Patients moved into isolation during a hospital stay are nearly twice as likely to develop delirium, according to a study, which also found that those who began their stay in isolation are not at increased risk.

The researchers said the study is the largest of its kind to examine the link between delirium and measures taken to prevent the spread of hard-to-treat infections such as Methicillin-resistant Staphylococcus aureus. The measures, known as contact precautions, require patients to be isolated in their own room and healthcare personnel to wear masks, gowns and other protective equipment.

Some clinicians have been concerned that contact precautions may be disorienting to patients, making delirium more likely. Although delirium is generally a temporary condition, it can adversely affect patient care. Symptoms include confusion, an inability to pay attention and fluctuations in alertness.

A team of researchers led by Hannah Day, PhD, of the University of Maryland School of Medicine examined two years of data from the university's 662-bed medical center. They found that patients who were placed on contact precautions at some point after admission to the hospital were 1.75 times more likely to develop delirium. However, patients on contact precautions starting at admission were no more likely to develop delirium.

That finding, the researchers said, suggests that the precautions themselves may not cause delirium. "Patients in our study who were placed on contact precautions later in their hospitalization were generally sicker than those who were on contact precautions from the outset," Day said. "So it's possible that the underlying illness rather than the precautions themselves is responsible for the association with delirium.

"Regardless of cause, we hope clinicians will view a move to isolation as a marker for increased risk of delirium and take appropriate precautions."

The researchers said patients on contact precautions should be educated about the reasons for and the goals of the intervention so they might be more comfortable with it. Clinicians should take extra care to monitor medications and try not to interrupt patients' sleep patterns. In addition, isolation rooms should have clocks, calendars and other orienting objects to help avoid sensory deprivation.

The study appears in the January issue of Infection Control and Hospital Epidemiology, the journal of the Society for Healthcare Epidemiology of America. To access the study via subscription or purchase, visit http://bit.ly/u7KIOd.