Postoperative Delirium: How to Recognize It and Prevent It

Postoperative delirium is a common complication after surgery for people over 65 years old. Many different factors can increase the risk of postoperative delirium. While temporary, postoperative delirium can have some long-term effects. 

Here, we’ll talk about what postoperative delirium is, why it’s important, and what the risks are. We’ll also go over what you and your healthcare team can do to help prevent it. 

What is postoperative delirium?

Postoperative delirium is a change in mental status, confusion, or a “brain fog” that can happen to older people after surgery. Sometimes, it can happen immediately after surgery. Other times, it can happen days or weeks late, as explained below.

• Postoperative delirium: The confusion occurs immediately after surgery. Postoperative delirium is common: It can happen in 20% to 45% of older patients after surgery. It can be easy to notice because people may seem confused or act in a very unusual way. These symptoms are usually what healthcare professionals use to make a diagnosis.

• Postoperative cognitive dysfunction: Here, the confusion happens later. It is also common, and it can happen in up to 55% of people having major surgery. However, it can be much less obvious, because people may only show very slight changes in their thinking or behavior. Neuropsychological tests are required for diagnosis.

Both are known as “peri-operative disturbances of cognition,” which means a change in how your brain normally functions. 

Postoperative delirium is an important health topic because it can have serious short-term and long-term consequences for patients and healthcare systems. For patients, this may mean longer hospitalization or increased risks of other health problems. For medical systems, this can mean increased yearly costs that can affect healthcare for all patients. In 2021, the Anesthesia Patient Safety Foundation (APSF) named postoperative delirium a top-10 patient safety priority. 

Who is most at risk for postoperative delirium?

There are several well-known risk factors for postoperative delirium. Some risk factors are related to people’s overall health and lifestyle habits. Other risk factors have to do with the type of medical care someone receives. 

Risk factors based on health

• Age (65 years old and over)

• Having existing confusion or dementia

• Depression

• History of stroke

• Hearing or vision difficulties

• Severe illness or infection

• Having a hip fracture

• Physical weakness or difficulty with daily activities

• Alcohol use

• Pain or sedative medication use

• Poor sleep

• Malnutrition or dehydration

Risk factors related to medical care

• Major surgeries, such as hip, heart, lung, or other open chest surgeries, have a higher risk of postoperative delirium

• Pain or anxiety medication use

• Having a bladder catheter during or after surgery

• Intensive care unit (ICU) stay: Up to 80% of patients who need ICU care after surgery can develop delirium.

How can you recognize postoperative delirium in older people after surgery? 

Delirium, as defined and recognized by medical professionals, is a sudden change in how someone thinks and acts. People can experience it differently. Some people may seem: 

• Confused

• Disoriented

• Agitated

• More emotional than usual

Other people may have a change in their sleep habits and be unusually sleepy or unusually hyperactive during different times of the day.

People with postoperative delirium may not recognize family members or trusted members of their healthcare team. In some cases, people with postoperative delirium may refuse necessary medical care or pull out important medical equipment, like intravenous fluids, heart monitors, and bladder catheters. 

What are the common symptoms of postoperative delirium?

Common symptoms are:

• Increased sleepiness or hyperactivity

• Difficulty awakening from anesthesia

• Confusion

• Difficulty focusing, concentrating, or remembering

• Disorganized thinking and speech

• Unusual or quickly changing emotions

• Hallucinations

• Changes in movement

• Decreased appetite

• New bowel or bladder incontinence

Why is postoperative delirium important? 

Postoperative delirium can have many negative effects, including: 

• Longer hospitalization

• Increased need for long-term care in a nursing home

• Worsening of physical function

• Death

Postoperative delirium can also lead to long-term changes in brain function and cognitive decline. Someone with an episode of postoperative delirium may be more likely to develop dementia in the future. People with postoperative cognitive dysfunction have sometimes found it harder to get back to work and occasionally retire earlier than they planned.

How is delirium different from dementia?

Delirium is a sudden and temporary confusion or change in consciousness that often gets better once whatever is causing it improves. For example, some people develop delirium from having an infection. With treatment of the infection, the symptoms of delirium get better. Medications can sometimes cause delirium. In those cases, delirium may get better after stopping or changing the medication.

Dementia is a chronic — or permanent change — in brain function that typically happens slowly over time. There are different types of dementia that have different causes. Some symptoms of delirium may be similar to dementia, but a big difference is that delirium starts suddenly and eventually improves, so people return to their normal levels of thinking and function. With dementia, the changes in thinking and function happen slowly and do not return to normal.

What causes postoperative delirium?

There are well-known risk factors for postoperative delirium. However, there is no single cause. As we mentioned above, there are risk for factors for postoperative delirium, such as:

• Age 

• Illness

• Surgery

• Medication use

The combination of these risk factors that may lead to postoperative delirium may be different for different people. For example, one person may have hip surgery and not have postoperative delirium. Meanwhile, another person who has hip surgery may have postoperative delirium. 

Right now, there is no specific medical test to diagnose or predict postoperative delirium. But researchers have found some differences in the blood of those who’ve had postoperative delirium that may help give some clues in the future.

Is it possible to prevent postoperative delirium?

Postoperative delirium can be prevented in 40% of cases. There are things that surgeons and anesthesiologists can do that can greatly reduce the risk of developing delirium after surgery:

• Determine which patients may be at risk for postoperative delirium before surgery.

• Use neuropsychological tests to assess patients before surgery.

• Counsel those patients and their families on their risk factors and what to expect.

• Improve risk factors that can be improved before surgery, like malnutrition.

• Avoid certain medications during and after surgery that are known to increase the risk of delirium in older people.

• Treat pain with medications that are less likely to worsen confusion.

• Identify delirium quickly if it occurs in the post-anesthesia care unit.

• Return glasses and hearing aids shortly after surgery and encourage early walking.

These things may not prevent postoperative delirium in all cases, but they can make a difference. In some cases, they may have additional benefits. Determining which patients are at risk and counseling them with their families about these risks may help them to understand what is going on if delirium happens. Improving nutrition before surgery can also help with surgical recovery. Using medications that are less likely to worsen confusion may help reduce the risk of nausea or vomiting after surgery.

There are also some things that you can do when preparing for surgery to help reduce the risk of postoperative delirium. These things include:

• Ask to have a pre-surgery cognitive test.

• Ask a family member or friend to stay with you after surgery.

• Review your medications and ask which ones you should avoid before surgery.

• Ask to get your glasses or hearing aids back right away after surgery.

• Ask for a hospital room with a window.

• Pack family photos, a clock, and calendar to keep in your hospital room if you will be staying overnight.

Scientists are constantly searching for new ways to prevent postoperative delirium. A recent study showed that for people without underlying memory problems or depression, using brain games before surgery may decrease the risk of postoperative delirium.

What is the treatment for postoperative delirium?

There are a few ways to treat postoperative delirium: 

• First, medical professionals may check vital signs, bloodwork, and X-rays to see if there is a medical reason, like an infection, electrolyte imbalance, or low blood oxygen that is causing delirium symptoms. 

• They may also review a patient’s medications and make changes if there is a medication that could be the cause, or if a patient’s surgical pain needs more treatment. 

• Once illness, medication, and pain have been ruled out as causes of delirium, the priority should be supportive therapy.

Supportive therapy means making someone more comfortable without medication. For postoperative delirium, this includes: 

• Re-orienting a person to their surroundings and family

• Returning glasses and hearing aids to improve vision and hearing

• Removing noise from the environment

• Encouraging walking as much as possible

• Resuming usual day and nighttime routines to help improve sleep

Besides helping treat delirium, this kind of therapy may also help prevent delirium in some cases. For this reason, all of these things are important parts of good postoperative care for older people.

If supportive therapy does not work, or if someone with delirium is in danger of hurting themselves or others, there are medications that can help. In general, scientific evidence shows that these types of medications do not make a big difference in the prevention or routine treatment of delirium, including postoperative delirium. With the knowledge we have currently, the best approach to postoperative delirium is prevention and supportive therapy. 

If my loved one had postoperative delirium once, does it mean it will happen again?

This doesn’t mean it will definitely happen again, but it may mean you are at higher risk. Some of the risk factors that may have caused the delirium the first time, like your age and underlying medical conditions, are the same. It is important to tell your surgeon and anesthesiologist about any history of delirium before your surgery so that they may be able to help you reduce your risk. 

Why trust our experts?

Written by:

Kelly Elterman, MD

Kelly Elterman, MD, is a board-certified anesthesiologist by the American Board of Anesthesiologyand has been practicing clinically since she finished her residency training in 2013. Along with her training, she has over 10 years experience in anesthesiology.

Edited by:

Sophie Vergnaud, MD

Sophie Vergnaud, MD, is the Senior Medical Director for GoodRx Health. An experienced and dedicated pulmonologist and hospitalist, she spent a decade practicing and teaching clinical medicine at academic hospitals throughout London before transitioning to a career in health education and health technology.

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