What is the workup for delirium (acute confusional state)?

From the Guidelines

The workup for delirium should begin with a thorough history and physical examination to identify potential underlying causes, and should include the use of standardized assessment tools such as the Confusion Assessment Method (CAM) or the Intensive Care Delirium Screening Checklist (ICDSC) 1.

Key Components of the Workup

• Start with vital signs, mental status assessment, and a complete neurological examination
• Laboratory tests should include:
  • Complete blood count
  • Comprehensive metabolic panel
  • Urinalysis
  • Blood cultures if infection is suspected
  • Thyroid function tests
  • Vitamin B12 levels
  • Toxicology screening
• Imaging studies should include:
  • Chest X-ray to rule out pneumonia
  • Head CT or MRI to exclude stroke, hemorrhage, or mass lesions
• An electroencephalogram (EEG) may be useful to rule out seizures or encephalitis
• Lumbar puncture should be considered if meningitis or encephalitis is suspected
• Medication review is crucial as many drugs can cause delirium, particularly in elderly patients

Prevention and Treatment

• Non-pharmacological interventions such as multimodal sensory, cognitive, and emotional stimulation, and interventions for reduction of stress, improvement of communication, and family care should be implemented to prevent delirium 1
• Haloperidol should not be used as a prophylactic treatment for ventilated patients, as it has been shown to have no effect in incidence, severity, duration, or outcome of delirium 1

Common Causes of Delirium

• Infections (especially urinary tract infections and pneumonia)
• Metabolic disturbances
• Drug toxicity
• Alcohol withdrawal
• Acute organ failure The workup should be tailored to the patient's clinical presentation and risk factors, with the goal of identifying and treating the underlying cause while providing supportive care to manage symptoms 1.

From the Research

Delirium Workup

• Delirium is a complex condition that requires a thorough workup to determine its underlying etiology and to maximize the potential for reversibility 2.
• A full history, physical examination, and investigations should be performed to detect delirium, as many cases are reversible 2.
• The pathophysiologic cause of delirium is not well understood, and there is no single intervention or medication to treat it, making it challenging to manage 3.
• Risk mitigation and prompt treatment rely on a sophisticated strategy to address the contributing factors, and multimodal strategies may prevent or attenuate delirium, improving patient outcomes 3.

Diagnostic Approaches

• The diagnostic accuracy of approaches to identify delirium, including history, physical examination, laboratory testing, and screening instruments, has been quantified in a systematic review 4.
• The 4 A's Test (4AT) has been found to be accurate in ruling in and ruling out delirium, with a pooled positive likelihood ratio of 7.5 and a pooled negative likelihood ratio of 0.18 4.
• The Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) has been found to be superior in ruling in delirium, while the Delirium Triage Screen is superior in ruling out delirium 4.

Clinical Suspicion and Workup

• Clinical suspicion of comorbid delirium is a strong predictor of a more thorough general medical workup in cases of catatonia 5.
• Attribution of catatonia to a psychiatric etiology is associated with significantly less diagnostic workup, highlighting the importance of considering delirium in the diagnostic approach to patients presenting with catatonia 5.