examinations were ordered, with an overall critical result yield of 8.0%. CT head examinations performed for a complaint of AMS had a yield of 9.8% [25]. A study of 285 febrile elderly patients with AMS showed abnormal brain imaging in 16.5%. The most common neurological diagnoses in patients admitted to the ED were intracranial hemorrhage (ICH) and ischemic stroke [26]. Lower Glasgow Coma Scale, the presence of lateralizing sign, higher systolic blood pressure, and lower body temperature were significantly associated with abnormal brain imaging in febrile elderly patients with AMS [26]. The prevalence of delirium in the ED ranges from 7% to 35%. Four factors with strong associations with ED delirium are nursing home residence, cognitive impairment, hearing impairment, and a history of stroke [27]. There are a wide range of precipitating factors leading to delirium onset that make evaluation challenging, some of which are life threatening. These may be related to systemic disease, such as sepsis or infection, hypoxia, metabolic derangements, hypoglycemia, hyperglycemia, hyponatremia, hypothermia, acute myocardial infarction, neurologic disease including stroke, ICH, Wernicke encephalopathy (thiamine deficiency), central nervous system infection, seizure, surgery, trauma, drugs such as anticholinergic drugs, sedatives, narcotics, drug or alcohol withdrawal, polypharmacy, environmental factors from restraints, stress or pain, and sleep deprivation. There is relatively little evidence in the literature regarding appropriate use of neuroimaging with new onset delirium. CT Head With IV Contrast A common practice is to perform a noncontrast screening head CT followed by a more sensitive MRI brain examination performed with and without IV contrast in the setting of AMS. In the setting of AMS, contrast- enhanced CT examinations can be considered if intracranial infection, tumor, or inflammatory pathologies are suspected.
Altered Mental Status Coma Delirium and Psychosis. examinations were ordered, with an overall critical result yield of 8.0%. CT head examinations performed for a complaint of AMS had a yield of 9.8% [25]. A study of 285 febrile elderly patients with AMS showed abnormal brain imaging in 16.5%. The most common neurological diagnoses in patients admitted to the ED were intracranial hemorrhage (ICH) and ischemic stroke [26]. Lower Glasgow Coma Scale, the presence of lateralizing sign, higher systolic blood pressure, and lower body temperature were significantly associated with abnormal brain imaging in febrile elderly patients with AMS [26]. The prevalence of delirium in the ED ranges from 7% to 35%. Four factors with strong associations with ED delirium are nursing home residence, cognitive impairment, hearing impairment, and a history of stroke [27]. There are a wide range of precipitating factors leading to delirium onset that make evaluation challenging, some of which are life threatening. These may be related to systemic disease, such as sepsis or infection, hypoxia, metabolic derangements, hypoglycemia, hyperglycemia, hyponatremia, hypothermia, acute myocardial infarction, neurologic disease including stroke, ICH, Wernicke encephalopathy (thiamine deficiency), central nervous system infection, seizure, surgery, trauma, drugs such as anticholinergic drugs, sedatives, narcotics, drug or alcohol withdrawal, polypharmacy, environmental factors from restraints, stress or pain, and sleep deprivation. There is relatively little evidence in the literature regarding appropriate use of neuroimaging with new onset delirium. CT Head With IV Contrast A common practice is to perform a noncontrast screening head CT followed by a more sensitive MRI brain examination performed with and without IV contrast in the setting of AMS. In the setting of AMS, contrast- enhanced CT examinations can be considered if intracranial infection, tumor, or inflammatory pathologies are suspected.