Chapter 6: Delirium
Objectives:
- Define the term delirium
- Compare and contrast hyperactive delirium and hypoactive delirium
- Develop a workup and treatment plan for patients presenting with delirium
- Differentiate delirium from dementia and depression based on symptoms and clinical course
Delirium
Delirium is defined as a disturbance in mental abilities that results in confused thinking and reduced awareness of one’s environment. The evolution of delirium is often quite rapid and can develop within hours (i. e. it is an acute presentation). Some of the most common infectious causes that precipitate delirium (i.e. toxic metabolic encephalopathy) include pneumonia, urinary tract infections, influenza, and meningitis.
A diagnosis of delirium can be made utilizing the Confusion Assessment Method (CAM). The four parts of this assessment include:
- Acute onset
- Fluctuating course
- Inattention
- Disorganized thinking
Delirium is present if items 1 and 2 PLUS item 3 or item 4 are present. There is an associated 50% mortality rate associated in the next year for a patient diagnosed with delirium. As part of the physical exam, in addition to heart, lungs, and abdomen assessments, one should also evaluate cognitive assessment using the MOCA instrument as well as a detailed genitourinary exam and neurological exam including described in Chapter 4 (included here for convenience):
Genitourinary system:
- Assessment of suprapubic pressure
- Assessment of costovertebral angle tenderness
Nervous (central and peripheral) system:
- Cranial nerves: assess each level vs. gross function
- Muscle strength of upper and lower extremities
- Deep tendon reflexes of upper and lower extremity of biceps, brachialis, triceps, patellar, Achilles reflexes
- Coordination:
- Finger-to-nose
- Heel-to-shin
- Tandem walking (i.e. heel-to-toe)
- Timed get up and go test
- Cognitive testing: MOCA (or part of it, i.e. digit span)
If one suspects meningitis (since both pneumonia and meningitis are caused by Streptococcus pneumoniae, and S. pneumoniae is the most common cause of meningitis in patients over age 65), the presence of Kernig’s sign and Brudzinski’s sign should be evaluated. A positive test of either sign is an indication of irritation and inflammation of the meninges. Kernig’s sign is done by flexing the hip to 90o and extending the knee; the test is positive if the patient experiences back pain. Testing for Brudzinski’s sign is positive if the patient’s knees flex when the head is lifted with the patient in the supine position. A positive result for either of these tests warrants further workup for meningitis.
The treatment of delirium should be directed at treating the underlying cause. The most common causes of delirium include medications (anticholinergics, benzodiazepines, opioids, steroids), alcohol and illicit drug use and withdrawal, dehydration, infections (causing toxic metabolic encephalopathy), and electrolyte disturbances. Admission to the hospital is likely if from the community; nursing homes can treat most infections in place but occasionally hospital transfer is required. Hospital transfers can precipitate or worsen delirium.
Hyperactive delirium is characterized by agitation, picking at the clothes and bed covers, and rambling or loud incoherent speech. Behavior changes in patients with dementia are often due to an underlying physical (not mental) illness and may be due to underlying infection leading to superimposed delirium. Hypoactive delirium is associated with quiet, somnolence, little spontaneous movement, and soft or incoherent speech. Additionally, approximately 50% of patients at the end of life will often experience hypoactive delirium while actively dying.
The treatment plan and workup of delirium should involve the use of empiric broad-spectrum antibiotics while awaiting cultures, blood and urine cultures, CBC and BMP laboratory studies, chest X-ray, and IV fluids. Non-pharmacologic measures should include having in the patient’s room a white board with date, a large clock, the patient being provided with glasses and hearing aids, and cerumen disimpaction. Delirium progression or resolution can be assessed using the MOCA. One should see improvement without underlying dementia during treatment of the delirium course.
| Example: Delirium |
|---|
| An 80-year-old female presents to her primary care physician for evaluation of acute confusion with her son. Her son notes that she was in her usual state of health two days ago when he last spoke with her. However, this morning, when he called his mother on the phone, she kept saying that she had to catch a bus to go work, despite the fact that she has not worked in 15 years. She has had no sick contacts. She does complain of pain and pressure “down below” that started one day ago. She notes that she is urinating much more frequently than usual and describes an urge to go immediately. She denies any coughing or neck stiffness. Her son is unable to provide additional history as the patient lives alone. She has had no recent medication changes. Her past medical history is notable for hypertension without any cardiac or renal manifestations and diabetes mellitus type 2 which is very well controlled. She has no previous surgeries. She does not smoke or drink. Her home medications include amlodipine and metformin. She has no drug allergies. Her vital signs show the following: BP 130/86, HR 104, RR 18, T 99.6 F, sat 96% in room air. What is the etiology of her symptoms?
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Review Questions
Questions 1-3: A 79-year-old female and her daughter are seen in the emergency department. The patient lives at home with her daughter. Her daughter became concerned when the patient woke her up from her sleep at 4 AM telling her she couldn’t find her dress clothes to go to work despite being a retired corporate executive for the last 10 years. Her daughter notes that her mother was urinating more frequently than usual the day prior to admission and that she also noted a cough. The patient’s medical history is notable for bladder prolapse for which she had a pessary exchange three days ago. Functionally, she is independent of all of her activities of daily living and instrumental activities of daily living. She lives with her divorced daughter and assists with childcare of her three children and also light housework. Her vital signs reveal a blood pressure of 90/60 mm Hg, a temperature of 101.3 F, a respiratory rate of 22, a heart rate of 96, and an oxygen saturation of 97% without any supplemental oxygen. Her physical exam reveals decreased breath sounds bilaterally at the lung bases. She also demonstrates suprapubic tenderness and costovertebral angle tenderness. When the patient is asked where she is, she states that “I am in a beautiful hotel!” Throughout the encounter, she falls asleep and wakes up sporadically.
1. In order to assess this patient for delirium, which of the following components of the Montreal Cognitive Assessment is used?
A. Visuospatial/Executive
B. Naming
C. Registration/Recall
D. Digit span
E. Language
2. What organism is most likely implicated in this patient’s acute illness?
A. Proteus mirabilis
B. Klebsiella pneumonia
C. Staphylococcus aureus
D. Escherichia coli
E. Pseudomonas aeruginosa
3. Which of the following is the most appropriate first-line treatments for the treatment of hypoactive delirium?
A. Olanzapine
B. Risperidone
C. Haloperidol
D. Lorazepam
E. Non-pharmacological treatments
4. A 79-year-old female who is a resident of a long-term care facility due to Alzheimer’s disease is noted by nursing to have behavior changes including hallucinations and worsening agitation, including refusal of personal care and refusal of medications. Nursing requests the attending physician to evaluate the resident. What is the primary reason that new behaviors in patients with dementia require thorough evaluation?
A. Behavior changes are often an indication of worsening behavioral disturbances.
B. Behavior changes are often an indication of an underlying infection and may be due to delirium.
C. Behavior changes are an indication for physical restraints which require a physician to order.
D. Extreme behavior changes are expected during the progression of Alzheimer’s disease.
E. Behavior changes can lead to physical altercations and injury to the resident and other residents.
Answers to Review Questions
- D
- D
- E
- B