In the multivariate analysis, only age, Barthel index, and urinary catheterization were associated with the onset of delirium during hospitalization (Table 2). Intravenous fluid therapy lasted longer for patients who experienced delirium (M = 6 days and SD = 5 days vs. M = 3 days and SD = 5 days; p <; .001). A similar trend was seen for the duration of urinary catheterization, but the difference was not statistically significant (M = 6 and SD = 7 vs. M = 5 and SD = 7; p = .07).
Patients who experienced delirium died during hospitalization more frequently (20.6% vs. 10.8%, p = .006). Their average stay was longer (M = 9 days and SD = 10 days vs. M = 7 days and SD = 8 days; p = .007), and their admission DRG weight was higher (M = 1.88 and SD = 1.23 vs. M = 1.37 and SD = 1.16; p <; .001).
The study shows that 13% of internal medicine patients suffer delirium during their hospitalization.
On the basis of nursing records, the study shows that 13% of internal medicine patients experience delirium during their hospitalization and that age, Barthel Index, and urinary catheterization are independently associated with its onset.
Patients in internal medicine departments are usually aged and frequently experience more than one disease. In Spain, a recent study showed that the mean age of patients admitted to internal medicine nursing units of acute care hospitals has increased by 19.3 years over the last 20 years (Casademont, Francia, & Torres, 2011). In other studies, the mean age was between 70 and 72 years, and the average number of diagnosis per episode was 5.4 (Barba Martín et al., 2009; de San Román y de Terán & Guijarro Merino, 2006). In this study, the mean age of patients was above the one observed in the analysis of the basic minimum collection of data of Spanish Internal Medicine Services and that of American studies (Everett, Uddin, & Rudloff, 2007). Given the progressive aging of the population, delirium may become an epidemic affecting hospitalized or institutionalized patients, with the ensuing increase of mortality and economic expenses and a corresponding deterioration of the quality of life of patients and caregivers.
Some multicomponent interventions have proved effective in preventing the onset of delirium in elderly inpatients (Inouye et al., 1999). However, once delirium had occurred, intervention was less effective. Therefore, the most advisable strategy is to take proactive steps against risk factors associated with it. A significant find in this study was the fact that urinary catheterization is independently associated with the onset of delirium. Bladder catheters were already associated with the appearance of urinary tract infections, and yet, it is still commonly performed, often unnecessarily (Gokula, Hickner, & Smith, 2004). Its association with delirium remains widely unacknowledged, albeit, it was described years ago (Inouye & Charpentier, 1996; Van Rompaey et al., 2009). Few prospective studies assess the association of urinary catheterization with a new onset of delirium (Inouye & Charpentier, 1996). However, strategies seeking to improve patient mobility that included restricted urinary catheterization have been associated with a lower occurrence of delirium (Inouye, Bogardus, Williams, Leo-Summers, & Agostini, 2003; Inouye et al., 1999). In this study, average duration of urinary catheterization was about 1 day longer in patients with delirium (the difference was not statistically significant). Nevertheless, before proceeding to urinary catheterization, it is prudent to assess the risk of delirium and the need for catheterization. Elimination of urinary catheters as soon as possible may help to decrease the onset of delirium, but more studies are needed.
It was found that intravenous use of fluids was more frequent and lasted longer in patients with delirium. It is known that delirium increases with the number of perfusions (Van Rompaey et al., 2009). Intravenous therapy implies mobility restrictions for many patients, especially the older adults, and immobility is associated with the onset of delirium.
Multiple other factors contribute to delirium. In contrast with geriatric patients with hip fracture (Chrispal, Mathews, & Surekha, 2010), we found that inability to carry out basic daily living activities, measured with the Barthel Index, was associated with delirium. This finding is in line with other reports in medical inpatients (McCusker, Cole, Dendukuri, & Belzile, 2004). This finding can be explained because lower scores in Barthel Index are associated with immobility. In the older adults, urinary catheterization is a cause of immobility, and immobility also predisposes to pressure ulcers. In this study, pressure ulcers were more frequent in patients with delirium.
Reliance on mention of “delirium” or “confusion” in nursing notes or administrative data as an indicator of delirium was a limitation of this study. Still, the findings showing occurrences of delirium at 13% of admissions is consistent with other studies that used standardized assessment approaches. In a study based on symptoms recorded by nurses using the Confusion Assessment Method (Inouye et al., 1990), the rate of delirium was 12% (Bourdel-Marchasson et al., 2004), and another study conducted by researchers using clinical interviews noted a 15% rate (Cameron, Thomas, Mulvihill, & Bronheim, 1987). At any rate, it cannot be excluded that, in this study, delirium might have been underrecognized, as some studies conducted on doctors (Gustafson, Brannstrom, Norberg, Bucht, & Winblad, 1991) and nurses (Inouye, Foreman, Mion, Katz, & Cooney, 2001) have shown to be sometimes the case. Considering that the Confusion Assessment Method scale is readily applicable, its use both in emergency rooms, where the first contact of patients in the hospital often takes place, and in internal medicine departments, especially on those patients who might require catheterization for diagnostic or therapeutic reasons, may be warranted.
Barba Martín R., Marco Martínez J., Emilio Losa J., Canora Lebrato J., Plaza Canteli S., Zapatero Gaviria A. (2009). Two years analysis of internal medicine activity in the National Health Care System hospitals. Revista Clinica Española, 209, 459–466.
Bernabeu-Wittel M., Jadad A., Moreno-Gaviño L., Hernández-Quiles C., Toscano F., Cassani M., Ollero-Baturone M. (2010). Peeking through the cracks: An assessment of the prevalence, clinical characteristics and health-related quality of life (HRQoL) of people with polypathology in a hospital setting. Archives of Gerontology and Geriatrics, 51, 185–191.
Bourdel-Marchasson I., Vincent S., Germain C., Salles N., Jenn J., Rasoamanarivo E., Richard-Harston S. (2004). Delirium symptoms and low dietary intake in older inpatients are independent predictors of institutionalization: A 1-year prospective population-based study. Journal of Gerontology Series A: Biological Sciences and Medical Sciences, 59, M350–M354.
Cameron D. J., Thomas R. I., Mulvihill M., Bronheim H. (1987). Delirium: A test of the Diagnostic and Statistical Manual III criteria on medical inpatients. Journal of the American Geriatrics Society, 35, 1007–1010.
Casademont J., Francia E., Torres O. (2011). Age of patients admitted to internal medicine departments in Spain: A twenty years perspective. Medicina Clinica, 138, 289–292.
Chrispal A., Mathews K. P., Surekha V. (2010). The clinical profile and association of delirium in geriatrics patients with fractures in a tertiary care hospital in India. Journal of the Association of Physicians of India, 58, 15–19.
de San Román y de Terán C. M., Guijarro Merino R. (2006). Internal medicine hospital departments of Andalucian Public Health System. A description of the clinical activity in 2002. Revista Clinica Española, 206, 4–11.
Everett G., Uddin N., Rudloff B. (2007). Comparison of hospital costs and length of stay for community internists, hospitalists, and academicians. Journal of General Internal Medicine, 22, 662–667.
Gokula R. R. M., Hickner J. A., Smith M. A. (2004). Inappropriate use of urinary catheters in elderly patients at a Midwestern community teaching hospital. American Journal of Infection Control, 32, 196–199.
Gustafson Y., Brannstrom B., Norberg A., Bucht G., Winblad B. (1991). Underdiagnosis and poor documentation of acute confusional states in elderly hip fracture patients. Journal of the American Geriatrics Society, 39, 760–765.
Inouye S. K., Bogardus S. T., Charpentier P. A., Leo-Summers L., Acampora D., Holford T. R., Cooney L. M. Jr. (1999). A multicomponent intervention to prevent delirium in hospitalized older patients. New England Journal of Medicine, 340, 669–676.
Inouye S. K., Bogardus S. T., Williams C. S., Leo-Summers L., Agostini J. V. (2003). The role of adherence on effectiveness of nonpharmacologic interventions: Evidence from the Delirium Prevention Trial. Archives of Internal Medicine, 163, 958–964.
Inouye S. K., Charpentier P. A. (1996). Precipitating factors for delirium in hospitalized elderly persons: Predictive model and interrelationship with baseline vulnerability. Journal of the American Medical Association, 275, 852–857.
Inouye S. K., Foreman M. D., Mion L. C., Katz K. H., Cooney L. M. Jr. (2001). Nurses’ recognition of delirium and its symptoms: Comparison of nurse and researcher ratings. Archives of Internal Medicine, 161, 2467–2473.
Inouye S. K., Rushing J. T., Foreman M. D., Palmer R. M., Pompei P. (1998). Does delirium contribute to poor hospital outcomes? Journal of General Internal Medicine, 13, 234–242.
Inouye S. K., van Dyck C. H., Alessi C. A., Balkin S., Siegal A. P., Horwitz R. I. (1990). Clarifying confusion: The Confusion Assessment Method. A new method for detection of delirium. Annals of Internal Medicine, 113, 941–948.
Lázaro L., Marcos T., Cirera E., Pujol J. (1995). Delirium in an elderly population admitted at a general hospital. Medicina Clinica (Barcelona), 104, 329–333.
Leslie D. L., Zhang Y., Holford T. R., Bogardus S. T., Leo-Summers L. S., Inouye S. K. (2005). Premature death associated with delirium at 1-year follow-up. Archives of Internal Medicine, 165, 1657–1662.
Mahoney F. I., Barthel D. W. (1965). Functional evaluation: The Barthel Index. Maryland State Medical Journal, 14, 61–65.
McCusker J., Cole M., Abrahamowicz M., Primeau F., Belzile E. (2002). Delirium predicts 12-month mortality. Archives of Internal Medicine, 162, 457–463.
McCusker J., Cole M. G., Dendukuri N., Belzile E. (2003). Does delirium increase hospital stay? Journal of the American Geriatrics Society, 51, 1539–1546.
McCusker J., Cole M. G., Dendukuri N., Belzile E. (2004). The delirium index, a measure of severity of delirium: New findings on reliability, validity and responsiveness. Journal of the American Geriatrics Society, 52, 1744–1749.
Moller J. T., Cluitmans P., Rassmussen L. S., Houx P., Rassmussen H., Canet J., Gravenstein J. S. (1998). Long-term postoperative cognitive dysfunction in the elderly: ISPOCD1 study. The Lancet, 351, 857–861.
Norton D., McLaren R., Exton-Smith A. N. (1979). An investigation of geriatric problems in hospital (3rd ed.). London, UK: Churchill-Livingstone.
Robertsson B. (2002). The instrumentation of delirium. In Lindesay J., Rockwood K., MacDonald A. J. (Eds.), Delirium in old age (pp. 9–25). New York, NY: Oxford University Press.
Siddiqi N., House A. O., Holmes J. D. (2006). Occurrence and outcome of delirium in medical in-patients: A systematic literature review. Age and Aging, 35, 350–364.
Stevens L. E., de Moore G. M., Simpson J. M. (1998). Delirium in hospital: Does it increase length of stay? Australian & New Zealand Journal of Psychiatry, 32, 805–808.
Van Rompaey B., Elseviers M. M., Schuurmans M. J., Shortridge-Baggett L. M., Truijen S., Bossaert L. (2009). Risk factors for delirium in intensive care patients: A prospective cohort study. Critical Care, 13, R77.
Witlox J., Eurelings L. S. M., de Jonghe J. F. M., Kalisvaart K. J., Eikelenboom P., van Gool W. A. (2010). Delirium in elderly patients and the risk of postdischarge mortality, institutionalization, and dementia: A meta-analysis. Journal of the American Medical Association, 304, 443–451.