Public Release: 

Delirium can lead to longer hospitalizations and shorten the life of ICU patients

A major systematic review of published studies indicates a robust association between brain dysfunction in intensive care units and adverse health outcomes

D'Or Institute for Research and Education

This news release is available in Portuguese.

People admitted to a hospital's intensive care unit often suffer from delirium, a clinical syndrome which includes confusion, inattention, hallucinations and sometimes agitation. This condition has been linked to adverse outcomes, but the true magnitude and burden of delirium was not accurately known. Now researchers from the D'Or Institute for Research and Education (IDOR) and the Johns Hopkins University School of Medicine presents the largest systematic review of studies on the subject ever made concluding that delirium is strongly associated with high mortality rates, longer stays in the hospital and post-discharge cognitive impairment.

The group of researchers from Brazil and USA analyzed 42 published studies on ICU delirium and its outcomes, with a total of 16,595 patients. Delirium was identified in 5280 (32%) critically ill patients from these studies. When compared with critically ill patients that did not develop delirium, patients with delirium showed a two-fold increase in the risk of death during hospitalization.

They also found that patients who suffered from this condition stayed in the ICU 1.38 days longer than other patients and needed to be under mechanical ventilation to artificially breathe 1.79 days longer than patients without delirium.

Delirium has been described as one of the most common types of organ dysfunction encountered in the ICU. It is a severe form of brain impairment which can occur in response to various factors, such as inflammation caused by the illness that led to the hospitalization, or the use of certain medicines.

"The concern about ICU delirium is relatively recent; the first landmark ICU studies about it were published in 2001 and since then it is proving to be a very important and challenging matter in healthcare", states Dr Jorge Salluh, the Brazilian physician from IDOR who is one of the authors of the study published in this week issue of BMJ. "Delirium can happen due to multiple causes, even if the patient's disease isn't neurological. If you have pneumonia, for example, and you go to the ICU you might have delirium and also worse outcomes."

The condition is more frequent among the elderly, those with preexisting cognitive impairments and subjects with terminal illnesses. Although it is a common condition, it can be overlooked, misdiagnosed, and underestimated by health care providers working in the ICU. One of the reasons for this is that many patients stay sedated for long periods in the intensive care and then the signs cannot be seen. Moreover, there are cases in which the delirium is "hypoactive" and the patient only shows subtle indications of confusion without being agitated.

The results of the study bring light to the true magnitude of delirium allowing clinicians, researchers and policymakers to allocate resources towards reducing delirium morbidity and mortality. "This is a strong signal that all critically ill patients must be screened and monitored for delirium", points out one of the authors, Dr Robert D. Stevens from the Johns Hopkins University School of Medicine. "Now we hope to see comprehensive efforts to decrease the burden of delirium via prevention and therapeutic interventions."

Delirium can be preventable by a range of interventions such as rational use of sedation and anesthesia, reduced exposure to benzodiazepines, promotion of sleep and early implementation of mobility and occupational therapy in the ICU. "Delirium is a potentially modifiable risk factor for adverse outcomes in hospitalized critically ill patients, we just have to give it the attention that it deserves", concludes Salluh.

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About the IDOR

The D'Or institute of Research is a nonprofit organization which aims to promote scientific and technological progress in healthcare through research and education. IDOR was established in 2010 in Botafogo, Rio de Janeiro, Brazil. Since then, the institute is responsible for designing, planning and overseeing most of the educational and research activities conducted by its sponsor, one of the most important hospital groups in Brazil, the Rede D'Or São Luiz. Our main areas of research are neurosciences, oncology, intern medicine, intensive medicine and pediatrics.

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