“What’s that?” asks a student on another ambulance, pointing to my cardiac monitor.
“It is the plethysmograph” I replied, most likely butchering the pronunciation.
“What’s it for?”
After dropping my patient off, I made my way back to the EMS room where I found the student. It turned out he is a paramedic student, just finishing up his intern rides. He has a few weeks to go before he takes his exam. He has been an EMT for roughly 4 years, and by all accounts, is a good student, and a fast learner.
The fact that he asked a paramedic whom he didn’t know bodes well for him. He is engaged, and wants to learn.
We spent the next 15 minutes or so discussing the plethysmograph and its usefulness in assessing patients. What struck me most about our conversation was the fact that he had no idea whatsoever that there was even such a thing, much less that it could be used to assess patients.
We talked about how vasoconstriction can cause an increase in amplitude, and what could cause vasoconstriction. We talked about how vasodilation would cause a decrease in amplitude, and the causes of vasodilation.
We discussed how waveforms would change in a hypertensive patient with chest pain to whom we were administering nitroglycerin. The mechanism of nitro’s action, in decreasing systemic vascular resistance through causing vasodilation. It seemed to make sense how waveforms would change, and how that was directly related to afterload.
My patient happened to be septic, and I could show him how plethysmography could help confirm that diagnosis. My patient was an infirm older woman who had a mildly altered mental status, hypotension, and some mild tachycardia. The fact that she had a chronic Foley catheter with cloudy urine in the bag made the diagnosis of a UTI fairly easy, but the plethysmograph showed a very deep, prominent dicrotic notch.
He asked, appropriately, how the waveform would help me in my assessment, and I explained that the deep dicrotic notch showed me a low SVR, and there was no need to assess orthostatic vital signs.
He was receptive, inquisitive, and it was a refreshing conversation.
I’m just a regular paramedic, and nothing special. I only learned about this stuff because I asked and because I wanted to learn. I enjoy showing students, and other EMS personnel, things that I have learned along the way, and I enjoy learning from others. Our education doesn’t stop when we get that paramedic patch, it begins.
What is disheartening is the fact that a paramedic student, only weeks away from testing to become a paramedic, had never heard of a plethysmograph, a dicrotic notch, and did not understand the relationship between waveforms and vascular resistance.
We have a very, very long way to go in the education of our paramedic students.