For patients and their loved ones, delirium can be a frightening experience. A fluctuating mental status is important to identify because it often signals a need for additional treatment. The Confusion Assessment Method (CAM) diagnostic algorithm enables nurses to assess for delirium by identifying the four features of the disorder that distinguish it from other forms of cognitive impairment. It can be completed in five minutes and is easily incorporated into ongoing assessments of hospitalized patients. (This screening tool is included in the series Try This: Best Practices in Nursing Care to Older Adults, from the Hartford Institute for Geriatric Nursing at New York University's College of Nursing.) For a free online video demonstrating the use of this tool, go to http://links.lww.com/A209.
Seventy-three-year-old Albert Fenn is admitted to the orthopedic unit with a left intertrochanteric fracture, which occurred when he tripped over his chihuahua, Wilma, when rushing to answer his doorbell. (This case is a composite, based on my clinical experience.) His niece, Shirley McFarland, was at the door; when her uncle did not answer, she peered through the window and saw him lying on the floor. She dialed 911 and followed the ambulance to the ED.
Never married, Mr. Fenn lives alone and drives, has dinner with family every Sunday, and plays cards with friends every Friday. His medical history includes diabetes, which is treated with metformin (Glucophage) 500 mg twice daily, and no sign of cognitive impairment.
At the time of hospitalization, his blood pressure is 116/80 mmHg, apical pulse is 92 beats per minute with a regular rhythm, respiratory rate is 20 breaths per minute, and oxygen saturation is 95% on room air. He is afebrile. Ms. McFarland says that her uncle is acting normally. Nonetheless, nurses use the Confusion Assessment Method (CAM) diagnostic algorithm to screen for delirium, which reveals that there's no sign of it: he speaks clearly, is socially appropriate, and concisely describes how he came to be hospitalized, as well as details of his past. He is oriented to time and place and reports his age and birth date. He expresses concern for Wilma and has a plan for her care. He asks about his impending surgery. He is attentive and is able to spell the word world backward.
Mr. Fenn reports that on a scale of 0 to 10, his pain level is 7. After confirming that he has no history of drug allergies or adverse drug reactions, the nurse administers hydromorphone (Dilaudid and others) 2 mg iv for pain and methocarbamol (Robaxin) 1,500 mg by mouth for spasm. Mr. Fenn will be assessed with the CAM regularly throughout his hospitalization; his age, injury, pain, medications (the opioid and the antispasmodic), urinary catheterization, immobility, and impending surgery all place him at risk for developing delirium.
WHY USE THE CAM?
The CAM is a standardized instrument developed for clinicians to identify delirium, an acute change in mental status from baseline, quickly and accurately. It can be used in both clinical and research settings and also distinguishes dementia and delirium. (For a comparison of instruments that can be used to screen for delirium in clinical settings, go online to http://links.lww.com/A332.)
Initially developed by Sharon Inouye and colleagues in the late 1980s and early 1990s from the definition of delirium provided in the Diagnostic and Statistical Manual of Mental Disorders, third edition,1 the CAM has been found to agree more closely with the definition of delirium in the fourth edition, text revision.2, 3 A long and a short version of the CAM are available. The short version, the CAM diagnostic algorithm-also known as the short CAM-includes only the four features found to best distinguish delirium from other types of cognitive impairment.4 The long version is a comprehensive tool used to screen for clinical features of delirium and includes additional questions that further define the four features of delirium identified in the short CAM; for example, one of the 10 questions asks whether the patient has shown evidence of increased level of activity, such as picking at bedclothes or tapping her or his fingers. Another asks whether the patient has exhibited any decrease in activity level (by, say, staring into space or not moving for long periods). While the long form may be a more complete assessment and provide additional detail about a patient's behavior, the short form has been proven to be adequate in identifying delirium. Time constraints make the short form more practical for clinical use; it can be completed in five minutes. The clinician assesses for the presence or absence of delirium by assessing for the following four features:
1. mental status altered from baseline (acute onset or fluctuating)
3. disorganized thinking
4. altered level of consciousness
Delirium is identified only if there's evidence of features 1 and 2, and either 3 or 4 (or both). Patients should be assessed with the short CAM on admission and during each shift. In addition, it should be considered a routine part of assessment of all hospitalized adults (delirium is not isolated to older adults). For more information on the incidence and prevalence of delirium, see Delirium: An Overview of the Problem, above.
ADMINISTERING THE SHORT CAM
Assessment with the short CAM is made through both observation and interview. Inouye found that the sensitivity and specificity of the short CAM are improved when clinicians use standardized questions from formal cognitive-testing tools such as the Mini-Mental State Exam or the Orientation-Memory-Concentration Test (OMCT).3 Both tools assess orientation to time and place, short-term memory, and concentration.
If standardized questions are not used, another approach is to engage the patient in conversation for about one minute about the reason for her or his hospitalization and status of symptoms. For example, questions such as "What brought you to the hospital?" or "How are you feeling now?" help the nurse assess orientation to time and place, test concentration, and evaluate the patient's ability to hold a coherent conversation.
Feature 1. The short CAM begins with evaluating whether mental status has changed from baseline and is accomplished through observation (for conditions such as memory impairment, disorientation, or paranoia) and the input of family members or close acquaintances. Other sources of information include reports from emergency medical services, previous hospital records, the patient's primary care provider, home care agency staff, or clinicians in other settings who've had recent contact with the patient. Family input can be sought to determine whether mental status has returned to baseline.
|Figure. No caption available.|
It's very important that the details of the baseline mental status be documented in a specific spot in the patient's record so that it can be used in subsequent CAM screenings. If a patient has no cognitive impairment at the first CAM assessment, it can be assumed that the patient's baseline mental status is normal and unimpaired. But screening becomes more complex when a patient displays any sign of altered mentation at the time of admission. For example, disorientation to time may be an early symptom of dementia that's normal for the patient. But it could also signify delirium. Therefore, the patient's baseline mental status must be confirmed with a reliable source in order to determine whether the current signs and symptoms are alterations from the norm.
Feature 2 is inattention. Obvious signs of inattention are an inability to focus on a task or on conversation because of lethargy or agitation. Inattentive patients may be easily distracted by noises in the immediate environment, or they may have trouble keeping track of what's being said. Other signs of inattention may be more subtle. A patient may be quiet and subdued, rarely initiating conversation. She or he should be asked to spell the word world backward, recite seven digits forward or five digits in reverse, count backward from 20 to one, or recite the days of the week or months of the year backward. A patient with attention deficits will make errors or will be unable to complete these tasks. This feature may help to differentiate signs of dementia and those of delirium. Patients who have dementia and no delirium at baseline can perform simple attentional tests (counting backward from 20 to one), unless the dementia is advanced.
Feature 3, disorganized thinking, can be assessed by asking standard orientation questions. For example, questions from the OMCT include "Do you know what year it is? What season we're in? Do you know today's date? Do you know what month it is? About what time is it now? Where are we?"24 Disorganized thinking makes answering these question difficult, eliciting evasive, rambling, or irrelevant conversation; an illogical flow of ideas; paranoid statements; or evidence of hallucination. (Remember that in patients with dementia, such signs may be a part of baseline status.)
Feature 4, determined by behavioral assessment, is altered level of consciousness. If the patient's level of consciousness is determined to be anything other than alert (vigilant or restless, lethargic, stuporous or comatose) the patient is considered positive for this feature. Restlessness, agitation, and fearfulness are symptoms of hyperactive delirium, while lethargic or stuporous states may reflect hypoactive delirium. In mixed delirium, patients fluctuate among hypoalert, hyperalert, and normal levels of consciousness. Clinicians frequently don't recognize hypoalert states, often because of their subtle presentation.19
Mr. Fenn. Margorie Wyman, a nurse on the unit, is called into Mr. Fenn's room. His niece is worried about his behavior. After introducing herself, Ms. Wyman explains, "Your brain can be affected by illness, and we need to monitor how well your brain is working. I'd like to ask you a few questions." Mr. Fenn says, "What am I doing here? It's time to feed the dog. Where's Wilma?" Ms. Wyman, who admitted him earlier in the day, sees a distinct change in his mental status from the baseline assessment; she notes that he is positive for feature 1. "Mr. Fenn," she asks, "would you like your niece to remain in the room while we talk?" (The patient should always be given the choice to complete the assessment in private.) "She should stay!!" he says. "Am I going crazy?" "You're just fine," Ms. Wyman assures him. "Your niece can stay, but please," she says, turning to the woman, "don't help him answer any questions. We'll get better information if he does this on his own." His niece nods. "Mr. Fenn, can you spell the word world backward for me?" He begins but is soon distracted by the items on his bedside table. Ms. Wyman notes that he is positive for inattention, feature 2 on the short CAM. "Mr. Fenn, do you know today's date?" she asks next. He seems confused by the question, and again, asks for his dog and for a can opener to open her food. He has feature 3, disorganized thinking. Finally, the nurse notes that his anxiety and vigilance are not abating; she notes the presence of "altered level of consciousness."
Challenges that may arise. Some patients may feel threatened by standardized questions that test mental status. In such a case, engage the patient in conversation and listen closely for errors, repetitions, language problems, and lethargy or agitation. Finally, the CAM is not appropriate for comatose patients; patients must be able to respond to the examiner in order to complete the assessment.
SCORING AND INTERPRETING THE RESULTS
A positive result on the short CAM requires evidence of both features 1 and 2 and either 3 or 4 (patients with dementia who do not have delirium will not display features 1, 2, or 4). If delirium is superimposed on dementia, the patient will display features 1 and 2 and either 3 or 4. Results of the short CAM do not reflect the severity of delirium.
Mr. Fenn has delirium, having exhibited each of the four features on the CAM. Ms. Wyman considers causes and discusses the following with the team:
* discontinuing the urinary catheter immediately
* performing urinalysis with reflex culture
* discontinuing methocarbamol and beginning acetaminophen 650 mg orally every six hours while awake for discomfort, perhaps allowing a reduction in hydromorphone dosage
* mobilizing him as soon as possible after surgery
* anticipating postoperative delirium
Ms. Wyman also puts into place measures to maintain Mr. Fenn's safety and function until the delirium is resolved. These include
* reviewing vital signs, bowel and bladder records, sleep patterns, and medications.
* assessing his pain level.
* implementing fall-prevention measures.
* keeping his glasses within his reach.
* activating the bed alarm.
* placing a sign nearby stating, "Stay in bed. Push the red button for help."
* placing the call button in his lap and moving him to a room that's closer to the nurses' station.
* inviting family to spend more time with him, especially during mealtimes.
* instructing aides to offer food and drink hourly.
* arranging activities that stimulate cognition and socialization, such as card games and visits from volunteers.
Reassessment. The CAM should be administered at predetermined intervals in order to identify any fluctuating or subtle signs of delirium. Assessment at every shift can track the patient's mental status over the course of hospitalization. A resolving delirium may indicate a patient's improvement, while a newly occurring delirium can be a sign of a new complication or the worsening of the underlying problem.
If a translator is used, ask that person to translate the patient's responses literally, not by interpretation. Family members may have trouble doing this; therefore, whenever possible, a translator should be used who is not a relative or close friend.
Training. To improve accuracy in the use of the short CAM, nurses should be trained.25, 26 In a study of 25 nurses, Lacko and colleagues found that those trained in the use of the short CAM along with a brief but formal cognitive assessment were able to improve their identification of delirium significantly.25 Tabet and colleagues found that formal presentations, group discussions, and one-on-one teaching with staff helped reduce the prevalence of delirium and improved detection.27
Translations. The CAM has been translated into six languages. It has also been adapted for use in the ICU,13 in the ED,28 and over the telephone.29 (See Versions of the CAM, above.)
COMMUNICATING THE RESULTS
When a nurse identifies delirium using the CAM, other team members must be made aware of it immediately; the cause may be a new complication requiring immediate treatment. Patients who remain delirious from shift to shift must be discussed in rounds so that the cause is treated and the patient's basic needs-nutrition, hydration, comfort, mobility, elimination, and safety-are continually met.
Delirium can be very stressful to families, who need explanations of its causes and projected course. Family members' help can be enlisted in promoting safety, calm, and normalcy until underlying causes are treated and the delirium resolves. They can bring familiar items to the patient, sit with the patient during procedures, reminisce, reassure the patient of her or his safety, and encourage the patient to eat and drink. Some patients with delirium will recognize that their thought processes are faulty, and they should be told that this is temporary.
Mr. Fenn, continued. Testing reveals that he has a urinary tract infection, which is treated with an antibiotic and discontinuation of the urinary catheter. Both the hydromorphone and methocarbamol are discontinued, and he remains comfortable with acetaminophen 650 mg every six hours. Within 24 hours of the new interventions, Mr. Fenn's delirium begins to clear. He undergoes surgery without complication and without recurrence of delirium. His mental status returns to baseline within 24 hours of the surgery. He begins walking on his first postoperative day and is discharged to a subacute rehabilitation facility on his third day. His discharge paperwork notes the episode of delirium, which clinicians believe to have been caused by a combination of hydromorphone, methocarbamol, and a urinary tract infection. After two weeks, he returns home with a prescription for home care services. Within three months of his accident he is living independently again.
What is the evidence that clinicians can rely on the short CAM to identify patients experiencing delirium? The CAM is widely used in a variety of clinical settings, including the ED.32 In general, it has been found to be a valid tool for screening for delirium, with a high degree of sensitivity and specificity, while being easy to administer.
* Reliability. The reliability and validity of the short CAM depend on the training of those administering it. In one study, interrater reliability was 84% to 100%.4
* Validity. Studies done to assess the validity of the CAM vary according to how the tool is administered (with or without formal cognitive testing), the method of scoring, who is administering it, and whether the tester was trained in the use of the tool.19, 26, 33
* Sensitivity. In one study using the short CAM, 86% of patients were correctly identified as having delirium.32
* Specificity. Using the short CAM, 90% to 100% of patients without delirium were correctly identified.4, 32
For further discussion of the studies on the psychometric properties of the CAM and on telephone and ICU versions of the tool, as well as a comparison of delirium-assessment tools, go to http://links.lww.com/A333 and http://links.lww.com/A332.
Delirium: An Overview of the Problem
Incidence, prevalence, and the difficulties of diagnosis.
Delirium is a significant problem that can accompany illness and hospitalization in older adults; in 1994 Inouye and colleagues reviewed studies conducted over several decades and found that delirium occurred in 14% to 56% of older hospitalized medical patients.5 A more recent metaanalysis of delirium in patients with hip fracture found an incidence of 4% to 53%.6 Delirium is often present by the time a patient seeks ED care; indeed, Elie and colleagues found the prevalence of delirium in elderly ED patients to be 9.6%.7
Delirium can occur at any time during hospitalization, often in response to a worsening illness or new insults, including urinary catheterization, use of physical restraints, malnutrition, any iatrogenic event, or administration of more than three new medications.8 Many factors usually contribute to its development, although patients with advanced age, severe illness, or dementia may develop delirium in response to a single factor.8-10 Delirium is often reversible once its causes are identified and treated.
Delirium is found on general or specialty medical and surgical units, with the highest incidence seen in postoperative patients undergoing cardiac or orthopedic surgery,6, 11 in the ICU,12, 13 and during the last weeks of terminal illness.14 Delirium during hospitalization is associated with increased rates of illness and death, nursing home placement, and readmission, as well as prolonged and costly hospitalizations.5 In fact, delirium may act as a prognostic indicator for death for up to 12 months after hospitalization.15 And it can cause significant stress in patients, spouses, and caregivers.16
Delirium can be difficult to identify because of its transient nature and varied presentation-hypoactivity, hyperactivity, or both-especially when it's superimposed on dementia or depression.17, 18 Delays in diagnosis may be caused by clinicians' ignorance of signs and symptoms, the absence of formal assessment protocols, the clinicians not considering delirium to be a significant diagnosis, and the condition's fluctuating nature.17
In a major study involving hospital nurses educated on the features of delirium, Inouye and colleagues found that nurses failed to identify 69% of patients with delirium.19 Compared with trained researchers who used formal cognitive testing, nurses using the short CAM did poor jobs of recognizing and documenting signs of disorientation, poor memory, inattention, disorganized thinking, and altered level of consciousness during routine care. Four independent risk factors were associated with the underrecognition of delirium: the patient had the hypoactive form of delirium, was 80 years of age or older, had impaired vision, or had dementia. The risk of underrecognition increased as the number of risk factors increased. In fact, the hypoactive form of delirium was seven times more likely to be unrecognized by nurses than was either the hyperactive or mixed form.19 In practice, nurses often notice patients' lethargy but don't recognize it as a feature of hypoactive delirium.
Research has shown that early identification and treatment of delirium result in improved outcomes,20-22 including decreased mortality rates and shorter hospital stays.23
For more information on the Confusion Assessment Method and other geriatric assessment tools and best practices, go to http://www.hartfordign.org, the Web site of the John A. Hartford Foundation-funded Hartford Institute for Geriatric Nursing at New York University College of Nursing. The institute focuses on improving the quality of care provided to older adults by promoting excellence in geriatric nursing practice, education, research, and policy. Download the original Try This document on the Confusion Assessment Method by going to http://www.hartfordign.org/publications/trythis/issue13.pdf.
For more information on best practices in the care of older adults go to http://www.ConsultGeriRN.org. The site lists many related resources and offers continuing education opportunities.
Go to http://www.nursingcenter.com/AJNolderadults and click on the How to Try This link to access all articles and videos in this series.
Versions of the CAM
The Confusion Assessment Method for the ICU (CAM-ICU) allows the examiner to assess attention and disorganized thinking in nonverbal (ventilated) patients.13, 30, 31 It assesses the same four features as the short CAM but incorporates nonverbal tasks such as picture recognition and yes-or-no logic questions.
The specific method (SPEC). Feature 1 reads "acute onset and fluctuating course." This is used to increase the certainty of the diagnosis, but some cases may be missed. Inouye suggests using this in a research setting. The diagnosis is "probable or definite delirium."3
The sensitive method (SENS). Feature 1 reads ''acute onset or fluctuating course. This will detect as many cases of delirium as possible, and is probably more practical in the clinical setting when the CAM is being used as a screening tool. The diagnosis is "possible or probable delirium."3
CAM and the telephone. This is the standard CAM used over the phone.29 Observation is not possible. Researchers assessed 41 patients by telephone and followed up with face-to-face assessment. Eight patients were diagnosed with delirium after the phone assessment; this diagnosis was confirmed in six of these patients upon personal interview. None of the 33 patients who tested negative for delirium by phone were found to have delirium upon face-to-face assessment.
Go to http//links.lww.com/A209 to watch a nurse use the Confusion Assessment Method to screen for delirium in a hospitalized patient and discuss how to administer it and interpret results. Then watch the health care team plan preventive strategies. The video also covers screening for delirium when it's superimposed on dementia, a topic that will be discussed in the January issue of AJN.
View this video in its entirety and then apply for CE credit at http://www.nursingcenter.com/AJNolderadults. Click on the How to Try This series link. All videos are free and in a downloadable format (not streaming video) that requires Windows Media Player.
1. American Psychiatric Association. Diagnostic and statistical manual of mental disorders: DSM-III-R. 3rd ed., rev. Washington, DC: The Association; 1987. [Context Link]
2. American Psychiatric Association. Diagnostic and statistical manual of mental disorders: DSM-IV-TR. 4th ed., text revision. Washington, DC: The Association; 2000. [Context Link]
3. Inouye SK. The confusion assessment method (CAM): training manual and coding guide. New Haven, CT: Yale University School of Medicine; 2003 Feb. http://elderlife.med.yale.edu/pdf/The%20Confusion%20Assessment%20Method.pdf. [Context Link]
4. Inouye SK, et al. Clarifying confusion: the confusion assessment method. A new method for detection of delirium. Ann Intern Med 1990;113(12):941-8. [Context Link]
5. Inouye SK. The dilemma of delirium: clinical and research controversies regarding diagnosis and evaluation of delirium in hospitalized elderly medical patients. Am J Med 1994;97(3):278-88. [Context Link]
6. Bruce AJ, et al. The incidence of delirium associated with orthopedic surgery: a meta-analytic review. Int Psychogeriatr 2007;19(2):197-214. [Context Link]
7. Elie M, et al. Prevalence and detection of delirium in elderly emergency department patients. CMAJ 2000;163(8):977-81. [Context Link]
8. Inouye SK, Charpentier PA. Precipitating factors for delirium in hospitalized elderly persons. Predictive model and interrelationship with baseline vulnerability. JAMA 1996;275(11):852-7. [Context Link]
9. Camus V, et al. Etiologic and outcome profiles in hypoactive and hyperactive subtypes of delirium. J Geriatr Psychiatry Neurol 2000;13(1):38-42. [Context Link]
10. Elie M, et al. Delirium risk factors in elderly hospitalized patients. J Gen Intern Med 1998;13(3):204-12. [Context Link]
11. Dyer CB, et al. Postoperative delirium. A review of 80 primary data-collection studies. Arch Intern Med 1995;155(5):461-5. [Context Link]
12. Balas MC, et al. Delirium in older patients in surgical intensive care units. J Nurs Scholarsh 2007;39(2):147-54. [Context Link]
13. Ely EW, et al. Evaluation of delirium in critically ill patients: validation of the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU). Crit Care Med 2001;29(7):1370-9. [Context Link]
14. Casarett DJ, Inouye SK. Diagnosis and management of delirium near the end of life. Ann Intern Med 2001;135(1):32-40. [Context Link]
15. McCusker J, et al. Delirium predicts 12-month mortality. Arch Intern Med 2002;162(4):457-63. [Context Link]
16. Breitbart W, et al. The delirium experience: delirium recall and delirium-related distress in hospitalized patients with cancer, their spouses/caregivers, and their nurses. Psychosomatics 2002;43(3):183-94. [Context Link]
17. Inouye SK. Delirium in older persons. N Engl J Med 2006;354(11):1157-65. [Context Link]
18. Schuurmans MJ, et al. Early recognition of delirium: review of the literature. J Clin Nurs 2001;10(6):721-9. [Context Link]
19. Inouye SK, et al. Nurses' recognition of delirium and its symptoms: comparison of nurse and researcher ratings. Arch Intern Med 2001;161(20):2467-73. [Context Link]
20. Inouye SK, et al. A multicomponent intervention to prevent delirium in hospitalized older patients. N Engl J Med 1999;340(9):669-76. [Context Link]
21. Milisen K, et al. A nurse-led interdisciplinary intervention program for delirium in elderly hip-fracture patients. J Am Geriatr Soc 2001;49(5):523-32. [Context Link]
22. Naughton BJ, et al. A multifactorial intervention to reduce prevalence of delirium and shorten hospital length of stay. J Am Geriatr Soc 2005;53(1):18-23. [Context Link]
23. Rockwood K, et al. Increasing the recognition of delirium in elderly patients. J Am Geriatr Soc 1994;42(3):252-6. [Context Link]
24. Katzman R, et al. Validation of a short Orientation-Memory-Concentration Test of cognitive impairment. Am J Psychiatry 1983;140(6):734-9. [Context Link]
25. Lacko L, et al. Changing clinical practice through research: the case of delirium. Clin Nurs Res 1999;8(3):235-50. [Context Link]
26. Lemiengre J, et al. Detection of delirium by bedside nurses using the confusion assessment method. J Am Geriatr Soc 2006;54(4):685-9. [Context Link]
27. Tabet N, et al. An educational intervention can prevent delirium on acute medical wards. Age Ageing 2005;34(2):152-6. [Context Link]
28. Lewis LM, et al. Unrecognized delirium in ED geriatric patients. Am J Emerg Med 1995;13(2):142-5. [Context Link]
29. Marcantonio ER, et al. Diagnosing delirium by telephone. J Gen Intern Med 1998;13(9):621-3. [Context Link]
30. Ely EW, et al. Delirium in mechanically ventilated patients: validity and reliability of the confusion assessment method for the intensive care unit (CAM-ICU). JAMA 2001;286(21):2703-10. [Context Link]
31. McNicoll L, et al. Detection of delirium in the intensive care unit: comparison of confusion assessment method for the intensive care unit with confusion assessment method ratings. J Am Geriatr Soc 2005;53(3):495-500. [Context Link]
32. Monette J, et al. Evaluation of the Confusion Assessment Method (CAM) as a screening tool for delirium in the emergency room. Gen Hosp Psychiatry 2001;23(1):20-5. [Context Link]
33. Laurila JV, et al. Confusion assessment method in the diagnostics of delirium among aged hospital patients: would it serve better in screening than as a diagnostic instrument? Int J Geriatr Psychiatry 2002;17(12):1112-9. [Context Link]