Effect of melatonin on incidence of delirium among patients with hip fracture: a multicentre, double-blind randomized controlled trial

Characteristics associated with effectiveness in postoperative delirium research: a systematic review of randomised controlled trials with meta-regression and meta-analysis

BACKGROUND

Postoperative delirium remains prevalent despite extensive research through randomised trials aimed at reducing its incidence. Understanding trial characteristics associated with interventions' effectiveness facilitates data interpretation.

METHODS

Trial characteristics were extracted from eligible trials identified through two systematic literature searches. Multivariable meta-regression was used to investigate trial characteristics associated with effectiveness estimated using odds ratios. Meta-analysis was used to investigate pooled effectiveness.

RESULTS

We identified 201 eligible trials. Compared with China, trials from the USA/Canada (ratio of odds ratio, 1.89; 95% confidence interval, 1.45-2.45) and Europe/Australia/New Zealand (1.67; 1.29-2.18) had an 89% and 67% higher odds ratio, respectively, suggesting reduced effectiveness. The effectiveness was enhanced when the incidence of postoperative delirium increased (0.85; 0.79-0.92, per 10% increase). Trials with concerns related to deviations from intended interventions reported increased effectiveness compared with those at low risk (0.69; 0.53-0.90). Compared with usual care, certain interventions appeared to have reduced the incidence of postoperative delirium in low-risk trials with low-to-moderate certainty of evidence. However, these findings should be considered inconclusive because of challenges in grouping heterogeneous interventions, the limited number of eligible trials, the prevalence of small-scale studies, and potential publication bias.

CONCLUSIONS

The effectiveness of postoperative delirium trials varied based on the region of trial origin, the incidence of delirium, and the risk of bias. The limitations caution against drawing definitive conclusions from different bodies of evidence. These findings highlight the imperative need to improve the quality of research on a global scale.

SYSTEMATIC REVIEW PROTOCOL

PROSPERO (CRD42023413984).

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.

The impact of melatonin on postoperative delirium in geriatric patients after colorectal surgery: a randomized placebo-controlled trial

BACKGROUND

The current study was designed to evaluate the role of prophylactic melatonin administration in reducing delirium occurrence in elderly patients undergoing colorectal cancer surgeries.

METHODS

One hundred patients of both genders undergoing elective colorectal cancer surgeries under general anesthesia were randomly allocated into two equal groups. A treatment group of patients (Melatonin group) received five mg of melatonin the night before surgery, twelve hours before the scheduled surgery time, and an additional five mg of melatonin two hours before surgery. The control group of patients received placebo tablets at the same time points. Delirium score, sedation score, pain score, hemodynamics, oxygen saturation, and blood requirements were recorded.

RESULTS

Twenty-eight patients (56%) in the control group versus 18 (36%) in the melatonin group developed delirium (P=0.045), OR=2.26, 95% CI: 1.013-5.05. Five patients (18%) in the control group versus six (33%) ‎in the melatonin group developed delirium on discharge from the ‎recovery room (P=0.749), OR=1.22, 95% CI: 0.34-4.31, while 23 patients (82%) in the control group versus ‎‎12 (66%) in the melatonin group developed delirium six hours postoperative (P=0.021), OR=1.705, 95% CI: 1.02-2.81 ‎with higher nursing delirium screening score in the control group 2 (1, 4) versus 1 (0, 2) in the melatonin group (P=0.002), 95% CI: 1.77-2.71.

CONCLUSIONS

The prophylactic administration of melatonin may decrease the incidence of postoperative delirium in elderly patients undergoing colorectal surgeries under general anesthesia.

The effectiveness of preoperative delirium prevention in intermediate to high-risk older surgical patients: A systematic review

BACKGROUND

Few reviews have addressed delirium prevention among intermediate to high-risk older surgical patients.

AIMS

To map preoperative delirium prevention interventions for older surgical patients at intermediate to high risk of developing delirium, assess outcomes and identify gaps in knowledge.

DESIGN

Systematic narrative review of randomised controlled trials reported following the PRISMA checklist.

METHODS

A systematic search was conducted of the literature published from 1990 to October 2022 in Medline, CINAHL and Ageline and of the grey literature in Google Scholar. Randomised controlled trials were retrieved that assessed the effectiveness of preoperative delirium prevention interventions for older surgical patients at intermediate to high risk of delirium. Data were extracted using a data extraction tool, and results were tabulated. Studies were assessed for bias using the Cochrane Collaboration Risk of Bias tool.

RESULTS

Twenty-one studies met the selection criteria including N = 5096 participants. Two studies tested cognitive training, two studies tested fascia iliaca compartment block and one study assessed femoral nerve block. Ten studies tested prophylactic medications including methylprednisolone. Five studies investigated geriatric assessment and management. One study assessed transcutaneous electrical acupoint stimulation. In the two studies testing fascia iliaca compartment block, there was a reduction in postoperative delirium for orthopaedic patients. Methylprednisolone reduced postoperative delirium in orthopaedic patients and in those undergoing gastrointestinal surgery. Results of all other interventions on the occurrence of postoperative delirium and additional outcomes including the severity and duration of delirium were inconclusive.

CONCLUSIONS

Despite the promising results for fascia iliaca compartment block and methylprednisolone, there is limited knowledge regarding evidence-based delirium prevention interventions. Most studies had small sample sizes indicating that the current evidence is exploratory. There is an urgent need for the funding and conduct of trials to test preventative interventions for older surgical patients at intermediate to high risk of developing delirium.

Efficacy and safety of perioperative melatonin for postoperative delirium in patients undergoing surgery: a systematic review and meta-analysis

OBJECTIVE

To assess the efficacy and safety of perioperative melatonin and melatonin agonists in preventing postoperative delirium (POD).

METHODS

We conducted a systematic search for randomized controlled trials (RCTs) published through December 2022. The primary outcome was efficacy based on the incidence of POD (POD-I). Secondary outcomes included efficacy and safety according to the length of hospital or intensive care unit stay, in-hospital mortality, and adverse events. Subgroup analyses of POD-I were based on the type and dose of drug (low- and high-dose melatonin, ramelteon), the postoperative period (early or late), and the type of surgery.

RESULTS

In the analysis (16 RCTs, 1981 patients), POD-I was lower in the treatment group than in the control group (risk ratio [RR] = 0.57). POD-I was lower in the high-dose melatonin group than in the control group (RR = 0.41), whereas no benefit was observed in the low-dose melatonin and ramelteon groups. POD-I was lower in the melatonin group in the early postoperative period (RR = 0.35) and in patients undergoing cardiopulmonary surgery (RR = 0.54).

CONCLUSION

Perioperative melatonin or melatonin agonist treatment suppressed POD without severe adverse events, particularly at higher doses, during the early postoperative period, and after cardiopulmonary surgery.

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.

The Efficacy of Ramelteon to Prevent Postoperative Delirium After General Anesthesia in the Elderly: A Double-Blind, Randomized, Placebo-Controlled Trial

OBJECTIVE

Postoperative delirium is common and serious in elderly patients. Several drugs have been proposed as potential prophylactic agents for postoperative delirium. Studies on melatonin receptor agonists showed heterogeneity in age, cognitive function, anesthesia, surgery, interventions, methodologies for assessing outcomes, and results. Our objective was to examine the effect of ramelteon to prevent postoperative delirium in elderly patients, including those with dementia.

DESIGN

A stratified, double-blind, randomized, placebo-controlled trial (UMIN000028436, jRCTs031180054).

SETTING

Tertiary medical center.

PARTICIPANTS

Patients aged older than or equal to 65 years undergoing elective surgery under general anesthesia.

INTERVENTION

Ramelteon (8 mg orally) or placebo (lactose) for six nights (the preoperative night and five consecutive nights from postoperative day 1 to 5) at around 9 P.M.

MEASUREMENTS

Patients were screened for postoperative delirium using the Confusion Assessment Method for the Intensive Care Unit twice daily until the sixth postoperative day. Patients with positive results were referred to a consultant psychiatrist to establish the diagnosis of delirium.

RESULTS

A total of 108 patients were randomly assigned to receive ramelteon (n = 55) or placebo (n = 53). Most of the patients' characteristics were reasonably well-balanced between the two groups. The stratified log-rank test showed no significant difference in preventing postoperative delirium between ramelteon and placebo (χ2 = 0.30, degrees of freedom = 1, p = 0.60). The Cox proportional hazard ratio for ramelteon compared to placebo was 1.40 (95% confidence interval: 0.40-4.85, χ2 for likelihood ratio test = 0.29, degrees of freedom = 1, p = 0.60).

CONCLUSION

There was no significant difference in the incidence of postoperative delirium between ramelteon and placebo after general anesthesia in elderly patients.

Efficacy and moderators of prevention and treatment of delirium with melatonin receptor agonists: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

Delirium is a complex and heterogeneous condition that significantly affects patient outcome. This study aimed to conduct a systematic review and meta-analysis to investigate the effects of melatonin and melatonin receptor agonists (MRAs) on delirium prevention and treatment.

METHOD

Randomized controlled studies, using MRAs as an intervention and placebo as a control were included. We conducted meta-analyses with random-effects model and trial sequential analysis.

RESULTS

A total of 33 studies involving 4850 participants were included. The meta-analysis revealed a significant preventive effect of MRAs on delirium (risk ratio = 0.65, p < 0.01), while no significant therapeutic effect was observed. Additionally, MRAs were associated with a significant reduction in mortality rate (risk ratio = 0.90, p = 0.02) in delirium prevention studies. Furthermore, subgroup analyses revealed that assessment scales and the frequency of delirium detection may be significant moderators of the delirium-preventive efficacy of MRAs.

CONCLUSION

This study provides evidence of the potential effects of MRAs in preventing delirium and reducing mortality. Further research is required to elucidate the therapeutic potential of MRAs for delirium and identify specific patient populations that may benefit from this agent.

Prophylactic effect of exogenous melatonin and melatonin receptor agonists on postoperative delirium in elderly patients: a systemic review and meta-analysis of randomized controlled trials

BACKGROUND

The prophylactic effect of exogenous melatonin and melatonin receptor agonists (MMRAs) on postoperative delirium (POD) in elderly patients remains controversial.

OBJECTIVE

This study aimed to assess the prophylactic effect of MMRAs on POD by conducting a systemic review and meta-analysis of randomized controlled trials (RCTs).

METHODS

We systematically searched four electronic databases including PubMed, Web of Science, Cochrane Library, and Embase for the eligible studies up to February 28, 2023. The Cochrane risk of bias tool was used for assessing the risk of bias in the included RCTs. The occurrence of POD was the primary outcome. The quality of evidence was evaluated by Grading of Recommendations Assessment, Development, and Evaluation.

RESULTS

A total of 11 RCTs comprising patients (MMRA group: 777 patients and placebo group: 781 patients) were included. The results of the meta-analysis showed that the MMRA group had a lower occurrence of POD than the placebo group (risk ratio = 0.70, 95% confidence interval: 0.51-0.97, P < 0.05, I2 = 59%). The subgroup analysis showed that melatonin significantly reduced the occurrence of POD (moderate-quality evidence), whereas ramelteon and tryptophan had no significant impact (moderate-quality evidence).

CONCLUSION

Existing evidence suggested that perioperative use of melatonin can prevent POD in elderly patients.

Preventing and treating delirium in clinical settings for older adults

Delirium is a serious consequence of many acute or worsening chronic medical conditions, a side effect of medications, and a precipitant of worsening functional and cognitive status in older adults. It is a syndrome characterized by fluctuations in cognition and impaired attention that develops over a short period of time in response to an underlying medical condition, a substance (prescribed, over the counter, or recreational), or substance withdrawal and can be multi-factorial. We present a narrative review of the literature on nonpharmacologic and pharmacologic approaches to prevention and treatment of delirium with a focus on older adults as a vulnerable population. Older adult patients are most at risk due to decreasing physiologic reserves, with delirium rates of up to 80% in critical care settings. Presentation of delirium can be hyperactive, hypoactive, or mixed, making identification and study challenging as patients with hypoactive delirium are less likely to come to attention in an inpatient or long-term care setting. Studies of delirium focus on prevention and treatment with nonpharmacological or medication interventions, with the preponderance of evidence favoring multi-component nonpharmacological approaches to prevention as the most effective. Though use of antipsychotic medication in delirium is common, existing evidence does not support routine use, showing no clear benefit in clinically significant outcome measures and with evidence of harm in some studies. We therefore suggest that antipsychotics be used to treat agitation, psychosis, and distress associated with delirium at the lowest effective doses and shortest possible duration and not be considered a treatment of delirium itself. Future studies may clarify the use of other agents, such as melatonin and melatonin receptor agonists, alpha-2 receptor agonists, and anti-epileptics.

Melatonin intervention to prevent delirium in the intensive care units: a systematic review and meta-analysis of randomized controlled trials

Objective

To determine the preventive effect of melatonin on delirium in the intensive care units.

Methods

We conducted a systematic search of the PubMed, Cochrane Library, Science, Embase, and CNKI databases, with retrieval dates ranging from the databases' inception to September 2022. Controlled trials on melatonin and placebo for preventing delirium in the intensive care units were included. The meta-analysis was performed using Review Manager software (version 5.3) and Stata software (version 14.0).

Results

Six studies involving 2374 patients were included in the meta-analysis. The results of the meta-analysis showed that melatonin did not reduce the incidence of delirium in ICU patients (odds ratio [OR]: 0.71; 95% confidence interval [CI]: 0.46 to 1.12; p = 0.14). There was a strong hetero-geneity between the selected studies (I2 = 74%). Subgroup analysis results showed that melatonin reduced the incidence of delirium in cardiovascular care unit (CCU) patients (OR: 0.52; 95% CI: 0.37 to 0.73; p=0.0001), but did not in general intensive care unit (GICU) patients (OR: 1.14; 95% CI: 0.86 to 1.50; p=0.35). In terms of the secondary outcomes, there were no significant differences in all-cause mortality (OR: 0.85; 95% CI: 0.66 to 1.09; p=0.20), length of ICU stay (mean difference [MD]: 0.33; 95% CI: -0.53 to 1.18; p=0.45), or length of hospital stay (MD: 0.51; 95% CI: -1.17 to 2.19; p=0.55).

Conclusion

Melatonin reduced the incidence of delirium in CCU patients, but did not significantly reduce the incidence of delirium in GICU patients.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42022367665.

Comment on Yang et al., 2020: Melatonergic agents in the prevention of delirium: A network meta-analysis of randomized controlled trials

An analysis of delirium prevention considering only older adults is essential. Delirium markedly impacts the older adult population, as it is associated with inpatient occurrence rates from 14% to 56% and hospital mortality rates from 25% to 33% [2]. Ageing comes with a cumulative decline in physiological systems and is a relevant risk factor for chronic diseases [3,4]. Delirium causes in older adults can be multifactorial, including underlying medical conditions, medications, and environmental factors. Therefore, it is vital for healthcare providers to monitor for delirium symptoms in older adults and to implement appropriate interventions, such as addressing underlying medical conditions and addressing possible triggers [5]. Likewise, it is reasonable to think that eventual delirium preventive solutions for older patients would differentiate from the general population.

Preoperative Risk Factors Associated with Increased Incidence of Postoperative Delirium: Systematic Review of Qualified Clinical Studies

Postoperative delirium (POD) is an acute alteration of mental state, characterized by reduced awareness and attention, occurring up to five postoperative days after recovery from anesthesia. Several original studies and reviews have identified possible perioperative POD risk factors; however, there is no comprehensive review of the preoperative risk factors in patients diagnosed with POD using only validated diagnostic scales. The aim of this systematic review was to report the preoperative risk factors associated with an increased incidence of POD in patients undergoing non-cardiac and non-brain surgery. The reviewed studies included original research papers that used at least one validated diagnostic scale to identify POD occurrence for more than 24 h. A total of 6475 references were retrieved from the database search, with only 260 of them being suitable for further review. Out of the 260 reviewed studies, only 165 that used a validated POD scale reported one or more preoperative risk factors. Forty-one risk factors were identified, with various levels of statistical significance. The extracted risk factors could serve as a preoperative POD risk assessment workup. Future studies dedicated to the further evaluation of the specific preoperative risk factors' contributions to POD could help with the development of a weighted screening tool.

[Delirium in the context of intensive care medicine-Part 2: diagnosis, prevention and treatment]

Despite the high prevalence and the enormous medical and health economic impact, delirium syndromes are often underdiagnosed, which is mainly attributable to the high frequency of hypoactive delirium and to the frequently subtle and fluctuating psychopathology in the initial phase of delirium. These aspects also justify the need for a consequent and continuous application of standardized screening tools to detect delirium as early as possible. A multidimensional, nonpharmacological prevention of delirium is effective and still underutilized in the clinical practice. So far, there are no consensus recommendations regarding the pharmacological prevention of delirium. From a therapeutic perspective a causal approach is prioritized. Pharmacological treatment of delirium can only be considered under strict observance of specific indicators. When treating non-withdrawal-related delirium benzodiazepines should be avoided.

Melatonin or Ramelteon for Delirium Prevention in the Intensive Care Unit: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Melatonin modulates the circadian rhythm and has been studied as a preventive measure against the development of delirium in hospitalized patients. Such an effect may be more evident in patients admitted to the ICU, but findings from the literature are conflicting. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs). We assessed whether melatonin or ramelteon (melatonin agonist) reduce delirium incidence as compared to a placebo in ICU patients. Secondary outcomes were ICU length of stay, duration of mechanical ventilation (MV) and mortality. Estimates are presented as risk ratio (RR) or mean differences (MD) with 95% confidence interval (CI). Nine RCTs were included, six of them reporting delirium incidence. Neither melatonin nor ramelteon reduced delirium incidence (RR 0.76 (0.54, 1.07), p = 0.12; I² = 64%), although a sensitivity analysis conducted adding other four studies showed a reduction in the risk of delirium (RR = 0.67 (95%CI 0.48, 0.92), p = 0.01; I² = 67). Among the secondary outcomes, we found a trend towards a reduction in the duration of MV (MD -2.80 (-6.06, 0.47), p = 0.09; I² = 94%) but no differences in ICU-LOS (MD -0.26 (95%CI -0.89, 0.37), p = 0.42; I² = 75%) and mortality (RR = 0.85 (95%CI 0.63, 1.15), p = 0.30; I² = 0%). Melatonin and ramelteon do not seem to reduce delirium incidence in ICU patients but evidence is weak. More studies are needed to confirm this finding.

Amelioratory Effect of Melatonin on Cognition Dysfunction Induced by Sevoflurane Anesthesia in Aged Mice

Background

Postoperative cognitive dysfunction (POCD) can be described as a clinical phenomenon characterized by cognitive impairment in patients, particularly elderly patients, after anesthesia and surgery. Researchers have focused on the probable effect of general anesthesia drugs on cognitive functioning status in older adults. Melatonin is an indole-type neuroendocrine hormone with broad biological activity and potent anti-inflammatory, anti-apoptotic, and neuroprotective effects. This study investigated the effects of melatonin on cognitive behavior in aged mice anesthetized with sevoflurane. In addition, melatonin's molecular mechanism was determined.

Objectives

This study aimed to investigate the mechanisms of melatonin against sevoflurane-induced neurotoxicity.

Methods

A total of 94 aged C57BL/6J mice were categorized into different groups, namely control (control + melatonin (10 mg/kg)), sevoflurane (sevoflurane + melatonin (10 mg/kg)), sevoflurane + melatonin (10 mg/kg) + phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) inhibitor LY294002 (30 mg/kg), and sevoflurane + melatonin (10 mg/kg) + mammalian target of rapamycin (mTOR) inhibitor (10 mg/kg). The open field and Morris water maze tests were utilized to assess the neuroprotective effects of melatonin on sevoflurane-induced cognitive impairment in aged mice. The expression levels of the apoptosis-linked proteins, PI3K/Akt/mTOR signaling pathway, and pro-inflammatory cytokines in the brain's hippocampus region were determined using the Western blotting technique. The apoptosis of the hippocampal neurons was observed using the hematoxylin and eosin staining technique.

Results

Neurological deficits in aged, sevoflurane-exposed mice were significantly decreased after melatonin treatment. Mechanistically, melatonin treatment restored sevoflurane-induced down-regulated PI3K/Akt/mTOR expression and significantly attenuated sevoflurane-induced apoptotic cells and neuroinflammation.

Conclusions

The findings of this study have highlighted the neuroprotective effect of melatonin on sevoflurane-induced cognitive impairment via regulating the PI3K/Akt/mTOR pathway, which might be effective in the clinical treatment of elderly patients with anesthesia-induced POCD.

Is There a Role for Medication in Managing Delirium with Dementia?

People with dementia are more likely to develop delirium. We conducted a brief literature search and give a pragmatic overview of the key issues. Making rational and safe prescribing decisions is highly influenced by organisational culture and embedded staff practices. Comprehensive assessment for unmet physical, psychological, and social needs is an important intervention in itself. Taking a broad overview of possible pharmacological interventions should include stopping inappropriate medications and prescribing for key drivers of the underlying causes of delirium. Prescribing psychotropic medications may be indicated where there is significant distress or risk to the person with dementia and risk to those around them. It is vital to consider the dementia subtype and, where possible, involve family and friend carers in the decision-making process. Medications should be prescribed at the lowest possible dose for the least amount of time after carefully weighing risks versus benefits and documenting these. While these cases are challenging for staff and families, it can be rewarding to improve the quality of life and lessen distress for the person with dementia. There are also opportunities for informing family and friend carers, educating the wider multidisciplinary team, and promoting organisational change.

[Chronobiological interventions for prevention and treatment of delirium in critically ill patients]

Circadian body and behavior rhythms serve to coordinate and maintain the physiological processes in the human body. A disruption of these rhythms frequently occurs in intensive care patients and can be the cause for the development of delirium. This review article discusses the underlying pathophysiological mechanisms and develops a chronobiologically oriented prevention and treatment approach for delirium in the context of intensive care medicine.

Melatonin intervention to prevent delirium in hospitalized patients: A meta-analysis

BACKGROUND

Evaluation of the effectiveness of melatonin is necessary to prevent the development of delirium in hospitalized patients. Melatonin (N-acetyl-5-methoxytryptamine) is a hormone produced by the pineal gland of the brain from the amino acid tryptophan. Synthetic melatonin supplements have been used for various medical conditions, especially sleep-related diseases, and have proved to be successful.

AIM

To determine the effect of melatonin on the prevention of delirium in hospitalized patients.

METHODS

A literature search of the CNKI, Wanfang Database, VIP Database, China Biomedical Literature Database, PubMed, Embase, Cochrane Library, Web of Science, and other databases was conducted. The CNKI, Wanfang Database, VIP Database (VIP), and China Biomedical Literature Database were searched for Chinese studies, and PubMed, Embase, Cochrane Library, Web of Science and other databases were searched for international studies. It will be established in June 2021 in a randomized controlled trial (RCT) whether melatonin treatment for 6 mo prevents delirium in hospitalized patients. Literature screening, quality review, and data extraction were carried out using the Cochrane Manual 5.1.0 systematic evaluation method, and Stata 15.0 software and Review Manager 5.3 were used for meta-analysis and processing.

RESULTS

A total of 18 new RCT articles and 18 experimental subjects were identified. The results of the meta-analysis showed that following the occurrence of delirium, melatonin reduced the incidence of delirium in patients (RR = 0.69, 95%CI: 0.60-0.80), which is of significance, but heterogeneity was significant I² = 62%. Subgroup analysis was performed to examine the source of heterogeneity, and it was found that different patient types were the source of heterogeneity; the research on subgroup analysis was of high quality and homogeneous. To determine the reliability and robustness of the research results, a sensitivity analysis was carried out. The results showed that after excluding individual studies one by one, the effect size was still within 95%CI, which strengthened the reliability of the original meta-analysis results. Melatonin has a significant preventive effect on delirium in hospitalized medical patients [RR = 0.60, 95%CI: 0.47-0.76), P < 0.001].

CONCLUSION

Melatonin can reduce the rate of delirium in medical patients, and the role of melatonin in reducing the incidence of delirium in surgical patients and critical care unit patients requires further study.

Prevention of Delirium Via Melatonin and Orexin Neurotransmission

The fundamental conception of delirium is altered arousal. In addition, sleep-wake cycle isturbances including insomnia, excessive daytime napping, and disintegration of the xpected circadian patterns have been described as a characteristic component of delirium or decades, and demonstrated to be a core symptom domain of delirium. Although on-pharmacological interventions are successful to some extent, they have limitations due o various biological etiologies for delirium. Among pharmacological interventions, ntipsychotics seem to be effective, but they are not suitable for preventive use because f relatively frequent side-effects such as extrapyramidal symptoms. Recently, new type of rugs for insomnia have been focused with respect to delirium prevention. Recent eta-analyses show effectiveness of melatonin receptor agonists and orexin receptor ntagonists for delirium prevention, and real-world data support them.

Plasma 5-HIAA activity indicative of serotonergic disturbances in cognitively impaired, elderly patients experiencing postoperative delirium

OBJECTIVES

Delirium frequently arises in older demented and non-demented patients in postoperative, clinical settings. To date, the underlying pathophysiological mechanisms remain poorly understood. Monoamine neurotransmitter alterations have been linked to delirium and cognitive impairment. Our aim was to investigate if this holds true in cognitively normal and impaired patients experiencing delirium following hip surgery.

METHODS

Monoamines and metabolites were measured in plasma samples of 181 individuals by means of reversed-phase ultra-high-performance liquid chromatography with electrochemical detection. Delirium and delirium severity were scored with the Confusion Assessment Method and Delirium Rating Scale-Revised-1998. Cognitive function was assessed using the Informant Questionnaire on Cognitive Decline and the Mini-Mental State Examination, multimorbidity with the Charlson Comorbidity Index.

RESULTS

Plasma 5-hydroxyindoleacetic acid (5-HIAA), the major metabolite of serotonin (5-HT), was significantly higher in delirious and non-delirious cognitively impaired subjects as compared to control individuals without delirium and cognitive impairment (p < 0.001 and p = 0.007), which remained highly significant after excluding patients taking psychotropic medication (p < 0.0001 and p = 0.003). No significant differences were found for cognitively normal delirious patients, although serotonergic levels were numerically higher compared to control counterparts.

CONCLUSIONS

Our findings indicate a general serotonergic disturbance in delirious and non-delirious postoperative patients suffering from cognitive impairment. We observed a similar, but less pronounced difference in delirious patients, which suggests serotonergic disturbances may be further aggravated by the co-occurrence of delirium and cognitive impairment.

Melatonin Receptor Agonists for the Prevention of Delirium: An Updated Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Although a previous review illustrated the efficacy of melatonin receptor agonists (MRAs) in preventing delirium, some recent randomized controlled trials (RCTs) did not confirm these effects.

OBJECTIVES

This study systematically reviewed the efficacy, acceptability, and tolerability of MRAs for delirium prevention.

MATERIALS AND METHODS

We searched electronic databases, including Scopus, PubMed, CINAHL, and Controlled Trials Register, from their inception to February 20, 2022. The primary efficacy outcome was delirium incidence rate after MRA administration; relative risks (RRs), overall discontinuation, and discontinuation due to adverse events are also presented.

RESULTS

The overall pooled incidence rates of delirium in MRA-treated and placebo-treated groups were significantly different with RR (95% CI)=0.66(0.52, 0.84, ), I2=59%. Similarly, the incidence rate was significantly lower in the melatonin-treated group than in the placebo-treated group [RR (95% CI) =0.65 (0.49, 0.88), I2=65%]. Unfortunately, incidence rates were not significantly different between ramelteon-treated and placebo-treated groups [RR (95% CI) =0.67 (0.42, 1.08), I2=50%]. The pooled incidence rate of delirium in either melatonin or ramelteon-treated groups was not significantly different from the placebo-treated group in elderly patients. The pooled incidence rate of delirium was significantly lower in the melatonin-treated group than in the benzodiazepinetreated group.

CONCLUSION

Based on this review, melatonin could prevent delirium with a small effect size. However, ramelteon did not show efficacy in preventing delirium. Additionally, neither melatonin nor ramelteon individually showed effectiveness in preventing delirium in elderly patients. Therefore, using MRAs to prevent delirium in clinical practice should be cautious. However, future welldefined and large sample size studies could verify these findings.

Melatonin for prevention of postoperative delirium after lower limb fracture surgery in elderly patients (DELIRLESS): study protocol for a multicentre randomised controlled trial

INTRODUCTION

Postoperative delirium (POD) is one of the most frequent complication after surgery in elderly patients, and is associated with increased morbidity and mortality, prolonged length of stay, cognitive and functional decline leading to loss of autonomy, and important additional healthcare costs. Perioperative inflammatory stress is a key element in POD genesis. Melatonin exhibits antioxidative and immune-modulatory proprieties that are promising concerning delirium prevention, but in perioperative context literature are scarce and conflicting. We hypothesise that perioperative melatonin can reduce the incidence of POD.

METHODS AND ANALYSIS

The DELIRLESS trial is a prospective, national multicentric, phase III, superiority, comparative randomised (1:1) double-blind clinical trial. Among patients aged 70 or older, hospitalised and scheduled for surgery of a severe fracture of a lower limb, 718 will be randomly allocated to receive either melatonin 4 mg per os or placebo, every night from anaesthesiologist preoperative consultation and up to 5 days after surgery. The primary outcome is POD incidence measured by either the French validated translation of the Confusion Assessment Method (CAM) score for patients hospitalised in surgery, or CAM-ICU score for patients hospitalised in ICU (Intensive Care Unit). Daily delirium assessment will take place during 10 days after surgery, or until the end of hospital stay if it is shorter. POD cumulative incidence function will be compared at day 10 between the two randomised arms in a competing risks framework, using the Fine and Grey model with death as a competing risk of delirium.

ETHICS AND DISSEMINATION

The DELIRLESS trial has been approved by an independent ethics committee the Comité de Protection des Personnes (CPP) Sud-Est (ref CPP2020-18-99 2019-003210-14) for all study centres. Participant recruitment begins in December 2020. Results will be published in international peer-reviewed medical journals.

TRIAL REGISTRATION NUMBER

NCT04335968, first posted 7 April 2020.

PROTOCOL VERSION IDENTIFIER

N°3-0, 3 May 2021.

Approach to Altered Mental Status and Inpatient Delirium

Altered mental status is a nonspecific diagnosis that encompasses a wide spectrum of disease and is frequently cited as a reason for both hospital admission and inpatient neurologic consultation. There are numerous etiologies of altered mental status, and so although many are facile with the workup of this potentially life-threatening entity, it can nevertheless be overwhelming. Our goal was to provide a practical framework embedded in a current, comprehensive review of the epidemiology, clinical evaluation, and management of undifferentiated altered mental status. We pay particular attention to the management of a critical yet underdiagnosed subtype of altered mental status: delirium.

Effects of perioperative interventions for preventing postoperative delirium: A protocol for systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Postoperative delirium (POD) not only increases the medical burden but also adversely affects patient prognosis. Although some cases of delirium can be avoided by early intervention, there is no clear evidence indicating whether any of these measures can effectively prevent POD in specific patient groups.

OBJECTIVE

The aim of this meta-analysis was to compare the efficacy and safety of the existing preventive measures for managing POD.

METHODS

The PubMed, OVID (Embase and MEDLINE), Web of Science, and the Cochrane Library databases were searched for articles published before January 2020. The relevant randomized controlled trials (RCTs) were selected based on the inclusion and exclusion criteria. Data extraction and methodological quality assessment were performed according to a predesigned data extraction form and scoring system, respectively. The interventions were compared on the basis of the primary outcome like incidence of POD, and secondary outcomes like duration of delirium and the length of intensive care unit and hospital stay.

RESULTS

Sixty-three RCTs were included in the study, covering interventions like surgery, anesthesia, analgesics, intraoperative blood glucose control, cholinesterase inhibitors, anticonvulsant drugs, antipsychotic drugs, sleep rhythmic regulation, and multi-modal nursing. The occurrence of POD was low in 4 trials that monitored the depth of anesthesia with bispectral index during the operation (P < .0001). Two studies showed that supplementary analgesia was useful for delirium prevention (P = .002). Seventeen studies showed that perioperative sedation with α2-adrenergic receptor agonists prevented POD (P = .0006). Six studies showed that both typical and atypical antipsychotic drugs can reduce the incidence of POD (P = .002). Multimodal nursing during the perioperative period effectively reduced POD in 6 studies (P < .00001). Furthermore, these preventive measures can reduce the duration of delirium, as well as the total and postoperative length of hospitalized stay for non-cardiac surgery patients. For patients undergoing cardiac surgery, effective prevention can only reduce the length of intensive care unit stay.

CONCLUSION

Measures including intraoperative monitoring of bispectral index, supplemental analgesia, α2-adrenergic receptor agonists, antipsychotic drugs, and multimodal care are helpful to prevent POD effectively. However, larger, high-quality RCTs are needed to verify these findings and develop more interventions and drugs for preventing postoperative delirium.

Where should patients with or at risk of delirium be treated in an acute care system? Comparing the rates of delirium in patients receiving usual care vs alternative care: A systematic review and meta-analysis

BACKGROUND

Delirium is an acute condition that occurs in hospitalised patients and leads to poor patient outcomes that can last long term. Therefore, the importance of prevention is undeniable and adopting new models of care for at-risk patients should be prioritised.

OBJECTIVES

This systematic review and meta-analysis will assess the effectiveness of different interventions designed to prevent or manage delirium in acutely unwell hospitalised patients.

METHODS

MEDLINE, EMBASE, PsycINFO, OpenGrey, Web of Science and reference lists of journals were searched. Eligible studies reported on incidence or duration of delirium, used a validated delirium diagnostic tool and compared an intervention to either a control or another intervention group. Meta-analyses were conducted, and GRADEpro software was used to assess the certainty of evidence. This review is registered on PROSPERO.

RESULTS

A total of 59 studies were included and 33 were eligible for meta-analysis. Delirium incidence was most significantly reduced by non-pharmacological multicomponent interventions compared with usual care, with pooled risk ratios of 0.57 (95% CI: 0.44 to 0.73, 10 randomised controlled trials) and 0.47 (95% CI: 0.35 to 0.64, six observational studies). Single-component interventions did not significantly reduce delirium incidence compared with usual care in seven randomised trials (risk ratio = 0.92, 95% CI: 0.81 to 1.04). The most effective single-component intervention in reducing delirium incidence was a hospital-at-home intervention (risk ratio = 0.29, 95% CI: 0.09 to 0.87).

CONCLUSIONS

Non-pharmacological multicomponent interventions are effective in preventing delirium; however, the same cannot be said for other interventions because of uncertain results. There is some evidence that providing multicomponent interventions in patients' homes is more effective than in a hospital setting. Therefore, researching the benefits of hospital-at-home interventions in delirium prevention is recommended.

Comparative effectiveness of pharmacological interventions to prevent postoperative delirium: a network meta-analysis

Many pharmacologic agents were investigated for the effect to prevent delirium. We aimed to comprehensively compare the effect of the pharmacological interventions to prevent postoperative delirium. A Bayesian network meta-analysis of randomized trials was performed using random effects model. PubMed, the Cochrane Central Register of Controlled Trials, and Embase were searched on 20 January 2021. Randomized trials comparing the effect of a drug to prevent postoperative delirium with another drug or placebo in adult patients undergoing any kind of surgery were included. Primary outcome was the postoperative incidence of delirium. Eighty-six trials with 26,992 participants were included. Dexmedetomidine, haloperidol, and atypical antipsychotics significantly decreased the incidence of delirium than placebo [dexmedetomidine: odds ratio 0.51, 95% credible interval (CrI) 0.40-0.66, moderate quality of evidence (QOE); haloperidol: odds ratio 0.59, 95% CrI 0.37-0.95, moderate QOE; atypical antipsychotics: odds ratio 0.27, 95% CrI 0.14-0.51, moderate QOE]. Dexmedetomidine and atypical antipsychotics had the highest-ranking probabilities to be the best. However, significant heterogeneity regarding diagnostic time window as well as small study effects precludes firm conclusion.

Melatonin and melatonergic agents for the prevention of postoperative delirium: A meta-analysis of randomized placebo-controlled trials

Studies on melatonin and melatonergic agents (MMA) for the prevention of postoperative delirium (POD) have produced inconsistent findings. We conducted a meta-analysis to assess the effect of perioperative MMA on the prevention for POD. This meta-analysis is registered in the PROSPERO (CRD42020164900). We searched PubMed, Embase, and Cochrane Library through August 1, 2020 to identify randomized placebo-controlled trials (RCTs) that assessed MMA for the prevention for POD in adult patients undergoing surgery. The primary outcome was POD. Relative risk (RR) with 95% confidence interval (CI) was pooled using a random-effects model. Nine RCTs with 1452 patients were included. The incidence of POD was 23.8% (173/726) and 24.4% (177/726) in the MMA and placebo groups, respectively. Compared with placebo, MMA did not reduce the occurrence of POD (9 trails, 1452 patients, RR 0.93, 95% CI 0.70-1.24), with modest heterogeneity (I² = 40%). Sensitivity analyses suggested that MMA also did not reduce the occurrence of POD in elderly patients (age ≥65 years) (6 trails, 810 patients, RR 0.71, 95% CI 0.38-1.32), patients given melatonin (4 trails, 806 patients, RR 0.78, 95% CI 0.43-1.41) or ramelteon (4 trails, 345 patients, RR 0.89, 95% CI 0.44-1.78), and patients undergoing general anesthesia (4 trails, 681 patient, RR 1.02, 95% CI 0.82-1.28). Based on the current evidence, perioperative MMA may have no effect on the prevention of POD.

Sleep and circadian rhythm disturbances in intensive care unit (ICU)-acquired delirium: a case-control study

OBJECTIVE

The relationships among sleep, circadian rhythm, and intensive care unit (ICU)-acquired delirium are complex and remain unclear. This study aimed to examine the pathophysiological mechanisms of sleep and circadian rhythm disturbances in patients with ICU-acquired delirium.

METHODS

This study included critical adult patients aged 18 to 75 years who were treated in the ICU. Twenty-four-hour polysomnography was performed and serum melatonin and cortisol levels were measured six times during polysomnography. Receiver operating characteristic curves and binomial logistic regression were used to evaluate the potential of sleep, melatonin, and cortisol as indicators of delirium in the ICU.

RESULTS

Patients with delirium (n = 24) showed less rapid eye movement (REM) sleep compared with patients without delirium (n = 24, controls). Melatonin levels were lower and cortisol levels were higher in the delirium group than in the control group. REM sleep, melatonin, and cortisol were significantly associated with delirium. The optimal cutoff values of REM sleep and mean melatonin and cortisol levels that predicted delirium were ≤1.05%, ≤422.09 pg/mL, and ≥212.14 ng/mL, respectively.

CONCLUSIONS

REM sleep, and melatonin and cortisol levels are significantly associated with the risk of ICU-acquired delirium. Improved sleep and readjustment of circadian rhythmicity may be therapeutic targets of ICU-acquired delirium.

Insight into the roles of melatonin in bone tissue and bone‑related diseases (Review)

Bone‑related diseases comprise a large group of common diseases, including fractures, osteoporosis and osteoarthritis (OA), which affect a large number of individuals, particularly the elderly. The progressive destruction and loss of alveolar bone caused by periodontitis is a specific type of bone loss, which has a high incidence and markedly reduces the quality of life of patients. With the existing methods of prevention and treatment, the incidence and mortality of bone‑related diseases are still gradually increasing, creating a significant financial burden to societies worldwide. To prevent the occurrence of bone‑related diseases, delay their progression or reverse the injuries they cause, new alternative or complementary treatments need to be developed. Melatonin exerts numerous physiological effects, including inducing anti‑inflammatory and antioxidative functions, resetting circadian rhythms and promoting wound healing and tissue regeneration. Melatonin also participates in the health management of bone and cartilage. In the present review, the potential roles of melatonin in the pathogenesis and progression of bone injury, osteoporosis, OA and periodontitis are summarized. Furthermore, the high efficiency and diversity of the physiological regulatory effects of melatonin are highlighted and the potential benefits of the use of melatonin for the clinical prevention and treatment of bone‑related diseases are discussed.

Delirium REduction after administration of melatonin in acute ischemic stroke (DREAMS): A propensity score-matched analysis

BACKGROUND AND PURPOSE

Poststroke delirium (PSD) comprises a common and severe complication after stroke. However, treatment options for PSD remain insufficient. We investigated whether prophylactic melatonin supplementation may be associated with reduced risk for PSD.

METHODS

Consecutive patients admitted to the Tübingen University Stroke Unit, Tübingen, Germany, with acute ischemic stroke (AIS), who underwent standard care between August 2017 and December 2017, and patients who additionally received prophylactic melatonin (2 mg per day at night) within 24 h of symptom onset between August 2018 and December 2018 were included. Primary outcomes were (i) PSD prevalence in AIS patients and (ii) PSD risk and PSD-free survival in patients with cerebral infarction who underwent melatonin supplementation compared to propensity score-matched (PSM) controls. Secondary outcomes included time of PSD onset and PSD duration.

RESULTS

Out of 465 (81.2%) patients with cerebral infarction and 108 (18.8%) transient ischemic attack (TIA) patients, 152 (26.5%) developed PSD (median time to onset [IQR]: 16 [8-32] h; duration 24 [8-40] h). Higher age, cerebral infarction rather than TIA, and higher National Institutes of Health Stroke Scale score and aphasia on admission were significant predictors of PSD. After PSM (164 melatonin-treated patients with cerebral infarction versus 164 matched controls), 42 (25.6%) melatonin-treated patients developed PSD versus 60 (36.6%) controls (odds ratio, 0.597; 95% confidence interval, 0.372-0.958; p = 0.032). PSD-free survival differed significantly between groups (p = 0.027), favoring melatonin-treated patients. In patients with PSD, no between-group differences in the time of PSD onset and PSD duration were noted.

CONCLUSIONS

Patients prophylactically treated with melatonin within 24 h of AIS onset had lower risk for PSD than patients undergoing standard care. Prospective randomized trials are warranted to corroborate these findings.

Evaluation of Delirium in Critically Ill Patients Prescribed Melatonin or Ramelteon

BACKGROUND

An impaired sleep-wake cycle may be one factor that affects the development of delirium in critically ill patients. Several small studies suggest that exogenous melatonin or ramelteon may decrease the incidence and/or duration of delirium.

OBJECTIVE

To compare the effect of prophylactic administration of melatonin, ramelteon, or no melatonin receptor agonist on the development of delirium in the intensive care unit (ICU).

METHODS

This was a single-center, retrospective, observational cohort study of nondelirious patients in the ICU who received melatonin, ramelteon, or no melatonin receptor agonist. The primary end point was the incidence of delirium. Secondary end points included assessments of daily level of sedation and daily utilization of antipsychotic, sedative, and opioid agents.

RESULTS

No difference was observed in the incidence of delirium among the melatonin, ramelteon, and placebo cohorts (18.7% vs 14.3% vs 13.8%; P = 0.77). A difference was observed in the rate of agitation and sedation among the 3 groups, with the greatest observed in the melatonin cohort. Additionally, there was a difference in the use of propofol, dexmedetomidine, and opioids. Overall, there was no difference in clinical outcomes, including duration of mechanical ventilation and ICU or hospital length of stay.

CONCLUSION AND RELEVANCE

Therapy with melatonin, ramelteon, and no melatonin receptor agonist resulted in similar rates of delirium in a mixed ICU population. Despite significant differences in agitation, sedation, and medication utilization, there was no differences in the clinical outcomes evaluated.

A retrospective study of factors associated with persistent delirium

BACKGROUND

It has been reported that delirium causes various problems. Many researchers have reported the risk factors associated with the onset of delirium; however, there are few reports focused on persistent delirium. This study aimed to identify the risk factors associated with persistent delirium.

METHODS

A total of 573 patients hospitalised in Nara Prefecture General Medical Centre from October 2014 through September 2017 who were referred to the psychiatry consultation service were included in this study. Persistent delirium was defined as delirium lasting for 14 days or more. A retrospective study was carried out based on the patients' records. The relationship between various background factors and persistent delirium was statistically analysed.

RESULTS

Of the 573 hospitalised patients, 295 were diagnosed as having delirium. Forty-six patients with persistent delirium and 181 patients with nonpersistent delirium were included in this study. Multivariable logistic regression analyses revealed that male gender, opioid analgesics use, non-opioid analgesics use, and low serum sodium were significantly and independently associated with persistent delirium. Ramelteon or trazodone was used significantly more in persistent delirium, although each use was not significant.

CONCLUSION

This is the first study to reveal that male gender and use of analgesics were associated with persistent delirium in general hospital. However, as this is a case-control study and may contain bias, future cohort studies and intervention studies are needed. It is also necessary to investigate the relevance of the 'degree of pain' behind the use of analgesics.

Implementation of a multicomponent intervention sign to reduce delirium in orthopaedic inpatients (MIND-ORIENT): a quality improvement project

Delirium is a serious and common condition that leads to significant adverse health outcomes for hospitalised older adults. It occurs in 30%–55% of patients with hip fractures and is one of the most common postoperative complications in older adults undergoing orthopaedic surgery. Multicomponent, non-pharmacological interventions can reduce delirium incidence by up to 30% but are often challenging to implement as part of routine care. We identified a gap in the delivery of non-pharmacological interventions on an orthopaedic unit. This project aimed to implement a bedside sign on an orthopaedic unit to reduce the occurrence of delirium by prompting staff to use multicomponent evidence-based delirium prevention strategies for at-risk older adults. Quality improvement methods were used to integrate and optimise the use of a bedside ‘delirium prevention’ sign on an orthopaedic unit.

The sign was implemented in four target rooms and sign completion rates increased from 47% to 83% (95% CI 71.7% to 94.9%; p<0.001) over a 10-month period. The sign did not have a significant impact on delirium prevalence. The mean Confusion Assessment Method (CAM)+ rate during the baseline period was 8% with an absolute increase in the intervention period to 11.4% (95% CI 7.2% to 15.8%; p=0.31). There were no significant shifts or trends in the run chart for the proportion of patients with CAM+ scores over time. The sign was well received by staff, who reported it was a worthwhile use of time and prompted use of non-pharmacological interventions. This quality improvement project successfully integrated a novel, low-cost, feasible and evidence-based approach into routine clinical care to support staff to deliver non-pharmacological interventions. Given the increased pressures on front-line staff in hospital, tools that reduce cognitive load at the bedside are important to consider when caring for a vulnerable older adult patient population.

Pharmacological strategies to prevent postoperative delirium: a systematic review and network meta-analysis

Background

Postoperative delirium (POD) is a condition of cerebral dysfunction and a common complication after surgery. This study aimed to compare and determine the relative efficacy of pharmacological interventions for preventing POD using a network meta-analysis.

Methods

We performed a systematic and comprehensive search to identify and analyze all randomized controlled trials until June 29, 2020, comparing two or more pharmacological interventions, including placebo, to prevent or reduce POD. The primary outcome was the incidence of POD. We performed a network meta-analysis and used the surface under the cumulative ranking curve (SUCRA) values and rankograms to present the hierarchy of the pharmacological interventions evaluated.

Results

According to the SUCRA value, the incidence of POD decreased in the following order: the combination of propofol and acetaminophen (86.1%), combination of ketamine and dexmedetomidine (86.0%), combination of diazepam, flunitrazepam, and pethidine (84.8%), and olanzapine (75.6%) after all types of anesthesia; combination of propofol and acetaminophen (85.9%), combination of ketamine and dexmedetomidine (83.2%), gabapentin (82.2%), and combination of diazepam, flunitrazepam, and pethidine (79.7%) after general anesthesia; and ketamine (87.1%), combination of propofol and acetaminophen (86.0%), and combination of dexmedetomidine and acetaminophen (66.3%) after cardiac surgery. However, only the dexmedetomidine group showed a lower incidence of POD than the control group after all types of anesthesia and after general anesthesia.

Conclusions

Dexmedetomidine reduced POD compared with the control group. The combination of propofol and acetaminophen and the combination of ketamine and dexmedetomidine seemed to be effective in preventing POD. However, further studies are needed to determine the optimal pharmacological intervention to prevent POD.

Statistical analysis plan for the Prophylactic Melatonin for Delirium in Intensive Care (ProMEDIC): a randomised controlled trial

Rationale

Delirium is defined as acute organic brain dysfunction characterised by inattention and disturbance of cognition. It is common in the intensive care unit and is associated with poorer outcomes. Good quality sleep is important in the prevention and management of delirium. Melatonin is a natural hormone secreted by the pineal gland which helps in the regulation of the sleep-wake cycle. It is possible that melatonin supplementation in intensive care improves sleep and prevents delirium.

Methods and design

The ‘Prophylactic Melatonin for Delirium in Intensive Care’ study is a multi-centre, randomised, double-blinded, placebo-controlled trial. The primary objective of this study is to determine whether melatonin given prophylactically decreases delirium in critically ill patients. A total of 850 ICU patients have been randomised (1:1) to receive either melatonin or a placebo. Participants were monitored twice daily for symptoms of delirium.

Results

This paper and the attached additional files describe the statistical analysis plan (SAP) for the trial. The SAP has been developed and submitted for publication before the database has been locked and before the treatment allocation has been unblinded. The SAP contains details of analyses to be undertaken, which will be reported in the primary and secondary publications.

Discussion

The SAP details the analyses that will be done to avoid bias coming from knowledge of the results in advance. This trial will determine whether prophylactic melatonin administered to intensive care unit patients helps decrease the rate and the severity of delirium.

Trial registration

Australian and New Zealand Clinical Trial Registry (ANZCTR) ACTRN1261600043647, registration date: 06 April 2016. WHO Trial Number – U1111-1175-1814

Effects of Ramelteon on the Prevention of Postoperative Delirium in Older Patients Undergoing Orthopedic Surgery: The RECOVER Randomized Controlled Trial

OBJECTIVES

Postoperative delirium, associated with negative consequences including longer hospital stays and worse cognitive and physical outcomes, is frequently accompanied by sleep-wake disturbance. Our objective was to evaluate the efficacy and short-term safety of ramelteon, a melatonin receptor agonist, for the prevention of postoperative delirium in older patients undergoing orthopedic surgery.

DESIGN

A quadruple-masked randomized placebo-controlled trial (Clinical Trials.gov NCT02324153) conducted from March 2017 to June 2019.

SETTING

Tertiary academic medical center.

PARTICIPANTS

Patients aged 65 years or older, undergoing elective primary or revision hip or knee replacement.

INTERVENTION

Ramelteon (8 mg) or placebo MEASUREMENTS: Eighty participants were randomized to an oral gel cap of ramelteon or placebo for 3 consecutive nights starting the night before surgery. Trained research staff conducted delirium assessments for 3 consecutive days starting on postoperative day (POD) 0, after recovery from anesthesia, and on to POD2. A delirium diagnosis was based upon DSM-5 criteria determined by expert panel consensus.

RESULTS

Of 80 participants, five withdrew consent (one placebo, four ramelteon) and four were excluded (four ramelteon) after randomization. Delirium incidence during the 2 days following surgery was 7% (5 of 71) with no difference between the ramelteon versus placebo: 9% (3 of 33) and 5% (2 of 38), respectively. The adjusted odds ratio for postoperative delirium as a function of assignment to the ramelteon treatment arm was 1.28 (95% confidence interval: 0.21-7.93; z-value 0.27; p-value = 0.79). Adverse events were similar between the two groups.

CONCLUSION

In older patients undergoing elective primary or revision hip or knee replacement, ramelteon was not efficacious in preventing postoperative delirium.

Melatonin for delirium prevention in hospitalized patients: A systematic review and meta-analysis

BACKGROUND AND AIMS

Melatonin, a pineal gland hormone is reported to have a protective effect against delirium. This systematic review and meta-analysis explores the effect of melatonin and melatonin receptor agonist, ramelteon on delirium prevention in adult hospitalized patients.

METHODS

Randomized Controlled trials of melatonin/ramelteon published up to May 7, 2020 were identified from MEDLINE, PREMEDLINE, Embase, PsycINFO, the Cochrane Central Register of Controlled trials, PubMed, and Google Scholar. The primary outcome was delirium incidence. The secondary outcomes were sleep quality, sedation score, sedatives requirement, delirium duration, length of hospital stay, length of Intensive Care Unit (ICU) stay, mortality and adverse events. A meta-analysis with a random-effects models was performed. Estimates were presented as Risk Ratio (RR) or Mean Differences (MD) with 95% Confidence Interval (CI).

FINDINGS

Fourteen studies with 1712 participants were included. Melatonin/ramelteon significantly reduced delirium incidence (RR 0·61, 95% CI 0·42-0·89, p 0·009) with risk reduction of 49% in surgical patients and 34% in ICU patients. Non-significant reduction was found in medical patients. Melatonin/ramelteon were associated with improvement in sleep quality, increased sedation score and lower sedatives consumption. However, they did not reduce delirium duration, length of hospital stay, length of ICU stay and mortality. Hallucinations, nightmares and gastrointestinal disorders were prevalent in melatonin group.

INTERPRETATION

Melatonin/ramelteon are associated with reduction in delirium incidence in hospitalized patients. However, this effect seems confined to surgical and ICU patients. The optimum dosage and formulation of melatonin, and treatment duration remain uncleared and open to further studies with larger sample sizes.

The Role of Perioperative Sleep Disturbance in Postoperative Neurocognitive Disorders

Postoperative neurocognitive disorder (PND) increases the length of hospital stay, mortality, and risk of long-term cognitive impairment. Perioperative sleep disturbance is prevalent and commonly ignored and may increase the risk of PND. However, the role of perioperative sleep disturbances in PND remains unclear. Nocturnal sleep plays an indispensable role in learning, memory, and maintenance of cerebral microenvironmental homeostasis. Hospitalized sleep disturbances also increase the incidence of postoperative delirium and cognitive dysfunction. This review summarizes the role of perioperative sleep disturbances in PND and elucidates the potential mechanisms underlying sleep-deprivation-mediated PND. Activated neuroinflammation and oxidative stress; impaired function of the blood-brain barrier and glymphatic pathway; decreased hippocampal brain-derived neurotrophic factor, adult neurogenesis, and sirtuin1 expression; and accumulated amyloid-beta proteins are associated with PND in individuals with perioperative sleep disorders. These findings suggest that the improvement of perioperative sleep might reduce the incidence of postoperative delirium and postoperative cognitive dysfunction. Future studies should further investigate the role of perioperative sleep disturbance in PND.

The Effect of Multiple Assessments on Delirium Detection: a Pilot Study

Background

Delirium is characterized by fluctuating attention or arousal, with high prevalence in the orthopaedic ward. Our aim was to: 1) establish the prevalence of delirium on an orthopaedic ward, and 2) compare delirium prevalence using a single geriatrician assessment vs. multiple 3D-CAM (3-Minute Diagnostic Interview for Confusion Assessment Method) assessments during the day. We hypothesized that multiple assessments would increase the detection rate due to the fluctuating nature of delirium.

Methods

Comparative study conducted at an academic hospital in Hamilton, Ontario. Participants included patients 65 years and older admitted to the orthopaedic ward (n=55). After a geriatrician made the first assessment of delirium by 3D-CAM on each patient, teams with specialized geriatrics training re-assessed participants up to four times. Delirium rates based on first assessment were compared to cumulative end-of-day rates to determine if detection increased with multiple assessments.

Results

The prevalence of delirium was 30.9% (17 participants) using multiple assessments. Of these cases, 13 (76.4%) were detected in the initial geriatrician assessment. In patients with hip fractures, 70.6% (12 of 17) were identified as delirious by multiple assessments.

Conclusion

As symptoms fluctuate, multiple daily CAM assessments may increase the identification of delirium in orthopaedic inpatients.

Circadian Disruption in Critical Illness

Circadian rhythms play a vital role in metabolic, hormonal, and immunologic function and are often disrupted in patients in the ICU. Circadian rhythms modulate the molecular machinery that responds to injury and illness which can impact recovery. Potential factors contributing to the alteration in circadian rhythmicity in intensive care unit (ICU) patients include abnormal lighting, noise, altered feeding schedules, extensive patient care interactions and medications. These alterations in circadian rhythms in ICU patients may affect outcomes and therefore, normalization of circadian rhythmicity in critically ill patients may be an important part of ICU care.

Multi-disciplinary and pharmacological interventions to reduce post-operative delirium in elderly patients: A systematic review and meta-analysis

STUDY OBJECTIVE

An estimated 80% of older people undergoing surgery develop postoperative delirium (POD) making them a high-risk group. Research in this area is growing fast but there is no established consensus on strategies for POD prevention or management. A systematic review and meta-analysis were conducted to synthesise data on clinical interventions used to reduce POD among older people undergoing elective and emergency surgery.

METHODS

A range of database searches generated 336 papers. A total of 25 studies met the inclusion criteria and were assessed using the Joanna Briggs Institute Critical Appraisal Checklist. The studies were undertaken across the world.

RESULTS

This review identified a range of intervention approaches: comparisons between anaesthetic and sedatives agents, medication-specific interventions and multidisciplinary models of care. Results found more consistencies across multidisciplinary interventions than the pharmacological interventions. In pooled analyses, haloperidol (OR 0.74; 95% CI (confidence interval) 0.44, 1.26) was not statistically significantly associated with reduced POD incidence any more than a placebo.

CONCLUSION

There is a need to implement multidisciplinary interventions, as well as collaboration between clinicians on pre- and postoperative care practices regarding pharmacological interventions to more effectively reduce and manage POD in older people.

American Society for Enhanced Recovery and Perioperative Quality Initiative Joint Consensus Statement on Postoperative Delirium Prevention

Postoperative delirium is a geriatric syndrome that manifests as changes in cognition, attention, and levels of consciousness after surgery. It occurs in up to 50% of patients after major surgery and is associated with adverse outcomes, including increased hospital length of stay, higher cost of care, higher rates of institutionalization after discharge, and higher rates of readmission. Furthermore, it is associated with functional decline and cognitive impairments after surgery. As the age and medical complexity of our surgical population increases, practitioners need the skills to identify and prevent delirium in this high-risk population. Because delirium is a common and consequential postoperative complication, there has been an abundance of recent research focused on delirium, conducted by clinicians from a variety of specialties. There have also been several reviews and recommendation statements; however, these have not been based on robust evidence. The Sixth Perioperative Quality Initiative (POQI-6) consensus conference brought together a team of multidisciplinary experts to formally survey and evaluate the literature on postoperative delirium prevention and provide evidence-based recommendations using an iterative Delphi process and Grading of Recommendations Assessment, Development and Evaluation (GRADE) Criteria for evaluating biomedical literature.

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.

Assessment of Melatonergics in Prevention of Delirium: A Systematic Review and Meta-Analysis

Background: Delirium is a commonly found comorbidity in hospitalized patients and is associated with adverse outcomes. Melatonin is an endogenous hormone that exerts multiple biological effects, mainly in regulating diurnal rhythms and in inflammatory process and immune responses. We aimed to assess the efficacy of exogenous melatonergics in the prevention of delirium.

Methods: We conducted a search to identify relevant randomized controlled studies (RCTs) in PubMed, Cochrane Library, and EMBASE databases that had been published up to December 2019. Hospitalized adult patients administered melatonergics were included. The primary outcome measure was the incidence of delirium. The secondary outcome measure was the length of stay in intensive care unit (ICU-LOS). The pooled effects were analyzed as the risk ratio (RR) for delirium incidence, weighted mean difference (WMD) for ICU-LOS, and 95% confidence intervals (CIs).

Results: Nine RCTs with 1,210 patients were included. The forest plots showed that melatonergics were associated with a decreasing incidence of delirium (RR, 0.51; 95% CI, 0.30–0.85; I² = 70%; p = 0.01). There was no significant difference in ICU-LOS (WMD, −0.08; 95% CI, −0.19–0.03; I² = 0; p = 0.17).

Conclusion: Administration of exogenous melatonergics to hospitalized patients seems to be associated with a decreasing incidence of delirium.

PROSPERO registration number: CRD42019138863.

The pharmacotherapeutic management of postoperative delirium: an expert update

INTRODUCTION

Postoperative delirium is a common sequela in older adults in the peri-operative period leading to poor outcomes with a complex pathophysiology which has led to a variety of different pharmacologic agents employed in attempts to prevent and treat this syndrome. No pharmacologic agent has been approved to treat this disorder, but this review discusses the pharmacologic strategies which have been tried based on the hypotheses of the causation of the syndrome including neurotransmitter imbalance, inflammation, and oxidative stress.

AREAS COVERED

Systematic reviews and meta-analyses of randomized clinical trials (RCTs) were included via search of electronic databases specifically for the terms postoperative delirium and pharmacologic treatments. With this approach, the recurrent topics of analgesia and sedation, antipsychotics, acetylcholinesterase inhibitors (AchE-Is), inflammation, and melatonin were emphasized and provided the outline for this review.

EXPERT OPINION

Research evidence does not support any particular agent in any of the pharmacologic classes reviewed. However, there is some potential benefit with dexmedetomidine, melatonin, and the monitoring of anesthetic agents all of which need further clinical trials to validate these conclusions. Exploration of ways to improve studies and the application of novel pharmacologic agents may offer future benefit.