Millions of patients in intensive care units each year develop delirium during their hospitalization and often leave the hospital with cognitive deficits similar to those suffering from traumatic brain injury or mild Alzheimer’s disease.
For almost two decades, Vanderbilt University Medical Center researchers have been studying ICU patients on ventilators and modifying their treatment to combat the debilitating effects of delirium, the sudden disruption of consciousness marked predominantly by inattention and sometimes by vivid hallucinations and delusions.
Delirium can occur secondary to sepsis, hypoxemia (low oxygen), metabolic problems such as liver and kidney disease, and perhaps most commonly by drugs (sedatives) given in the ICU.
Wesley (Wes) Ely, MD, MPH, Grant W. Liddle Professor of Medicine, and his colleagues at Vanderbilt and the VA have identified delirium as one of the most critical problems facing ICU patients — linked with increased deaths, prolonged ICU and hospital lengths of stay and significantly higher medical costs.
What no one knew until recently was that many of these patients end up with a long-term dementia that looks a lot like Alzheimer’s disease. They can’t remember things and have a hard time doing their jobs, often retiring early.
There’s now a center behind the researchers’ study of delirium and dementia — the Critical Illness, Brain Dysfunction and Survivorship (CIBS) Center — directed by Ely and Pratik Pandharipande, MD, MSCI, professor of Anesthesiology.
It’s composed of an interprofessional group of physicians, nurses, psychologists, biostatisticians, epidemiologists, pharmacists, physical and occupational therapists and trainees.
The center’s team members work with patients who are, or have been, critically ill and who have suffered from delirium and are at risk for long-term cognitive, functional and neuropsychological impairments.
The center is part of the Center for Health Services Research within the Institute for Medicine and Public Health (IMPH) and is comprised of faculty from the departments of Medicine, Anesthesiology, Surgery, Psychiatry, Biostatistics and Neurology from Vanderbilt University, the Monroe Carell Jr. Children’s Hospital at Vanderbilt, the Nashville Veterans Affairs Hospital and the University of Pittsburgh Medical Center.
“An important goal of our research is helping those in our care, and by extension improving the lives of people we’ll never meet (people around the world who are in critical care units),” Ely said. “In critical illness, to do that, you can’t just focus on one organ or one type of intervention — the lungs and the ventilator, for example. If you do that, you’re not doing your job.”
Ely, a specialist in pulmonary and critical care medicine, said ICU care has historically focused on the patient’s individual organs, such as the lungs and heart. “If your lung had a problem, I would focus on the lung. If your heart had a problem, the cardiologist would focus on your heart. Our camera had a very narrow lens, not a wide angle one.”
“We learned early on that many people who went into the ICU often weren’t getting back to where they were after they were discharged. They couldn’t go to their job and they couldn’t find their car in the parking lot. They couldn’t balance their checkbook, they couldn’t be the matriarch or the patriarch of their family anymore and often their lives were destroyed.”
“We were deeply sedating patients in the ICU, and thought we were doing something good, but we were creating an immobilized, extremely unnatural state where the brain would be chemically paralyzed and restrained and the body would be too,” Pandharipande said.
“Then we started paying attention to the entire body, not just the lungs, heart or kidneys. Now we have an entire community of researchers here and at other institutions focused on improving the care and outcomes of critically ill patients with ICU-acquired brain disease that might contribute negatively to a patient’s ability to return to what is most important to them — their family, work, hobbies. That’s what our center is about.”
“When this team’s studies began years ago, delirium and long-term cognitive impairment were not known to be linked to ventilator management of the ICU patient,” said Robert Dittus, MD, Executive Vice President for Public Health and Health Care, senior associate dean for Population Health Sciences and director of the IMPH.
“But their many investigations have demonstrated that to be the case, and their work in developing new and effective bundles of care has saved thousands of lives and, among survivors, significantly reduced the incidence of long-term cognitive impairment, all while reducing the costs of care. CIBS is the global leader in understanding, preventing and treating these problems. Although much has been accomplished, much is yet to be done,” said Dittus, also the Albert and Bernard Werthan Professor of Medicine.
Previously, Ely and colleagues have developed and validated a clinical measurement tool, the Confusion Assessment Method for the ICU (CAM-ICU), which has been translated into more than 30 languages and is recommended as standard of care by the Society for Critical Care Medicine (SCCM) for all patients on mechanical ventilation. They also helped develop the newly revised “ABCDEF bundle” of protocols and guidelines, which interprofessional care teams can implement in partnership with patients and families to ensure a safe and comfortable ICU environment.
A Vanderbilt study published this year in the Lancet Respiratory Medicine of more than 1,000 intensive care unit patients around the country, nearly three-fourths of whom experienced delirium, showed that many drugs given to sedate patients in the ICU are actually increasing their chances of — and duration of — delirium instead of helping them recover.
The Vanderbilt study, led by senior author Ely and first author Timothy Girard, MD, MSCI (now at the University of Pittsburgh), showed that 71 percent of the participants experienced delirium at some point during the study, 69 percent had multiple causes of delirium, more than half had drug-induced delirium, and only one-third had a single cause.
“The center will look at how we advance the science of what’s going on with these patients after critical illness and how we can take care of them and their families, who are also suffering alongside the patient, holistically in the clinic or through our support groups,” Ely said.
Read more about ICU delirium and of the group of Vanderbilt researchers who study the disorder at the center’s website, www.icudelirium.org.
