I CD-10-CM. The name of the substance/medication withdrawal delirium begins with the specific substance (e.g., alcohol) that is presumed to be causing the withdrawal delir- ium. The diagnostic code is selected from substance-specific codes included in the coding note included in the criteria set. When recording the name of the disorder, the comorbid moderate or severe substance use disorder (if any) is listed first, followed by the word ”with,” followed by the substance withdrawal delirium, followed by the course (i.e., acute, persistent), followed by the specifier indicating level of psychomotor activity (i.e., hyper- active, hypoactive, mixed level of activity). For example, in the case of acute hyperactive withdrawal delirium occurring in a man with a severe alcohol use disorder, the diagnosis is F10.231 severe alcohol use disorder with alcohol withdrawal delirium, acute, hyperac- tive. A separate diagnosis of the comorbid severe alcohol use disorder is not given.
Medication-induced delirium. The name of the medication—induced delirium begins with the specific substance (e.g., dexamethasone) that is presumed to be causing the de- lirium. The name of the disorder is followed by the course (i.e., acute, persistent), followed by the specifier indicating level of psychomotor activity (i.e., hyperactive, hypoactive, mixed level of activity). For example, in the case of acute hyperactive medication-induced delirium occurring in a man using dexamethasone as prescribed, the diagnosis is 292.81 (F19.921) dexamethasone-induced delirium, acute, hyperactive.
Regarding course, in hospital settings, delirium usually lasts about 1 week, but some symptoms often persist even after individuals are discharged from the hospital.
Individuals with delirium may rapidly switch between hyperactive and hypoactive states. The hyperactive state may be more common or more frequently recognized and often is associated with medication side effects and drug withdrawal. The hypoactive state may be more frequent in older adults.
The essential feature of delirium is a disturbance of attention or awareness that is accom- or evolving neurocognitive disorder (NCD). The disturbance in attention (Criterion A) is manifested by reduced ability to direct, focus, sustain, and shift attention. Questions must be repeated because the individual’s attention wanders, or the individual may perseverate with an answer to a previous question rather than appropriately shift attention. The indi- vidual is easily distracted by irrelevant stimuli. The disturbance in awareness is mani- fested by a reduced orientation to the environment or at times even to oneself.
The disturbance develops over a short period of time, usually hours to a few days, and tends to ﬂuctuate during the course of the day, often with worsening in the evening and night when external orienting stimuli decrease (Criterion B). There is evidence from the history, physical examination, or laboratory findings that the disturbance is a physiologi- cal consequence of an underlying medical condition, substance intoxication or with- drawal, use of a medication, or a toxin exposure, or a combination of these factors (Criterion E). The etiology should be coded according to the etiologically appropriate sub- type (i.e., substance or medication intoxication, substance withdrawal, another medical condition, or multiple etiologies). Delirium often occurs in the context of an underlying
NCD. The impaired brain function of individuals with mild and major NCD renders them more vulnerable to delirium.