A two-minute assessment tool can help hospital staff predict a patients risk of delirium, which occurs in as many as one in five hospitalized patients, tends to develop rapidly and can lead to higher death rates and increased healthcare costs.
Researchers with the University of California, San Francisco, said they designed the tool to be simple, efficient and accurate in helping to assess and treat patients at risk of developing delirium. The tool also can be used to identify patients who might be most suitable for targeted interventions to prevent delirium, the authors reported.
Its estimated that up to one third of hospital-acquired delirium cases could be prevented with appropriate interventions, but those interventions are resource-intense and cant be applied to everyone, Vanja C. Douglas, MD, the studys lead author and an assistant professor in the UCSF Department of Neurology , said in a news release.
Our objective was to develop a tool to predict delirium using elements that could be assessed quickly in the fast-paced environment of a hospital. The new tool can be completed by a nurse in two minutes, and provides a clinically useful and practical alternative to existing delirium prediction models.
The precise sequence of events that take place in the body and brain which results in delirium is not well understood, the researchers noted. It is believed that the combination of an aging brain and acute illness creates an imbalance of neurotransmitters that leads to the confusion and disorientation of delirium. Adding powerful medications such as narcotics to the mix can compound the problem.
Established risk factors for delirium include older age, preexisting cognitive dysfunction, dehydration, severe illness, vision and hearing impairment, electrolyte abnormalities and overmedication.
In the study, published Aug. 7 on the website of the Journal of Hospital Medicine, 374 patients took part, each older than 50 and not delirious when admitted to the hospital. The patients were predominately white and lived at home. The research was conducted during 2010 and 2011 at UCSF and the San Francisco Veterans Affairs Medical Center.
On admission, the patients underwent a structured interview involving questions related to their baseline cognitive function, residence, type of pain and visual and hearing abilities, among other factors. Each patients nurses rated them on a scale from not ill to near the point of death. All the patients were assessed for changes in cognition for six days or until discharge.
The scientists devised a tool they termed AWOL, a mnemonic standing for age (A); unable to spell world backward (W); not fully oriented to place (O); and moderate to severe illness severity (L).
The researchers found that subjects with higher AWOL scores were more likely to become disoriented and develop delirium. They also found that conversely, those with low scores were at relatively low risk of developing delirium, meaning that the tool could stratify patients into high- and low-risk groups.
Once identified, patients at greater risk of delirium should be triaged to an inpatient unit specializing in delirium prevention, the researchers said.
The authors noted some study limitations: non-English speaking patients were excluded for logistical reasons, as were patients with profound aphasia or those in alcohol withdrawal when admitted.
The authors also pointed out that prior research on delirium has focused on patients over age 70 since old age is a known risk factor. But for their study, the authors included patients ages 50 and older because hospital-acquired delirium still occurs in this age group. Indeed, 8% of study patients ages 50 to 69 became delirious.
Study abstract: http://onlinelibrary.wiley.com/doi/10.1002/jhm.2062/abstract.