6 success steps for diagnosing altered level of consciousness

Focus on assessing and treating the patient's basic life threats before interrogating bystanders or investigating the scene


Patients with an altered level of consciousness are among the toughest to assess since there is no classic, "one size fits all" presentation.

The clinical presentation is often subtle, which makes recognizing changes in mental status a challenging endeavor. And, the underlying conditions that cause an ALOC have one of the largest differential diagnoses you may encounter in the prehospital setting.

Despite the many challenges, EMTs and paramedics who follow a structured approach with these patients are often able to find the cause and rule out worst-case scenarios. When you’re called to help someone who isn’t oriented to time, place or person, here are six ways to facilitate a successful patient contact.

1. Start with the ABCs

Use the SNOT mnemonic remember the most common causes for altered mental status.
Use the SNOT mnemonic remember the most common causes for altered mental status.

Avoid trying to discover the underlying reason for the patient’s ALOC before you do a primary assessment and treat any immediate life threats. If there is a deficit in one of the patient’s ABCs that isn’t the primary cause, it will certainly make the patient worse if left untreated.

An unstable airway will lead to hypoxia and central nervous system depression. Inadequate breathing will contribute to high levels of carbon dioxide in the blood and respiratory acidosis. Poor circulation will cause hypoperfusion in the brain.

Only after you’ve methodically checked a patient’s ABCs and treated any life threats, should you take a set of vital signs, inquire about the history of the present illness and obtain a SAMPLE history. 

2. Do a detailed physical exam

Performing a physical exam is often the key to ruling in — or out — a possible cause for a patient’s ALOC. For a stroke, look for a lack of movement on one side of the patient’s body, unequal pupils or the presence of the Babinski’s reflex (the big toe of an adult fanning upwards) by firmly stroking on the sole of the patient's foot with a pen or penlight.

Seizure patients may present with oral trauma or incontinence.

The skin of patients with hypoglycemia is often pale, cool and clammy. Patients with hyperglycemia often present with hot and dry skin.

Look for constricted pupils on patients who have overdosed on opiates and cyanosis in patients who are hypoxic.

To search for possible infection sources, scan the patient for signs of dialysis devices and catheters.

Always examine the patient to search for trauma and obtain an ECG to make sure a cardiac event isn’t causing the mental status changes.

3. Search for underlying causes

After you’ve completed a primary assessment, physical exam and obtained a set of vital signs, begin your detective work to find or confirm the underlying cause. An altered mental status is not a disease state in itself, but is always caused by some underlying factor.

If the mnemonic AEIOU-TIPS (acidosis, alcohol, epilepsy, infection, overdose, uremia, trauma, tumor, insulin, psychosis, stroke) is difficult to remember on-scene try something different. I use the mnemonic SNOT (stroke, seizure, sugar, narcotics, oxygen, trauma, toxins, telemetry/EKG). This mnemonic is easier for me to remember and lists the most common causes for an altered mental status. 

4. Interview multiple sources on scene

Since we can’t obtain reliable historical data from someone with an ALOC, enlist information from family members, friends, caretakers, nursing home workers and witnesses.

Begin by asking, "Is this normal for the patient?" which will immediately rule out dementia, Alzheimer’s or other pre-existing conditions that can cause chronic mental status changes.

Then, ask what they see different about the patient? Can they describe specifically how the patient is different? When did the change start and what they think might have caused it? Once you have this information, consider it in light of your other findings to discover a possible cause. 

5. Assess the environment

Every time you walk on scene — especially one involving an ALOC patient — take a moment to assess the environment and answer these questions.

  • Where was the patient found and in what position?
  • What are they wearing?
  • What objects, such as liquor bottles, medications or needles, surround the patient?

Over time, you’ll begin to see a correlation that sometimes exists between the environment and the chief complaint. For example, drug addicts often get high in out-of-the-way places such as bathrooms or vehicles.

Alleys are frequently the scene of assaults and someone who has a syncopal event after sitting on the toilet has often had a vagal episode, causing a drop in blood pressure and cerebral perfusion. 

6. Treat what you can and follow up

At the end of the day, EMTs and paramedics don’t need to know the exact cause for a patient’s ALOC in the prehospital setting. All we need to do is treat the symptoms we can treat using the tools we have and transport the patient rapidly to the hospital for definitive care.

However, don’t fall into the trap of letting the call end when you hand over patient care. Follow up with the ED staff to learn what tests they performed and what they discovered, and keep a journal to document your interesting calls.

By keeping the mentality of always being a student and never a master, you will continue to learn and grow throughout your EMS career.  

About the author

Kevin Grange works as a paramedic with Jackson Hole Fire/EMS and is the author of the new memoir about paramedic school, titled "Lights and Sirens: The Education of a Paramedic."

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