Experts weigh in on challenges of anesthetizing the elderly

“People are never more alike than they are at birth, nor more different or unique than when they enter the geriatric era.” Those are the words of noted researcher Stanley Muravchick, MD, professor of anesthesia at the Hospital of the University of Pennsylvania. Those words are included in the Syllabus on Geriatric Anesthesiology, a resource developed and distributed by the Society for the Advancement of Geriatric Anesthesiology (SAGA).

Muravchick’s comment is one you’ll hear experts on geriatric anesthesiology cite often. That’s because, when it comes to anesthetizing older patients for surgical procedures, one size definitely does not fit all.

“Geriatric anesthesia is much more complex and varying than anesthesia for a normal 40 year old. It varies from individual to individual,” explained Terri G. Monk, MD, an anesthesiologist with Duke University Health System. “Stan Muravchick said it well.”

Not the Anesthesia

A simple Internet search will turn up scores of tales about geriatric surgical patients who never regained the mental faculties they possessed before surgery. And many of those Web posters blame general anesthesia on their or their loved one’s mental decline. Yet research isn’t bearing that out.

In fact, Monk presented her most recent research in October at the ANESTHESIOLOGY 2011 annual meeting in Chicago. Funded by the Alzheimer’s Association, her study concluded that commonly used inhaled anesthetics don’t increase the incidence of postoperative delirium in the elderly. The 200 study participants, age 65 or older and undergoing major orthopaedic surgery, were followed for three days during their hospital stay. About 13 percent suffered delirium, regardless of the type of anesthesia. That was somewhat surprising, since some animal studies suggested that inhaled anesthetics may be damaging to the elderly brain.

“What we did find,” Monk stressed, “is that pre-operative, cognitive status of the patient was the most important predictor. In other words, people who were having some declines in cognitive function prior to surgery didn’t test as well as the other patients, and these were the patients who developed deliria.”

About three years ago, Monk’s research team showed that both pre-operative cognitive function and pre-operative depression predict post-operative delirium. She said her group now is developing a cognitive screening battery to administer to elders before surgery. “If we could identify the people ahead of time who function lower on these specific tests or are depressed, we might be able to focus then on these individuals and do some pre-operative intervention to improve their cognitive outcomes,” she said.

Physiologic Reserve

At the University of Florida, previous studies examined so-called post-operative cognitive dysfunction. “The gist of those studies was that, indeed, elderly patients in certain high-risk procedures have a higher risk of post-operative cognitive dysfunction. Those high-risk procedures would include cardiac surgery and some orthopaedic surgeries,” said Kayser Enneking, MD, professor and chair of Florida’s Department of Anesthesiology.

Yet, again, those studies don’t point to anesthesia as the culprit. “It’s well-known that most geriatric patients don’t have the same degree of physiologic reserve as our younger patients. Even if they present with the same set of co-morbidities or problem set, their ability to handle small derangements in their physical environment around them and their physiologic environment is really greatly impaired compared to younger patients.”

Enneking noted that an appropriate drug dose for a younger patient might be way off the mark for an elderly one. “A geriatric patient often needs a third to a half of the amount of drug,” she said. “It’s oftentimes amazing how little medication they need.”
Yet, Enneking stopped short of endorsing the need for a subspecialty of geriatric anesthesia within her profession.  She noted that geriatric patients are “just too prevalent in our OR. Every generalist anesthesiologist should certainly be comfortable in that realm.”

Geriatric Subspecialty?

Monk, however, believes it’s a good idea. “I would like to see more people interested in it. It’s not as flashy as cardiac anesthesia, and cardiac anesthesia does deal with a lot of elderly patients, but, yes, I do think there should be a specialty within anesthesia for geriatrics, because they are very different,” she said.

Monk also noted that specially trained anesthesiologists might help relieve the consultation pressures on geriatricians. “The one thing that has been shown in the literature to help cognitive outcomes in elderly people after surgery is a consultation by a geriatrician,” she said. “If we can get more people in anesthesia trained in geriatrics so that they could be doing the consultation early on in these high-risk patients, then we might be able to improve outcomes without having to refer everybody to a geriatrician – and there’s a huge shortage of geriatricians in the United States.”

Monk is a founding member and former president of SAGA, which was established in 2000.

SAGA’s story

G. Alec Rooke, MD, an anesthesiologist and professor at the University of Washington, is a SAGA founding member as well and helps handle administration for the organization. “The objective was primarily to promote interest in the care of the older patient having surgery,” Rooke explained. “Most of what we have been doing in these past 11 years has been of an educational nature, though certainly there are members of the society who have had research grants on geriatric-anesthesia topics.”

SAGA was an offshoot of a similar-minded committee of the American Society of Anesthesiologists, and the activities of SAGA and the ASA Committee on Geriatric Anesthesia are “often intertwined,” Rooke said.  In addition to the syllabus, SAGA has also released what it calls a Geriatric Curriculum, a bulleted list of issues important to the anesthetic care of older patients. A “frequently asked questions” document is the most recent addition to the SAGA website: http://sagaha.org.

Rooke, whose interest in geriatric anesthesia was sharpened during his 18 years at the Seattle Veterans Hospital, said SAGA’s next step is the development of patient-oriented materials for the website. He added, “I would like us to have a greater international presence. Frankly, I’d just like to see the society grow.” SAGA boasts about 50 active members.