Listen for ALL of the Hoof Beats – Aphorisms and Diagnoses in EMS

An aphorism is defined as an original thought, spoken or written in a concise and memorable form. The term can be defined literally as a simple distinction or the very definition of a thought that gets at the base of a concept. Think of phrases like “Brevity is the Soul of Wit” or “Never get into a battle of wits with a Sicilian when death is on the line.” Medicine has a unique relationship with aphorisms as the term itself was first used as the title of the manuscript the Aphorisms of Hippocrates, the author of which you may know from a certain oath that new doctors have to take.

One of my favorite aphorisms is credited to Dr. Theodore Woodward as coined in the 1940s. He gave an order to his interns intended to guide them in making diagnoses. He said “When you hear hoof beats, think horses not zebras.” It works well if you don’t live in an area where zebras are very common. I try to keep it in mind when I’m diagnosing patients because rarely do my unresponsive patients have African sleeping sickness. Most of the time they’re just hypoglycemic.

But what if they aren’t?

The call:

It was a beautiful day for a ride. Not-too-hot and not-too-cold, the sun was shining, and the only clouds in the sky were the friendly kind that might have smiles drawn on them if they were in a cartoon. It was the perfect day to take a new Harley Davidson out for a spin. Well it would be, except for the fact that the guy who did crashed into a parked car while pulling out of his driveway.

“Medic 84 respond to 435 Ashton Street, 435 Ashton Street for the motorcycle accident. Police on scene requesting an ambulance for a leg injury. Charlie-level response. Time out 13:15”

It was a short drive from the station to the residential neighborhood where the call came in and you arrive within a few minutes. You tell dispatch that you’re on scene and park in front of the patient and the squad car that is blocking traffic. There are a few bystanders and a cop assisting a gentleman who is sitting on the ground between a beautiful piece of shiny chrome testosterone and his neighbor’s unfortunate Ford. Just by walking up to the patient you can see that his ankle isn’t quite in anatomical position. Even through his jeans it’s painful to look at. His neighbor stands up to talk to you while your partner kneels down to assess the patient.

“I heard the crash and came out here. He wasn’t making any sense at first and I had to keep his head up so he would stay awake. He kept trying to pass out on me. I was supposed to keep his neck straight and I did. His ankle’s broken. Did I do ok?”

You thank her for her assistance and assure her that she did just great. She did, really. In fact she’s definitely in the running for the Most Helpful Bystander of the Shift Award. She didn’t even seem to be mad about the dents on her car. I’d christen her as a “nice lady.”

You hear your partner asking questions to the patient about the accident. Nobody actually saw it happen but the patient is awake and alert. He says that he crashed because of his “stupid driveway” that he hates and was always going to fix. He’s in his 60s and has lived at this address for 30 years but he’ll probably get around to fixing it soon. However, the driveway looks fine to you. In fact, you can’t really see a reason for this crash to have happened. The patient talks like an experienced motorcycle rider and certainly looks the part. You’d never guess that he was in his 60s if he hadn’t told you. He certainly seems healthy and has no medical history. He takes no medications and has no allergies. His daughter confirms this when she pulls up on scene. One of the neighbors called her before you arrived.

Your partner asks you for an ankle splint and you retrieve it from the truck. When you get back with it you hand your partner your trauma shears so he can cut the patient’s jeans. While he does, you take a look at the patient. He’s paler than you think he should be. When you touch his forehead it’s ice cold and you can’t find a radial pulse when you feel for one. Subtly you let your partner know of these things but he’s not so concerned. Together you splint the leg. The patient meets your criteria for selective spinal immobilization with no pain in his head, neck, or back, no obvious impairment from drugs and/or alcohol, full consciousness and alertness to his surroundings, no neurological deficit, no pain to palpation along his spinal column, and no pain to movement. His trauma assessment is unremarkable other than for the obviously fractured Tib/Fib which he is tolerating well. After the patient’s leg is properly splinted, you move him onto the cot, secure him, and take him into the truck.

Sounds like a simple leg fracture, right? A quick trip to the community hospital ED is in order so they can call Ortho on the guy to get that tib/fib taken care of. Simple, quick, and easy… except for the fact that maybe it isn’t. Luckily your partner is of the same mindset that you are and always performs a detailed assessment on each and every patient. Here’s what he finds:

  • Skin: Pale, Cool, and diaphoretic not matching the ambient environmental conditions.
  • Pupils: PERRL
  • Lung sounds: Clear bilaterally with equal chest movement
  • Abdomen: Soft and non-tender with no appreciable masses nor pulsation.
  • Musculoskeletal: All extremities intact with good distal pulses, motor function, and sensation except for the Right lower extremity which has the aforementioned displaced fracture.

Further questioning of the patient reveals that the cause of the crash was “that stupid driveway” but there seems to be more. It’s like pulling teeth, but you learn that the patient has been feeling poorly today and has been suffering from increased fatigue, exertional dyspnea, and… chest pains for the last day or so. A 12-lead EKG reveals this:

Courtesy of


Uh huh. Is this a Zebra? Probably not as people in this patient’s age bracket have heart attacks all the time. They also have syncopal episodes that accompany their heart attacks when their blood pressure drops. This guy just tried to mask his STEMI by presenting as a trauma patient. I’d consider this as being two horses sounding hoof beats using Dr. John Hickam’s dictum (which is an answer to Occam’s razor). It states that “Patients can have as many diseases as they damn well please.”

We may not find many Zebras out there in the field, but horses are known to travel in groups. A thorough assessment is warranted on everyone, no matter how obvious their diagnosis may seem. Taking this patient to a community hospital to fix his leg would have delayed the treatment for the STEMI that caused it. Keep Leonard’s Law of Physical Findings, which states “It’s obvious or it’s not there” in mind but be mindful to look for all of the available physical findings. Do thorough assessments on everyone. You’ve got to hear all of the hoof beats if you want to catch all of the horses. Who knows? Someday you might even catch that occasional Zebra.

  • Giuseppe Diele


  • totwtytr

    I don’t see a zebra here, really. Reading through your post, I see a 60 year old male who had a syncopal episode that caused his MVA. I don’t know of any EMT or paramedic who wouldn’t be concerned by a lack of a radial pulse, pallor, and diaphoresis. That would lead me at least to dig a bit deeper and check things that I might not normally lock at in a trauma patient.

    It’s not tremendously uncommon for a medical event to cause trauma. When the medical condition is out of proportion to the potential mechanism, then a deeper look is in order.