# Delirium : acute state of brain failure - acute encephalopathy to refer to the pathophysiologic state of the central nervous system “process” - delirium should be used to describe the symptoms observed at the bedside - Delirium is an acute change in mental status and must be differentiated from dementia - delirium and dementia frequently coexist because preexisting cognitive failure is a risk factor for delirium. --- ## Screening and Prevention - Many older patients (11%– 40%) have delirium when they are hospitalized or develop it during their admission. Postoperative delirium rates among seniors range from 15%–25% after elective surgery, such as total joint replacement, to more than 50% after high-risk procedures, such as hip fracture repair and cardiac surgery (7–10). Among patients of any age admitted to intensive care units (ICUs) and requiring mechanical ventilatory support, the prevalence of delirium is as high as 80%, and the cumulative incidence at the end of life has been reported as high as 85% (11, 12). - Mounting evidence indicates that delirium is strongly and independently associated with poor patient outcomes. In the hospital, delirium has been associated with a 10-fold increased risk for death and a 3- to 5-fold increased risk for nosocomial complications, prolonged length of stay, and greater need for nursing home placement after discharge For example, a young person who is otherwise healthy may become delirious after having severe sepsis, respi- ratory failure, and mechanical ventilation in the ICU. In contrast, a frail older adult with cognitive impairment may become delirious after taking a low dose of acetaminophen with diphenhydramine for sleep. ---  --- ## When and how should clinicians screen patients for delirium? Although delirium is a common illness, 55%– 80% of cases are unrecognized and undocumented by the treating clinical team  ---  ---  --- ## What elements of the history and physical examination indicate delirium?  ---  ---  --- ## What other disorders should clinicians consider in patients with suspected delirium? Major differential diagnoses of delirium are dementia; depression and other acute psychiatric syndromes; and subsyndromal delirium - can coexist and in some cases are risk factors for one another  --- ## What nonpharmacologic measures are useful? Nonpharmacologic measures are the cornerstone of delirium treatment. The primary therapy for delirium involves identification and treatment of its causative factors. - - Verbal comfort and reassurance by the hospital staff and provision of a companion are preferable to drug therapy. First and foremost, management involves identification and treatment of underlying disease processes as well as removal and reduction of associated contributing factors. - Such factors include psychoactive medications, fluid and electrolyte abnormalities, severe pain, hypoxemia, severe anemia, infections, sensory deprivation, and significant immobility. Particularly in elderly patients, it may not be possible to identify a single cause of delirium. - Because there is a cumulative effect of many vulnerability factors at baseline and acute precipitating factors, small gains in several factors may yield positive results overall. ---  --- ## When nonpharmacologic interventions are insufficient, should clinicians consider drug therapy? If so, which drugs are useful, and what are the adverse effects? There is no medication to treat delirium; rather, there are medications that can cause sedation (for example, antipsychotics) when patients have agitation and other symptoms. - Experts have suggested that the sedative effect of the medications converts the hyperactive/agitated delirium to a more hypoactive form, giv- ing a false sense of positive response. - Of note, hypoactive delirium portends a worse prognosis for the patient. Few head-to-head trials have compared different types of antipsychotics, and it is not clear that one is consistently better than another. In the inpatient setting, trials have shown that haloperidol, when used to treat agitated symptoms of delirium, has efficacy similar to that of atypical antipsychotics. Both atypical and typical antipsychotics have a range of potential adverse effects, including oversedation, QTc prolongation, risk for aspiration, and increased risk for death --- Clinicians must be careful to assess for **akathisia** (motor restlessness), a potential adverse effect of high- potency antipsychotic medications that can be confused with worsen- ing delirium. Haloperidol should be avoided in older persons with parkinsonism and Lewy body disease in favor of an atypical antipsychotic with fewer extrapyramidal effects. --- For critically ill patients in the ICU setting, the risk– benefit ratio of medication adverse effects ver- sus the removal of lines and de- vices often favors pharmacologic treatment. Nevertheless, routine use of antipsychotic medication to prevent or manage delirium is not recommended (39, 40). Recent guidelines suggest optimizing nonpharmacologic strategies and, when sedation is required, using **dexmedetomidine** in mechanically ventilated adults (59). Dexmedetomidine is an **alpha-adrenergic agonist** used for sedation in patients who are intubated and mechanically ventilated in the ICU. Some studies suggest that it can reduce the incidence and duration of ICU delirium, possibly because of its **analgesic** properties, reducing the exposure to higher doses of opiates. Because of this, dexmedetomidine is commonly used as an alternative to benzodiazepines for sedation in criti- cally ill patients In contrast, despite the association of anticholinergic medications with delirium, trials of cholinesterase inhibitors have not shown favorable results --- ## What is the risk for recurrence after an initial episode, and how should clinicians follow patients? In the short term, patients with delirium require continued monitoring of medical, cognitive, and functional status until they return to baseline. The frequency of monitoring depends on the setting and ongo- ing instability. At a minimum, presence and severity should be monitored daily in the hospital; weekly in recently discharged patients, including those admitted to rehabilitation facilities; and monthly upon the patient's return to the community. Medical conditions contributing to delirium may require follow-up testing, such as ensuring correction of electrolyte disturbances, heart failure, and infections. - Cognitive function can be monitored by using measures similar to those for delirium diagnosis. - Assessment of activities of daily living (ADL) is particularly useful for monitoring functional recovery from delirium. Patients whose cognitive or ADL function does not re- turn to baseline 1–2 months after an episode of delirium should be considered for comprehensive geriatrics assessment and/or neuropsychological testing. Minimizing the duration of delir- ium is an important treatment goal. It is thought that the shorter the duration of delirium, the more fully a patient will recover, although it may take weeks to months. Patients with delirium lasting longer than 2 weeks are much less likely to return to base- line function