Epidemiology of delirium: an overview of research issues and findings

New-onset delirium during hospitalization in older adults: incidence and risk factors

OBJECTIVE

Delirium is a clinical diagnosis that can occur frequently in hospitalized patients. A retrospective study was completed to identify the incidence of patients aged greater than 65 developing delirium during hospitalization.

METHODS

This study was conducted at a single tertiary care teaching hospital. Charts of discharged patients from November to December 2018 were evaluated and patients less than age 65 or with delirium present on admission were excluded. The search terms altered, delirium, encephalopathy, and confusion were used to identify patients who developed delirium during the hospitalization. Characteristics of the patients with delirium were also collected.

RESULTS

The incidence of new-onset delirium in patients over age 65 during hospitalization was 10%. Patients who developed delirium during their hospital stay were found to have a higher risk of mortality (p = 0.0028) and severity of illness (p = 0.014). A strong correlation between the length of stay (LOS) and incidence of delirium was also noted.

CONCLUSION

The strong correlation between a longer LOS and a higher incidence of delirium should guide the development of new innovative strategies to shorten the LOS and thus reduce the risk of delirium, in high-risk older hospitalized patients.

Delirium and Its Pharmacological Causes in Older People, Part 1

Delirium is a syndrome that can arise from many causes or underlying conditions, and though it has been reported in younger patients, it is more prevalent in older people, though it can occur in other age groups as well. Identifying delirium is challenging in older people because of the coexistence of underlying dementia or depression, which may further complicate the presentation. Drug-induced delirium is one of the major causes of delirium, and evaluation of this potential cause or contribution is an important component of the evaluation process, since it can lead to poor patient outcomes. This article will review the epidemiology, pathophysiology, evaluation, diagnostic process, and causes of delirium in older people, with a focus on the pharmacological causes.

Impact of Religiosity on Delirium Severity Among Critically Ill Shi'a Muslims: A Prospective Multi-Center Observational Study

This study assesses the impact of religiosity on delirium severity and patient outcomes among Shi'a Muslim intensive care unit (ICU) patients. We conducted a prospective observational cohort study in 21 ICUs from 6 Iranian academic medical centers. Delirium was assessed using the Confusion Assessment Method for the ICU (CAM-ICU) tool. Eligible patients were intubated, receiving mechanical ventilation (MV) for ≥ 48 h. Illness severity was assessed using Acute Physiology and Chronic Health Evaluation II (APACHE II) scores. A total of 4200 patients were enrolled. Patient religiosity was categorized as more (40.6%), moderate (42.3%), or less (17.1%) based on responses to patient and surrogate questionnaires. The findings suggest that lower pre-illness religiosity may be associated with greater delirium severity, MV duration, and ICU and hospital LOS. The lower mortality in the less religiosity group may be related in part to a greater proportion of female patients, but it remains unclear whether and to what extent greater religiosity impacted treatment decisions by patients and families. Further investigation is needed to validate and clarify the mechanism of the mortality findings.

Acute Brain Failure: Pathophysiology, Diagnosis, Management, and Sequelae of Delirium

Delirium is the most common psychiatric syndrome found in the general hospital setting, with an incidence as high as 87% in the acute care setting. Delirium is a neurobehavioral syndrome caused by the transient disruption of normal neuronal activity secondary to systemic disturbances. The development of delirium is associated with increased morbidity, mortality, cost of care, hospital-acquired complications, placement in specialized intermediate and long-term care facilities, slower rate of recovery, poor functional and cognitive recovery, decreased quality of life, and prolonged hospital stays. This article discusses the epidemiology, known etiological factors, presentation and characteristics, prevention, management, and impact of delirium.

The Comparative Risk of Delirium with Different Opioids: A Systematic Review

Objective

There is substantial evidence that the use of opioids increases the risk of adverse outcomes such as delirium, but whether this risk differs between the various opioids remains controversial. In this systematic review, we evaluate and discuss possible differences in the risk of delirium from the use of various types of opioids in older patients.

Methods

We performed a search in MEDLINE by combining search terms on delirium and opioids. A specific search filter for use in geriatric medicine was used. Quality was scored according to the quality assessment for cohort studies of the Dutch Cochrane Institute.

Results

Six studies were included, all performed in surgical departments and all observational. No study was rated high quality, one was rated moderate quality, and five were rated low quality. Information about dose, route, and timing of administration of the opioid was frequently missing. Pain and other important risk factors of delirium were often not taken into account. Use of tramadol or meperidine was associated with an increased risk of delirium, whereas the use of morphine, fentanyl, oxycodone, and codeine were not, when compared with no opioid. Meperidine was also associated with an increased risk of delirium compared with other opioids, whereas tramadol was not. The risk of delirium appeared to be lower with hydromorphone or fentanyl, compared with other opioids. Numbers used for comparisons were small.

Conclusion

Some data suggest that meperidine may lead to a higher perioperative risk for delirium; however, high-quality studies that compare different opioids are lacking. Further comparative research is needed.

Electronic supplementary material

The online version of this article (doi:10.1007/s40266-017-0455-9) contains supplementary material, which is available to authorized users.

Interventions for preventing delirium in hospitalised non-ICU patients

BACKGROUND

Delirium is a common mental disorder, which is distressing and has serious adverse outcomes in hospitalised patients. Prevention of delirium is desirable from the perspective of patients and carers, and healthcare providers. It is currently unclear, however, whether interventions for preventing delirium are effective.

OBJECTIVES

To assess the effectiveness of interventions for preventing delirium in hospitalised non-Intensive Care Unit (ICU) patients.

SEARCH METHODS

We searched ALOIS - the Cochrane Dementia and Cognitive Improvement Group's Specialized Register on 4 December 2015 for all randomised studies on preventing delirium. We also searched MEDLINE (Ovid SP), EMBASE (Ovid SP), PsycINFO (Ovid SP), Central (The Cochrane Library), CINAHL (EBSCOhost), LILACS (BIREME), Web of Science core collection (ISI Web of Science), ClinicalTrials.gov and the WHO meta register of trials, ICTRP.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of single and multi- component non-pharmacological and pharmacological interventions for preventing delirium in hospitalised non-ICU patients.

DATA COLLECTION AND ANALYSIS

Two review authors examined titles and abstracts of citations identified by the search for eligibility and extracted data independently, with any disagreements settled by consensus. The primary outcome was incidence of delirium; secondary outcomes included duration and severity of delirium, institutional care at discharge, quality of life and healthcare costs. We used risk ratios (RRs) as measures of treatment effect for dichotomous outcomes; and between group mean differences and standard deviations for continuous outcomes.

MAIN RESULTS

We included 39 trials that recruited 16,082 participants, assessing 22 different interventions or comparisons. Fourteen trials were placebo-controlled, 15 evaluated a delirium prevention intervention against usual care, and 10 compared two different interventions. Thirty-two studies were conducted in patients undergoing surgery, the majority in orthopaedic settings. Seven studies were conducted in general medical or geriatric medicine settings.We found multi-component interventions reduced the incidence of delirium compared to usual care (RR 0.69, 95% CI 0.59 to 0.81; seven studies; 1950 participants; moderate-quality evidence). Effect sizes were similar in medical (RR 0.63, 95% CI 0.43 to 0.92; four studies; 1365 participants) and surgical settings (RR 0.71, 95% CI 0.59 to 0.85; three studies; 585 participants). In the subgroup of patients with pre-existing dementia, the effect of multi-component interventions remains uncertain (RR 0.90, 95% CI 0.59 to 1.36; one study, 50 participants; low-quality evidence).There is no clear evidence that cholinesterase inhibitors are effective in preventing delirium compared to placebo (RR 0.68, 95% CI, 0.17 to 2.62; two studies, 113 participants; very low-quality evidence).Three trials provide no clear evidence of an effect of antipsychotic medications as a group on the incidence of delirium (RR 0.73, 95% CI, 0.33 to 1.59; 916 participants; very low-quality evidence). In a pre-planned subgroup analysis there was no evidence for effectiveness of a typical antipsychotic (haloperidol) (RR 1.05, 95% CI 0.69 to 1.60; two studies; 516 participants, low-quality evidence). However, delirium incidence was lower (RR 0.36, 95% CI 0.24 to 0.52; one study; 400 participants, moderate-quality evidence) for patients treated with an atypical antipsychotic (olanzapine) compared to placebo (moderate-quality evidence).There is no clear evidence that melatonin or melatonin agonists reduce delirium incidence compared to placebo (RR 0.41, 95% CI 0.09 to 1.89; three studies, 529 participants; low-quality evidence).There is moderate-quality evidence that Bispectral Index (BIS)-guided anaesthesia reduces the incidence of delirium compared to BIS-blinded anaesthesia or clinical judgement (RR 0.71, 95% CI 0.60 to 0.85; two studies; 2057 participants).It is not possible to generate robust evidence statements for a range of additional pharmacological and anaesthetic interventions due to small numbers of trials, of variable methodological quality.

AUTHORS' CONCLUSIONS

There is strong evidence supporting multi-component interventions to prevent delirium in hospitalised patients. There is no clear evidence that cholinesterase inhibitors, antipsychotic medication or melatonin reduce the incidence of delirium. Using the Bispectral Index to monitor and control depth of anaesthesia reduces the incidence of postoperative delirium. The role of drugs and other anaesthetic techniques to prevent delirium remains uncertain.

Diagnostic and treatment practices of delirium in a general hospital

BACKGROUND

Despite the increase in research on delirium, it remains underdiagnosed and difficult to manage, and the outcome is poor especially in older people.

AIMS

To identify the clinically diagnosed rates of delirium, the possible aetiologies, to describe treatment, number and type of psychotropic medication used and to investigate the reasons for referral to a liaison psychiatric team.

METHODS

Retrospective study of medical records of inpatients admitted to Sligo Regional Hospital during an 18-month period.

RESULTS

One hundred and fifty-six files had a documentation of delirium (time prevalence 2%). Mean age of the sample was 82 years (SD = 7.2), 66 (42%) were male. Sixty-nine (44.2%) of the total sample had a previous history of dementia, and 57 (36.5%) had a previous history of delirium. In 67 (43.2%) samples, the cause was infection, while in 4, no specific cause was identified. Ninety (58%) were referred to the liaison service, but only in 26 (28.9 %), the reason for referral was "acute confusion" or "delirium". In a majority of referrals, the reason was an affective disorder more often depression. There were no significant differences between delirium subtypes and referrals (χ(2) = 3.868, df 3, p = 0.28). Examination of the amount of antipsychotics prescribed before, during and after delirium shows that there was a significant increase in use during the delirium (χ(2) = 17.512, df 8, p = 0.025) and decrease in z-hypnotics medication (zopiclone/zolpidem), (χ(2) = 20.114, df 4, p < 0.001), while benzodiazepines and antidepressants remained the same.

CONCLUSIONS

Delirium is often misdiagnosed and unrecognized in hospital settings; however, when identified the pharmacological management is appropriate.

Delirium in the hospitalised elderly: An audit of NCHD prescribing practice

Objectives: This study was carried out to determine the prescribing of psychotropic medication of non-consultant hospital doctors in the management of delirium and to compare this with best practice guidelines.

Method: A structured questionnaire was forwarded to all non-consultant hospital doctors (n = 95) working at St Vincent's University Hospital and data was collected over a six month period. The questionnaire addressed type, dose and route of psychotropic medication use in delirium as well as adjunctive measures used to manage delirium.

Results: There was a 55% response rate (n = 52). Haloperidol and lorazepam were the two most frequently prescribed psychotropic agents used and over one third of respondents (n = 20) reported the use of risperidone. There was wide variation in doses used and a substantial proportion of NCHDs used higher than recommended starting doses for elderly patients with delirium. In addition, the intramuscular route was reported as the commonest route of administration with a majority of respondents reporting infrequent intravenous route of administration.

Conclusions: The drug choice reported by respondents followed best practice guidelines. However, the wide variation in drug doses used and frequency of parenteral route of administration (particularly intramuscular) indicate the need for increasing awareness of best practice international guidelines. Guidance and clarification regarding the use of atypical antipsychotic medication is required following concerns about their use in dementia.

Prevalence and risk factors of postoperative delirium in patients undergoing open heart surgery in northwest of iran

INTRODUCTION

Delirium as a relatively common complication following cardiac surgery remains a contributory factor in postoperative mortality and an obstacle to early discharge of patients.

METHODS

In the present study 329 patients who underwent open heart surgery between 1st January 2008 to 1st January 2009 in Shahid Madani Heart Center, Tabriz, Iran were enrolled.

RESULTS

Overall 4.9% of patients developed delirium after cardiac surgery. We found atrial fibrillation (P = 0.005), lung diseases (P = 0.04) and hypertension (P = 0.02) to be more common in patients who develop delirium postoperatively. Furthermore, the length of intensive care unit (ICU) stay, cardiopulmonary bypass (CPB) time, and ventilation period were also significantly increased. Also a statistically meaningful relationship between the female gender and development of delirium was also noted (P = 0.02). On the other hand no meaningful relationship was detected between diabetes, history of cerebral vascular diseases, peripheral vascular diseases, myocardial infarction, development of pneumonia following surgery, and laboratory levels of sodium, potassium, glucose, and complete blood cell count (CBC) including white blood cells, red blood cells, platelets in the blood-hemoglobin and hematocrits. Also environmental factors like presence of other patients or companion with the patient, and objects like clock, window and calendar in the patient's room did not affect prevention of delirium.

CONCLUSION

Based on this and other investigations, it can be suggested to use MMPI test to recognize pathologic elements to prevented delirium after surgery and complementary treatment for coping with delirium.

Epidemiology and risk factors for delirium across hospital settings

Delirium is one of the most common causes of acute end-organ dysfunction across hospital settings, occurring in as high as 80% of critically ill patients that require intensive care unit (ICU) care. The implications of this acute form of brain injury are profound. Across many hospital settings (emergency department, general medical ward, postoperative and ICU), a patient who experiences delirium is more likely to experience increased short- and long-term mortality, decreases in long-term cognitive function, increases in hospital length of stay and increased complications of hospital care. With the development of reliable setting-specific delirium-screening instruments, researchers have been able to highlight the predisposing and potentially modifiable risk factors that place patients at highest risk. Among the large number of risk factors discovered, administration of potent sedative medications, most notably benzodiazepines, is most consistently and strongly associated with an increased burden of delirium. Alternatively, in both the hospital and ICU, delirium can be prevented with the application of protocols that include early mobility/exercise. Future studies must work to understand the epidemiology across settings and focus upon modifiable risk factors that can be integrated into existing delirium prevention and treatment protocols.

Withdrawal syndrome after donepezil cessation in a patient with dementia

We describe a 62-year-old female diagnosed with Alzheimer’s disease, who had been treated with donepezil for approximately 1 year. When she developed a low-grade fever and digestive complaints, her family physician interpreted these symptoms as side effects of the drug and ordered donepezil to be discontinued. Not only was there no improvement of the somatic symptoms after discontinuation of donepezil, but there was also a worsening of the dementia symptoms, culminating in delirium. When donepezil was re-prescribed, the delirium resolved and the patient’s mental state stabilized. The authors urge great caution in discontinuing treatment with acetylcholinesterase inhibitors such as donepezil.

Delirium: a review

Delirium affects a diverse patient population, may present with highly variable clinical features, is a source of distress for patients and their caregivers, prolongs hospital stays and may herald a poor prognosis. Many cases of delirium are reversible and therefore a full history, physical examination and investigations should be performed. Ahigh degree of suspicion is required for detecting delirium and thorough investigations are necessary in order to determine the underlying etiology and to maximize the potential for reversibility. The following review outlines important aspects of a clinical approach to delirium, the differential diagnosis of delirium, investigation of a patient presenting with delirium, management of delirium, the pathophysiology of delirium and the prognosis accompanying delirium.

Persistent delirium in older hospital patients

PURPOSE OF REVIEW

There are two contradictory views on the prognosis of delirium in older hospital patients. On one hand, the Diagnostic and Statistical Manual, 4th Text Revision (DSM-IV-TR), describes delirium as a transient cognitive disorder, the majority of affected individuals having a full recovery. On the other hand, longitudinal studies of delirium in this population report that the outcomes are poor. This review proposes to reconcile these two contradictory views.

RECENT FINDINGS

In older hospital patients, delirium appears to persist in 44.7% of patients at discharge and in 32.8, 25.6 and 21% of patients at 1, 3 and 6 months, respectively. The outcomes (cognition, function, nursing home placement, mortality) of patients with persistent delirium are consistently worse than the outcomes of patients who recover from delirium.

SUMMARY

The majority of older hospital patients with delirium may recover but the persistence of delirium in a substantial minority of patients may account, in large part, for the poor outcomes of delirium in this population. This proposal has potentially important implications for clinical practice and research.

Delirium, a 'confusing' condition in general hospitals: The experience of a Consultation-Liaison Psychiatry Unit in Greece

BACKGROUND/AIMS

A plethora of studies showed that delirium is common in hospitalized populations. We aimed to examine the characteristics of delirium patients referred to our Consultation-Liaison Psychiatry Unit (CLPU).

METHODS

Our CLPU database was used to obtain data of all referred patients admitted to our hospital and diagnosed with delirium. All referred nondelirious patients served as controls.

RESULTS

During one year, 483 patients were referred to the CLPU. Ninety-three (19.3%) were diagnosed with delirium. Delirious patients were older than nondelirious patients (P < 0.001), with 76.3% aged over 70 years. The majority of the referrals came from surgical specialties. Common etiological factors were fluid and electrolyte imbalance (29%), fractures (28%) and infections (24%), but laboratory tests for the investigation of the etiology prior to the consultation had been performed in only 12 patients (12.9%). The syndrome resulted in prolonged hospitalization and greater use of CLPU services.

CONCLUSIONS

Referrals for delirium are frequent in CLPUs in Greece. Although delirium is common, it remains a 'confusing' condition for health practitioners. The under-diagnosis of delirium, the prolonged hospitalization and the time that the CLPU dedicated to these patients underlines the role of the CLPU psychiatrists in the management of the syndrome.

Prevalence and clinical profile of delirium: a study from a tertiary-care hospital in north India

BACKGROUND

There is scarcity of data from the Indian subcontinent in terms of rates of psychiatric referrals and prevalence of delirium in the medico-surgical setting.

AIM

The present research aimed to study the rates of psychiatric referrals, clinical profile and treatment of delirium in a tertiary-care hospital.

METHODS

The referral register in the department of psychiatry (which records all referrals to the Consultation-Liaison Psychiatry Team) was used to obtain data of all referred patients who had been diagnosed to have delirium while they were admitted in the Nehru Hospital, Postgraduate Institute of Medical Education and Research, Chandigarh, during the period 2000-2005.

RESULTS

Over 6 years, 3092 patients/referrals were received from different wards and included 1050 who were diagnosed as having delirium. The psychiatric referral rate ranged from 0.92% to 1.56% (mean=1.3%) per year; delirium formed the largest diagnostic category (30.77% to 38.95% of all referred cases). The prevalence of delirium in all inpatients ranged from 0.28% to 0.53% (mean=0.44%), with prevalence being higher in the elderly. In 80% of the cases, the referral was for abnormal behavior or patient's noncooperation for treatment. Most of the cases improved with treatment.

CONCLUSIONS

Delirium forms the largest diagnostic category in psychiatry referrals and improves with treatment.

Persistent delirium in older hospital patients: a systematic review of frequency and prognosis

BACKGROUND

one explanation for the poor prognosis of delirium among older hospital patients may be that many of these patients do not recover from delirium. We sought to determine the frequency and prognosis of persistent delirium (PerD) in older hospital patients by systematically reviewing original research on this topic.

METHODS

MEDLINE, EMBASE, PsycINFO and the Cochrane Database of Systematic Reviews were searched for potentially relevant articles. The bibliographies of relevant articles were searched for additional references. Eighteen reports (involving 1,322 patients with delirium) met the following seven inclusion criteria: original research published in English or French, prospective study design, study population of at least 20 hospital patients, patients aged 50 years or more, follow-up of at least 1 week, acceptable definition of delirium at enrollment and included at least one assessment for PerD at discharge or later. The methods of each study were assessed according to the six criteria for prognostic studies described by the Evidence-Based Medicine Working Group. Information about the sample origin and size, age, proportion with dementia, criteria for delirium, timing of follow-up assessments, criteria for PerD, proportion with PerD and prognosis of PerD was systematically abstracted from each report, tabulated and combined using standard meta-analysis techniques.

RESULTS

the combined proportions with PerD at discharge, 1, 3 and 6 months were 44.7% (95% CI 26.8%, 63.7%), 32.8% (95% CI 18.4%, 47.2%), 25.6% (95% CI 7.9%, 43.4%) and 21% (95% CI 1.4%, 40.6%), respectively. The outcomes (mortality, nursing home placement, function, cognition) of patients with PerD were consistently worse than the outcomes of patients who had recovered from delirium.

CONCLUSION

PerD in older hospital patients is frequent, appears to be associated with adverse outcomes and may account for the poor prognosis of delirium in this population. These findings have potentially important implications for clinical practice and research.

Delirium in the acute care setting: characteristics, diagnosis and treatment

Delirium is a neurobehavioral syndrome caused by the transient disruption of normal neuronal activity secondary to systemic disturbances. It is also the most common psychiatric syndrome found in the general hospital setting, its prevalence surpassing better known psychiatric disorders. This article reviews the published literature on delirium and addresses the epidemiology, known etiologic factors, presentation and characteristics of delirium, while emphasizing what is known about treatment strategies and prevention. Given increasing evidence that delirium is not always reversible and the many sequelae associated with its development, physicians must do everything possible to prevent its occurrence or shorten its duration, by recognizing its symptoms early, correcting underlying contributing causes, and using treatment strategies proven to help recover functional status.

Nutritional status and delirium in long-term care elderly individuals

Delirium is physiologically plausible in elderly individuals with a poor nutritional status. We explored body composition, serum protein levels, and delirium in a multicenter long-term care study using bioelectrical impedance analysis (BIA). Estimates from the BIA procedure included the body cell mass and fat-free mass (FFM) of nursing home elderly residents (N = 312). Increased delirium was identified in men and women who were leaner and had lower FFM. Clinical surveillance for delirium in frail elderly individuals with low serum albumin levels and polypharmacy is recommended because of their increased likelihood of having drug toxicities for medications with protein-binding properties.

Care coordination for cognitively impaired older adults and their caregivers

Dementia and delirium, the most common causes of cognitive impairment (CI) among hospitalized older adults, are associated with higher mortality rates, increased morbidity and higher health care costs. A growing body of science suggests that these older adults and their caregivers are particularly vulnerable to systems of care that either do not recognize or meet their needs. The consequences can be devastating for these older adults and add to the burden of hospital staff and caregivers, especially during the transition from hospital to home. Unfortunately, little evidence exists to guide optimal care of this patient group. Available research findings suggest that hospitalized cognitively impaired elders may benefit from interventions aimed at improving care management of both CI and co-morbid conditions but the exact nature and intensity of interventions needed are not known. This article will explore the need for improved transitional care for this vulnerable population and their caregivers.

Interventions for preventing delirium in hospitalised patients

BACKGROUND

Delirium is a common mental disorder with serious adverse outcomes in hospitalised patients. It is associated with increases in mortality, physical morbidity, length of hospital stay, institutionalisation and costs to healthcare providers. A range of risk factors has been implicated in its aetiology, including aspects of the routine care and environment in hospitals. Prevention of delirium is clearly desirable from patients' and carers' perspectives, and to reduce hospital costs. Yet it is currently unclear whether interventions for prevention of delirium are effective, whether they can be successfully delivered in all environments, and whether different interventions are necessary for different groups of patients.

OBJECTIVES

Our primary objective was to determine the effectiveness of interventions designed to prevent delirium in hospitalised patients. We also aimed to highlight the quality and quantity of research evidence to prevent delirium in these settings.

SEARCH STRATEGY

We searched the Specialized Register of the Cochrane Dementia and Cognitive Improvement Group on 28th September, 2005. As the searches in MEDLINE, EMBASE, CINAHL and PsycINFO for the Specialized Register would not necessarily have picked up all delirium prevention trials, these databases were searched again on 28th October, 2005. We also examined reference lists of retrieved articles, reviews and books. Experts in this field were contacted and the Internet searched for further references and to locate unpublished trials.

SELECTION CRITERIA

Randomised controlled trials evaluating any interventions to prevent delirium in hospitalised patients.

DATA COLLECTION AND ANALYSIS

Data collection and quality assessment were performed by three reviewers independently and agreement reached by consensus.

MAIN RESULTS

Six studies with a total of 833 participants were identified for inclusion. All were conducted in surgical settings, five in orthopaedic surgery and one in patients undergoing resection for gastric or colon cancer. Only one study of 126 hip fracture patients comparing proactive geriatric consultation with usual care was sufficiently powered to detect a difference in the primary outcome, incident delirium. Total cumulative delirium incidence during admission was reduced in the intervention group (OR 0.48 [95% CI 0.23, 0.98]; RR 0.64 [95% CI 0.37, 0.98]), suggesting a 'number needed to treat' of 5.6 patients to prevent one case. The intervention was particularly effective in preventing severe delirium. In logistic regression analyses adjusting for pre fracture dementia and Activities of Daily Living impairment, there was no reduction in effect size, OR 0.6, but this no longer remained significant [95% CI 0.3,1.3]. There was no effect on the duration of delirium episodes, length of hospital stay, and cognitive status or institutionalisation at discharge. There was also no significant difference in cumulative delirium incidence between treatment and control groups in a sub-group of 50 patients with dementia (RR 0.9 [95% CI 0.59, 1.36]). In another trial of low dose haloperidol prophylaxis, there was no difference in delirium incidence but the severity and duration of a delirium episode, and length of hospital stay were all reduced. We identified no completed studies in hospitalised medical, care of the elderly, general surgery, cancer or intensive care patients. In outcomes, no studies examined for death, use of psychotropic medication, activities of daily living, psychological morbidity, quality of life, carers or staff psychological morbidity, cost of intervention and cost to health care services. Outcomes were only reported up to discharge, with no studies reporting medium or longer-term effects.

AUTHORS' CONCLUSIONS

Research evidence on effectiveness of interventions to prevent delirium is sparse. Based on a single study, a programme of proactive geriatric consultation may reduce delirium incidence and severity in patients undergoing surgery for hip fracture. Prophylactic low dose haloperidol may reduce severity and duration of delirium episodes and shorten length of hospital admission in hip surgery. Further studies of delirium prevention are needed.

Distinguishing delirium and dementia

Delirium and dementia are syndromes with multiple cognitive impairments common to the elderly and to medically ill patients. While strides have been made in recognition of both delirium and dementia, underdiagnosis is common. Delirium and dementia cause great suffering in patients, families and caregivers. Both necessitate further advancement in assessment methods and treatment, especially when they overlap. Differentiating delirium and dementia requires recognizing that both may present with cognitive, behavioral and neuropsychiatric symptoms, but attentional disturbance and acute onset are cardinal discriminators in delirium. Superimposed delirium on dementia presents a particularly vexing problem in terms of recognition, treatment and prognosis. The pathophysiology of delirium results from diffuse cortical dysfunction or impairment in susceptible areas of the cortex and the reticular activating system. The pathophysiology of dementia is varied across dementias although several share histolological features. Treatment for both delirium and dementia includes antipsychotic medications and cholinesterase inhibitors, among others, although the disadvantages of pharmacological treatment are becoming better understood and demand caution. Nevertheless, there is an array of treatments and preventive strategies being explored for dementia, and to a lesser degree for delirium, that hold promise for the future.

Occurrence and outcome of delirium in medical in-patients: a systematic literature review

BACKGROUND

Despite the acknowledged clinical importance of delirium, research evidence for measures to improve its management is sparse. A necessary first step to devising appropriate strategies is to understand how common it is and what its outcomes are in any particular setting.

OBJECTIVE

To determine the occurrence of delirium and its outcomes in medical in-patients, through a systematic review of the literature.

METHOD

We searched electronic medical databases, the Consultation-Liaison Literature Database and reference lists and bibliographies for potentially relevant studies. Studies were selected, quality assessed and data extracted according to preset protocols.

RESULTS

Results for the occurrence of delirium in medical in-patients were available for 42 cohorts. Prevalence of delirium at admission ranged from 10 to 31%, incidence of new delirium per admission ranged from 3 to 29% and occurrence rate per admission varied between 11 and 42%. Results for outcomes were available for 19 study cohorts. Delirium was associated with increased mortality at discharge and at 12 months, increased length of hospital stay (LOS) and institutionalisation. A significant proportion of patients had persistent symptoms of delirium at discharge and at 6 and 12 months.

CONCLUSION

Delirium is common in medical in-patients and has serious adverse effects on mortality, functional outcomes, LOS and institutionalisation. The development of appropriate strategies to improve its management should be a clinical and research priority. As delirium prevalent at hospital admission is a significant problem, research is also needed into preventative measures that could be applied in community settings.

Donepezil in the prevention and treatment of post-surgical delirium

OBJECTIVE

Delirium is a frequent complication of major surgery in older persons. The authors evaluated the possible benefit of donepezil versus placebo in the prevention and treatment of postoperative delirium in an older population without dementia undergoing elective total joint-replacement surgery.

METHODS

A sample of 80 patients participated in this randomized, double-blind, placebo-controlled trial of donepezil. Each participant was evaluated before surgery and then received donepezil or placebo for 14 days before surgery and 14 days afterward. Postoperative delirium was assessed with the Delirium Symptom Interview, Confusion Assessment Method, daily medical record, nurse-observation reviews, and DSM-IV diagnostic criteria for delirium. Subsyndromal delirium was also assessed for each participant.

RESULTS

Delirium, diagnosed by DSM-IV criteria, was found on at least 1 postoperative day in 18.8% of subjects, but there were no significant differences between the donepezil and placebo groups. When delirium was present, it lasted only 1 day, and there was no difference between the groups. Subsyndromal delirium was found on at least 1 postoperative day for 68.8% of subjects, and, when this occurred, lasted 2 days or less, on average. There was no difference between the groups in the occurrence or duration of subsyndromal delirium. There was no difference between the groups in disposition to home or to another facility.

CONCLUSIONS

This pilot study was unable to demonstrate a benefit for donepezil in preventing or treating delirium in a relatively young and cognitively-intact group of elderly patients undergoing elective orthopedic surgery. Furthermore, postoperative delirium was not a major problem in this population.

Incidence, clinical features and subtypes of delirium in elderly patients treated for hip fractures

OBJECTIVE

To describe the incidence, risk factors and clinical features (subtypes) of delirium during the postoperative period after hip fracture surgery in elderly patients.

DESIGN

Prospective study.

METHODS

Thirty-four consecutive patients (9 men and 25 women) were included in this study between June 16 to July 14, 2003. All patients underwent surgery for a fractured neck of femur and were pre- and postoperatively cared for at a combined geriatric/orthopedic ward.

ASSESSMENT

The diagnosis of delirium was based on the criteria of the DSM-IV and the Confusion Assessment Method Scale. Subtypes of delirium were classified according to the criteria proposed by Lipowski: hyperactive-hyperalert (or agitated), hypoactive-hypoalert (somnolent) and mixed delirium.

RESULTS

Fifty-five percent (n = 19) of the 34 patients developed delirium after surgery. The development of delirium was associated with the medication midazolam taken perioperatively. Nine (47%) of the delirious patients had a hyperactive type of delirium; 5 (26%) developed a hypoactive delirium, and 5 (26%) had a mixed type. We did not find any association among subtypes of delirium and clinical features.

CONCLUSIONS

Delirium is a common complication in the postoperative period of elderly patients treated for hip fractures. The use of midazolam in the perioperative period increased the risk of developing postoperative delirium. The hyperactive type of delirium was the most common subtype of delirium.

Multicomponent intervention strategies for managing delirium in hospitalized older people: systematic review

AIM

The aim of this systematic review was to determine the characteristics and efficacy of various multicomponent intervention strategies for delirium in hospitalized older people.

BACKGROUND

Delirium is a common accompaniment to acute illness in hospitalized older people and has greater costs of care concurrent as well as greater morbidity and mortality.

METHODS

A comprehensive search was undertaken involving all major databases (including the Cochrane Library, Medline, Cumulative Index for Nursing and Allied Health Literature and Invert) and reference lists of all relevant papers. Selection criteria were: evaluation of a multicomponent intervention for delirium, inclusion of an operational definition for delirium consistent with the Diagnostic and Statistical Manual of Mental Disorders-criteria, randomized controlled trials, studies with a quasi-experimental design and reporting on primary data. To generate a description of the characteristics of these multicomponent strategies, the components of these programmes were identified and categorized. Effects on incidence of delirium, cognitive functioning, duration and severity of delirium, functional status, hospital length of stay, and mortality were analysed.

FINDINGS

Three randomized controlled trials, three controlled studies and one before-after study were identified. Intervention strategies to prevent delirium proved to be the most efficacious in reducing its incidence, both with surgical and medical patients. Some additional positive effects of preventive strategies were found on the duration and severity of delirium, and functional status. Conversely, strategies to treat delirium were rather ineffective in older people admitted to medical services. In a population of older people admitted for surgery, however, a shorter duration and a diminished severity of delirium were demonstrated. None of intervention strategies produced beneficial effects on length of stay or mortality.

CONCLUSION

Multicomponent interventions to prevent delirium are the most effective and should be implemented through synergistic cooperation between the various healthcare disciplines. Nurses should play a pivotal role in prevention, early recognition and treatment.

Delirium in inpatients with respiratory diseases

The features of delirium in patients being hospitalized due to respiratory diseases were investigated. From the inpatients in the respiratory medical ward of Tokyo Metropolitan Hiroo General Hospital over the course of 1 year, the patients who had delirium were diagnosed by a semistructured interview. The total number of subjects was 454, and patients with delirium were 43. Various clinical factors were compared between the delirium group and non-delirium group. In the delirium group, there were many elderly patients of 70 years or older. Moreover, there were many patients who had a chronic respiratory disease, patients in which the respiratory diseases were mutually complicated, and patients in whom other diseases combined with the respiratory disease in the delirium group. There were also many patients in the Intensive Care Unit (ICU), and patients with an endotracheal intubation or extubation. Based on the results of a multiple logistic regression analysis, for age, ICU accommodation, and endotracheal intubation, the value of the delirium group was more significant than that of the non-delirium group. In half of the patients from the delirium group, delirium developed within 1 week after hospitalization. In the patients who died in the hospital, however, delirium often developed days after they had been hospitalized. It was suggested that the later developed delirium had a relation to the prognosis.

Challenges in conducting research with acutely ill hospitalized older patients

The older population is the largest consumer of health care, yet little is known about their nursing needs during acute hospitalization. In undertaking a study to address this issue, the researchers faced many challenges that were related to the complexities of researching acutely ill hospitalized older patients. The purpose of the present discussion paper is to present some of the methodological and pragmatic factors that were encountered so that health professionals and researchers can be aware of the potential obstacles when researching this important area, and plan research accordingly. Potential barriers included the complexity of illness in the older person as a result of comorbidity and iatrogenesis; fatigue; normal age-related processes such as visual/hearing impairment; frequent ward transfer or early discharge; delirium or dementia; and high staff turnover resulting in difficulties in coordinating the study. This paper raises the importance of balancing the need to maximize the rigor of research and the needs of participants. Recommendations for future research are made.

The strain of care for Delirium Index: a new instrument to assess nurses’ strain in caring for patients with delirium

This study evaluated content validity, internal consistency and construct validity of the Strain of Care for Delirium Index (SCDI), a newly constructed instrument to measure the strain nurses experience in caring for patients with delirium. Content validity, evaluated by eight experts, reduced the initial pool of items from 38 to 28. Using a convenience sample of 190 nurses, Cronbach's alpha for the 28-item version was 0.88. Using non-linear principal components analysis another eight items were eliminated and a four-factor structure was identified. The proportion of variance explained by the remaining 20 items was 61.51%. Preliminary psychometric evaluation of the SCDI supported content validity, internal consistency and construct validity; however additional psychometric evaluation is warranted.

Predicting post-surgical cognitive disturbance in older Taiwanese patients

The purpose of this study was to test a theoretical model to understand the influences of six predicting variables in post-surgical cognitive disturbance in older Taiwanese patients after elective surgery. The data were collected in a medical center in Taipei, Taiwan. Ninety-three patients were included in the final analysis. The findings showed that cognitive function at admission (beta=0.50, p<0.001), physical function at admission (beta=-0.34, p<0.001), and physiological stability (beta=-0.21, p<0.01) had direct effects on post-surgical cognitive disturbance. Physical function and cognitive function at admission also affected post-surgical cognitive disturbance indirectly through physiological stability. These variables accounted for 67% of the total variance of post-surgical cognitive disturbance. The findings from this study suggest that a careful and systematic assessment of the patient's condition at the time of admission is important. It is necessary to monitor and correct these variables at admission or before surgery to prevent or reduce the impact of post-operative delirium. It is also necessary to monitor these variables during the hospital stay to help nurses to distinguish the etiology of delirium. In each case, knowing when confusion is more likely to occur can assist in focusing more appropriate and effective efforts at detection, thereby reducing the consequences associated with confusion.

Clinical profile of acute confusion in the long-term care setting

Aspects of acute confusion (AC) including risk factors, behavior patterns, and outcomes are not well documented in long-term care (LTC) residents. The purpose of this prospective study was to describe the clinical profile of AC in LTC including risk factors, behavior patterns, etiologies, and 3-month outcomes. Seventy-four elderly LTC residents were assessed for AC, depression, and global cognitive impairment. Risk factors associated with AC included hearing deficits, depression, pulmonary disorders, and abnormal serum sodium or potassium levels. Behavior patterns of acutely confused residents included hyperactive (n = 9, 31%), hypoactive (n = 8, 28%), and mixed (n = 7, 24%). In the majority of the AC cases, the etiology was multIfactorial infections and dehydration were the most common causes. Residents with AC had very poor 3-month outcomes. Thirty-four percent (n = 10) of the residents with AC died within 3 months of the evaluation. This study highlights the complexity and serious nature of AC in this frail population.

Ageing and infection

Average life expectancy throughout developed countries has rapidly increased during the latter half of the 20th century and geriatric infectious diseases have become an increasingly important issue. Infections in the elderly are not only more frequent and more severe, but they also have distinct features with respect to clinical presentation, laboratory results, microbial epidemiology, treatment, and infection control. Reasons for increased susceptibility include epidemiological elements, immunosenescence, and malnutrition, as well as a large number of age-associated physiological and anatomical alterations. Moreover, ageing may be the cause of infection but infection can also be the cause of ageing. Mechanisms may include enhanced inflammation, pathogen-dependent tissue destruction, or accelerated cellular ageing through increased turnover. In most instances, treatment of infection leads to a satisfactory outcome in the elderly. However, in palliative care situations and in patients with terminal dementia, the decision whether or not to treat an infectious disease is becoming a difficult ethical issue.

Immunological mechanisms and the spectrum of psychiatric syndromes in Alzheimer's disease

Pathological, genetic and epidemiological studies support the opinion that inflammatory mechanisms are involved in the pathogenesis of Alzheimer's disease (AD). Recent pathological and neuroradiological (PET) data show that activation of microglia is an early pathogenic event that precedes the process of severe neuropil destruction in AD brains. In this paper we review the evidence that inflammatory mediators can play a pathogenic role in some behavioural disorders frequently encountered during the clinical course in AD patients. Motivational disturbances are the most striking of the depressive symptoms in AD and can be present in a preclinical stage of the disease. Experimental animal studies and clinical trials in humans have shown that cytokines can induce similar symptoms which were described as 'sickness behaviour' or 'depressive-like' state. Delirious states are frequently observed in more advanced stages of dementia. Delirium is generally considered the result of an imbalance in neurotransmitter systems with severe deficits of the cholinergic systems. Animal studies show that pro-inflammatory cytokines, such as interleukin-1, induce a reduced activity of the cholinergic system. In AD, the release of cytokines would exacerbate any already existing disturbances in the cholinergic neurotransmission. This could explain the susceptibility of demented patients to delirium provoked by a wide variety of trivial incidents that are accompanied by an acute phase response. The data reviewed in this paper suggest that it could be worthwhile employing a neuroimmunological approach to study at molecular level the pathogenesis of a broad spectrum of behavioural disturbances common in the clinical course of AD patients.

An open pilot trial of olanzapine for delirium in the Korean population

This study was performed to assess the efficacy and safety of olanzapine for the treatment of delirium in a Korean population. An open trial of olanzapine was conducted in Korean patients with delirium caused by multiple medicosurgical conditions. All subjects were evaluated by Delirium Rating Scale (DRS), which is known to be one of the most sensitive scales for delirium. In addition, other data for profiles of side-effects were collected and analyzed. Twenty patients were treated by olanzapine with doses of 5.9 +/- 1.5 mg/day. The initial dose was 4.6 +/- 0.9 mg/day and maximal dose of olanzapine was 8.8 +/- 2.2 mg/day. The average duration of treatment was 6.6 +/- 1.7 days and the day of maximal response was 3.8 +/- 1.7 treated days. The scores of DRS were significantly improved from 20.0 +/- 3.6 at the time of pretreatment to 9.3 +/- 4.6 at the post-treatment. All subjects showed no definite serious side-effects including anticholinergic and extrapyramidal symptoms. Olanzapine treatment for patients with delirium was effective and safe. This newer drug may be a useful alternative agent to classical antipsychotics in the treatment of delirium.

Delirium: diagnosis, neuropathogenesis, and treatment

Delirium affects more than 2 million patients in the United States each year. The onset of delirium often occurs after hospitalization and in many cases is due to medications or procedures performed during the hospitalization. Unfortunately, delirium remains unrecognized in the majority of patients for several reasons. This review addresses the diagnostic criteria for delirium, the neurochemistry that is believed to be causative, risk factors, measures that may be taken to reduce the onset of delirium, and treatment options.

Detection of delirium using the confusion assessment method

Delirium in hospitalized elderly patients is a phenomenon requiring a lot of nursing attention. It is also a disorder contributing to poor health outcomes in this population. Because of their 24-hour work schedule, nurses are frequently the first to observe acute changes in patients' mental health status and to initiate early interventions. However, delirium is not always easily identified. Therefore, the goal of this article is to increase nurses' knowledge and awareness of early signs of delirium using the Confusion Assessment Method (CAM) routinely and systematically.

Assessing psychiatric illness in geriatric patients

Assessing psychiatric illness in geriatric patients can be difficult for a variety of reasons. First, medical comorbidity may obscure the diagnosis. For example, the patient with multiple chronic illnesses will often have many "vegetative" symptoms of either dementia or depression (e.g., fatigue, loss of energy, poor appetite) attributed to the primary medical condition rather than to an underlying psychiatric illness. Second, the phenomenology of psychiatric illness in the elderly is often different. For example, depression in the elderly is often characterized by prominent anhedonia--loss of interest in virtually everything--and physical complaints leading to an unnecessary medical workup. Third, physicians are often reluctant to diagnose new-onset mental illness in their elderly patients. The fear of stigmatizing the patient or physician discomfort with "psychologic language" often results in underdetection of straightforward psychiatric syndromes. This article will focus primarily on detection of 3 of the most common psychiatric syndromes: dementia, depression, and delirium. The field of geriatric psychiatry has done a good job of characterizing the prevalence (Table I) and clinical features of these syndromes. The problem--briefly addressed here--is how to incorporate some of these findings into a busy clinical practice where there is very little time for the assessment of psychiatric symptoms.

Studying acute confusion in long-term care: clinical investigation or secondary data analysis using the minimum data set?

Clinical investigations of acute confusion have largely been initiated in the acute care setting, where no uniform patient assessment exists. No reliable estimates of the prevalence of acute confusion in long-term care (LTC) residents have been reported. Delirium indicators are present in the nursing home Minimum Data Set (MDS), suggesting that MDS assessments could be used to facilitate studies of acute confusion in LTC. Methods to study acute confusion in LTC are discussed, with an emphasis on the advantages and disadvantages of using secondary analysis of MDS assessments as one research strategy.

Delirium in elderly patients: an overview of the state of the science

Delirium is a common and potentially preventable and reversible cause of functional disability, morbidity, mortality, and increased health care use among elderly individuals. Much has been learned about delirium in the past decade. Highlighted in this article are recent advances in the diagnosis of delirium, delirium in long-term care, use of health care resources, outcomes of delirium, etiologies, and interventions to prevent and treat delirium. Suggestions for future research also are proposed.

Factor analysis supports the evidence of existing hyperactive and hypoactive subtypes of delirium

OBJECTIVE

The aim of this study was to examine whether delirium has specific clinical subtypes.

METHOD

One hundred and eighty-three elderly subjects meeting DSM-IIIR criteria for delirium were evaluated using a 19-item symptom check-list assessing different dimensions of delirium symptomatology. Exploratory factor analysis was conducted in order to examine which symptoms clustered.

RESULTS

Factor analysis confirmed the existence of two different clusters of symptoms: first, symptoms of hyperalert/hyperactive features (agitation, hyper-reactivity, aggressiveness, hallucinations, delusions); and second, symptoms of hypoalert/hypoactive features (decreased reactivity, motor and speech retardation, facial inexpressiveness).

CONCLUSION

This preliminary study seems to support the evidence of hypoactive and hyperactive subtypes of delirium, even though their aetiology and prognostic values need to be further examined.

Outcomes associated with delirium in acutely hospitalized acquired immune deficiency syndrome patients

The study demonstrates that delirium in acquired immune deficiency syndrome (AIDS) patients is associated with mortality, the need for long-term care, and an increased length of hospitalization. Data were collected prospectively on human immunodeficiency virus (HIV)/AIDS patients admitted to a teaching hospital from January 1996 through December 1996. The data included demographic characteristics of the participants, medical diagnoses, CD4 cell count, Karnofsky functional assessment, mortality during admission, length of stay, and discharge placement. Participants were evaluated throughout their hospital stay for evidence of delirium. The presence of delirium was determined using DSM-IV diagnostic criteria. There were no significant differences between delirious and nondelirious patients with respect to demographic characteristics or markers of medical morbidity. Patients with delirium were more likely to die during admission (chi-square [chi2] = 39.1, df = 1, P<.0010), to stay longer in hospital (t = 3.50, df = 12.9, P<.0041), or to need long-term care if discharged alive (chi2 = 12.8, df = 2, P<.0021). Delirium is associated with adverse outcomes in hospitalized AIDS patients. More research is needed to characterize the nature of this association.

Association between delirium and death in AIDS patients

The purpose of this study was to examine the relationship between delirium and death in AIDS patients. Forty-one patients admitted to a combination skilled nursing and assisted-living facility in 1994 were included in the retrospective chart review. Patients were grouped according to the presence versus absence of delirium during the first week of admission. Demographic characteristics and medical morbidity of the two groups were compared using the Chi-square statistic. Kaplan-Meier survival analysis was used to estimate survival functions during the study period for the delirious and nondelirious groups. Nine patients (22%) were found to have an episode of delirium in the first week of admission. There were no significant differences in demographic characteristics or medical morbidity between the delirious and nondelirious groups. Median days from admission to death for those with delirium (10 days) versus those without delirium (135 days) was significantly different (log rank = 19.03; p < 0.0001). Authors concluded that delirium is a marker for decreased survival in this sample of AIDS patients. Future research needs to demonstrate whether improved care of AIDS patients can prevent delirium or limit adverse outcomes associated with it.

Risk factors and incidence of postoperative delirium in elderly Chinese patients

OBJECTIVES

To investigate the incidence of postoperative delirium among elderly patients and to examine the interrelationship between basic vulnerability and precipitating factors for delirium.

DESIGN AND METHODS

This was a prospective cohort study. Data were collected in a tertiary medical center in Taipei, Taiwan. From the 1st to the 5th postoperative day, nurses assessed patients using a confusion-screening tool. Patients with signs of delirium were closely examined for changes in behavior and cognitive status and vital signs, and laboratory data were collected to further validate the organic etiology of delirium. Patients were finally diagnosed according to the DSM-IV criteria in consensus meetings.

SUBJECTS

Seven hundred and one elderly patients, that were admitted consecutively for elective orthopedic or urologic surgery, were enrolled in this study. All subjects met the following criteria: (1) 65 years of age or older; (2) able to communicate orally in Chinese, and (3) not unconscious, delirious, deaf, or aphasic upon admission.

RESULTS

The overall incidence of delirium among these subjects was 5.1%. Logistic regression analysis identified that older age and preexisting cognitive impairment were vulnerability factors, and that the use of psychoactive drugs was a precipitating factor for delirium. Patients with both basic vulnerability and the precipitating factor had a 56-fold increased probability of delirium (0.28 vs. 0.005 in comparison with those who did not exhibit these factors).

CONCLUSION

Few risk factors of postoperative delirium in the older Chinese sample were identified. The only modifiable risk factor appears to be the use of psychoactive drugs.

Delirium: effectiveness of systematic interventions

The purpose of this paper was to review evidence related to the effectiveness of systematic interventions in preventing or detecting and treating delirium. The review process involved a systematic search of the literature on each topic, assessment of the validity of the studies retrieved and examination of their results. The literature search identified 10 studies on prevention and 7 studies on detection and treatment. A broad spectrum of systematic interventions appeared to be modestly effective in preventing delirium in young and old surgical patients but not elderly medical patients. Systematic detection and treatment programs and special nursing care appeared to add large benefits to traditional medical care in young and old surgical patients and modest benefits in elderly medical patients; however, it seemed that the more precise the target of the detection and treatment program, the greater the benefit.