Altered Mental Status in the Emergency Department

Austin T. Smith, MD; Jin H. Han, MD, MSc


Semin Neurol. 2019;39(1):5-19. 

In This Article

Assessment of Acute Changes in Altered Mental Status

Several clinical scoring systems are used to grade the degree of AMS. These systems are used to standardize and facilitate communication between providers.

The most common scoring systems are the Glasgow Coma Score (GCS) and the AVPU (alert [A], responsive to verbal stimuli [V], responsive to painful stimuli [P], and unresponsive [U]) scale. The GCS assesses the patient's eye opening, verbal and motor responses to stimuli, and ranges from 3 (comatose) to 15 (normal). It was initially developed to describe the physiologic derangement in acute traumatic brain injuries, but the relationship between GCS score and survival is not linear.[20] Additionally, it can be difficult to use reliably if not used regularly.[21] The AVPU scale is a simple scale with four possible outcomes. It stands for alert (A), responsive (R) to verbal stimuli, responsive to painful stimuli (P), and unresponsive (U). While it is easy to remember, it lacks granularity to detect subtle impairments.[22]

Because a patient's level of arousal is often affected with AMS, we recommend using a structured arousal scale such as the Richmond Agitation and Sedation Scale (RASS;[23] Figure 1) to characterize the degree of AMS. The scale ranges from −5 (unresponsive to pain and voice) to +4 (extreme combativeness);[23,24] a score of 0 represents normal and alert.

Several delirium assessments have been developed over the past two decades and are summarized in Table 1. These assessments test both arousal and content. The Confusion Assessment Method (CAM),[25,26] Brief Confusion Assessment Method,[27] Confusion Assessment Method for the Intensive Care Unit,[28] and the RASS have been validated in older ED patients. Delirium affects approximately 10% of older ED patients,[29] and is associated with higher mortality,[30] prolonged hospitalizations,[31] and accelerated cognitive and functional decline.[32–35] More details on delirium in the ED and its assessment can be found at It is important to note that very few delirium assessments have been validated in younger patients, especially in the ED setting.