Delirium

Updated January 29, 2024

What this section covers:

What is delirium?
How to recognize delirium
What delirium is like for your loved one
Management and Treatment
Diagnosis and treatment of the underlying illness
Prognosis: what will the future hold for your loved one?
Key points

What is delirium?

A Case

My 86-year-old father was admitted to the hospital because he had trouble breathing, and soon after he was admitted, it was like he went crazy! He didn’t know where he was, and he kept pulling out his I.V. line. He couldn’t understand what the nurses were doing, and he attacked one of them who was trying to take his blood pressure. When I visited, I don’t think he even knew who I was. I thought he was going to have to go to a nursing home when he left the hospital, even though he’d been living independently before all this happened.

Delirium is a syndrome of altered mental state that can come on suddenly. The patient becomes confused and disoriented, may be agitated, and may hallucinate. When delirium occurs, it always means that there is some illness underlying the symptoms, and that illness could be life-threatening.

You can think of delirium as being like an iceberg, with the symptoms you see above the waterline and the much larger and more dangerous part of the condition – the cause -- below the waterline, as shown in the figure below.

Delirium: the changes you see are only the tip of the iceberg.

There is a long list of diseases and conditions that can cause delirium.

Here are some examples:

Infection — pneumonia, Covid-19, urinary tract infection
Heart failure or heart attack (which can otherwise be “silent”)
Use of medications such as Valium, Benadryl, or Percocet
Alcohol withdrawal in a person with serious daily drinking
Surgery with anesthesia
Brain disease: stroke, head injury, tumor, infection

In elderly people, it is often true that there is more than one cause of delirium. For example, a patient may have pneumonia after surgery involving anesthesia. It is even true that many smaller problems can add up to cause a delirium. A simple bladder infection along with dehydration and the use of certain medications can together cause delirium. A common scenario in the nursing home is constipation, mild dehydration, and a single use of a drug like Benadryl.

In most cases, the syndrome of delirium is temporary; the delirious episode resolves when the underlying cause such as pneumonia resolves. In other cases – such as delirium after stroke or head injury – delirium can take months to resolve or even be permanent.

Common drugs can cause delirium in elders

How to recognize delirium

The patient with delirium is not fully aware of what is going on around them. They may become agitated for no apparent reason or when approached. Often, they are easily distracted. At times, their attention turns inward, so they seem to close down and look like they’re sleeping. This quiet state can be misleading because it appears that nothing is wrong.

Usually, delirium develops suddenly, over hours to days. Then symptoms can fluctuate over the course of the day and night, so that sometimes the patient is clear-headed (in a state called a “lucid interval”) and other times they are very muddled or sleepy or hallucinating. When the latter occurs in the evening, it’s called “sundowning.”

Symptoms develop acutely

Symptoms can vary over a 24-hour period

Although sundowning is common, hallucinations can occur at any time of day. They can take several forms:

Visual hallucinations (“seeing things”) are most common in delirium. These are often bizarre and can be frightening.
Auditory hallucinations (“hearing things”) are also common. One patient heard a choir singing outside her hospital room.
Less commonly except in alcohol withdrawal and drug-induced delirium, patients can experience tactile (touch)
Others may smell odd things like rotten eggs (olfactory hallucinations)

Delusions (false beliefs) can be seen in delirium

Delusions — false beliefs — may accompany hallucinations. A common and relatively harmless delusion is “I have to go; I’m late for work.” The hospitalized patient might then get dressed and try to leave. Less common and often less benign are paranoid delusions such as “I know that nurse is trying to poison me” or “My family is trying to have me committed.” These beliefs can be a real obstacle to proper care, and can be difficult to manage. We will mention in a later section that the rule is never try to argue someone out of a delusion.

Mood changes are seen in delirium, and family members might wonder whether the patient is depressed. Personality changes can become apparent, and this can be a source of embarrassment for family when the patient suddenly starts to make racist or sexist comments to staff, or decides to disrobe in front of visiting neighbors. Aggressive behavior can become so severe that the patient requires some form of restraint for patient and staff safety.

Sleep problems are almost universal in delirium. Some patients stop sleeping, and others sleep all day and all night. Far more common, though, is a reversal of the sleep/wake cycle with poor nighttime sleep with many awakenings, and then – partly because of sleep deprivation – abnormal sleepiness during the day, when patients are expected to interact with medical staff and therapy services.

The issue of consent

One very important thing to note is that elderly patients with delirium often have problems with mental functions such as memory, orientation, and language. For this reason, these patients should not be asked to consent to medical procedures or sign legal documents. This includes consent for new medications. In these cases, a family member, friend, or advocate could be asked to consent on behalf of the patient.

What delirium is like for your loved one

Imagine waking up in the hospital after a fitful nap and not knowing where you are or how you got there. Your back hurts and your mouth is dry. You can’t seem to think clearly, and people you’ve never seen before keep coming in to ask you questions. Some kind of large animal walks in and glares at you, and then crawls under your bed. You want to call for help, but all you can do is squeak. You know you have to get out of there, but your arm is snagged on something. It’s your I.V. line, which you yank out but then you see that you’re bleeding. And then you can’t find your pants. Someone seems to have taken your pants. The bleeding is getting worse. Some woman walks by and looks in at you, and then all hell breaks loose. You try to fight the people off, but you end up back in bed, this time with cloth straps tying you to the bed frame. Your heart is racing, thinking about that animal only a few feet underneath you.

The experience of delirium can be frightening

When you see what the experience of delirium is like, you can understand why these patients can have bad things happen to them. They have a very high rate of falls, they are notorious for pulling out lines and tubes (even ventilator tubes), and they often do not follow medical orders. For example, they may stand up and try to walk on a broken leg. As they are unable to watch their own fluid intake, they can get severely dehydrated. They are known to breathe in (aspirate) food, and are prone to develop pneumonia. And when they’re too sleepy even to move from bed, they can get ulcers on their backside if they’re not repositioned at regular intervals by a caregiver.

Management and treatment

Armed with the information provided here, you should be able to recognize the delirium syndrome in your loved one. That is, you can identify the tip of the iceberg. What you cannot do is determine what is below the waterline — the disease causing it — at least without tests and medical consultation. That critical component of the diagnosis is covered in a later section.

What You Can Do

If your loved one is in the hospital and is showing signs of delirium, there are several things you can do to help.

First, be sure the nurse and other medical staff know that the patient is delirious.
Arrange to spend as much time as possible with your loved one. Some hospitals allow you to stay in the room with the patient overnight.
Tell the patient in a calm voice that you know they are having an unusual experience, that you know what it is, and that it is temporary. It does not mean they’re going crazy, even if they’re seeing things. They will probably not remember what you said, but they will remember that they felt reassured. Repeat this reassurance as often as necessary.
If your loved one is having delusions (false beliefs) that cause them to be agitated or uncooperative, try to distract them by talking about or doing something else. Give them news of the neighborhood or talk about things you’ve done together in the past. Never try to argue with a delusional patient; you will not win.
Reorient the patient at regular intervals. “Today is (day/date/season) and it is (time in the am/pm) and you are at (hospital).”
Open the window blinds during the day and close them at night. Try to maintain quiet in the room at night.
Do not leave your loved one alone with a food tray. Help them by setting up meals and making sure they can eat on their own without inhaling food. If they can’t manage, feed them. Do things slowly, and explain as you go.
Bring photographs and other personal items from home to leave at the bedside. Most patients find these things comforting, and they help with maintaining a sense of self.
As you become familiar with the medical routine, see whether you can help the staff by performing tasks such as refilling the water pitcher, ordering meals, or helping to turn the patient in bed.
At regular intervals, ask your loved one about pain and other symptoms they may be having, and report what they say to the staff.
Try to advocate reasonably for your loved one. Talk to the primary doctor about what is known to be causing the delirium. Find out what the prognosis is so that you can provide reassurance.
Remember that the delirium syndrome is temporary. Although a stay in a rehabilitation center or skilled nursing facility may be required after discharge from the hospital, plans for long-term care in a nursing home should not be made during an episode of delirium.

What the Medical Staff Will Do

The medical staff will be well acquainted with delirium and its treatment, and will institute standard protocols for managing the syndrome as well as the underlying diseases.

The medical staff will:

Take vital signs at regular intervals. This includes blood pressure, pulse, temperature, and oxygen saturation.
Check the patient’s condition at regular intervals.
Institute a falls prevention protocol.
Attempt to bring the patient to the toilet at regular intervals.
Observe quiet hours on the unit, per hospital rules. This is especially important at night.
Reorient the patient at regular intervals.
Use medications as needed to maintain safety if the patient is agitated and/or hallucinating or delusional.
Use restraints (bed ties) only if absolutely necessary to maintain safety.
Focus their efforts on diagnosis and treatment of the cause(s) of delirium, as noted below.

Diagnosis and treatment of the underlying illness

To identify the cause(s) of a delirious episode, lab tests and other studies are needed. These may include the following basic tests:

Complete blood count
Blood chemistries
Drug/medication levels
Examination of urine
Heart tracing (EKG)
Chest X-ray
Covid-19 testing, if indicated

An extended laboratory exam may be required to make a diagnosis. This might include a sedimentation rate or C-reactive protein, blood gas, head CT or MRI, EEG of the brain, cerebrospinal fluid studies, echocardiogram, or other specific tests.

The more thorough the evaluation, the better able the medical team is to treat the delirium successfully. These tests take time, cost money, and require at least some cooperation from the patient. For these reasons, a limited evaluation may be done initially, with further tests done if the patient doesn’t respond to initial treatment.

Lab tests are needed to diagnose the cause(s) of delirium

Chest x-ray is performed in elders with delirium

Prognosis: what will the future hold?

In general, delirium is a temporary condition. When the underlying illness is treated, the patient will return to their usual mental state. This doesn’t happen immediately; it takes time. On average, elderly patients with delirium from a treatable cause like infection will normalize over several weeks. What this means is that patients recovering from delirium should not drive a vehicle, operate machinery, or make legal or financial decisions for some time after discharge from the hospital. These activities can be resumed upon clearance from the primary care physician.

Elderly patients with already compromised brain function, such as those with Alzheimer’s disease, may not recover to their baseline function after an episode of delirium. For these individuals, special planning may be needed to ensure a safe discharge.

Key points

Delirium is a syndrome of altered mental state that often comes on suddenly, with symptoms fluctuating over time.
Symptoms include confusion, disorientation, hallucinations, agitation, delusions, sleep problems, and mood and personality changes.
With few exceptions, the presence of the delirium syndrome means there is an underlying disease or condition that must be treated.
Delirium is usually temporary, and improves with treatment of the underlying cause(s).
Delirium can be a frightening experience for the patient.
There is a great deal that can be done to make the delirium experience less terrible and to protect the patient from adverse events like falls.
The prognosis depends partly on the cause(s) of delirium, and partly on the brain health of the patient before the episode.