Nursing Care for Delirium
Delirium APA
Delirium
is an acute, fluctuating disturbance of consciousness and cognition (American
Psychiatric Association [APA], 2000). It frequently accompanies acute physical
illness and is found in all care settings.
Estimates of the incidence of
delirium range from 7% to 80% for all hospitalized patients; 46% for older
patients receiving home health care services; and 14% to 39% for residents in
long-term care settings.
More recently, in a community-based sample, delirium
was found to be superimposed on dementia in 13% of the cases.
Historical View About Delirium
Previously,
delirium was thought to be self-limiting and benign. Recent discoveries
indicate that delirium is associated with cognitive and functional impairments
persisting for 12 months or more after the index incident of delirium.
Moreover,
delirium portends poorer outcomes, greater costs of care, and greater chances
for dementia and death. Despite these profound negative consequences for
patients, families, health care providers, and society, delirium remains
understudied. The current state of knowledge of delirium is summarized here.
Delirium as Under-Diagnosed or Misdiagnosed
Delirium
is frequently underrecognized and misdiagnosed (although there is disagreement
as to whether more patients are misclassified as false positive or false
negative) (Inouye, Foreman, Mion , Katz, & Cooney, 2001).
Recognition of
delirium is especially problematic in elderly patients with an underlying
dementia or those with the hypoactive hyperalert variant of delirium.
Explanations for the under recognition and misdiagnosis of delirium include the
fluctuating nature of delirium; the variable presentation of delirium; the
similarity among and frequent cooccurrence of delirium, dementia, and
depression; and the failure of providers to use standardized methods of
detection.
Recognition of Delirium
Improving
the recognition of delirium requires a complex and dynamic solution. Knowledge
of delirium and skill in its detection are necessary starting points for
improving the recognition of delirium.
However, knowledge and skill alone are
insufficient, given the profound impediment to the recognition of delirium
posed by negative mind stereotypes.
These conclusions are supported by the work
of McCarthy (2003), which also highlights the powerful influence of the
practice environment on how providers think about and respond to delirium.
Instrument for Delirium Diagnoses
Several
instruments have been developed to screen for or diagnose delirium.
Such
instruments include: Folstein’s Mini-Mental State Examination (MMSE), Inouye’s
Confusion Assessment Method (CAM), Vermeersch’s Clinical Assessment of
Confusion Form A (CAC-A), Albert’s Delirium Symptom Interview (DSI),
Trzepacz’s Delirium Rating Scale (DRS ), Neelon and Champagne’s NEECHAM
Confusion Scale (NEECHAM), O’Keefe’s Delirium Assessment Scale (DAS), and
Breitbart’s Memorial Delirium Assessment Scale (MDAS).
Each has its advantages
and disadvantages; the selection of which instrument to use depends in part on
the purpose and patient population. The most frequently used instrument in
research and clinical practice is Inouye’s CAM. These instruments are reviewed
in greater detail elsewhere (Foreman & Vermeersch, 2004; Rapp et al.,
2000).
Expert opinion recommends the routine use of brief, standardized bedside
screening measures as timely, effective, and inexpensive methods for assessing
cognitive status and diagnosing delirium. Current standards for surveillance of
delirium are to screen for the presence of delirium on admission to the
hospital and at a minimum daily.
Others recommend brief screening every 8 hours
as an element of the standard nursing assessment. Additionally, when there is
evidence of new inattention, unusual or inappropriate behavior or speech, or
noticeable changes in the way the patient thinks, it is recommended that the
assessment be repeated.
Strategies To Treat Delirium
A
few strategies to prevent and/or treat delirium in hospitalized patients have
been tested with various groups of hospitalized adult patients; most have
resulted in only modest benefits (Cole, 1999). The prevailing principles
guiding prevention and treatment consist of multifactorial interventions that:
(a) identify patients at risk.
(b) target strategies to minimize or eliminate
the occurrence of precipitating factors as primary prevention accomplished
through risk reduction.
(c) identify, correct or eliminate the underlying
cause(s) while providing symptomatic and supportive care.
Multicomponent
interventions targeting several risk factors, rather than targeting a single
risk factor for delirium, and interventions with surgical versus medical
patients have proved more successful in reducing the incidence, severity, or
duration of delirium.
However, interventions have had no effect on the
recurrence of delirium or on outcomes 6 months after discharge from the
hospital.
To better understand why these interventions have not been more
successful, some investigators have conducted post-hoc analyzes to identify
characteristics of patients for whom these interventions have failed.
These
analyzes have indicated that these interventions were less successful with
patients who are at greatest risk for delirium: those who are demented,
functionally impaired, and frailer.
However, it is difficult to determine how
to improve these interventions because these studies have been conceptually
confused: efficacy has been confused with effectiveness; changing provider
behavior has been confused with preventing or treating underlying causal agents
for delirium; and primary prevention has been confused with secondary
prevention.
Moreover, interventions have targeted risk factors rather than the
underlying pathogenetic mechanisms (Le., the metabolic and physiological
deviations that disrupt neurotransmitter synthesis and functioning) ( Trzepacz
, 1999).
Also, these studies have not been designed or powered in such a way as
to determine which of the multi components actually contributed to the positive
outcomes.
Prevention And Treatment of Delirium
To
improve the recognition, prevention, and treatment of delirium, the APA (1999),
British Geriatrics Society (1999), and University of low a Gerontological
Nursing Interventions Research Center (Rapp and the low a Veterans Affairs
Nursing Research Consortium, 1998) have developed practice guidelines.
These
guidelines tend to be comprehensive and are generally based on expert clinical
opinion; few aspects of these guidelines are based on empirical evidence.
Moreover, Young and George (2003) the individuals responsible for compiling the
British guidelines found that the existence of guidelines failed to improve the
process and outcomes of care in delirium, indicating that much work remains to
improve the care of individuals at risk for or experiencing delirium.
the basis of this summary of the state of knowledge of delirium, the need for
further study of delirium in all care settings is clearly documented.
Such
study should focus on all aspects of delirium, including the epidemiology and
natural history of delirium, to improve our understanding of the duration,
severeness, persistence, and recurrence of delirium and to better target and
time interventions.
Greater insight into the underlying pathogenetic
mechanism(s) of delirium would enable more rigorous development and testing of
the efficacy and effectiveness of interventions to prevent and treat delirium.