Delirium is common among ICU patients; here's how to treat them

Cause might be related to medications

Research shows that 60% to 80% of intensive care unit (ICU) patients experience delirium, making this a significant diagnosis in this population.

"In general, most of our ICU populations will have delirium at some point in their stay," says Jeffrey P. Gonzales, PharmD, BCPS, an assistant professor in critical care at the University of Maryland School of Pharmacy in Baltimore, MD.

"It's a multifactorial issue and probably related to whatever brought them into the hospital," Gonzales says. "If you don't use a delirium assessment toolkit, health care providers are very poor at identifying whether or not a patient has delirium."

One study showed that a little more than one-third of nurses and even fewer physicians correctly identified delirium in their patient populations, he adds.

"That's why the Society of Critical Care Medicine's sedation guidelines recommend that providers use a delirium assessment tool," Gonzales says.

The reason so many patients with delirium are missed is because the condition can manifest itself in one of three different ways, including the following:

1. Hyperactive delirium: These are patients who are combative, agitated, and who often can be identified by a clinical exam, Gonzales says.

2. Hypoactive delirium: "This is the patient who is lying in bed with a decreased level of consciousness and awareness," he explains. "It's easier to miss diagnoses of delirium in these patients."

3. Mixed hyper/hypoactive delirium: Some patients alternate between the two, and this actually is the most common form of delirium in the ICU, Gonzales adds.

Most patients who experience delirium in the ICU develop it while in the hospital, he notes.

The key is to quickly identify delirium and then to look for reversible causes, such as environmental and medication side effects, and to begin treatment, he says.

"We have two very good delirium assessment tools we can use," Gonzales says. "One is the Intensive Care Delirium Screening Checklist (ICDSC), and the other is called the Confusion Assessment Method for the ICU (CAM-ICU)."

Both of these tools have been validated for use in the ICU setting. The screening checklist is better at assessing the type of delirium that fluctuates over a 24-hour period since it uses the previous shift's numbers, as well, Gonzales says.

The confusion assessment method is a more objective screening test than the checklist tool, he adds.

"Usually nurses will give the screening test since they're at the bedside more often than a physician or pharmacist," Gonzales says. "Both tools are easy to administer and have a high sensitivity."

Once patients are diagnosed with having delirium, then it's time to figure out what caused the problem, and hospital pharmacists can be very helpful in this investigation.

"We're looking for reversible causes of delirium, such as medications that cause it, such as benzodiazepines, which are used to treat agitation and anxiety," Gonzales says. "Benzodiazepines are used for sedation of ICU patients, but they also can create delirium."

Opioids also can cause delirium.

The key is to eliminate or reduce the use of these medications when delirium is diagnosed, Gonzales says.

Environmental issues also can cause delirium. For example, patients might be sleep deprived.

"So you should make sure the patient has a good sleep-wake cycle and is sleeping through the night and awake for most of the day," Gonzales says. "You can make sure the lights are on during the day and that the patient has a window that allows light to come through."

Other measures that have been shown to decrease delirium are re-orienting patients, early mobilization, removal of restraints and catheters, and using eye glasses and hearing aids when appropriate, he says.

These types of measures have been shown to decrease the risk of delirium in hospitalized patients, although there are no data in the ICU population, he adds.

Another common cause of delirium is infection, such as sepsis.

When delirium cannot be eliminated through medication changes or environmental manipulation, providers can treat it with drug therapy.

"Drug therapy will help treat delirium, and, currently, the most common drug to treat it is haloperidol," Gonzales says. "It's an antipsychotic that's also effective for treatment of delirium, although there's not a lot of evidence for its use in treating ICU delirium."

The field needs more evidence about drug therapy to treat delirium, and hopefully there will be more information available in the literature within the next five years, Gonzales notes.

"It's a hot topic and a hot research interest, and it's an area where we need more studies — both prevention studies as well as treatment studies," Gonzales says.

The key is to pursue environmental and reversible causes of delirium before moving to drug therapy.

"What you don't want to do is what we've done in the past and that is to oversedate these patients when they have delirium," Gonzales says. "Five, 10 years ago we sedated patients to high levels of sedation so they're in a drug-induced coma state, and we're rethinking that whole practice."

Now the standard is to have ICU patients be more awake and to use antidelirium medications like haloperidol, while minimizing the medications that cause delirium, Gonzales says.

Another step hospital pharmacists should take is to assist in educating staff about how to use the delirium assessment tools.

"We've implemented this past summer a delirium assessment tool, and we've done massive amounts of education for nursing staff and physicians through one-on-one inservices to formal inservices," Gonzales says. "We've put up a poster in the ICU and have used numerous educational techniques to drive home the importance of identifying delirium, and the next stage will be educating on how we treat these patients."


  1. Scheckelhoff DJ, Schneider PJ, Pedersen CA. 2009 ASHP National Survey Results: Implications and Trends for Today's Practice. Presentation at the 44th ASHP Midyear Clinical Meeting & Exhibition in Las Vegas, NV; Dec. 9, 2009.