The development of delirium in hospitalized elderly patients (ie, hospital-acquired delirium) is common and leads to increased morbidity and mortality in this patient population. In this study, several care gaps for the prevention and timely recognition of delirium (and recognition of predisposing and precipitating risk factors that might have contributed to the prevention of hospital-acquired delirium) were identified. Although delirium is characterized by a fluctuating course and inattention for over the course of 24 hours, only a once-daily cognitive assessment by a nurse was common. As physicians depend partly on health records (ie, nursing notes) to identify a fluctuating course, the recognition of delirium can be delayed by infrequent observation or documentation. Moreover, there was no formal assessment of the hallmarks of delirium: attention and fluctuation; rather, assessment was restricted to a general impression of alertness, orientation, and agitation. Thus, the type of information recorded might also be less than adequate for developing a timely diagnosis of hospital-acquired delirium. This study also identified a lack of delirium-prevention practices, which, if observed, might have reduced the incidence of delirium in this population. These practices included poor documentation of cognitive impairment, special sensory impairment, hydration level, and aspiration risk; excessive urinary catheter use; and a lack of reorientation practices.
Measures to identify possible cognitive impairment were not performed in 16 (12%) patients. Identification of cognitive impairment is important, as it is an important predisposing factor for in-hospital delirium.9
The Mini-Cog is a brief cognitive screening test, which has been shown to be helpful in identifying cognitively impaired patients.5
In this study at the time of admission, there was a history of mild cognitive impairment and dementia in 29 (22%) patients, whereas 45 (34%) patients had abnormal Mini-Cog scores.
Considering the high prevalence of catheter use (27%) and the poor documentation of hydration (57%) in our study population, there remains potential to prevent both UTIs and delirium. Urinary tract infections and nosocomial pneumonias are well-recognized causes of delirium in hospitalized patients1,10,11
; UTIs are particularly problematic for the elderly and are related to the use of catheters, poor hydration, poor hygiene, and poor mobility and toileting. The incidence of bacteriuria in catheterized patients rises from 5% within 24 hours to 50% within 1 week and 100% within 1 month.12
Among patients with bacteriuria, up to 25% will develop symptoms of UTI and about 3% will develop bacteremia.13
Because catheter insertion is convenient and a simple form of continence care, it often leads to indiscreet and prolonged use, placing older adults at risk of UTIs.
Aspiration risk was not identified in 79% of patients, despite the fact that nosocomial pneumonia is the second most frequent cause of hospital-associated infections (after UTIs) and the leading cause of infection-related deaths.11
Delirium is a frequent complication of pneumonia with increased morbidity and mortality.14,15
Delirium might be the only manifestation of pneumonia in elderly patients without other symptoms such as fever.16
Recent studies stress the importance of aspiration as a frequent mechanism, even in community-acquired pneumonia. Silent aspiration of microorganisms from oropharyngeal secretions is also a main cause of pneumonia in the elderly.17
Dehydration and poor oral hygiene are risk factors for aspiration pneumonia in the hospitalized elderly,18
especially in patients who do not have traditional risk factors, such as stroke or nasogastric tube use. Dehydration could lead to inadequate salivary flow, alteration of the normal oral chemical balance, and growth of Gram-negative bacteria, which combined with minimal oral hygiene sets the stage for pneumonia.19
Dehydration can precipitate renal failure, infection, pressure sores, constipation, and delirium. Older adults are at increased risk of dehydration. In a study of hospitalized people aged 70 years and older by Eaton et al, the prevalence of dehydration was 26%.20
In this study, fluid status measurements were done in only 43% of the patients. In this study there was documentation of vision status in 60% of patients and hearing status in 48% of patients. Poor vision and hearing (special sensory impairment) have been shown to be risk factors for delirium.9,21
Delirium is an independent predictor of adverse outcomes, including mortality and institutionalization.22,23
In this study, incident delirium in the hospital was also associated with increased mortality, increased length of stay, and increased institutionalization. Among the 5 subjects who died in the delirious group, terminal delirium related to cancer was seen in 2 patients, hospital-acquired infections, including an aspiration pneumonia and UTI, contributed to delirium in 2 patients, while high doses of narcotics and meperidine use, as well as a UTI and aspiration pneumonia, all contributed to delirium in 1 patient.
This prospective study included patients who were free of delirium at baseline and were followed twice daily using a validated delirium-screening instrument (ie, CAM) until the time of discharge. This is a preliminary study to compare delirium recognition and prevention practices between patients with hospital-acquired delirium and non-delirious patients. This study, to our knowledge, is the first observational study that focuses on basic care gaps identified by chart documentation of health care professionals, which might contribute to delirium prevention and recognition practices in usual medical care. Inadequate basic care practices in older adults can rival the effect of unsafe clinical procedures or interventions and necessitates redesign of health care delivery.
Prevention of delirium would also be likely to decrease length of hospital stay and prevent institutionalization. Efforts should be taken to educate and improve delirium prevention care. We hypothesize that the implementation of a “basic clinical care protocol” for the management of high-risk hospitalized elderly patients will reduce the incidence of delirium and its associated adverse outcomes (eg, injurious falls) in this population.
This study had limitations. It was an observational study based on patient file analysis. As an observational study that is based on patient file analysis, there is a risk of inadequate recording of good practices. Only a prospective randomized trial can adequately determine the effect of the modification of care gaps on the prevention of delirium. In addition the study was performed in one hospital centre, and our findings might not generalize to other settings. Sleep disturbances and immobilization, which are risk factors for delirium, were not evaluated in this study.
Gaps in practices to identify delirium and to prevent its occurrence exist among hospitalized high-risk patients. Remediation of these gaps would be expected to improve the quality of delirium prevention care in the hospital.