Transcutaneous Pacing Success!!! Part 2

This is the second half of a two-part case presentation examining transcutaneous pacing. If you didn’t see yesterday’s post I highly suggest checking out Part 1 before continuing, but if you hate learning I suppose you can start here.

Yesterday we examined a series of tracings that depicted transcutaneous pacing (TCP) in all its stages: initiation, false-capture, intermittent capture, successful capture, and finally, spontaneous resolution of the bradycardia that necessitated pacing in the first place. It was a whirlwind!

Intermittent capture

Intermittent capture with the Lifepak 12 set at 150 mA and 80 bpm.

As we mentioned in that post, however, there was a catch: We only discussed success in terms of electrical capture. What about mechanical capture? What good is it to achieve good electrical capture if we can’t confirm that the patient’s cardiac output has actually increased?

That is today’s topic.

 

Pad Placement

Before we actually get into the topic at hand I need to touch on something that has come up several times recently. Maybe it’s just a coincidence, but of late I’ve seen several crews that I work alongside bring in patients with anterior-posterior pad placement—my preferred setup for either pacing or defibrillation—however some wires must have gotten crossed in training because the pads are set up like the patient is 7 years old.

Image source.

Image source.

As the image above demonstrates, sternal-spinal pad placement is only recommended for pediatrics. Proper anterior-posterior placement on adults (for pacing and defibrillation at least) requires that the pads be placed to the left of the spine and sternum.

Recall that the goal with A-P positioning is to sandwich the heart between the pads so:

  1. There should be as little thoracic impedance between the pads as possible.
  2. The current delivered is angled directly through the bulk of the ventricular myocardium.

By optimizing those two factors we hope to obtain ventricular capture at as low a current as possible—increasing the chance of success, giving us more room to escalate the “dose” as needed, and (I list this third because it is least important in the emergency setting) decreasing the amount of energy being delivered to the heart and chest.

Incorrect AP Pad Placement

Transverse - Incorrect (sternal-spinal) pad placement. Note that the current intersects part of the right ventricle and the left atrium—not the bulk of the myocardium like we would prefer.

Since surface anatomy can vary wildly from patient-to-patient I won’t set any hard rules about where the pads go—just try to sandwich as much as the ventricles as efficiently as possible—but keep the diagrams below in mind.

Correct AP Pad Placement

Transverse - Correct pad placement. Note how the current travels mostly through the left ventricle, attempting to engage as much myocardium as possible.

Correct AP Pad Placement

Sagittal – Ideal pad placement. Depending on patient anatomy this positioning may not be possible.

Alternate AP Pad Placement

Sagittal – Alternate pad positioning that may be required depending on patient anatomy. Note that not only is the anterior pad shifted caudal, the posterior pad is shifted cephalad to compensate and ensure the pacer current travels through the center of the heart.

 

Pulse Palpation

Okay, so we’re back on topic and discussing how to confirm mechanical capture. First up is manual pulse palpation.

This is the method all the textbooks and ACLS classes teach. First you confirm electrical capture (something that is already poorly taught and fraught with pitfalls), then you palpate a radial, femoral, or carotid artery to feel for an associated pulse. It’s so simple.

Except that it’s not.

I’ve stopped counting the number of times that I’ve seen providers of all levels and experience attest that they felt a good pulse with pacing only to see the tell-tale signs of false capture on the corresponding rhythm strips.

You cannot have mechanical capture without electrical capture. Now there’s a truly simple concept.

In real-time I can demonstrate, objectively, why a patient actually does not have capture, but time-and-again experienced providers will still argue that they feel a good pulse and shut out any suggestions to the contrary. The problem is that most of their clinical senses are telling them there should be capture. They see a monitor showing large blips that look like QRS complexes. Their fingers feel movement corresponding to each discharge of the pacer. Their assessment observes a patient who is more awake and responsive, maybe with a non-invasive blood pressure that is trending upward. Sometimes they even hear the monitor beeping in-time with the pacer spikes.

They have every reason to think that the transcutaneous pacer is capturing… And they really want it to. Heck, I want there to be capture too, I’ve just been fortunate to have had some good teachers who taught me about the pitfalls associated with TCP early in my career.

I once encountered a case where an entire team of experienced, expert emergency clinicians at a regional trauma and cardiac center were absolutely convinced a patient captured at only 10 mA with TCP. I’m going to venture a guess that no adult (or even child) on Earth has ever captured with only 10 mA of current during transcutaneous pacing—yet these otherwise excellent clinicians wanted to believe in their success so strongly that they totally missed the objective signs that they were dealing with false capture. I’m sure multiple people in the resus bay felt for a pulse, yet no-one involved in the case realized that there were other, more trustworthy signs that the pacer was not capturing.

I’m not saying that pulse palpation is useless in the emergency setting—just that it is an inferior tool in our bag and should be discarded in favor of much more objective and reliable measures when they are available. And when you are forced to rely on a manual pulse to confirm mechanical capture, approach the situation with a mindset of skepticism; looking for any indications that what you think you are feeling may not be a true pulse.

That said, there should be very few situations where you need to rely on pulse palpation because most emergency care providers already have the real tool they need to confirm capture readily available.

 

Pulse Oximetry

In the preshospital setting this is my preferred method of confirming mechanical capture. Why trust your feeble human fingers to palpate a pulse when a machine can do the job better with less risk of error and no bias.

You would think that the pulse oximeter would be just as easy to fool as your fingers… but you would be wrong [most of the time]. When properly placed our often-finicky SpO2 probes actually perform quite well during TCP. Despite the apparent torso motion accompanying each pacer discharge, it’s surprisingly easy to get a clean signal unaffected by movement with the pulse-ox on a finger or toe. The latter setup is probably preferred because the feet are further from the twitching that accompanies each shock, but I’ve seen finger probes work just as well a number of times.

In fact, in every case of false-capture that I’ve encountered where the team caring for the patient obtained an SpO2 waveform, the patient’s underlying heart rate was been clearly visible on the pleth while the ECG monitor (and providers) were fooled by the pacing artifact.

Here’s an example from yesterday’s case: This is what we saw on the LP12′s rhythm monitor at the start of pacing (10 mA and 80 bpm).

Pacing spikes with no signs of electrical capture.

Pacing spikes with no signs of electrical capture. You’d better believe there are experienced clinicians who would think they felt a pulse with this.

At the same time, however, the patient was also attached to a GE DASH bedside monitor with a pulse oximetry probe on his toe. Here’s what we saw on there:

Initiating of pacing.

Initiating of pacing. The bottom line shows the pulse-ox waveform.

As you can see, though the ECG waveform is obscured by pacer artifact and could be mistaken for capture at a rate of 80 bpm, the pulse-ox waveform is totally unphased and marches right along at about 20 bpm—the patient’s intrinsic heart rate.

What happens when we observe capture?

Recall that the patient in this case achieved only partial-capture at first. In yesterday’s post on electrical capture that allowed us to directly compare the true-capture and false-capture waveforms.

Intermittent electrical capture.

Intermittent electrical capture.

We can do the same with the pulse-ox!

Intermittent capture.

Intermittent mechanical capture. Though this was captured within a minute of the LP12 strip above, they do not show the same point-in-time.

On the strip above you can clearly see the rapid deflections corresponding to the pacer spikes that have successfully captured (note also the change in QRS morphology), while there are periods of no activity on the pleth corresponding to strings of non-conducted pacer spikes.

As the current was increased further the pulse-ox waveform became more regular.

Mostly mechanical capture.

Mostly mechanical capture.

There are still occasional dropped beats—visible on both the ECG and SpO2 waveforms—but it is clear that we are now seeing excellent electrical and mechanical capture.

If there was any doubt, check out how the pulse-ox doesn’t even falter when the patient’s intrinsic heart rate increased to the point that it usurped control from the transcutaneous pacemaker. I think it’s a thing of beauty!

Sinus rhythm usurping control from the TCP.

Sinus rhythm usurping control from the TCP.

Hopefully you’re buying what I’m selling here. I’ve got maybe ten other cases showing true and false-capture clearly visible on the SpO2 waveform but we’ve got to keep moving so you’ll have to look forward to seeing some of those in another post. In summary: pulse oximetry works!

 

Waveform Capnography

I don’t have any personal experience with this modality during TCP (and didn’t use it in this case) but there are reports of folks observing an increase in cardiac output corresponding to successful mechanical capture via end-tidal waveform capnography. In fact, we’ve got one right here on this blog!

The capnographs at my facility are notoriously finicky and I personally wouldn’t be itching to use ETCO2 to confirm capture when SpO2 and the next option are so straightforward and readily available, but consider this in your own armament depending on where and how you practice. At the very least, see if you can observe an increase in cardiac output as a bump in the ETCO2 if you happen to already have the capnograph running on your patient before initiating pacing.

 

Echocardiography

This one is my absolute favorite!

Though it’s not an option for most prehospital providers, if you happen to work in an emergency department or advanced transport setting where ultrasound is readily available this is the #1 method of confirming mechanical capture during transcutaneous pacing. It’s so simple:

  1. Slap the ultrasound probe on the patient’s heart.
  2. Directly observe the patient’s heart rate increase.

It couldn’t get any easier and more foolproof—assuming you’re comfortable performing a basic cardiac exam on ultrasound.

In this case, because of how rapidly the patient deteriorated on arrival, I wasn’t able to obtain a pre-pacing clip of the heart beating 20 times a minute, but once we observed electrical capture on the rhythm monitor and mechanical capture on the SpO2 I was able to confirm that the heart was indeed contracting (quite well) at 80 bpm in response to pacing:

As you can see, the heart is contracting quite vigorously in response to TCP (sorry I couldn’t avoid the lung shadow with the patient on the vent). The practiced-eye will note an apparent dyssynchrony caused by the abnormal ventricular activation but it’s clear that the heart is generating a reasonable cardiac output. This was confirmed with both manual and automatic non-invasive blood pressures along with improvement in the patient’s clinical condition.

Success!!

For another case demonstrating the use of echocardiography to confirm mechanical capture check out this excellent case from the Ultrasound of the Week blog. Seriously, there’s some awesome clips and it’s a really short case. It’s also where I first got the idea to confirm capture with bedside USS, so show Dr. Ben Smith some love.

In summary:

  1. Check your pad placement and sandwich the heart.
  2. Don’t trust a manual pulse unless you like being wrong most of the time.
  3. Pulse oximetry rocks for confirmation of capture and is readily available.
  4. ETCO2? An interesting finding but I wouldn’t use it as the “proof” I need.
  5. Direct visualization under ultrasound is ideal, though rarely an option outside the ED.

 

Further Reading:

All our articles on transcutaneous pacing.

Transcutaneous Pacing Success!!! Part 1

Anyone trained in transcutaneous pacing (TCP) needs to be able to identify the rhythm below instantly.

False-capture with transcutaneous pacing.

Successful transcutaneous pacing?

It shows a patient being transcutaneously paced at 80 bpm and 125 mA on a LifePak 12 [the strip is labelled 130 mA but that refers to a point just past the end of the paper, I promise].

Well, actually, it shows attempted pacing. Despite the generous current being delivered there is no evidence of successful electrical capture. Without electrical capture there cannot be mechanical capture, so the patient’s pulse at the moment is actually 10 bpm.

Here are the patient’s two native QRS complexes—the only ones generating a cardiac output as a result of his exceedingly slow baseline rhythm.

Though they resemble QRS complexes, the fourteen other “blips” you see on the strip are actually just artifact from the pacer. This phenomenon is commonly referred to as “false capture” and it is a huge problem.

 

The Problem of False Capture

On November 12, 2008, Tom Bouthillet published an article on this blog that hit me as a revelation and changed the way I approach transcutaneous pacing.

Transcutaneous Pacing (TCP) – The Problem of False Capture

You need to go read his article right now. I’ll wait here.

Learn something.

Before encountering that post I had no idea how difficult it could be to achieve and identify successful transcutaneous pacing. Since then I’ve seen dozens of cases of attempted TCP—both in person and shared by colleagues and readers—but very few of them have demonstrated even intermittent capture.

The catch is that, in most of those cases, the treating providers were absolutely certain they had achieved good capture. Patients woke up; non-invasive blood pressures improves; mechanical capture was confirmed with pulse palpation—but regardless of how confident the team managing the patient was, in almost every case the rhythm strips they showed me were pathognomic of false capture.

Tom turned me into a TCP skeptic and that is in every way a good thing.

I don’t care how strong a patient’s radial pulse feels while they are being transcutaneously paced; you cannot have mechanical capture without electrical capture. And without true mechanical capture, any improvement in the patient’s condition is merely the result of noxious stimuli being provided 60–80 times a minute; often for hours on end. The patient might become more alert, but not because their heart rate has increased significantly.

Patients get admitted overnight on ineffective transcutaneous pacing.

While pacing isn’t always a terrible experience if the current is increased slowly and the patient understands what is going on, being shocked all night to zero benefit sounds like torture to me.

Again, for more information on the problem of false-capture and how to identify ineffective pacing go re-read Tom’s article, but what follows is a case that demonstrates false-capture, true-capture, and two objective ways of confirming mechanical capture.

 

The Case

The details of the case are not overly relevant, but let’s say a patient presents quite unwell with a pulse of 20 bpm. No es bueno. Here is his initial 12-lead:

A very sick heart.

Sinus rhythm w/ marked sinus arrhythmia, high-grade AV-block (fixed PR-interval), and RBBB. There is not a single measurement or computerized statement that I agree with here. Remember: the sicker your patient, the less useful the machine’s diagnosis becomes.

 

Atropine is administered and fails to improve the heart rate. Time to start transcutaneous pacing.

Complete heart block with a ventricular rate of 15 bpm.

With “demand” pacing turned on (usually the default), the machine tracks the native QRS complexes—as evidenced by the inverted triangles just above each QRS—but since it is set to 0 mA no current is delivered and there are no pacing spikes.  The rhythm here appears to be complete heart block with a ventricular rate of approximately 15 bpm.

 

The current is increased from 0 mA to 10 mA.

TCP at 10 mA with no capture.

There are prominent pacing spikes at 80 bpm with tiny blips after them that almost look like P-waves (they’re not). You can see the patient’s underlying rhythm marching through at approximately 20 bpm and being tracked by the monitor.

 

The current is increased from 10 mA to 30 mA.

TCP at 30 mA with no capture.

This strip looks very similar to the prior tracing except that the blips following the pacer spikes seem slightly deeper.

 

The current is increased from 30 mA to 50 mA.

TCP at 50 mA with no capture.

Similar to the last tracing, but the post-pacer blips are definitely deeper.

 

The current is increased from 50 mA to 70 mA.

TCP at 70 mA with no capture.

More of the same. Still no capture.

 

The current is increased from 70 mA to 90 mA.

TCP at 90 mA with no capture.

Sensing a pattern?

 

Most providers give up on transcutaneous pacing before even reaching 90 mA but, having read Tom’s article, you know that is a fallacy.

The current is increased from 90 mA to 110 mA.

TCP at 110 mA with no capture.

More of the same pattern and still no capture.

 

Keep going…

The current is increased from 110 mA to 125 mA.

TCP at 125 mA with no capture.

This is the same tracing shown at the top of this article. After deliberately walking our way up from 10 mA does it still look like there could be capture?

 

Don’t give up yet…

The current is increased from 125 mA to 130 mA.

TCP at 130 mA with intermittent capture.

Finally! A Change!

We finally see a few complexes that demonstrate true capture! Note how the capture beats are followed by wide, obvious T-waves, while the false-capture pacer artifacts are only followed by diminutive pseudo-T-waves.

 

Spurred on by signs of success, the current is increased to 135 mA.

TCP at 135 mA with mostly successful capture.

Mostly capture! There are two pacer spikes without capture but the majority of the rhythm is finally composed of complexes that show true electrical capture.

 

The patient will be leaving the emergency department to go to radiology so the current is increased from 135 mA to 145 to ensure safe capture through the trip. Just before leaving the resus bay a problem is noted though…

TCP at 145 mA with an episode of failed capture.

It looks like we’re losing capture…

What started out as a couple of dropped complexes has progressed to a string of six non-captured pacer spikes… This will not do.

Time to up the current a bit more to 150 mA.

TCP at 150 mA with mostly successful capture.

This is a bit better but there are still a couple of non-capture beats. That is, until…

TCP at 150 mA with an episode of failed capture.

Gah! Lost capture again! This patient is never going to make it to radiology.

 

The current is increased to 155 mA…

TCP at 155 mA with several episodes of failed capture.

Ugh, still no consistent capture.

 

Not one to give up, you increase the current to 165 mA. Remember: Tom taught us that the monitors go up to 200 mA for a reason—if a patient needs 200 mA to capture and stay alive then that is simply what they need. The rate is also decreased to 70 bpm (just because).

100% transcutaneously paced rhythm at 165 mA and 70 bpm.

Finally! This strip shows a 100% transcutaneously paced rhythm. Note: this is lead II.

We finally see consistent 100% capture; a pattern which continues through the patient’s trip to radiology and the the next hour.

Note that the above strip shows lead II—below are two more strips with the same 100% paced pattern but viewed through leads I and III (just to show how pacing can look different depending on the lead used).

Successful transcutaneously paced rhythm as seen in lead I. The pause at the start of the strip is suspicious for a non-conducted pacer spike but since it’s not well visualized we won’t worry about it here.

Successful transcutaneously paced rhythm as seen in lead III.

 

Below is one more perspective of successful electrical capture—this time from a GE DASH bedside monitor.

Successful capture on a GE DASH monitor. Note that at this point the setting for the rate has been decreased to 50 bpm.

Successful capture on a GE DASH monitor. Note that at this point in the resus the pacing rate has been decreased to 50 bpm.

 

An hour later, after the patient has stabilized, a change is noted on the monitor.

This strip shows sinus rhythm at 75 bpm with a first-degree AV-block. There are no paced complexes and the monitor is properly tracking the patient’s underlying rhythm.

 

Success! You’ve supported the patient through his bradycardic ordeal (hitting a lowest-recorded HR of 10 bpm) and now he has resumed a sinus rhythm of his own volition. A 12-lead ECG is captured.

Sinus rhythm at 75 bpm,

Sinus rhythm at 77 bpm, first-degree AV-block, left bundle branch block, left axis deviation, poor R-wave progression.

 

The rest of the patient’s emergency department and intensive care unit course is uneventful (and his labs—including potassium—unremarkable) and he is discharged back home in healthy condition—with the addition of an implanted pacemaker.

 

For the sake of brevity today’s discussion only focused on identifying electrical capture. Stay tuned for Part 2 of this case where we discuss two objective methods of confirming mechanical capture.

Can’t get enough TCP?  As a companion to the original article by Tom, Christopher Watford wrote a second in-depth review examining just why we miss false capture so often.

Alternatively, check out everything our blog has written on the topic of transcutaneous pacing.

Transcutaneous Pacing Success!!! Part 1

Anyone trained in transcutaneous pacing (TCP) needs to be able to identify the rhythm below instantly.

False-capture with transcutaneous pacing.

Successful transcutaneous pacing?

It shows a patient being transcutaneously paced at 80 bpm and 125 mA on a LifePak 12 [the strip is labelled 130 mA but that refers to a point just past the end of the paper, I promise].

Well, actually, it shows attempted pacing. Despite the generous current being delivered there is no evidence of successful electrical capture. Without electrical capture there cannot be mechanical capture, so the patient’s pulse at the moment is actually 10 bpm.

Here are the patient’s two native QRS complexes—the only ones generating a cardiac output as a result of his exceedingly slow baseline rhythm.

Though they resemble QRS complexes, the fourteen other “blips” you see on the strip are actually just artifact from the pacer. This phenomenon is commonly referred to as “false capture” and it is a huge problem.

 

The Problem of False Capture

On November 12, 2008, Tom Bouthillet published an article on this blog that hit me as a revelation and changed the way I approach transcutaneous pacing.

Transcutaneous Pacing (TCP) – The Problem of False Capture

You need to go read his article right now. I’ll wait here.

Learn something.

Before encountering that post I had no idea how difficult it could be to achieve and identify successful transcutaneous pacing. Since then I’ve seen dozens of cases of attempted TCP—both in person and shared by colleagues and readers—but very few of them have demonstrated even intermittent capture.

The catch is that, in most of those cases, the treating providers were absolutely certain they had achieved good capture. Patients woke up; non-invasive blood pressures improves; mechanical capture was confirmed with pulse palpation—but regardless of how confident the team managing the patient was, in almost every case the rhythm strips they showed me were pathognomic of false capture.

Tom turned me into a TCP skeptic and that is in every way a good thing.

I don’t care how strong a patient’s radial pulse feels while they are being transcutaneously paced; you cannot have mechanical capture without electrical capture. And without true mechanical capture, any improvement in the patient’s condition is merely the result of noxious stimuli being provided 60–80 times a minute; often for hours on end. The patient might become more alert, but not because their heart rate has increased significantly.

Patients get admitted overnight on ineffective transcutaneous pacing.

While pacing isn’t always a terrible experience if the current is increased slowly and the patient understands what is going on, being shocked all night to zero benefit sounds like torture to me.

Again, for more information on the problem of false-capture and how to identify ineffective pacing go re-read Tom’s article, but what follows is a case that demonstrates false-capture, true-capture, and two objective ways of confirming mechanical capture.

 

The Case

The details of the case are not overly relevant, but let’s say a patient presents quite unwell with a pulse of 20 bpm. No es bueno. Here is his initial 12-lead:

A very sick heart.

Sinus rhythm w/ marked sinus arrhythmia, high-grade AV-block (fixed PR-interval), and RBBB. There is not a single measurement or computerized statement that I agree with here. Remember: the sicker your patient, the less useful the machine’s diagnosis becomes.

 

Atropine is administered and fails to improve the heart rate. Time to start transcutaneous pacing.

Complete heart block with a ventricular rate of 15 bpm.

With “demand” pacing turned on (usually the default), the machine tracks the native QRS complexes—as evidenced by the inverted triangles just above each QRS—but since it is set to 0 mA no current is delivered and there are no pacing spikes.  The rhythm here appears to be complete heart block with a ventricular rate of approximately 15 bpm.

 

The current is increased from 0 mA to 10 mA.

TCP at 10 mA with no capture.

There are prominent pacing spikes at 80 bpm with tiny blips after them that almost look like P-waves (they’re not). You can see the patient’s underlying rhythm marching through at approximately 20 bpm and being tracked by the monitor.

 

The current is increased from 10 mA to 30 mA.

TCP at 30 mA with no capture.

This strip looks very similar to the prior tracing except that the blips following the pacer spikes seem slightly deeper.

 

The current is increased from 30 mA to 50 mA.

TCP at 50 mA with no capture.

Similar to the last tracing, but the post-pacer blips are definitely deeper.

 

The current is increased from 50 mA to 70 mA.

TCP at 70 mA with no capture.

More of the same. Still no capture.

 

The current is increased from 70 mA to 90 mA.

TCP at 90 mA with no capture.

Sensing a pattern?

 

Most providers give up on transcutaneous pacing before even reaching 90 mA but, having read Tom’s article, you know that is a fallacy.

The current is increased from 90 mA to 110 mA.

TCP at 110 mA with no capture.

More of the same pattern and still no capture.

 

Keep going…

The current is increased from 110 mA to 125 mA.

TCP at 125 mA with no capture.

This is the same tracing shown at the top of this article. After deliberately walking our way up from 10 mA does it still look like there could be capture?

 

Don’t give up yet…

The current is increased from 125 mA to 130 mA.

TCP at 130 mA with intermittent capture.

Finally! A Change!

We finally see a few complexes that demonstrate true capture! Note how the capture beats are followed by wide, obvious T-waves, while the false-capture pacer artifacts are only followed by diminutive pseudo-T-waves.

 

Spurred on by signs of success, the current is increased to 135 mA.

TCP at 135 mA with mostly successful capture.

Mostly capture! There are two pacer spikes without capture but the majority of the rhythm is finally composed of complexes that show true electrical capture.

 

The patient will be leaving the emergency department to go to radiology so the current is increased from 135 mA to 145 to ensure safe capture through the trip. Just before leaving the resus bay a problem is noted though…

TCP at 145 mA with an episode of failed capture.

It looks like we’re losing capture…

What started out as a couple of dropped complexes has progressed to a string of six non-captured pacer spikes… This will not do.

Time to up the current a bit more to 150 mA.

TCP at 150 mA with mostly successful capture.

This is a bit better but there are still a couple of non-capture beats. That is, until…

TCP at 150 mA with an episode of failed capture.

Gah! Lost capture again! This patient is never going to make it to radiology.

 

The current is increased to 155 mA…

TCP at 155 mA with several episodes of failed capture.

Ugh, still no consistent capture.

 

Not one to give up, you increase the current to 165 mA. Remember: Tom taught us that the monitors go up to 200 mA for a reason—if a patient needs 200 mA to capture and stay alive then that is simply what they need. The rate is also decreased to 70 bpm (just because).

100% transcutaneously paced rhythm at 165 mA and 70 bpm.

Finally! This strip shows a 100% transcutaneously paced rhythm. Note: this is lead II.

We finally see consistent 100% capture; a pattern which continues through the patient’s trip to radiology and the the next hour.

Note that the above strip shows lead II—below are two more strips with the same 100% paced pattern but viewed through leads I and III (just to show how pacing can look different depending on the lead used).

Successful transcutaneously paced rhythm as seen in lead I. The pause at the start of the strip is suspicious for a non-conducted pacer spike but since it’s not well visualized we won’t worry about it here.

Successful transcutaneously paced rhythm as seen in lead III.

 

Below is one more perspective of successful electrical capture—this time from a GE DASH bedside monitor.

Successful capture on a GE DASH monitor. Note that at this point the setting for the rate has been decreased to 50 bpm.

Successful capture on a GE DASH monitor. Note that at this point in the resus the pacing rate has been decreased to 50 bpm.

 

An hour later, after the patient has stabilized, a change is noted on the monitor.

This strip shows sinus rhythm at 75 bpm with a first-degree AV-block. There are no paced complexes and the monitor is properly tracking the patient’s underlying rhythm.

 

Success! You’ve supported the patient through his bradycardic ordeal (hitting a lowest-recorded HR of 10 bpm) and now he has resumed a sinus rhythm of his own volition. A 12-lead ECG is captured.

Sinus rhythm at 75 bpm,

Sinus rhythm at 77 bpm, first-degree AV-block, left bundle branch block, left axis deviation, poor R-wave progression.

 

The rest of the patient’s emergency department and intensive care unit course is uneventful (and his labs—including potassium—unremarkable) and he is discharged back home in healthy condition—with the addition of an implanted pacemaker.

 

For the sake of brevity today’s discussion only focused on identifying electrical capture. Stay tuned for Part 2 of this case where we discuss two objective methods of confirming mechanical capture.

Can’t get enough TCP?  As a companion to the original article by Tom, Christopher Watford wrote a second in-depth review examining just why we miss false capture so often.

Alternatively, check out everything our blog has written on the topic of transcutaneous pacing.

Revolutionizing Pediatric Resuscitation, JEMS Games Finals, and a Very Serious Topic #EMSToday2015

Friday, February 27

Okay, I admit it. I’m 43 years old and I can’t party like I used to. I needed a little help yesterday morning after ZOLL SHOCKFEST. But, I had an important meeting to attend with three amazing women who keep the trains running on time at EMS Today 2015 – MaryBeth DeWitt (@dewittmarybeth), Deborah Murray, and Amanda Brumby (@AmandaBrumby). It was really nice to put faces to names and share thoughts and observations about education, event planning, and social media. A.J. is incredibly fortunate to have these capable, professional women working behind the scenes to make EMS Today 2015 a success!

Exhibit Hall

From there Kelly (@barefootNurse24) and I headed down to the Exhibit Hall to take in the sights and chat with old friends. I had planned on catching up with Matt Fiske from Physio-Control (@PhysioControl) but he was recalled back to Seattle so I shared a life-saving story with John Friederich involving a Lifepak 12, a wedding party, and a Boy Scout and got myself a nice challenge coin!

LP12_challenge_coin

Pediatric Resuscitation

I had the pleasure of meeting EMS 10 Award winner Peter Antevy M.D. (@Handtevy) at the EMS 10 Awards this year we hit it off right away. My department has recently developed a beta version of Pediatric Pit Crew CPR and we recently pulled the Broselow bags (but not the Broselow tapes) off the ambulances — which was controversial — so it was really interesting when Peter started challenging me and asking me how I would accomplish various things like mixing up D25.

I was really enjoying the dialog, but it was the end of the night, so I gladly accepted when he invited me to attend at least one of his classes.

Psychological Wiring and Pediatric Resuscitation

peter_antevy

I spend a lot of time thinking about human performance, team dynamics, and decision making under stress, so this presentation really hit home with me!

At a time when Adult Pit Crew CPR has swept the nation, EMS is working adult sudden cardiac arrest on scene for at least 20 minutes prior to transport, and survival rates have increased nationally, why have survival rates for pediatric cardiac arrest remained flat?

If you’re like me, you might say, “because pediatric cardiac arrest is not like adult sudden cardiac arrest — it’s more likely to be asphyxial — and the prognosis is not as good in the first place.” But there’s more to that story.

Let’s be honest. What do we tend to do with kids? We scoop and run. Why do we do this when we know that it’s bad? We do it because it’s really scary, we’re not comfortable, and we become overwhelmed. Dr. Antevy persuasively argues that this is perfectly normal human behavior. Specifically, it has to do with System 1 and System 2 thinking.

System 1

  • Fast
  • Automatic
  • Frequent
  • Emotional
  • Stereotypic
  • Subconscious

System 2

  • Slow
  • Effortful
  • Infrequent
  • Logical
  • Calculating
  • Conscious

By making pediatric cardiac arrest so “different” from adult sudden cardiac arrest (to the point where the AHA has an entirely separate course for it), by requiring us to perform math under stress, and because we have to perform under the watchful eye of highly concerned parents, our System 2 thinking is easily overwhelmed. When that happens, we revert to System 1 — we all do — there are no exceptions.

When you revert to System 1 under stress you are no longer thinking rationally. You are reacting instinctively and you will ignore whatever you have to ignore (including logic or good advice) to extract yourself from the crisis. As a side note, this finally helps me understand why so many EMTs and paramedics are quick to separate children from parents (which has bothered me for a long time).

Once we understand System 1 and System 2 thinking, and once we admit that System 2 thinking is useless in an emergency situation, we can begin to develop effective System 1 strategies to ensure that our actions are helpful during an emergency. One of the ways we can do that is make pediatric resuscitation more like adult resuscitation.

  • A – Airway
  • B – BVM
  • C – Compressions
  • D – Drill (IO)
  • E – Epinephrine

Importantly, WE MUST ELIMINATE MATH. One of my most popular tweets this week was this quote from Dr. Antevy: “I’m really good at math. I’m terrible at math during a code.” Some of us aren’t very good at math in the first place.

Pediatric Calculations Made Simple

When you actually start going through scenarios it doesn’t take long to realize that those of us who do not work in pediatrics every single day have no idea how to accurately calculate, draw up, and administer medications to children safely. In many cases, we don’t even have the correct equipment to make it happen (and I’m talking about the equipment inside the Broselow bag).

Try this experiment next time you’re at work. Find a really smart paramedic and say, “You have a 6 month old female in cardiac arrest. She is 8 kg. Draw up the correct dose of Epi 1:10,000. Please hurry.”

Even if the paramedic realizes the correct does is 0.8 ml of Epi 1:10,000 has he or she ever used a 1 ml syringe to draw epinephrine from 10 ml pre-filled syringe of Epi 1:10,000? Probably not. Now imagine doing it in front of the child’s parent. Can you see how vulnerable System 2 is to the crash and burn?

antevy_system

Whatever we do it must be fast, simple, accurate, and achievable. We must convert these things into System 1 processes or we will not be able to pull them off on an emergency scene.

That is the basis of Dr. Antevy’s Pediatric Emergency Standards (Facebook). I urge you to check it out for the benefit of your EMS system and the children in your community. If EMS does not perform an effective resuscitation at the scene it is likely that the child will not survive.

Congratulations to Dr. Antevy on his EMS 10 Award! I’m looking forward to brining this back to my EMS system.

JEMS Games Finals

From there it was off to the JEMS Games Finals. What an amazing job! The scenario included a helicopter crash, multiple traumas, a swarm or angry bees, and acute anaphylaxis. The finalists included Boca Raton Team B, FDNY EMS, and Cumberland County EMS.

Boca_Team_B

All three teams did an amazing job! The judges definitely have their work cut out for them! Keep your eyes on the #EMSToday2015 hashtag on Twitter. The winner will be announced very soon!

jems_games_competitors

Photo credit: @Handtevy

Update: Congratulations to FDNY EMS (first place) and Boca Raton Team B (second place) in the JEMS Games!

ZOLL Blogger Bash

Kelly and I headed out to the Bubba Gump Shrimp Co. for the ZOLL Blogger Bash. It was great seeing some familiar faces in this time honored tradition. I even got caught up with Tim Noonan the Rogue Medic! Ted Setla (@setla) was already there after doing a ride along with our good friend Random Ward (@WmRandomWard) who is a paramedic with Baltimore Fire. Ted took some awesome pictures as usual!

Baltimore

Baltimore_Fire_EMS

I got to talk shop a little bit with the folks at ZOLL (@zollemsfire) and explain to them our needs when it comes to post-event analysis and entering cardiac arrest data into the CARES registry. As always, they were interested in what they can do to make their products even better to meet the needs of the EMS market! Special thanks to Charlotte for inviting Kelly and me!

A Very Serious Topic

As we so often do we ended up back at the Pratt Street Ale House where Ted, Kelly, and I ran into Mike McEvoy (@mcevoymike) and Jon B. (@EMTLife). We ended up discussing EMT and paramedic suicide. This is a difficult topic, and let’s face it, we in EMS are bunch of jaded, sarcastic, and twisted individuals who have developed all sorts of defensive mechanisms, including dark humor, to cope with our extraordinarily difficult jobs. I’d be lying if I said this conversation was any different.

But we must have this conversation.

Too many of us in the emergency services are ending our own lives. I vow to go back to my department and be a better friend and a better listener to my coworkers. I want to let them know that I care and that they matter to me individually. I hope you will all do the same. None of us really knows the burden other people carry with them. A single kind word can be a powerful force. Who knows? It might just be the thing that makes the difference.

Thanks for following me this week!

Meetings, Great Classes, and Celebration! #EMSToday2015

Thursday, February 26

My day started early (these blog posts don’t write themselves you know!) and then I was off to my first ever JEMS Editorial Board meeting. As the “new guy” I had resolved not to cause too much trouble. A.J. Heightman (@AJHeightman) was suffering a bit of laryngitis which gave everyone good-natured laugh at A.J.’s expense.

Everyone around the room gave a short introduction and spoke the things they were passionate about (or interested in) regarding EMS and then about the things they were concerned about. It was interesting to hear some of the common themes.

Passionate about:

Measuring outcomes using data, quality benchmarking (what we should measure and how we should measure it), using STEMI and sudden cardiac arrest as the “foot in the door” that leads to more collaboration between EMS and hospitals, succession planning (not just in EMS systems but also among the national leadership), meeting patients’ needs using unconventional resources, finding innovative ways to obtain reimbursement, technology, the emergence of social media and FOAM (Free Open-Access Medical Education) as a force to be reckoned with.

Concerned  about:

The educational standards for EMS professionals in the U.S. compared to our colleagues in Canada, Australia, and the U.K., too many EMS systems have “their heads in the sand” regarding the changes in health care and how EMS needs to adapt to meet patients’ needs, the over-emphasis on cardiac arrest as a performance measure, the fact that EMS represents 80% of the call volume of most fire departments yet skulks in the corner at budget time, the generation gap between the “old guard” and the “new guard” in EMS (acknowledgement that we could have done / can do a better job developing new leaders to take our place), the lack of peer-review in FOAM.

Speaking of FOAM and the #FOAMed hashtag on Twitter (and it’s little brother #FOAMems) I was surprised at how many members of the Editorial Board were completely unfamiliar with it! Rob Lawrence (@wotsukrobl) was a notable exception. I get the feeling a lot of them don’t use Twitter.

Sometimes I forget there is a substantial “digital divide” among the current generations (even though I am Generation X and did not “grow up with the internet” most of my generation was quick to adopt social media). I pointed out that the #FOAMed hashtag on Twitter had hundreds of millions of impressions on Twitter last year (and will surely surpass 1 billion impressions in 2015). That’s a lot of tweets!

FOAMed

Speaking of hashtags on Twitter the #EMSToday2015 hashtag has really taken off and I couldn’t be happier!

EMSToday2015

There have now been over 4.4 million impressions since the beginning of the month! This is an awesome demonstration of how social media tools can enhance everyone’s experience who attends a conference. In addition, it helps others who were not able to attend the conference follow the action from home.

JEMS Games

I was tied up in a series of meetings all afternoon but I had my spies at the JEMS Games! Michael Herbert (@bigGermanMike) turned me on to an interesting technique that #TeamAut used that he called “Kiwi CPR”. I thought it was notable and Mike was kind enough to write it up for me.

Kiwi CPR

#TeamAUT showing-off Kiwi-CPR

If you looked at the purpose of the JEMS Games, you would see that it is intended to “to create a fun, challenging and educational experience for emergency medical personnel that results in them being better prepared for the challenges they may encounter in the field.”

Yesterday, at the JEMS Games #TeamAUT from New Zealand took the stage in a challenging scenario that required them to work a cardiac arrest while navigating an obstacle course. Although the best practice is to work a cardiac arrest on scene and defer transporting a victim until return of spontaneous circulation (ROSC), occasionally special considerations do require the movement of the patient while attempting to perform CPR.

#TeamAUT approached this challenging scenario with a technique that caught our attention. The patient was placed on a backboard and loaded onto a stretcher with the inferior portion of the board extending approximately two feet below the stretcher. This allowed one of the rescuers to kneel superior to the patient and perform chest compressions from an “Over the Head” position. The stretcher was able to be moved through the obstacle course while high quality compressions were being performed seamlessly.

Following the competition, I asked Team AUT, which comprised of Brendan Wood, Sarah Gordon, Luke Summers, and Haydn Drake (@paramedickiwi) about this unusual technique and I was amazed to find that this method has been tested. The Head of Discipline for the AUT Paramedicine & Emergency Medicine department, Paul Davey, has tested “Kiwi-CPR” by measuring the difference in “over-the-head” compressions versus standard “from-the-side” compressions by looking at factors like depth, recoil, and CPR fraction time and found there was no significant difference between these two groups.

#TeamAUT used this technique to perform high quality compressions while moving a patient on a stretcher during the JEMS Games and introduced the wider world to their technique. Hat tip to “Kiwi-CPR” and to our friends, Brendan, Sarah, Luke, and Haydn!

EMS Compass

nick greg tom

During lunch Kelly (@barefootNurse24) and I attended a meeting across the street at The Hilton where our good friend Nick Nudell (@RunMedic) who now heads up the National EMS Performance Measures Project for NASEMSO and NHTSA was giving an overview of the EMS Compass initiative.

Greg Friese (@gfriese) from EMS1.com gives a nice overview here. This is an important project that anyone concerned about EMS quality should be knowledgeable about! It made Kelly and I laugh when Greg tweeted a picture of us covering the session!

kelly tom

We had another meeting with Matt Womble about the Emergency Medical Error Reduction Group (EMERG) Patient Safety Organization (PSO) — which I hope to cover in more depth on another occasion — and then headed down to the Exhibit Hall.

Exhibit Hall

Our good friends at ZOLL gave us a sneak peak at some new products including their post-event software for cardiac arrest analysis.

TOM Q-CPR

I also spent some time with Paul Stoddard and the folks from Philips Healthcare. One of those folks was Dan Carlascio (@DanCarlascio) who was the first person to ever have me teach a 12-lead ECG class in the CCEMT-P course (many years ago at Loyola University in Chicago – I won’t say how many years ago but it was > 10 years).

They were a great bunch and I tested out their Q-CPR Measurement and Feedback Tool.

ZOLL SHOCKFEST

I have a meeting this morning so there isn’t time to do this justice! All I can tell you is that if you missed ZOLL SHOCKFEST last night you missed a great party. Not only did A.J. Heightman perform CPR on a mechanical bull (I’m holding on to that video for ransom), but we enjoyed amazing fellowship with colleagues from around the world and made friendships that I sincerely hope will last a lifetime!

TeamAUT_TeamLondon

I can’t tell you how honored and privileged I felt to be among this special group of people. This conference just keeps getting better and better! To see more of the action from last night check out the #zollshockfest hashtag on Twitter!

Ted Setla (@setla) let me take pictures with his AMAZING camera which was a lot of fun!

Stay tuned! Follow me on Twitter at @tbouthillet for more updates about the conference.

See also:

From Precons to EMS 10 Awards and Nightwatch! #EMSToday2015

From Precons to EMS 10 Awards and Nightwatch! #EMSToday2015

Wednesday, February 25, 2015

What an awesome day at EMS Today 2015! Kelly and I headed over to the Convention Center to get registered and ran into our very good friends Nick Nudell (@RunMedic), Chris Montera (@geekymedic), and Anne Robinson Montera (@CaringAnne).

Nick and I started the EKG Club many years ago as an email-based discussion group. It is now a thriving Facebook group that you should check out! We’ve also done some interesting consulting work together in the implantable medical device industry.

Chris and Anne are one of the “power couples” of EMS and are very influential in Community Paramedicine (more on that later).

Advanced Airway Cadaver Lab

After getting registered we headed over to the Advanced Airway Cadaver Lab which is put on by the Paragon Medical Education Group (@ParagonMedEd). It was really great because Kelly and I had met Jim Logan at a previous EMS 10 Awards event and got along great. I had also recently met Joe Holley, M.D. (@joeholley) on Twitter so they were expecting us. What an awesome experience!

As a side note, social media has become an indispensable tool at medical conferences!

Cadaver_Lab

Everyone in the cadaver lab was dressed in full PPE including mask, gown, gloves, and hair covers. So it was a surprise when I heard a British accent say, “Are you that blogger Tom?” I said, “Yes, I am!” Well guess what? It was Team London (#TeamLondon)! We started chatting and I couldn’t help but tell them how much respect I have for the London Ambulance Service. When I brought up the Code STEMI Web Series they said, “You know Mark Whitbread is here. He’s over at the Resuscitation Academy right now!”

It’s been 3 years so we had to head over and see it for ourselves!

Resuscitation Academy

The moment we walked into the Resuscitation Academy we were greeted by our good friend Mike Helbock (@medicme). Mike is one of the smartest guys I know and he is always very generous with his time and knowledge. Kelly and I had dinner with him when we were in Seattle and he told us all about the history of King County Medic One, how it got started, and how they operate. It was fascinating.

I said, “Hey Mike do you mind if I take some pictures?” and he said, “You can do anything you want!” which cracked me up.

As it turned out it was getting toward the end of the morning session and they were about to do a full code scenario. Guess who was right in the middle of the action? The one and only Mark Whitbread from the London Ambulance Service!

Resuscitation_Academy_Whitbread

If you haven’t seen the London episode of the Code STEMI Web Series you need to watch it. It’s an incredible system! It was great to see Mark but we had one more stop to make!

Advanced Community Paramedicine Workshop 

We arrived at the Advanced Community Paramedicine Workshop just in time to see a presentation about 2-1-1 San Diego and how it connects people who are struggling with appropriate resources. Immediately afterward our good friend Chris Montera (@geekymedic) talked about a case study from Eagle County Paramedic Services in Colorado.

Chris_Montera

After Chris’s presentation Kelly and I had a nice conversation with Matt Zavadsky (@MattZavadsky) from MedStar Mobile Healthcare. He’s a very well known guy in Community Paramedicine so it was nice to hear his perspective about 2-1-1 San Diego. Anyone who wants a nice introduction to Community Paramedicine can attend Introduction to Community Paramedicine today from 10:30 a.m. – 12:00 p.m.

Pratt Street Ale House

After a quick lunch at the Diamond Tavern (and another run-in with Team London) Kelly and I headed over to the Pratt Street Ale House where we met up with Thaddeus Setla (@setla), Scott Kier (@MedicSBK), Jeff Sorenson (@chicagomedic), Michael Herbert (@BigGermanMike), and several others (I hope they will forgive me for leaving them out). Things were just starting to get interesting when it was time for Kelly and I to head back to the room and get ready for the EMS 10 Awards.

Ted_Hayden_Pratt

Of course we just missed Hayden Drake (@paramedickiwi) from Team AUT!

By the way, the #EMSToday2015 hashtag on Twitter is really blowing up with some great stuff!

EMS 10 Awards

It’s always a real pleasure and distinct honor to share an evening with some of the greatest innovators in EMS and the EMS 10 Awards is a place where that is always guaranteed to happen! But, there’s one group that really stole the show and that was the crew from Nightwatch!

Nightwatch_Kelly

Left-to-right: Titus Tero (@NightwatchTitus), Dan Flynn (@Nightwatch_Dan), Kelly Arashin (@BarefootNurse24), Keeley Williams (@nightwatchmedic), Holly Monteleone (@NightwatchHolly), and Nick Manning (@Nightwatch_Nick)

It was impossible to not be impressed. They are a very genuine, and very gracious, group of top-notch EMS professionals! They really do the EMS profession and the City of New Orleans proud. Ken Bouvier is doing something right. That is obvious! Don’t miss your opportunity to meet the crew from Nightwatch. They will hanging out with the good folks from Physio-Control (@PhysioControl) at Booth 804.

There’s much more to say about the EMS 10 Awards and the very deserving awardees but I must get ready for my first-ever JEMS Editorial Board meeting which is sure to be interesting!

Stay tuned. This conference is just getting started! Follow me on Twitter at @tbouthillet.