In previous posts, I wrote about paramedics’ ability to identify STEMIs and about the computer’s ability to identify STEMIs. My conclusions were that unless 12-lead interpretation is a major and continual focus of paramedic education and qualify assurance, paramedics’ ability to recognize STEMI will not be optimal. While most paramedics can easily identify an inferior STEMI, lateral and anterior can at times be more difficult, the lateral because it is often subtler and the anterior because it is often confused by the STEMI mimics. As far as the computer’s interpretation ability, while it can be used as an interpretation assist, and is constantly being improved, I don’t feel it is yet ready for prime-time. The software misses too many STEMIs and inaccurately calls too many nonSTEMIs as STEMIs. While the computer companies are working hard to improve their algorithm, they are just not there yet. Today I address the question of transmitting 12-leads. Should all paramedic services be required to have 12-lead transmission capability?
I admit I have had a small bias against transmission. The services I have worked for have not had the transmission capability (We are getting it very soon). In our area there are three hospitals that allow paramedics to activate the cath lab based on recognition, one that requires transmission for the hospital to preactivate the cath lab. Unless, the patient absolutely insists, I go to the other hospitals because I know I can get the patient to the cath lab quicker because those hospitals will activate in advance of our arrival at the ED based on my interpretation alone. I do also work for a hospital where half the STEMIs that come in are from services that transmit and the other half do not. Our best times are from the service that does not transmit, but just barely.
Transmission is not necessary for the obvious big I can see it from across the room STEMIs if you have a paramedic who can give a good patch and a doctor at the other end willing to trust the interpretation. Two hospitals in our state that have excellent door to balloon times (their medics go right to the cath lab) do not rely on transmission at all. But here is the question I wonder about. If you rely on paramedics alone, are paramedics more apt to only call in the obvious STEMIs? What happens to the patients with the more subtler STEMIs? Are they missed? I would like to see a study asking this question. I wonder about this because we have had an occasional hard time just getting paramedics to call in on obvious STEMIs. In hospitals that have 100% of their services transmitting, do they have fewer missed STEMIs than those hospitals where none of their services transmit? By missed STEMI I mean a STEMI that is not recognized until the hospital that shows the same morphology on the prehospital 12-lead as opposed to the ECG evolving into a STEMI after ED arrival. My guess is that the all transmission system, where paramedics are encouraged to send in borderline 12-Leads capture a greater percentage of STEMIs. But this is just a hypothesis. I await a study for verification.
What do I feel is the ideal system? Here it is:
1. Include 12-lead competency in all paramedic education and QA
2. Encourage medics to consider but not rely on computer interpretation.
3. Tell medics to call in not just definite STEMIs but possible STEMIs. There is no shame in being wrong.
4. Add transmission capability.
With these four components in place, no STEMI should fall through the cracks.