Altered Mental Status/Altered Level of Consciousness

Altered mental status (AMS) is a somewhat vague term. It usually refers to altered level of consciousness (ALC), specifically a depressed level of consciousness or the new onset of confusion. The goal of this essay is to provide guidance in performing an efficient evaluation of the patient with ALC and to avoid expensive (time and money) shot-gunning. The H+PE often points to one or a few specific causes which can then be efficiently ruled in or out.

One study of 317 patients published in Am. J. of Emerg. Med found the following were the causes of AMS in an ED population: Neurologic 28%, Toxic 21%, Traumatic 14%, Psychiatric 14%, Infectious 10%, Endocrine/Metabolic 5%, Pulmonary 3%, Oncologic 3%, CV 1%, Renal 1%, GI 1%.

The high yield causes of ALC include:

Think of the simple things first:

Pitfalls in evaluating patients with ALC