Delirium in ICU

Advisable Frequent Assessment for Delirium in ICU

January 25, 2011 (San Diego, California) — Increased frequency of assessment for delirium throughout the day increases the rate of its detection among patients in the intensive care unit (ICU), as reported by the researcher at the Society of Critical Care Medicine 40th Critical Care Congress.

"Multiple CAM-ICU [Confusion Assessment Method in the ICU] assessments on a daily basis increased the detection of delirium, both in the number of patients diagnosed and in the overall number of delirious days," Betty Tsuei, MD, from the University of Cincinnati in Ohio, said in an oral presentation.

"In our unit, we actually test people 6 times a day, but this is not usually done," Dr. Tsuei. "If you look at some of the papers that are published on the subject, they talk about doing a morning assessment for delirium; most of them base their incidence solely on what they call 'morning testing.' This may underreport the true prevalence of delirium."

Patients who stayed in the SICU less than 2 days and who had a Glasgow Coma Scale score of 14 or less were excluded from the review. In the study, Dr. Tsuei and her colleagues reviewed 334 admissions (310 patients; 24 had repeated admissions) to their surgical ICU (SICU) during 2009. 

To assess delirium, the CAM-ICU was performed every 4 hours while the patient was awake. During 2009, 11,097 CAM-ICU assessments were performed and were analyzed for this study.

A patient was considered delirious after at least 1 delirious day, defined as a 24-hour period beginning at 7:00 AM, during which there was at least 1 positive CAM-ICU assessment, Dr. Tsuei explained.

Boosting the frequency of delirium assessment resulted in an increased detection of delirium.

When assessed just once in the morning, delirium was detected in 117 patients (34%). In contrast, when assessments were performed every 4 hours, delirium was detected in 138 patients (41.3%).

"With more frequent testing, delirium was detected 55% more often than single morning assessment," Dr. Tsuei noted.

The study found positive results on CAM-ICU testing in 521 of 1533 (34%) daytime intervals (7:00 AM to 7:00 PM) and in 524 of 1474 (36%) nighttime intervals (7:00 PM to 7:00 AM).

"This lack of difference between daytime and nighttime detection of delirium dispels the myth of sundowning or nighttime delirium, which is believed to be common during hospitalization. Really, we could find no evidence of this in our review," Dr. Tsuei said in an interview after her presentation.

She added that patients with less delirium were more likely to return home after hospital discharge and to regain their baseline functional status, but patients with more delirium had longer hospital stays and more developmental problems. "We feel that if we can assess more frequently and document delirium earlier that we may be able to positively affect outcomes in these patients," she said.

"My ultimate goal is to empower the nurses to test more than every 4 hours. It should be something they watch for, just as they monitor a patient's temperature or heart rate," Dr. Tsuei noted. "You don't want to leave the patient sitting there with a high heart rate for 3 hours; it's the same thing for delirium. If we find it we can treat it, and we can also try to decrease the risk."

For widespread CAM-ICU testing to be successful, buy-in from a number of people is necessary, Dr. Tsuei said. "You have to have the buy-in from the physicians to recognize that delirium is an actual entity that has consequences and that can be treated, and you have to have buy-in from the nurses, because otherwise they will say it's just one more thing they have to do and may balk at doing the testing. When we developed our protocol, we involved pharmacists, nursing educators, the nurse manager, and the ICU physicians to plan how we would test, evaluate, and manage these patients, and how we would disseminate this protocol throughout our SICU."

Timothy Girard, MD, from Vanderbilt University School of Medicine in Nashville, Tennessee, said Dr. Tsuei and her colleagues have applied a basic tenet of intensive care medicine — frequent and careful monitoring — to a previously neglected but very common aspect of critical illness — brain dysfunction.

"They found that frequent testing, every 4 hours, detected 55% more days of delirium than once-daily testing, an approach that has been used in many research studies and possibly in clinical practice, although there is not much documentation regarding how often the CAM-ICU or other delirium assessment tools are currently being used," Dr. Girard, who moderated the session, said.

"This is likely to be of great value to ICU practitioners, since recent studies have shown that the number of days a patient is delirious is an important independent predictor of adverse long-term outcomes, including death and long-term cognitive impairment," he said.

"In light of these data, ICU clinicians who assess patients frequently for delirium will gain important prognostic information. Also, as this study suggests, frequent monitoring should lead to earlier diagnosis of delirium, which in turn should prompt changes in management, including withdrawal of deliriogenic drugs such as benzodiazepines, treatment of identifiable delirium risk factors, and possibly treatment with antipsychotics."