Cholinergic deficiency hypothesis in delirium: a synthesis of current evidence

Duration of Agitation, Fluctuations of Consciousness, and Associations with Outcome in Patients with Subarachnoid Hemorrhage

BACKGROUND

Agitation is common after subarachnoid hemorrhage (SAH) and may be independently associated with outcomes. We sought to determine whether the duration of agitation and fluctuating consciousness were also associated with outcomes in patients with SAH.

METHODS

We identified all patients with positive Richmond Agitation Sedation Scale (RASS) scores from a prospective observational cohort of patients with SAH from 2011 to 2015. Total duration of agitation was extrapolated for each patient using available RASS scores, and 24-h mean and standard deviation (SD) of RASS scores were calculated for each patient. We also calculated each patient's duration of substantial fluctuation of consciousness, defined as the number of days with 24-h RASS SD > 1. Patients were stratified by 3-month outcome using the modified Rankin scale, and associations with outcome were assessed via logistic regression.

RESULTS

There were 98 patients with at least one positive RASS score, with median total duration of agitation 8 h (interquartile range [IQR] 4-18), and median duration of substantially fluctuating consciousness 2 days (IQR 1-3). Unfavorable 3-month outcome was significantly associated with a longer duration of fluctuating consciousness (odds ratio [OR] per day, 1.51; 95% confidence interval [CI], 1.04-2.20; p = 0.031), but a briefer duration of agitation (OR per hour, 0.94; 95% CI, 0.89-0.99; p = 0.031).

CONCLUSION

Though a longer duration of fluctuating consciousness was associated with worse outcomes in our cohort, total duration of agitation was not, and may have had the opposite effect. Our findings should therefore challenge the intensity with which agitation is often treated in SAH patients.

[Drug-induced delirium in elderly and senile patients]

Drug-induced delirium is an urgent challenge of modern healthcare, especially in elderly patients, due to the widespread prevalence, associated complications, longer hospitalization period, higher mortality rate. The exact pathogenesis of delirium is unknown, however, a number of studies suggest that it is based on neurotransmitter dysfunction. Thus, drugs that affect the metabolism of these neurotransmitters can lead to the onset of delirium. The Delirium Drug Scale (DDS) and the Anticholinergic Burden scale (ACB) are used to assess the risk of delirium. For patients with an increased risk of delirium, it is recommended to avoid prescribing benzodiazepines, use with caution opiates, dihydropyridines and antagonists of H1-histamine receptors. Non-pharmacological methods are recommended as a first-line treatment of delirium (behavioral approaches, placing the patient in specially equipped delirious rooms, etc.). If non-pharmacological methods have shown to be ineffective or the patient's behavior represents a danger to the life and health of himself and / or others, it is possible to administer antipsychotic drugs.

Delirium Induced by Quetiapine and the Potential Role of Norquetiapine

Quetiapine in an atypical antipsychotic drug that is frequently used for delirium and behavioral and psychological symptoms in dementia. However, its potential anticholinergic effects, mediated primarily through its metabolite norquetiapine, could present as counterproductive adverse effects in these situations. There is little data published discussing this potential negative impact on quetiapine’s safety and tolerability, especially in the elderly. Here, we present what is, to our knowledge, the first published case report of delirium apparently induced by low-dose quetiapine, in a 95-year-old patient with no prior history of mental illness, and the potential role of its metabolite norquetiapine.

State of the clinical science of perioperative brain health: report from the American Society of Anesthesiologists Brain Health Initiative Summit 2018

Cognitive recovery after anaesthesia and surgery is a concern for older adults, their families, and caregivers. Reports of patients who were 'never the same' prompted a scientific inquiry into the nature of what patients have experienced. In June 2018, the ASA Brain Health Initiative held a summit to discuss the state of the science on perioperative cognition, and to create an implementation plan for patients and providers leveraging the current evidence. This group included representatives from the AARP (formerly the American Association of Retired Persons), American College of Surgeons, American Heart Association, and Alzheimer's Association Perioperative Cognition and Delirium Professional Interest Area. This paper summarises the state of the relevant clinical science, including risk factors, identification and diagnosis, prognosis, disparities, outcomes, and treatment of perioperative neurocognitive disorders. Finally, we discuss gaps in current knowledge with suggestions for future directions and opportunities for clinical and translational projects.

Impact of postoperative dexmedetomidine infusion on incidence of delirium in elderly patients undergoing major elective noncardiac surgery: a randomized clinical trial

PURPOSE

Postoperative delirium is a serious and common complication, it occurs in 13-50% of elderly patients after major surgery, and presages adverse outcomes. Emerging literature suggests that dexmedetomidine sedation in critical care units (intensive care unit) is associated with reduced incidence of delirium. However, few studies have investigated whether postoperative continuous infusion of dexmedetomidine could safely decrease the incidence of delirium in elderly patients admitted to general surgical wards after noncardiac surgery.

PATIENTS AND METHODS

This double-blind, randomized, placebo-controlled trial was conducted in patients aged 65 years or older undergoing major elective noncardiac surgery without a planned ICU stay. Eligible patients were randomly assigned to receive either dexmedetomidine (0.1 μg/kg/h) or placebo (0.9% normal saline) immediately after surgery though patient-controlled intravenous analgesia device. The primary outcome was the incidence of delirium during the first 5 postoperative days. Secondary outcomes included postoperative subjective pain scores and subjective sleep quality. The study dates were from January 2018 to January 2019.

RESULTS

A total of 557 patients were randomly assigned to receive either dexmedetomidine (n=281) or placebo (n=276). The incidence of postoperative delirium had no difference between the dexmedetomidine and placebo groups (11.7% [33 of 281] vs 13.8% [38 of 276], P=0.47). Compared with placebo group, patients in dexmedetomidine group reported significant lower numerical rating score pain scores at 3, 12, 24, and 48 hrs after surgery (all P<0.05) and significant improved Richards Campbell Sleep Questionnaire results during the first 3 postoperative days (all P<0.0001). Dexmedetomidine-related adverse events were similar between the two groups.

CONCLUSION

Postoperative continuous infusion of dexmedetomidine did not decrease the incidence of postoperative delirium in elderly patients admitted to general surgical wards after elective noncardiac surgery.

Serum biomarkers of delirium in the elderly: a narrative review

Delirium after surgery and in the intensive care unit (ICU) remains a challenge for patients, families, and caregivers. Over the years, many promising biomarkers have been investigated as potential instruments for risk stratification of delirium. This review aimed to identify and assess the clinical usefulness of candidate serum biomarkers associated with hospital delirium in patients aged 60 years and older. We performed a time-unlimited review of publications indexed in PubMed, Cochrane, Embase, and MEDLINE databases until June 2019 that evaluated baseline and/or longitudinal biomarker measurements in patients suffering from delirium at some point during their hospital stay. A total of 32 studies were included in this review reporting information on 7610 patients. Of these 32 studies, twenty-four studies reported data from surgical patients including four studies in ICU cohorts, five studies reported data from medical patients (1026 patients), and three studies reported data from a mixed cohort (1086 patients), including one study in an ICU cohort. Findings confirm restricted clinical usefulness to predict or diagnose delirium due to limited evidence on which biomarkers can be used and limited availability due to non-routine use.

Clinical Patterns of Continuous and Intermittent Palliative Sedation in Patients With Terminal Cancer: A Descriptive, Observational Study

CONTEXT

Limited information is available regarding the detailed clinical patterns of palliative sedation (PS), that is, the symptom control rate, salvage medication, and the effectiveness of intermittent PS (IPS) versus continuous PS (CPS).

OBJECTIVES

The primary aim was to investigate clinical outcomes of PS in a real clinical setting.

METHODS

Clinical information was prospectively collected for patients who were treated according to a prescribed protocol and assessment tools in a hospice unit affiliated with a tertiary cancer center between September 2015 and March 2017. Data were analyzed retrospectively. Midazolam was used as the first medication for PS, and propofol and phenobarbital were subsequently used as salvage medications. Indications of PS, the depth of sedation, the quality of sleep, and the level of consciousness were assessed.

RESULTS

A total of 306 patients were enrolled, 89 of whom (29.1%) received PS. No difference in survival time was found between patients with and without PS (median survival, 34.0 vs 25.0 days, P = 0.109). Delirium was the most common indication of PS. The symptoms of 73 (82.0%) of 89 patients with PS were relieved with midazolam. Twelve (75.0%) of 16 midazolam-failure patients responded to propofol, five of whom (31%) exhibited respiratory depression. Of the 89 patients receiving PS, 61 (68.5%) received IPS and 28 patients (31.5%) received CPS. The median survival times from PS initiation to death were six days in the IPS group and one day in the CPS group (P < 0.001). Interestingly, consciousness levels were significantly improved after IPS in the delirium group compared with those in the other group (41.7% vs 16.7%, P = 0.002).

CONCLUSION

The refractory symptoms of end-of-life patients with cancer can ultimately be relieved with various medications for PS. IPS may improve the consciousness level of patients with delirium.

Association of Delirium Response and Safety of Pharmacological Interventions for the Management and Prevention of Delirium: A Network Meta-analysis

IMPORTANCE

Although several pharmacological interventions for delirium have been investigated, their overall benefit and safety remain unclear.

OBJECTIVE

To evaluate evidence regarding pharmacological interventions for delirium treatment and prevention.

DATA SOURCES

PubMed, Embase, ProQuest, ScienceDirect, Cochrane Central, Web of Science, ClinicalKey, and ClinicalTrials.gov from inception to May 17, 2018.

STUDY SELECTION

Randomized clinical trials (RCTs) examining pharmacological interventions for delirium treatment and prevention.

DATA EXTRACTION AND SYNTHESIS

To extract data according to a predetermined list of interests, the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines were applied, and all meta-analytic procedures were conducted using a random-effects model.

MAIN OUTCOMES AND MEASURES

The primary outcomes were treatment response in patients with delirium and the incidence of delirium in patients at risk of delirium.

RESULTS

A total of 58 RCTs were included, in which 20 RCTs with 1435 participants (mean age, 63.5 years; 65.1% male) compared the outcomes of treatment and 38 RCTs with 8168 participants (mean age, 70.2 years; 53.4% male) examined the prevention of delirium. A network meta-analysis demonstrated that haloperidol plus lorazepam provided the best response rate for delirium treatment (odds ratio [OR], 28.13; 95% CI, 2.38-333.08) compared with placebo/control. For delirium prevention, the ramelteon, olanzapine, risperidone, and dexmedetomidine hydrochloride groups had significantly lower delirium occurrence rates than placebo/control (OR, 0.07; 95% CI, 0.01-0.66 for ramelteon; OR, 0.25; 95% CI, 0.09-0.69 for olanzapine; OR, 0.27; 95% CI, 0.07-0.99 for risperidone; and OR, 0.50; 95% CI, 0.31-0.80 for dexmedetomidine hydrochloride). None of the pharmacological treatments were significantly associated with a higher risk of all-cause mortality compared with placebo/control.

CONCLUSIONS AND RELEVANCE

This network meta-analysis demonstrated that haloperidol plus lorazepam might be the best treatment and ramelteon the best preventive medicine for delirium. None of the pharmacological interventions for treatment or prophylaxis increased the all-cause mortality.

Biomarker Predictors of Delirium in Acutely Ill Patients: A Systematic Review

Delirium is a serious and common disorder that affects up to 80% of acutely ill patients, mainly the aged. In recent years, several studies pointed out possible biomarkers that could be used alone or in combination with other resources in the diagnosis and follow-up of critically ill patients who develop delirium. In this context, a systematic review was conducted to determine the predictive value of several biomarkers in acutely (critically and noncritically) ill adult patients with delirium. Studies that used the confusion assessment method (CAM) and CAM-intensive care unit as the diagnostic method were considered. The most recent search was performed in November 2017. There was no language restriction. Initially, 626 articles were screened and 39 were included in the study. A comprehensive evaluation of the abstracts resulted in the exclusion of 202 studies, leaving 39 articles as potentially relevant. Inflammatory markers, S100β and cortisol, could predict delirium occurrence in a specific subgroup population of critically ill patients.

Interventions for preventing delirium in older people in institutional long-term care

BACKGROUND

Delirium is a common and distressing mental disorder. It is often caused by a combination of stressor events in susceptible people, particularly older people living with frailty and dementia. Adults living in institutional long-term care (LTC) are at particularly high risk of delirium. An episode of delirium increases risks of admission to hospital, development or worsening of dementia and death. Multicomponent interventions can reduce the incidence of delirium by a third in the hospital setting. However, it is currently unclear whether interventions to prevent delirium in LTC are effective. This is an update of a Cochrane Review first published in 2014.

OBJECTIVES

To assess the effectiveness of interventions for preventing delirium in older people in institutional long-term care settings.

SEARCH METHODS

We searched ALOIS (www.medicine.ox.ac.uk/alois), the Cochrane Dementia and Cognitive Improvement Group (CDCIG) 's Specialised Register of dementia trials (dementia.cochrane.org/our-trials-register), to 27 February 2019. The search was sufficiently sensitive to identify all studies relating to delirium. We ran additional separate searches in the Cochrane Central Register of Controlled Trials (CENTRAL), major healthcare databases, trial registers and grey literature sources to ensure that the search was comprehensive.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and cluster-randomised controlled trials (cluster-RCTs) of single and multicomponent, non-pharmacological and pharmacological interventions for preventing delirium in older people (aged 65 years and over) in permanent LTC residence.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Primary outcomes were prevalence, incidence and severity of delirium; and mortality. Secondary outcomes included falls, hospital admissions and other adverse events; cognitive function; new diagnoses of dementia; activities of daily living; quality of life; and cost-related outcomes. We used risk ratios (RRs) as measures of treatment effect for dichotomous outcomes, hazard ratios (HR) for time-to-event outcomes and mean difference (MD) for continuous outcomes. For each outcome, we assessed the overall certainty of the evidence using GRADE methods.

MAIN RESULTS

We included three trials with 3851 participants. All three were cluster-RCTs. Two of the trials were of complex, single-component, non-pharmacological interventions and one trial was a feasibility trial of a complex, multicomponent, non-pharmacological intervention. Risk of bias ratings were mixed across the three trials. Due to the heterogeneous nature of the interventions, we did not combine the results statistically, but produced a narrative summary.It was not possible to determine the effect of a hydration-based intervention on delirium incidence (RR 0.85, 95% confidence interval (CI) 0.18 to 4.00; 1 study, 98 participants; very low-certainty evidence downgraded for risk of bias and very serious imprecision). This study did not assess delirium prevalence, severity or mortality.The introduction of a computerised system to identify medications that may contribute to delirium risk and trigger a medication review was probably associated with a reduction in delirium incidence (12-month HR 0.42, CI 0.34 to 0.51; 1 study, 7311 participant-months; moderate-certainty evidence downgraded for risk of bias) but probably had little or no effect on mortality (HR 0.88, CI 0.66 to 1.17; 1 study, 9412 participant-months; moderate-certainty evidence downgraded for imprecision), hospital admissions (HR 0.89, CI 0.72 to 1.10; 1 study, 7599 participant-months; moderate-certainty evidence downgraded for imprecision) or falls (HR 1.03, CI 0.92 to 1.15; 1 study, 2275 participant-months; low-certainty evidence downgraded for imprecision and risk of bias). Delirium prevalence and severity were not assessed.In the enhanced educational intervention study, aimed at changing practice to address key delirium risk factors, it was not possible to determine the effect of the intervention on delirium incidence (RR 0.62, 95% CI 0.16 to 2.39; 1 study, 137 resident months; very low-certainty evidence downgraded for risk of bias and serious imprecision) or delirium prevalence (RR 0.57, 95% CI 0.15 to 2.19; 1 study, 160 participants; very low-certainty evidence downgraded for risk of bias and serious imprecision). There was probably little or no effect on mortality (RR 0.82, CI 0.50 to 1.34; 1 study, 215 participants; moderate-certainty evidence downgraded for imprecision). The intervention was probably associated with a reduction in hospital admissions (RR 0.67, CI 0.57 to 0.79; 1 study, 494 participants; moderate-certainty evidence downgraded due to indirectness).

AUTHORS' CONCLUSIONS

Our review identified limited evidence on interventions for preventing delirium in older people in LTC. A software-based intervention to identify medications that could contribute to delirium risk and trigger a pharmacist-led medication review, probably reduces incidence of delirium in older people in institutional LTC. This is based on one large RCT in the US and may not be practical in other countries or settings which do not have comparable information technology services available in care homes. In the educational intervention aimed at identifying risk factors for delirium and developing bespoke solutions within care homes, it was not possible to determine the effect of the intervention on delirium incidence, prevalence or mortality. This evidence is based on a small feasibility trial. Our review identified three ongoing trials of multicomponent delirium prevention interventions. We identified no trials of pharmacological agents. Future trials of multicomponent non-pharmacological delirium prevention interventions for older people in LTC are needed to help inform the provision of evidence-based care for this vulnerable group.

Prevention and management of delirium in critically ill adult patients in the intensive care unit: a review based on the 2018 PADIS guidelines

Delirium is an acute, confusional state characterized by altered consciousness and a reduced ability to focus, sustain, or shift attention. It is associated with a number of complex underlying medical conditions and can be difficult to recognize. Many critically ill patients (e.g., up to 80% of patients in the intensive care unit [ICU]) experience delirium due to underlying medical or surgical health problems, recent surgical or other invasive procedures, medications, or various noxious stimuli (e.g., underlying psychological stressors, mechanical ventilation, noise, light, patient care interactions, and drug-induced sleep disruption or deprivation). Delirium is associated with a longer duration of mechanical ventilation and ICU admittance as well as an increased risk of death, disability, and long-term cognitive dysfunction. Therefore, the early recognition of delirium is important and ICU medical staff should devote careful attention to both watching for the occurrence of delirium and its prevention and management. This review presents a brief overview of delirium and an update of the literature with reference to the 2018 Society of Critical Care Medicine Clinical Practice Guidelines for the Prevention and Management of Pain, Agitation/Sedation, Delirium, Immobility, and Sleep Disruption in Adult Patients in the ICU.

Forebrain Cholinergic Signaling Regulates Innate Immune Responses and Inflammation

The brain regulates physiological functions integral to survival. However, the insight into brain neuronal regulation of peripheral immune function and the neuromediator systems and pathways involved remains limited. Here, utilizing selective genetic and pharmacological approaches, we studied the role of forebrain cholinergic signaling in the regulation of peripheral immune function and inflammation. Forebrain-selective genetic ablation of acetylcholine release and vagotomy abolished the suppression of serum TNF by the centrally-acting cholinergic drug galantamine in murine endotoxemia. Selective stimulation of acetylcholine action on the M1 muscarinic acetylcholine receptor (M1 mAChR) by central administration of the positive allosteric modulator benzyl quinolone carboxylic acid (BQCA) suppressed serum TNF (TNFα) levels in murine endotoxemia. This effect was recapitulated by peripheral administration of the compound. BQCA also improved survival in murine endotoxemia and these effects were abolished in M1 mAChR knockout (KO) mice. Selective optogenetic stimulation of basal forebrain cholinergic neurons innervating brain regions with abundant M1 mAChR localization reduced serum TNF in endotoxemic mice. These findings reveal that forebrain cholinergic neurons regulate innate immune responses and inflammation, suggesting the possibility that in diseases associated with cholinergic dysfunction, including Alzheimer's disease this anti-inflammatory regulation can be impaired. These results also suggest novel anti-inflammatory approaches based on targeting forebrain cholinergic signaling in sepsis and other disorders characterized by immune dysregulation.

Understanding Central Nervous System Effects of Deliriant Hallucinogenic Drugs through Experimental Animal Models

Hallucinogenic drugs potently alter human behavior and have a millennia-long history of use for medicinal and religious purposes. Interest is rapidly growing in their potential as CNS modulators and therapeutic agents for brain conditions. Antimuscarinic cholinergic drugs, such as atropine and scopolamine, induce characteristic hyperactivity and dream-like hallucinations and form a separate group of hallucinogens known as "deliriants". Although atropine and scopolamine are relatively well-studied drugs in cholinergic physiology, deliriants represent the least-studied class of hallucinogens in terms of their behavioral and neurological phenotypes. As such, novel approaches and new model organisms are needed to investigate the CNS effects of these compounds. Here, we comprehensively evaluate the preclinical effects of deliriant hallucinogens in various animal models, their mechanisms of action, and potential interplay with other signaling pathways. We also parallel experimental and clinical findings on deliriant agents and outline future directions of translational research in this field.

Delirium in the critically ill patient

Delirium is an acute and transient brain dysfunction that is characterized by disturbances in consciousness, affecting both its content (i.e., attention) and level (i.e., arousal). It affects as many as 50% of those admitted to an intensive care unit (ICU). Once believed to be an inconsequential outcome of critical illness, it is now recognized that delirium is harmful in both the short- and long-term. Despite occurring frequently in critically ill patients, delirium often goes unrecognized. Well-validated delirium screening tools, designed for use in the ICU, should be used to reliably detect delirium. The first step in delirium treatment is to identify and address potentially modifiable risk factors. Multiple trials have shown that benzodiazepines are a risk factor for delirium in a dose-dependent manner. Sedation with nonbenzodiazepine-based strategies are an effective means by which to reduce delirium. Nonpharmacologic strategies such as those which seek to reduce sensory impairment, sleep deprivation, and immobility are effective. Pharmacologic treatment with antipsychotics, though commonly used, is not supported by findings from placebo-controlled trials. Recent data support from multiple trials support the use of the "ABCDEF bundle" as a means by which to reduce delirium.

The relationship between serum cobalamin, folic acid, and homocysteine and the risk of post-cardiac surgery delirium

Purpose: It has been reported that cobalamin and folate deficiency is related to delirium in persons with dementia. We evaluated the association of admission serum levels of cobalamin, folic acid, and homocysteine with the occurrence of acute delirium after coronary artery bypass surgery. Methods: In this prospective cohort study, serum levels of cobalamin, folic acid, and homocysteine were measured for 296 patients upon admission. Delirium was defined by the confusion assessment method for the intensive care unit. Results: Postoperative delirium was detected in 23% (n=68) of patients. Cobalamin deficiency, folate deficiency, and hyperhomocysteinemia were observed in 29% (n=86), 6% (n=18), and 68% (n=200) of patients, respectively. The mean ± SD serum levels of folic acid were 10.77±5.39 ng/mL and 12.86±6.51 ng/mL in delirium and non-delirium patients, respectively (P=0.008). The median (interquartile range [IQR]) serum levels of cobalamin were 280 (216-351) and 247 (195.5-336) in delirium and non-delirium patients, respectively (P=0.09). The median (IQR) serum levels of homocysteine were 18.5 (14.5-22.1) µmol/L and 17.33 (14.2-23.2) µmol/L in delirium and non-delirium patients, respectively (P=0.94). Multivariate regression analysis adjusted by other risk factors indicated that serum homocysteine, folate, and cobalamin levels had no association with the occurrence of delirium. Conclusion: There was no relationship between the preoperative levels of cobalamin, folate, and homocysteine, and acute occurrence of delirium observed after cardiac surgery.

Delirium in medical intensive care units: Incidence, subtypes, risk factors, and outcome

BACKGROUND

Delirium is a frequent yet underdiagnosed neuropsychiatric condition encountered in intensive care units (ICUs). Being both a preventable and potentially reversible process associated with significant morbidity and mortality, understanding risk factors that predispose and precipitate delirium in any given patient are critical in ICUs.

AIMS AND OBJECTIVES

The aim of this study is to evaluate the incidence, motor subtypes, risk factors, and clinical outcome of delirium in the medical ICU.

MATERIALS AND METHODS

We used a prospective study design on a cohort of consecutive medical ICU admissions of a tertiary care teaching hospital. The Confusion Assessment Method-ICU and Richmond Agitation Sedation Scale were used to diagnose and motor subtype delirium, respectively, along with a checklist to assess risk factors.

RESULTS

Of the 280 ICU admissions, 88 (31.4%) developed delirium. Hypoactive delirium was the most common motor subtype (55.7%). The detection rate of delirium was 12.5% (lowest for hypoactive delirium at 2.04%). Age, gender, and years of education did not significantly predict delirium (all P > 0.05). Tobacco use, chronic liver disease, and past episodes of delirium significantly predisposed, while mechanical ventilation, hypoxia, fever, raised levels of bilirubin and creatinine, and benzodiazepine administration significantly precipitated ICU delirium. Delirium was significantly associated with longer ICU stay (t = 4.23, P = 0.000) and 1-month postdischarge mortality (χ ² = 6.867, P = 0.009).

CONCLUSION

Detection of delirium is challenging, especially in ICU patients on mechanical ventilation and hypoactive delirium. Screening and monitoring for predisposing and precipitating risk factors can greatly improve the odds of detection and intervention as ICU delirium is associated with significant morbidity and mortality.

Preventing Postoperative Delirium After Major Noncardiac Thoracic Surgery-A Randomized Clinical Trial

OBJECTIVES

To assess the efficacy of haloperidol in reducing postoperative delirium in individuals undergoing thoracic surgery.

DESIGN

Randomized double-blind placebo-controlled trial.

SETTING

Surgical intensive care unit (ICU) of tertiary care center.

PARTICIPANTS

Individuals undergoing thoracic surgery (N=135).

INTERVENTION

Low-dose intravenous haloperidol (0.5 mg three times daily for a total of 11 doses) administered postoperatively.

MEASUREMENTS

The primary outcome was delirium incidence during hospitalization. Secondary outcomes were time to delirium, delirium duration, delirium severity, and ICU and hospital length of stay. Delirium was assessed using the Confusion Assessment Method for the ICU and delirium severity using the Delirium Rating Scale-Revised.

RESULTS

Sixty-eight participants were randomized to receive haloperidol and 67 placebo. No significant differences were observed between those receiving haloperidol and those receiving placebo in incident delirium (n=15 (22.1%) vs n=19 (28.4%); p = .43), time to delirium (p = .43), delirium duration (median 1 day, interquartile range (IQR) 1-2 days vs median 1 day, IQR 1-2 days; p = .71), delirium severity, ICU length of stay (median 2.2 days, IQR 1-3.3 days vs median 2.3 days, IQR 1-4 days; p = .29), or hospital length of stay (median 10 days, IQR 8-11.5 days vs median 10 days, IQR 8-12 days; p = .41). In the esophagectomy subgroup (n = 84), the haloperidol group was less likely to experience incident delirium (n=10 (23.8%) vs n=17 (40.5%); p = .16). There were no differences in time to delirium (p = .14), delirium duration (median 1 day, IQR 1-2 days vs median 1 day, IQR 1-2 days; p = .71), delirium severity, or hospital length of stay (median 11 days, IQR 10-12 days vs median days 11, IQR 10-15 days; p = .26). ICU length of stay was significantly shorter in the haloperidol group (median 2.8 days, IQR 1.1-3.8 days vs median 3.1 days, IQR 2.1-5.1 days; p = .03). Safety events were comparable between the groups.

CONCLUSION

Low-dose postoperative haloperidol did not reduce delirium in individuals undergoing thoracic surgery but may be efficacious in those undergoing esophagectomy. J Am Geriatr Soc 66:2289-2297, 2018.

Vagus nerve cholinergic circuitry to the liver and the gastrointestinal tract in the neuroimmune communicatome

Improved understanding of neuroimmune communication and the neural regulation of immunity and inflammation has recently led to proposing the concept of the "neuroimmune communicatome." This advance is based on experimental evidence for an organized and brain-integrated reflex-like relationship and dialogue between the nervous and the immune systems. A key circuitry in this communicatome is provided by efferent vagus nerve fibers and cholinergic signaling. Inflammation and metabolic alterations coexist in many disorders affecting the liver and the gastrointestinal (GI) tract, including obesity, metabolic syndrome, fatty liver disease, liver injury, and liver failure, as well as inflammatory bowel disease. Here, we outline mechanistic insights regarding the role of the vagus nerve and cholinergic signaling in the regulation of inflammation linked to metabolic derangements and the pathogenesis of these disorders in preclinical settings. Recent clinical advances using this knowledge in novel therapeutic neuromodulatory approaches within the field of bioelectronic medicine are also briefly summarized.

Debate article: Antipsychotic medications are clinically useful for the treatment of delirium

Prescribing of antipsychotic medications for patients with delirium remains controversial. Concerns exist that these vulnerable and frail patients may be prescribed antipsychotics inappropriately as a substitute for non-pharmacological approaches when identifiable causes are not found or they challenge ward processes. Moreover, recent evidence suggests that antipsychotics may cause more harm than good in the palliative care patient group with delirium. On the other hand, guidelines in the United Kingdom and the Netherlands support prescribing of antipsychotics in certain circumstances, and a large European survey has revealed that antipsychotics tend to be prescribed first line for hyperactive delirium. Never before, therefore, is there a greater need to examine whether indeed these medications are clinically useful for the treatment of delirium. With this in mind, evidence-based arguments for and against prescribing antipsychotics for the treatment of delirium are presented in this debate article. The paper concludes with a moderation piece to help guide clinical practice.

Delirium pathophysiology: An updated hypothesis of the etiology of acute brain failure

BACKGROUND

Delirium is the most common neuropsychiatric syndrome encountered by clinicians dealing with older adults and the medically ill and is best characterized by 5 core domains: cognitive deficits, attentional deficits, circadian rhythm dysregulation, emotional dysregulation, and alteration in psychomotor functioning.

DESIGN

An extensive literature review and consolidation of published data into a novel interpretation of known pathophysiological causes of delirium.

RESULTS

Available data suggest that numerous pathological factors may serve as precipitants for delirium, each having differential effects depending on patient-specific patient physiological characteristics (substrate). On the basis of an extensive literature search, a newly proposed theory, the systems integration failure hypothesis, was developed to bring together the most salient previously described theories, by describing the various contributions from each into a complex web of pathways-highlighting areas of intersection and commonalities and explaining how the variable contribution of these may lead to the development of various cognitive and behavioral dysfunctions characteristic of delirium. The specific cognitive and behavioral manifestations of the specific delirium picture result from a combination of neurotransmitter function and availability, variability in integration and processing of sensory information, motor responses to both external and internal cues, and the degree of breakdown in neuronal network connectivity, hence the term acute brain failure.

CONCLUSIONS

The systems integration failure hypothesis attempts to explain how the various proposed delirium pathophysiologic theories interact with each other, causing various clinically observed delirium phenotypes. A better understanding of the underlying pathophysiology of delirium may eventually assist in designing better prevention and management approaches.

Symptom Expression in Patients with Advanced Cancer Admitted to an Acute Supportive/Palliative Care Unit With and Without Delirium

AIM

The aim of this study was to investigate the relationship between delirium and symptom expression in patients with advanced cancer admitted to an acute supportive/palliative care unit (ASPCU).

METHODS

A consecutive sample of patients with advanced cancer who were admitted to an ASPCU was prospectively assessed for a period of 10 months. The Edmonton Symptom Assessment Scale (ESAS) and the MDAS (Memorial Delirium Assessment Scale) were measured at admission (T0) and after 7 days of palliative care (T7).

RESULTS

Two hundred forty-six patients had complete data regarding MDAS measurements, at either T0 and T7. Of these, 75 (30.5%) and 63 patients (25.6%) had delirium at T0 and after a week of palliative care (T7), with a decrease in the frequency of delirium of 4.9% (from 30.5% to 25.6%); that means that 16% of patients with delirium improved their cognitive status after initiation of palliative care. Intensities of pain, depression, poor well-being, and global ESAS were significantly higher in patients with delirium. Patients who did not have delirium at T0 but developed delirium during admission after 1 week of palliative care had a higher level of symptom expression for pain, weakness, nausea, anxiety, dyspnea, appetite, and consequently global ESAS. Patients who did not develop delirium at any time had a relevant decrease in intensity of all ESAS items after 1 week of palliative care. The decrease of symptom intensity was significant for pain, insomnia, appetite, poor well-being, and global ESAS in patients with delirium either at T0 and T7, although these differences were less relevant than those observed in patients without delirium. In patients with delirium at T0 who improved their cognitive function at T7 (no delirium), significant changes were found in most ESAS items.

CONCLUSION

Symptom expression is amplified in patients with delirium, whereas patients without delirium may be more responsive to palliative treatments with a significant decrease in intensity of ESAS items.

IMPLICATIONS FOR PRACTICE

Symptom expression is amplified in patients with cancer who have delirium, whereas patients without delirium may be more responsive to palliative treatments with a significant decrease in symptom intensity.

Advances in the pharmacotherapeutic management of dementia with Lewy bodies

INTRODUCTION

Dementia with Lewy bodies (DLB) is the second most common type of dementia in people over 65 years of age. Given the complex clinical phenotype, the management of DLB may be challenging, especially considering that there is limited evidence about specific interventions, and there are currently no Food and Drug Administration (FDA)/European Medicines Agency (EMA)-approved medications.

AREAS COVERED

This article provides an overview of the current pharmacotherapy in DLB and gives review to the most recent drug candidates in clinical trials.

EXPERT OPINION

Commonly prescribed drugs are primarily aimed at treating the most troublesome clinical features of DLB. Although these medications provide some benefit to symptoms, there is, unfortunately, a lack of DLB-specific evidence on effective treatments and their off-label use. Indeed, most treatments used come from clinical trials on patients with Alzheimer's disease or Parkinson's disease. Thus, there is an urgent need for randomized clinical trials in DLB patients. Despite several challenges, potential new drugs are in ongoing clinical trials; furthermore, as our understanding of molecular and cellular mechanisms underlying DLB broaden, it is likely that we will identify novel drug targets for the development of better and more effective symptomatic products and disease-modifying therapies.

TIME to think about delirium: improving detection and management on the acute medical unit

Delirium affects 18%–35% patients in the acute hospital setting, yet is often neither detected nor managed appropriately. It is associated with increased risk of falls, longer hospital stay and increased morbidity and mortality rates. It is a frightening and unpleasant experience for both patients and their families. We used quality improvement tools and a multicomponent intervention to promote detection and improve management of delirium on the acute medical unit (AMU). We reviewed whether a delirium screening tool (4AT) had been completed for all patients aged over 65 years admitted to the AMU over 1 week. If delirium was detected, we assessed whether investigation and management was adequate as per national guidance. After baseline data collection, we delivered focused sessions of delirium education for doctors and nursing staff, including training on use of the 4AT tool and the TIME (Triggers, Investigate, Manage, Engage) management bundle. We introduced TIME checklists, an online delirium order set and created a bedside orientation tool. We collected data following the interventions and identified areas for further improvement. Following our first PDSA (Plan, Do, Study, Act) cycle, use of the 4AT screening tool improved from 40% to 61%. Adequate assessment for the causes of and exacerbating factors for delirium increased from 73% to 94% of cases. Use of personal orientation tools improved from 0% to 38%. In summary, a targeted staff education programme and practical aids for the ward have improved the screening and management of delirium on the AMU. This may be improved further through more frequent training sessions to account for regular change-over of junior doctors and through implementing a nursing champion for delirium.

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.

Cholinesterase inhibitors for the treatment of delirium in non-ICU settings

BACKGROUND

Delirium is a common clinical syndrome defined as alterations in attention with an additional disturbance in cognition or perception, which develop over a short period of time and tend to fluctuate during the course of the episode. Delirium is commonly treated in hospitals or community settings and is often associated with multiple adverse outcomes such as increased cost, morbidity, and even mortality. The first-line intervention involves a multicomponent non-pharmacological approach that includes ensuring effective communication and reorientation in addition to providing reassurance or a suitable care environment. There are currently no drugs approved specifically for the treatment of delirium. Clinically, however, various medications are employed to provide symptomatic relief, such as antipsychotic medications and cholinesterase inhibitors, among others.

OBJECTIVES

To evaluate the effectiveness and safety of cholinesterase inhibitors for treating people with established delirium in a non-intensive care unit (ICU) setting.

SEARCH METHODS

We searched ALOIS, which is the Cochrane Dementia and Cognitive Improvement Group's Specialised Register, on 26 October 2017. We also cross-checked the reference lists of included studies to identify any potentially eligible trials.

SELECTION CRITERIA

We included randomised controlled trials, published or unpublished, reported in English or Chinese, which compared cholinesterase inhibitors to placebo or other drugs intended to treat people with established delirium in a non-ICU setting.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by Cochrane. The primary outcomes were duration of delirium, severity of delirium, and adverse events. The secondary outcomes were use of rescue medications, persistent cognitive impairment, length of hospitalisation, institutionalisation, mortality, cost of intervention, leaving the study early, and quality of life. For dichotomous outcomes, we calculated the risk ratio (RR) with 95% confidence intervals (CIs); for continuous outcomes we calculated the mean difference (MD) with 95% CIs. We assessed the quality of evidence using GRADE to generate a 'Summary of findings' table.

MAIN RESULTS

We included one study involving 15 participants from the UK. The included participants were diagnosed with delirium based on the Confusion Assessment Method (CAM) criteria. Eight males and seven females were included, with a mean age of 82.5 years. Seven of the 15 participants had comorbid dementia at baseline. The risk of bias was low in all domains.The study compared rivastigmine with placebo. We did not find any clear differences between the two groups in terms of duration of delirium (MD -3.6, 95% CI -15.6 to 8.4), adverse events (nausea, RR 0.30, 95% CI 0.01 to 6.29), use of rescue medications (RR 0.13, 95% CI 0.01 to 2.1), mortality (RR 0.10, 95% CI 0.01 to 1.56), and leaving the study early (RR 0.88, 95% CI 0.07 to 11.54). Evidence was not available regarding the severity of delirium, persistent cognitive impairment, length of hospitalisation, cost of intervention, or other predefined secondary outcomes.The quality of evidence is low due to the very small sample size.

AUTHORS' CONCLUSIONS

There is insufficient evidence to support or refute the use of cholinesterase inhibitors for the treatment of delirium in non-ICU settings. No clear benefits or harms associated with cholinesterase inhibitors were observed when compared with placebo due to the lack of data. More trials are required.

Acetylcholinesterase Activity Measurement and Clinical Features of Delirium

AIMS

Cholinergic deficiency is commonly implicated in the pathophysiology of delirium. We aimed to investigate the relationship between directly measured serum acetylcholinesterase (AChE) activity and (1) clinical features of delirium and (2) outcomes among older hospital patients with delirium.

METHODS

Hospitalised patients with delirium were recruited, and delirium motor subtype, severity and duration of delirium were measured. Serum AChE activity was measured using a colorimetric assay.

RESULTS

The mean AChE activity for the whole sample was 2.46 μmol/μL/min (standard deviation 1.75). Higher AChE activity was associated with increased likelihood of hypoactive delirium rather than the hyperactive or mixed subtype (odds ratio 1.98, 95% confidence interval 1.10-3.59).

CONCLUSION

Higher AChE activity was associated with hypoactive delirium but did not predict outcomes. Simple enhancement of cholinergic neurotransmission may not be sufficient to treat delirium.

A rare case of REM sleep-related bradyarrhythmia syndrome with concomitant severe hypertension: a case report and a review of literature

Introduction

Rapid eye movement (REM) sleep-related bradyarrhythmia syndrome is characterized by pathological asystoles during the REM sleep phase. It is a rare rhythm disorder, being reported only few times in the literature. Due to non-specific symptoms, REM sleep-related bradyarrhythmia might be often underdiagnosed. Other cardiac diseases associated with pathological sinus arrests must be excluded to establish the correct diagnosis of and appropriate therapy for REM sleep-related bradyarrhythmia. We report a case of this syndrome followed by hypertension and diastolic heart failure.

The case

A 49-year-old male with severe hypertension presented for a cardiologist's consultation. His main complaints were palpitations, fatigue, dyspnoea, and snoring. Polysomnography test revealed a normal sleep structure with episodes of bradycardia and increased parasympathetic activity during phasic events of REM sleep. Heart rate variability Poincare plot analysis demonstrated similar results. REM sleep-related bradyarrhythmia syndrome was diagnosed and patient was treated with dual chamber heart pacemaker implantation.

Discussion

Various components of the autonomic nervous system influence the development of REM sleep-related bradyarrhythmia syndrome. The main factor is likely an increased vagal tone during the phasic REM sleep with the absence of normal compensatory sympathetic activity. Concomitant hypertension in REM sleep-related bradyarrhythmia syndrome is caused by a paradoxically abnormal control of the autonomic nervous system and can be explained through the acetylcholine metabolism pathway. Best suited diagnostic and treatment options for REM sleep-related bradyarrhythmia syndrome are discussed.

Conclusions

Patients with REM sleep-related bradyarrhythmia syndrome often present with indistinct symptoms. Polysomnography is an essential diagnostic test for the differential diagnosis of various nocturnal arrhythmias and sleep disorders. Severe hypertension is a common complication of sleep disorders and requires appropriate treatment of the underlying condition. An implantation of a heart pacemaker is the first-choice treatment for patients with REM sleep-related bradyarrhythmia syndrome.

Antipsychotics for treatment of delirium in hospitalised non-ICU patients

BACKGROUND

Guidelines suggest limited and cautious use of antipsychotics for treatment of delirium where nonpharmacological interventions have failed and symptoms remain distressing or dangerous, or both. It is unclear how well these recommendations are supported by current evidence.

OBJECTIVES

Our primary objective was to assess the efficacy of antipsychotics versus nonantipsychotics or placebo on the duration of delirium in hospitalised adults. Our secondary objectives were to compare the efficacy of: 1) antipsychotics versus nonantipsychotics or placebo on delirium severity and resolution, mortality, hospital length of stay, discharge disposition, health-related quality of life, and adverse effects; and 2) atypical vs. typical antipsychotics for reducing delirium duration, severity, and resolution, hospital mortality and length of stay, discharge disposition, health-related quality of life, and adverse effects.

SEARCH METHODS

We searched MEDLINE, Embase, Cochrane EBM Reviews, CINAHL, Thomson Reuters Web of Science and the Latin American and Caribbean Health Sciences Literature (LILACS) from their respective inception dates until July 2017. We also searched the Database of Abstracts of Reviews of Effects (DARE), Health Technology Assessment Database, Web of Science ISI Proceedings, and other grey literature.

SELECTION CRITERIA

We included randomised and quasi-randomised trials comparing 1) antipsychotics to nonantipsychotics or placebo and 2) typical to atypical antipsychotics for the treatment of delirium in adult hospitalised (but not critically ill) patients.

DATA COLLECTION AND ANALYSIS

We examined titles and abstracts of identified studies to determine eligibility. We extracted data independently in duplicate. Disagreements were settled by further discussion and consensus. We used risk ratios (RR) with 95% confidence intervals (CI) as a measure of treatment effect for dichotomous outcomes, and between-group standardised mean differences (SMD) with 95% CI for continuous outcomes.

MAIN RESULTS

We included nine trials that recruited 727 participants. Four of the nine trials included a comparison of an antipsychotic to a nonantipsychotic drug or placebo and seven included a comparison of a typical to an atypical antipsychotic. The study populations included hospitalised medical, surgical, and palliative patients.No trial reported on duration of delirium. Antipsychotic treatment did not reduce delirium severity compared to nonantipsychotic drugs (standard mean difference (SMD) -1.08, 95% CI -2.55 to 0.39; four studies; 494 participants; very low-quality evidence); nor was there a difference between typical and atypical antipsychotics (SMD -0.17, 95% CI -0.37 to 0.02; seven studies; 542 participants; low-quality evidence). There was no evidence antipsychotics resolved delirium symptoms compared to nonantipsychotic drug regimens (RR 0.95, 95% CI 0.30 to 2.98; three studies; 247 participants; very low-quality evidence); nor was there a difference between typical and atypical antipsychotics (RR 1.10, 95% CI 0.79 to 1.52; five studies; 349 participants; low-quality evidence). The pooled results indicated that antipsychotics did not alter mortality compared to nonantipsychotic regimens (RR 1.29, 95% CI 0.73 to 2.27; three studies; 319 participants; low-quality evidence) nor was there a difference between typical and atypical antipsychotics (RR 1.71, 95% CI 0.82 to 3.35; four studies; 342 participants; low-quality evidence).No trial reported on hospital length of stay, hospital discharge disposition, or health-related quality of life. Adverse event reporting was limited and measured with inconsistent methods; in those reporting events, the number of events were low. No trial reported on physical restraint use, long-term cognitive outcomes, cerebrovascular events, or QTc prolongation (i.e. increased time in the heart's electrical cycle). Only one trial reported on arrhythmias and seizures, with no difference between typical or atypical antipsychotics. We found antipsychotics did not have a higher risk of extrapyramidal symptoms (EPS) compared to nonantipsychotic drugs (RR 1.70, 95% CI 0.04 to 65.57; three studies; 247 participants; very-low quality evidence); pooled results showed no increased risk of EPS with typical antipsychotics compared to atypical antipsychotics (RR 12.16, 95% CI 0.55 to 269.52; two studies; 198 participants; very low-quality evidence).

AUTHORS' CONCLUSIONS

There were no reported data to determine whether antipsychotics altered the duration of delirium, length of hospital stay, discharge disposition, or health-related quality of life as studies did not report on these outcomes. From the poor quality data available, we found antipsychotics did not reduce delirium severity, resolve symptoms, or alter mortality. Adverse effects were poorly or rarely reported in the trials. Extrapyramidal symptoms were not more frequent with antipsychotics compared to nonantipsychotic drug regimens, and no different for typical compared to atypical antipsychotics.

Anesthetic Immunomodulation of the Neuroinflammation in Postoperative Cognitive Dysfunction

Postoperative delirium and cognitive dysfunction are phenomena that are associated with increases in morbidity, mortality, and resource utilization after surgery. This review scrutinized a number of studies in order to better characterize the biochemical basis for associated cognitive dysfunction and delirium, with particular focus paid to the interactions of the cholinergic system with innate immunity and how the modulation of the immune system contributes to associated neuroinflammation. Despite the clinical impact of postoperative cognitive dysfunction, evidence-based protocols for the prevention and treatment of these disorders are still lacking. Several previous trials have attempted to prevent or treat clinical manifestation by modulation of the cholinergic system with acetylcholinesterase inhibitors, the results of which have been largely ambiguous at best. As the biochemical basis of postoperative cognitive dysfunction becomes more clearly defined, future research into therapeutics based on immune modulation and treatment of neuroinflammation may prove to be very promising.

Delirium

Delirium is a common, often underdiagnosed, geriatric syndrome characterized by an acute change in attention and consciousness. As a neuropsychiatric disorder with an underlying organic cause, delirium has been considered a diagnosis reserved for the hospital setting. However, delirium is known to occur as both an acute and subacute condition that carries significant morbidity and mortality. Combined with its association with dementia and aging, this makes delirium an important topic for primary care providers to become more familiar with as they are tasked with caring for an aging population.

Peri- and postoperative cognitive and consecutive functional problems of elderly patients

PURPOSE OF REVIEW

From an elderly patient's perspective, acute and chronic cognitive disturbances are among the most harmful complications that can occur following surgery. For elderly patients, these complications often mean the end of an independent life. This article focuses on this serious aspect, which is increasingly prevalent in our aging society. Cognitive disturbances are associated with severe outcome impairments and increased mortality. This article aims to provide a current overview regarding the diagnosis, pathophysiology, prevention, and treatment of this severe social problem.

RECENT FINDINGS

The current knowledge of risk factors, diagnosis, prevention, and treatment of postoperative delirium and postoperative cognitive dysfunction should help to raise awareness and improve the outcome of delirious patients, particularly in the elderly population.

SUMMARY

Especially in elderly patients, postoperative delirium constitutes a common, severe complication. Early diagnosis and supportive treatment are essential to improve outcome. To date, no pharmacological treatment strategy was effective, so that further research about the underlying pathophysiology and the development of treatment strategies are urgently required.

Molecular and Functional Neuroscience in Immunity

The nervous system regulates immunity and inflammation. The molecular detection of pathogen fragments, cytokines, and other immune molecules by sensory neurons generates immunoregulatory responses through efferent autonomic neuron signaling. The functional organization of this neural control is based on principles of reflex regulation. Reflexes involving the vagus nerve and other nerves have been therapeutically explored in models of inflammatory and autoimmune conditions, and recently in clinical settings. The brain integrates neuro-immune communication, and brain function is altered in diseases characterized by peripheral immune dysregulation and inflammation. Here we review the anatomical and molecular basis of the neural interface with immunity, focusing on peripheral neural control of immune functions and the role of the brain in the model of the immunological homunculus. Clinical advances stemming from this knowledge within the framework of bioelectronic medicine are also briefly outlined.

Antipsychotics, Delirium, and Acute Respiratory Distress Syndrome: What Is the Link?

Acute respiratory distress syndrome (ARDS) is an acute inflammatory process that impairs the ability of the lungs to oxygenate and ultimately leads to respiratory failure. Patients who develop ARDS often have prolonged and complicated hospital courses putting them at risk for intensive care unit (ICU) delirium. Patients with ICU delirium often need chemical sedation, mechanical ventilation, prolonged duration of ICU and hospital stays, and they experience long-term cognitive impairment and increased mortality. In a patient with ARDS, ICU delirium further complicates the hospital course and increases the risk of morbidity and mortality. Antipsychotics are prescribed to decrease the severity and duration of ICU delirium, thus potentially decreasing their risk of morbidity and mortality. However, antipsychotics are associated with many adverse effects including respiratory failure. Given the long-term sequelae associated with the development of ICU delirium and the risks associated with antipsychotic use, clinicians must weigh the risks and benefits of antipsychotic use. This review investigates the interrelationship between ARDS, delirium, and antipsychotic use. In addition to discussing relevant studies evaluating antipsychotics for the prevention and treatment of delirium, we investigate safety concerns with the use of antipsychotics, especially as they relate to ARDS. Using the data compiled in this review, clinicians can make an informed decision about the use of antipsychotics for the prevention or treatment of delirium, with special consideration for their patients with ARDS. Future studies are needed to critically evaluate antipsychotic timing, dose, and duration for the prevention and treatment of ICU delirium and specifically evaluate the impact in special populations, particularly patients with ARDS.

Delirium in the Elderly

Delirium is defined as an acute disturbance in attention and cognition, with significant associated morbidity and mortality. This article discusses the basic epidemiology of delirium and approaches to diagnosing, assessing, and working up patients for delirium. It delineates the pathophysiology and underlying predisposing and precipitating factors for delirium. It also discusses recent advances in prevention and treatment, particularly multicomponent, nonpharmacological interventions.

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.

An exploratory study of candidate gene(s) for Delirium Tremens: Adding the new cholinergic dimension to the conundrum

BACKGROUND AND AIMS

Delirium Tremens (DT) is the most severe form of alcohol withdrawal syndrome, with a potential risk of mortality. Search for the predictors of DT led to study of candidate genes, with inconsistent and inconclusive results. This study aimed to explore the association of various candidate gene polymorphisms and DT in a case-control design.

METHODS

This was a genetic association study with a case control design. Two hundred ten Alcohol dependent (AD) male subjects and 200 age matched controls were recruited. DT was diagnosed with the help of Semi-structured Assessment for Genetics of Alcoholism. SNP genotyping was done using TaqMan assay by real time PCR (q-PCR).

RESULTS

T allele carrying status (GT and TT) [rs1824024] of muscarinic cholinergic receptor 2 (CHRM2) was found to be significantly associated with DT. When compared to the general population, this genetic polymorphism was not found to be more common in alcohol dependence per se, which excludes the possibility of spurious association between CHRM2 and DT. Withdrawal seizure was more common in the DT group and came out to be one of the important predictors of DT. However, the genetic association was found to be specific for DT, not related to withdrawal seizures.

CONCLUSION

The present research added a new cholinergic dimension in the genetic association and biological mechanism of DT.

Diagnostic accuracy of delirium assessment methods in critical care patients

PURPOSE

Delirium is a disorder of decreased ability to focus, sustain or shift attention, change in cognition and or perception. The main objective was to evaluate the diagnostic accuracy of Confusion Assessment Method for the ICU (CAM-ICU) and Intensive Care Delirium Screening Checklist (ICDSC) among the nursing and medical staff in a multidisciplinary ICU.

METHODS AND MATERIAL

Three hundred ten verbally communicating and non-communicating patients (mean age in years 47.9, standard deviation [SD] 14.5, mean Acute Physiology and Chronic Health Evaluation II score 13.8, SD 6.4) were assessed by a psychiatrist, nurse and intensivist for delirium. Inter-rater agreement was measured by Cohen's kappa coefficient. Sensitivity, specificity, predictive values, likelihood ratios and diagnostic odds ratio (DOR) were calculated.

RESULTS

CAM-ICU showed higher sensitivity and DOR (84%, 86.1) compared to ICDSC (78%, 36.9). ICDSC had specificity and positive predictive value (94.5%, 92%) equal to that of CAM-ICU. For both the assessment methods (CAM-ICU and ICDSC), DORs for intensivists (120.5, 53.0) were relatively higher than nurses (67.0, 27.0).

CONCLUSIONS

In our mixed ICU population, CAM-ICU remained more sensitive than ICDSC. Though sensitivity and DOR were higher for medical staff, other diagnostic parameters were similar for both medical and nursing staff.

Rivastigmine patch reduces the incidence of postoperative delirium in older patients with cognitive impairment

OBJECTIVE

To date, data regarding the efficacy of acetylcholinesterase inhibitors in preventing postoperative delirium (POD) are inconsistent and conflicting. Older individuals with cognitive dysfunction are thought to show POD more frequently. Our aim was to study the effectiveness of rivastigmine prophylaxis on the incidence, severity, and risk factors for POD in older patients with cognitive impairment undergoing hip fracture surgery.

METHODS

Of 62 older patients with cognitive impairment about to undergo surgery after a hip fracture, 31 were randomly assigned to receive a rivastigmine patch from 3 days before to 7 days after the operation (Group I), and the other 31 did not receive a rivastigmine patch (Group II). The two groups were compared with regard to incidence and severity of delirium on postoperative days 2 or 3 and 7. Multivariate logistic regression analysis was performed to assess factors associated with POD.

RESULTS

Postoperative delirium occurred in five Group I patients and 14 Group II patients (p = 0.013). The mean severity of delirium in the two groups as determined by the Delirium Rating Scale was 2.2 and 6.2 respectively (p = 0.033). The odds ratio for POD was 0.259 (95% CI: 0.074-0.905, p = 0.034) after adjusting for American Society of Anesthesiologists score (p = 0.058), age (p = 0.203), and gender (p = 0.560). There were no rivastigmine-related perioperative complications.

CONCLUSION

Perioperative rivastigmine patch application could reduce the occurrence of POD in older patients with low cognitive status. Copyright © 2016 John Wiley & Sons, Ltd.