How should I assess for alcohol‑related delirium (delirium tremens) in a patient with recent heavy alcohol use?

Assessment of Alcohol-Related Delirium (Delirium Tremens)

Alcohol-related delirium (delirium tremens) is diagnosed clinically by documenting acute onset of confusion, disorientation, and hallucinations occurring 48–72 hours after alcohol cessation in a patient with recent heavy alcohol use, combined with autonomic hyperactivity (tachycardia, hypertension, fever, tremor, diaphoresis) and fluctuating level of consciousness. 1, 2

Timeline and Clinical Presentation

Early Withdrawal Phase (6–24 hours)

• Autonomic hyperactivity develops first: tremor (especially hands), tachycardia, hypertension, diaphoresis, anxiety, agitation, irritability, headache, nausea, and vomiting 2, 3, 4
• Hyperreflexia is commonly observed during this early phase 4

Progression to Delirium Tremens (48–72 hours, peak days 3–5)

• Delirium tremens typically begins 48–72 hours after the last drink, with peak severity at days 3–5 2, 4, 5
• Hallucinations (typically visual) may appear at 12–24 hours in 2–8% of patients 4
• Seizures occur in up to 15% of patients between 12–48 hours after cessation 4, 5
• Delirium tremens develops in 3–5% of patients with alcohol withdrawal, carrying mortality up to 50% if untreated 4, 6

Core Diagnostic Features of Delirium Tremens

Mental Status Changes

• Acute onset and fluctuating course of confusion and disorientation 1, 6
• Impaired level of consciousness with altered arousal 1
• Inattention and disorganized thinking 1
• Memory impairment and language disturbances 1

Behavioral and Perceptual Disturbances

• Visual, auditory, or tactile hallucinations 1, 6
• Delusions and misperceptions 1
• Severe agitation or inappropriate/unsafe behavior 1, 6
• Emotional lability 1

Autonomic Instability

• Severe tachycardia and hypertension 6, 5
• High fever and profuse sweating 6
• Marked tremor 6, 5

Temporal Pattern

• Symptoms fluctuate within minutes to hours 1
• Sleep–wake cycle disturbances are prominent 1

Essential Clinical Assessment Steps

Establish Baseline Cognitive Function

• Interview a knowledgeable informant to determine the patient's previous baseline cognition, function, and behavior 1
• Document the time course, nature, and trajectory of mental status changes 1
• This baseline comparison is the foundation of delirium diagnosis 1

Quantify Alcohol Use History

• Calculate average drinks per week over time using standard drink equivalents (14 g ethanol = 1 standard drink in the US) 1
• Document duration of heavy use (>80 g/day for ≥10 years increases risk) 7
• Ask about morning drinking and prior withdrawal episodes 1, 8
• Use structured tools like AUDIT-C for systematic assessment 1

Perform Serial Cognitive Assessments

• Use a validated brief instrument such as the Confusion Assessment Method (CAM) to establish current cognitive performance 1
• Repeat assessments frequently because mental status fluctuates substantially within a day 1
• The CIWA-Ar scale quantifies withdrawal severity (score ≥8 indicates need for treatment; ≥15 indicates severe withdrawal) 7

Monitor Vital Signs Continuously

• Assess for autonomic instability: tachycardia, hypertension, fever, sweating 3, 7
• Close monitoring during the 48–72 hour window when delirium tremens risk is highest is essential 2

Critical Differential Diagnoses to Exclude

Wernicke Encephalopathy

• Presents with confusion, disorientation, ataxia, and ophthalmoplegia in alcohol-dependent patients 7
• Can develop days to weeks after cessation if thiamine was not supplemented 7
• This is a medical emergency requiring immediate high-dose thiamine (100–500 mg IV) before any glucose administration 7, 4

Hepatic Encephalopathy

• Confusion with asterixis-type tremor in patients with underlying alcoholic liver disease 7
• Can be triggered by alcohol cessation, dehydration, or electrolyte imbalances 7

Other Medical Complications

• Hypoglycemia (check finger-stick glucose immediately) 4
• Electrolyte disturbances, especially hypomagnesemia 3, 7
• Infection or sepsis 7, 6
• Gastrointestinal bleeding 7
• Pancreatitis 7
• Subdural hematoma or other trauma 4

Laboratory and Imaging Evaluation

• Complete blood count (CBC) and complete metabolic panel (CMP) 4
• Magnesium level (commonly depleted in chronic alcohol use) 3, 7
• Liver function tests (AST typically 2–6× upper limit; AST/ALT ratio >2 suggests alcoholic liver disease) 1
• CT scan of the brain if trauma suspected or focal neurologic findings present 4
• Blood alcohol level and urine drug screen 4

Common Pitfalls to Avoid

• Failure to recognize early progression signs can lead to rapid deterioration to life-threatening complications 2
• The highest risk period for delirium tremens is days 2–5, not the first day 2
• Do not assume symptoms starting >6 days after cessation are alcohol withdrawal; consider Wernicke encephalopathy or hepatic encephalopathy 7
• Hypoactive delirium (with sedation and motor slowing) is more common in older individuals and carries greater mortality risk but is easily missed 1
• Subsyndromal delirium from sleep disturbances or cognitively deleterious medications can decompensate patients with underlying cognitive impairment 1