was derived for assessment of head injury, it is a reasonable means of documenting changes in mentation due to any etiology. Critical tests in the field include glucose level and stroke screen if clinical suspicion warrants. All patients with AMS should be placed on a cardiac monitor with pulse oximetry. Treatment should be administered in the prehospital setting, according to local protocols for the suspected etiology. Figure 6.1 shows a checklist of prehospital considerations most relevant to the management of patients with AMS.
can also classify AMS into the following categories: primary central nervous system (CNS)/structural, metabolic/autoregulatory, toxic/pharmacologic, and infectious. The ED needs to assess and treat readily reversible causes of altered mentation, including hypoglycemia, opioid intoxication, and Wernicke encephalopathy. Rapid treatment prevents clinical deterioration and may prove diagnostic.
TABLE 6.1 Mnemonic “AEIOU-TIPS” for Altered Mental Status
reflex, and does not indicate purposeful movement unless the patient is reliably able to let go of the grasp as well. In addition to motor responses, muscle tone and extremity reflexes should be tested and compared bilaterally. Symmetric findings do not rule out structural causes of altered consciousness, but symmetry does increase the likelihood of a nonstructural source of altered consciousness.
TABLE 6.2 Pupillary Abnormalities and Associated Diseases
LP, even if a CT finding is negative, when clinical signs of increased ICP are present, including GCS <9 or a drop in GCS of 3 or more, relative bradycardia and hypertension, focal neurologic signs, papilledema, abnormal posturing, or unequal, dilated or poorly responsive pupils.7
the prevalence of NCSE in patients with AMS ranged from 8% to 30% (overall prevalence of 21.5%, 95% CI: 18%-25%), suggesting that the prevalence of NCSE is sufficiently high to consider routine use of urgent EEG in select patients.11 A recent portable device that syncs with cloud monitoring and can be applied by any emergency clinician shows promise in providing early diagnostic information.12 In addition, portable, quantitative EEG-based brain function monitoring may provide important diagnostic and functional information on brain injury.13
TABLE 6.3 CSF Studies to Consider in Altered Mental Statusa