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.

Ask about neurologic symptoms, such as slurred speech and new-onset weakness; and examine your patient for focal neurologic signs, such as expressive aphasia and hemiparesis because these findings are suggestive of an acute neurologic event.

Now that you suspect delirium, you should confirm the diagnosis using a validated metric, such as the Confusion Assessment Method, or CAM.

Diagnosis requires the presence of an acute and fluctuating change in mental status, poor attention span, and evidence of either disrupted thought processes or alteration in consciousness.

If your patient doesn’t meet these criteria, the CAM is negative, so consider an alternative diagnosis.

On the other hand, if the criteria are met, the CAM is positive, so you can diagnose delirium.

Now that you’ve diagnosed delirium, the next step is to assess the patient's risk of harm to themselves and others.

Patients at low risk will generally present with hypoactive signs of delirium and should generally receive nonpharmacologic management. This includes reducing the dose or discontinuing medications known to have CNS side effects, like opioids; as well as frequent mobilization; and orientation improvement, like providing a clock and calendar so they can keep track of the time and date. Next, ensure proper nutrition and hydration; encourage good sleep hygiene; and minimize sensory deprivation with vision and hearing aids.

On the other hand, patients at high risk of harming themselves and others will generally display hyperactive signs of delirium. These individuals could also try to remove catheters and tubes, and they might even try to leave the hospital.

In this case, start with nonpharmacologic management, including redirection and extra staff attention like a one-to-one sitter.

Additionally, consider pharmacologic management with haloperidol or a second-generation antipsychotic, like olanzapine. Haloperidol is generally a preferred agent since it’s associated with lower risk of side effects, primarily hypotension and oversedation. But, keep in mind that haloperidol is contraindicated in individuals with prolonged QT interval, or neurologic conditions like Parkinson disease and Lewy body dementia.

After initiating management, you should assess the underlying cause. Cover the most common causes of delirium using the PINCH ME mnemonic. To get started, order labs, including a CBC and CMP.

First, let’s start with Pain.

These patients usually report severe pain, or have a potential source of pain, like recent surgery or trauma. Sometimes, your patient could present with hypoactive delirium and diminished speech.

Look for indirect signs of pain, such as grimacing, clenching of the jaw, moaning and groaning, as well as guarding of the affected body part.

In this case, consider poorly controlled pain as a cause of delirium, and be sure to optimize pain control by adjusting doses or switching to alternative medications.

Next up are INfections.

In these individuals, history reveals fever and chills, typically in combination with more specific symptoms associated with the infectious source, like cough or dysuria.

On the other hand, physical exam might show abnormal lung sounds or suprapubic tenderness;