February 28, 2015

The Most Important Question

Yesterday I ran on a 55-year-old male with non-specific chest pain.  His presentation wasn’t screaming “cardiac” chest pain, but rather just kind of vague, could-be-anything package of generalized malaise and precordial discomfort.  There was no recent trauma, his ECG was completely unremarkable, and his exam was generally unremarkable.

When I am on a call, I get to a point where I have a pretty good idea of what is going on.  I have the OPQRST story, SAMPLE history, or whatever mnemonic you happen to use.  A set of vital signs are taken, and any other evaluation adjuncts like 12-leads and blood sugar levels are done.  After about five questions, or so, a medic has enough of an idea of what is going on to piece together a one-sentence description of what is going on: “Fifty-five male, non-specific chest pain.”  At this point, I need to think of differentials.

Differential diagnoses answer the question, “What is going on with this patient?  What else could it be?”  So for atraumatic adult chest pain, a minimal differential list would include things like:
  • Acute myocardial infarction
  • Pericarditis/Myocarditis/Endocarditis
  • Stable/Unstable/Prinzmetal’s angina
  • Pulmonary embolism
  • Pleural effusion
  • Pleuritis
  • Acute aortic syndromes such as thoracic aneurysm or dissection
  • Costochronditis
  • Intercostal muscle strain
  • Occult trauma (don’t forget this one, even on atraumatic lists)
  • Pneumothorax
  • Pneumonia
  • Hyperventilation
  • Thoracic disk herniation
  • Coughing-related stress fractures
  • Rib fractures related to neoplasms
  • Arrhythmogenic pain (such as from tachyarrhythmias)
  • Aortic stenosis
  • Reflux esophagitis
  • GERD
  • Malingering (this one should always be last of all)
  • And many more.  But this is a decent start, for now.

As I am working through the call, I think of these diagnoses, consider specific presentations or information that would rule in or rule out each diagnosis, and continue to work through the call.  For example, when considering pulmonary embolism, I would ask about the nature of the pain, consider the patient’s respiratory rate and heart rate, ask about birth control (not in this patient, but you know what I mean), ask about immobility or travel, and so on.  Eventually I get to the point that I find PE to be unlikely and mark it off my list, or find that I can’t rule it out.  In the latter case, I need to treat for that condition. 
Pneumothorax is on the causes of chest pain list. (This one is on the left - viewer's right.)  Listen to breath sounds.
(By Hellerhoff (CC BY-SA 3.0) via Wikimedia Commons)
With this patient, as the call went on, I asked myself, “Self, what else could it be?”  Occult trauma came up on the list.  I asked the patient if he had experienced any “…accidents, falls, car crashes, bar fights, shark attacks, or that kind of thing…” recently.  He chuckled and denied.  I lifted his shirt and checked his chest and back.  Atraumatic.  I can essentially put a line through occult trauma on my mental list and ask the question again: “What else could be going on?”

I worked my way through the list to pericarditis.  Without asking the patient, I attempted to ease him back from a sitting position on my bed to a supine position.  The patient commenced to bitching about how that made him worse.  I asked him about recent medical or dental procedures, and he told me about having extensive oral surgery performed about a week prior.  Well, now.  It seems as though pericarditis is still a contender, huh?  Pericarditis is still on my list.  But here is the important thing – as I start treating the potential pericarditis (IV access, analgesia, and so on), I ask myself the important question: “What else could it be?”

I use the patient’s presentation to decide how I work through the list.  If I am caring for a patient who looks sick or toxic (pale, cool, diaphoretic, altered, hypotensive, and so on), I would start at the most dangerous items on my list.  My personal “most dangerous” chest pain cause list includes AMI, PE, the aortic problems, and pneumothorax.  If a patient looks just fine, with normal vitals and an unconcerned affect, I would instead begin with the more common diagnoses. 

Apparently, some medics don’t practice prehospital medicine in this manner.  They are more comfortable working off of a complaint-based list.  A “chest pain” patient causes them to mentally turn to the chest pain checklist: vitals, O2, 12-lead, IV access, aspirin, and transport.  Abdominal pain results in the abdominal pain checklist: vitals, O2, 12-lead, IV access, and transport.  In my humble opinion, this is a poor way to provide care.

Continually ask yourself the important question: “What else could it be?”  Work through another differential on your list.  Keep ruling out or ruling in items on the differential diagnosis list.

It is interesting, by the way, that trauma care is similar but with a different question that changes the mental orientation toward the call.  Stay tuned for the difference, coming next week.

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