Loss of melatonin daily rhythmicity is asociated with delirium development in hospitalized older adults

Does Melatonin Decrease the Use of As-Needed Antipsychotics or Benzodiazepines in Noncritically Ill Hospitalized Patients? A Multicenter Retrospective Cohort Study

Background: Delirium is a common neuropsychiatric syndrome without an FDA-approved treatment. Commonly used modalities show little improvement in outcomes; therefore, prevention efforts are imperative. Abnormalities in the sleep/wake cycle have been linked to delirium, and melatonin has been proposed to replace the hypothesized low levels of endogenous melatonin and restore sleep/wake cycle synchronization. Objectives: The primary objective of this study was to evaluate the association between melatonin, benzodiazepines (BZDs) or zolpidem (ZLP), and the use of as-needed antipsychotics and BZDs for delirium in noncritically ill adult patients. Methods: This was a multicenter retrospective cohort study of noncritically ill adult patients admitted to two separate health systems from August 2012 to December 2018 receiving either melatonin or nonmelatonin medications (ZLP or BZDs) for sleep. The coprimary endpoint was the proportion of patients receiving a pro re nata (PRN) antipsychotic or BZD 5 days from the patient's first dose of melatonin, BZD, or ZLP. Secondary outcomes included evaluation of the coprimary outcome in patients 65 years of age or older, total number of PRN antipsychotic and BZD doses, and length of stay. Results: Two hundred and twenty-five patients were included in the final analysis. Administration of BZD or ZLP was associated with a higher risk of subsequent BZD administration as compared with melatonin (OR 2.78, 95% CI 1.2-1.87) and ZLP (OR 2.78, 95% CI 1.25-6.17). BZD or ZLP had no impact on PRN antipsychotic use compared with melatonin (OR 1.09, 95% CI 0.51-2.35) and ZLP (OR 1.16, 95% CI 0.56-2.4). Conclusion: Melatonin use was found to be associated with a significant decrease in PRN BZD use in noncritically ill patients hospitalized on general floors; however, there was no observed association with overall PRN antipsychotic use. These results suggest that using melatonin may help decrease utilization of medications commonly used to manage delirium.

Melatonin does not reduce delirium severity in hospitalized older adults: Results of a randomized placebo-controlled trial

BACKGROUND

Delirium is common in older inpatients, causing distress, cognitive decline, and death. Current therapies are unsatisfactory, limited by lack of efficacy and adverse effects. There is an urgent need for effective delirium treatment. Sleep wake cycle is disturbed in delirium; endogenous Melatonin is perturbed, and exogenous Melatonin is a safe and effective medication for sleep disorders. This study aims to determine the effect of oral Melatonin 5 mg immediate release (IR) nightly for five nights on the severity of delirium in older (≥65 years) medical inpatients.

METHODS

This was a double-blinded, randomized controlled trial in general internal medicine units of a tertiary teaching hospital. Older inpatients with Confusion Assessment Method positive, hyperactive or mixed delirium within 48 h of admission or onset of in-hospital delirium were included. The primary outcome was change in delirium severity measured with the Memorial Delirium Assessment Scale (MDAS). A previous pilot trial showed 120 participants randomized 1:1 to Melatonin or Placebo would provide 90% power to demonstrate a 3-point reduction in the MDAS.

RESULTS

One hundred and twenty participants were randomized, 61 to Melatonin 5 mg and 59 to Placebo. The medication was well tolerated. The mean MDAS improvement was 4.9 (SD 7.6) in the Melatonin group and 5.4 (SD 7.2) in the Placebo group, p-value 0.42, a non-significant difference. A post-hoc analysis showed length of stay (LOS) was shorter in the intervention group (median 9 days [Interquartile Range (IQR) 4, 12] vs. Placebo group 10 [IQR 6, 16] p-value = 0.033, Wilcoxon Rank Sum test).

CONCLUSIONS

This trial does not support the hypothesis that Melatonin reduces the severity of delirium. This may be due to no effect of Melatonin, a smaller effect than anticipated, an effect not captured on a multidimensional delirium assessment scale, or a type II statistical error. Melatonin may improve LOS; this hypothesis should be studied.

Sleep in the intensive and intermediate care units: Exploring related factors of delirium, benzodiazepine use and mortality

AIM OF THE STUDY

The primary purpose was to examine sleep difficulties and delirium in the Intensive and Intermediate Care Unit. Secondarily, factors impacting night-time sleep duration and quality, mortality, and the impact of benzodiazepine use on sleep outcomes were investigated.

MATERIALS AND METHODS

This retrospective study encompassed data from 323 intensive and intermediate care unit admissions collected in the Netherlands, spanning from November 2018 to May 2020. Sleep quality was measured using the Richards-Campbell Sleep Questionnaire. Night-time sleep duration was nurse-reported. We investigated associations of these sleep outcomes with age, sex, length-of-stay, natural daylight, disease severity, mechanical ventilation, benzodiazepine use, and delirium using Generalized Estimating Equations models. Associations with one-year post-discharge mortality were analyzed using Cox regression.

RESULTS

Night-time sleep duration was short (median 4.5 hours) and sleep quality poor (mean score 4.9/10). Benzodiazepine use was common (24 % of included nights) and was negatively associated with night-time sleep duration and quality (B = -0.558 and -0.533, p <.001). Delirium and overnight transfers were negatively associated with sleep quality (B = -0.716 and -1.831, p <.05). The day-to-night sleep ratio was higher in the three days before delirium onset than in non-delirious individuals (p <.05). Age, disease severity and female sex were associated with increased one-year mortality. Sleep quality was negatively, but not-significantly, associated with mortality (p =.070).

CONCLUSIONS

Night-time sleep in the critical care environment has a short duration and poor quality. Benzodiazepine use was not associated with improved sleep. Sleep patterns change ahead of delirium onset.

IMPLICATIONS FOR CLINICAL PRACTICE

Consistent sleep monitoring should be part of routine nursing practice, using a validated instrument like the Richards-Campbell Sleep Questionnaire. Given the lack of proven efficacy of benzodiazepines in promoting sleep in critical care settings, it is vital to develop more effective sleep treatments that include non-benzodiazepine medication and sleep hygiene strategies.

Circadian rhythm disturbance and delirium in ICU patients: a prospective cohort study

BACKGROUND

Patients treated in the intensive care unit (ICU) may experience a reversal of day and night. The circadian rhythm in ICU patients can be disturbed.

METHODS

To explore the relationship between ICU delirium and the circadian rhythms of melatonin, cortisol and sleep. A prospective cohort study was carried out in a surgical ICU of a tertiary teaching hospital. Patients who were conscious during the ICU stay after surgery and were scheduled to stay in the ICU for more than 24 h were enrolled. Serum melatonin and plasma cortisol levels were measured three times a day by drawing arterial blood on the first three days after ICU admission. Daily sleep quality was assessed by the Richard-Campbell Sleep Questionnaire (RCSQ). The Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) was performed twice a day to screen for ICU delirium.

RESULTS

A total of 76 patients were included in this study, and 17 patients developed delirium during their ICU stay. Melatonin levels were different at 8:00 (p = 0.048) on day 1, at 3:00 (p = 0.002) and at 8:00 (p = 0.009) on day 2, and at all three time points on day 3 (p = 0.032, 0.014, 0.047) between delirium and non-delirium patients. The plasma cortisol level in the delirium patients was significantly lower than that in the non-delirium patients at 16:00 on day 1 (p = 0.025). The changes in melatonin and cortisol secretion levels exhibited obvious biological rhythmicity in non-delirium patients (p < 0.001 for melatonin, p = 0.026 for cortisol), while no rhythmicity was found in melatonin and cortisol secretion levels in the delirium group (p = 0.064 for melatonin, p = 0.454 for cortisol). There was no significant difference in RCSQ scores in the first three days between the two groups.

CONCLUSIONS

The disturbance of the circadian rhythm of melatonin and cortisol secretion was associated with the development of delirium in ICU patients. Clinical staff should pay more attention to the importance of maintaining patients' normal circadian rhythms in the ICU.

TRIAL REGISTRATION

The study was registered with the US National Institutes of Health ClinicalTrials.gov(NCT05342987) (25/04/2022).

Circadian Rest-Activity Rhythms, Delirium Risk, and Progression to Dementia

OBJECTIVE

Delirium is a complex neurocognitive syndrome suspected to be bidirectionally linked to dementia. Circadian rhythm disturbances likely contribute to dementia pathogenesis, but whether these disturbances are related to delirium risk and progression to all-cause dementia is unknown.

METHODS

We analyzed continuous actigraphy data from 53,417 middle-aged or older UK Biobank participants during a median 5 years of follow-up. Four measures were used to characterize the 24-hour daily rest-activity rhythms (RARs): normalized amplitude, acrophase representing the peak activity time, interdaily stability, and intradaily variability (IV) for fragmentation of the rhythm. Cox proportional hazards models examined whether RARs predicted incident delirium (n = 551) and progression to dementia (n = 61).

RESULTS

Suppressed 24-hour amplitude, lowest (Q1) versus highest (Q4) quartile (hazard ratio [HR]Q1 vs Q4 = 1.94, 95% confidence interval [CI] = 1.53-2.46, p < 0.001), and more fragmented (higher IV: HRQ4 vs Q1 = 1.49, 95% CI = 1.18-1.88, p < 0.001) rhythms predicted higher delirium risk, after adjusting for age, sex, education, cognitive performance, sleep duration/disturbances, and comorbidities. In those free from dementia, each hour of delayed acrophase was associated with delirium risk (HR = 1.13, 95% CI = 1.04-1.23, p = 0.003). Suppressed 24-hour amplitude was associated with increased risk of progression from delirium to new onset dementia (HR = 1.31, 95% CI = 1.03-1.67, p = 0.03 for each 1-standard deviation decrease).

INTERPRETATION

Twenty-four-hour daily RAR suppression, fragmentation, and potentially delayed acrophase were associated with delirium risk. Subsequent progression to dementia was more likely in delirium cases with suppressed rhythms. The presence of RAR disturbances before delirium and prior to progression to dementia suggests that these disturbances may predict higher risk and be involved in early disease pathogenesis. ANN NEUROL 2023;93:1145-1157.

Melatonin and Ramelteon for the treatment of delirium: A systematic review and meta-analysis

OBJECTIVE

To assess the efficacy of melatonin and melatonergic agonist for the treatment of delirium in hospitalized patients.

METHODS

Embase, MEDLINE, PsycINFO, PubMed, CENTRAL, Cochrane Database of Systematic Reviews, TRIP Medical Database, ClinicalTrials.gov and Google were searched from inception to October 2022. Randomized controlled trials (RCT) and observational studies with any type of comparator evaluating melatonin or melatonergic agonist (ramelteon) enrolling any populations (ICU, surgery, geriatric) were included. Two reviewers independently selected and extracted data using the Cochrane risk of bias tools (RoB2 and ROBINSI).

RESULTS

Out of the 650 screened publications, three RCTs and six observational studies were included (n = 1211). All three RCTs compared melatonin to placebo, as the majority of observational studies compared melatonin or ramelteon to antipsychotics. Two RCTs reported the duration of delirium and a meta-analysis provided a statistical difference between melatonin and placebo (-1.72 days, 95% CI -2.66 to -0.77, p = 0.0004). Five observational studies reported the duration of delirium but only one reported a statistical reduction in the duration of delirium.

CONCLUSION

Although melatonin and ramelteon may be effective treatments for delirium, particularly to shorten the duration of delirium and to limit the use of rescue medication, current data is limited in number and in its quality. Clinicians should wait until higher quality data from ongoing RCTs are available before prescribing melatonin to delirious patients.

Assessment of Sleep Duration and Number of Awakenings Based on Ankle and Wrist Actigraphy in Medical Hospitalized Older Patients

BACKGROUND

Most studies performed in the hospital assess sleep using self-reports; few rely on actigraphy. Although wrist actigraphy is commonly used for sleep assessment in field studies, in-hospital assessment may be challenging and cumbersome because other more necessary monitoring devices are often attached to patients' upper limbs; these may affect interpretation of wrist activity data. Placement on the ankle may be a viable solution.

OBJECTIVE

To compare total sleep time (TST) and number of awakenings (NOA) using concomitant wrist and ankle actigraphy, as well as self-reports in a sample of older adult patients hospitalized in medical units.

METHODS

This was a prospective observational study. Objective sleep data were collected using ankle and wrist actigraphy, and subjective data using sleep diary. Repeated measures mixed model analysis was performed, adjusting for age, gender, sleep medications, symptoms severity, interaction between types of measure, and night number.

RESULTS

Twenty-one older adults (65+) wore ankle and wrist actigraphy devices and subjectively estimated sleep parameters for an average of (2.15 ± 1.01) nights, with 40 nights available for analysis. TST was lower for wrist than ankle actigraphy (F_(2,87) = 7.92, p = .0007). Neither differed from self-reports. NOA differed between all types of measure (ankle, 8.58 ± 6.66; wrist, 15.49 ± 7.47; self-report, 1.81 ± 1.83; F_(2,85) = 47.66, p < .001). No significant within-subject variations and no interaction between devices and repeated measures were found.

CONCLUSIONS

Despite differences between ankle and wrist assessments, all three methods provided consistent TST estimation within participants. Findings provide preliminary support for the use of ankle actigraphy for sleep assessment in hospital settings.

Sleep monitoring challenges in patients with neurocognitive disorders: A cross-sectional analysis of missing data from activity trackers

Background and Aims

Activity monitors, such as Fitbits®, are being used increasingly for research purposes and data have been validated in healthy community-dwelling older adults. Given the lack of research in older adults with neurocognitive disorders, we investigated the consistency of sleep data recorded from a wrist-worn activity monitor in this population.

Methods

Fitbit® activity monitors were worn by hospitalized older adults as part of a parent study investigating sleep and step count in patients recovering from hip fracture surgery in a tertiary care academic hospital in Hamilton, Canada between March 2018 and June 2019. In this secondary analysis, we compared the proportion of missing sleep data between participants with and without a neurocognitive disorder and used a multivariable model to assess the association between neurocognitive disorder and missing sleep data.

Results

Of 67 participants included in the analysis, 22 had a neurocognitive disorder (median age: 86.5 years). Sleep data were missing for 47% of the neurocognitive disorder group and 23% of the non-neurocognitive disorder group. The presence of a neurocognitive disorder was associated with an increased likelihood of missing sleep data using the Fitbit® activity monitors (adjusted odds ratio: 3.41; 95% confidence interval: 1.06-11.73, p = 0.04).

Conclusion

The inconsistent nature of sleep data tracking in hospitalized older adults with neurocognitive disorders highlights the challenges of using interventions in patient populations who are often excluded from validation studies. As opportunities expand for activity monitoring in persons with neurocognitive disorders, novel technologies not previously studied in this group should be used with caution.

Going Silent: Redesigning the Activation Process for In-Hospital Cardiopulmonary Arrests

INTRODUCTION

Reducing environmental noise has become a priority for many health systems. Following a 10-week preparation period, our health system transitioned from an overhead-activated to a silently activated in-hospital code team notification system. The goal of this initiative was to reduce environmental noise and support code team communication and function without adversely affecting response time, provider availability, or key quality metrics.

METHODS

Transitioning from overhead to silently activated events involved a three-step quality improvement approach. Input from key stakeholders and preimplementation education were of key importance. Multiple timed trials and a full in situ simulation were completed before going live with the new process.

RESULTS

Evaluation of 6-month pre- and postimplementation quality metrics showed no significant difference in compliance with defibrillating shockable rhythms within two minutes, event survival, or survival to discharge. Provider survey data and Hospital Consumer Assessment of Healthcare Providers and Systems "quiet at night" scores were not significantly different.

CONCLUSION

By utilizing a multistep implementation approach, transitioning from overhead pages to a silently activated system for in-hospital code team activation was feasible and safe. Abandoning the overhead paging system did not lead to a decrease in key quality metrics nor impair team perception of code function.

The prevalence and impact of pre-existing sleep disorder diagnoses and objective sleep parameters in patients hospitalized for COVID-19

STUDY OBJECTIVES

Obstructive sleep apnea and other sleep disorders overlap with comorbidities associated with poor outcomes related to severe acute respiratory syndrome coronavirus 2 infection. However, the prevalence of obstructive sleep apnea among patients hospitalized for COVID-19 and relationship to outcomes is poorly characterized, and the relevance of other sleep disorders remains unknown. The objective of this study was to identify the prevalence of pre-existing sleep disorders and association with outcomes related to severe COVID-19 illness.

METHODS

Patients with severe acute respiratory syndrome coronavirus 2 infection admitted to the University of Michigan Hospital System were included. Electronic medical records were queried for sleep disorders diagnostic codes. Data were extracted from polysomnography and home sleep testing in a subgroup with previous diagnostic testing at our center. Logistic regression was used to examine the association of sleep disorders with mechanical ventilation requirement, treatment with vasopressors, and death and Cox proportional hazards regression for time to discharge.

RESULTS

Among n = 572 adult patients hospitalized for COVID-19, 113 (19.8%) patients had obstructive sleep apnea, 4 patients had central sleep apnea (0.7%), 5 had hypoventilation (0.9%), 63 had insomnia (11.0%), and 22 had restless legs syndrome or periodic limb movements disorder (3.9%). After adjusting for age, sex, body mass index, and race, no significant relationship was apparent between sleep disorders diagnoses or indices of sleep-disordered breathing severity and outcomes.

CONCLUSIONS

This is the first study to determine the prevalence of obstructive sleep apnea and other sleep disorders in a well-characterized cohort of patients hospitalized for COVID-19. Once hospitalized, a significant contribution of sleep disorders to outcomes was not identified. Therefore, future evaluations should focus on earlier outcomes, such as infection or clinical manifestations after exposure to severe acute respiratory syndrome coronavirus 2.

Sleep Deprivation in the Intensive Care Patient

TOPIC

Sleep deprivation in the intensive care unit setting.

CLINICAL RELEVANCE

The Society of Critical Care Medicine has identified sleep deprivation as a significant contributor to the development of delirium in adult patients in the intensive care unit. Thus, preventing and managing sleep deprivation is important in reducing the incidence of delirium in this patient population. A multifaceted and multidisciplinary approach to promoting sleep in the intensive care unit setting that includes sleep hygiene routines, nursing care plans, and appropriate medication regimens may improve patient outcomes, including reducing delirium.

PURPOSE OF ARTICLE

To review the current literature on sleep deprivation in the intensive care unit setting and present care guidelines in a concise format. This information may be helpful in the development of clinical tools and may guide future quality improvement projects aimed at reducing delirium through sleep promotion in critical care patients.

CONTENT COVERED

A review of current literature and national organization recommendations revealed consistent themes in addressing the problem of sleep deprivation in the intensive care unit. Modifiable and nonmodifiable risk factors included frequent care interactions, light, noise, medication effects, and preexisting sleep problems.

Evaluating Pain, Opioids, and Delirium in Critically Ill Older Adults

Untreated pain and pain management with opioids are independent precipitating factors for delirium. This retrospective study evaluated the relationships among pain severity, its management with opioids, and the onset of delirium in older adult patients admitted to the surgical intensive care unit (SICU). Consecutive patients aged 65 or greater admitted to the SICU over a 5-month period were examined (n = 172). When assessed using a multivariable general estimating equation model, opioids (chi-square [χ²], 12.34, p = .0004), but not pain (χ², 3.31, p = .0688) were significant in predicting next-day delirium status. Controlling for pain, patients exposed to opioids were 2.5 times more likely to develop delirium than patients not exposed (95% Confidence Interval: 1.44-4.36). Our data shows that opioid administration predicted the onset of next-day delirium. In an effort to prevent delirium, future research should focus on opioid-sparing pain management approaches to mitigate pain and delirium.

Role and Therapeutic Potential of Melatonin in the Central Nervous System and Cancers

Melatonin (MLT) is a powerful chronobiotic hormone that controls a multitude of circadian rhythms at several levels and, in recent times, has garnered considerable attention both from academia and industry. In several studies, MLT has been discussed as a potent neuroprotectant, anti-apoptotic, anti-inflammatory, and antioxidative agent with no serious undesired side effects. These characteristics raise hopes that it could be used in humans for central nervous system (CNS)-related disorders. MLT is mainly secreted in the mammalian pineal gland during the dark phase, and it is associated with circadian rhythms. However, the production of MLT is not only restricted to the pineal gland; it also occurs in the retina, Harderian glands, gut, ovary, testes, bone marrow, and lens. Although most studies are limited to investigating the role of MLT in the CNS and related disorders, we explored a considerable amount of the existing literature. The objectives of this comprehensive review were to evaluate the impact of MLT on the CNS from the published literature, specifically to address the biological functions and potential mechanism of action of MLT in the CNS. We document the effectiveness of MLT in various animal models of brain injury and its curative effects in humans. Furthermore, this review discusses the synthesis, biology, function, and role of MLT in brain damage, and as a neuroprotective, antioxidative, anti-inflammatory, and anticancer agent through a collection of experimental evidence. Finally, it focuses on the effect of MLT on several neurological diseases, particularly CNS-related injuries.

Study protocol for a prospective randomised double-blind placebo-controlled clinical trial investigating a Better Outcome with Melatonin compared to Placebo Administered to normalize sleep-wake cycle and treat hypoactive ICU Delirium: the Basel BOMP-AID study

INTRODUCTION

Delirium is frequently observed in the intensive care unit (ICU) population, in particular. Until today, there is no evidence for any reliable pharmacological intervention to treat delirium. The Basel BOMP-AID (Better Outcome with Melatonin compared to Placebo Administered to normalize sleep-wake cycle and treat hypoactive ICU Delirium) randomised trial targets improvement of hypoactive delirium therapy in critically ill patients and will be conducted as a counterpart to the Basel ProDex Study (Study Protocol, BMJ Open, July 2017) on hyperactive and mixed delirium. The aim of the BOMP-AID trial is to assess the superiority of melatonin to placebo for the treatment of hypoactive delirium in the ICU. The study hypothesis is based on the assumption that melatonin administered at night restores a normal circadian rhythm, and that restoration of a normal circadian rhythm will cure delirium.

METHODS AND ANALYSIS

The Basel BOMP-AID study is an investigator-initiated, single-centre, randomised controlled clinical trial for the treatment of hypoactive delirium with the once daily oral administration of melatonin 4 mg versus placebo in 190 critically ill patients. The primary outcome measure is delirium duration in 8-hour shifts. Secondary outcome measures include delirium-free days and death at 28 days after study inclusion, number of ventilator days, length of ICU and hospital stay, and sleep quality. Patients will be followed after 3 and 12 months for activities of daily living and mortality assessment. Sample size was calculated to demonstrate superiority of melatonin compared with placebo regarding the duration of delirium. Results will be presented using an intention-to-treat approach.

ETHICS AND DISSEMINATION

This study has been approved by the Ethics Committee of Northwestern and Central Switzerland and will be conducted in compliance with the protocol, the current version of the Declaration of Helsinki, the International Conference on Harmonisation (ICH) of technical requirements for registration of pharmaceuticals for human use; Good Clinical Practice (GCP) or ISO EN 14155 (as far as applicable), as well as all national legal and regulatory requirements. Study results will be presented in international conferences and published in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT03438526.

PROTOCOL VERSION

Clinical Study Protocol Version 3, 10.03.2019.

Results from a double blinded, randomised, placebo-controlled, feasibility trial of melatonin for the treatment of delirium in older medical inpatients

BACKGROUND

Delirium is common in elderly inpatients, causing distress, cognitive decline and death. No known intervention improves the course of delirium; current treatments are symptomatic, and limited by lack of efficacy and adverse effects. There is an urgent need to find an effective treatment for delirium.

AIMS

To determine the feasibility of a trial of oral melatonin 5 mg nightly for five nights for the treatment of delirium in older medical inpatients, and determine the participants required to demonstrate a clinically and statistically significant decrease in severity of delirium in older medical inpatients treated with melatonin.

METHODS

This was a double blinded, randomised controlled trial in general internal medicine units of a tertiary teaching hospital. Older (≥70 years) inpatients with confusion assessment method positive hyperactive or mixed delirium were suitable for inclusion. Subjects received melatonin 5 mg oral nightly for five nights or matching placebo. The primary outcome was the Memorial Delirium Assessment Scale (MDAS) administered daily.

RESULTS

No adverse effects occurred due to melatonin. In the treatment group, the mean change in MDAS from baseline during treatment period was 2.5 ± 5.0 points, in the placebo group, 2.1 ± 4.1 points, a non-significant difference. A power calculation accounting for drop-out (31.0%), suggests 120 participants would be required to demonstrate with 90% power that melatonin 5 mg reduces the severity of delirium by 3 points or more on MDAS.

CONCLUSIONS

A trial of the hypothesis that 5 mg melatonin nightly for five nights reduces delirium severity in older medical inpatients would require 120 patients, and is feasible.

Early Postoperative Actigraphy Poorly Predicts Hypoactive Delirium

STUDY OBJECTIVES

Delirium is a postoperative complication accompanied by disturbances in attention, cognition, arousal, and psychomotor activity. Wrist actigraphy has been advocated to study inactivity and inferred sleep patterns during delirium. We hypothesized that altered patterns of motor activity or immobility, reflective of disordered sleep and wakefulness patterns, would serve as predictive markers of hypoactive postoperative delirium.

METHODS

Eighty-four elderly surgical patients were classified into three groups based on the timing of hypoactive delirium following surgery: intact with no delirium throughout postoperative days (POD) 0-5 (n = 51), delirium during POD 0-1 (n = 24), and delirium during POD 2-5 (n = 13). Delirium was detected on daily Confusion Assessment Method evaluations and chart review. Actigraphy measures were calculated from accelerometry signals acquired on the first postoperative day (POD 0, 16:00-23:00) and night (POD 0, 23:00-POD 1, 06:00).

RESULTS

Actigraphy metrics showed substantial interpatient variability. Among the three patient groups, only those without delirium showed greater movement during the day compared to night and also fewer minutes of night immobility (P = .03 and P = .02, Wilcoxon rank-sum tests). These patients were poorly discriminated from those with delirium during either POD 0-1 or POD 2-5, using differences in day and night activity (C-statistic, 95% confidence interval [CI]: 0.66 [0.53-0.79] and C-statistic, 95% CI: 0.71 [0.55-0.87], respectively). Inclusion of low-frequency signals improved performance of immobility measures without affecting those based on activity. Cognitively intact patients during POD 0-5 were distinguished from those with delirium during POD 0-1, based on differences in the number of day and night immobile minutes (C-statistic 0.65, 95% CI: [0.53-0.78]). Actigraphy metrics with the strongest association to delirium incidence were not reliably correlated with an increased risk during POD 0-5, when accounting for patient age, sex, intensive care unit admission, and Charlson Comorbidity Index (adjusted odds ratio of 1.7, 95% CI: [1.0-3.0], P = .09, likelihood ratio test).

CONCLUSIONS

Early postoperative wrist actigraphy metrics that serve as markers of sleep and wakefulness offer limited capacity as sole predictors or markers of hypoactive delirium.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Title: Electroencephalography Guidance of Anesthesia to Alleviate Geriatric Syndromes (ENGAGES) Study; Identifier: NCT02241655; URL: https://clinicaltrials.gov/ct2/show/NCT02241655.

Melatonin as a Hormone: New Physiological and Clinical Insights

Melatonin is a ubiquitous molecule present in almost every live being from bacteria to humans. In vertebrates, besides being produced in peripheral tissues and acting as an autocrine and paracrine signal, melatonin is centrally synthetized by a neuroendocrine organ, the pineal gland. Independently of the considered species, pineal hormone melatonin is always produced during the night and its production and secretory episode duration are directly dependent on the length of the night. As its production is tightly linked to the light/dark cycle, melatonin main hormonal systemic integrative action is to coordinate behavioral and physiological adaptations to the environmental geophysical day and season. The circadian signal is dependent on its daily production regularity, on the contrast between day and night concentrations, and on specially developed ways of action. During its daily secretory episode, melatonin coordinates the night adaptive physiology through immediate effects and primes the day adaptive responses through prospective effects that will only appear at daytime, when melatonin is absent. Similarly, the annual history of the daily melatonin secretory episode duration primes the central nervous/endocrine system to the seasons to come. Remarkably, maternal melatonin programs the fetuses' behavior and physiology to cope with the environmental light/dark cycle and season after birth. These unique ways of action turn melatonin into a biological time-domain-acting molecule. The present review focuses on the above considerations, proposes a putative classification of clinical melatonin dysfunctions, and discusses general guidelines to the therapeutic use of melatonin.

Evaluating the use of dexmedetomidine for the reduction of delirium: An integrative review

Delirium, an acute change in cognition and attention not secondary to a pre-existing condition or dementia, affects nearly 40,000 hospitalized older adults in the United States every day. Delirium is associated with increased healthcare costs of $16,303 to $64,421 per patient. To date, no single pharmacological intervention is effective in preventing or treating delirium in critically ill patients. Evidence suggests the alpha-2 agonist, dexmedetomidine, may reduce or prevent delirium. An integrative review examined whether dexmedetomidine was associated with a lower incidence of delirium compared to other analgesic and sedation strategies. PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guided this review and 16 publications met quality criteria for inclusion. These studies support that postoperative administration of dexmedetomidine may reduce delirium in patients, particularly following cardiac surgery. Further research is needed to determine the benefits of dexmedetomidine in patients on mechanical ventilation and optimal timing and duration of administration.

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.