Delirium: sifting through the confusion

Classics in Chemical Neuroscience: Deliriant Antihistaminic Drugs

Antihistaminic drugs are widely used clinically and have long been primarily known for their use to treat severe allergic conditions caused by histamine release. Antihistaminic drugs also exert central nervous system (CNS) effects, acting as anxiolytics, hypnotics, and neuroleptics. However, these drugs also have multiple serious neuropharmacological side-effects, inducing delirium, hyperarousal, disorganized behavior, and hallucinations. Due to their robust CNS effects, antihistamines are also increasingly abused, with occasional overdoses and life-threatening toxicity. Here, we discuss chemical and neuropharmacological aspects of antihistaminic drugs in both human and animal (experimental) models and outline their current societal and mental health importance as neuroactive substances.

Preventing and treating delirium in clinical settings for older adults

Delirium is a serious consequence of many acute or worsening chronic medical conditions, a side effect of medications, and a precipitant of worsening functional and cognitive status in older adults. It is a syndrome characterized by fluctuations in cognition and impaired attention that develops over a short period of time in response to an underlying medical condition, a substance (prescribed, over the counter, or recreational), or substance withdrawal and can be multi-factorial. We present a narrative review of the literature on nonpharmacologic and pharmacologic approaches to prevention and treatment of delirium with a focus on older adults as a vulnerable population. Older adult patients are most at risk due to decreasing physiologic reserves, with delirium rates of up to 80% in critical care settings. Presentation of delirium can be hyperactive, hypoactive, or mixed, making identification and study challenging as patients with hypoactive delirium are less likely to come to attention in an inpatient or long-term care setting. Studies of delirium focus on prevention and treatment with nonpharmacological or medication interventions, with the preponderance of evidence favoring multi-component nonpharmacological approaches to prevention as the most effective. Though use of antipsychotic medication in delirium is common, existing evidence does not support routine use, showing no clear benefit in clinically significant outcome measures and with evidence of harm in some studies. We therefore suggest that antipsychotics be used to treat agitation, psychosis, and distress associated with delirium at the lowest effective doses and shortest possible duration and not be considered a treatment of delirium itself. Future studies may clarify the use of other agents, such as melatonin and melatonin receptor agonists, alpha-2 receptor agonists, and anti-epileptics.

Factors that contribute to underrecognition of delirium by registered nurses in acute care settings: a scoping review of the literature to explain this phenomenon

AIMS AND OBJECTIVES

In order to obtain more information regarding this phenomenon, a scoping review of the literature was undertaken to analyse current research on the recognition of delirium by registered nurses in acute care settings.

BACKGROUND

Delirium is often manifested as a sign of an underlying undiagnosed condition that requires immediate intervention and is frequently manifested in acute care settings. Unfortunately, registered nurses often do not recognise delirium and its occurrence goes under-reported.

DESIGN/METHODS

Based on six inclusion criteria, a search in numerous databases using terms such as delirium detection, recognition and diagnosis by registered nurses was undertaken. Eight quantitative studies were deemed relevant and analysed for this scoping review.

RESULTS

Seven major categories emerged: the fluctuating nature of delirium, the impact of delirium education on its recognition, communication barriers, inadequate use of delirium assessment tools, lack of conceptual understanding of delirium, delirium as a burden and the likeness of delirium and dementia. A brief summary of the findings in each category is reported here.

CONCLUSIONS

The scoping review revealed that delirium remains underrecognised by registered nurses, which potentially contributes to reduced quality of nursing care for clients experiencing this condition. Further research on delirium and the processes that registered nurses use to recognise it is timely and will facilitate the development of evidence-based interventions to manage it.

RELEVANCE TO CLINICAL PRACTICE

While acute care registered nurses have historically reported dramatic changes in cognitive and neuro-biological functions in ill older adults, the literature highlighted in this scoping review revealed the following: (1) the need for further research to validate delirium assessment tools and, (2) the need for education and training for registered nurses on the use of these assessment tools to promote early recognition and thereby decrease the incidence of delirium in older adults.

Psychiatric presentations/manifestations of medical illnesses

Psychiatry is clearly an integral part of medicine. With a history and physical exam (called the mental status exam in psychiatry), appropriate laboratory or imaging studies, a differential diagnosis is made. If a specific DSM-IV-TR diagnosis is made, then the treatment will naturally follow. The diagnoses are scientifically established with good validity, specificity, sensitivity and inter-rater reliability. Similarly the treatments are established through scientific research. However, sometimes medical illnesses may present with symptoms seemingly pointing to a psychiatric origin. Making a misdiagnosis can be quite problematic and dangerous for the patient. The opposite is also true, that psychiatric illnesses may present with symptoms implying a medical diagnostic origin. Finally, psychiatric patients may have more than one psychiatric diagnosis and in addition, a medical diagnosis too. A high degree of suspicion should always be entertained by the diagnosing physician, psychiatric or non-psychiatric. This paper reviews the literature regarding these situations and then presents several clinical cases where this conundrum was present. Making the correct diagnosis was critical in the successful treatment outcome of each of the clinical cases. When asked to consult on a patient by non-psychiatric physicians, the psychiatrist must be careful to also look for non-psychiatric origins for the referring symptoms. It is important for psychiatrists to build on their medical knowledge from medical school and internship and continue to be kept abreast of confounding symptomatology.

Delirium in elderly people: a review

The present review aims to highlight this intricate syndrome, regarding diagnosis, pathophysiology, etiology, prevention, and management in elderly people. The diagnosis of delirium is based on clinical observations, cognitive assessment, physical, and neurological examination. Clinically, delirium occurs in hyperactive, hypoactive, or mixed forms, based on psychomotor behavior. As an acute confusional state, it is characterized by a rapid onset of symptoms, fluctuating course and an altered level of consciousness, global disturbance of cognition or perceptual abnormalities, and evidence of a physical cause. Although pathophysiological mechanisms of delirium remain unclear, current evidence suggests that disruption of neurotransmission, inflammation, or acute stress responses might all contribute to the development of this ailment. It usually occurs as a result of a complex interaction of multiple risk factors, such as cognitive impairment/dementia and current medical or surgical disorder. Despite all of the above, delirium is frequently under-recognized and often misdiagnosed by health professionals. In particular, this happens due to its fluctuating nature, its overlap with dementia and the scarcity of routine formal cognitive assessment in general hospitals. It is also associated with multiple adverse outcomes that have been well documented, such as increased hospital stay, function/cognitive decline, institutionalization and mortality. In this context, the early identification of delirium is essential. Timely and optimal management of people with delirium should be performed with identification of any possible underlying causes, dealing with a suitable care environment and improving education of health professionals. All these can be important factors, which contribute to a decrease in adverse outcomes associated with delirium.

Review: delirium in the elderly: a comprehensive review

Delirium is a common neuropsychiatric syndrome in the elderly characterized by concurrent impairments in cognition and behaviors. The etiologies for delirium are often multifactorial and are due to underlying medical illnesses and/or due to medication effect. The diagnosis of delirium is often missed in elderly patients and this condition may be mislabeled as depression or dementia. Untreated, delirium can have devastating consequences in the elderly with high rates of morbidity and mortality. Available evidence indicates that early detection, reduction of risk factors, and better management of this condition can decrease its morbidity rates. In this review, we discuss the etiology, neurobiology, diagnosis, prevention, and treatments for this potentially lethal condition in the elderly.

Surgical intensive care unit (ICU) delirium: a "psychosomatic" problem?

OBJECTIVE

Intensive Care Unit (ICU) delirium is a common complication after major surgery and related among other potential medical precipitants to either pre-existing cognitive impairment or the intensity and length of anesthesiology or the type of surgery. Nevertheless, in some rare situations, an organic etiology is not always found, which can be frustrating for the medical team. Some clinicians working in an intensive care unit have a reluctance to seek another hypothesis in the psychological field.

METHOD

To illustrate this, we report the case of a 59-year-old woman who developed a massive delirium during her intensive care unit stay after being operated on for a left retroperitoneal sarcoma. Interestingly, she had had no previous cognitive disorders and a somatic explanation for her psychiatric disorder could not been found. Just before the surgery, she was grieving the recent loss of a colleague of the same age, and also a close friend, and therefore had a death anxiety.

RESULTS

With this case report, we would like to point out the importance of psychological factors that might precipitate delirium in a predominately somatic environment such as an intensive care unit.

SIGNIFICANCE OF RESULTS

ICU delirium can sometimes be considered as a "psychosomatic" problem with either a stress response syndrome after surgery or a defense mechanism against death anxiety. Clinicians should be aware of the possibility of such psychological factors even if they always must first rule out potential somatic causes for delirium and encourage thorough investigation and treatment of these medical causes. A collaboration with the psycho-oncologist is recommended to better manage this "psychosomatic" problem.