ICU Delirium Linked to Higher Mortality Risk, Long-term Cognitive Decline
October 12th, 2016
BALTIMORE – Delirium is a fact of life in intensive care units (ICUs), with an estimate one-third of patients suddenly developing inattention and confusion.
A new meta-analysis suggests the condition is more than temporarily alarming for patients and families, however. It also increases hospital stays and the patient’s risk of dying in the hospital, as well as raising the likelihood of long-term cognitive decline by as much as 30%, according to a new study appearing in the British Medical Journal.
The study led by Johns Hopkins University researchers establishes the most definitive link thus far between delirium in the ICU and poor outcomes.
"Every patient who develops delirium will on average remain in the hospital at least one day longer," explained co-author Robert Stevens, MD, a specialist in critical care and an associate professor at Johns Hopkins University. Even worse, Stevens pointed out, "if you're admitted to the intensive care unit and you develop brain dysfunction, your risk of not surviving your hospital stay is doubled."
For the study, researchers focused on 42 studies that were prospective observational cohorts or clinical trials of adults in ICUs. All focused on participants who were assessed with a validated delirium screening or rating system and included an association with at least one of four clinical endpoints -- death during admission, length of stay, duration of mechanical ventilation, and any outcome after hospital discharge. Excluded were studies of patients with neurological disorders, those admitted to intensive care after cardiac surgery or organ/tissue transplantation, and those being treated for alcohol or other substance withdrawal. Of the 16,595 patients, 5,280 (32%) had confirmed cases of delirium.
The meta-analysis of the data suggests that delirium doubles hospital mortality, even after adjusting for severity of illness.
A first step for decreasing delirium, according to Stevens, is to reduce or eliminate the use of medications such as benzodiazepines, which, although administered to patients to help them calm down and sleep, may also cause disorientation and confusion. In addition, he said, nighttime interruptions should be kept to a minimum to ensure that patients get a good night's sleep without sedatives.
The study notes that other causes of delirium may be much more difficult to address. One, the inflammatory hypothesis, suggests that illnesses elsewhere in the body, such as severe pneumonia, can lead secondarily to brain inflammation. Delirium also is suspected of being caused by disrupted flow of blood to the brain, sometimes resulting in unrecognized strokes.