Postoperative delirium after pharyngolaryngectomy with esophagectomy: a role for ramelteon and suvorexant

Suvorexant for Reduction of Delirium in Older Adults After Hospitalization: A Randomized Clinical Trial

Importance

Delirium is common among older hospitalized adults. In addition to presenting immediate management issues, delirium can increase the long-term risk of dementia, institutionalization, and mortality. Delirium is associated with disrupted sleep, and prior studies suggest that some specific sleep-promoting agents may reduce delirium.

Objective

To evaluate the orexin receptor antagonist suvorexant for reducing delirium in older adults at high risk for delirium after hospitalization.

Design, Setting, and Participants

This double-blind, placebo-controlled, phase 3 randomized clinical trial was conducted at 50 hospitals in Japan between October 22, 2020, and December 23, 2022. The study population included Japanese adults aged 65 to 90 years who were at high risk for delirium (mild cognitive impairment or mild dementia, history of delirium at prior hospitalization, or both) and had been hospitalized for acute disease or elective surgery. Data analysis was performed between January 23 and March 13, 2023.

Intervention

Participants were randomized 1:1 to suvorexant (15 mg) or placebo taken at bedtime for up to 7 days while in the hospital.

Main Outcomes and Measures

Delirium, the primary end point, was diagnosed according to Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition criteria while participants were hospitalized. The treatment difference in the proportion of participants with delirium was analyzed.

Results

This study included 203 participants: 101 were treated with suvorexant (mean [SD] age, 81.5 [4.5]; years; 52 men [51.5%] and 49 women [48.5%]) and 102 received placebo (mean [SD] age, 82.0 [4.9] years; 45 men [44.1%] and 57 women [55.9%]). There were 17 participants with delirium (16.8%) in the suvorexant group compared with 27 (26.5%) in the placebo group (difference, -8.7% [95% CI, -20.1% to 2.6%]; P = .13). Adverse events were similar between the 2 groups.

Conclusions and Relevance

In this randomized clinical trial of suvorexant in older adults at high risk for delirium after hospitalization, fewer participants taking suvorexant had delirium compared with placebo, but the difference was not statistically significant. Further studies are needed to determine whether suvorexant may be useful for reducing delirium, particularly delirium with a hyperactive component, in this population.

Trial Registration

ClinicalTrials.gov Identifier: NCT04571944.

Incidence of Postoperative Delirium in Cancer Patients After Head and Neck Surgery: A Proportional Meta-analysis

OBJECTIVE

To summarize the incidence of postoperative delirium among cancer patients undergoing head and neck surgery and determine the differential incidence rates among patients undergoing different types of head and neck surgeries.

DATA SOURCES

The databases of PubMed, Cochrane Library, Web of Science, EMBASE, and CINAHL were searched from inception till February 2023. Keywords based on the condition (delirium), context (postoperative), and population (head and neck cancer) were used as search terms.

REVIEW METHODS

The PRISMA and MOOSE reporting guidelines were followed. The Joanna Briggs Institute critical appraisal checklists for cohort studies, case-control studies, and randomized controlled trials were used to evaluate the methodological quality. Data were pooled using a random-effects model, and the incidence with 95% confidence intervals was evaluated using the exact binomial method and Freeman-Tukey double arcsine transformation of proportions. I2 was used to indicate heterogeneity. Predefined subgroup analysis and Meta-regression, was performed to identify the factors affecting heterogeneity.

RESULTS

The summary incidence of postoperative delirium was 18.95% [95% confidence interval, 14.36%-24.00%] with between-study heterogeneity (I2  = 95.46%). The incidence of postoperative delirium in patients who underwent free flap reconstruction was 22.13%, which was higher than those of other types of surgeries. Meta-regression revealed that conducted in sample size (P = .007) of the included studies was the factors affecting heterogeneity.

CONCLUSIONS

The evidence on postoperative delirium incidence provided by the current Meta-analysis enables effective treatment planning.

Efficacy of combined use of Suvorexant and Ramelteon in preventing postoperative delirium: a retrospective comparative study

BACKGROUND

Suvorexant and ramelteon have been presented as useful for preventing postoperative delirium. Previous studies reported on the comparison with benzodiazepine hypnotics which have been known for the risk for inducing delirium, but the comparison with patients not taking any hypnotics has not been reported yet. Therefore, we assessed the incidence rates for postoperative delirium comparing cancer patients who received preoperative combined administration with suvorexant and ramelteon and those not taking any hypnotics.

METHODS

Among 110 cancer patients who underwent surgeries at the Division of Hepato-Biliary-Pancreatic Surgery at the Shizuoka Cancer Center between April 1, 2017 and June 30, 2020, 50 patients who received combined administration with suvorexant and ramelteon from 7 days prior to their surgeries and 60 patients who did not take any hypnotics including suvorexant and ramelteon were classified. They were retrospectively observed during the 7 days from their surgeries onward to compare the cumulative incidence rates for postoperative delirium.

RESULTS

The cumulative incidence rate for postoperative delirium during the 7 days in the combined-administration group was 14.0% (7/50), while that for the no-hypnotic group was 36.7% (22/60), which proved that the incidence rate for the former was significantly low (OR: 0.28, 95%CI: 0.11-0.73, P = 0.009).

CONCLUSIONS

The present study suggests that the preventive combined administration with suvorexant and ramelteon starting from the preoperative period for cancer patients can be effective in lowering the incidence rate for postoperative delirium.

TRIAL REGISTRATION

Retrospectively registered.

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.

Effect of pharmacist-led intervention protocol on preventing postoperative delirium after elective cardiovascular surgery

Postoperative delirium (PD) is an acute brain dysfunction, with a particularly high incidence after cardiovascular surgery. Pharmacist-led interventions show limited evidence in attenuating PD in cardiovascular surgery. In this retrospective cohort study, we aimed to clarify the risk factors of PD for cardiovascular surgery focused on pharmacotherapy and elucidate the effect of pharmacist-led intervention on the PD attenuation rate based on protocol-based pharmaceutical management (PBPM). This study included 142 adult patients who underwent elective valve replacement or valvuloplasty. The risk factors for PD were investigated using multivariate logistic regression analysis. Taking risk factors into consideration, a protocol was developed to discontinue benzodiazepines prescriptions by ward pharmacists, and replace with ramelteon and suvorexant if all the following factors apply: 1) number of medications ≥ 6 drugs, 2) number of doses to take ≥ 4 times, and 3) regular use of benzodiazepines or insomnia. Subsequently, the PD rate was compared during a period of two years and 6 months between the pre-PBPM (n = 39) and post-PBPM (n = 62). The PD rate for elective valve replacement or valvuloplasty was 25% (35/142). The adjusted odds ratio for polypharmacy was 3.3 (95% confidence interval: 1.2-8.9, p = 0.016), suggesting that preoperative risk assessment may be essential for patients with polypharmacy. The PD rate significantly decreased to 13% (8/62) in the post-PBPM group compared with 33% (13/39) in the pre-PBPM group (p = 0.014). There was a significant decrease in benzodiazepines use in post-PBPM compared with pre-PBPM (p = 0.026); however, the rate of ramelteon and orexin receptor antagonists use increased by PBPM introduction (p < 0.001). Although the present PBPM still requires further modification, it is simple and potentially useful for pharmacists to assess the risk of patients undergoing any elective cardiovascular surgery.

A multi-centre, double-blind, randomized, placebo-controlled trial to evaluate the effectiveness and safety of ramelteon for the prevention of postoperative delirium in elderly cancer patients: a study protocol for JORTC-PON2/J-SUPPORT2103/NCCH2103

Postoperative delirium is an important issue in cancer patients, affecting surgical outcomes and the quality of life. Ramelteon is a melatonin receptor agonist with high affinity for MT1 and MT2 receptors. Clinical trials and observational studies in Japan, including in surgical cancer patients, have shown efficacy of ramelteon in delirium prevention, with no serious safety concerns. However, clinical trials from the USA have reported conflicting results. A Japanese phase II study investigated the efficacy and safety of ramelteon for delirium prevention following gastrectomy in patients aged ≥75 years, with findings suggesting the feasibility of a phase III trial. The aim of this multi-centre, double-blind, randomized placebo-controlled phase III trial is to evaluate the effectiveness and safety of oral ramelteon for postoperative delirium prevention in cancer patients aged ≥65 years as advanced medical care. The trial protocol is described here.

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.

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).

Significant decrease in delirium referrals after changing hypnotic from benzodiazepine to suvorexant

BACKGROUND

The use of benzodiazepines (BZDs) causes delirium, especially in elderly people. For this reason, suvorexant has been recommended as the first-line hypnotic in elderly patients. The aim of this study was to determine whether the first-line use of suvorexant, instead of BZDs, decreases referrals for delirium in elderly patients.

METHODS

Since May 2016 at Nagoya Ekisaikai Hospital, suvorexant has been recommended as the first-line hypnotic instead of BZDs. In May 2017, suvorexant was adopted as the first-line hypnotic. The number of delirium cases referred to psychiatry was compared among three consecutive periods: period A (May 2015-April 2016), during which BZDs were mainly used for insomnia; period B (May 2016-April 2017), during which the use of suvorexant was recommended instead of BZDs; and period C (May 2017-April 2018), during which suvorexant was principally adopted as the first-line hypnotic for insomnia. Potential confounding factors that may affect the development of delirium were also examined during the three periods.

RESULTS

The number of delirium referral cases in elderly patients in each period decreased, from 133 in period A to 86 in period B and 53 in period C. The rate of delirium referral cases decreased significantly every year (P = 9.02 × 10^-10 ). Almost no significant confounding factors other than hypnotics were detected during the three periods.

CONCLUSION

The referrals for delirium in elderly patients decreased significantly after the hypnotic was changed from BZDs to suvorexant.

Preventative effects of ramelteon against postoperative delirium after elective liver resection

Background

Postoperative delirium was reported to be associated with increased postoperative mortality after liver resection. Therefore, it is crucial to prevent postoperative delirium in such cases. Ramelteon, an agonist of melatonin receptor has been suggested to be useful for preventing delirium. The aim of this study was to examine whether ramelteon is effective at preventing delirium after elective liver resection.

Methods

The cases of patients who underwent liver resection at Nara Medical University (Nara, Japan) between January 2014 and August 2018 were analyzed. During the period from January 2017 to August 2018, ramelteon was prospectively administered to patients who underwent liver resection [8 mg/day on the day before surgery and on postoperative days 1 to 3] (ramelteon group), whereas ramelteon was not administered during the period from January 2014 to December 2016 (control group). The perioperative outcomes of the two groups were compared.

Results

There were 120 patients in the ramelteon group and 186 patients in the control group. No significant intergroup differences in background factors, including age, gender, and preoperative serological laboratory data, were detected. The incidence of postoperative delirium was significantly lower in the ramelteon group (5.8% vs. 15.1%, P = 0.035). Multivariate analysis revealed that being aged ≥75 (P = 0.002), being male (P = 0.020), cardiovascular disease (P = 0.023), blood loss ≥1000ml (P = 0.001) and the absence of ramelteon treatment (P = 0.046) were independent risk factors for postoperative delirium.

Conclusion

The administration of ramelteon might reduce the risk of postoperative delirium after elective liver resection.

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.

Ramelteon for Prevention of Postoperative Delirium: A Randomized Controlled Trial in Patients Undergoing Elective Pulmonary Thromboendarterectomy

OBJECTIVES

To assess the efficacy of ramelteon in preventing delirium, an acute neuropsychiatric condition associated with increased morbidity and mortality, in the perioperative, ICU setting.

DESIGN

Parallel-arm, randomized, double-blinded, placebo-controlled trial.

SETTING

Academic medical center in La Jolla, California.

PATIENTS

Patients greater than or equal to 18 years undergoing elective pulmonary thromboendarterectomy.

INTERVENTIONS

Ramelteon 8 mg or matching placebo starting the night prior to surgery and for a maximum of six nights while in the ICU.

MEASUREMENTS AND MAIN RESULTS

Incident delirium was measured twice daily using the Confusion Assessment Method-ICU. The safety outcome was coma-free days assessed by the Richmond Agitation-Sedation Scale. One-hundred twenty participants were enrolled and analysis completed in 117. Delirium occurred in 22 of 58 patients allocated to placebo versus 19 of 59 allocated to ramelteon (relative risk, 0.8; 95% CI, 0.5-1.4; p = 0.516). Delirium duration, as assessed by the number of delirium-free days was also similar in both groups (placebo median 2 d [interquartile range, 2-3 d] vs ramelteon 3 d [2-5 d]; p = 0.181). Coma-free days was also similar between groups (placebo median 2 d [interquartile range, 1-3 d] vs ramelteon 3 d [2-4 d]; p = 0.210). We found no difference in ICU length of stay (median 4 d [interquartile range, 3-5 d] vs 4 d [3-6 d]; p = 0.349), or in-hospital mortality (four vs three deaths; relative risk ratio, 0.7; 95% CI, 0.2-3.2; p = 0.717), all placebo versus ramelteon, respectively.

CONCLUSIONS

Ramelteon 8 mg did not prevent postoperative delirium in patients admitted for elective cardiac surgery.

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.

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.

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

BACKGROUND

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Preventive Effect of Suvorexant for Postoperative Delirium after Coronary Artery Bypass Grafting

OBJECTIVE

Suvorexant is an orexin receptor antagonist and is effective in inducing sleep. We hypothesized that Suvorexant would reduce the incidence of postoperative delirium (POD) after coronary artery bypass grafting (CABG).

METHODS

We reviewed 88 patients (12 women, mean age: 69.3 ± 2.5 years) who were undergone CABG alone. Patients were divided into two groups; patients received Suvorexant (S group, n = 36), patients not received Suvorexant (N group, n = 52), and the following data were analyzed and compared between two groups.

RESULTS

Intensive Care Unit Delirium Screening Checklist Score was significantly lower in S group compared with N group (N:S = 2.0 ± 1.7:0.8 ± 1.0, p = 0.0003). Although POD was present in 11 of 52 patients (21.2%) in N group, one patient (2.8%) developed in S group (p = 0.008). In S group, both intensive care unit stay (N:S = median 6:5 days, p = 0.001) and hospital stay (N:S = median 23:20 days, p = 0.035) were significantly shorter than in N group.

CONCLUSIONS

Suvorexant might reduce incidence of POD in patients undergone CABG.

Preoperative STOP-BANG Scores and Postoperative Delirium and Coma in Thoracic Surgery Patients

BACKGROUND

Obstructive sleep apnea (OSA) is associated with higher rates of postoperative delirium. The relationship between preoperative OSA risk and postoperative delirium and coma in thoracic surgery patients hospitalized in the intensive care unit (ICU) is not well understood. This study tests the hypothesis that thoracic surgery patients hospitalized in ICU with a higher preoperative risk for OSA are more likely to develop postoperative delirium and coma, resulting in longer hospital stays.

METHODS

Preoperative OSA risk was measured using the STOP-BANG questionnaire. STOP-BANG scores of greater than or equal to 3 were defined as intermediate-high risk for OSA; 128 patients who underwent major thoracic surgery completed the STOP-BANG questionnaire preoperatively. The Richmond Agitation and Sedation Scale was used to assess level of consciousness. The Confusion Assessment Method for the ICU was used to assess for delirium. Linear regression was used to assess the relationship between risk of OSA and outcome measures. Results were adjusted for age, sex, body mass index, Charlson Comorbidity Index, instrumental activities of daily living, and surgery type.

RESULTS

A total of 96 of 128 patients (76%) were in the intermediate-high-risk OSA group. Adjusted analyses showed that the intermediate-high-risk OSA group had a longer duration of postoperative ICU delirium and coma compared with the low-risk OSA group (1.4 ± 1.3 days versus 0.9 ± 1.4 days; P = 0.04). Total number of hospital days was not significantly different.

CONCLUSIONS

Higher preoperative risk for OSA in thoracic surgery patients was associated with a longer duration of postoperative delirium and coma.

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

BACKGROUND

Benzodiazepine use is a risk factor for the development of delirium in adult intensive care unit (ICU) patients. Suvorexant is an alternative to benzodiazepines to induce sleep, but the incidence of delirium in critically ill patients is unknown. We undertook this retrospective study to investigate the incidence of delirium in patients who receive suvorexant in the ICU.

METHODS

This retrospective cohort study was conducted in a closed 12-bed ICU at a tertiary teaching hospital. Patients admitted to the ICU for 72 h or longer between January and June 2015 were evaluated for delirium using the Confusion Assessment Method for the Intensive Care Unit tool. We evaluated the incidence of delirium in patients who received suvorexant and those who did not. To adjust for confounding factors, multivariable logistic regression analysis was conducted.

RESULTS

Study subjects included 118 patients, with a median age of 72 years and a median Acute Physiology and Chronic Health Evaluation II score of 18 points. Eighty-two patients (69.5%) were admitted after cardiovascular surgery. In the suvorexant group, there were fewer post-cardiovascular surgical patients and more medical patients. The duration of mechanical ventilation during ICU stay was longer in the suvorexant group, and sedatives and sleep inducers other than suvorexant were used more frequently in the suvorexant group. The incidence of delirium was 43.8% in the suvorexant group and 58.8% in the non-suvorexant group (P = 0.149). After adjustment for risk factors using multivariable logistic regression analysis, suvorexant was associated with a lower incidence of delirium (odds ratio = 0.23, 95% confidence interval: 0.07-0.73; P = 0.012).

CONCLUSIONS

Suvorexant was associated with decreased odds of transitioning to delirium in critically ill patients. The use of suvorexant may lower the incidence of delirium in ICU patients. Future prospective studies are warranted.

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

Background

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

Objective

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

Methods

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

Results

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

Conclusion

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