Acute Confusional Syndrome - Delirium

Acute Confusional Syndrome (ACS) / Delirium Overview
📌 Acute Confusional Syndrome (ACS), also known as delirium, is a severe neuropsychiatric alteration characterized by an acute onset of attention deficit.
📊 Prevalence is 23% in adults over 65, rising to nearly 70% in the Intensive Care Unit (ICU) setting, especially during invasive mechanical ventilation.
🚨 ACS is a medical emergency due to increased risks of falls, aspiration pneumonia, inadvertent removal of venous access/feeding tubes, and potential mortality.

Risk Factors and Etiology
🔪 Major risk factors include surgical procedures (cardiovascular, abdominal, emergency procedures) and infections, which are the most frequent cause of ACS/delirium.
💧 Other common causes include dehydration, electrolyte imbalance, acute kidney injury, hepatic dysfunction, alcoholism (leading to delirium tremens), seizures, and heart failure.
💊 Factors specific to the ICU environment include prolonged stay, use of benzodiazepines, and physical restraints.

Pathophysiology Theories
🧠 The bioenergetic proposal suggests delirium results from inadequate ATP generation in the astrocyte-neuron unit, often due to inflammation affecting blood vessels or glucose transport issues, leading to metabolic support loss.
🔥 The inflammatory proposal involves inflammatory mediators (like interleukins and TNF) entering neurons, causing inflammation, substrate loss, and neuronal injury, with older patients having a lower threshold for cytokine response.
⚡ Disruption in the ascending reticular activating system (involving the locus coeruleus and raphe nuclei) impairs cholinergic activation reaching the thalamus and cortex, thus compromising cognitive functions like memory and attention.

Neurotransmitter Imbalances and Clinical Manifestations
📉 Neurotransmitter imbalances include a cholinergic deficit, elevated dopamine (due to glutamate excitotoxicity), and often decreased serotonin (especially in alcohol withdrawal).
📋 Clinical manifestations, based on DSM-5 criteria, include an acute disturbance in attention (difficulty focusing/sustaining), acute onset (hours/days), and an alteration in cognition (disorientation, language changes).
🗣️ Behavioral disturbances often classify delirium into hypoactive (most frequent but underdiagnosed), hyperactive, or mixed types, according to the Richmond Agitation-Sedation Scale (RASS) or similar criteria.

Diagnosis and Assessment Tools
🔎 Diagnosis requires identifying the acute, fluctuating deficit, lack of explanation by pre-existing disorders, and an identifiable somatic cause (intoxication, withdrawal, medication effect).
⭐ The CAM (Confusion Assessment Method) scale evaluates four core components: acute onset/fluctuating course, inattention, altered level of consciousness, and disorganized thinking, with scores of 1 & 2 or 3 & 4 highly suggestive of delirium.
🔬 Complementary studies include baseline labs (electrolytes, creatinine, glucose), drug/toxin levels, and, if no obvious cause is found, neuroimaging or lumbar puncture.

Differential Diagnosis and Treatment
🆚 Differential diagnoses include slowly progressive dementia, focal syndromes like Wernicke's aphasia, Anton's syndrome, and non-convulsive epilepticus (diagnosed via EEG).
🏥 Treatment pillars focus on managing the underlying medical cause and providing medical support (hydration, nutrition, mobility, pain management).
💊 For managing agitation, haloperidol (max $5 \text{ mg/day}$, IV preferred) is the drug of choice, but must be avoided in Parkinsonism due to extrapyramidal side effects.

Key Points & Insights
➡️ Acute onset and fluctuation are critical identifiers for ACS/delirium, differentiating it from chronic conditions like dementia.
➡️ In cases of agitation posing a risk to patient or staff safety, antipsychotics like haloperidol should be initiated; otherwise, focus on seeking the etiology.
➡️ Non-pharmacological measures are vital, including correcting modifiable risk factors like pain, discomfort, and ensuring sensory aids (glasses, hearing aids) and family contact are maintained.
💊 Benzodiazepines are reserved strictly for delirium related to alcohol withdrawal (delirium tremens) or when antipsychotics are contraindicated (e.g., Parkinsonism); lorazepam is an alternative.

📸 Video summarized with SummaryTube.com on Mar 12, 2026, 07:04 UTC