Geriatric Emergency Medicine Information Summary: Delirium Fredric M. Hustey, MD What is delirium? Delirium is a syndrome and a medical emergency characterized by: • Acute change in mental status with fluctuating course of severity • Difficulty focusing attention, or attention deficit • Illogical flow of ideas • Altered level of consciousness1 What are the types of delirium? Delirium can be hyperactive (causing hyper vigilance or agitation) or hypoactive (manifesting as CNS depression).1 What causes delirium? • • •
Decreased neurologic reserve + one or more acute insults can = delirium Many things can precipitate delirium. Often the cause is not due to a single agent, but is multi-factorial1 Examples of precipitants: o Infections o Medication side effects or interactions o Electrolyte abnormalities o Endocrine disorders o Inadequate pain management o Malnutrition or dehydration o Restraints o Indwelling catheters (including urinary) o Sensory deprivation o Acute cardiac disease o Ischemic or hemorrhagic stroke
Why is it important to know about delirium in the emergency department?2-11 •
Delirium is a potentially life-threatening medical emergency associated with an increased risk of morbidity and mortality.
Patients with unrecognized delirium who are discharged home from the ED may be 3 times more likely to die within 3 months than counterparts in whom delirium is identified by the emergency physician. Delirium is highly prevalent in older emergency department patients o Approximately 7-10% of all older ED patients suffer from delirium. Delirium is poorly recognized by emergency physicians o Only a small minority (16-38%) of ED patients with delirium are ever recognized as impaired by emergency physicians. Many patients with delirium are discharged home from the ED inappropriately (17-42%) o
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How can you identify delirium in the emergency department?1, 12 There are simple screening tests that can be done to assess for delirium in the Emergency Department. The two most commonly used tests are the Confusion Assessment Method (CAM) and the Confusion Assessment Method for the ICU (CAMICU). These screening tests can be done by any medical professional (physician, nurse, or trained technician). In general the CAM should be used in conjunction with another screening tool (such as the short OMC test or MMSE) to help better assess for CAM features. Do patients with delirium need to be hospitalized?11 Given the increased mortality risk in patients who are discharged home from the emergency department with delirium, strong consideration should be given to hospitalizing these patients unless a single precipitant has been identified that can be adequately treated in the home setting with appropriate social support. How do you manage agitation in the patient with delirium?13 • Sensory deprivation, physical restraints, and indwelling catheters all contribute to the development of delirium. These should be avoided whenever possible • Control pain • Low dose haloperidol (.5-1.0mg IM) is usually the preferred agent for pharmacologic management o avoid in patients with hepatic insufficiency, neuroleptic malignant syndrome, withdrawal syndromes, or QT prolongation • Lorazepam is usually reserved for patients with Parkinson’s disease, alcohol or benzodiazepine withdrawal, or neuroleptic malignant syndrome • Avoid physical restraints whenever possible
The CAM and the CAM-ICU The Confusion Assessment Method Algorithm (CAM) For Delirium1 1.
Is there evidence of an acute change in mental status from the patient’s baseline?
Yes
No
2a. Did the patient have difficulty focusing attention, i.e., being easily distractible or having difficulty keeping track of what was being said? Yes
No
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? Yes
No
3. 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? Yes No 4.
Overall, how would you rate this patient’s level of consciousness? Alert (normal) Vigilant (hyper alert, easily startled) Lethargic (drowsy, easily aroused) Stupor (difficult to arouse) Coma (unarousable)
Delirium Presence of delirium (presence of features 1 and 2 with either 3 or 4) Absence of delirium (not meeting above criteria) REFERENCE: Inouye SK, van Dyck CH, Alessi CA, et al. Clarifying Confusion: The confusion assessment method. Annals of Internal Medicine. 1990;113:941-948.
The Confusion Assessment Method for the Intensive Care Unit (CAM-ICU)14 Features and Descriptions (Absent or Present) I. Acute onset or fluctuating course A. Is there evidence of an acute change in mental status from the baseline? B. 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 3 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
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Inouye SK, van Dyck CH, Alessi CA, Balkin S, Siegal AP, Horwitz RI. Clarifying confusion: the confusion assessment method. A new method for detection of delirium.[see comment]. Annals of Internal Medicine. 1990;113(12):941-948. Elie M, Rousseau F, Cole M, Primeau F, McCusker J, Bellavance F. Prevalence and detection of delirium in elderly emergency department patients. CMAJ Canadian Medical Association Journal. 2000;163(8):977-981. Han JH, Morandi A, Ely W, et al. Delirium in the nursing home patients seen in the emergency department. Journal of the American Geriatrics Society. 2009;57(5):889-894. Han JH, Zimmerman EE, Cutler N, et al. Delirium in older emergency department patients: recognition, risk factors, and psychomotor subtypes. Academic Emergency Medicine. 2009;16(3):193-200. Hustey FM, Meldon SW. The prevalence and documentation of impaired mental status in elderly emergency department patients.[see comment]. Annals of Emergency Medicine. 2002;39(3):248-253. Hustey FM, Meldon SW, Smith MD, Lex CK. The effect of mental status screening on the care of elderly emergency department patients. Annals of Emergency Medicine. 2003;41(5):678-684. Kakuma R, du Fort GG, Arsenault L, et al. Delirium in older emergency department patients discharged home: effect on survival. Journal of the American Geriatrics Society. 2003;51(4):443-450. Lewis LM, Miller DK, Morley JE, Nork MJ, Lasater LC. Unrecognized delirium in ED geriatric patients. American Journal of Emergency Medicine. 1995;13(2):142145. Naughton BJ, Moran MB, Kadah H, Heman-Ackah Y, Longano J. Delirium and other cognitive impairment in older adults in an emergency department. Annals of Emergency Medicine. 1995;25(6):751-755. Sanders AB. Missed delirium in older emergency department patients: a qualityof-care problem.[comment]. Annals of Emergency Medicine. 2002;39(3):338-341. Terrell KT, Hustey, F.M., Huang, U., et. al. Quality indicators for geriatric emergency care. Academic Emergency Medicine. 2009;16(5):441-449. Wilber ST, Lofgren SD, Mager TG, Blanda M, Gerson LW. An evaluation of two screening tools for cognitive impairment in older emergency department patients. Academic Emergency Medicine. 2005;12(7):612-616. Inouye SK. Delirium in older persons.[see comment][erratum appears in N Engl J Med. 2006 Apr 13;354(15):1655]. New England Journal of Medicine. 2006;354(11):1157-1165. Ely EW, Inouye SK, Bernard GR, et al. Delirium in mechanically ventilated patients: validity and reliability of the confusion assessment method for the intensive care unit (CAM-ICU). JAMA. Dec 5 2001;286(21):2703-2710.