CAM-ICU
The CAM-ICU (Confusion Assessment Method in the Intensive Care Unit) is an assessment tool that assesses four main features of delirium: Acute onset or fluctuating mental status, inattention, altered level of consciousness and disorganized thought. In order for delirium to be present, a patient must have both features 1 and 2 plus either feature 3 or 4. The CAM-ICU Worksheet is a tool used to perform the assessment.
However, before any delirium testing can be performed it is important to assess a patient's overall level of consciousness. This is typically done using standardized and validated sedation/arousal scales such as the RASS or SAS. If a patient is deemed to be highly sedated or unresponsive to an appropriate level of stimulus (RASS of -4 or 5; SAS 1 or 2), the patient is unable to be assessed. It the patient is unresponsive due to heavy sedation, it is important to evaluate whether or not they truly need to be that sedated or if sedation can be decreased in order to allow for the delirium assessment. If the patient is able to display meaningful responsiveness, as in responds to your voice or light touch, the four features of delirium can be assessed using the CAM-ICU assessment tool.
However, before any delirium testing can be performed it is important to assess a patient's overall level of consciousness. This is typically done using standardized and validated sedation/arousal scales such as the RASS or SAS. If a patient is deemed to be highly sedated or unresponsive to an appropriate level of stimulus (RASS of -4 or 5; SAS 1 or 2), the patient is unable to be assessed. It the patient is unresponsive due to heavy sedation, it is important to evaluate whether or not they truly need to be that sedated or if sedation can be decreased in order to allow for the delirium assessment. If the patient is able to display meaningful responsiveness, as in responds to your voice or light touch, the four features of delirium can be assessed using the CAM-ICU assessment tool.
“Copyright © 2002, E. Wesley Ely, MD, MPH and Vanderbilt University, all rights reserved”
Feature 1 - Acute Onset or Fluctuating Course
Since delirium is defined as an acute change in mental status, it is essential that this feature be met in order to say a patient is delirious. When examining a patient, it is important to ask yourself two main questions:
"Is the patient different from his or her baseline mental status?"
OR
"Has the patient had any fluctuation in mental status in the past 24 as evidenced by fluctuation on a sedation scale, GCS, or previous delirium assessment?"
A patient's baseline mental status can be evaluated based on information from family or friends. Before admission, was the patient generally alert or calm? Did they have any dementia before coming in? The same pre-hospital baseline should always be used unless there is definite permanent shift in baseline mental status after admission, such as in the case of a stroke. In this case, fluctuations within 24hrs may be a better indicator for evaluation.
When examining a patients' fluctuating mental status it is important to look at the whole person, how they communicate, their demeanor etc. Does the patient seem confused about where they are? Do they seem oddly frightened? Are they more agitated or more reserved than they were in the past 24hrs? Agitation scores such as RASS or SAS can be tools that are useful in quantifying their mental status to help determine whether or not there has been any change.
If the answer to either one of these questions is correct, the patient is positive for Feature 1.
Since delirium is defined as an acute change in mental status, it is essential that this feature be met in order to say a patient is delirious. When examining a patient, it is important to ask yourself two main questions:
"Is the patient different from his or her baseline mental status?"
OR
"Has the patient had any fluctuation in mental status in the past 24 as evidenced by fluctuation on a sedation scale, GCS, or previous delirium assessment?"
A patient's baseline mental status can be evaluated based on information from family or friends. Before admission, was the patient generally alert or calm? Did they have any dementia before coming in? The same pre-hospital baseline should always be used unless there is definite permanent shift in baseline mental status after admission, such as in the case of a stroke. In this case, fluctuations within 24hrs may be a better indicator for evaluation.
When examining a patients' fluctuating mental status it is important to look at the whole person, how they communicate, their demeanor etc. Does the patient seem confused about where they are? Do they seem oddly frightened? Are they more agitated or more reserved than they were in the past 24hrs? Agitation scores such as RASS or SAS can be tools that are useful in quantifying their mental status to help determine whether or not there has been any change.
If the answer to either one of these questions is correct, the patient is positive for Feature 1.
Feature 2: Inattention
If a patient is alert, it is important to assess for inattention. This is done through either using the standardized Letters or Picture test. The Letters test should be tried first and if unable to perform the test, the picture test can be administered. If the patient makes more than 2 errors in either assessment, they are deemed to be positive for Feature 2.
Notes: Patients requiring glasses or hearing aids should have them on.
Letters:
Say to the patient, "I am going to read you a series of 10 letters. Whenever you hear the the letter "A", indicate by squeezing my hand." Patients who are unable to squeeze your hand can use another form of communication such as blinking or finger tapping.
Read allowed in a normal voice: "S A V E A H A A R T". It is important not to place any particular emphasis on any of the letters.
If a patient fails to squeeze your hand when an "A" is said or if they squeeze your hand on another letter, it is considered an error.
Pictures:
The pictures test allows you to determine if a patient is able to recognize a certain set of standard pictures on cue cards.
Say to the patient, "Mr./Mrs ________, I am going to show you pictures of some common objects. Watch carefully and try to remember each picture because I will ask what pictures you have seen." You show them 5 of the 10 images from standard CAM-ICU cue cards Packet A or Packet B.
Then you say, "Now I'm going to show you some more pictures. Some of these you have already seen and some are new. Let me know whether or not you saw the picture before by nodding your head for "yes" or shaking your head for "no". (Demonstrate head gestures to patient). Show them now all 10 images, including 5 new ones.
If patient indicates "yes" to a picture not previously shown or "no" to a picture that was previously shown, it is considered an error.
If a patient is alert, it is important to assess for inattention. This is done through either using the standardized Letters or Picture test. The Letters test should be tried first and if unable to perform the test, the picture test can be administered. If the patient makes more than 2 errors in either assessment, they are deemed to be positive for Feature 2.
Notes: Patients requiring glasses or hearing aids should have them on.
Letters:
Say to the patient, "I am going to read you a series of 10 letters. Whenever you hear the the letter "A", indicate by squeezing my hand." Patients who are unable to squeeze your hand can use another form of communication such as blinking or finger tapping.
Read allowed in a normal voice: "S A V E A H A A R T". It is important not to place any particular emphasis on any of the letters.
If a patient fails to squeeze your hand when an "A" is said or if they squeeze your hand on another letter, it is considered an error.
Pictures:
The pictures test allows you to determine if a patient is able to recognize a certain set of standard pictures on cue cards.
Say to the patient, "Mr./Mrs ________, I am going to show you pictures of some common objects. Watch carefully and try to remember each picture because I will ask what pictures you have seen." You show them 5 of the 10 images from standard CAM-ICU cue cards Packet A or Packet B.
Then you say, "Now I'm going to show you some more pictures. Some of these you have already seen and some are new. Let me know whether or not you saw the picture before by nodding your head for "yes" or shaking your head for "no". (Demonstrate head gestures to patient). Show them now all 10 images, including 5 new ones.
If patient indicates "yes" to a picture not previously shown or "no" to a picture that was previously shown, it is considered an error.
If a patient is negative for EITHER Feature 1 or 2, delirium is not present and no further testing is required.
Feature 3: Altered Level of Consciousness
A patient's CURRENT level of consciousness is measured using their RASS score (Note: Any other validated sedation scale can be used). If a patient's RASS is anything other than a 0, alert and calm, they are positive for Feature 3.
Remember, a patient with a RASS of -4 or -5 are unable to be evaluated for delirium.
A patient's CURRENT level of consciousness is measured using their RASS score (Note: Any other validated sedation scale can be used). If a patient's RASS is anything other than a 0, alert and calm, they are positive for Feature 3.
Remember, a patient with a RASS of -4 or -5 are unable to be evaluated for delirium.
Feature 4: Disorganized Thinking
Disorganized thinking is assessed by asking the patient four standard questions and a standard set of commands:
Questions:
1. Will a stone float on water?
2. Are there fish in the sea?
3. Does one pound weigh more than two pounds?
4. Can you use a hammer to pound a nail?
(alternate set)
1. Will a leaf float on water?
2. Are there elephants in the sea?
3. Do two pounds weight more than one pound?
4. Can you use a hammer to cut wood?
Command:
"Hold up this many fingers" (Hold up 2 fingers)
"Now do the same thing with the other hand" (Do not demonstrate)
OR "Add one more finger" (If patient can't move both arms.)
If a patient makes more than 1 error in the question and command assessment combined, they are deemed to be positive for Feature 4.
Disorganized thinking is assessed by asking the patient four standard questions and a standard set of commands:
Questions:
1. Will a stone float on water?
2. Are there fish in the sea?
3. Does one pound weigh more than two pounds?
4. Can you use a hammer to pound a nail?
(alternate set)
1. Will a leaf float on water?
2. Are there elephants in the sea?
3. Do two pounds weight more than one pound?
4. Can you use a hammer to cut wood?
Command:
"Hold up this many fingers" (Hold up 2 fingers)
"Now do the same thing with the other hand" (Do not demonstrate)
OR "Add one more finger" (If patient can't move both arms.)
If a patient makes more than 1 error in the question and command assessment combined, they are deemed to be positive for Feature 4.