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Intensive Care Medicine Oct 2021Delirium is the most common manifestation of brain dysfunction in critically ill patients. In the intensive care unit (ICU), duration of delirium is independently... (Review)
Review
Delirium is the most common manifestation of brain dysfunction in critically ill patients. In the intensive care unit (ICU), duration of delirium is independently predictive of excess death, length of stay, cost of care, and acquired dementia. There are numerous neurotransmitter/functional and/or injury-causing hypotheses rather than a unifying mechanism for delirium. Without using a validated delirium instrument, delirium can be misdiagnosed (under, but also overdiagnosed and trivialized), supporting the recommendation to use a monitoring instrument routinely. The best-validated ICU bedside instruments are CAM-ICU and ICDSC, both of which also detect subsyndromal delirium. Both tools have some inherent limitations in the neurologically injured patients, yet still provide valuable information about delirium once the sequelae of the primary injury settle into a new post-injury baseline. Now it is known that antipsychotics and other psychoactive medications do not reliably improve brain function in critically ill delirious patients. ICU teams should systematically screen for predisposing and precipitating factors. These include exacerbations of cardiac/respiratory failure or sepsis, metabolic disturbances (hypoglycemia, dysnatremia, uremia and ammonemia) receipt of psychoactive medications, and sensory deprivation through prolonged immobilization, uncorrected vision and hearing deficits, poor sleep hygiene, and isolation from loved ones so common during COVID-19 pandemic. The ABCDEF (A2F) bundle is a means to facilitate implementation of the 2018 Pain, Agitation/Sedation, Delirium, Immobility, and Sleep Disruption in Adult Patients in the ICU (PADIS) Guidelines. In over 25,000 patients across nearly 100 institutions, the A2F bundle has been shown in a dose-response fashion (i.e., greater bundle compliance) to yield improved survival, length of stay, coma and delirium duration, cost, and less ICU bounce-backs and discharge to nursing homes.
Topics: Adult; COVID-19; Critical Care; Critical Illness; Delirium; Humans; Intensive Care Units; Pandemics; SARS-CoV-2
PubMed: 34401939
DOI: 10.1007/s00134-021-06503-1 -
Seminars in Respiratory and Critical... Feb 2021Delirium is a debilitating form of brain dysfunction frequently encountered in the intensive care unit (ICU). It is associated with increased morbidity and mortality,...
Delirium is a debilitating form of brain dysfunction frequently encountered in the intensive care unit (ICU). It is associated with increased morbidity and mortality, longer lengths of stay, higher hospital costs, and cognitive impairment that persists long after hospital discharge. Predisposing factors include smoking, hypertension, cardiac disease, sepsis, and premorbid dementia. Precipitating factors include respiratory failure and shock, metabolic disturbances, prolonged mechanical ventilation, pain, immobility, and sedatives and adverse environmental conditions impairing vision, hearing, and sleep. Historically, antipsychotic medications were the mainstay of delirium treatment in the critically ill. Based on more recent literature, the current Society of Critical Care Medicine (SCCM) guidelines suggest against routine use of antipsychotics for delirium in critically ill adults. Other pharmacologic interventions (e.g., dexmedetomidine) are under investigation and their impact is not yet clear. Nonpharmacologic interventions thus remain the cornerstone of delirium management. This approach is summarized in the ABCDEF bundle (ssess, prevent, and manage pain; oth SAT and SBT; hoice of analgesia and sedation; elirium: assess, prevent, and manage; arly mobility and exercise; amily engagement and empowerment). The implementation of this bundle reduces the odds of developing delirium and the chances of needing mechanical ventilation, yet there are challenges to its implementation. There is an urgent need for ongoing studies to more effectively mitigate risk factors and to better understand the pathobiology underlying ICU delirium so as to identify additional potential treatments. Further refinements of therapeutic options, from drugs to rehabilitation, are current areas ripe for study to improve the short- and long-term outcomes of critically ill patients with delirium.
Topics: Adult; Critical Care; Critical Illness; Delirium; Humans; Intensive Care Units; Pain
PubMed: 32746469
DOI: 10.1055/s-0040-1710572 -
Nature Reviews. Disease Primers Nov 2020Delirium, a syndrome characterized by an acute change in attention, awareness and cognition, is caused by a medical condition that cannot be better explained by a... (Review)
Review
Delirium, a syndrome characterized by an acute change in attention, awareness and cognition, is caused by a medical condition that cannot be better explained by a pre-existing neurocognitive disorder. Multiple predisposing factors (for example, pre-existing cognitive impairment) and precipitating factors (for example, urinary tract infection) for delirium have been described, with most patients having both types. Because multiple factors are implicated in the aetiology of delirium, there are likely several neurobiological processes that contribute to delirium pathogenesis, including neuroinflammation, brain vascular dysfunction, altered brain metabolism, neurotransmitter imbalance and impaired neuronal network connectivity. The Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) is the most commonly used diagnostic system upon which a reference standard diagnosis is made, although many other delirium screening tools have been developed given the impracticality of using the DSM-5 in many settings. Pharmacological treatments for delirium (such as antipsychotic drugs) are not effective, reflecting substantial gaps in our understanding of its pathophysiology. Currently, the best management strategies are multidomain interventions that focus on treating precipitating conditions, medication review, managing distress, mitigating complications and maintaining engagement to environmental issues. The effective implementation of delirium detection, treatment and prevention strategies remains a major challenge for health-care organizations globally.
Topics: Cognitive Dysfunction; Delirium; Humans; Quality of Life
PubMed: 33184265
DOI: 10.1038/s41572-020-00223-4 -
British Journal of Anaesthesia Oct 2020Postoperative delirium is a relatively common and serious complication. It increases hospital stay by 2-3 days and is associated with a 30-day mortality of 7-10%. It is... (Review)
Review
Postoperative delirium is a relatively common and serious complication. It increases hospital stay by 2-3 days and is associated with a 30-day mortality of 7-10%. It is most prevalent in older patients, those with existing neurocognitive disorders, and those undergoing complex or emergency procedures. Preclinical and clinical research in recent years has uncovered more about the pathophysiology of postoperative delirium and may yield more potential therapeutic options. Using the enhanced recovery pathway framework of risk stratification, risk reduction, and rescue treatment, we have reviewed the current clinical evidence on the validity of delirium prediction scores for the surgical population, the effectiveness of perioperative delirium risk reduction interventions, and management options for established delirium. Effective perioperative interventions include depth of anaesthesia monitoring, intraoperative dexmedetomidine infusion, and multimodal analgesia. Choice of general anaesthetic agent may not be associated with significant difference in delirium risk. Several other factors, such as preoperative fasting, temperature control, and blood pressure management have some association with the risk of postoperative delirium; these will require further studies. Because of the limited treatment options available for established delirium, we propose that risk assessment and perioperative risk reduction may be the most effective approaches in managing postoperative delirium.
Topics: Blood Transfusion; Delirium; Fluid Therapy; Humans; Pain Management; Postoperative Complications; Preoperative Care; Risk Assessment; Risk Reduction Behavior
PubMed: 32798069
DOI: 10.1016/j.bja.2020.06.063 -
Wiener Medizinische Wochenschrift (1946) Apr 2022Delirium is the most common acute disorder of cognitive function in older patients. Delirium is life threatening, often under-recognized, serious, and costly. The causes... (Review)
Review
Delirium is the most common acute disorder of cognitive function in older patients. Delirium is life threatening, often under-recognized, serious, and costly. The causes are multifactorial, with old age and neurocognitive disorders as the main risk factors. Etiologies are various and multifactorial, and often related to acute medical illness, adverse drug reactions, or medical complications. To date, diagnosis is clinically based, depending on the presence or absence of certain features. In view of the multifactorial etiology, multicomponent approaches seem most promising for facing patients' needs. Pharmacological intervention, neither for prevention nor for treatment, has been proven effective unanimously. This article reviews the current clinical practice for delirium in geriatric patients, including etiology, pathophysiology, diagnosis, prognosis, treatment, prevention, and outcomes.
Topics: Aged; Delirium; Drug-Related Side Effects and Adverse Reactions; Humans; Prognosis; Risk Factors
PubMed: 35006521
DOI: 10.1007/s10354-021-00904-z -
Nature Reviews. Neurology Oct 2022Delirium and dementia are two frequent causes of cognitive impairment among older adults and have a distinct, complex and interconnected relationship. Delirium is an... (Review)
Review
Delirium and dementia are two frequent causes of cognitive impairment among older adults and have a distinct, complex and interconnected relationship. Delirium is an acute confusional state characterized by inattention, cognitive dysfunction and an altered level of consciousness, whereas dementia is an insidious, chronic and progressive loss of a previously acquired cognitive ability. People with dementia have a higher risk of developing delirium than the general population, and the occurrence of delirium is an independent risk factor for subsequent development of dementia. Furthermore, delirium in individuals with dementia can accelerate the trajectory of the underlying cognitive decline. Delirium prevention strategies can reduce the incidence of delirium and associated adverse outcomes, including falls and functional decline. Therefore, delirium might represent a modifiable risk factor for dementia, and interventions that prevent or minimize delirium might also reduce or prevent long-term cognitive impairment. Additionally, understanding the pathophysiology of delirium and the connection between delirium and dementia might ultimately lead to additional treatments for both conditions. In this Review, we explore mechanisms that might be common to both delirium and dementia by reviewing evidence on shared biomarkers, and we discuss the importance of delirium recognition and prevention in people with dementia.
Topics: Aged; Biomarkers; Cognitive Dysfunction; Delirium; Dementia; Humans; Incidence
PubMed: 36028563
DOI: 10.1038/s41582-022-00698-7 -
Annual Review of Medicine Jan 2022Delirium, an acute disturbance in mental status due to another medical condition, is common and morbid in the intensive care unit. Despite its clear association with... (Review)
Review
Delirium, an acute disturbance in mental status due to another medical condition, is common and morbid in the intensive care unit. Despite its clear association with multiple common risk factors and important outcomes, including mortality and long-term cognitive impairment, both the ultimate causes of and ideal treatments for delirium remain unclear. Studies suggest that neuroinflammation, hypoxia, alterations in energy metabolism, and imbalances in multiple neurotransmitter pathways contribute to delirium, but commonly used treatments (e.g., antipsychotic medications) target only one or a few of these potential mechanisms and are not supported by evidence of efficacy. At this time, the optimal treatment for delirium during critical illness remains avoidance of risk factors, though ongoing trials may expand on the promise shown by agents such as melatonin and dexmedetomidine.
Topics: Critical Care; Critical Illness; Delirium; Humans; Intensive Care Units; Morbidity
PubMed: 34752706
DOI: 10.1146/annurev-med-042220-013015 -
Neurosurgical Review Feb 2022Delirium is a frequent occurring complication in surgical patients. Nevertheless, a scientific work-up of the clinical relevance of delirium after intracranial surgery... (Meta-Analysis)
Meta-Analysis Review
Delirium is a frequent occurring complication in surgical patients. Nevertheless, a scientific work-up of the clinical relevance of delirium after intracranial surgery is lacking. We conducted a systematic review (CRD42020166656) to evaluate the current diagnostic work-up, incidence, risk factors and health outcomes of delirium in this population. Five databases (Embase, Medline, Web of Science, PsycINFO, Cochrane Central) were searched from inception through March 31st, 2021. Twenty-four studies (5589 patients) were included for qualitative analysis and twenty-one studies for quantitative analysis (5083 patients). Validated delirium screening tools were used in 70% of the studies, consisting of the Confusion Assessment Method (intensive care unit) (45%), Delirium Observation Screening Scale (5%), Intensive Care Delirium Screening Checklist (10%), Neelon and Champagne Confusion Scale (5%) and Nursing Delirium Screening Scale (5%). Incidence of post-operative delirium after intracranial surgery was 19%, ranging from 12 to 26% caused by variation in clinical features and delirium assessment methods. Meta-regression for age and gender did not show a correlation with delirium. We present an overview of risk factors and health outcomes associated with the onset of delirium. Our review highlights the need of future research on delirium in neurosurgery, which should focus on optimizing diagnosis and assessing prognostic significance and management.
Topics: Critical Care; Delirium; Humans; Incidence; Intensive Care Units; Neurosurgery
PubMed: 34396454
DOI: 10.1007/s10143-021-01619-w -
JAMA Neurology Nov 2020Delirium is associated with increased hospital costs, health care complications, and increased mortality. Long-term consequences of delirium on cognition have not been... (Meta-Analysis)
Meta-Analysis
IMPORTANCE
Delirium is associated with increased hospital costs, health care complications, and increased mortality. Long-term consequences of delirium on cognition have not been synthesized and quantified via meta-analysis.
OBJECTIVE
To determine if an episode of delirium was an independent risk factor for long-term cognitive decline, and if it was, whether it was causative or an epiphenomenon in already compromised individuals.
DATA SOURCES
A systematic search in PubMed, Cochrane, and Embase was conducted from January 1, 1965, to December 31, 2018. A systematic review guided by Preferred Reporting Items for Systematic Reviews and Meta-analyses was conducted. Search terms included delirium AND postoperative cognitive dysfunction; delirium and cognitive decline; delirium AND dementia; and delirium AND memory.
STUDY SELECTION
Inclusion criteria for studies included contrast between groups with delirium and without delirium; an objective continuous or binary measure of cognitive outcome; a final time point of 3 or more months after the delirium episode. The electronic search was conducted according to established methodologies and was executed on October 17, 2018.
DATA EXTRACTION AND SYNTHESIS
Three authors extracted data on individual characteristics, study design, and outcome, followed by a second independent check on outcome measures. Effect sizes were calculated as Hedges g. If necessary, binary outcomes were also converted to g. Only a single effect size was calculated for each study.
MAIN OUTCOMES AND MEASURES
The planned main outcome was magnitude of cognitive decline in Hedges g effect size in delirium groups when contrasted with groups that did not experience delirium.
RESULTS
Of 1583 articles, data subjected from the 24 studies (including 3562 patients who experienced delirium and 6987 controls who did not) were included in a random-effects meta-analysis for pooled effect estimates and random-effects meta-regressions to identify sources of study variance. One study was excluded as an outlier. There was a significant association between delirium and long-term cognitive decline, as the estimated effect size (Hedges g) for 23 studies was 0.45 (95% CI, 0.34-0.57; P < .001). In all studies, the group that experienced delirium had worse cognition at the final time point. The I2 measure of between-study variability in g was 0.81. A multivariable meta-regression suggested that duration of follow-up (longer with larger gs), number of covariates controlled (greater numbers were associated with smaller gs), and baseline cognitive matching (matching was associated with larger gs) were significant sources of variance. More specialized subgroup and meta-regressions were consistent with predictions that suggested that delirium may be a causative factor in cognitive decline.
CONCLUSIONS AND RELEVANCE
In this meta-analysis, delirium was significantly associated with long-term cognitive decline in both surgical and nonsurgical patients.
Topics: Brief Psychiatric Rating Scale; Cognitive Dysfunction; Delirium; Humans; Observational Studies as Topic; Risk Factors
PubMed: 32658246
DOI: 10.1001/jamaneurol.2020.2273 -
Neurologic Clinics Feb 2022Altered mental status is a nonspecific diagnosis that encompasses a wide spectrum of disease and is frequently cited as a reason for both hospital admission and... (Review)
Review
Altered mental status is a nonspecific diagnosis that encompasses a wide spectrum of disease and is frequently cited as a reason for both hospital admission and inpatient neurologic consultation. There are numerous etiologies of altered mental status, and so although many are facile with the workup of this potentially life-threatening entity, it can nevertheless be overwhelming. Our goal was to provide a practical framework embedded in a current, comprehensive review of the epidemiology, clinical evaluation, and management of undifferentiated altered mental status. We pay particular attention to the management of a critical yet underdiagnosed subtype of altered mental status: delirium.
Topics: Delirium; Humans; Inpatients
PubMed: 34798974
DOI: 10.1016/j.ncl.2021.08.004