Depressive symptoms and the risk of incident delirium in older hospitalized adults

Association between antidepressant use and delirium in older adults: an analysis of the World Health Organization's global pharmacovigilance database

BACKGROUND

Psychoactive drugs frequently cause delirium adverse events in older adults. However, few data on the relationship between antidepressants and delirium are available. Here, we investigated the association between antidepressant prescription and pharmacovigilance reports of delirium in older adults.

METHODS

Using the World Health Organization's VigiBase® global pharmacovigilance database from 1967 to 2022, we performed a disproportionality analysis in order to probe the putative associations between each antidepressant class (non-selective monoamine reuptake inhibitors (NSMRIs), selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), monoamine oxidase inhibitors (MAOIs), alpha-2-adrenergic receptor antagonists, and other antidepressants) and reports of delirium in people aged 65 or over. We calculated the reporting odds ratios (r-OR) and their 95% confidence interval ([95%CI]) with logistic regression models before and after adjustment for confounding factors. Secondary analyses were performed for each drug and within each class by age group (65-74, and 75 and over). We also studied the reports of concomitant delirium and hyponatremia.

RESULTS

Our main analysis included 87,524 cases of delirium. After adjustment for confounders, a significant association was found between delirium and all antidepressant classes other than SNRIs. Intraclass disparities were found for the association between the most frequently prescribed antidepressants and reports of delirium. An elevated risk of reports of concomitant delirium and hyponatremia was found for SSRIs (4.46 [4.01-4.96]), SNRIs (1.25 [1.07-1.46]), MAOIs (1.72 [1.41-2.09]), and the "other antidepressants" class (1.47 [1.30-1.65]).

CONCLUSIONS

There was a significant association between reports of delirium and antidepressant classes (other than SNRIs). However, this association varied from one drug to another within a given antidepressant class. Moreover, this association could not always be explained by antidepressant-induced hyponatremia.

Preoperative Virtual Reality to Expose Patients With Breast Cancer to the Operating Room Environment: Feasibility and Pilot Case Series Study

BACKGROUND

Clinically elevated preoperative distress and anxiety are common among patients undergoing cancer surgery. Preoperative interventions have been developed to mitigate this distress and anxiety but are inconsistent in efficacy and feasibility for broad implementation.

OBJECTIVE

This preliminary pilot study aims to assess the feasibility and utility of a newly developed virtual reality (VR) intervention to expose patients awaiting breast cancer surgery to the operating room environment and a simulation of anesthetic induction.

METHODS

Patients undergoing breast cancer surgery (N=7) were assigned to the VR intervention or control (treatment as usual) group and completed self-report measures of distress and anxiety before surgery, on the day of surgery, and after surgery (5 and 30 d postoperatively). Those in the intervention group trialed the VR simulation 1 to 2 weeks preoperatively and provided qualitative and quantitative feedback. We assessed the feasibility of recruitment capability and study design and evaluated participants' impressions of the intervention using self-report rating scales and open-ended questions. We also descriptively examined distress and anxiety levels throughout the duration of the study.

RESULTS

Recruitment occurred between December 2021 and December 2022 and progressed slowly (rate: 1 participant/7 wk on average; some hesitancy because of stress and being overwhelmed). All participants who consented to participate completed the entire study. All participants were female and aged 56 (SD 10.56) years on average. In total, 57% (4/7) of the participants were assigned to the intervention group. On average, intervention participants spent 12 minutes engaged in the VR simulation. In general, the intervention was rated favorably (eg, clear information, enjoyable, and attractive presentation; mean% agreement 95.00-96.25, SD 4.79-10.00) and as helpful (mean% agreement 87.50, SD 25.00). Participants described the intervention as realistic (eg, "It was realistic to my past surgical experiences"), impacting their degree of preparedness and expectations for surgery (eg, "The sounds and sights and procedures give you a test run; they prepare you for the actual day"), and having a calming or relaxing effect (eg, "You feel more relaxed for the surgery").

CONCLUSIONS

This preoperative VR intervention demonstrated preliminary feasibility among a sample of patients undergoing breast cancer surgery. Results and participant feedback will inform modifications to the VR intervention and the study design of a large-scale randomized controlled trial to examine the efficacy of this intervention.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04544618; https://clinicaltrials.gov/study/NCT04544618.

Associations between depression symptom burden and delirium risk: a prospective cohort study

BACKGROUND AND OBJECTIVES

Delirium and depression are increasingly common in aging. There is considerable clinical overlap, including shared symptoms and comorbid conditions, including Alzheimer's disease (AD), functional decline, and mortality. Despite this, the long-term relationship between depression and delirium remains unclear. This study assessed the associations of depression symptom burden and its trajectory with delirium risk in a 12-year prospective study of older individuals during hospitalization.

RESEARCH DESIGN AND METHODS

319,141 UK biobank participants between 2006-2010 (mean 58y [range 37-74, SD=8], 54% female) reported frequency (0-3) of four depressive symptoms (mood, disinterest, tenseness, or lethargy) in the preceding 2 weeks, and aggregated into a depressive symptom burden score (0-12). New-onset delirium was obtained from hospitalization records during 12y median follow-up. 40,451 (mean age 57±8; range 40-74y) had repeat assessment on average 8y after their first. Cox proportional hazard models examined whether depression symptom burden and trajectory predicted incident delirium during hospitalization.

RESULTS

5,753 (15 per 1000) newly developed delirium during follow-up. Increased risk for delirium was seen for mild (aggregated scores 1-2, hazards ratio, HR=1.16, [95% confidence interval 1.08-1.25], p<0.001), modest (scores 3-5, 1.30 [1.19-1.43], p<0.001) and severe (scores ≥ 5, 1.38 [1.24-1.55], p<0.001) depressive symptoms, versus none in the fully adjusted model. These findings were independent of the number of hospitalizations and consistent across hospitalization settings (e.g., surgical, medical, or critical care) and specialty (e.g., neuropsychiatric, cardiorespiratory or other). Worsening depression symptoms (≥1 point increase), compared to no change/improved score, were associated with an additional 39% increased risk (1.39 [1.03-1.88], p=0.03) independent of baseline depression burden. The association was strongest in those over 65y at baseline (p for interaction <0.001).

DISCUSSION AND IMPLICATIONS

Depression symptom burden and worsening trajectory predicted delirium risk during hospitalization. Increased awareness of subclinical depression symptoms may be warranted for delirium prevention.

Practical Application of a Battery of Brief Tools to Evaluate Geriatric Medical Inpatients for the Three Ds

OBJECTIVE

The investigators aimed to identify the clinical characteristics of patients with or without delirium and preexisting depression, dementia, both, or neither by using validated tools easily administered in clinical practice.

METHODS

In this cross-sectional prospective observational study conducted in Medellín, Colombia, 200 geriatric inpatients were evaluated with the Delirium Diagnostic Tool-Provisional (DDT-Pro), Informant Questionnaire on Cognitive Decline in the Elderly, Hachinski Ischemic Scale, Cornell Scale for Depression in Dementia, and Charlson Comorbidity Index-short form. Delirium motor subtype, mortality, and length of hospital stay were assessed.

RESULTS

The study included 134 patients without delirium (67%), 14 with delirium only (7%), 16 with delirium and dementia (8%), 13 with delirium and depression (7%), and 23 with delirium, dementia, and depression (the three Ds) (12%). Prevalence rates of dementia (59%) and depression (55%) among 66 patients with delirium were higher than prevalence rates among patients without delirium (13% and 28%, respectively), suggesting that both conditions are risk factors. Main medical diagnoses, mortality, and dementia type did not differ among groups. Motor subtypes were similar among delirium groups. Patients in the delirium groups, except those in the delirium and depression group, were older than patients without delirium. Medical burden was highest among the patients with delirium and dementia and those with all three conditions. Delirium and dementia were more severe when comorbid with each other. Depression was most severe among patients with delirium and depression. Patients with all three conditions had a longer length of hospital stay than those without delirium.

CONCLUSIONS

Using brief tools to detect dementia and depression in conjunction with the DDT-Pro to assess delirium diagnosis and severity is feasible and enables a more in-depth evaluation of elderly hospitalized patients. Because previous longitudinal research suggests that these comorbid conditions influence prognosis following a delirium episode, better identification of the three Ds offers proactive interventional opportunities. Depression is an underrecognized risk factor for delirium.

Depression and anxiety increase the odds of developing delirium in ICU patients; a prospective observational study

BACKGROUND

Delirium is prevalent among hospitalised patients, especially in critically ill patients. Preventing delirium by recognising its modifiable risk factors could improve life quality, decrease mortality and restrain its devastating consequences.

METHOD

We investigated 50 patients who had been hospitalised in the general ICU and monitored them for developing delirium. We employed CAM and CAM-ICU Scales to assess delirium, RASS score to determine the consciousness level, HADS questionnaire for anxiety and depression, and the demographic data questionnaire.

RESULTS

We found that 20% of ICU patients developed delirium and found a meaningful correlation between the incident delirium, older ages, visual impairment, and higher anxiety and depression scores (HADS) of first and second days of hospitalisation. By utilising logistic regression, we found that older ages, visual impairment, higher anxiety and depression scores (HADS) of the first day of hospitalisation were statistically significant to predict the risk model of developing delirium.

CONCLUSION

Depressive and anxiety symptoms were associated with higher odds of transitioning to delirium; so, at the admission time, it may be useful to screen patients for the symptoms of affective disorders, particularly, who are at higher risks for developing delirium.

Delirium Post-Stroke: Short- and Long-Term Effect on Depression, Anxiety, Apathy and Aggression (Research Study-Part of PROPOLIS Study)

Background: Stroke patients are particularly vulnerable to delirium episodes, but very little is known about its subsequent adverse mental health outcomes. The author’s objective was to explore the association between in-hospital delirium and depression, anxiety, anger and apathy after stroke. Methods: A total of 750 consecutive patients with acute stroke or transient ischemic attack, were screened for delirium during hospitalization. Patients underwent mental health evaluation in hospital, 3 and 12 months post-stroke; depression, apathy, anxiety and anger were the outcomes measured at all evaluation check points. Results: Delirium was an independent risk factor for depression (OR = 2.28, 95%CI 1.15–4.51, p = 0.017) and aggression (OR = 3.39, 95%CI 1.48–7.73, p = 0.004) at the hospital, for anxiety 3 months post-stroke (OR = 2.83, 95%CI 1.25–6.39, p = 0.012), and for apathy at the hospital (OR = 4.82, 95%CI 2.25–10.47, p < 0.001), after 3 (OR = 3.84, 95%CI 1.31–11.21, p = 0.014) and 12 months (OR = 4.95, 95%CI 1.68–14.54, p = 0.004) post stroke. Conclusions: The results of this study confirm, that mental health problems are very frequent complications of stroke. Delirium in the acute phase of stroke influences mental health of patients. This effect is especially significant in the first months post-stroke and vanishes with time, which suggests that in-hospital delirium might not be a damaging occurrence in most measures of mental health problems from a long-term perspective.

Postoperative delirium in the elderly: the potential neuropathogenesis

Postoperative delirium (POD) is a neurobehavioral syndrome caused by dysfunction of neural activity mainly in elderly people. POD is not uncommon, but under-recognized, and often serious. Multifactorial causes including aging, acetylcholine deficiency, sleep deprivation and intraoperative hypoxia have been proposed attempting to explain the processes leading to the development of POD. To date, however, no specific pathophysiologic mechanism has been identified. Here, we summarize the five most prominent theories (neuronal aging, neuroinflammation, neurotransmitter imbalance, neuroendocrine activation, and network connectivity change) to explain the development of delirium. Understanding of the neuropathogenesis of delirium will help focus future research, and assist in developing prophylactic and treatment strategies.

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.

Cognitive Reserve and Postoperative Delirium in Older Adults

OBJECTIVES

To examine the role of cognitive reserve in reducing delirium incidence and severity in older adults undergoing surgery.

DESIGN

Prospective cohort study.

SETTING

Hospital.

PARTICIPANTS

Older adults (mean age 71.2, 65% women) undergoing elective orthopedic surgery (N = 142).

MEASUREMENTS

Incidence (Confusion Assessment Method) and severity (Memorial Delirium Assessment Scale) of postoperative delirium were the primary outcomes. Predictors included early- (literacy) and late-life (cognitive activities) proxies for cognitive reserve.

RESULTS

Forty-five participants (32%) developed delirium. Greater participation in cognitive activity was associated with lower incidence (odds ratio = 0.92 corresponding to increase of 1 activity per week, 95% confidence interval (CI) = 0.86-0.98, P = .006) and severity (B = -0.06, 95% CI = -0.11 to -0.01, P = .02) of delirium after adjustment for age, sex, medical illnesses, and baseline cognition. Greater literacy was not associated with lower delirium incidence or severity. Of individual leisure activities, reading books, using electronic mail, singing, and computer games were associated with lower dementia incidence and severity.

CONCLUSION

Greater late-life cognitive reserve was associated with lower delirium incidence and severity in older adults undergoing surgery. Interventions to enhance cognitive reserve by initiating or increasing participation in cognitive activities may be explored as a delirium prophylaxis strategy.

Depressive Symptoms Before, During, and After Delirium: A Literature Review

BACKGROUND

Delirium and depression are often thought of as mutually exclusive conditions. However, several studies cite depression as a risk factor for delirium whereas others note that patients with delirium often manifest depressive symptoms. Whether these depressive symptoms persist after delirium resolves remains unclear.

OBJECTIVES

This article reviews published studies that have investigated the relationship between depression and delirium.

METHODS

Literature searches on PubMed, CINAHL, Cochrane Library, and PsycInfo were conducted using search criteria "delirium" AND "depress⁎" as keywords or MeSH terms.

RESULTS

Of 722 search results, 10 prospective cohort studies were identified for inclusion. These studies were categorized regarding the time of assessment for depressive symptoms. Included studies varied greatly (regarding their index population, their methods of assessment, and their timing of assessments). Of the studies, 3 involved patients undergoing hip fracture repair. They demonstrated more severe depressive symptoms both during delirium and after delirium ended. Conversely, the other studies did not find any statistically significant correlations between the 2 conditions.

CONCLUSIONS

The literature suggests a correlation between depression and delirium in patients with hip fracture. Whether other specific populations have higher comorbidity is unclear. Unfortunately, studies varied widely in their methods, precluding a meta-analysis. Nonetheless, our review provides a foundation for future research.

Comprehensive Geriatric Assessment is a useful predictive tool for postoperative delirium after gastrointestinal surgery in old-old adults

AIM

To determine whether carrying out the Comprehensive Geriatric Assessment before operations would be useful for predicting complications, particularly postoperative delirium (POD), in old-old patients.

METHODS

A total of 517 patients aged 75 years and older, who underwent radical surgery for gastrointestinal cancer at Osaka University Hospital, were recruited for this observational study. The Comprehensive Geriatric Assessment components and assessment of performance status were carried out before surgery, and a record of postoperative complications including POD was made prospectively until discharge from hospital. The following morphological and clinical measurements were also obtained from the medical records: age, sex, disease type, previous history, comorbid lifestyle-related diseases, POD, postoperative complications, operative method, duration of operation, hemorrhage volume, blood transfusion volume, method of anesthesia, body mass index and blood tests.

RESULTS

POD appeared in 24.0% of the 517 patients who underwent surgery. Barthel Index, Mini-Mental State Examination, instrumental activities of daily living and Geriatric Depression Scale results were associated with the incidence of POD, and the Barthel Index, Mini-Mental State Examination and Instrumental Activities of Daily Living results were extracted as independent factors associated with the development of POD after adjusting for traditional risk factors for postoperative complications and performance status.

CONCLUSIONS

The Comprehensive Geriatric Assessment before gastrointestinal surgery can be a useful tool for predicting the development of POD in old-old patients. Geriatr Gerontol Int 2016; 16: 1036-1042.

Biomarkers of postoperative delirium and cognitive dysfunction

Elderly surgical patients frequently experience postoperative delirium (POD) and the subsequent development of postoperative cognitive dysfunction (POCD). Clinical features include deterioration in cognition, disturbance in attention and reduced awareness of the environment and result in higher morbidity, mortality and greater utilization of social financial assistance. The aging Western societies can expect an increase in the incidence of POD and POCD. The underlying pathophysiological mechanisms have been studied on the molecular level albeit with unsatisfying small research efforts given their societal burden. Here, we review the known physiological and immunological changes and genetic risk factors, identify candidates for further studies and integrate the information into a draft network for exploration on a systems level. The pathogenesis of these postoperative cognitive impairments is multifactorial; application of integrated systems biology has the potential to reconstruct the underlying network of molecular mechanisms and help in the identification of prognostic and diagnostic biomarkers.

Effect of the overlap syndrome of depressive symptoms and delirium on outcomes in elderly adults with hip fracture: a prospective cohort study

OBJECTIVES

To analyze the incidence of the overlap syndrome of depressive symptoms and delirium, risk factors, and independent and dose-response effect of the overlap syndrome on outcomes in elderly adults with hip fracture.

DESIGN

Prospective cohort study.

SETTING

University hospital.

PARTICIPANTS

Individuals with hip fracture without delirium (N = 277; aged 78.0 ± 8.2) consequently enrolled in a prospective cohort study.

MEASUREMENTS

Depressive symptoms were assessed using the Geriatric Depression Scale and cognitive status using the Short Portable Mental Status Questionnaire upon hospital admission. Incident delirium was assessed daily during the hospital stay using the Confusion Assessment Method. Information on complications acquired in the hospital, severity of complications, re-interventions, length of hospital stay, and 1-month mortality was recorded.

RESULTS

Thirty (10.8%) participants had depressive symptoms alone, 88 (31.8%) delirium alone, 60 (21.7%) overlap syndrome, and 99 (35.7%) neither condition. According to multivariate regression analysis, participants with the overlap syndrome had significantly higher incidence of vision impairment (P = .02), longer time-to-surgery (P = .03), and lower cognitive function (P < .001) than participants with no depressive symptoms and no delirium. In the adjusted regression analysis, participants with neither condition were at lower risk of complications than those with the overlap syndrome (P = .03). After adjustment, participants with the overlap syndrome were at higher risk of longer hospital stay independently (P = .003) and in a dose-response manner in the following order: no depression and no delirium, depressive symptoms alone, delirium alone, and the overlap syndrome (P = .002).

CONCLUSION

Depressive symptoms and delirium increase the likelihood of adverse outcomes after hip fracture in a step-wise manner when they coexist. To reduce the risk of adverse outcome in individuals with hip fracture, efforts to identify, prevent, and treat this condition need to be increased.

Estimating the effect of incident delirium on short-term outcomes in aged hip fracture patients through propensity score analysis

AIM

We aimed to evaluate the factors contributing to delirium after hip fracture and assess the effect of incident delirium on short-term clinical outcomes.

METHODS

A total of 270 non-delirious, consecutive hip fracture patients 60 years and older were included in a prospective cohort study. The patients were assessed with respect to physical status according to the American Society of Anesthesiologists classification, medical comorbidities with the Charlson Comorbidity Index, cognitive function with the Portable Mental Status Questionnaire and depression with the Geriatric Depressive Scale. Incident delirium was evaluated daily. Clinical outcomes and 1-month mortality were recorded.

RESULTS

Incident delirium was present in 53.0% of patients. Patients with delirium were older (P = 0.046), had higher American Society of Anesthesiologists and Charlson Comorbidity Index scores (P < 0.001), lower Portable Mental Status Questionnaire scores and higher Geriatric Depressive Scale scores (P < 0.001, P = 0.003, respectively). After adjusting for age, multivariate regression analysis in the first model showed that patients with delirium were at higher risk of reintervention plus death (P < 0.05), complications P < 0.001), a higher severity complication score (P < 0.05) and longer length of hospital stay (P < 0.001). In the second model, after adjusting for propensity score, patients with delirium were at higher risk of reintervention plus death (P < 0.05) and longer length of hospital stay (P < 0.01).

CONCLUSIONS

Patients who are older, with worse physical status, worse cognitive function and depression are more likely to develop delirium after hip fracture. Incident delirium has negative independent effects on short-term outcomes in elderly patients after hip fracture.

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

Delirium and depression are complex neuropsychiatric syndromes common in the elderly and are associated with poor health-care outcomes. Accurate diagnosis is essential to the provision of optimum health care for individuals with these conditions but is complicated by substantial clinical overlap in symptoms and comorbidities. A careful assessment of the patient's symptoms, including their context and time course, is needed for accurate diagnosis. Previous depression is common in patients with delirium and depressive illness is a recognised sequelae of delirium. The two syndromes seem to be caused by similar pathophysiological mechanisms, involving disturbances in stress and inflammatory responses, monoaminergic and melatonergic signalling, which point to new avenues for therapeutic intervention. Improved methods to assess delirium and depression in populations at high risk by virtue of their age, diminished cognitive reserve and physical frailty is a key target to achieve improved health-care outcomes in elderly individuals.

Cigarette smoking as a risk factor for delirium in hospitalized and intensive care unit patients. A systematic review

BACKGROUND

Active smokers are prevalent in hospitalized and critically ill patients. Cigarette smoking and nicotine withdrawal may increase delirium in these populations. This systematic review aims to determine whether active cigarette smoking increases the risk for delirium in hospitalized and intensive care unit (ICU) patients.

METHODS

A systematic search of English-, Spanish-, and French-language articles published from 1966 to April 2013 was performed. Studies were included if they measured cigarette smoking as a risk factor and delirium as an outcome in adult hospitalized or ICU patients. Methodologic quality of studies was assessed using both the validated Newcastle Ottawa Scale and an additional evidence-based quality rating scale.

RESULTS

A total of 14 cohort studies of surgical and ICU populations were included in the review. No studies in non-ICU inpatients were identified. The incidence of delirium ranged from 9 to 52%, and the prevalence of active smokers ranged from 9 to 44%. The quality of assessment for active smoking varied widely. None of the studies used biochemical measures to determine cigarette smoke exposure. Of the six studies restricting the smoking group to active smokers only, active smoking was independently associated with delirium in one study, trended toward an association in one study, and showed a dose response in one study. Quantitative summary measures were not calculated due to study heterogeneity and missing data.

CONCLUSIONS

There is currently insufficient evidence to determine if cigarette smoking is a risk factor for delirium. Future studies should consider using biochemical measures of cigarette smoke exposure to objectively quantify smoking behavior.

Nurse screening for delirium in older patients attending the emergency department

BACKGROUND

Delirium in older emergency department (ED) patients is common, associated with many adverse outcomes, and costly to manage. Delirium detection in the ED is almost universally poor.

OBJECTIVES

The authors aimed to develop a simple clinical risk screening tool that could be used by ED nurses as part of their initial assessment to identify patients at risk of delirium.

METHODS

A prospective cross-sectional study of patients 65 years and older attending a single ED.

RESULTS

Of 320 enrolled patients, 23 (7.2%) had delirium. Logistic regression analysis revealed 3 risk factors strongly associated with delirium risk: cognitive impairment, depression, and an abnormal heart rate/rhythm. Weighting these variables based on the strength of their association with delirium yielded a risk score from 0-4 inclusive. A cutoff of 2 or more in that score would have given a sensitivity of 87%, specificity of 70%, and NPV of 99%, while avoiding further diagnostic workup for delirium in approximately two-thirds of all patients, when used as an initial screen.

CONCLUSIONS

A simple risk screening tool using factors evident on initial nurse assessment can be used to identify patients at risk of delirium. Further trials are needed to test whether the tool improves patient outcomes.

A longitudinal study on delirium in nursing homes

OBJECTIVE

To investigate the evolution of delirium of nursing home (NH) residents and their possible predictors.

DESIGN

Post-hoc analysis of a prospective cohort assessment.

SETTING

Ninety NHs in Switzerland.

PARTICIPANTS

Included 14,771 NH residents.

MEASUREMENTS

The Resident Assessment Instrument Minimum Data Set and the Nursing Home Confusion Assessment Method were used to determine follow-up of subsyndromal or full delirium in NH residents using discrete Markov chain modeling to describe long-term trajectories and multiple logistic regression analyses to determine predictors of the trajectories.

RESULTS

We identified four major types of delirium time courses in NH. Increasing severity of cognitive impairment and of depressive symptoms at the initial assessment predicted the different delirium time courses.

CONCLUSION

More pronounced cognitive impairment and depressive symptoms at the initial assessment are associated with different subsequent evolutions of delirium. The presence and evolution of delirium in the first year after NH admission predicted the subsequent course of delirium until death.

Thirty-day prevalence of delirium among very old people: a population-based study of very old people living at home and in institutions

Delirium has mainly been studied in various patient samples and in people living in institutions. The present study investigates the 30-day prevalence of delirium in a population-based sample of very old people in northern Sweden and Finland. Seven hundred and eight persons aged 85 years and older from the GErontological Regional DAtabase (GERDA) were assessed. Information was also collected from relatives, carers and medical records. Assessments performed were among others the Organic Brain Syndrome (OBS) scale, the Mini Mental State Examination (MMSE), and the Geriatric Depression Scale-15 (GDS-15). Delirium, depression and dementia diagnoses were based on the Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) criteria. The prevalence of delirium was 17% among 85 year-olds, 21% among 90 year-olds and 39% among participants aged 95 years and older (p<0.001). Delirium prevalence among individuals without dementia was lower than among those with dementia (5% vs. 52%, p<0.001). Factors independently associated with delirium superimposed on dementia in a multivariate logistic regression model were depression (Odds Ratio (OR)=2.0, 95% Confidence Interval (CI)=1.2-3.3), heart failure (OR=2.1, 95% CI=1.2-3.7), institutional living (OR 4.4, 95% CI=2.4-8.2) and prescribed antipsychotics (OR=3.0, 95% CI=1.5-6.0). Delirium is highly prevalent among very old people with dementia. Depression, heart failure, institutional living and prescribed antipsychotic medication seem to be associated with delirium.

An update on delirium in the postoperative setting: prevention, diagnosis and management

Delirium is a serious and pervasive problem in the postoperative setting. Research to date has identified a number of key risk factors implicated in the development of delirium after surgical intervention, including advanced age, pre-existing cognitive impairment, lower pre-morbid functional status and history of psychiatric illness. Efforts to prevent postoperative delirium in the form of multi-component programs and prophylactic administration of medications have yielded some positive results. Studies investigating the effectiveness of various antipsychotics in the treatment of postoperative delirium have demonstrated somewhat mixed outcomes. Recent research has identified more sophisticated management of pain and sedation protocols as a way to prevent or mitigate delirium, with promising results. This chapter reviews the most recent literature pertaining to the prevention, diagnosis and management of postoperative delirium.

Presepsis depressive symptoms are associated with incident cognitive impairment in survivors of severe sepsis: a prospective cohort study of older Americans

OBJECTIVES

To test the hypothesis that presepsis depressive symptoms are associated with risk of new cognitive impairment in survivors of severe sepsis.

DESIGN

Prospective longitudinal cohort study.

SETTING

Population-based cohort of older U.S. adults interviewed as part of the Health and Retirement Study (1998-2006).

PARTICIPANTS

Four hundred forty-seven individuals with normal presepsis cognition who survived 540 hospitalizations for severe sepsis and completed at least one follow-up interview.

MEASUREMENTS

Severe sepsis was identified using a validated algorithm in Medicare claims. Depressive symptoms were assessed prospectively using a modified version of the Center for Epidemiologic Studies Depression Scale. Cognitive function was assessed using versions of the Telephone Interview for Cognitive Status (TICS). Logistic regression with robust standard errors was used to examine associations between substantial depressive symptoms at any interview before sepsis and incident cognitive impairment (mild or moderate to severe cognitive impairment) at any interview after sepsis.

RESULTS

The prevalence of substantial depressive symptoms in participants with normal cognition before sepsis was 38% (95% confidence interval (CI) = 34-42%). After severe sepsis, 18% (95% CI = 15-20%) of survivors had incident cognitive impairment. In unadjusted analyses, presepsis substantial depressive symptoms were associated with postsepsis incident cognitive impairment (odds ratio (OR) = 2.56, 95% CI = 1.53-4.27). After adjustment for demographics, health-risk behaviors, clinical characteristics of the sepsis episode, and presepsis TICS scores, substantial presepsis depressive symptoms remained the strongest factor associated with postsepsis incident cognitive impairment (OR = 2.58, 95% CI = 1.45-4.59).

CONCLUSION

Substantial presepsis depressive symptoms are independently associated with incident postsepsis cognitive impairment. Depressed older adults may be particularly at risk of developing cognitive impairment after a serious medical illness.

Depression, anxiety, and cardiac morbidity outcomes after coronary artery bypass surgery: a contemporary and practical review

Research to date indicates that the number of coronary artery bypass graft (CABG) surgery patients affected by depression (i.e., major, minor, dysthymia) approximates between 30% and 40% of all cases. A longstanding empirical interest on psychosocial factors in CABG surgery patients highlights an association with increased risk of morbidity in the short and longer term. Recent evidence suggests that both depression and anxiety increase the risk for mortality and morbidity after CABG surgery independent of medical factors, although the behavioral and biological mechanisms are poorly understood. Though neither depression nor anxiety seem to markedly affect neuropsychological dysfunction, depression confers a risk for incident delirium. Following a comprehensive overview of recent literature, practical advice is described for clinicians taking into consideration possible screening aids to improve recognition of anxiety and depression among CABG surgery patients. An overview of contemporary interventions and randomized, controlled trials are described, along with suggestions for future CABG surgery research.

The relationship between delirium duration, white matter integrity, and cognitive impairment in intensive care unit survivors as determined by diffusion tensor imaging: the VISIONS prospective cohort magnetic resonance imaging study*

OBJECTIVE

Evidence is emerging that delirium duration is a predictor of long-term cognitive impairment in intensive care unit survivors. Relationships between 1) delirium duration and brain white matter integrity, and 2) white matter integrity and long-term cognitive impairment are poorly understood and could be explored using magnetic resonance imaging.

DESIGN, SETTING, PATIENTS

A two-center, prospective cohort study incorporating delirium monitoring, neuroimaging, and cognitive testing in intensive care unit survivors.

MEASUREMENTS

Delirium was evaluated with the Confusion Assessment Method for the Intensive Care Unit and cognitive outcomes were tested at 3 and 12-month follow-up. Following the intensive care unit stay, fractional anisotropy, a measure of white matter integrity, was calculated quantitatively using diffusion tensor imaging with a 3-T magnetic resonance imaging scanner at hospital discharge and 3-month follow-up. We examined associations between 1) delirium duration and fractional anisotropy and 2) fractional anisotropy and cognitive outcomes using linear regression adjusted for age and sepsis.

RESULTS

A total of 47 patients with a median age of 50 yrs completed the diffusion tensor imaging-magnetic resonance imaging protocol. Greater duration of delirium (3 vs. 0 days) was associated with lower fractional anisotropy (i.e., reduced fractional anisotropy = white matter disruption) in the genu (-0.02; p = .04) and splenium (-0.01; p = .02) of the corpus callosum and anterior limb of the internal capsule (-0.02; p =.01) at hospital discharge. These associations persisted at 3 months for the genu (-0.02; p =.02) and splenium (-0.01; p = .004). Lower fractional anisotropy in the anterior limb of internal capsule at discharge and in genu of corpus callosum at three months was associated with worse cognitive scores at 3 and 12 months.

CONCLUSIONS

In this pilot investigation, delirium duration in the intensive care unit was associated with white matter disruption at both discharge and 3 months. Similarly, white matter disruption was associated with worse cognitive scores up to 12 months later. This hypothesis-generating investigation may help design future studies to explore these complex relationships in greater depth.

Delirium masquerading as depression

Objective:

Despite the high prevalence of delirium in palliative care settings, this diagnosis is frequently missed, particularly in patients with hypoactive delirium. These patients are also commonly misdiagnosed with depression because of the overlap in symptoms between the two diagnoses. Failure to promptly diagnose delirium can have significant ramifications in terms of delirium reversal, subsequent patient involvement in end-of-life decision making, and the recognition and treatment of other symptoms.

Method:

We report a case of a 63-year-old French-speaking woman admitted to our inpatient palliative care unit with colorectal cancer and a history of depression. This case report highlights the major challenges associated with making the diagnosis of delirium in a patient with a complex medical history, including depression.

Results:

The patient presented with symptoms of depressed mood and fluctuation in psychomotor activity, but failed to respond to an increase in her fluoxetine treatment in addition to methylphenidate and treatment of her hypothyroidism. A psychiatric assessment in her own language detected features of inattention and confirmed a diagnosis of delirium that was multifactorial, secondary to a combination of posterior reversible encephalopathy syndrome (PRES), hypothyroidism, hepatic dysfunction, and medication.

Significance of Results:

Subsyndromal delirium may present with mood lability, and as delirium and depression can coexist, clinicians should perform a delirium screen for all patients presenting with symptoms of depression, preferably in the patient's first language. Cognitive testing can be particularly helpful in distinguishing delirium, especially hypoactive delirium, from depression.

The usefulness of bright light therapy for patients after oesophagectomy

OBJECTIVES

The prevention of delirium is an important issue in the field of perioperative nursing. The objective of this study was to verify the usefulness of acute-stage bright light exposure on patients following oesophagectomy.

METHODS

The participants were oesophagectomy patients that were removed from their ventilators the day after surgery. After extubation, we assigned the participants to either the exposure group or control group. At Day 2 after surgery, the exposure group underwent two hours of bright light exposure for four days. In both groups, we monitored physical activity and autonomic activity. In addition, we scored the participants on the NEECHAM Scale and evaluated their postoperative delirium and postoperative arrhythmia.

RESULTS

On the nights of Days 4 and 5, the amount of activity of the exposure group was significantly lower and The sympathetic nervous index was significantly lower on the night of Day 5. The level of arrhythmia was lower in the exposure group and we observed a significant difference on the night of Day 4 and the daytime of Day 5 after surgery. The occurrence rate of postoperative delirium tended to be lower in the exposure group, but there was no significant difference. None of the participants in the exposure group had NEECHAM Scale scores below the cut-off value from the night of Day 4 onwards.

CONCLUSION

We conclude that postoperative bright light exposure adjusted the sleep-wakefulness cycle and improved the bed rest of patients. It was also indicated that bright light therapy is useful for reducing postoperative delirium.

Home food environment of older adults transitioning from hospital to home

Only anecdotal information is known about foods available in the home of hospital-discharged older adults. This study describes the home food environment of this population and examines associations between health/nutrition risk factors and ability to shop and prepare meals. Data were collected from 512 hospital-discharged older adults residing in 6 U.S. states; food available within the home was assessed. Most households had a variety of food present; however, 20% of households lacked fresh fruit, 15% lacked fresh vegetables, and 35% had no fresh meat. About 35% of participants reported an inability to both prepare meals and shop for food. Among those unable to do both activities, the prevalence of depressive symptoms, food-related anxiety, and poor self-rated health was significantly (p < 0.01) higher than those able to do both activities. Homebound older adults may face additional challenges to recuperation from illness based on inability to prepare meals, regardless of availability of food following hospital discharge.

Development of a frailty index for patients with coronary artery disease

OBJECTIVES

To construct a brief frailty index for older patients with coronary artery disease (CAD) undergoing coronary angiography that includes physical, cognitive, and psychosocial criteria and accurately predicts future disability and decline in health-related quality of life (HRQL).

DESIGN

Prospective cohort.

SETTING

An urban tertiary care hospital in Alberta, Canada.

PARTICIPANTS

Three hundred seventy-four patients aged 60 and older (73% male) undergoing cardiac catheterization for CAD between October 2003 and May 2007.

MEASUREMENTS

Potential frailty criteria examined at baseline (before the procedure) included measures of balance, gait speed, cognition, self-reported health, body mass index (BMI), depressive symptoms, and living alone. The outcomes assessed over 1 year were dependency in activities of daily living (ADLs) and HRQL.

RESULTS

The five best-fitting criteria from regression analyses for ADL decline were poor balance (risk ratio (RR)=2.4, 95% confidence interval (CI)=1.4–4.0), abnormal BMI (RR=1.8, 95% CI=1.1–3.0), impaired Trail-Making Test Part B performance (RR=2.3, 95% CI=1.3–4.2), depressive symptoms (RR=1.8, 95% CI=1.1–3.1), and living alone (RR=2.2, 95% CI=1.3–3.8). Using the five criteria as separate variables or as a summary frailty index yielded identical areas under the receiver operating characteristic curve (0.76, 95% CI=0.66–0.84). Patients with three or more criteria (vs none) were at statistically significant greater risk for increased disability (RR=10.4, 95% CI=4.4–24.2) and decreased HRQL (RR=4.2, 95% CI=2.3–7.4) after 1 year.

CONCLUSION

This brief frailty index including physical, cognitive, and psychosocial criteria was predictive of increased disability and decreased HRQL at 1 year in older patients with CAD undergoing angiography. This index may have applications for clinicians and researchers but requires further validation.

Aging, brain disease, and reserve: implications for delirium

Cognitive and brain reserve are well studied in the context of age-associated cognitive impairment and dementia. However, there is a paucity of research that examines the role of cognitive or brain reserve in delirium. Indicators (or proxy measures) of cognitive or brain reserve (such as brain size, education, and activities) pose challenges in the context of the long prodromal phase of Alzheimer disease but are diminished in the context of delirium, which is of acute onset. This article provides a review of original articles on cognitive and brain reserve across many conditions affecting the central nervous system, with a focus on delirium. The authors review current definitions of reserve. The authors identify indicators for reserve used in earlier studies and discuss these indicators in the context of delirium. The authors highlight future research directions to move the field ahead. Reserve may be a potentially modifiable characteristic. Studying the role of reserve in delirium can advance prevention strategies for delirium and may advance knowledge of reserve and its role in aging and neuropsychiatric disease generally.

Geriatric ward hospitalization reduced incidence delirium among older medical inpatients

OBJECTIVES

Most strategies for delirium prevention in older hospitalized patients are common good clinical geriatric care. We investigated whether acute geriatric ward (AGW) hospitalization, compared with acute general medical ward (AGMW) hospitalization,is associated with reduced incident delirium in older medical inpatients.

DESIGN

prospective observational study.

SETTING

a tertiary care, university hospital in Torino.

PARTICIPANTS

consecutive medical patients 70 years or older admitted from the emergency department to an AGW and to an AGMW were included.

MEASUREMENTS

Baseline measures included demography, functional and psychocognitive status, comorbidity, physiological and clinical severity of acute illness. Incident delirium was evaluated by qualified psychiatrists according to the Confusion Assessment Method and the Delirium Rating Scale.

RESULTS

Delirium occurred in 8 of 121 patients admitted to AGW (6.6%) and in 20 of 131 patients admitted to AGMW (15.2%). After adjustment for significant differences in baseline covariates between groups, AGW hospitalization remained independently associated with less incident delirium (relative risk 0.90, 95% confidence interval: 0.024-0.331, p <0.001). In a multivariable logistic model with delirium incidence as independent variable, AGW hospitalization was independently associated with lower delirium incidence (relative risk 0.039, 95% confidence interval: 0.007-0.214, p <0.001), whereas greater cognitive impairment (p <0.001), higher Acute Physiology and Chronic Health Evaluation II score (p 0.001) and recent stressful events (p <0.001) were associated with increased delirium incidence.

CONCLUSION

AGW hospitalization is associated with less incident delirium among older medical inpatients. Despite inherent limitations of observational studies, these hypothesis-generating findings add to previous evidence of potential benefit in delirium prevention from geriatric consultation in several hospital settings.

Predisposing factors associated with delirium among demented long-term care residents

This was a cross-sectional study to investigate predisposing factors associated with delirium among demented long-term-care residents and to assess the cumulative effect of these factors on the likelihood of having delirium. Of the 155 participants, 109 (70.3%) were found delirious according to the confusion assessment method. Among these individuals, age (OR = 1.07; 95% CI = 1.05-1.10) and severity of dementia (OR = 1.05; 95% CI = 1.03-1.07) were the most associated factors of delirium. The likelihood of being in delirium increased with the number of associated predisposing factors present (OR = 1.67; 95% CI = 1.11-2.51). Associated factors identified were level of functional autonomy, pain, depression, behavioral disturbances, number of medications, dehydration, fever, and malnutrition. Identification of predisposing factors will help nurses in detecting those residents in long-term care settings who are at high-risk for delirium, as well as in designing preventive intervention strategies for delirium, based on these factors.

The overlap syndrome of depression and delirium in older hospitalized patients

OBJECTIVES

To measure the prevalence, predictors, and posthospitalization outcomes associated with the overlap syndrome of coexisting depression and incident delirium in older hospitalized patients.

DESIGN

Secondary analysis of prospective cohort data from the control group of the Delirium Prevention Trial.

SETTING

General medical service of an academic medical center. Follow-up interviews at 1 month and 1 year post-hospital discharge.

PARTICIPANTS

Four hundred fifty-nine patients aged 70 and older who were not delirious at hospital admission.

MEASUREMENTS

Depressive symptoms assessed at hospital admission using the 15-item Geriatric Depression Scale (cutoff score of 6 used to define depression), daily assessments of incident delirium from admission to discharge using the Confusion Assessment Method, activities of daily living at admission and 1 month postdischarge, and new nursing home placement and mortality determined at 1 year.

RESULTS

Of 459 participants, 23 (5.0%) had the overlap syndrome, 39 (8.5%) delirium alone, 121 (26.3%) depression alone, and 276 (60.1%) neither condition. In adjusted analysis, patients with the overlap syndrome had higher odds of new nursing home placement or death at 1 year (adjusted odds ratio (AOR)=5.38, 95% confidence interval (CI)=1.57-18.38) and 1-month functional decline (AOR=3.30, 95% CI=1.14-9.56) than patients with neither condition.

CONCLUSION

The overlap syndrome of depression and delirium is associated with significant risk of functional decline, institutionalization, and death. Efforts to identify, prevent, and treat this condition may reduce the risk of adverse outcomes in older hospitalized patients.

Delirium in elderly home-treated patients: a prospective study with 6-month follow-up

Delirium usually occurs during hospitalisation. The aims of this study were to evaluate the incidence of delirium in "hospital-at-home" compared to a traditional hospital ward and to assess mortality, hospital readmissions and institutionalisation rates at 6-month follow-up in elderly patients with intermediate/high risk for delirium at baseline according to the criteria of Inouye. We performed a prospective, non-randomised, observational study with 6-month follow-up on 144 subjects aged 75 years and older consecutively admitted to the hospital for an acute illness and followed in a geriatric hospital ward (GHW) or in a geriatric home hospitalisation service (GHHS). Baseline socio-demographic information, clinical data, functional, cognitive, nutritional status, mood, quality of life, and caregiver's stress scores were collected. Of the 144 participants, 14 (9.7%) had delirium during their initial hospitalisation: 4 were treated by GHHS and 10 in a GHW. The incidence of delirium was 16.6% in GHW and 4.7% in GHHS. All delirious patients were very old, with a high risk for delirium at baseline of 60%, according to the criteria of Inouye. In GHW, the onset of delirium occurred significantly earlier and the mean duration of the episode was significantly longer. The severity of delirium tended to be higher in GHW compared to GHHS. At 6-month follow-up, mortality was significantly higher among patients who suffered from an episode of delirium. Moreover, they showed a trend towards a greater institutionalisation rate. GHHS may represent a protective environment for delirium onset in acutely ill elderly patients.

Executive function and depression as independent risk factors for postoperative delirium

BACKGROUND

Postoperative delirium has been associated with greater complications, medical cost, and increased mortality during hospitalization. Recent evidence suggests that preoperative executive dysfunction and depression may predict postoperative delirium; however, the combined effect of these risk factors remains unknown. This study examined the association among preoperative executive function, depressive symptoms, and established clinical predictors of postoperative delirium among 998 consecutive patients undergoing major noncardiac surgery.

METHODS

A total of 998 patients were screened for postoperative delirium (n = 998) using the Confusion Assessment Method as well as through retrospective chart review. Patients underwent cognitive, psychosocial, and medical assessments preoperatively. Executive function was assessed using the Concept Shifting Task, Letter-Digit Coding, and a modified Stroop Color Word Interference Test. Depression was assessed by the Beck Depression Inventory.

RESULTS

Preoperative executive dysfunction (P = 0.007) and greater levels of depressive symptoms (P = 0.049) were associated with a greater incidence of postoperative delirium, independent of other risk factors. Secondary analyses of cognitive performance demonstrated that the Stroop Color Word Interference Test, the executive task with the greatest complexity in this battery, was more strongly associated with postoperative delirium than simpler tests of executive function. Furthermore, patients exhibiting both executive dysfunction and clinically significant levels of depression were at greatest risk for developing delirium postoperatively.

CONCLUSIONS

Preoperative executive dysfunction and depressive symptoms are predictive of postoperative delirium among noncardiac surgical patients. Executive tasks with greater complexity are more strongly associated with postoperative delirium relative to tests of basic sequencing.

Is preoperative anxiety and depression associated with onset of delirium after cardiac surgery in older patients? A prospective cohort study

OBJECTIVES

To investigate the prevalence of preoperative anxiety and depressive symptoms and their relationship with the occurrence of postcardiac delirium and to describe the evolution of these symptoms from preoperative admission until discharge.

DESIGN

Descriptive, prospective, longitudinal study.

SETTING

The intensive care unit and two cardiac surgery units in a university hospital setting.

PARTICIPANTS

One hundred four patients (median age 71; 78.8% men) admitted for elective cardiac surgery.

MEASUREMENTS

Anxiety measured preoperatively using the State-Trait Anxiety Inventory (STAI) and the Hospital Anxiety and Depression Scale (HADS); depression using the HADS; cognitive functioning using the Mini-Mental State Examination (MMSE); delirium using the Confusion Assessment Method (CAM), the CAM for the Intensive Care Unit (CAMICU), and the Delirium Index (DI); and activities of daily living using the Katz index of activities of daily living (Katz ADL scale). MMSE, CAM/CAM-ICU, and DI were obtained on postoperative Days 1, 3, and 7. On Day 7 and at discharge, the STAI, HADS, and Katz ADL scale were repeated.

RESULTS

Postoperative delirium occurred in 26%; 55.8% reported preoperative state anxiety, 25.2% generalized anxiety, and 15.5% depressive symptoms, but no association was found with delirium occurrence. Based on multivariable analysis, prolonged intubation time (odds ratio (OR)51.10, CI: 1.05-1.15, P5.001) and a low intraoperative lowest body temperature (OR50.86, CI: 0.74-0.99, P5.03) were independent predictors of delirium onset. At discharge, 35.7% and 12.2% of patients reported state anxiety and generalized, and 15.3% reported depressive symptoms.

CONCLUSION

Despite the high prevalence of preoperative anxiety and depressive symptoms in older patients with cardiac surgery, no association was found with postoperative delirium.

Posttraumatic stress disorder in general intensive care unit survivors: a systematic review

OBJECTIVE

Our objective was to summarize and critically review data on the prevalence of posttraumatic stress disorder (PTSD) in general intensive care unit (ICU) survivors, risk factors for post-ICU PTSD and the impact of post-ICU PTSD on health-related quality of life (HRQOL).

METHODS

We conducted a systematic literature review using Medline, EMBASE, Cochrane Library, CINAHL, PsycINFO and a hand-search of 13 journals.

RESULTS

Fifteen studies were eligible. The median point prevalence of questionnaire-ascertained "clinically significant" PTSD symptoms was 22% (n=1,104), and the median point prevalence of clinician-diagnosed PTSD was 19% (n=93). Consistent predictors of post-ICU PTSD included prior psychopathology, greater ICU benzodiazepine administration and post-ICU memories of in-ICU frightening and/or psychotic experiences. Female sex and younger age were less consistent predictors, and severity of critical illness was consistently not a predictor. Post-ICU PTSD was associated with substantially lower HRQOL.

CONCLUSIONS

The prevalence of PTSD in ICU survivors is high and negatively impacts survivors' HRQOL. Future studies should comprehensively address how patient-specific factors (e.g., pre-ICU psychopathology), ICU management factors (e.g., administration of sedatives) and ICU clinical factors (e.g., in-ICU delirium) relate to one another and to post-ICU PTSD. Clinicians caring for the growing population of ICU survivors should be aware of PTSD risk factors and monitor patients' needs for early intervention.