Suvorexant is associated with a low incidence of delirium in critically ill patients: a retrospective cohort study

Preventive Effects of Ramelteon, Suvorexant, and Lemborexant on Delirium in Hospitalized Patients With Physical Disease: A Retrospective Cohort Study

BACKGROUND

New sleep-inducing drugs (eg, ramelteon, suvorexant, and lemborexant) have been shown to prevent delirium in high-risk groups. However, no single study has simultaneously evaluated the delirium-preventing effects of all novel sleep-inducing drugs in hospitalized patients. Therefore, this study aimed to clarify the relationship between sleep-inducing drugs and delirium prevention in patients hospitalized in general medical-surgical settings for nonpsychiatric conditions who underwent liaison interventions for insomnia.

METHODS

This retrospective cohort study included patients treated in general medical-surgical settings for nonpsychiatric conditions with consultation-liaison psychiatry consult for insomnia. Delirium was diagnosed by fully certified psychiatrists using the Diagnostic and Statistical Manual of Mental Disorders 5 th edition. The following items were retrospectively examined from medical records as factors related to delirium development: type of sleep-inducing drugs, age, sex, and delirium risk factors. The risk factors of delirium development were calculated using adjusted odds ratios (aORs) via multivariate logistic regression analysis.

RESULTS

Among the 710 patients analyzed, 257 (36.2%) developed delirium. Suvorexant (aOR, 0.61; 95% confidence interval [CI], 0.40-0.94; P = 0.02) and lemborexant (aOR, 0.23; 95% CI, 0.14-0.39; P < 0.0001) significantly reduced the risk of developing delirium. Benzodiazepines (aOR, 1.90; 95% CI, 1.15-3.13; P = 0.01) significantly increased this risk. Ramelteon (aOR, 1.30; 95% CI, 0.84-2.01; P = 0.24) and Z-drugs (aOR, 1.27; 95% CI, 0.81-1.98; P = 0.30) were not significantly associated with delirium development.

CONCLUSIONS

The use of suvorexant and lemborexant may prevent delirium in patients with a wide range of medical conditions.

Pharmacologic Sleep Aids in the Intensive Care Unit: A Systematic Review

Background: Patients in the intensive care unit (ICU) often experience poor sleep quality. Pharmacologic sleep aids are frequently used as primary or adjunctive therapy to improve sleep, although their benefits in the ICU remain uncertain. This review aims to provide a comprehensive assessment of the objective and subjective effects of medications used for sleep in the ICU, as well as their adverse effects. Methods: PubMed, Web of Science, Scopus, Embase, and Cochrane Central Register of Controlled Trials were systematically searched from their inception until June 2023 for comparative studies assessing the effects of pharmacologic sleep aids on objective and subjective metrics of sleep. Results: Thirty-four studies with 3498 participants were included. Medications evaluated were melatonin, ramelteon, suvorexant, propofol, and dexmedetomidine. The majority of studies were randomized controlled trials. Melatonin and dexmedetomidine were the best studied agents. Objective sleep metrics included polysomnography (PSG), electroencephalography (EEG), bispectral index, and actigraphy. Subjective outcome measures included patient questionnaires and nursing observations. Evidence for melatonin as a sleep aid in the ICU was mixed but largely not supportive for improving sleep. Evidence for ramelteon, suvorexant, and propofol was too limited to offer definitive recommendations. Both objective and subjective data supported dexmedetomidine as an effective sleep aid in the ICU, with PSG/EEG in 303 ICU patients demonstrating increased sleep duration and efficiency, decreased arousal index, decreased percentage of stage N1 sleep, and increased absolute and percentage of stage N2 sleep. Mild bradycardia and hypotension were reported as side effects of dexmedetomidine, whereas the other medications were reported to be safe. Several ongoing studies have not yet been published, mostly on melatonin and dexmedetomidine. Conclusions: While definitive conclusions cannot be made for most medications, dexmedetomidine improved sleep quantity and quality in the ICU. These benefits need to be balanced with possible hemodynamic side effects.

Effect of Atypical Sleep EEG Patterns on Weaning From Prolonged Mechanical Ventilation

BACKGROUND

Approximately one-third of acute ICU patients display atypical sleep patterns that cannot be interpreted by using standard EEG criteria for sleep. Atypical sleep patterns have been associated with poor weaning outcomes in acute ICUs.

RESEARCH QUESTION

Do patients being weaned from prolonged mechanical ventilation experience atypical sleep EEG patterns, and are these patterns linked with weaning outcomes?

STUDY DESIGN AND METHODS

EEG power spectral analysis during wakefulness and overnight polysomnogram were performed on alert, nondelirious patients at a long-term acute care facility.

RESULTS

Forty-four patients had been ventilated for a median duration of 38 days at the time of the polysomnogram study. Eleven patients (25%) exhibited atypical sleep EEG. During wakefulness, relative EEG power spectral analysis revealed higher relative delta power in patients with atypical sleep than in patients with usual sleep (53% vs 41%; P < .001) and a higher slow-to-fast power ratio during wakefulness: 4.39 vs 2.17 (P < .001). Patients with atypical sleep displayed more subsyndromal delirium (36% vs 6%; P = .027) and less rapid eye movement sleep (4% vs 11% total sleep time; P < .02). Weaning failure was more common in the atypical sleep group than in the usual sleep group: 91% vs 45% (P = .013).

INTERPRETATION

This study provides the first evidence that patients in a long-term acute care facility being weaned from prolonged ventilation exhibit atypical sleep EEG patterns that are associated with weaning failure. Patients with atypical sleep EEG patterns had higher rates of subsyndromal delirium and slowing of the wakeful EEG, suggesting that these two findings represent a biological signal for brain dysfunction.

Intensive care unit interventions to promote sleep and circadian biology in reducing incident delirium: a scoping review

RATIONALE/OBJECTIVES

Despite plausible pathophysiological mechanisms, research is needed to confirm the relationship between sleep, circadian rhythm and delirium in patients admitted to the intensive care unit (ICU). The objective of this review is to summarise existing studies promoting, in whole or in part, the normalisation of sleep and circadian biology and their impact on the incidence, prevalence, duration and/or severity of delirium in ICU.

METHODS

A sensitive search of electronic databases and conference proceedings was completed in March 2023. Inclusion criteria were English-language studies of any design that evaluated in-ICU non-pharmacological, pharmacological or mixed intervention strategies for promoting sleep or circadian biology and their association with delirium, as assessed at least daily. Data were extracted and independently verified.

RESULTS

Of 7886 citations, we included 50 articles. Commonly evaluated interventions include care bundles (n=20), regulation or administration of light therapy (n=5), eye masks and/or earplugs (n=5), one nursing care-focused intervention and pharmacological intervention (eg, melatonin and ramelteon; n=19). The association between these interventions and incident delirium or severity of delirium was mixed. As multiple interventions were incorporated in included studies of care bundles and given that there was variable reporting of compliance with individual elements, identifying which components might have an impact on delirium is challenging.

CONCLUSIONS

This scoping review summarises the existing literature as it relates to ICU sleep and circadian disruption (SCD) and delirium in ICU. Further studies are needed to better understand the role of ICU SCD promotion interventions in delirium mitigation.

Orexin receptor antagonists versus antipsychotics for the management of delirium in intensive care unit patients with cardiovascular disease: A retrospective observational study

OBJECTIVE

Although antipsychotics are often used in the pharmacological treatment of delirium, recent reports suggest the efficacy of orexin receptor antagonists. This study investigated whether orexin receptor antagonists could be a possible treatment option for delirium.

METHOD

A nonblinded nonrandomized routine clinical treatment was performed. Patients treated in intensive care units (ICU) for cardiovascular disease and receiving psychiatric intervention were studied retrospectively. The scores from the Intensive Care Delirium Screening Checklist (ICDSC) were compared between patients treated with orexin receptor antagonists and those treated with antipsychotics.

RESULTS

The mean (standard deviation) ICDSC scores were 4.5 (1.8) at day -1 and 2.6 (2.6) at day 7 for orexin receptor antagonist group (n = 25) and 4.6 (2.4) at day -1 and 4.1 (2.2) at day 7 for antipsychotic group (n = 28). The orexin receptor antagonist group showed significantly lower ICDSC scores than the antipsychotic group (p = 0.021).

CONCLUSION

While precise efficacy cannot be determined from our retrospective, observational, and uncontrolled pilot study, this analysis encourages a future double-blind randomized placebo-controlled trial of orexin-antagonists for delirium treatment.

Causes, Consequences, and Treatments of Sleep and Circadian Disruption in the ICU: An Official American Thoracic Society Research Statement

Background: Sleep and circadian disruption (SCD) is common and severe in the ICU. On the basis of rigorous evidence in non-ICU populations and emerging evidence in ICU populations, SCD is likely to have a profound negative impact on patient outcomes. Thus, it is urgent that we establish research priorities to advance understanding of ICU SCD. Methods: We convened a multidisciplinary group with relevant expertise to participate in an American Thoracic Society Workshop. Workshop objectives included identifying ICU SCD subtopics of interest, key knowledge gaps, and research priorities. Members attended remote sessions from March to November 2021. Recorded presentations were prepared and viewed by members before Workshop sessions. Workshop discussion focused on key gaps and related research priorities. The priorities listed herein were selected on the basis of rank as established by a series of anonymous surveys. Results: We identified the following research priorities: establish an ICU SCD definition, further develop rigorous and feasible ICU SCD measures, test associations between ICU SCD domains and outcomes, promote the inclusion of mechanistic and patient-centered outcomes within large clinical studies, leverage implementation science strategies to maximize intervention fidelity and sustainability, and collaborate among investigators to harmonize methods and promote multisite investigation. Conclusions: ICU SCD is a complex and compelling potential target for improving ICU outcomes. Given the influence on all other research priorities, further development of rigorous, feasible ICU SCD measurement is a key next step in advancing the field.

Reducing the effect of immortal time bias affects the analysis of prevention of delirium by suvorexant in critically ill patients: A retrospective cohort study

BACKGROUND

Studies assessing the effect of suvorexant on delirium prevention included patients treated before development of delirium, which can introduce immortal time bias. The objective of the present study was to evaluate the effect of suvorexant on delirium, comparing patients treated before the onset of delirium with patients treated within 72h of admission using the same dataset.

METHODS

Data from adult patients admitted to the ICU from August 2018 to July 2021 were retrospectively analyzed. In "any time before" analysis, the incidence of delirium was compared for patients who received suvorexant at any time during their ICU stay (suvorexant) (unless delirium developed before treatment) with patients who either did not receive suvorexant or received suvorexant after development of delirium (control). This design was used in previously published studies. In "within 72h" analysis, the incidence of delirium was compared for patients who received suvorexant within 72 hours of admission (suvorexant) and patients who did not receive suvorexant or received it more than 72 hours after admission (control). Patients who developed delirium during the initial 72 hours were excluded from "within 72h" analysis (N = 799).

RESULTS

"Within 72h" analysis included 1,255 patients, and "any time before" analysis included 2,054 patients (of 6599 admissions). The unadjusted hazard ratio of "any time before" analysis was 0.16 and the 95% confidence interval was 0.13-0.21 (p<0.01). The adjusted hazard ratio was 0.21, and the 95% confidence interval was 0.16-0.27 (p<0.01). "Within 72h" analysis had an unadjusted hazard ratio of 0.54 and the 95% confidence interval was 0.36-0.82 (p<0.01). However, this association lost statistical significance after adjustment for potential confounders (adjusted hazard ratio 1.02, 95% confidence interval 0.65-1.59, p = 0.93).

CONCLUSION

Reducing the effect of immortal time bias led to a significantly reduced effect of suvorexant for the prevention of delirium.

Sleep Spindles and K-Complexes Are Favorable Prognostic Biomarkers in Critically Ill Patients

SUMMARY

In this narrative review, we summarize recent research on the prognostic significance of biomarkers of sleep in continuous EEG and polysomnographic recordings in intensive care unit patients. Recent studies show the EEG biosignatures of non-rapid eye movement 2 sleep (sleep spindles and K-complexes) on continuous EEG in critically ill patients better predict functional outcomes and mortality than the ictal-interictal continuum patterns. Emergence of more complex and better organized sleep architecture has been shown to parallel neurocognitive recovery and correlate with functional outcomes in traumatic brain injury and strokes. Particularly interesting are studies which suggest intravenous dexmedetomidine may induce a more biomimetic non-rapid eye movement sleep state than intravenous propofol, potentially providing more restorative sleep and lessening delirium. Protocols to improve intensive care unit sleep and neurophysiological studies evaluating the effect of these on sleep and sleep architecture are here reviewed.

Suvorexant with or without ramelteon to prevent delirium: a systematic review and meta-analysis

Delirium is a common and serious neurobehavioral syndrome, associated with prolonged hospital stays, and increased morbidity and mortality. As it remains unclear whether suvorexant with or without ramelteon prevents delirium in elderly hospitalized patients, we conducted a systematic review and meta-analysis to evaluate, searching the PubMed, Cochrane Library, Web of Science, EMBASE, and EBSCOhost databases for all randomized controlled trials (RCTs), case-control studies, and cohort studies that investigated the effects of suvorexant with or without ramelteon on delirium in adult hospitalized patients. The primary outcome was the incidence of delirium. Two randomized controlled trials, 7 cohort studies and 2 case-control studies involving 2594 patients were included in this meta-analysis. The results showed that both suvorexant alone (odds ratio (OR) = 0.30, 95% confidence interval (CI): 0.14-0.65, P = 0.002) and suvorexant with ramelteon (OR = 0.39, 95% CI 0.23-0.65, P = 0.0003) reduced the incidence of delirium in adult hospitalized patients. Six studies involved the use of benzodiazepines; subgroup analysis performed separately in the suvorexant alone and suvorexant with ramelteon groups indicated that when benzodiazepine was administered, suvorexant with ramelteon was effective at reducing the incidence of delirium (OR = 0.53, 95% CI 0.37-0.74, P = 0.0002), but no significant difference was observed for suvorexant alone (OR = 0.40, 95% CI 0.11-1.53, P = 0.18). The current literature thus supports the effectiveness of suvorexant with or without ramelteon for delirium prevention, although suvorexant alone failed to significantly reduce the incidence of delirium when benzodiazepine was administered. The present study was limited by the significant heterogeneity among the included studies, and caution should be exercised when interpreting the results. This study was registered in the PROSPERO database (CRD4202017964).

Melatonin, Ramelteon, Suvorexant, and Dexmedetomidine to Promote Sleep and Prevent Delirium in Critically Ill Patients: A Narrative Review With Practical Applications

Sleep plays an important role in the recovery of critically ill patients. However, patients in the intensive care unit (ICU) often suffer sleep disturbances and abnormal circadian rhythms, which may increase delirium and lengthen ICU stay. Nonpharmacologic strategies for preventing and treating sleep disturbances and delirium, such as overnight eye masks and ear plugs, are usually employed first, given the lack of adverse effects. However, a multimodal approach to care including pharmacotherapy may be necessary. Despite the limited available data supporting their use, medications such as melatonin, ramelteon, suvorexant, and dexmedetomidine may promote sleep and improve a variety of patient-centric outcomes such as delirium. This narrative review focuses on these nonbenzodiazepine agents used for sleep in the ICU. Practical application of each of these agents is described for when providers choose to utilize one of these pharmacotherapies to promote sleep or prevent delirium.

Suvorexant for the prevention of delirium: A meta-analysis

BACKGROUND

Delirium is a frequently encountered complication, which is associated with increased mortality. Suvorexant, an approved agent for the treatment of insomnia, is recently suggested to be also effective for prevention of delirium by some authors. However, a consensus has yet to be reached. The goal of this study was to perform a meta-analysis to overall estimate the effectiveness of suvorexant in preventing delirium and its related consequences.

METHODS

Eligible studies were identified by searching online databases of PubMed, EMBASE, and Cochrane Library. The pooled OR was calculated for binary outcomes (e.g., the incidence of delirium, mortality, or adverse events), while standardized mean difference (SMD) were expressed for continuous outcomes (e.g., time to delirium onset, length of stay in hospital and ICU, time on ventilation).

RESULTS

Seven studies which comprised 402 suvorexant treatment patients and 487 patients with control treatment were included in this meta-analysis. Overall, pooled analysis indicated the incidence of delirium could be significantly reduced (OR, 0.30; P < .001) and time to delirium onset was significantly lengthened (SMD, 0.44; P = .006) in patients undergoing suvorexant treatment compared with controls. Suvorexant had no beneficial effects on the secondary outcomes [length of stay in hospital (SMD, -0.65; P = .161) and ICU (SMD, 0.34; P = .297), time on ventilation (SMD, 1.09; P = .318), drug-related adverse events (OR, drug-related adverse events (OR, 1.66; P = .319) and mortality (OR, 2.21; P = .261)]. Subgroup analysis also confirmed the benefit of suvorexant on the development of delirium, which was significant in any subgroup.

CONCLUSION

Suvorexant should be recommended for the prevention of delirium in clinic.

The role of suvorexant in the prevention of delirium during acute hospitalization: A systematic review

PURPOSE

To assess the efficacy and safety of suvorexant for the prevention of delirium during acute hospitalization.

MATERIALS AND METHODS

Pubmed (1946 to December 2019) and Embase (1947 to December 2019) were queried using the search term combination: delirium, confusion, cognitive defect, encephalopathy, critically ill patient, critical illness, or hospitalization and suvorexant or orexin receptor antagonist. Studies analyzed for relevance evaluated clinical outcomes of patients treated with suvorexant for prevention of delirium. Studies appropriate to the objective were evaluated, including two randomized controlled trials and four retrospective studies.

RESULTS

In acutely hospitalized patients, treatment with suvorexant 15 to 20 mg alone or in combination with ramelteon resulted in a reduction in development of delirium, time until delirium onset, and length of hospital stay. When assessed, suvorexant was well tolerated and adverse effects were no worse than placebo.

CONCLUSION

Based on the reviewed literature, suvorexant has shown positive outcomes in the prevention of delirium during an acute hospitalization. Larger trials comparing the efficacy of suvorexant to other sleep modulating options are necessary to further delineate its role for the prevention of delirium.

Considerations and Current Trends in the Management of the Geriatric Patient on a Consultation-Liaison Service

PURPOSE OF REVIEW

To provide consultation-liaison psychiatrists with an updated resource that can assist in the treatment and management of geriatric patients.

RECENT FINDINGS

The current available literature has not shown any differences in efficacy between haloperidol and second-generation antipsychotics in patients with delirium. When considering relative advantages of forms of antipsychotic administration, there is no support for a superior safety profile of oral compared to intramuscular or intravenous administration. A recent meta-analysis of four randomized controlled trials concluded that when melatonin was administered to older age patients on medical wards, it significantly prevented the incidence of delirium when compared with the control group. While suvorexant administered nightly to elderly patients in acute care settings may lower the incidence of delirium, larger studies are needed to confirm this finding. Despite the black box warning of increased mortality risk in older patients with dementia, antipsychotics may be used with caution by the consultation-liaison (CL) psychiatrist to treat the neuropsychologic symptoms of dementia including hallucinations and psychosis in the hospital setting. While antidepressant studies have focused primarily on citalopram and escitalopram in the treatment of agitation in the setting of dementia, these two medications have not been adequately compared directly to other SSRIs for this condition. It is therefore not clear whether citalopram and escitalopram are more efficacious in treating agitation in the setting of dementia when compared to other SSRIs. While the evidence supporting trazodone's use is limited, it is generally well tolerated and is an option as a PRN for irritability and agitation in patients with Alzheimer's and mixed dementia. While there is some evidence to support the use of acetylcholinesterase inhibitors for treating cognitive impairments and hallucinations in Lewy body dementia, the usefulness of these agents in other forms of dementia is not well studied, and those studies did not show any benefit in the management of acute agitation. It is important to note that memantine can cause or exacerbate agitation and may be the cause of behavioral dysregulation. There is no evidence to support the routine use of benzodiazepines for behavioral improvement in patients with dementia. Escitalopram and citalopram do have a unique pharmacokinetic properties in the sense that they have been found to have 50-56% plasma protein binding, compared to sertraline, fluoxetine, and paroxetine (95% or more). Pooled analyses suggest that antidepressants are more effective than placebo in reducing the symptoms of post-stroke depression. SSRIs are considered first-line antidepressants in stroke patients, who are often elderly with underlying cardiovascular problems. Although treatment with SSRIs is recommended for post-stroke depression, there are no studies providing conclusive data on the superiority of a specific drug. Older age is associated with a better outcome from ECT, with remission rates of approximately 73% to 90% in patients over 65 years. ECT is the treatment of choice for patients with psychotic depression, and elderly patients with psychotic depression have been shown to have a higher remission rate and faster time to response than depressed patients without psychotic symptoms. With the average life expectancy increase, it is projected that 19 million people will reach the age of 85 or higher, an increase from 5.5 million in 2010. With an increasing older population, psychiatric consultation in the management of geriatric patients is becoming more necessary. Psychiatrists must be aware of the unique considerations in elderly patients. In this article, we provide evidence-based guidance to the CL psychiatrist on major issues relating to the older age patient, highlighting recent trends in treatment. First, we provide background on the evaluation of the medically hospitalized geriatric patient. As rates of medical and psychiatric illnesses increase with advancing age, elderly patients are more likely to be taking a higher number of medications as compared to younger patients, and physicians must pay special attention to polypharmacy, including side effects and drug interactions in this group. Next, we focus on the diagnosis, management, and unique needs of the geriatric patient presenting with common clinical syndromes of delirium, dementia, and depression. Delirium and dementia are among the most common causes of cognitive impairment in clinical settings yet are often either unrecognized or misdiagnosed as they may have similar signs and symptoms. In addition, depression is prevalent in older adults, especially in those with comorbid medical illness. Depression can be fatal as the rates of suicide are higher in later life than in any other age group. Consultation can improve the management of elderly patients and prevent unnecessary nursing home placement.

Effects of suvorexant on sleep apnea in patients with heart failure: A protocol of crossover pilot trial

BACKGROUND

Suvorexant, an orexin receptor antagonist, is known as a safe and effective sleep medication. Many patients with heart failure (HF) have sleep-disordered breathing (SDB) and are short sleepers, and it is unknown whether suvorexant is effective in HF patients and can improve insomnia safely. The aim of this study is to examine the effect of suvorexant on SDB in patients with HF.

METHODS

The Heart Failure with Insomnia and Suvorexant trial of Juntendo University Hospital and Juntendo Shizuoka Hospital (J-FLAVOR trial) is a multicenter trial with a randomized double crossover design. We will enroll a total of 30 HF patients treated in the Juntendo University Hospital and Juntendo Shizuoka Hospital. Eligible patients will undergo portable sleep monitoring twice with or without oral administration of suvorexant in a randomly assigned order. Before the study night, patients in the suvorexant first group will receive suvorexant for 4 consecutive days. There are at least 3 wash-out days between the study nights with and without suvorexant. Primary outcome measures of the non-inferiority trial of suvorexant include the apnea-hypopnea index and the severity of SDB, and the results will be compared between the study nights with and without suvorexant.

CONCLUSION

The present study can determine whether suvorexant can be used in HF patients without affecting their SDB. This is a pilot study to primarily assess whether suvorexant affects the severity of SDB in patients with HF. Therefore, further study is warranted to investigate whether suvorexant alters short- and long-term clinical outcomes by providing longer and better sleep in patients with HF.