Delirium and depression: inter-relationship and clinical overlap in elderly people

Psychiatric Morbidity After Critical Illness

Critical illness survivors frequently have substantial psychiatric morbidity, including posttraumatic stress, depression, and anxiety symptoms. Prior psychiatric illness is a potent predictor of postcritical illness psychiatric morbidity. Early emotional distress and memories of frightening psychotic and nightmarish intensive care unit (ICU) experiences are risk factors for longer term psychiatric morbidity. ICU diaries may be effective in decreasing psychiatric morbidity after critical illness, though these and other interventions deserve further study.

Delirium clinical motor subtypes: a narrative review of the literature and insights from neurobiology

INTRODUCTION

Clinical motor subtypes have been long recognised in delirium and, despite a growing body of research, a lack of clarity exists regarding the importance of these motor subtypes. The aims of this review are to (1) examine how the concept of motor subtypes has evolved, (2) explore their relationship to the clinical context, (3) discuss the relationship between the phenomenology of delirium and motor activity, (4) discuss the application of neurobiology to the theory of delirium motor subtypes, and (5) identify methodological issues and provide solutions for further studies.

METHODS

The following databases were searched: PubMed, PsychInfo, EBSCO, Medline, BioMed central and Science Direct. Inclusion criteria specified peer-reviewed research assessing delirium motor subtypes published between 1990 and 2016.

RESULTS

Sixty-one studies met the inclusion criteria. The majority of studies (n = 50) were found to use validated psychometric tools, while the remainder (n = 11) used clinical criteria. The majority of studies (n = 45) were conducted in the medical setting, while the remainder were in the ICU/post-operative setting (n = 17).

CONCLUSION

Although host sensitivities (e.g. frailty) and exogenous factors (e.g. medication exposure) may determine the type of motor disturbance, it remains unclear to what extent motor subtypes are influenced by other features of delirium. The use of more specialised tools (e.g. delirium motor subtyping scale), may enable researchers to develop an approach to delirium that has a greater nosological consistency. Future studies investigating delirium motor subtypes may benefit from enhanced theoretical considerations of the dysfunctional neural substrate of the delirious state.

When psychiatric symptoms reflect medical conditions

The brain dysfunction associated with certain medical and neurological conditions can produce essentially any psychiatric symptom. This means there is always a chance that presentations thought to be 'psychiatric' are actually explained by unidentified medical pathology. This paper aims to outline an approach to minimise these missed diagnoses.

A Novel Stress-Diathesis Model to Predict Risk of Post-operative Delirium: Implications for Intra-operative Management

Introduction: Risk assessment for post-operative delirium (POD) is poorly developed. Improved metrics could greatly facilitate peri-operative care as costs associated with POD are staggering. In this preliminary study, we develop a novel stress-diathesis model based on comprehensive pre-operative psychiatric and neuropsychological testing, a blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) carbon dioxide (CO₂) stress test, and high fidelity measures of intra-operative parameters that may interact facilitating POD. Methods: The study was approved by the ethics board at the University of Manitoba and registered at clinicaltrials.gov as NCT02126215. Twelve patients were studied. Pre-operative psychiatric symptom measures and neuropsychological testing preceded MRI featuring a BOLD MRI CO₂ stress test whereby BOLD scans were conducted while exposing participants to a rigorously controlled CO₂ stimulus. During surgery the patient had hemodynamics and end-tidal gases downloaded at 0.5 hz. Post-operatively, the presence of POD and POD severity was comprehensively assessed using the Confusion Assessment Measure -Severity (CAM-S) scoring instrument on days 0 (surgery) through post-operative day 5, and patients were followed up at least 1 month post-operatively. Results: Six of 12 patients had no evidence of POD (non-POD). Three patients had POD and 3 had clinically significant confusional states (referred as subthreshold POD; ST-POD) (score ≥ 5/19 on the CAM-S). Average severity for delirium was 1.3 in the non-POD group, 3.2 in ST-POD, and 6.1 in POD (F-statistic = 15.4, p < 0.001). Depressive symptoms, and cognitive measures of semantic fluency and executive functioning/processing speed were significantly associated with POD. Second level analysis revealed an increased inverse BOLD responsiveness to CO₂ pre-operatively in ST-POD and marked increase in the POD groups when compared to the non-POD group. An association was also noted for the patient population to manifest leucoaraiosis as assessed with advanced neuroimaging techniques. Results provide preliminary support for the interacting of diatheses (vulnerabilities) and intra-operative stressors on the POD phenotype. Conclusions: The stress-diathesis model has the potential to aid in risk assessment for POD. Based on these initial findings, we make some recommendations for intra-operative management for patients at risk of POD.

Pre-stroke apathy symptoms are associated with an increased risk of delirium in stroke patients

Neuropsychiatric symptoms can be interrelated to delirium. We aimed to investigate an association between pre-stroke neuropsychiatric symptoms and the risk of delirium in stroke patients. We included 606 patients (median age: 73, 53% female) with stroke or transient ischemic attack admitted within 48 hours from symptoms onset. We assessed delirium on a daily basis during the first 7 days of hospitalization. To make diagnosis of delirium we used DSM-5 criteria. We used Neuropsychiatric Inventory to assess neuropsychiatric symptoms occurring within 4 weeks prior to stroke. We diagnosed delirium in 28.2% of patients. On univariate analysis, higher score of pre-stroke depression (OR: 1.58, 95% CI: 1.04-2.40, P = 0.03), apathy (OR: 2.23, 95% CI: 1.44-3.45, P < 0.01), delusions (OR: 2.00, 95% CI: 1.09-3.68, P = 0.03), hallucinations (OR: 2.39, 95% CI: 1.19-4.81, P = 0.01) and disinhibition (OR: 2.10, 95% CI: 1.04-4.25, P = 0.04) was associated with the increased risk of delirium. On multivariate analysis adjusted for age, atrial fibrillation, diabetes mellitus, stroke severity, right hemisphere lesion, pre-stroke cognitive decline, pre-stroke disability and infections, higher apathy score (OR: 2.03, 95% CI: 1.17-3.50, P = 0.01), but no other neuropsychiatric symptoms, remained independent predictor of delirium. We conclude that pre-stroke apathy symptoms are associated with increased risk of delirium in stroke patients.

Using Selective Serotonin Reuptake Inhibitors and Serotonin-Norepinephrine Reuptake Inhibitors in Critical Care: A Systematic Review of the Evidence for Benefit or Harm

OBJECTIVE

Selective serotonin reuptake inhibitor/serotonin-norepinephrine reuptake inhibitors are among the most commonly prescribed drugs in patients admitted to the ICU. Our objective was to systematically review available literature for evidence of benefit or harm in ICU patients resulting from chronic effects, continued use, or withdrawal.

DATA SOURCES

Medline, Embase, and Cochrane Central Register of Controlled Trials (1990 to November 2014).

STUDY SELECTION

We searched for studies of ICU patients with recorded selective serotonin reuptake inhibitor/serotonin-norepinephrine reuptake inhibitor prescription before or during admission, and reporting morbidity, mortality, adverse events, and resource measures like ICU length of stay. We considered all study designs. We excluded studies of deliberate overdose and depression in non-ICU settings. Two authors independently and in duplicate screened citations and reviewed text of studies to apply selection criteria.

DATA EXTRACTION

Two authors abstracted data on patient characteristics in exposed and control groups; use of selective serotonin reuptake inhibitor/serotonin-norepinephrine reuptake inhibitors previously or during ICU; comparator intervention; and outcomes, and also assessed methodologic quality.

DATA SYNTHESIS

The database search retrieved 4,172 unique citations, of which 289 were reviewed, and 13 studies representing a total of 20,048 patients met selection criteria. There were five cohort studies, one case series, and seven case reports. Only one case report suggested benefit from selective serotonin reuptake inhibitor/serotonin-norepinephrine reuptake inhibitor use and 11 studies reported morbidity in patients using these medications at admission to ICU. However, due to inadequate drug administration reporting, it was generally unclear if outpatient selective serotonin reuptake inhibitor/serotonin-norepinephrine reuptake inhibitors were continued in ICU, complicating interpretation.

CONCLUSIONS

There may be excess morbidity in critically ill selective serotonin reuptake inhibitor/serotonin-norepinephrine reuptake inhibitor users, but uncertainty remains whether this is due to chronic effects, ongoing use, or drug withdrawal. Further research with improved standards of drug administration reporting is needed to help clinicians decide when to use selective serotonin reuptake inhibitor/serotonin-norepinephrine reuptake inhibitors in critically ill patients.

Intraoperative ketamine for prevention of postoperative delirium or pain after major surgery in older adults: an international, multicentre, double-blind, randomised clinical trial

BACKGROUND

Delirium is a common and serious postoperative complication. Subanaesthetic ketamine is often administered intraoperatively for postoperative analgesia, and some evidence suggests that ketamine prevents delirium. The primary purpose of this trial was to assess the effectiveness of ketamine for prevention of postoperative delirium in older adults.

METHODS

The Prevention of Delirium and Complications Associated with Surgical Treatments [PODCAST] study is a multicentre, international randomised trial that enrolled adults older than 60 years undergoing major cardiac and non-cardiac surgery under general anaesthesia. Using a computer-generated randomisation sequence we randomly assigned patients to one of three groups in blocks of 15 to receive placebo (normal saline), low-dose ketamine (0·5 mg/kg), or high dose ketamine (1·0 mg/kg) after induction of anaesthesia, before surgical incision. Participants, clinicians, and investigators were blinded to group assignment. Delirium was assessed twice daily in the first 3 postoperative days using the Confusion Assessment Method. We did analyses by intention-to-treat and assessed adverse events. This trial is registered with clinicaltrials.gov, number NCT01690988.

FINDINGS

Between Feb 6, 2014, and June 26, 2016, 1360 patients were assessed, and 672 were randomly assigned, with 222 in the placebo group, 227 in the 0·5 mg/kg ketamine group, and 223 in the 1·0 mg/kg ketamine group. There was no difference in delirium incidence between patients in the combined ketamine groups and the placebo group (19·45% vs 19·82%, respectively; absolute difference 0·36%, 95% CI -6·07 to 7·38, p=0·92). There were more postoperative hallucinations (p=0·01) and nightmares (p=0·03) with increasing ketamine doses compared with placebo. Adverse events (cardiovascular, renal, infectious, gastrointestinal, and bleeding), whether viewed individually (p value for each >0·40) or collectively (36·9% in placebo, 39·6% in 0·5 mg/kg ketamine, and 40·8% in 1·0 mg/kg ketamine groups, p=0·69), did not differ significantly across groups.

INTERPRETATION

A single subanaesthetic dose of ketamine did not decrease delirium in older adults after major surgery, and might cause harm by inducing negative experiences.

FUNDING

National Institutes of Health and Cancer Center Support.

Activation of sigma-1 receptor chaperone in the treatment of neuropsychiatric diseases and its clinical implication

Endoplasmic reticulum (ER) protein sigma-1 receptor represents unique chaperone activity in the central nervous system, and it exerts a potent influence on a number of neurotransmitter systems. Several lines of evidence suggest that activation of sigma-1 receptor plays a role in the pathophysiology of neuropsychiatric diseases, as well as in the mechanisms of some therapeutic drugs and neurosteroids. Preclinical studies showed that some selective serotonin reuptake inhibitors (SSRIs; fluvoxamine, fluoxetine, excitalopram), donepezil, and ifenprodil act as sigma-1 receptor agonists. Furthermore, sigma-1 receptor agonists could improve the N-methyl-D-aspartate (NMDA) antagonist phencyclidine (PCP)-induced cognitive deficits in mice. A study using positron emission tomography have demonstrated that an oral administration of fluvoxamine or donepezil could bind to sigma-1 receptor in the healthy human brain, suggesting that sigma-1 receptor might be involved in the therapeutic mechanisms of these drugs. Moreover, case reports suggest that sigma-1 receptor agonists, including fluvoxamine, and ifenprodil, may be effective in the treatment of cognitive impairment in schizophrenia, delirium in elderly people, and flashbacks in post-traumatic stress disorder. In this review article, the author would like to discuss the clinical implication of sigma-1 receptor agonists, including endogenous neurosteroids, in the neuropsychiatric diseases.