Delirium in Intensive Care Unit: Phenomenology, Subtypes, and Factor Structure of Symptoms

Face and content validity of a mobile delirium screening tool adapted for use in the medical setting (eDIS-MED): Welcome to the machine

OBJECTIVES

Following a user-centred redesign and refinement process of an electronic delirium screening tool (eDIS-MED), further accuracy assessment was performed prior to anticipated testing in the clinical setting.

METHODS

Content validity of each of the existing questions was evaluated by an expert group in the domains of clarity, relevance and importance. Questions with a Content Validity Index (CVI) <0.80 were reviewed by the development group for potential revision. Items with CVI <0.70 were discarded. Next, face validity of the entirety of the tests was conducted and readability measured.

RESULTS

A panel of five clinical experts evaluated the test battery comprising eDIS-MED. The content validity process endorsed 61 items. The overall scale CVI was 0.92. Eighty-eight per cent of the responses with regard to question relevancy, usefulness and appropriateness were positive. The questions were deemed fifth grade level and very easy to read.

CONCLUSIONS

A revised electronic screening tool was shown to be accurate according to an expert group. A clinical validation study is planned.

Predisposing and Precipitating Factors Associated With Delirium: A Systematic Review

IMPORTANCE

Despite discrete etiologies leading to delirium, it is treated as a common end point in hospital and in clinical trials, and delirium research may be hampered by the attempt to treat all instances of delirium similarly, leaving delirium management as an unmet need. An individualized approach based on unique patterns of delirium pathophysiology, as reflected in predisposing factors and precipitants, may be necessary, but there exists no accepted method of grouping delirium into distinct etiologic subgroups.

OBJECTIVE

To conduct a systematic review to identify potential predisposing and precipitating factors associated with delirium in adult patients agnostic to setting.

EVIDENCE REVIEW

A literature search was performed of PubMed, Embase, Web of Science, and PsycINFO from database inception to December 2021 using search Medical Subject Headings (MeSH) terms consciousness disorders, confusion, causality, and disease susceptibility, with constraints of cohort or case-control studies. Two reviewers selected studies that met the following criteria for inclusion: published in English, prospective cohort or case-control study, at least 50 participants, delirium assessment in person by a physician or trained research personnel using a reference standard, and results including a multivariable model to identify independent factors associated with delirium.

FINDINGS

A total of 315 studies were included with a mean (SD) Newcastle-Ottawa Scale score of 8.3 (0.8) out of 9. Across 101 144 patients (50 006 [50.0%] male and 49 766 [49.1%] female patients) represented (24 015 with delirium), studies reported 33 predisposing and 112 precipitating factors associated with delirium. There was a diversity of factors associated with delirium, with substantial physiological heterogeneity.

CONCLUSIONS AND RELEVANCE

In this systematic review, a comprehensive list of potential predisposing and precipitating factors associated with delirium was found across all clinical settings. These findings may be used to inform more precise study of delirium's heterogeneous pathophysiology and treatment.

Delirium in Older Adults: What a Surgeon Needs to Know

Delirium remains a challenging clinical problem in hospitalized older adults, especially for postoperative patients. This complication, with a high risk of postoperative mortality and an increased length of stay, frequently occurs in older adult patients. This brief narrative paper aims to review the recent literature regarding delirium and its most recent update. We also offer physicians a brief and essential clinical practice guide to managing this acute and common disease.

Does Delirium Phenomenology in Persons with Advanced Cancer Follow a Specific Pattern?

Objective: Recognizing delirium phenomenology (DP) aids the early diagnosis of this syndrome and improves quality of life in patients with advanced cancer. The aim of this study was to identify the neurobehavioral and cognitive patterns of delirium-related symptoms in persons with advanced cancer. Methods: We conducted an observational comparative prospective study on delirium in patients with advanced cancer in different palliative care settings, assessing the presentation/evolution of DP with the Memorial delirium assessment scale (MDAS). Results: Two hundred twenty-seven patients were enrolled on hospital/hospice admission. Of these, 57 were admitted with delirium, 170 without delirium, and 31 developed delirium during hospitalization. Of the 88 patients admitted with delirium or who developed it during hospitalization, only 32 underwent two consecutive MDAS evaluations (at diagnosis and after one week). Delirium resolved in 22 patients (first average MDAS score 10.08 vs. second 3.6 [p < 0.001]). Disorientation, short-term memory, and memory span were altered in all patients with unresolved delirium. The same features were altered in 18 (80%), 17 (80%), and 16 (70%) of the patients with resolved delirium, respectively, and in 58 (35%), 114 (67%), and 38 (23%) of no-delirium patients, respectively. Conclusion: Cognitive-related symptoms appear to be the most prevalent and earliest signs of DP in patients with advanced cancer.

Delirium Research in India: A Systematic Review

Delirium is the most common psychiatric diagnoses encountered in patients with various medical-surgical illnesses, in all the treatment set-ups, with relatively higher incidence and prevalence in the intensive care units. As delirium is encountered in multiple specialties, it is important to understand the research on this diagnosis. This study aims to assess the research output involving patients of delirium from India. A comprehensive search was undertaken using Medline (PubMed) and other databases. Search words included were “delirium,” “delirious,” “delirium tremens” AND “India.” No filters were used. Internet and hand searches yielded 305 articles. Out of these articles, 151 had the terms “delirium,” “delirious,” “delirium tremens” in the title and these were included for the review. Additionally, 14 articles were included for the review, although these did not have these terms in the title, but delirium was one of the major outcome parameters in these studies. Majority of the papers were original articles ( n = 81), and these were followed by, case reports ( n = 58), review articles ( n = 10), letter to the editor (not as case reports but as a communication; n = 13), editorials ( n = 2) and one clinical practice guideline. Most of the original papers have either focused on epidemiology (incidence, prevalence, outcome, etc.), symptom profile, with occasional studies focusing on effectiveness of various pharmacological interventions. There is a dearth of research in the field of delirium from India. There is a lack of studies on biomarkers, evaluation of nonpharmacological interventions, and evaluation of prevention strategies. It is the need of the hour to carry out more studies to further our understanding of delirium in the Indian context.

Abnormal Sleep, Circadian Rhythm Disruption, and Delirium in the ICU: Are They Related?

Delirium is a syndrome characterized by acute brain failure resulting in neurocognitive disturbances affecting attention, awareness, and cognition. It is highly prevalent among critically ill patients and is associated with increased morbidity and mortality. A core domain of delirium is represented by behavioral disturbances in sleep-wake cycle probably related to circadian rhythm disruption. The relationship between sleep, circadian rhythm and intensive care unit (ICU)-acquired delirium is complex and likely bidirectional. In this review, we explore the proposed pathophysiological mechanisms of sleep disruption and circadian dysrhythmia as possible contributing factors in transitioning to delirium in the ICU and highlight some of the most relevant caveats for understanding the relationship between these complex phenomena. Specifically, we will (1) review the physiological consequences of poor sleep quality and efficiency; (2) explore how the neural substrate underlying the circadian clock functions may be disrupted in delirium; (3) discuss the role of sedative drugs as contributors to delirium and chrono-disruption; and, (4) describe the association between abnormal sleep-pathological wakefulness, circadian dysrhythmia, delirium and critical illness. Opportunities to improve sleep and readjust circadian rhythmicity to realign the circadian clock may exist as therapeutic targets in both the prevention and treatment of delirium in the ICU. Further research is required to better define these conditions and understand the underlying physiologic relationship to develop effective prevention and therapeutic strategies.

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

BACKGROUND

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

AIMS AND OBJECTIVES

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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