Can Paramedics Effectively Identify STEMIs on Prehospital ECGs? - @

Can Paramedics Effectively Identify STEMIs on Prehospital ECGs?



Keith Wesley, MD, FACEP | | Thursday, May 14, 2009

Review of:Trivedi K, Schuur JD, Cone DC: "Can paramedics read ST-segment elevation myocardial infarction on prehospital 12-lead electrocardiograms?" Prehospital Emergency Care. 13(2):207-214, 2009.

The Science

This study used a convenience sample survey of paramedics from a large career system. The authors provided the medics with scenarios of men and women with and without cardiac risk factors, as well as ECGs with and without ST elevation. All ECGs were computer generated. At the time of the study, the system had not implemented a cath lab alert program but did allow medics to "alert" the hospital of a possible ST-segment elevation myocardial infarction (STEMI), and the emergency department (ED) would wait until after patient arrival to activate the cath lab.

The authors surveyed 70% of their medics who had an average of 8.7 years of experience and estimated that it took the medics three minutes to obtain a 12-lead ECG. The medics reported their confidence in interpreting a 12-lead for STEMI at 3.7 on the 5-point Likert scale. Similarly, they reported a 4.0 of placing the ED on "chest pain alert" and 3.7 for "activating the cath lab."

Upon review of their ECG interpretation, the authors determined that the paramedics accurately detected the presence of a STEMI 85% of the time (specificity). Of the STEMI cases, 94% resulted in a simulated cath lab activation. Of the non-STEMI cases, 14.9% resulted in simulated cath lab activation.

The authors concluded their paramedics could accurately interpret prehospital 12-lead ECGs.

The Street

Although I agree with the premise of this paper, I disagree with the title and basic conclusion. A more accurate title would be: "Can paramedics detect signs of STEMI in standardized computer generated 12-lead ECGs in a scenario-based setting?"

The differences are significant. Can paramedics interpret 12-lead ECGs? Certainly. So can EMT-Bs, if provided sufficient education. That's why we have textbooks and conferences. The question is whether medics make the call in the field when the patients present with vague symptoms and ECGs that are less dramatic. The ECGs used in this study had more than 4 mm of ST elevation. It would be hard to miss this.

The next obstacle is activating the cath lab. In some systems, the criteria is 1 mm of ST elevation in the inferior leads and 2 mm in the precordial leads. In other systems, the threshold is only 1 mm of ST elevation in the precordial leads. In many systems, the medic must rely on machine interpretation, confirm that interpretation and communicate that to the receiving hospital to activate the cath lab.

In all fairness, the authors recognize the primary limitation of the study is that it was scenario-based. They have moved forward to examine the accuracy of the medics under a clinical perspective.

The issue of over- and under-triage is important. Although I applaud the authors on achieving an 8% over-triage based on this scenario-based study, the reality is that this comes at the cost of a significant under-triage of 9% of very obvious STEMI cases. I would speculate that this will result in an even greater percentage in actual practice unless the authors consider using a combination of computer interpretation and on-line medical control consultation.

Under-triaged patients are missed opportunities to save time and myocardium.

Connect: Have a thought or feedback about this? Add your comment now
Related Topics: Cardiac and Circulation, Research, Training

What's Your Take? Comment Now ...

Buyer's Guide Featured Companies

Featured Careers & Jobs in EMS

Get JEMS in Your Inbox


Fire EMS Blogs

Blogger Browser

Today's Featured Posts


EMS Airway Clinic

Innovation & Advancement

This is the seventh year of the EMS 10 Innovators in EMS program, jointly sponsored by Physio-Control and JEMS.
More >

Multimedia Thumb

Salt Lake City Firefighters Injured in Firehouse Fire

Nine sent to a hospital with smoke inhalation.
Watch It >

Multimedia Thumb

Pennsylvania Paramedic Killed in the Line of Duty

West End Ambulance medic killed at accident scene.
Watch It >

Multimedia Thumb

Wesleyan Students Hospitalized for Overdose

11 students transported to local hospitals.
Watch It >

Multimedia Thumb

Rigs Going in Service from EMS Today 2015

Snap shots of some of the vehicles at EMS Today that will be on the streets soon
More >

Multimedia Thumb

Florida Hospital Fire

Fire halts construction project at Tampa cancer center.
More >

Multimedia Thumb

The AmbuBus®, Bus Stretcher Conversion Kit - EMS Today 2013

AmbuBus®, Bus Stretcher all-hazards preparedness & response tool
Watch It >

Multimedia Thumb

VividTrac offered by Vivid Medical - EMS Today 2013

VividTrac, affordable high performance video intubation device.
Watch It >

Multimedia Thumb

Braun Ambulances' EZ Door Forward

Helps to create a safer ambulance module.
Watch It >

Multimedia Thumb

LMA MAD Nasal™

Needle-free intranasal drug delivery.
Watch It >

More Product Videos >