From the Guidelines
The initial workup for a patient presenting with acute confusion should begin with a thorough history and physical examination, focusing on vital signs, neurological assessment, and identifying potential triggers, as recommended by the most recent guidelines 1. The workup should include laboratory tests such as complete blood count, comprehensive metabolic panel, urinalysis, blood glucose, thyroid function tests, and toxicology screening.
- Imaging studies such as a head CT or MRI may be necessary to rule out structural causes.
- Additional tests to consider include electrocardiogram, chest X-ray, arterial blood gases, and lumbar puncture if infection is suspected.
- Medication review is crucial as many drugs can cause confusion, particularly in elderly patients, as noted in the geriatric emergency department guidelines 1. The workup aims to identify and address reversible causes of confusion, which commonly include:
- Infections (especially urinary tract infections and pneumonia)
- Metabolic disturbances (electrolyte abnormalities, hypoglycemia, organ failure)
- Medication effects
- Substance withdrawal
- Neurological events Oxygen saturation should be monitored and supplemental oxygen provided if needed, as emphasized in the management of agitated delirium 1. This systematic approach is essential because acute confusion (delirium) is often a symptom of an underlying medical condition requiring prompt identification and treatment to prevent complications and improve outcomes, with a high mortality rate of approximately 8.1% if left undiagnosed or untreated 1.
From the Research
Initial Workup for Acute Confusion
The initial workup for a patient presenting with acute confusion involves a comprehensive evaluation to identify the underlying cause. Some key considerations include:
- Medical history and physical examination to identify potential causes such as infections, metabolic disorders, or neurological conditions
- Laboratory tests, such as complete blood count, blood chemistry, and urinalysis, to help identify underlying conditions 2, 3
- Assessment for potential adverse drug reactions, particularly those affecting the urinary tract, as certain medications can contribute to confusion 4
Potential Causes and Associations
Some studies suggest that:
- Urinary tract infections (UTIs) are commonly associated with confusion in nursing home residents, and antibiotic treatment for suspected UTIs is often linked to confusion 2
- Certain medications, including anticholinergic agents, can cause urinary retention and other adverse reactions that may contribute to confusion 5, 4
- A thorough evaluation of the patient's medication regimen and potential drug interactions is essential in the workup for acute confusion
Diagnostic Approach
A step-wise approach to diagnosis, as outlined in studies on diagnostic strategies and test algorithms, can help guide the evaluation of patients with acute confusion 6. This approach involves:
- Developing a problem list based on the patient's history, physical examination, and basic laboratory studies
- Synthesizing and analyzing the information to develop a differential diagnosis with associated disease probabilities
- Selectively using diagnostic tests to rule in or rule out potential causes of confusion