The primary means of assessing whether a patient is delirious in the ICU unit is based on a specialized delirium rating scale. The items on the scale include changes in mental status, diffuse attention, disorganized thinking, and changes in the level of consciousness. Before using the scale for assessment, the physician will take a detailed history of the patient as well as assess his or her pathological state. The assessment of pathological status includes pain, psychological, and sedation and analgesia levels. A combination of factors is used to determine whether the patient is in a state of delirium.