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New Research Looks at Postoperative Delirium

By Bonnie Prescott
Beth Israel Deaconess Medical Center staff


Seventy-six-year-old Ms. R. doesn't remember the events that took place several years ago while she was hospitalized following surgery to remove a polyp from her colon, but her daughter clearly recalls how her normally calm and logical mother seemed to lose all sense of reality, suddenly becoming confused and agitated to the point of not knowing why she was in the hospital in the first place.

"My mother was very confused and would repeat herself many times … mixing up names and times during our conversations," her daughter explains. "It was very scary for the family to see this happen, we didn't know what to do and were confused about what was happening to her … I was feeling hopeless about her future."

Ms. R. was experiencing delirium, an acute state of confusion that primarily affects older individuals, typically developing following illness or infection, during hospitalization, and often after surgery. Patients with delirium may hallucinate and act out, and may be very agitated. In other instances, symptoms of delirium may result in patients being excessively sleepy, unable to pay attention to other people or to respond appropriately to their environment.

"We don't understand the basic mechanisms that lead to the onset of delirium, but we do know that between 15 and 50 percent of older patients undergoing major surgery will experience this state of acute confusion," explains Edward Marcantonio, MD, Director of Aging Research in the Division of General Medicine and Primary Care at Beth Israel Deaconess Medical Center.

In an article in The Journal of the American Medical Association (JAMA), published in early July, Marcantonio described the case of Ms. R., whose experience developing postoperative delirium is typical of older patients. As Marcantonio writes, "At least 2 of 3 cases of delirium develop in the first 2 postoperative days … Later onset delirium is often associated with either a major postoperative complication or withdrawal from alcohol or sedatives."

For Ms. R., the episode proved to be temporary and she was back to normal within several months of returning home. But, as new research is showing, the effects of delirium can linger long after a patient has been discharged from the hospital.

A study co-led by Marcantonio in the July 5 issue of The New England Journal of Medicine (NEJM) found that that of 225 patients between age 60 and 90 who underwent cardiac surgery (either cardiac bypass graft surgery or heart valve surgery), nearly half experienced delirium while they were hospitalized following their surgeries and that follow-up assessments showed that these patients took longer to fully recover normal cognition and continued to experience forgetfulness and confusion for as long as a year after their operations.

"What had been considered a short-term event is now proving to have long-term implications," he adds.

While the exact cause remains a mystery, evidence suggests that anything that disrupts normal brain function can trigger the onset of delirium and the use of anesthesia and postoperative pain medications are being investigated as possible risk factors. But what doctors do know is that certain preexisting conditions put patients at greater risk for developing the condition.

"The more health problems a patient has, the more susceptible they are to experiencing delirium," explains Sharon Inouye, MD, PhD, co-senior author of the NEJM paper and Director of the Aging Brain Center in the Institute of Aging at Hebrew SeniorLife (HSL). "These might include dementia or mild cognitive impairment, significant hearing or vision problems, and dehydration or kidney problems. In addition, patients over 80 and patients who are taking multiple medications also appear to be at greater risk.

"I think that delirium is less a condition unto its own than a collection of stressors that can accumulate and reach a tipping point," adds Inouye.

While delirium can be frightening and disruptive for any person, it can pose a particularly dangerous situation for patients with Alzheimer's disease, according to new research from BIDMC and HSL.

"Among patients with Alzheimer's disease, hospitalization itself can often lead to long-term institutionalization, rapid cognitive decline and death," explains Tamara Fong, MD, PhD, of the Department of Neurology at BIDMC and assistant scientist in the Aging Brain Center in the Institute of Aging at HSL. A study by Fong in the June 2012 issue of the Annals of Internal Medicine found that when Alzheimer's patients also developed delirium during their hospitalizations, these risks became even greater: "The bottom line is that delirium can be a big problem for patients with Alzheimer's disease."

Preparing for Hospitalization

There are, however, effective strategies that doctors and family members can use to help prevent the onset of delirium and treat existing delirium. These include the Hospital Elder Life Program (HELP), a patient care program designed to prevent delirium by keeping hospitalized older people oriented to their surroundings, meeting their needs for nutrition, fluids and sleep and keeping them mobile within the limitations of their physical conditions.

"As growing numbers of older adults are being hospitalized and undergoing elective surgeries, it's critically important that patients and their families be aware of and better understand delirium," adds Marcantonio. "An engaged and attentive family member can help prevent delirium and advocate for the patient."

Drs. Marcantonio and Inouye offer family members the following tips:

  • Consult with a geriatric specialist. When an older person is considering elective surgery or any procedure requiring anesthesia or sedation, advice from a geriatrician can help in making plans for medication, pain control, post-operative mobility and sleep support.
  • Keep things familiar. Take a few family photos or comforting objects (such as a rosary or favorite blanket) to the hospital. Having conversations about events and family members with which the patient is familiar can also be calming.
  • Make sure patients get their eyeglasses, hearing aids and dentures - all items that are sometimes taken away during a hospital stay - in order to stay oriented and able to function.
  • If possible, help patients get up and walk several times a day.
  • Make sure the patient is getting plenty of fluids.
  • Alert medical staff as soon as you see the patient exhibiting any signs of serious confusion.

"Delirium is the most common complication in hospitalized patients over age 65," adds Marcantonio. "When it goes unrecognized, it can hinder a person's recovery."

Above content provided by Beth Israel Deaconess Medical Center. For advice about your medical care, consult your doctor.

Posted July 2012

Contact Information

Division of Gerontology
Department of Medicine
Beth Israel Deaconess Medical Center
Lowry Medical Office Building #1B (West Campus)
110 Francis Street
Boston, MA 02215
617-632-8696

Contact Information

Hebrew Senior Life
1200 Centre Street
Boston, MA 02131
617-363-8000