase the risk of adverse effects of melatonin in older adults, and these should be taken into consideration when prescribing to this population.

Incidence and Risk Factors of Delirium in the Intensive Care Unit: A Prospective Cohort

Purpose

The purpose of this study was to determine the incidence, risk factors, and impact of delirium on outcomes in ICU patients. In addition, the scoring systems were measured consecutively to characterize how these scores changed with time in patients with and without delirium. Material and Methods. A prospective cohort study enrolling 400 consecutive patients admitted to the ICU between 2018 and 2019 due to trauma or surgery. Patients were followed up for the development of delirium over ICU days using the Confusion Assessment Method (CAM) for the ICU and Intensive Care Delirium Screening Checklist (ICDSC). Cox model logistic regression analysis was used to explore delirium risk factors.

Results

Delirium occurred in 108 (27%) patients during their ICU stay, and the median onset of delirium was 4 (IQR 3–4) days after admission. According to multivariate cox regression, the expected hazard for delirium was 1.523 times higher in patients who used mechanical ventilator as compared to those who did not (HR: 1.523, 95% CI: 1.197-2.388, P < 0.001).

Conclusion

Our findings suggest that an important opportunity for improving the care of critically ill patients may be the determination of modifiable risk factors for delirium in the ICU. In addition, the scoring systems (APACHE IV, SOFA, and RASS) are useful for the prediction of delirium in critically ill patients.

Melatonin and its analogues for the prevention of postoperative delirium: A systematic review and meta-analysis

It remains unclear whether melatonin and its analogues prevent postoperative delirium (POD). Therefore, we conducted a systematic review and meta-analysis to evaluate the effect of melatonin and its analogues on POD prevention. PubMed, Cochrane Library, Web of Science, Embase and CINAHL databases were searched. Primary outcome was the incidence of POD. Six randomized controlled trials, 2 cohort studies and 1 case-control study were included in this meta-analysis. Results showed that melatonin and its analogue ramelteon decreased the incidence of POD in the entire adult surgical population (odds ratio [OR] = 0.45, 95% confidence interval [CI] 0.24-0.84, P = .01). When administered at a higher dose (5 mg), melatonin was effective in reducing the POD incidence (OR = 0.32, 95% CI 0.20-0.52, P < .00001). Melatonin administered less than 5 elimination half-lives before the surgery significantly reduced the POD incidence (OR = 0.31, 95% CI 0.19-0.49, P < .00001). Current literature supports the effectiveness of melatonin and its analogue ramelteon in POD prevention. However, the present study was limited by the significant heterogeneity of the included studies. More studies are needed to ascertain the preventive effect of melatonin and its analogues on the incidence of delirium after cardiac and noncardiac surgeries.

Ramelteon in the Treatment of Delirium: New Perspectives from Reported Findings and a Case Observation

:

Ramelteon is a melatonin receptor agonist that is approved for the treatment of insomnia. It is widely used due to its relatively benign side effect profile and lack of dependence or withdrawal. Due to its tolerability, clinicians have attempted to utilize ramelteon to normalize the sleep/wake patterns in patients with delirium as a safer alternative to antipsychotics or other medications. We present the case of a 75-year-old man with long-standing dementia who was hospitalized due to mental status changes, agitation, and sleep disturbance. After addressing possible underlying causes with minimal improvement, the team initiated treatment with ramelteon (8mg nightly) which resulted in rapid improvement of symptoms. Uses and mechanisms of action of ramelteon will be reviewed, as well as current pharmacologic treatments of delirium. Prior research studies and case reports regarding the use of ramelteon in the treatment of delirium will be discussed and suggestions made regarding possible areas of future study.

Melatonin, temazepam and placebo in hospitalised older patients with sleeping problems (MATCH): a study protocol of randomised controlled trial

INTRODUCTION

Hospitalised older patients frequently suffer from inadequate sleep, which can lead to patient distress and delayed recovery from acute illness or surgical procedure. Currently, no evidence-based treatments exist for sleeping problems in hospitalised older patients. Benzodiazepines, such as temazepam, are regularly prescribed by physicians, although they have serious side effects; for older patients in particular. Melatonin is proposed as a safe alternative for sleeping problems in hospitalised older patients, but the efficacy of melatonin is unclear in this population. Therefore, the aim of this study is to investigate the effects of melatonin and temazepam compared with placebo on sleep quality among hospitalised older patients with sleeping problems.

METHODS AND ANALYSIS

This study is a multicentre, randomised, placebo-controlled trial. A total of 663 patients will be randomised in a 1:1:1 fashion to receive either melatonin (n=221), temazepam (n=221) or placebo (n=221). The study population consists of hospitalised patients aged 60 years and older, with new or aggravated sleeping problems for which an intervention is needed. The primary outcome is sleep quality measured with the Leeds Sleep Evaluation Questionnaire (LSEQ). Secondary outcomes include sleep parameters measured with actigraphy and medication-related adverse effects.

ETHICS AND DISSEMINATION

This study was approved by the Medical Ethics Committee of the Academic Medical Centre Amsterdam, (No 2015_302). Study findings will be disseminated through presentations at professional and scientific conferences and publications in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NTR6908; Pre-results.

Melatonin and the Prevention and Management of Delirium: A Scoping Study

Background

The therapeutic benefit of melatonin in the prevention and treatment of delirium is uncertain.

Objective

To perform a scoping study to describe the existing literature regarding the use of melatonin and ramelteon in the prevention and treatment of delirium.

Methods

We performed a scoping study using the Arksey and O’Malley framework to explore our objective. Two independent panels searched MEDLINE, OVID, EMBASE, PubMed, Google Scholar, and Cochrane Library for relevant articles up to November 2017 describing the use of melatonin and ramelteon in the prevention or management of delirium. We extracted relevant summary data from the studies and attempted to draw conclusion regarding benefit.

Results

We summarized evidence from 20 relevant articles. There were a total of nine articles: five randomized controlled trials (RCTs), two retrospective medical record reviews, one non-randomized observational study, and one case report describing the role of either melatonin or ramelteon in preventing delirium. There were a total of 11 studies studying the role of either melatonin or ramelteon in the management of established delirium. None of these were RCT and were predominantly case series and case reports. Four of the five trials studying the effect of melatonin analogs in preventing delirium reported a beneficial effect but study heterogeneity limited any broad recommendations. Similarly, the lack of any well-designed trials limits any recommendations regarding the effect of melatonin analogs in treating delirium.

Conclusion

Large, well-designed clinical trials are required to explore the potential beneficial effects of melatonin and ramelteon on delirium prevention and management.

Delirium in the elderly: A systematic review of pharmacological and non-pharmacological treatments

Delirium is a common disorder associated with poor prognosis, especially in the elderly. The impact of different treatment approaches for delirium on morbimortality and long-term welfare is not completely understood.

OBJECTIVE

To determine the efficacy of pharmacological and non-pharmacological treatments in elderly patients with delirium.

METHODS

This systematic review compared pharmacological and non-pharmacological treatments in patients over 60 years old with delirium. Databases used were: MEDLINE (PubMed), EMBASE, Cochrane CENTRAL and LILACS from inception to January 6^th, 2016.

RESULTS

A total of ten articles were selected. The six non-pharmacological intervention studies showed no impact on duration of delirium, mortality or institutionalization, but a decrease in severity of delirium and improvement in medium-term cognitive function were observed. The most commonly used interventions were temporal-spatial orientation, orientation to self and others, early mobilization and sleep hygiene. The four studies with pharmacological interventions found that rivastigmine reduced the duration of delirium, improved cognitive function and reduced caregiver burden; olanzapine and haloperidol decreased the severity of delirium; droperidol reduced length of hospitalization and improved delirium remission rate.

CONCLUSION

Although the pharmacological approach has been used in the treatment of delirium among elderly, there have been few studies assessing its efficacy, involving a small number of patients. However, the improvements in delirium duration and severity suggest these drugs are effective in treating the condition. Once delirium has developed, non-pharmacological treatment seems less effective in controlling symptoms, and there is a lack of studies describing different non-pharmacological interventions.

Sleep-wake cycle disturbances in elderly acute general medical inpatients: Longitudinal relationship to delirium and dementia

INTRODUCTION

Sleep disturbances in elderly medical inpatients are common, but their relationship to delirium and dementia has not been studied.

METHODS

Sleep and delirium status were assessed daily for a week in 145 consecutive newly admitted elderly acute general hospital patients using the Delirium Rating Scale-Revised-98 (DRS-R98), Diagnostic and Statistical Manual 5, and Richards-Campbell Sleep Quality Scale measures. The longitudinal relationship between DRS-R98 and Richards-Campbell Sleep Quality Scale sleep scores and delirium, also with dementia as a covariate, was evaluated using generalized estimating equation logistic regression.

RESULTS

The cohort was divided into delirium only, dementia only, comorbid delirium-dementia, and no-delirium/no-dementia subgroups. Mean age of total group was 80 ± 6.3, 48% were female, and 31 (21%) had dementia, 29 had delirium at admission (20%), and 27 (18.5%) experienced incident delirium. Mild sleep disturbance (DRS-R98 sleep item score ≥1) occurred for at least 1 day in all groups, whereas moderate sleep disturbance (score ≥2) occurred in significantly more of the prevalent delirium-only (81%; n = 17) cases than incident delirium-only (46%; n = 13) cases (P < .001). There were more cases with DRS-R98 sleep item scores ≥2 (P < .001) in the delirium-only group compared with the other subgroups. Severity of sleep-wake cycle disturbance over time was significantly associated with Diagnostic and Statistical Manual 5 delirium status but not with age, sex, or dementia (P < .001).

CONCLUSIONS

Observer-rated more severe sleep-wake cycle disturbances are highly associated with delirium irrespective of dementia status, consistent with being a core feature of delirium. Monitoring for altered sleep-wake cycle patterns may be a simple way to improve delirium detection.

Melatonin Supplementation May Improve the Outcome of Patients with Hemorrhagic Stroke in the Intensive Care Unit

Objective:

Although mechanical ventilation is frequently a life-saving therapy, its use can result in unwanted side effects. It has been well documented that the choice of sedating agent may influence the duration of mechanical ventilation. Melatonin is a sedative and analgesic agent without any respiratory depressant effect which makes it an attractive adjuvant for sedation in the intubated patients. The aim of this study is to evaluate the effect of melatonin on the duration of mechanical ventilation in patients with hemorrhagic stroke.

Methods:

Forty adult intubated patients with hemorrhagic stroke, who were admitted to the Intensive Care Unit (ICU) within 24 h of onset, were enrolled in this randomized double-blind study. Subjects in the melatonin group received 30 mg of melatonin every night throughout the nasogastric tube. Length of ICU stay, mortality, and duration of mechanical ventilation were recorded for all patients.

Findings:

The duration of mechanical ventilation and length of ICU stay were shorter in patients who received melatonin in comparison with the control group, and this difference was statistically significant for the length of ICU stay and marginally significant for the duration of mechanical ventilation. Although not statistically significant, the mortality rate of the control group was 30%, almost double that of the study group (15%).

Conclusion:

Melatonin possesses hypnotic, analgesic, anti-inflammatory, and anti-oxidative properties that distinguish it as an attractive adjuvant in patients under mechanical ventilation. In conclusion, the administration of melatonin may facilitate the weaning process through decreasing the consumption of sedatives with respiratory depressant properties as well as preventing ventilator-associated lung injury.

Circadian Rhythm Disruption in the Critically Ill: An Opportunity for Improving Outcomes

OBJECTIVES

Circadian rhythms are severely disrupted among the critically ill. These circadian arrhythmias impair mentation, immunity, autonomic function, endocrine activity, hormonal signaling, and ultimately healing. In this review, we present a modern model of circadian disruption among the critically ill, discuss causes of these circadian arrhythmias, review observational and intervention studies of the effects of circadian-rhythm-restoring factors on medical outcomes, and identify needed key trials of circadian interventions in the critically ill.

DATA SOURCES

MEDLINE, EMBASE, PsychINFO, Google Scholar through December 2014.

STUDY SELECTION

Articles relevant to circadian rhythms, melatonin, and light in the critically ill were selected.

DATA EXTRACTION AND DATA SYNTHESIS

Articles were synthesized for this review of circadian arrhythmia and the use of circadian-rhythm-restoring interventions among the critically ill.

CONCLUSIONS

Circadian disruption often demonstrates serial degradation: initially, the amplitude attenuates along with delayed circadian phase. With increasing acuity of illness, circadian rhythmicity may be lost entirely. Causes of chronodisruption may be environmental or internal to the patient. In particular, inadequate daytime illumination and nocturnal light pollution disrupt healthy circadian periodicity. Internal causes of circadian arrhythmia include critical illness itself and subjective experience of distress and pain. Observational studies of windowed rooms and real-time ambient lighting have found that physiologic light-dark patterns may support recovery from critical illness. Studies of early morning bright light or evening melatonin agonists have found improved rates of delirium, enhanced sleep, and lower arrhythmia prevalence. The current evidence base emphasizes that lighting and melatoninergic interventions deserve to be tested in full-scale trials.

Missed Opportunities for Intervention in a Patient With Prolonged Postoperative Delirium

PURPOSE

Postoperative delirium is a common and costly state of brain dysfunction that complicates postsurgical management in some patients. The purpose of this report was to describe a case of prolonged postoperative delirium and to review the appropriate identification and management of this condition.

METHODS

A 56-year-old female patient who presented with newly diagnosed diabetes mellitus and dry gangrene underwent a vascular bypass procedure while under general anesthesia. After extubation, the patient became disoriented and agitated.

FINDINGS

The delirium continued in a hypoactive form for 10 days before it progressed to severe agitation. During the patient's 2-month hospitalization, she underwent 6 additional surgeries. Eventually, the delirium improved with the use of antipsychotic agents, and the patient was discharged to a skilled nursing facility.

IMPLICATIONS

This patient's history, medications, and anesthetic and surgical exposure placed her at high risk for postoperative delirium. Her exceptionally prolonged course of postoperative delirium was likely perpetuated by a multitude of factors, including the continued use of high-risk medications, the stress of repeated surgeries, urinary issues, and infection.

CONCLUSION

In this high-risk patient, a proactive approach to the prevention and treatment of delirium may have avoided or mitigated the prolonged delirium and, potentially, long-term cognitive deficits.

Management of delirium in palliative care: a review

Delirium is a complex but common disorder in palliative care with a prevalence between 13 and 88 % but a particular frequency at the end of life (terminal delirium). By reviewing the most relevant studies (MEDLINE, EMBASE, PsycLit, PsycInfo, Cochrane Library), a correct assessment to make the diagnosis (e.g., DSM-5, delirium assessment tools), the identification of the possible etiological factors, and the application of multicomponent and integrated interventions were reported as the correct steps to effectively manage delirium in palliative care. In terms of medications, both conventional (e.g., haloperidol) and atypical antipsychotics (e.g., olanzapine, risperidone, quetiapine, aripiprazole) were shown to be equally effective in the treatment of delirium. No recommendation was possible in palliative care regarding the use of other drugs (e.g., α-2 receptors agonists, psychostimulants, cholinesterase inhibitors, melatonergic drugs). Non-pharmacological interventions (e.g., behavioral and educational) were also shown to be important in the management of delirium. More research is necessary to clarify how to more thoroughly manage delirium in palliative care.