ALTERED MENTAL STATUS

In this episode of the Audioboards we take a deep dive into Altered Mental Status (AMS) — one of the most challenging and high-stakes presentations in medicine. From hypoglycemia and opioid overdose to stroke, sepsis, toxicologic emergencies, and brainstem pathology, AMS can represent a wide spectrum of life-threatening conditions.

We break down the systematic ABCDEF approach to stabilization, discuss critical neurologic assessment pearls, explore the broad differential diagnosis using practical frameworks, and compare delirium, dementia, and psychosis in the emergency setting. 

Transcript

Welcome back to the Audioboards. Today we’re talking about altered mental status— one of the most important and high-risk presentations in medicine. And honestly, it can be intimidating because it’s not a diagnosis itself. It’s a symptom. It can represent something relatively simple and reversible like hypoglycemia, or something catastrophic like sepsis, stroke, intracranial hemorrhage, or impending brain herniation.

So the key challenge for clinicians is figuring out three things quickly: what’s reversible, what’s life-threatening, and what needs immediate intervention.

By definition, AMS is an acute change in cognition, psychological function, or level of consciousness. Patients may present confused, lethargic, agitated, hyperalert, somnolent, or completely unresponsive.

So basically AMS can look completely different depending on the underlying cause?

Exactly. That’s what makes it challenging. There’s no single presentation. One patient may be quietly delirious, another may be combative and hallucinating, and another may simply appear sleepy or withdrawn.

Whenever you encounter an Altered patient, your first job is stabilization. Before you worry about the exact diagnosis, you need to identify immediate life threats and reversible causes. That starts with the ABCDEF approach while the patient is being placed on monitors, IV access is being obtained, and vital signs are being collected.

Let’s start with the airway. First ask: is the airway open, and is the patient protecting it? Are there secretions, vomit, or blood that need suctioning? Pulse oximetry should be applied immediately, and supplemental oxygen given if hypoxia is present.

Remember this: hypoxia is one of the most important reversible causes of altered mental status.

So oxygenation is one of the very first things you correct?

Absolutely. Next comes breathing. Assess respiratory rate, work of breathing, and end-tidal CO2 if available. Hypoventilation causes CO2 retention, which leads to respiratory acidosis and worsening mental status.

If ventilation is inadequate, the patient may require positive pressure ventilation. And anytime AMS is associated with respiratory depression, opioid overdose should move very high on your differential.

Because opioids suppress respiratory drive.

Exactly.

Now circulation. Assess pulses, blood pressure, cardiac rhythm, perfusion, and skin findings. Ask yourself: does the patient look warm or cool? Diaphoretic? Shocky?

Poor cerebral perfusion rapidly causes AMS. Nonperfusing rhythms require CPR and ACLS immediately. Hypotension should trigger IV fluids and an investigation into the cause of shock.

And this is where POCUS — point-of-care ultrasound — can be incredibly useful early on.

Next comes disability, meaning your rapid neurologic evaluation. Use either the Glasgow Coma Scale or the AVPU scale, which is Alert, Responds to Voice, Responds to Pain, Unresponsive

Look carefully for seizure activity or postictal signs like tongue trauma, incontinence, fasciculations, or nystagmus.

Assess pupils, cranial nerves, spontaneous movement, and focal deficits. Hemiparesis could indicate stroke. Paralysis below a certain level could suggest spinal cord pathology.

And here’s a major pearl: Altered plus cranial nerve abnormalities should be considered a brainstem lesion until proven otherwise.

That’s a really important point.

It definitely is. And if trauma is suspected, cervical spine stabilization is essential.

Then comes exposure. Fully undress the patient and examine everything. Look for trauma, needle marks, fentanyl patches, dialysis access, pressure ulcers, petechiae, cellulitis, or other hidden clues.

And always assess temperature. Both hypothermia and hyperthermia can cause AMS.

Finally — fingerstick glucose. Never skip this step. Hypoglycemia is common, deadly, and rapidly reversible.

The differential diagnosis for AMS is huge, but organizing it into categories makes it manageable.

Think about:

Structural causes

Metabolic causes

Toxicologic causes

Infectious causes

Hemodynamic causes

Psychiatric causes

Structural causes include stroke, intracranial hemorrhage, tumors, hydrocephalus, seizures, and dementia.

One important concept: isolated structural lesions usually don’t cause depressed consciousness unless the brainstem or both cerebral hemispheres are involved.

Metabolic causes are extremely common:

Hypoglycemia

Hyperglycemia

Sodium abnormalities

Calcium abnormalities

Hypoxia

Hypercarbia

Uremia

Hepatic encephalopathy

Hypothyroidism

Temperature abnormalities

Toxicologic causes are also incredibly common, especially in older adults. Think sedatives, opioids, anticholinergics, alcohol intoxication, toxic alcohols, overdoses, withdrawal states, and polypharmacy.

Infectious causes include meningitis, encephalitis, pneumonia, UTIs, cellulitis, abdominal infections, and sepsis.

And remember: elderly patients may present with AMS as the only sign of serious infection.

Three major syndromes commonly associated with AMS are delirium, dementia, and psychosis — and distinguishing between them is critical.

Delirium is a true medical emergency. It presents with acute onset, fluctuating course, inattention, altered awareness, and cognitive dysfunction.

Most delirium is caused by an underlying toxic, metabolic, infectious, or medication-related illness. The prognosis is poor if untreated.

Dementia is different. It’s usually a slow and progressive decline in cognition with relatively preserved consciousness.

One of the most important questions is: “What is this patient’s baseline?” Collateral history becomes absolutely essential here.

Psychosis involves hallucinations, delusions, and loss of insight. Unlike delirium, orientation is often preserved. Management focuses on reducing stimulation, maintaining a calm environment, and communicating respectfully.

And it’s dangerous to assume every agitated patient has a psychiatric issue before ruling out medical causes.

Exactly right.

Altered patients often cannot provide reliable histories, which makes collateral information critical. Family members, EMS personnel, nursing home staff, and witnesses can help determine whether symptoms were sudden or gradual, fluctuating or constant, and whether there were medication changes, falls, substance use, or prior episodes.

For delirium screening, CAM-ICU is very useful. Acute fluctuating course plus inattention and either disorganized thinking or altered consciousness strongly suggests delirium.

Metabolic evaluation may include:

Glucose

Electrolytes

Calcium

Renal function

Blood gas analysis

Thyroid studies

Ammonia

Cortisol

Toxicology testing may include:

ECG

Drug screens

Medication levels

Ethanol level

Serum osmolality

Infectious workup may include:

CBC

Blood cultures

Lactate

Urinalysis

Chest X-ray

Lumbar puncture when indicated

If elevated intracranial pressure is suspected, obtain CT imaging before lumbar puncture.

Neurologic imaging usually starts with CT head, while MRI is useful for posterior circulation or brainstem pathology. EEG may be necessary for suspected nonconvulsive status epilepticus.

Treatment always focuses on correcting the underlying cause. Hypoglycemia is treated with dextrose, but remember that D50 contains only about 100 calories, so recurrent hypoglycemia can occur if patients are not fed appropriately afterward.

Opioid overdose is treated with naloxone, but patients require observation because naloxone has a shorter half-life than many opioids, especially methadone.

Withdrawal states often require supportive care and sedation. Excited delirium is a true emergency associated with high mortality.

Infectious causes require early antibiotics and sepsis management.

Severe symptomatic hyponatremia may require hypertonic saline, but rapid correction must be avoided because of the risk of osmotic demyelination syndrome.

And Wernicke encephalopathy should always be treated with thiamine.

What if my patient wants to leave against medical advice.

One of the hardest situations is when AMS patients want to leave against medical advice.

The key question becomes: does the patient have decision-making capacity?

Can they understand:

The risks of leaving

The benefits of staying

The consequences of refusing care

When uncertainty exists, err on the side of patient safety, involve family whenever possible, and document your reasoning thoroughly.

Ultimately, altered mental status should always be approached with urgency and broad clinical thinking. Delirium is a medical emergency, collateral history is invaluable, and reassessment is critical throughout the patient’s course. Small details often reveal the diagnosis, and rapidly identifying reversible causes can truly save lives.

Thanks for listening to AudioBoards. Stay tuned for more educational content in our next episode! The views and opinions expressed on the AudioBoards Podcast do not necessarily reflect those of our employers. This podcast is for educational purposes only and should not be used to diagnose or treat any medical conditions. It is not a substitute for professional medical advice. Always consult a qualified, board-certified healthcare provider for any medical concern.