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760 PART 6: Neurologic Disorders

decade, the development of tools designed especially with the unique validation studies found the CAM-ICU to have excellent sensitivity
characteristics of critically ill ICU patients in mind has allowed the (89%-100%) and specificity (93%-100%) with high inter-rater reliability
clinician to rapidly and reliably detect delirium at the bedside. 8,11,72 (κ = 0.79-0.96), and subsequent studies have found the sensitivity
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Two assessment tools, the Intensive Care Delirium Screening Checklist to range from 47% to 100% and the specificity to range from 88% to
(ICDSC) and the Confusion Assessment Method for the ICU (CAM- 96%. 8,18,28,72,75-78 As with the ICDSC, patients who are comatose cannot be
ICU), have been validated extensively against expert psychiatric raters assessed using the CAM-ICU but should be evaluated again frequently,
using DSM-IV criteria for delirium; these tools were widely tested in the since patients emerging from coma are high risk for delirium. Patients
ICU setting on both mechanically ventilated and nonmechanically venti- who are moderately sedated (ie, have some response to verbal stimuli) or
lated patients. 8,11,72 Several other tools have been developed and assessed more alert may be assessed for delirium using the CAM-ICM. The CAM-
in validation studies with varying results; these studies suggest the ICU assesses for four features of delirium. According to the recently
Nursing Delirium Screening Scale (Nu-DESC) is a promising tool, though revised format, which was streamlined to improve efficiency, feature 1 is
https://kat.cr/user/tahir99/
more validation data are needed before it can be widely recommended. 71 the acute onset of mental status changes or a fluctuation in mental status
The ICDSC is an eight-item screening tool (Table 82-3) that is com- over the last 24 hours, feature 2 is inattention, feature 3 is altered level of
pleted using clinical information collected during either the previous consciousness, and feature 4 is disorganized thinking. A patient is con-
eight or 24 hours (depending on how often the tool is used). For each of sidered delirious if features 1 and 2 and either feature 3 or feature 4 are
11
the eight items on the checklist, patients are given one point for obvious present (Fig. 82-3). The CAM-ICU tool as well as an in-depth training
8,72
manifestations of the item or zero points if there is no manifestation or the manual are available for download at www.icudelirium.org.
item is not assessable. Before the checklist is completed, level of conscious-
ness is assessed, and the checklist is only completed if the patient is not PROGNOSIS FOLLOWING ICU DELIRIUM
comatose or stuporous (ie, their level of consciousness is rated other than
A or B on the ICDSC scale). A score of 4 or more on the ICDSC identifies Numerous studies have now confirmed that ICU delirium is associated
delirium with 64% sensitivity and 99% specificity according to the origi- with multiple poor clinical outcomes, which can be divided into imme-
nal validation study. More recently, studies have found the sensitivity to diate, short-term, and long-term categories.
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range from 43% to 74% and the specificity to range from 75% to 95%. 28,73 Immediate complications associated with delirium include prolonged
The CAM-ICU is a four-feature delirium-screening tool adapted from mechanical ventilation, use of physical restraints, self-extubation, and
the Confusion Assessment Method for use in nonverbal, mechanically catheter removal. 9,79,80 Indeed, in one recent study of 344 medical and sur-
ventilated ICU patients. It has been translated into over 14 languages gical ICU patients, delirium independently predicted time to extubation
8,72
and has been implemented across the world in medical, cardiovascular, in a dose-dependent fashion, with additional days of delirium predicting
surgical, trauma, and burn intensive care units. 8,16,18,28,74-76 The original more time on the ventilator; the number of days a patient was delirious, in
fact, was the most significant predictor of time on mechanical ventilation. 80
Short-term outcomes associated with ICU delirium include prolonged
TABLE 82-3 The Intensive Care Unit Delirium Screening Checklist ICU length of stay, prolonged hospitalizations, institutionalization after
hospital discharge, increased hospital costs, and increased ICU and
Intensive Care Unit Delirium Screening Checklist (ICDSC)
hospital mortality. 32,36,80-82 After controlling for covariates, caring for
Checklist Item Description patients with ICU delirium is associated with a 39% increase in ICU
costs and a 31% increase in total hospital costs. Elderly postopera-
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Altered level of consciousness a
tive patients who develop delirium in the ICU are 7 times more likely
A No response to be discharged to a place other than home. Finally, patients with
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16
B Response to intense and repeated stimulation ICU delirium have a higher ICU mortality and at least double the
in- hospital mortality rate of nondelirious patients. 16,36,77,81,85,86 The risk
C Response to mild or moderate stimulation
of death following delirium does not end at hospital discharge. Indeed,
D Normal wakefulness delirious patients who survive hospitalization remain at a higher
E Exaggerated response to normal stimulation risk for death in the months after discharge. 77,81,85,86 In one study of
Inattentiveness Difficulty following instructions or easily 275 mechanically ventilated medical ICU patients, those who devel-
distracted oped delirium in the ICU were three times more likely to die in the
6 months following hospitalization than those patients who were never
Disorientation To time, place or person delirious. The association between delirium and long-term mortality
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Hallucination-delusion-psychosis Clinical manifestation or suggestive behavior also increases the longer a patient is delirious, such that after adjusting
Psychomotor agitation or retardation Agitation required use of drugs or restraints or for potential confounders, each additional day of delirium predicts a
slowing 10% increase in the hazard of dying in the 6 to 12 months following
hospitalization for critical illness (Fig. 82-4). 80,81,86
Inappropriate speech or mood Related to events or situation or incoherent Although often not observed by ICU clinicians caring for delirious
speech
patients, other long-term outcomes associated with ICU delirium are
Sleep/wake cycle disturbance Sleeping <4 h/d, waking at night, sleeping often as deleterious as the short-term outcomes. Delirious patients are at
all day high risk for long-term cognitive impairment, and the longer delirium
Symptom fluctuation Symptoms of above occurring intermittently persists in the ICU, the more severe these impairments are likely to be. 87-89
In a prospective study of ICU survivors who underwent neuropsycho-
Total score (one point for obvious 0-8 logical testing, nearly 7 in 10 patients demonstrated signs of cognitive
presence of features above)
impairment 1-year following critical illness. After adjusting for covari-
a If level of consciousness A or B no other features are assessed that day. ates, the duration of delirium in the ICU was independently associated
The Intensive care delirium screening checklist. This 8-item checklist should be completed using clinical with cognitive impairment. These long-term cognitive impairments in
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information gathered over the last 8 or 24 hours. First assess level of consciousness. If level of conscious- ICU survivors manifest in numerous ways, including memory problems
ness is C, D, or E proceed with the remaining items. Patients are given 1 point for having an obvious and executive dysfunction, which can cause difficulty with managing
manifestation of the item. A score of 4 or greater is considered a positive delirium screen. money, reading a map, and following detailed instructions, among
Modified with permission from Bergeron N, Dubois MJ, Dumont M, et al. Intensive Care Delirium other effects. 87,89,90 These impairments have profound effects on patient’s
Screening Checklist: evaluation of a new screening tool. Intensive Care Med. May 2001;27(5):859-864. lives. Rothenhausler et al, for example, followed survivors of the acute

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