Delirium: Clinical sciences

Delirium is a transient and reversible condition characterized by an acute change in consciousness and cognition, as well as a decreased ability to maintain or shift attention.

Delirium is usually seen in older patients, and is always associated with some underlying condition or trigger. The mnemonic “PINCH ME” can help you remember the most common causes of delirium, which include Pain, INfection, Constipation and urinary retention, Hydration, Medications and substances, and finally, Environmental triggers.

Now, if a patient presents with signs and symptoms suggestive of delirium, you should first perform an ABCDE assessment to determine if they are unstable or stable.

If unstable, stabilize their airway, breathing, and circulation. Next, obtain IV access, and, if needed, provide supplemental oxygen to maintain saturation above 90%. Finally, put your patient on continuous vital sign monitoring, including heart rate, blood pressure, and oxygen saturation.

Now let's go back to the ABCDE assessment and discuss stable patients.

First, perform a focused history and physical. Most often, patients are over 65 years old, and might have a history of neurologic conditions like dementia or Parkinson disease. They may present with acute hallucinations, while family members or caregivers often report that the patient has been exhibiting unusual behavior.

Physical examination might reveal hyperactive delirium, with signs like agitation, restlessness, and combativeness.

However, some patients might present with hypoactive delirium, with signs like drowsiness, apathy, withdrawal, or diminished speech.

Finally, some patients can have mixed delirium, switching between hyperactive and hypoactive signs throughout the day.

No matter what type of delirium your patient has, keep in mind that these findings must represent an acute change from baseline, with a fluctuating course described as waxing and waning. If that’s the case, you should suspect delirium.

Now, here’s a clinical pearl to keep in mind! Delirium is a diagnosis of exclusion! In other words, there are no laboratory or imaging methods that can confirm the diagnosis, so be sure and rule out other conditions that can mimic manifestations of delirium.