Etiologies of delirium and their relationship to reversibility and motor subtype in cancer patients

A revision of JPOS/JASCC clinical guidelines for delirium in adult cancer patients: a summary of recommendation statements

OBJECTIVE

The Japanese Psycho-Oncology Society and the Japanese Association of Supportive Care in Cancer have recently revised the clinical practice guidelines for delirium in adult cancer patients. This article reports the process of developing the revised guidelines and summarizes the recommendations made.

METHODS

The guidelines were developed in accordance with the Medical Information Network Distribution Service creation procedures. The guideline development group, consisting of multi-disciplinary members, created three new clinical questions: non-pharmacological intervention and antipsychotics for the prevention of delirium and trazodone for the management of delirium. In addition, systematic reviews of nine existing clinical questions have been updated. Two independent reviewers reviewed the proposed articles. The certainty of evidence and the strength of the recommendations were graded using the grading system developed by the Medical Information Network Distribution Service, following the concept of The Grading of Recommendations Assessment, Development, and Evaluation system. The modified Delphi method was used to validate the recommended statements.

RESULTS

This article provides a compendium of the recommendations along with their rationales, as well as a short summary.

CONCLUSIONS

These revised guidelines will be useful for the prevention, assessment and management of delirium in adult cancer patients in Japan.

Influence of dosing pattern of antipsychotics on treatment outcome of delirium in patients with advanced cancer

BACKGROUND

Clinical guidelines recommend antipsychotics for the treatment of delirium; however, there has been no confirmed recommendation regarding their administrating patterns. This study aims to investigate whether different dosing patterns of antipsychotics (single or multiple administrations) influence the outcomes of delirium treatment.

METHODS

This is a secondary analysis of a prospective observational study involving patients with advanced cancer and delirium receiving antipsychotics. The Delirium Rating Scale Revised-98 was administered at baseline and after 72 h of starting pharmacotherapy. Patients were classified into single administration group (received a single dosage within 24 h before the assessment) and multiple administration group (received more than one dosage).

RESULTS

A total of 555 patients (single administration 492 (88.6%); multiple administration 63 (11.4%)) were subjected to analyses. The patients in the multiple administration group were more likely to be male, in psycho-oncology consulting settings, with lower performance status, with hyperactive delirium and with severer delirium symptoms. In the multivariate analysis, single administration was significantly associated with better improvement of delirium (p < 0.01, 95% confidence interval: 1.83-5.87) even after controlling covariates. There were no significant differences in the mean dosages of antipsychotics per day in chlorpromazine equivalent (single administration 116.8 mg/day, multiple administration 123.5 mg/day) and the incidence of adverse events between the two groups.

CONCLUSIONS

In this observational study sample, Delirium Rating Scale severity score improvement in single administration was higher than that seen in multiple administration. There was no difference in adverse events between the two groups.

The prevalence, associated factors, clinical impact, and state of diagnosis of delirium in palliative care patients

PURPOSE

The aim of this study is to establish the prevalence, associated factors, and clinical impact of delirium in newly referred palliative care patients and the percentage of delirium diagnoses missed by primary medical teams.

METHODS

Newly referred palliative care patients were evaluated and were reviewed for possible associated factors of delirium. Univariable and multivariable analysis were used to identify associated factors. Median overall survival and survival curves were analyzed. The percentage of missed diagnosis in IPD patients was identified.

RESULTS

We included 350 palliative care patients. Nearly all patients had cancer diagnosis (96.6%). The overall prevalence of delirium was 44.0%. The independent associated factors of delirium were age ≥ 63 years (adjusted odds ratio [aOR], 7.0; 95% CI, 2.2-22.9), palliative performance scale ≤ 20% (aOR, 54.5; 95% CI, 13.1-228.0), brain metastasis (aOR, 15.6; 95% CI, 3.7-66.7), urinary tract infection (aOR, 18.8; 95% CI, 4.7-75.5), sepsis (aOR, 59.0; 95% CI, 4.4-797.8), hyponatremia (aOR, 8.8; 95% CI, 2.6-29.8), and hypercalcemia (not applicable). Interestingly, opioids and benzodiazepines were not associated with delirium. Delirious patients had significantly shorter survival (median survival 11 days). Delirium diagnoses were missed for 76.1%.

CONCLUSION

Nearly half of the palliative care patients had delirium, which was associated with noticeably short survivals. We identified the independent factors associated with the delirium. Despite having a remarkably high prevalence rate and being a well-known poor prognostic factor, there was still a very high rate of missed delirium diagnoses. Effective, routine, delirium screening of palliative care patients needs to be emphasized.

How do delirium motor subtypes differ in phenomenology and contributory aetiology? a cross-sectional, multisite study of liaison psychiatry and palliative care patients

OBJECTIVES

To investigate whether delirium motor subtypes differ in terms of phenomenology and contributory aetiology.

DESIGN

Cross-sectional study.

SETTING

International study incorporating data from Ireland and India across palliative care, old age liaison psychiatry and general adult liaison psychiatry settings.

PARTICIPANTS

1757 patients diagnosed with delirium using criteria from the Diagnostic and Statistical Manual of Mental Disorders, Fourth edition (DSM IV).

PRIMARY AND SECONDARY OUTCOME MEASURES

Hyperactive, mixed and hypoactive delirium subtypes were identified using the abbreviated version of the Delirium Motor Subtype Scale. Phenomenology was assessed using the Delirium Rating Scale Revised. Contributory aetiologies were assessed using the Delirium Aetiology Checklist (DEC), with a score >2 indicating that the aetiology was likely or definitely contributory.

RESULTS

Hypoactive delirium was associated with dementia, cerebrovascular and systemic infection aetiologies (p<0.001) and had a lower overall burden of delirium symptoms than the other motor subtypes. Hyperactive delirium was associated with younger age, drug withdrawal and the DEC category other systemic aetiologies (p<0.001). Mixed delirium showed the greatest symptom burden and was more often associated with drug intoxication and metabolic disturbance (p<0.001). All three delirium motor subtypes had similar levels of impairment in attention and visuospatial functioning but differed significantly when compared with no subtype (p<0.001).

CONCLUSIONS

This study indicates a pattern of aetiology and symptomatology of delirium motor subtypes across a large international sample that had previously been lacking. It serves to improve our understanding of this complex condition and has implications in terms of early detection and management of delirium.

JPOS/JASCC clinical guidelines for delirium in adult cancer patients: a summary of recommendation statements

BACKGROUND

The Japanese Psycho-Oncology Society and Japanese Association of Supportive Care in Cancer recently launched the clinical practice guidelines for delirium in adult cancer patients. The aim of the guidelines was to provide evidence-based recommendations for the clinical assessment and management of delirium in cancer patients. This article reports the process of developing the guideline and summarizes the recommendations made.

METHODS

The guidelines were developed in accordance with the Medical Information Network Distribution Service creation procedures. The guideline development group, consisting of multidisciplinary members, formulated nine clinical questions. A systematic literature search was conducted to identify relevant articles published prior to through 31 May 2016. Each article was reviewed by two independent reviewers. The level of evidence and the strength of the recommendations were graded using the grading system developed by the Medical Information Network Distribution Service, following the concept of The Grading of Recommendations Assessment, Development and Evaluation system. The modified Delphi method was used to validate the recommendation statements.

RESULTS

This article provides a summary of the recommendations with rationales for each, as well as a short summary.

CONCLUSIONS

These guidelines will support the clinical assessment and management of delirium in cancer patients. However, additional clinical studies are warranted to further improve the management of delirium.

Outcome Differences by Delirium Motor Subtype in Patients with Ischemic Stroke

OBJECTIVE

This study evaluated the outcomes of ischemic stroke patients according to delirium motor subtype.

METHODS

This study included patients who were admitted to the stroke unit between August 2017 and March 2019 and met the DSM-5 diagnostic criteria for delirium. Patients were assessed twice weekly throughout their delirium episodes using the Korean version of the Delirium Motor Subtype Scale (K-DMSS) and the Korean version of the Delirium Rating Scale-Revised-98 (K-DRS-98). The clinical characteristics and short-term outcomes of the patients were also assessed.

RESULTS

A total of 943 stroke patients were included; the rate of incident delirium was 10.18%. Of the 95 delirium patients, 34 were classified as the hyperactive subtype, 30 as the mixed subtype, 25 as the hypoactive and six as no subtype. Among the subtype groups, the hypoactive subtype had the highest initial scores on the National Institutes of Health Stroke Scale (NIHSS; 6.72±4.75, p=0.02) and the modified Rankin Scale (mRS; 3.96±1.24, p<0.01). Additionally, the mixed and hypoactive subtypes had longer durations (p<0.01) and more severe symptoms of delirium (p=0.03) than the other motor subtypes, and the hypoactive subtype group had a significantly longer hospital stay (36.88±27.71 days, p<0.01) than the other subtype groups. After adjusting for baseline covariates in a multiple linear regression analysis, these differences remained significant.

CONCLUSION

The present results suggest that the motor subtype of delirium is associated with different characteristics and outcomes in ischemic stroke patients.

A Scoping Review to Map Empirical Evidence Regarding Key Domains and Questions in the Clinical Pathway of Delirium in Palliative Care

CONTEXT

Based on the clinical care pathway of delirium in palliative care (PC), a published analytic framework (AF) formulated research questions in key domains and recommended a scoping review to identify evidence gaps.

OBJECTIVES

To produce a literature map for key domains of the published AF: screening, prognosis and diagnosis, management, and the health-related outcomes.

METHODS

A standard scoping review framework was used by an interdisciplinary study team of nurse- and physician-delirium researchers, an information specialist, and review methodologists to conduct the review. Knowledge user engagement provided context in refining 19 AF questions. A peer-reviewed search strategy identified citations in Medline, PsycINFO, Embase, and CINAHL databases between 1980 and 2018. Two reviewers independently screened records for inclusion using explicit study eligibility criteria for the population, design, delirium diagnosis, and investigational intent.

RESULTS

Of 104 studies reporting empirical data and meeting eligibility criteria, most were conducted in patients with cancer (73.1%) and in inpatient PC units (52%). The most frequent study design was a one or more group, nonrandomized trial or cohort (67.3%). Evidence gaps were identified: delirium risk prediction; comparative effectiveness and harms of prevention, variability in delirium management across PC settings, advanced directive and substitute decision-maker input, and transition of care location; and estimating delirium reversibility. Future rigorous primary studies are required to address these gaps and preliminary concerns regarding the quality of extant literature.

CONCLUSION

Substantial evidence gaps exist, providing opportunities for future research regarding the assessment, prognosis, and management of delirium in PC settings.

Do the Phenotypes of Symptom Fluctuation Differ Among Motor Subtypes in Patients With Delirium?

CONTEXT

Fluctuation in symptoms is a core feature of delirium. However, it is not well known whether the fluctuating nature would differ or not among the delirium subtype groups.

OBJECTIVE

This study compared phenotypes of diurnal fluctuation among different delirium subtypes using a prospective design.

METHODS

The motor subtypes of delirium patients were determined using the Delirium Motor Subtype Scale, fluctuations in consciousness levels were monitored with the Richmond Agitation-Sedation Scale (RASS), and symptom severity was assessed with the Nursing Delirium Screening Scale (Nu-DESC). All scales were administered at three time points over 24 hours; fluctuations in and phenotypes of symptoms were compared according to subtype of delirium using repeated-measures analysis of variance after adjustment for covariates.

RESULTS

This study included 224 delirium patients. Of this patients, 144 (64.3%) were classified as hyperactive, 25 (11.2%) as hypoactive, 33 (14.7%) as mixed, and 22 (9.9%) as no subtype. Scores on the RASS and Nu-DESC significantly changed during the evening and/or night and there were significant subtype group × time interaction for the RASS and Nu-DESC (F = 9.66, P < 0.001 and F = 5.11, P < 0.001, respectively). Post hoc analyses revealed that the hyperactive and mixed subtype groups had higher mean RASS scores and greater ranges of fluctuation than the other groups. The mixed subtype group was differentiated from hyperactive and hypoactive subtype groups by the range of fluctuation in psychomotor activity.

CONCLUSIONS

The phenotypes of symptom fluctuation differed among the motor subtypes. These findings further support the rationale that fluctuations are a core feature of delirium and could differentiate delirium subtypes.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Palliative care and nursing support for patients experiencing dyspnoea

To investigate the association between the type of support provided by nurses for dyspnoea and palliative care practice in Japan, a cross-sectional questionnaire survey was conducted in 2015. Of the 535 questionnaires sent to nurses working at 22 designated cancer hospitals, 344 were returned. The questionnaire assessed the demographic characteristics of the nurses, nursing support for dyspnoea, and palliative care practice measured by the 'Palliative care self-reported practices scale'. Multivariate analysis showed that the domains of palliative care practice influenced the provision of nursing support for patients with dyspnoea. In conclusion, palliative care practice is important for supporting patients with dyspnoea, and nurses should possess the requisite knowledge and skills to deliver this care appropriately.

Comparative Study of Delirium in Emergency and Consultation Liaison- A Tertiary Care Hospital Based Study in Northern India

INTRODUCTION

Delirium is an acute and often fluctuating disturbance in level of consciousness and thought process (cognition) that develops over a short period of time and is a significant change from previous level of functioning. Its prevalence increases with age, complexity of medical co- morbidities and number of medications prescribed.

AIM

To compare the cause and severity of delirium in patients in emergency and consultation liaison psychiatry group.

MATERIALS AND METHODS

A cross-sectional, tertiary care hospital based study was conducted on the patients who presented with delirium from emergency department (50) and consultation-liaison psychiatry groups (50), over a period of one year. The diagnosis was made on the basis of DSM- 5 criteria. The Delirium Rating Scale (DRS-R-98) was applied to know the severity of delirium, cognitive and non-cognitive symptoms of delirium in patients. The results were subjected to appropriate statistical analysis.

RESULTS

In emergency group, 42% patients had metabolic abnormalities, while in consultation-liaison, 38% patients had hyponatremia and hypokalemia and the difference was found to be statistically non-significant (p>0.05). In emergency group, 21(42%) patients were diagnosed as delirium due to other medical condition, followed by 13 (26%) and 8(16%) patients, who were diagnosed as delirium due to multiple aetiologies and substance intoxication each respectively. In only 33(66%) cases in consultation liaison group patients had delirium secondary to other medical conditions. As per DRS-R98 Scale, mean severity score was found to be statistically significant (p<0.05) in consultation liaison group as compared to emergency department group (p> 0.05).

CONCLUSION

Delirium is multifactorial aetiological disease, with variable but preventable outcome. Approach should be aimed at finding the treatable causes to reduce morbidity and mortality.

Recent Insights on Prevalence and Corelations of Hypoactive Delirium

Delirium is a complex neuropsychiatric syndrome which is common in all medical settings. It often goes unrecognized due to difficulties in the detection of its hypoactive variant. This review aims to provide an up-to-date account on recent research on hypoactive delirium (HD). Thirty-eight studies, which were conducted in various clinical settings, including the Intensive Care Unit (ICU), were included in this review. Those studies involved recent research that has been published during the last 6 years. Prevalence of HD was found to vary considerably among different settings. HD seems to be more common in critically ill patients and less common in patients examined by consultation-liaison psychiatric services and in mixed patient populations. The presence of HD in ICU patients was associated with higher short- and long-term mortality and other adverse outcomes, but no such association was reported in other settings. Research on other possible associations of HD with clinical variables and on symptom presentation yielded inconclusive results, although there is some evidence for a possible association of HD with benzodiazepine use. There are several methodological issues that need to be addressed by future research. Future studies should examine HD in the primary care setting; treatment interventions should also be the objective of future research.

Prevalence, course and factors associated with delirium in elderly patients with advanced cancer: a longitudinal observational study

OBJECTIVE

The aim of this study was to investigate the prevalence of delirium on admission, the course of delirium during a 2-week period after admission and factors associated with delirium on admission, among elderly patients with advanced cancer.

METHODS

Patients aged ≥ 65 years with incurable lung or gastroenterological cancer and the Eastern Cooperative Oncology Group Performance Status 2 or greater were continuously sampled after admission to a university hospital. Participants were evaluated for DSM-IV-TR delirium by trained psychiatrists and the delirium subtype was assessed using the Delirium Motor Subtype Scale within 4 days after admission and again 2 weeks later. In addition, we assessed associated factors with delirium on admission.

RESULTS

Among 73 eligible patients, complete data were available from 61 on admission and 49 after 2 weeks. Twenty-six patients (43%) met delirium criteria on admission (hypoactive: 58%, unspecified: 35%, hyperactive: 4%, mixed: 4%). Of these, 19 (73%) remained delirious 2 weeks later. Of 35 patients without delirium on admission, 21 (60%) remained delirium-free 2 weeks later and 7(20%) became delirious. Overall, 33/61 (54%) developed delirium at some point during the study. Patients receiving steroids at admission were more likely to have delirium (odds ratio = 5.0; 95% confidence interval = 1.5-16).

CONCLUSIONS

Given the high prevalence of the delirium, all patients with advanced cancer should be screened for delirium both on admission and regularly thereafter. In addition, medical staff should be aware that steroid use on admission is an additional indicator of elevated risk for delirium.

An analytical framework for delirium research in palliative care settings: integrated epidemiologic, clinician-researcher, and knowledge user perspectives

CONTEXT

Delirium often presents difficult management challenges in the context of goals of care in palliative care settings.

OBJECTIVES

The aim was to formulate an analytical framework for further research on delirium in palliative care settings, prioritize the associated research questions, discuss the inherent methodological challenges associated with relevant studies, and outline the next steps in a program of delirium research.

METHODS

We combined multidisciplinary input from delirium researchers and knowledge users at an international delirium study planning meeting, relevant literature searches, focused input of epidemiologic expertise, and a meeting participant and coauthor survey to formulate a conceptual research framework and prioritize research questions.

RESULTS

Our proposed framework incorporates three main groups of research questions: the first was predominantly epidemiologic, such as delirium occurrence rates, risk factor evaluation, screening, and diagnosis; the second covers pragmatic management questions; and the third relates to the development of predictive models for delirium outcomes. Based on aggregated survey responses to each research question or domain, the combined modal ratings of "very" or "extremely" important confirmed their priority.

CONCLUSION

Using an analytical framework to represent the full clinical care pathway of delirium in palliative care settings, we identified multiple knowledge gaps in relation to the occurrence rates, assessment, management, and outcome prediction of delirium in this population. The knowledge synthesis generated from adequately powered, multicenter studies to answer the framework's research questions will inform decision making and policy development regarding delirium detection and management and thus help to achieve better outcomes for patients in palliative care settings.

Incidence and Cause of Delirium in Hospitalized Patients between the Ages of 18 and 56: A Retrospective Chart Review

Background. Delirium is a common and devastating condition which has been well characterized in elderly cancer patients, but little is known about delirium in cancer patients under the age of 65. Aim. A pilot study to explore the incidence and potential causes of delirium in hospitalized advanced cancer patients at the age of 18–56 years. Design. A retrospective chart review using validated instruments was used to examine the charts of hematology-oncology admissions in a large academic institution. Data was collected as to the likelihood of delirium and potential precipitants. Results. Delirium incidence was 29% among advanced cancer patients. The associated precipitants of delirium were multifactorial, the most common being medications and infection. Delirium was more common in patients admitted for either acute symptom management or the presence of a lung malignancy. Patients with delirium demonstrated significantly increased total hospital cost and a borderline significant result for increased mortality compared to those without delirium. Conclusions. Delirium is common in hospitalized advanced cancer patients (age 18–56 years) and the cause is typically multifactorial. Delirium results in a more complicated hospital course and likely increased mortality. Further research is needed to define strategies to prevent and treat this common and distressing condition.

A longitudinal study of motor subtypes in delirium: relationship with other phenomenology, etiology, medication exposure and prognosis

OBJECTIVE

Motor subtypes have promise as a means of identifying clinically relevant delirium subgroups. Little is known about their relationship to etiologies, medication exposure, and outcomes.

METHODS

Consecutive cases of DSM-IV delirium in palliative care patients were assessed twice-weekly throughout their delirium episodes using the Delirium Motor Subtype Scale (DMSS), Delirium Etiology Checklist (DEC) and Delirium Rating Scale Revised-98 (DRS-R98).

RESULTS

100 patients [mean age 70.2 ± 10.5] were assessed on 303 visits [range 2-9]. Over the entire episode, mean DRS-R98 Severity scores were 16.2 ± 5.7. The mean number of etiologies per case was 3.4 ± 1.2. Motor subtypes were no subtype throughout (6%), hypoactive subtype throughout (28%), mixed subtype throughout (18%), hyperactive subtype throughout (10%) and variable subtype (38%). DRS-R98 Total and Severity scales differed significantly across categories (highest in mixed) but only motor, sleep-wake cycle, perceptual and language disturbance items differed. The Generalized Estimating Equations (GEE) approach was used to explore the relationship between subtype profile and symptoms, medication exposure and etiology. This showed that apart from motor items, only delusions, affective lability, metabolic disturbance and CVA related to any subtype. Cross-sectional assessments indicated greater use of benzodiazepine and antipsychotics in hyperactive patients but GEE analyses did not identify major associations between motor subtype and medication exposure. Patients with sustained hypoactive subtype were significantly more likely to die within one month of study entry.

CONCLUSIONS

Motor profile in delirium is relatively consistent over episode course and relates more closely to delirium phenomenology than to etiology or medication exposure. Motor subtypes have comparable disturbance of key diagnostic features such as cognitive and thought process abnormalities. Although mixed subtype is the most phenomenologically intense, hypoactives have the poorest prognosis.

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.

Pre- and post-transplantation risk factors for delirium onset and severity in patients undergoing hematopoietic stem-cell transplantation

PURPOSE

To determine pre- and post-transplantation risk factors for delirium onset and severity during the acute phase of myeloablative hematopoietic stem-cell transplantation (HSCT).

PATIENTS AND METHODS

Ninety adult patients with malignancies admitted to the Fred Hutchinson Cancer Research Center for their first HSCT were assessed prospectively from 1 week before transplantation to 30 days after transplantation. Delirium was assessed three times per week using the Delirium Rating Scale and the Memorial Delirium Assessment Scale. Potential risk factors were assessed by patient self-report, charts, and computerized records. Multivariable analysis of time to onset of a delirium episode was undertaken using Cox proportional hazards regression with time-varying covariates. Analysis for delirium severity was carried out using a linear mixed effects model. Validation and sensitivity analyses were performed on the final models.

RESULTS

Forty-five patients (50%) experienced a delirium episode. Pretransplantation risk factors for onset and higher severity of delirium were higher mean alkaline phosphatase and blood urea nitrogen (BUN) levels. Poorer pretransplantation executive functioning was also associated with higher delirium severity. Higher doses of opioid medications were the only post-transplantation risk factor for delirium onset (hazard ratio, 1.05; 95% CI, 1.02 to 1.08). Higher opioid doses, current and prior pain, and higher BUN levels were post-transplantation risk factors for greater delirium severity (all P < .01).

CONCLUSION

Pre- and post-transplantation factors can assist in identifying patients who are at risk for delirium during myeloablative HSCT and may enable clinical interventions to prevent delirium onset or decrease delirium symptoms.

Factors associated with prolonged delirium: a systematic review

BACKGROUND

Delirium frequently accompanies acute illness. With treatment of the illness, some individuals recover from delirium while for others the symptoms persist. It is not understood why some individuals improve but others do not. The purpose of this paper is to review systematically what is known about the factors associated with the persistence of delirium.

METHODS

A medical literature search was conducted using several bibliographic databases, supplemented by manual searches of the references. English or French studies were included if they compared two groups of delirious individuals in delirium duration or persistence up to six months after the onset of delirium, diagnosed prospectively with the Diagnostic and Statistical Manual of Mental Disorders (DSM) criteria (or a scale derived and validated against the DSM). Information was collected on the association between possible non-therapeutic prognostic variables and delirium persistence.

RESULTS

Twenty-one observational studies were included, in various settings (e.g. mixed medical-surgical, medical or geriatric, surgical, psychiatric, cancer or palliative care units). Variables assessed included patient characteristics (e.g. age, dementia, medical comorbidity, functional status), delirium characteristics (e.g. presence of hypoactive symptoms, delirium severity) and illness characteristics (e.g. severity of illness, and underlying acute illness). Overall, studies suggested that delirium is often persistent at discharge or beyond. Persistence was associated with dementia, increasing numbers of medical conditions, increasing severity of delirium, hypoactive symptoms and hypoxic illnesses.

CONCLUSIONS

Preliminary findings suggest that some factors may identify those at risk for persistent delirium; however, more research is needed.