ATrain Education

 

Continuing Education for Health Professionals

Delirium: First, Rule It Out

Module 4

Screening Tools for Delirium

 

The dream police, they live inside of my head

 

The dream police, they come to me in my bed

 

The dream police, they’re coming to arrest me, oh no!

 

Cheap Trick, “Dream Police” (1979)

 

Lab tests, medication chart reviews, and bedside screening tests all have their place in assessing a patient for delirium. Let’s see how these lead to an accurate delirium diagnosis.

Laboratory Tests

The long list of potential causes we discussed earlier can be narrowed down with routine lab work such as a general chemistry panel, toxicology screen, thyroid hormone levels, and head scans to reveal the underlying cause for a patient’s delirium (Registered Nurses’ Association of Ontario, 2010; Maneeton & Maneeton, 2013). In fact, Maneeton and Maneeton call lab tests “essential” to identify delirium causes. They also suggest pulse oximetry, urinalysis, electrocardiogram (ECG), CSF study, radiologic studies, and an EEG (electroencephalogram) if warranted (Maneeton & Maneeton, 2013).

Chart Review

A review of the patient’s chart can reveal pertinent medication history, medical and mental illnesses, and substance abuse (Maneeton & Maneeton, 2013). Unfortunately, while documentation is critical in recognizing and managing delirium, it is often recorded haphazardly or not at all. Several studies call for improved charting (Voyer et al., 2008; Hope et at., 2014).

Confusion Assessment Method (CAM)

[Training in the use of Confusion Assessment Method (CAM) tool is beyond the scope of this course. The CAM tool below is presented for general review to create a basic awareness of the instrument. Please visit www.hospitalelderlifeprogram.org for more information.]

Bedside assessment and screening tools can be easily and quickly performed by trained nursing staff and other healthcare professionals, making them ideal instruments to help identify and decrease, or eliminate, the potential for delirium. The Confusion Assessment Method (CAM) was created in 1988 by Sharon Inouye as an assessment tool for clinicians without psychiatric training to identify and recognize delirium. Today it is the most widely used delirium detection tool in the world (Inouye & vanDyke, 1990).

A study of eleven delirium detection instruments by Wong and colleagues found the CAM “has the best available supportive data as a bedside delirium instrument” because of “the instrument’s ease of use, test performance, and clinical importance of the heterogeneity in the confidence intervals” (Wong & Holroyd-Leduc, 2010).

 

The Confusion Assessment Method Instrument

1.  [Acute Onset] Is there evidence of an acute change in mental status from the patient’s baseline?

2A.  [Inattention] Did the patient have difficulty focusing attention, for example, being easily distractible, or having difficulty keeping track of what was being said?

2B.  [If present or abnormal] Did this behavior fluctuate during the interview, that is, tend to come and go or increase and decrease in severity?

3.  [Disorganized thinking]Was the patient’s thinking disorganized or incoherent, such as rambling or irrelevant conversation, unclear or illogical flow of ideas, or unpredictable switching from subject to subject?

4.  [Altered level of consciousness] Overall, how would you rate this patient’s level of consciousness? (Alert [normal]; Vigilant [hyperalert, overly sensitive to environmental stimuli, startled very easily], Lethargic [drowsy, easily aroused]; Stupor [difficult to arouse]; Coma; [unarousable]; Uncertain)

5.  [Disorientation]Was the patient disoriented at any time during the interview, such as thinking that he or she was somewhere other than the hospital, using the wrong bed, or misjudging the time of day?

6.  [Memory impairment]Did the patient demonstrate any memory problems during the interview, such as inability to remember events in the hospital or difficulty remembering instructions?

7.  [Perceptual disturbances]Did the patient have any evidence of perceptual disturbances, for example, hallucinations, illusions or misinterpretations (such as thinking something was moving when it was not)?

8A.  [Psychomotor agitation] At any time during the interview did the patient have an unusually increased level of motor activity such as restlessness, picking at bedclothes, tapping fingers or making frequent sudden changes of position?

8B.  [Psychomotor retardation] At any time during the interview did the patient have an unusually decreased level of motor activity such as sluggishness, staring into space, staying in one position for a long time or moving very slowly?

9.  [Altered sleep-wake cycle] Did the patient have evidence of disturbance of the sleep-wake cycle, such as excessive daytime sleepiness with insomnia at night?

 

The Confusion Assessment Method (CAM) Diagnostic Algorithm

Feature 1: Acute Onset or Fluctuating Course This feature is usually obtained from a family member or nurse and is shown by positive responses to the following questions: Is there evidence of an acute change in mental status from the patient’s baseline? Did the (abnormal) behavior fluctuate during the day, that is, tend to come and go, or increase and decrease in severity?

Feature 2: Inattention This feature is shown by a positive response to the following question: Did the patient have difficulty focusing attention, for example, being easily distractible, or having difficulty keeping track of what was being said?

Feature 3: Disorganized thinking This feature is shown by a positive response to the following question: Was the patient’s thinking disorganized or incoherent, such as rambling or irrelevant conversation, unclear or illogical flow of ideas, or unpredictable switching from subject to subject?

Feature 4: Altered Level of consciousness This feature is shown by any answer other than “alert” to the following question: Overall, how would you rate this patient’s level of consciousness? (alert [normal]), vigilant [hyperalert], lethargic [drowsy, easily aroused], stupor [difficult to arouse], or coma [unarousable])

The diagnosis of delirium by CAM requires the presence of features 1 and 2 and either 3 or 4.

Source: Adapted by Waszynski C. (2012); Inouye S. (1990). CAM permission pending.

 

Confusion Assessment Method-ICU (CAM-ICU)

[Training in the use of Confusion Assessment Method for the ICU (CAM-ICU) tool is beyond the scope of this course. The CAM-ICU tool below is presented for general review to create a basic understanding of the instrument. Please visit www.hospitalelderlifeprogram.org for more information.]

The CAM-ICU instrument was adapted for use with ICU patients in 2001 by Wesley Ely, at Vanderbilt University with Dr. Inouye. It differs from the CAM or other tools in that it can be used with patients unable to speak because of ventilation or other issues (Ely et al., 2001a; Tate, 2012).

 

Source: Ely et al., 2001a,b. CAM-ICU permission pending.

Features and Descriptions

absent

present

I. Acute onset or fluctuating course*

 

 

  1. Is there evidence of an acute change in mental status from the baseline?
  2. Or, did the (abnormal) behavior fluctuate during the past 24 hours, that is, tend to come and go or increase and decrease in severity as evidenced by fluctuations on the Richmond Agitation Sedation Scale (RASS) or the Glasgow Coma Scale?

II. Inattention†

 

 

Did the patient have difficulty focusing attention as evidenced by a score of less than 8 correct answers on either the visual or auditory components of the Attention Screening Examination (ASE)?

III. Disorganized thinking

 

 

Is there evidence of disorganized or incoherent thinking as evidenced by incorrect answers to three or more of the 4 questions and inability to follow the commands?

 

Questions

  1. Will a stone float on water?
  2. Are there fish in the sea?
  3. Does 1 pound weigh more than 2 pounds?
  4. Can you use a hammer to pound a nail?

 

Commands

  1. Are you having unclear thinking?
  2. Hold up this many fingers. (Examiner holds 2 fingers in front of the patient.)
  3. Now do the same thing with the other hand (without holding the 2 fingers in front of the patient).

 

(If the patient is already extubated from the ventilator, determine whether the patient’s thinking is disorganized or incoherent, such as rambling or irrelevant conversation, unclear or illogical flow of ideas, or unpredictable switching from subject to subject.)

IV. Altered level of consciousness

 

 

Is the patient’s level of consciousness anything other than alert, such as being vigilant or lethargic or in a stupor or coma?

 

ALERT:

spontaneously fully aware of environment and interacts appropriately

 

VIGILANT:

hyperalert

 

LETHARGIC:

drowsy but easily aroused, unaware of some elements in the environment or not spontaneously interacting with the interviewer; becomes fully aware and appropriately interactive when prodded minimally

 

STUPOR:

difficult to arouse, unaware of some or all elements in the environment or not spontaneously interacting with the interviewer; becomes incompletely aware when prodded strongly; can be aroused only by vigorous and repeated stimuli and as soon as the stimulus ceases, stuporous subject lapses back into unresponsive state

 

COMA:

unarousable, unaware of all elements in the environment with no spontaneous interaction or awareness of the interviewer so that the interview is impossible even with maximal prodding

Overall CAM-ICU Assessment (Features 1 and 2 and either Feature 3 or 4):

Yes _______     No _______

 

*  The scores included in the 10-point RASS range from a high of 4 (combative) to a low of –5 (deeply comatose and unresponsive). Under the RASS system, patients who were spontaneously alert, calm, and not agitated were scored at 0 (neutral zone). Anxious or agitated patients received a range of scores depending on their level of anxiety: 1 for anxious, 2 for agitated (fighting ventilator), 3 for very agitated (pulling on or removing catheters), or 4 for combative (violent and a danger to staff). The scores –1 to –5 were assigned for patients with varying degrees of sedation based on their ability to maintain eye contact: -1 for more than 10 seconds, -2 for less than 10 seconds, and –3 for eye opening but no eye contact. If physical stimulation was required, then the patients were scores as either –4 for eye opening or movement with physical or painful stimulation or –5 for no response to physical or painful stimulation. The RASS has excellent interrater reliability and intraclass correlation coefficients of 0.95 and 0.97, respectively, and has been validated against visual analog scale and geropsychiatric diagnoses in 2 ICU studies.

 

†  In completing the visual ASE, the patients were shown 5 simple pictures (previously published) at 3-second intervals and asked to remember them. They were then immediately shown 10 subsequent pictures and asked to nod “yes” or “no” to indicate whether they had or had not just seen each of the pictures. Since 5 pictures had been shown to them already, for which the correct response was to nod “yes,” and 5 others were new, for which the correct response was to nod “no,” patients scored perfectly if they achieved 10 correct responses. Scoring accounted for either errors of omission (indicating “no” for a previously shown picture) or for errors of commission (indicating “yes” for a picture not previously shown). In completing the auditory ASE, patients were asked to squeeze the rater’s hand whenever they heard the letter A during the recitation of a series of 10 letters. The rater then read 10 letters from the following list in a normal tone at a rate of 1 letter per second: S, A, H, E, V, A, A, R, A, T. A scoring method similar to that of the visual ASE was used for the auditory ASE testing.

 

Confusion Assessment Method (video 8:30)

Source: U.S. Department of Veterans Affairs (2008). https://www.youtube.com/watch?v=M4wsPTtGeIc

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