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C3 - Altered Mental Status - Part 1

Mel Herbert, MD MBBS FAAEM, Stuart Swadron, MD, FRCPC, and Mizuho Spangler, DO

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C3 - Altered Mental Status - Part 1 - Summary 258 KB - PDF

The differential diagnosis for altered mental status is extremely broad. Stuart Swadron MD and Mizuho Spangler DO discuss the most common causes of AMS and review a practical approach to initially assessing a patient with undifferentiated AMS.


Altered Mental Status - Part I - Basic Approach and Critical Initial Diagnoses

Stuart Swadron, Mizuho Spangler, Mel Herbert, Jessica Mason


Definition: Altered mental status has many definitions but fundamentally involves changes in a person’s alertness, attention, memory, and/or awareness.  Oftentimes, a patient is brought in with the chief complaint of “he/she is not acting at baseline, not acting ‘right’.” The patient’s level of consciousness may be impaired (lethargy, stupor, coma) and/or the patient is not acting appropriately (hyperalert/agitated, impaired cognition, confused/disoriented).


Altered mental status has literally hundreds of potential causes.  “AEIOU TIPS” is a classic mnemonic many use to systematically go through the differential diagnoses.






Opiates, Overdose








Whichever mnemonic you use, none is complete. If you want the full differential diagnostic list, Google it! Below is one conceptual tool to help you get through the first few minutes of the altered patient. The KEY to evaluating the altered mental status patient, is being meticulous in history and physical examination!



      Place patient on cardiac monitor and pulse oximetry and initiate IV access

      Obtain a stat blood glucose → administer 1 amp D50 IVP if <80mg/dL

      Obtain rectal temperature

     Hyperthermia: Aggressive core temperature lowering is emergent and should begin in the primary survey in patients with severely elevated temperatures (e.g. >104° F).  This is usually done using an evaporative technique - spraying warm water on patient and using fans) – the EP should aim to get the temperature down to 101° F in the first 30 minutes and then stop active cooling to avoid overshoot

     Hypothermia: Warming measures should likewise be initiated immediately in the hypothermic patient – the aggressiveness of these measures are dictated by the degree of hypothermia and the patient’s cardiovascular stability, with invasive measures reserved for unstable and severely hypothermic patients




      Maintain C-spine precautions if history unknown

      If apneic initiate bagging but → In the absence of other indications, hold intubation until hypoglycemia and narcotic overdose have been ruled out


      Administer supplemental O2 to maintain O2 saturation >90%

      Administer naloxone 0.4-10mg (0.4mg increments in non-“coding” patients) in     patients with any question of narcotic overdose 


      Address hypotension/hypoperfusion with volume resuscitation -IVF


      Neurologic exam FOCAL or NONFOCAL (start with pupils)

      Glasgow Coma Scale


Glasgow Coma Scale








Eye opening


To pain

To command







Inappropriate words

Confused speech







Withdraws to pain

Localizes pain

Follows commands



E- exposure

      Remove all clothing

      Look for occult injuries (e.g. trauma/stab wounds)





      Urine pregnancy





      Imaging: CT Head without contrast, CXR

      Blood: CBC, Chem7, Calcium, cultures (before antibiotics) if sepsis is a possibility

      Urine: Drugs of abuse screen, cultures



 We go though AEIOU TIPS and uncover reversible causes along the way:

“A”Alcohol/ACIDOSIS - Withdrawal/Overdose

      HISTORY: History of substance abuse, underlying psychiatric conditions

       EXAM: Refer to toxidromes and withdrawal patterns table

       NEXT STEP: ABCs, EKG, consider co-ingestion (serum acetaminophen, serum salicylate, serum volatile alcohols, urine toxicologic screen, etc.), poison control or toxicology consultation as needed, antidotes if indicated; evaluate for psychiatric involuntary hold and underlying psychiatric disease. Rx: Aggressive pharmacologic control of psychotic and hyperactive symptoms. Airway management. Supplemental vitamins, magnesium. Administer thiamine 100mg IVP if any question of nutritional deficiency (e.g. cancer, EtOH)  

“E” Endocrine/Epilepsy/Electrolyte/Encephalopathy

GLUCOSE goes here but the other E’s are actually quite uncommon and tricky so we will deal with them later 

DM (Glucose)

Hyperglycemia (Diabetic Ketoacidosis and Hyperglycemic Hyperosmotic Syndrome)

      HISTORY: History of diabetes; nausea/vomiting

      EXAM: Neurologic deficit (stroke mimic), dehydration

      NEXT STEP: ABCs, bedside glucose check, blood gas (evaluate for diabetic ketoacidosis), IV fluid resuscitation, insulin; evaluate for inciting event (medication noncompliance, infection, ischemia, point-of-care pregnancy test) 


“I” INFECTION: Severe sepsis//MeningoEncephalitis

      HISTORY: History of immunocompromised status (HIV, chemotherapy, diabetes, etc.), symptoms/signs suggestive of infection

      EXAM: SIRS criteria, decreased capillary refill, cool skin, oliguria/anuria.

      NEXT STEP: ABCs, sepsis protocol (empiric antibiotics, fluid resuscitation, possible vasopressor/corticosteroid administration, search for underlying cause).

       Pathophysiology is multifactorial and unclear, but treatment consists of controlling the underlying infection

     Administer dexamethasone (10 mg IVPB) prior to antibiotics in suspected meningitis.  Give empiric antibiotics (e.g. ceftriaxone 2g IVPB +/- vancomycin 1g IVPB).  Perform non-contrast CT Head

     Perform LP (if no mass effect or hydrocephalus on CT) and send for cell count, protein, glucose, bacterial, viral and fungal studies. Save a tube!

     If LP is positive, ampicillin may also be necessary to cover Listeria

     If LP is positive for cells but Gram stain is negative, empiric antivirals (e.g. acyclovir 10mg/kg IVPB) may be indicated 

“O” Opiates/ overdose ***critical reversible

      HISTORY: History of IV drug use or polysubstance abuse, lethargy, stupor, coma, seizure

      EXAM: Hypotension, bradycardia, respiratory depression/apnea, miosis, hypothermia

       NEXT STEP: ABCs, naloxone, IV fluids for hypotension, consider co-ingestions/drug use (e.g. acetaminophen levels for prescription oral opioids overdose, as opioids often combined with acetaminophen) 

“U” Uremic encephalopathy

       HISTORY: History of renal insufficiency or end stage renal disease

      Missed dialysis, increase in BUN/Creatinine, asterixis

       EXAM: AV fistula, dialysis catheter, oliguria/anuria; neurologic deficit, asterixis

       NEXT STEP: ABCs, EKG (hyperkalemia and dysrhythmia), serum electrolytes, emergent renal consultation for hemodialysis. Rx: Dialysis.  May need prolonged or repeated dialysis – special attention to protocol required (by renal consult! 

“T” TRAUMA: Assume trauma until proven otherwise


 INSULIN = Hypoglycemia ***critical reversible

      HISTORY: History of diabetes, comorbidities (sepsis, dehydration, malnutrition, liver/renal disease, polysubstance abuse), infant/elderly population; any focal or general neurologic change; seizure

      EXAM: Serum glucose <70mg/dL (3.9mmol/L), focal neurologic deficit (neuroglycopenia = stroke mimic), diaphoresis, tachycardia

      NEXT STEP: ABCs, dextrose IV/PO; search for underlying cause; consider glucagon IM if IV access delayed; consider IV octreotide in oral sulfonylureas



CNS: Ischemic and hemorrhagic

      HISTORY: Majority of stroke patients do not have consciousness affected; however, specific stroke syndrome as well as increased intracranial pressure (secondary to large infarcts with edema, hemorrhage, herniation, vertebrobasilar stroke, bihemispheric involvement) may lead to altered levels of consciousness; headache and vomiting are more likely to be hemorrhagic rather than ischemic/embolic

      EXAM: Focal neurologic deficit especially those following vascular territories, cardiac murmurs, irregular cardiac rhythm

      NEXT STEP: ABCs, stroke protocol (CT head noncontrast, serum glucose, EKG, reverse coagulopathies, neurology/neurosurgery consultation, etc.)

Cardiac: ACS and arrhythmia ***critical reversible

      HISTORY: Syncope, chest pain, unconsciousness, sob

      EXAM: Unstable VS, poor perfusion

      NEXT STEP: EKG, cardiac monitor

Pulmonary: Hypoxia or hypercarbia ***critical reversible

      HISTORY: History suggestive of inadequate oxygenation/ventilation, such as history of pulmonary disease (asthma, COPD, interstitial disease, pneumonia), anemia, carbon monoxide/cyanide poisoning.

      EXAM: Respiratory distress/failure, abnormal breath sounds, signs of cyanosis or clubbing.

      NEXT STEP: ABCs, oxygenation and ventilation (from supplementary oxygen to noninvasive positive pressure airway to intubation); search for underlying cause 

“P” Poisoning

      HISTORY: EtOH is most common, millions of other possibilities, check clothing, collateral history for medics, family, pharmacy

      EXAM: Toxicologic physical examination (pupils, skin (dry/wet), bowel sounds, bladder fullness)

      NEXT STEP: ABCs, supportive care, toxin specific antidotes

“P” Psychosis

Dx of LAST resort!

“S” Stroke/Seizure (Status Epilepticus)

      HISTORY: Risk factors

      EXAM: Complete neurological examination

      NEXT STEP: ABCs, supportive care

      Remember: Strokes don’t all show up on CT initially. Patients may show AMS in post-ictal phase after seizure. If they remain altered, must consider ongoing seizure (subtle status epilepticus without obvious convulsions)

David G., M.D. -

Wow, please drop the little skit that is supposed to bring us into the real-life situation. It sounded like an episode of the Powerpuff girls. "Timmy?" Really? And the humor of the "attending" physician was terrible--"get this man a cigar," and "let's get this woman's head some sieverts" (I paraphrase, as I can't bare to listen to it again.) Additionally her medicine was questionable. "Prepare to intubate" because the altered patient has no gag? First of all, a lot of awake normal people have no gag. Secondly, testing for a gag reflex in an altered patient could indeed cause a gag, which could cause vomiting, which could cause aspiration. Whether the patient is protecting her airway is a clinical call, not a simple bedside test.
Also, could you explain how syncope ends up on the mnemonic for altered MS?
Overall, good basic (though heavily opinion-based) discussion of the topic by Stuart and Mizhuho, but let's not dumb it down by the "real-life" theater.
Dave Glaser

Mel H. -

David thanks for the note. I wrote those scenes and of course they need work but we are trying something different. Can we create a little radio show and make it medically accurate and not lame? I reserve the right to completely fail. So I will keep experimenting for a while. Then get more user feedback and if the people hate the idea as you do, I will kill it. But I think there is something here if we can get the dialogue and tone right. It's Jimmy not Timmy he hates that! Given our current tech we might also be able to offer 2 versions of C3 - standard no BS, just Swad, Miz and emphasis and the ever evolving Radio Show version, users could easily choose which version they get. Mel

Tahsin K. -

I'd personally also prefer the standard version without the skits.

Charles W. -

I for one found the interaction between the attending and resident to be helpful, as well as funny. I'm not sure why Dr Glaser above was so irked by it. I actually thought the line about sieverts to the brain was hilarious! Anyways, just my two cents. Humour is an amazing way to promote retention. Keep up the good work!

Charles W. -

If I could just ask while I'm here commenting - can you compile all the C3 episodes onto a page that we can easily access? or allow us to download them individually on the app? I know they are individual units on the app now, but the old ones from episodes 120-ish are still within the whole episode so our little iphones get full too quickly trying to download them all. Thanks again.

Janelle V., PA-C -

Yes, please! I agree this would be helpful - I'm a new PA, and having easy access to all C3 episodes in one place would make it so much easier to review the basics.

Janelle V., PA-C -

Actually, I can't even find this episode on my iPhone app.

Dallas Holladay, DO -

I quite enjoyed this segment! I love the C3 concept, thank you so much guys!

Joris T. -

The C3 concept is great, it was exactly the part that I missed in the standard EM-RAP podcast. Great for bringing it to us! Personally I quite enjoyed the show with its jokes and 'theater': It keeps me focused when the really important stuff is told :). So thanks and keep up the good work!

Mel H. -

I like the idea of curating the new (and old) C3's into a more easily found place. I will work with our tech team and maybe create a place called

Miguel A. -

This would be awesome!

William F., DO -

I love the C3. Can you guys stop pronouncing mnemonic as "pneumonic"? it"s as noticeable as reality show contestants who say "surreal" when they mean, "unreal". I've had to miss out on the most important and culturally relevant events in my lifetime because of that. Don't make me have to miss out on this, too. (The 2nd most important and culturally relevant event in my lifetime). Otherwise, love this. In fact, on second thought, me skipping reality shows for the whole "surreal" thing leaves this, now, as the most important thing, in my life. I have literally nothing else going on in my life, as much as that would probably surprise you.

Steve P -

Yes, thank you! EVERYONE wants to put a U in mnemonic! While I've noticed that people of higher intelligence tend to mispronounce and misspell more often, and recognize that my own attention to grammar is likely a sign of my inferior intellect, I can't stand it when doctors pronounce things incorrectly. The case can be made that it doesn't matter as long as you make the diagnosis and heal the patient. BUT I say if we're the only keepers of this medical lexicon, then we darn well better get it right or we should just scrap it all together. The singular of nares IS NOT NARE!!! (naris)

Lennard O. -

I love the concept of the C3. As a med student I can only say: This is the kind of lecture I always hoped to hear at my university, symptom/syndrome based learning is what medical education needs. Plus I really enjoy the somewhat goofy radio show style, but I'm a fan of the Mel Herbert/EmRap humour anyways.

Charles A. P.,M.D. -

This is great! I really enjoy all the C3 talks and the added interaction between resident and attending created a more engaging atmosphere. Thank you for creating this.

Jesse H. -

Innovative! Great way to bring life to the often dry material. I will stay tuned.

Chuck S., M.D. -

Was a little unnerved that you were teaching "check the gag reflex" for a couple of reasons: 1. really bad idea in someone with a potential belly full of beer and pizza as can make the airway very difficult and 2. there appears to be no good correlation between presence of absence of a gag reflex and airway protective reflexes. Swallowing of secretions is a much better measure.
Otherwise love these (and EMRAP

Marie-Claude C. -

Really good review ! Really funny, really helpful for a young family doctor like me. Hope to access all the C3's episodes. Thank you very much for your good work.

Isaac G. -

I really enjoyed this C3 episode. Please keep this format.

Bishan R., Dr -

I really enjoyed the C3 episode. Speaking as an resident in Australia studying for his boards - this format is both informative, entertaining and memorable (the latter being something that greatly augments my study). Using the format of the Attending and Intern is really good (I quite like the jokes - they are a bit larger than life, ZDogg style - but its more like a parody of reality - nice to have some theatre mixed up in there. Thanks - keep up the good work!

Laurie NP -

As a new ED NP, I love the C3 episodes. Actually, I find all of the EMRap material to be very valuable, especially Grand Rounds!

jkolb -

Being an old guy I find it interesting how old things that were thought to be resolved start showing up again. I generally avoid any comments on anything but in this C3 repeated mention of using the "gag" reflex as useful in the intubation decision made me cringe. The absence of presence of a gag reflex seems like a horrible way to decide need for intubation. Its presence or absence tells you very little about the ability to protect the airway and could on rare occasion induce vomiting followed by aspiration. Please see letter the editor Annals Emerg Med October 1995 Volume 26, issue 4 - No gag rule for intubation.

Tanel Lepik -

I wake up at 5am. My route to work takes about 2h30min. Things to keep me awake are coffee and this new format of C3. Funny, informative and entertaining. Please keep this format.

Aaron I. -

Love the C3 concept and format. The skits make it fun and keep things interesting.

Nazanin B. -

Great work. Thnx.
Is it possible to download the Summary for each episode as PDF format? Having a quick link or printable version really helps.

Mel H. -

Go to the downloads TAB and the PDF summaries are there...

Ian L., Dr -

A lot to remember .Like a Dictionary of mnemonics and a Google Mneunics app .
E -Fast US Role re HIMAP as an additive .?

Ian L., Dr -

Too much to remember for the time .
GO2 : Glucose Opiates Oxygen .

Asad T. -

I'm a big fan of the C3 setup. Excellent for me as a medical student transitioning into medicine. Thanks Dr. Mel and staff

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C3 - Altered Mental Status - Part 1 Full episode audio for MD edition 43:35 min - 21 MB - M4AC3 - Altered Mental Status - Part 1 MP3 60 MB - MP3C3 - Altered Mental Status - Part 1 - Summary 258 KB - PDF