After surgery, as the sedation wears off, the elderly patient awakens and just doesn’t seem quite right. In the days ahead, the patient is forgetful, perhaps disoriented.

Researchers have begun studying this phenomenon — now with a fancy name, “perioperative neurocognitive disorders” — and are trying to figure out how to prevent it or, failing that, how to treat it.

One of the leaders in this emerging field is Lee A. Fleisher, Robert Dunning Dripps professor of anesthesia and chair of the department of anesthesiology and critical care at the University of Pennsylvania Health System.

He and Rebecca Trotta, director of nursing research and science and director of the geriatric nursing program at the Hospital of the University of Pennsylvania, spoke to us recently about post-surgery cognitive changes in the elderly.

Describe post-surgery delirium and memory changes. How common is it? Who’s at risk?

Fleisher: There are two different issues. One is post-operative delirium, which is a confusional state within the first seven days or so after surgery. The other is what many people call a brain fog, and it can persist three to four months after a procedure. A classic example is someone may say their memory is not what it used to be.

We begin to see delirium in patients who are ages 65 or 70, and it can affect 30 to 50 percent of patients in this age group who are hospitalized. The severity is really a function of what their baseline state is. So if they come in with some memory decline, what people might call mild memory problems, and they’re frail, they are at the greatest risk. On the other side, a higher education level is protective. People who are more active, physically and mentally, are less at risk.

With delirium, medical professionals are used to the patient being totally confused and hyperactive. The problem is that probably the majority of patients are not hyperactive. They are sitting quietly in bed, ready to go home. But if you ask them who the president is, and other questions about orientation, they would not be able to answer.

What we think happens is when patients come into the hospital, particularly if they have surgery, they develop an inflammatory response because that’s how you heal. In older patients with memory problems, the inflammation can basically leak into the brain. That’s what we think causes these problems.

What does your experience tell you?

Trotta: I see a little bit more of this unfolding in practice. What we look for is a change from baseline. Sometimes, that’s hard for clinicians to recognize immediately because they didn’t know the patient prior to surgery. It’s the family who notices. This is not my dad. This is not my mom. They would never talk like this. They would never act like this.

There are risk factors and there are protective factors. It’s important to assess those early on and put preventative measures in place. Being over age 70 and wearing glasses or hearing aids are common risk factors. The hospital environment can be disorienting. Not being able to see well or hear well makes it worse. It can contribute to the onset of delirium.

Sometimes we put unintentional barriers around a patient. For example, a family member might say, “You should rest, don’t get out of bed.” But we know that early ambulation and sitting up in a chair can help patients maintain their cognitive and functional ability.

What are physicians doing to address this?

Fleisher: The American Society of Anesthesiologists has something called the Perioperative Brain Health Initiative. Our partner is AARP, which knows that older adults are worried about their mental capacity as well as their finances and independence. Those can all be affected. Think about it: During this three- to four-month period, these individuals could be vulnerable to being scammed. They’re not quite as quick. They may be vulnerable to being in car accidents. They could forget to take their medication.

The severity depends on the degree of hospitalization. It’s a combination related to surgery and hospitalization. And, again, it’s most common in those with mild cognitive impairment. We think it’s inflammation in the brain that gets better over time. Most anesthesiologists and surgeons haven’t talked about this except for maybe the last year. That’s part of our initiative: to educate people. It’s too common to ignore.

Also, what we know is that a lot of what we use for anesthesia could cause problems. We don’t have a lot of evidence and we’re still doing a lot of trials, but we’re getting the cocktails right and trying to use more non-narcotic pain medication. We’re using more Tylenol or Motrin, any other drugs besides narcotics, if they control the pain as well. But having severe pain is also bad. It’s the Goldilocks phenomenon.

We’re using more regional anesthesia. The best thing in older adults, if they come here and tell us they have mild cognitive impairment, is that we try to use fewer drugs, and less of them, to achieve the same goal. This is an incredibly high priority for the specialty — figuring out how to reduce the risk.

Describe the HELP program and what its benefits are.

Trotta: The HELP program stands for Hospital Elder Life Program. It focuses on interventions. We use a term, excess disability, which includes cognitive decline, functional decline, nutritional decline — all things that an older person can experience after surgery that can put them at greater risk for not living to their full potential later.

The interventions are very straightforward. Addressing sensory concerns. Having the glasses and hearing aids on hand. Also, just visitation, where you just talk with a person. When patients are able to talk about things such as what they did in their prior work life, their hobbies, it helps reorient them. There is also a focus on nutrition — feeding and hydration. Also, ambulation, range of motion, and help with toileting.

Research demonstrates that volunteers can implement the HELP program intervention instead of physicians or nurses, who are doing so much of the medical care. Here at the Hospital of the University of Pennsylvania, we utilize nursing students in their junior or senior year. By doing do, it gives student nurses more exposure to the care of older adults, and when overseen by a geriatric nurse, they can work with patients who may be too complex to have a volunteer. It’s a low-cost way to deliver an intervention that we know will work.

Many hospitals across the country have versions of HELP programs, and there are numerous studies that show the benefits.

What can individual patients or caregivers do?

Fleisher: One thing older adults have available from Medicare is a cognitive screening. It is my advice that when older patients are scheduled for surgery, it’s probably worth going to their primary doctor or a geriatrician to get some assessment of what their baseline mental status is. One of the quickest and easiest things you can do is ask them to draw a clock that reads 11:10. If they have the cognitive wherewithal, they’ll know where to put the hands. Part of the problem is the resources. In a resource-constrained environment, we’d like to target those at greatest risk.

The other things AARP and the American Heart Association and others talk about is getting fit for surgery. Minimizing alcohol, for instance. And what’s called prehabilitation. We don’t know if this works, but we believe it does: You’re about to undergo surgery? Start walking. We’ve actually thought we should send people to the Y and give them a prescription for exercise. In England, there are trials going on to see if this affects recovery after surgery from a physical standpoint. There is also a strong belief it will aid mental recovery.

Otherwise, it’s important to keep your usual routine. If you’re in the hospital, family members might know what to put on the TV at a certain time. Make sure there are visits. Have the grandchildren phone in. Bring what you think that will orient you.

If a patient is still confused after going home, if they still have this brain fog, caregivers need to make sure there are sufficient supports and safeguards — keeping an eye on finances, driving the patient to appointments and on outings. If the fog persists beyond three months, make sure you see a geriatrician or someone who can evaluate whether you have declined mentally.

Trotta: Patients and families should not assume this is normal. “Oh, they’re old, of course they’re getting confused.” As common as it is, this is not a normal consequence of receiving medical treatment. They should be honest and vocal about what their concerns are.