Delirium in ICU Ups Risk of Dying in Hospital

A new study has found that one-third of patients admitted to an intensive care unit (ICU) will develop delirium, which lengthens hospital stays and substantially increases the risk of dying in the hospital.

“Every patient who develops delirium will on average remain in the hospital at least one day longer,” said Robert Stevens, M.D., a specialist in critical care and an associate professor at the Johns Hopkins University School of Medicine.

Worse, he added, is “if you’re admitted to the intensive care unit and you develop brain dysfunction, your risk of not surviving your hospital stay is doubled.”

Delirium is a type of brain dysfunction characterized by a sudden onset, fluctuating symptoms, inattention and confusion.

For the new study, Stevens led an interdisciplinary team of researchers who sifted through 10,000 published reports before selecting 42 studies that met their specific criteria. For instance, they eliminated any studies that included patients with head injuries, strokes or other neurological disorders to obtain a more precise estimate of delirium in ICU patients.

That left the researchers with 16,595 patients, of which 5,280 — or 32 percent — had confirmed cases of delirium. The researchers then conducted a meta-analysis, which found that delirium was associated with a twofold increase in the risk of dying in the hospital, even after adjusting for severity of illness.

One of the best known causes of delirium is medications such as sedatives, according to the researchers. For instance, benzodiazepine, which is commonly administered to patients to help them calm down and sleep, may lead to disorientation and confusion.

The goal moving forward should be to reduce or eliminate the use of such potentially harmful medications, particularly among higher risk populations, such as the elderly and individuals with dementia, according to Stevens.

Nighttime interruptions should also be kept to a minimum to ensure that patients get a good night’s rest without sedatives, he said.

Other causes of delirium, however, might be harder to address, he noted.

According to the inflammatory hypothesis, illnesses occurring outside the brain, such as severe pneumonia, can lead to inflammation in the brain. Another theory is that delirium is linked to changes in the flow of blood to the brain, sometimes resulting in strokes that are not recognized, the researchers said.

The new study also found that among patients who develop delirium, the risk of long-term cognitive decline increases by 20 to 30 percent.

“We’re seeing that even though you may have a very severe illness or injury and you’re lucky enough to survive, you’re still not quite out of the woods,” Stevens concluded. “We need to think about the measures we can put into place to decrease these long-term burdens.”

The study was published in the British Medical Journal.

Source: Johns Hopkins Medicine