Recognizing, preventing and treating delirium

A large proportion of inpatients have delirium, but in most, it goes unrecognized.


If you remember only one thing about treating agitation and delirium in the hospital, it should be to avoid benzodiazepines, said Bryan Huang, ACP Member, assistant professor of medicine in the division of hospital medicine at the University of California San Diego, during the hospital medicine precourse at Internal Medicine 2011.

Before you get to that point, however, you'll have to recognize your patients with delirium—something hospitalists don't do a great job with, he said.

“Between 15% and 50% of patients have delirium in the hospital, and it's thought to be more common in the postoperative setting. Yet the condition is unrecognized in 70% of cases,” Dr. Huang said.

Delirium increases a patient's length of stay by an average of five extra days, and is associated with loss of independence, increased mortality and worse physical and cognitive recovery, he noted.

Clinical features and risk factors

Clinical features of delirium include disturbances of consciousness, arousal and awareness; attention, perceptual and cognitive disturbances; disorientation; disorganized thinking; delusions; psychomotor disturbances; sleep-wake cycle disturbances; and acute onset, Dr. Huang said.

“A nurse or family member can help inform as to whether what you are observing is baseline behavior, or there has been a shift,” Dr. Huang said.

Patient risk factors for delirium include being older than 65 years, having dementia, having functional dependence or immobility, having multiple comorbidities, taking multiple medications, having visual or hearing impairment, and having chronic renal disease. High-risk situations for delirium include dehydration, infection at hospital admission, electrolyte abnormalities, hypoxia, hypoglycemia, neurologic disorder and untreated pain, he said.

There are risks inherent in the hospital environment, as well. “This is where having an interdisciplinary team comes into play; [its members] can help to minimize some of these risk factors,” Dr. Huang said. Excessive noise, interrupted sleep, unnecessary stimuli, and having a urinary catheter and physical restraints all increase a patient's risk, he said.

Physicians should also pay attention to the medications a patient is on, as some carry a higher risk of delirium, including anticholinergics, antidepressants, opiates, steroids, benzodiazepines, anticonvulsants and insomnia medications, Dr. Huang added.

Assessment

When a patient comes in with potential delirium, the first steps are to rule out other medical causes, review medications, and—in the case of hypoactive delirium—differentiate it from depression, Dr. Huang said.

“The key differences between hypoactive delirium and depression are that, with the former, patients are drowsy and hypoaroused, while they have a normal level of arousal with depression. Hypoactive delirium also has an abrupt onset, while depression is more gradual and chronic,” he noted.

The Confusion Assessment Method (CAM) is the most commonly used instrument in the literature to assess delirium, Dr. Huang noted. It requires that patients have an acute change and fluctuation in mental status compared to their baseline, and difficulty in focusing their attention. In addition, patients must have either disorganized thinking (“a rambling, incoherent, illogical flow of ideas”) or an altered level of consciousness (“anything other than alert”), he said.

Preventing delirium

Hospital staff can take a number of actions to help prevent delirium in those at risk, Dr. Huang noted. These include removing physical restraints and encouraging early mobilization for patients with immobility; providing orienting communication to those with cognitive impairment; using visual aids for those with visual impairments; using hearing aids and adaptive equipment for those with hearing impairment; preventing and correcting dehydration; and providing uninterrupted sleep to those with sleep deprivation.

“For the sleep component, you can avoid checking vitals in the middle of the night, and reschedule procedures so they don't interrupt early morning sleep,” Dr. Huang said.

Patients who were subject to these steps, created as part of the Yale Hospital Elder Life Program (HELP), had a 10% incidence of delirium compared to a 15% incidence in a control group, according to a 1999 study published in the New England Journal of Medicine, Dr. Huang said. In the study of 852 elderly patients, the steps were enacted by an interdisciplinary team that included a geriatric RN specialist, a therapeutic-recreation specialist, a physical therapy consultant, a geriatrician and trained volunteers.

“Even the 15% rate in the nonintervention group was low, so it's possible there was some spillover effect,” Dr. Huang said. “Either way, the study demonstrated that delirium can be prevented in some patients.”

There is some limited evidence supporting pharmacologic prevention of delirium, he added. An October 2005 study in the Journal of the American Geriatric Society of patients undergoing hip surgery found that those who took 1.5 mg of haloperidol per day one to three days preoperatively, and continuing through three days postoperatively, had a shorter delirium duration and length of stay compared to those taking placebo, although incidence of postoperative delirium did not differ between the groups, he noted.

Treating delirium

Not all cases of delirium can be prevented, however. For those in whom it isn't, effective treatments include minimizing the use of catheters, IV lines, restraints and telemetry; correcting dehydration; addressing bowel and bladder issues; ruling out infection; reorienting the patient; monitoring nutrition; providing hearing and visual aids; and mobilizing the patient, Dr. Huang said.

“One of my pet peeves is doctors who order bed rest for patients with delirium. I think in many cases activity with assistance is best indicated,” he said.

To avoid disturbing the sleep-wake cycle, physicians should not place orders for vital signs in the middle of the night, except when medically necessary, and locate the patient's bed closer to a window to provide a better sense of day and night, he suggested.

There is little evidence for the use of antipsychotics in patients with mild, non-agitated delirium. For those with significant delirium/agitation, an April 2007 Cochrane review found haloperidol is best, Dr. Huang said. Caution should be exercised in using this drug with cardiac patients, he added: “You may want to take a baseline EKG to look at the QT interval before prescribing.”