Delirium: The Great Pretender

Sam Cooke’s rendition of The Great Pretender.

Recently we had a very nice presentation at one of our Clinical Problems in Consultation Psychiatry (CPCP). A summary of the CPCP purpose and structure is:

Clinical Problems in Consultation Psychiatry (CPCP):

A weekly case conference held Wednesdays from 8:00 a.m. to approximately 8:45 a.m. Each week, a case is selected from the Daily Review Rounds Records to illustrate a clinical problem for the next week’s meeting.  The residents are assigned dates when they rotate. The medical students are welcome and even encouraged to participate as well.

This is a practical way to approach teaching the Practice-Based Learning & Improvement Core Competency. This helps develop the habit of reflecting on and analyzing one’s practice performance; locating and applying scientific evidence to  the care of patients; critically appraising the medical literature; using the computer to support learning and patient care; facilitating the education of other health care professionals. This is applying principles of evidence-based medicine (EBM) to clinical practice.

  • Evidence-based medicine is a systematic approach to use up to date information in the practice of medicine
  • Skills are needed to integrate the available evidence with clinical experience and patient concerns
  • Application and evaluation of EBM skills will provide a frame-work for life-long learning.

Self-evaluation is vital to the successful practice of EBM:

  • Am I asking answerable clinical questions?
  • Am I searching the literature?
  • Am I becoming more efficient in my searches?
  • Am I integrating my critical appraisals into my practice?

The assigned resident is responsible for searching the literature and selecting one or two teaching papers for the conference. Presentations will begin with a review of the case, followed by a summary of the references with subsequent round table discussion.

Circulate copies of 2-4 pertinent articles to team members including psychiatric nurses and faculty. A copy machine is available in the departmental administration office. Consult staff can also assist with obtaining copies.

Presentations begin with a 5-minute summary of the case with discussion of both psychiatric and medical aspects of evaluation and management. The remaining time is spent summarizing the pertinent data in the articles. Residents and medical students are encouraged to use the case conference material as preparation for submitting a case report or letter to the editor.

Dr. Ben PerryThe most recent CPCP was given by one of the Family Medicine resident physicians, Dr. Benjamin Perry, MD, MBA. Often the family medicine residents have a month-long experience on the psychiatry consultation service. They enjoy it and learn a lot. At least that’s what they tell me. Dr. Perry’s outline follows.


Dr. Perry’s presentation could have been entitled “Delirium, The Great Pretender.” His handout led with the introductory line “The Great Pretender” and Dr. Perry is right on target. I did not coach him. He pointed out that delirium mimics just about every primary psychiatric illness you can think of.

Delirium has gone by many different names including but not limited to:

  1. Acute confusional state
  2. Organic brain syndrome
  3. Toxic metabolic state
  4. Organic psychosis
  5. Encephalopathy
  6. Acute brain failure
  7. Cerebral insufficiency
  8. Depression
  9. ICU psychosis
  10. Sundowning
  11. Terminal restlessness (referring to delirium at the end of life, when many organ systems shut down)

The Diagnosis of Delirium per the Diagnostic and Statistical Manual (DSM-IV-TR):

  • Disturbance of consciousness with reduced ability to focus, sustain, or shift attention.
  • Change in cognition (i.e., memory deficit, disorientation, language disturbance) or perceptual disturbance not accounted for by preexisting, established, or evolving dementia.
  • Disturbance develops over short period of time and tends to fluctuate over course of day
  • Evidence from history, physical exam, or laboratory findings that disturbance caused by direct physiological consequences of general medical condition

Risk Factors:

  • Vision or hearing impairment
  • Physical restraints
  • Metabolic abnormalities
  • Previous episodes of delirium
  • Multiple medical comorbidities
  • Malnutrition
  • Alcohol abuse
  • Epidural anesthesia
  • Premorbid cognitive impairment
  • Polypharmacy (greater than 3 new medications added during acute hospitalization)
  • History of smoking
  • Constipation
  • Age greater than 70 years old
  • Hypertension or Chronic Obstructive Pulmonary Disease
  • Foley catheter or other medical restraining devices
  • Preoperative benzodiazepines and opioids

Causes: Mnemonic “I WATCH DEATH”:

  • Infection/Inflammation/Iatrogenic (rheumatologic, constipation)
  • Withdrawal states
  • Acute metabolic derangements (hypomagnesemia, hypercalcemia)
  • Trauma
  • Central nervous system pathology (stroke, hemorrhage, tumor, seizures, infection)
  • Hypoxia
  • Deficiencies (thiamine, B12, folate)
  • Endocrine (hypoglycemia, diabetic ketoacidosis, thyroid, adrenal, parathyroid disease)
  • Acute myocardial infarction or vascular events
  • Toxins or drugs (anticholinergics, sedatives, steroids)
  • Heavy metals (arsenic, lead, mercury)


Why it is important to recognize and systematically screen for delirium:

  • Common condition (20-30% in general medical setting, as high as 80% in ICU setting)
  • Increased mortality (6-month mortality as high as 25%)
  • Increased morbidity (higher risk of anxiety, PTSD)
  • Increased costs (increased length of stay, increased readmission rates, increased nursing home transfers)
  • Distress for families (lower quality of life, more anxiety, greater burden of decision-making)

How to Detect: See link Delirium Screening Scales Pounding Down the Home Stretch: The Delirium Observation Screening Scale and the Nursing Delirium Screening Scale Nose to Nose? « The Practical Psychosomaticist: James Amos, M.D.

  • Confusion Assessment Method (CAM, by Sharon Inouye and colleagues; 4 domains, requires 1 & 2, 3 or 4)
  • Delirium Detection Scale (DDS–cutoff score of 8)
  • Delirium Observation Screening Scale (DOSS–25 item and 13 item–cutoff score of 3)
  • Nursing Delirium Screen Scale (Nu-DESC–5 items with cutoff score of 2)
  • CAM-ICU (specifically for ICU patients)

Many thanks for getting it right, Dr. Perry!



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