Stepwise Evaluation of a Patient with Delirium

from Harrison’s Principles of Internal Medicine, 21e

Initial Evaluation

• History with special attention to medications (including over-the-counter and herbals)
• General physical examination and neurologic examination
• Complete blood count
• Electrolyte panel including calcium, magnesium, phosphorus
• Liver function tests, including albumin
• Renal function tests

First-Tier Further Evaluation Guided by Initial Evaluation

Systemic infection screen - Urinalysis and culture - Chest radiograph - Blood cultures Electrocardiogram Arterial blood gas Serum and/or urine toxicology screen (perform earlier in young persons) Brain imaging with MRI with diffusion and gadolinium (preferred) or CT Suspected CNS infection or other inflammatory disorder: lumbar puncture after brain imaging Suspected seizure-related etiology: electroencephalogram (EEG) (if high suspicion, should be performed immediately)

Second-Tier Further Evaluation

• Vitamin levels: B12, folate, thiamine
• thyroid-stimulating hormone (TSH) and free T4; cortisol
• Serum ammonia
• Sedimentation rate
• antinuclear antibodies (ANA), complement levels; p-ANCA, c-ANCA, consider paraneoplastic/autoimmune encephalitis serologies
• rapid plasmin reagin (RPR); fungal and viral serologies if high suspicion; HIV antibody

Lumbar puncture (if not already performed) Brain MRI with and without gadolinium (if not already performed)