Delirium is a common, transient, and in most cases reversible acute neuropsychiatric syndrome. Its core features are global cognitive dysfunction and inattention (Fong, Tulebaev, & Inouye, 2009). It affects people of all ages but is more common amongst the elderly (Alagiakrishnan, 2014). Its overall prevalence in the community is low (1–2%). In hospital settings especially for general admissions, however, its prevalence increases to about 14–24%. Its incidence during an inpatient stay is relatively high ranging from 6% to 56% (Fong, Tulebaev, & Inouye, 2009). This incidence is much higher amongst specialized populations such as patients in intensive-care, subacute, postoperative, and palliative-care settings (Girrard & Ely, 2008). Amongst elderly patients aged over 65 years, the incidence of postoperative delirium is 15-53%. The incidence of delirium for the same patient population in intensive care units (ICU) can reach as high as 70–87% (Inouye, 2006).
The etiologies of the condition are wide and multi-factorial. They frequently reflect the pathophysiological sequel of acute medical conditions, medical complications, or effects of drugs (Fong, Tulebaev, & Inouye, 2009). Delirium develops as a result of complex interaction between several different risk factors. These risk factors include predisposing, non-modifiable factors like serious medical illnesses and pre-existing dementia and precipitating, frequently modifiable factors like infections, taking of sedative drugs, and surgery (Fong, Tulebaev, & Inouye, 2009). Evidence from studies suggests that delirium is correlated with reduced cerebral metabolism or blood flow, inflammation, and cholinergic deficiency (Hshieh, Fong, Marcantonio, & Inouye, 2008).
The presentation of delirium is widely variable and includes signs of disturbance in attention and changes in cognition (Alagiakrishnan, 2014). Consequently, the condition is often undiagnosed or entirely missed. Its clinical diagnosis is based on the presence or absence of given features noted through behavioral observation, clinical history, and cognitive assessment (Fong, Tulebaev, & Inouye, 2009). Current management strategies for the condition focus on prevention as well as management of symptoms. Preventive strategies include avoiding the use of opiod and benzodiapine medications especially amongst elderly patients. Symptom management strategies include both pharmacological and non-pharmacological approaches (Fong, Tulebaev, & Inouye, 2009). Pharmacological approaches are a measure of last resort as the evidence in their favor is controversial. Neuroleptics are the most preferred medications for acute agitation. Other potential treatments for delirium are 5-HT receptor and cholinesterase inhibitors. Non-pharmacological treatment strategies are considered first-line treatments. They include strategies such as reorientation and behavioral interventions (Fong, Tulebaev, & Inouye, 2009).
In summary, this paper has defined the neurocognitive disorder delirium. Further, it has briefly examined its prevalence and incidence in both community and hospital settings. Further, it has described briefly the etiologies of the condition which include predisposing modifiable and non-modifiable risk factors. Also, it has examined how the condition is diagnosed. Finally, it has briefly reviewed current management strategies for treating the condition.
References
Alagiakrishnan, K. (2014). Delirium. Retrieved from http://emedicine.medscape.com/article/288890-treatment.
Fong, T. G., Tulebaev, S. R., & Inouye, S. K. (2009). Delirium in elderly adults: Diagnosis, prevention, and treatment. Nat Rev Neurol., 5(4), 210-220.
Girard, T. D. & Ely, E. W. (2008). Delirium in the critically ill patient. Handb. Clin. Neurol., 90, 39–56.
Hshieh, T. T., Fong, T. G., Marcantonio, E. R., & Inouye, S. K. (2008). Cholinergic deficiency hypothesis in delirium: a synthesis of current evidence. J. Gerontol. A Biol. Sci. Med. Sci., 63:764–772
Inouye, S.K. (2006). Delirium in older persons. N. Engl. J. Med., 354, 1157–1165.
