As many as 56 percent of all seniors over age 65 who are hospitalized in the United States suffer from delirium. The condition, which affects about 2.5 million annually, usually comes on quickly just after surgery, anesthesia, or a severe illness.
“Delirium is a common complication of surgery, but it’s also preventable,” says Sharon K. Inouye, M.D., a Harvard Medical School (HMS) professor of medicine and director of the Aging Brain Center at the Institute for Aging Research.
Hallmarks of the disorder include declines in short-term memory and recall, breaks in attention span, and disorganized thinking, as well as overall varied levels of alertness, awareness and consciousness.
Often acute at onset, delirium may reverse quickly; however, at its worst, symptoms may deliver serious or even fatal results. Delirium’s exact cause is still unknown, but many experts believe several structural and physiological mechanisms, including multiple neurotransmitter disorders, may collaborate to cause it.
A new $11 million grant from the National Institute on Aging has enabled a team of scientists from Harvard Medical School, the Institute for Aging Research at Hebrew SeniorLife, Beth Israel Deaconess Medical Center (BIDMC), and Brigham and Women’s Hospital (BWH) to study the causes and effects of delirium, with the goal of developing new ways of preventing delirium and its long-term consequences.
The study, called SAGES (Successful AGing after Elective Surgery), will track 500 surgery patients over the age of 70, for the length of 1.5 to 3 years, in order to evaluate their post-surgery mental and functional condition.
Researchers will assess participants after having elective surgery for conditions such as total hip or knee replacement, lower extremity arterial bypass, open abdominal aortic aneurysm repair, and lower extremity amputation. The examinations will occur in the hospital or in the patient’s home.
“SAGES will advance our understanding of the short- and long-term outcomes of delirium and, ultimately, help us improve care for older surgical patients,” said Inouye.
“While most seniors who suffer an episode of delirium go on to a full recovery,” she said, “nearly 20 percent experience complications, including death. Up to 40 percent of delirium episodes, however, are preventable, which makes taking steps to avoid or correctly diagnose this condition crucial.”
Delirium may go unrecognized by physicians and nurses because it is episodic and often manifests simultaneously with dementia. Also, its clinical consequences are largely underappreciated, said Edward Marcantonio, M.D., an HMS associate professor of medicine at BIDMC.
Misdiagnosing delirium, he added, leads to longer hospital stays, missed opportunities for treatment, unnecessary medications, or an overall poorer quality of life.
In an effort to treat delirium, doctors may first look at a patient’s medications, adjusting or stopping any that might contribute to the condition. Disorders that aggravate delirium, including anemia, insufficient oxygen levels in body tissues, infection, and kidney or heart failure, should be treated immediately.
For the SAGES study, medical experts in surgery, psychiatry, neurology, neuropsychology, anesthesiology, medicine, epidemiology, and biostatistics will be brought together to effectively examine the wide range of symptoms related to delerium.
For example, epidemiologists will explore how a person may avoid delirium after surgery or exposure to anesthesia. Other experts will try to predict who is at risk for dementia by looking at molecular changes through inflammatory biomarkers and proteins. MRI testing will also be given both before and after surgery to help determine whether delirium has long-term effects on brain function.
“As the population ages and surgical interventions expand for older people, this study will advance our knowledge about delirium’s long-term effects,” said Selwyn Rogers, M.D., an HMS associate professor of surgery, chief of the Division of Trauma, Burns and Surgical Critical Care at BWH.
“By doing so, we may improve our ability to diagnose delirium in a timely manner and potentially treat it to mitigate its effects.”
Source: Harvard Medical School