Delirium develops in about 30 percent of patients hospitalized shortly after a stroke and is linked to poorer outcomes, according to a new meta-analysis published in Stroke: Journal of the American Heart Association.

In the first systematic analysis of the four common outcomes in acute stroke patients with delirium - inpatient and 12-month death rates, length of hospital stay and care arrangements after discharge - Canadian researchers analyzed 10 studies. The research included more than 2,000 patients hospitalized after suffering a stroke due to a vessel blockage or bleeding.

Delirium is an acute state of confusion marked by disorientation, attention deficit, altered and fluctuating mental status, and sometimes hallucinations.

Researchers found:
  • In most studies, 10 percent to 28 percent of patients admitted with acute stroke experienced delirium. However, the incidence of delirium was 48 percent in one of the studies.
  • The risk of death in the hospital or within a year of hospitalization is 4.7 times higher for those with delirium.
  • Stroke patients who develop delirium are three times more likely to be discharged to a long-term care facility and stay in the hospital nine days longer.
Unlike dementia, which is a chronic, progressive mental deterioration, delirium can be triggered by other problems such as infection, substance abuse, metabolic abnormalities, renal or heart failure, or medicines.

Recognizing the underlying problems might help improve patients' prognosis, said Gustavo Saposnik, M.D., M.Sc., senior author of the analysis and director of the Stroke Outcomes Research Center at St. Michael's Hospital, an affiliate of the University of Toronto.

Stroke patients with delirium usually require more extensive medical evaluation and monitoring, which contributes to their longer hospital stays.

Delirium can occur anytime after stroke. When it occurs in the acute phase - within seven to 10 days after a stroke - it might be part of the stroke presentation, but more commonly is related to a complication such as respiratory or urinary infection.

In general, stroke patients who experience delirium are older, have more medical problems and suffer larger strokes - factors that might help explain the poorer outcomes. Results of the present analysis couldn't be adjusted for some factors that may influence outcomes, such as stroke severity or accompanying illnesses due to the type of analysis, Saposnik said. Most of the patients were in stroke units at academic hospitals, so their condition could be more complex and result in poorer outcomes than those in community hospitals.

On the other hand, delirium might be recognized and addressed by a multidisciplinary team in a stroke unit to correct predisposing conditions (e.g. dehydration, hypoxia, infection, immobility, pain, medication overuse, sleep deprivation, etc.), which is superior to care provided in general hospital wards.

Identifying and managing delirium could help healthcare providers keep patients living independently longer and improve their quality of life, the researchers wrote.