Laboratory Studies

Laboratory tests that may be helpful for diagnosis include the following:

Complete blood cell count with differential - Helpful to diagnose infection and anemia
Electrolytes - To diagnose low or high levels
Glucose - To diagnose hypoglycemia, diabetic ketoacidosis, and hyperosmolar nonketotic states
Renal and liver function tests - To diagnose liver and renal failure
Thyroid function studies - To diagnose hypothyroidism
Urine analysis - Used to diagnose urinary tract infection
Urine and blood drug screen - Used to diagnose toxicological causes
Thiamine and vitamin B-12 levels - Used to detect deficiency states of these vitamins
Tests for bacteriological and viral etiologies including syphilis
Sedimentation rate
Drug screen including alcohol level
HIV tests
Tests for other infectious causes if necessary or clinically indicated (These tests are not performed routinely, even though 30-40% of hospitalized patients with HIV infection develop delirium during hospitalization.^[32])
Serum marker for delirium: The calcium-binding protein S-100 B could be a serum marker of delirium. Higher levels are seen in patients with delirium when compared to patients without delirium.^[33]

Imaging Studies

See the list below:

Neuroimaging
- Perform CT scan of the head.
- Magnetic resonance imaging (MRI) of the head may be helpful in the diagnosis of stroke, hemorrhage, and structural lesions.
Electroencephalogram
- In delirium, generally, slowing of the posterior dominant rhythm and increased generalized slow-wave activity are observed on electroencephalogram (EEG) recordings.
- In delirium resulting from alcohol/sedative withdrawal, increased EEG fast-wave activity occurs.
- In patients with hepatic encephalopathy, diffuse EEG slowing occurs.
- The type of patterns observed includes triphasic waves in toxicity or metabolic derangement, continuous discharges in nonconvulsive status epilepticus, and localized delta activity in focal lesions.
Chest radiograph is used to diagnose pneumonia or congestive heart failure.

Other Tests

Lumbar puncture is indicated when CNS infection is suspected as a cause of delirium or when the source for the systemic infection cannot be determined.

Pulse oximetry is used to diagnose hypoxia as a cause of delirium.

Electrocardiogram is used to diagnose ischemic and arrhythmic causes.

Treatment & Management

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Author

Kannayiram Alagiakrishnan, MD, MBBS, MPH, MHA Professor, Department of Medicine, Division of Geriatric Medicine, University of Alberta Faculty of Medicine and Dentistry, Canada

Kannayiram Alagiakrishnan, MD, MBBS, MPH, MHA is a member of the following medical societies: American College of Physicians, American Geriatrics Society

Disclosure: Nothing to disclose.

Specialty Editor Board

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Received salary from Medscape for employment. for: Medscape.

Chief Editor

Glen L Xiong, MD Associate Clinical Professor, Department of Psychiatry and Behavioral Sciences, Department of Internal Medicine, University of California, Davis, School of Medicine; Medical Director, Sacramento County Mental Health Treatment Center

Glen L Xiong, MD is a member of the following medical societies: AMDA - The Society for Post-Acute and Long-Term Care Medicine, American College of Physicians, American Psychiatric Association, Central California Psychiatric Society

Disclosure: Serve(d) as a director, officer, partner, employee, advisor, consultant or trustee for: SafelyYou, Blue Cross Blue Shield, Included Health<br/>book co-editor for: Wolter Kluwer, American Psychiatric Publishing Inc.

Additional Contributors

Mohammed A Memon, MD Psychiatrist/Geriatric Psychiatrist, Carolina Center for Behavioral Health; Assistant Professor of Psychiatry, Virginia Commonwealth University School of Medicine

Mohammed A Memon, MD is a member of the following medical societies: American Association for Geriatric Psychiatry, American Medical Association, American Psychiatric Association

Disclosure: Nothing to disclose.

Acknowledgements

Patricia Blanchette, MD Department Chair and Director, Geriatric Medicine Fellowship Program, Professor of Geriatric Medicine, John A Burns School of Medicine, University of Hawaii

Patricia Blanchette, MD is a member of the following medical societies: American College of Physicians, American Geriatrics Society, American Medical Association, American Medical Directors Association, Gerontological Society of America, and Hawaii Medical Association

Disclosure: Nothing to disclose.

Sections Delirium
Overview
Presentation
- History
- Physical
- Causes
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DDx
Workup
Treatment
Guidelines
Medication
Follow-up
Questions & Answers
Tables
References

Features	Delirium	Dementia
Onset	Acute	Insidious
Course	Fluctuating	Progressive
Duration	Days to weeks	Months to years
Consciousness	Altered	Clear
Attention	Impaired	Normal, except in severe dementia
Psychomotor changes	Increased or decreased	Often normal
Reversibility	Usually	Rarely

Delirium Workup

Laboratory Studies

Imaging Studies

Other Tests

References

Tables

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