Page 160 - ACCCN's Critical Care Nursing

Psychological Care 137

● advanced age The ICDSC contains eight items based on the Diagnostic
● dementia and Statistical Manual of Mental Disorders (DSM-IV) cri-
● illicit substance use teria for delirium and was validated in a study conducted
● excessive intake of alcohol within ICU. It has been shown to be simple to use and
69
● smoking easily integrated into existing patient documentation. 60,69
● sensory deficits All features of delirium are incorporated such as sleep
● renal insufficiency pattern disturbances and hypo- or hyperactivity. The
69
● previous cerebral damage first step in using the ICDSC is an assessment of con-
● hypertension scious level using a five point scale (A–E). Only patients
● congestive heart failure who are adequately conscious, that is, responsive to mod-
● a history of depression erate physical stimuli (C–E on the scale), are able to be
● genetic propensity. 44,63,64 assessed. The eight items of the ICDSC are rated present
Precipitating risk factors occur during the course of (1) or absent (0). A score of four or higher is considered
critical illness and may be disease-related or iatrogenic. to be indicative of delirium.
Increased severity of illness is a precipitant of delirium The CAM–ICU has also been shown to be valid for diag-
in ICU. Metabolic, fluid and electrolyte disturbances nosing delirium in the ICU population (see Further
have also been implicated, particularly in the presence reading for more information). Acute onset of mental
65
58
of infection (inflammatory response) or hypoxia. Acute status changes or fluctuating course is assessed using neu-
injuries affecting the central nervous system (and espe- rological observations conducted over the previous 24
cially those manifesting in coma) are predictive of hours. Inattention is tested in patients who are unable to
44
developing delirium. Given the hypothesised mecha- communicate verbally by using either a picture recogni-
nism underpinning delirium, medications that affect tion or a random letter test. Disorganised thinking is
acetylcholine transmission such as atropine and fentanyl assessed by listening to the patient’s speech and for
are potential precipitants. The risk associated with opioid, patients who are unable to verbally communicate, a
benzodiazepine and other psychoactive medication use simple instruction is administered such as asking the
is less clear-cut, 63,66 although ‘emergence’ delirium, a patient to hold up some fingers. Any conscious level other
rare complication during recovery from anaesthesia, is than ‘alert’ is considered ‘altered’. Scores are not derived
thought to be strongly related to the administration from the CAM-ICU; delirium is either present or absent. 58
of benzodiazepines. Sudden cessation of benzodiaz-
67
epines and tricyclic antidepressants and multiple medi-
51
cation administration may lead to delirium. Other PREVENTION AND TREATMENT OF DELIRIUM
iatrogenic factors such as pain, excessive noise levels, As previously stated, prevention and management of risk
sleep deprivation and immobility have the most poten- factors is the mainstay of delirium treatment therefore
tial to be modifiable. Prevention and therapeutic patients’ risk factors should be identified and where pos-
68
management of risk factors is the mainstay of treatment sible modified (even in the absence of delirium). Poten-
for delirium. tial preventative measures include:
● adequate pain relief
● reassurance to reduce anxiety
Practice tip ● judicious use of sedative medications
● correction of the physiological effects of critical illness
Interview the patient or their family to identify predisposing (for example hypoxia, hypotension and fluid and
risk factors for delirium. Document your findings and incorpo- electrolyte imbalance)
rate these into the plan of care. ● treatment of the underlying illness.
Research into preventative interventions has not been
conducted in ICU, however trials conducted in acute
ASSESSMENT OF DELIRIUM care with the elderly show that many risk factors are
The higher morbidity and mortality associated with delir- potentially modifiable. In one trial a multifaceted inter-
ium and the relative ease of assessing its occurrence vention which included: reorientation strategies, a non-
makes it imperative to incorporate relevant assessment in pharmacological sleep regimen, frequent mobilisation,
routine care. Delirium is diagnosed when both the fea- provision of hearing devices and glasses and early treat-
tures of acute onset of mental status changes or fluctuat- ment of dehydration, led to a significant reduction in the
70
ing course and inattention are present, together with incidence of delirium. The creation of environmental
either disorganised thinking or altered level of consci- conditions that are conducive to rest and sleep, in par-
ousness. A practical delirium assessment screening ticular noise reduction and adjusting light levels appro-
instrument for the critically ill cannot be reliant on priate for the time of day, may also help.
patient–assessor verbal communication. Both the Inten- In cases where non-pharmacological strategies have not
sive Care Delirium Screening Checklist (ICDSC) (Figure succeeded medications such as haloperidol and atypical
34
69
71
7.2) and the Confusion Assessment Method for the Inten- antipsychotics (e.g. Olanzapine) are recommended.
58
sive Care Unit (CAM-ICU) (Figure 7.3) have been However it should be noted that firm evidence of the
shown to fulfil these requirements. efficacy of these medications is lacking, any medication