Snow Shoveling is Bad

The two-day blizzard that your town endured has just ended.  The area received about a foot of snow, but now it is sunny out.  You and your partner are assigned to the report of chest pain at a little house in the southeast corner of your jurisdiction.  When you arrive, the residential street is unplowed and it doesn’t look like your ambulance will be able to make it to the patient’s driveway.  So you park on the main street and walk four houses up to the address with your gear.  The patient’s house’s driveway is half-shoveled, so you have an idea of what is going on before even entering the house.

Inside, you find a 60-year old male patient complaining of 10 out of 10 chest pain that he describes as squeezing.  The pain radiates to his left shoulder, and he states that it feels like he isn’t getting enough air.  The pain started about an hour ago, while he was… wait for it… shoveling snow.  He is warm, pink, and dry.  His wife reports a history of hypertension and hyperlipidemia, for which he takes lisinopril and a statin that they can’t name.  The patient had a “heart attack” 15 years ago, but this pain is not similar to that episode – as he remembers it, the prior episode was much less severe compared to now.

The patient’s blood pressure is 110/70, heart rate of 40, respiratory rate of 20, and a pulse ox reading of 98% on room air.  You ask your partner to place the patient on oxygen via nasal cannula and run a 12-lead ECG.  Click to enlarge:

Courtesy DogMan41 via Wikimedia Commons, with permission.

 What is your interpretation of this ECG?  What is your plan?

This is a Second Degree AV Block with Fixed 2:1 Conduction.  The atrial rate is approximately 80 and the ventricular rate is approximately 40.  The PR interval is normal at 0.12 and the QRS duration is narrow – 0.08.  The axis is normal and there are no signs of chamber enlargement.  There are Q waves from V1-V4, the zone of transition is late, and there is ST elevation in the inferior leads with ST depression everywhere else.  The T waves are pretty large in comparison to the QRSs.

This brings us to what I wanted to talk about: Second Degree AV Blocks.  There are three kinds of 2° AV blocks.  They are Type I (Wenckebach), Type II, and 2:1 conductors.  All have the same issue going on: A P wave that doesn’t cause ventricular firing when it should.  This means that the P wave fell at a time when the ventricles can be assumed to be repolarized – the P wave falls well after the T wave.  This is why blocked PACs, for example, aren’t 2° AV blocks.  PACs can fall so prematurely that the ventricles are not yet repolarized.  This isn’t the case in 2° AV blocks.

A 2° AV Block Type I has a progressively lengthening PR interval, a non-conducted P wave (making it a 2° AV block), then the PR interval pattern resets.  The QRS duration is usually narrow, and if rate assistance is needed the rhythm usually responds well to atropine.  Type Is are more commonly associated with inferior MIs, but the MI is not specifically necessary.

A 2° AV Block Type II is an extremely rare rhythm.  These have consistent PR intervals with occasional non-conducted P waves.  In contrast to Type Is, a Type II can have multiple non-conducted P waves in a row.  The damage to the myocardium that results in this rhythm is more extensive, so the QRS duration is almost always wide.  Type IIs do not usually respond to atropine, and pacing is almost always required.  Type IIs are more commonly associated with anterior MIs, and can progress to Complete Heart Blocks or ventricular asystole (no QRSs, just P waves marching along) suddenly.  These rhythms cause medics to go pale and sweat – these are dangerous.

So you can see that the difference between a Type I and a Type II is whether the PR interval is lengthening or constant.  Thus, you need at least two PR intervals consecutively to compare before a dropped beat: You need a PR interval ‘A’ to compare to PR interval ‘B’.  You have to compare the first PR interval to the second PR interval.  You can’t compare two first PR intervals.  Since the non-conducted P wave can reset the cycle, you need the comparison PR intervals to be between two dropped Ps: You need at least 3:2 AV conduction to be going on, but 4:3 or 20:19 or whatever works just as well.  However it works, you have to compare the first PR interval after the non-conducted P to the second PR interval.  You can’t compare two first PR intervals. 

What if you have 2:1 conduction?  You can’t technically tell if it is a Type I or a Type II.  So you should call it what you know it is: Second Degree AV Block with Fixed 2:1 Conduction.  Look at the ECG above, with the P waves noted.  Two to one atrial-ventricular conduction:

We can surmise that it is probably a Type I with 2:1 conduction going on for a couple of reasons.  First, there is an inferior MI, which is more commonly associated with Type Is.  Second, the QRS duration is narrow, which would be unusual in a Type II.  But when you look back above at the definitions, the words usually appear.  So there is no way to be technically positive, 100% sure.  The Q waves and late transition in the V-leads are probably an old anterior MI – maybe the one from 15 years ago, but again there is no way for us to be positive in a dude’s living room.

What’s your plan for this gent?

Hopefully it involves titrating his O2 delivery to maintain saturations of 100%, aspirin, and fentanyl, with rapid transport and early hospital notification.  Is this a STEMI alert?

I should say so.  This fellow is almost certainly having an acute inferior myocardial infarction.  Would you give him nitroglycerin?

Well, that’s a discussion for another day.  This post is long enough as it is.  My preview answer is that I would, if he met a couple of criteria.   See you next week for that discussion, and we’ll see if I can convince you too.

Left or Right?

Picture yourself in your ambulance, at a post, waiting on your next call.  After a few minutes (probably right after you recline your seat and pull your hat down over your eyes – dispatchers do use hidden crew comfort sensors, after all), you are assigned to an emergency call a couple miles northwest of your current location.  You are in a city that has a grid layout, without many diagonal streets.

For this scenario, let’s assume that each street you choose is a main route without noticeable difference in speeds or traffic volume. You are faced with the “two sides of a square” issue.  You could go north then west, or you could go west first and then north.  Which route do you take?

UPS delivery drivers would take the west-then-north route, because it involves a right turn.  UPS has optimized their routing since the early 2000s to minimize left turns.  I thought it was an urban legend, but there are several articles available on the subject.  It was even tested on Discovery Channel’s Mythbusters show. 

Turning right at an intersection is better for UPS in a few ways.  First, time is saved because the driver doesn’t have to wait for oncoming traffic to clear before making the left turn.  Sitting and idling while waiting for the green left-turn arrow is bad for fuel and time.  Second, right turns can usually be made through red lights.  Idling at the light is reduced, saving fuel and time.  UPS reports that approximately 90% of their turns are right turns.  It got me to thinking about whether that would hold true for ambulance routing during emergency (lights and siren) travel.  Should I be trying to route for right turns, as well?

After thinking about it, I don’t think it does.  I think emergency ambulances should prefer to make left turns.  I don't have academic studies from peer-reviewed journals to cite, but let me see if I can convince you with logic.

The two main reasons to prefer right turns don’t hold true when you are bright, flashy, and making a lot of noise.  Oncoming traffic will stop for your left turn.  Right turns are more dangerous during emergency response.  Let me show you a poorly drawn example:

You pull up to this intersection, intending to make a right turn, where the 1-3 lanes are blocked.*  Which lane would you use? 

The turn lane, correct?  I would.  It would probably take too long to push the four cars through the #3 lane, against the light, to make the right turn.  The problem is that using the turn lane signals to other drivers that the vehicle in that lane is turning left.  It is subconscious.  Vehicles in the turn lane turn.  Other drivers probably don’t even have much of a conscious thought about it, outside of being glad that the ambulance isn’t behind them. 

Turning right from the left lanes is a problematic situation:

Arrows that cross are bad.

If the light changes to green (and if you are in a city with signal preemption devices it will) the cars in the three through lanes are able to go forward – which they will do if they are distracted, not attentive, or in a hurry.  In an ambulance, that is hard to see what’s going on in those lanes because your lateral view is blocked by the ambulance box.  Your partner could roll down his/her window and hang out of it to see those lanes, but that doesn't look especially cool or work very well.

Left turns are better:

No crossing arrows. Visibility is better to look at oncoming traffic, rather than traffic behind you to your right.

I’ve been involved in at least one grinder by turning right in an emergency vehicle with other cars on my right.  I’ve seen or heard of several other ambulance crashes that result from this situation.  Left turns are safer in an ambulance and the efficiency issues that UPS is trying to overcome don’t apply to emergency travel.  So going back to the initial scenario, I think the north-then-west route is best for the ambulance to take.

What do you think?  Did I convince you of the logic behind emergency lefts?

*Lanes are numbered from left to right, not counting turn lanes – like reading.  The left lane is #1, the center lane is #2, and the right lane is #3.

The Johnston Sign, Or: I Think My Patient is Faking

It is a dark and stormy night when you are dispatched to a downtown fast food restaurant on the report of chest pain. You arrive to find the restaurant manager explaining how the patient was homeless and had stretched a cup of coffee across several hours. But he had been quiet, inoffensive, and mellow so the employees had decided to let him hang out. "Now that it's closing time he has heart problems," he finishes with an eye roll.

You approach the patient and ask what's going on. The patient is sitting in a chair, holding his right fist against his sternum in a precordial salute. His eyes are squinted closed and his head is rolling from side to side. He whispers his response, 
"My chest hurts…"  
When you ask other questions, he declines to answer. 
"I can't talk anymore...  It hurts so bad I think I'm dying..."

His vital signs are normal. His speech is whispered, but not breath dependent - he speaks in full (but quiet) sentences. His breath and tracheal sounds are normal, as is his oxygen saturation.  His skin is warm, pink, and dry. The 12-lead ECG shows a normal sinus rhythm without ST segment, T wave changes, or ectopy.

Johnston Sign. Squinty eyes, whispering in full sentences, rolling head, occasionally going limp for no reason, and an overly dramatic presentation that does not match objective findings. This is the Johnston Sign.

Soccer player, on the ground, writhing in extreme agony.  Johnston Sign.
(By Thomas Sørenes via Wikimedia Commons)

The Johnston Sign was created years ago (by me, after an irritating night) to explain a patient who was dramatically faking. There are no objective signs of a problem.  Everything matches a bad actor on a poor TV show. Most patients haven't seen as many sick people as you have. The closest they come is to see an actor (who probably hasn't seen many truly sick people either) play sick on House, ER, or Grey's Anatomy. You have the advantage, because you've seen how people actually present when they're fixing to die.

Experienced medics know that dyspnea is an issue of volume – but inspiratory/expiratory volume, not auditory volume. Even severely dyspneic patients don't whisper; they can only get one word per inhalation but you can hear the one word. Chest pain has nothing to do with squinty eyes. Dizziness doesn't result in rolling your head around.  Spontaneous episodes of limpness? Please.

Faker!  The patient in the scenario doesn't want to go out in the cold and would rather go to a warm ED!

It is never that simple in EMS. I am very sorry to admit that the Johnston Sign sucks as a diagnostic or decision-making tool.*  Fakers sometimes aren't faking, sometimes they aren't bright enough to complain about their actual problem, sometimes they are poor communicators, sometimes they think you won't believe them so they build it up, the list goes on and on.

There are five main variations** of behavior that can fall under the umbrella term of "faking medical problems." Three are real mental health issues requiring diagnosis, care, and treatment by a competent professional. One is a diagnosis of exclusion that prehospital providers are ill-equipped to determine.  The final one is dangerous and embarrassing - it doesn't even approach EMS Rule #2: Look cool.

• Conversion disorder/Functional neurological syndrome: Mental health disorder in which stress presents as neurologic complaints like seizures or blindness. There is real suffering here.  Not faking.
• Somatic symptom disorder: Mental health disorder with real complaints such as pain, nausea, rashes, dizziness, and such. The cause or severity of the complaints can't be easily assigned to a medical diagnosis. These patients can be very frustrated with the inability of medical science to find a solid, treatable diagnosis. Again, there is real suffering here.  Not faking.
• Factitious disorder/Non-accidental illness: Mental health disorder where people badly want to be a patient, so they induce or feign illness. Being a patient means that they get care, nurturing, and sympathy. So they are gaining something, but not anything tangible or physical. Keep in mind that these patients can sometimes induce real illness by doing things like mainlining aquarium water. Not faking.
• Malingering: This is not usually thought of as a mental health disorder. Malingerers are seeking tangible material gains like analgesic drugs, a warm place to stay, avoiding jail or work, and those kinds of things. They invent symptoms and complaints to facilitate those benefits. By assigning the malingering label, you are saying that you are positive that the patient doesn't have any of the thousands of other possible medical diagnoses.  That ‘diagnosis’ stays in their medical record, affecting their future care, so you’d better be sure before you curse someone with that label.
• Real problem you incorrectly thought was being faked: The issue here is that people can spark your Johnston Sign sensor either through inventing problems where there are none, or through exaggerating real problems. Outright invention of complaints is actually more rare than you think.  People usually add complaints to their symptoms, overdramatize their problem, or otherwise exaggerate their real problem.  Sometimes they may not tell you their real problem, worrying that you may find it to be dumb and not help them.

The problem with separating all of these out is that it can't be done in a fast food restaurant, no matter how badass a medic you are. Separating malingering from real problems requires testing, imaging, and exams that are not available in the field. Even with those tools, experienced professionals with years of post-graduate medical education find it difficult to differentiate. 

The other problem is that even when you land on the malingering diagnosis, it is difficult to separate it into those who are inventing an imaginary problem and those that are exaggerating a real problem.  Invention is rare.  Exaggeration can be because patients don’t believe their problem will be seen as “serious enough,” that their problem is believable, their problem is a big problem but it isn’t medical, or even that their problem has been evaluated and the outcome did not meet the patient’s approval.  But there is a real problem there, even if it is exaggerated. 

My advice to you is to not worry about outing fakers.  You will never throw the bullshit flag and get a confession (I’ve tried, trust me - people just dig in).  The simplest solution is to assume there is a problem there. It may not be what they are complaining about. Search out and solve their problem, whatever it is.  It’s not like your pay will be docked for taking unnecessary patients to the ED, right?  What do you care - solve the issue.  If the issue is medical, I can start the process of getting the problem solved.  If the problem is that it is cold outside, I can solve that one too.  If the problem is that they want nurturing and sympathy, I can solve that one as well.  If they want a note to get out of work, I will write a note that they called 911. At minimum, knowing what their real problem is makes for a more accurate hand-off report.  "This is Fred, he's 40, and it's absolutely frigid outside so he wanted to go indoors…" 

When I suspect someone is faking or exaggerating a problem, I talk to them about it.  Bluntly and directly.  Something along the lines of: “I want you to understand that I am here to help you, no matter what problem you are having.  The way that you’re presenting your chest pain to me doesn’t match how I’ve usually seen chest pain in the past.  Whatever your issue is, I will help fix it.  I would like to hear you tell me about what is really bothering you, so I can help you…”  Once you make the promise to help with their problem, follow through with your vow. If they continue with chest pain, they continue with chest pain.  It isn’t a big deal – I can treat chest pain without ECG findings pretty easily. Make your treatment appropriate to your subjective and objective findings.

*Feel free to use the Johnston Sign as a descriptive tool to explain how a patient was presenting in a dramatic fashion, but use extreme caution considering it as a diagnostic tool. Never validated, never tested, unlikely to be…
**I should probably hyperlink to more information about each pathology, but you can search Wikipedia, WebMD, emedicine.com, or whatever your go-to medical source is as well as I can…

Children Aren't Just Little Adults

I just attended a lecture about pediatric prehospital care.  The first slide was what the first slide normally is in lectures like this: “Children aren’t just little adults.”

(From Larali21 via Wikimedia Commons, with permission)

The point that the presenter (who was very good, by the way) was trying to make is that there are differences between adults and children regarding vital signs, anatomy, physiology, communication abilities, etc.  It is a valid point to make.  But the point is banal.  Trite.  Elementary.

Athletes aren’t just fit adults.

Elderly patients aren’t just old adults.

Teens aren’t just young adults.

Women aren’t just homogametic adults.

Men aren’t just enpenised adults.

Asthmatics aren’t just reactive airway diseased adults.

Black people aren’t just pigmented adults.

Cardiac arrests aren’t just pulseless adults.

Quadriplegics aren’t just paralyzed adults.

The mentally disabled aren’t just intellectually challenged adults.

Psychiatric patients aren’t just ‘crazy’ adults.

There are very few patients who present completely the way that a textbook has told you to expect. Those that do fit into a textbook description probably do so through luck, and it is a temporary or superficial occurrence.  Every class or type of patient presents challenges and rewards.  Every patient could potentially present difficulties in communication, decision-making, examinations, and treatments. 

Different classes of patients have different organs, vital signs, risk factors, mortality rates, healing abilities, disease pathologies, customs, expectations, needs, desires, abilities, and so on.

As prehospital professionals, it is up to us to educate ourselves as to the differences commonly found in different types of patients, not just with children.  

My Field Training Mindset

I don’t remember specifically when I began to formally field train newly hired paramedics, but I’ve been doing it off and on for about ten years.  My trainees have become trainers, which is a pretty good way to be made to feel old.  

New grads on days when my knees hurt and I feel old.
(By Gideon Tsang via Wikimedia Commons)

I wasn’t as skilled an instructor when I began as I am now, and I don’t think that I am as good now as I will be in a few more years.  I try hard to pay attention to what works and what doesn’t, as well as think about how I teach in the field. 

There are two main points to think about when you are field training. 

The first is that a field trainer is like a test pilot in that they know how to recover from spins in a bunch of different airframes under different circumstances.  When I am training, I will allow the trainee get him/herself into a spin.  Not only that, but I will let that spin continue until the last recoverable moment.  My hope is that they learn to get their call out of the spin on their own.  I won’t intentionally put the call into a spin.

Mistakes are where people learn.  Mistakes are the best lessons.  There is a difference between a mistake and a safety issue, however.  I won’t let a trainee’s mistake affect the patient.  There is a line there – I will let the call get out of the trainee’s control, but not out of my control.  I try to not step in too soon or too late.

This came about because I hate it when I tell a trainee to start an IV and receive the reply that they were “just about to.”  If the patient gets all the way into the ED without an IV, then there is no “just about to.”  We can have then a frank discussion about the need for an IV on that kind of call.  On a call, I have to think about whether I would start that IV and whether that decision is a style issue, protocol issue, or life-altering issue.  I make sure life-altering issues are fixed before they affect the patient.  Protocol issues result in teaching after the call.  Style issues get discussed in a collegial manner after the call. 

I let a trainee draw up the wrong medication, but I stop them before they push it.  I let trainees immobilize patients that I wouldn’t.  I make sure CPR is done when it is needed. 

The point is to let a trainee run their own call however they like - all the way until it would harm the patient.  I allow the trainee to struggle.

The second training thought is that it is my job to change my teaching style, not the trainee’s job to change his/her learning style.  Some trainees respond to preschool teachers and some respond to drill instructors.  Some are visual learners, some prefer to read, and some prefer to listen.  It is up to the trainer to make the adjustment.

Name twenty non-traumatic causes of chest pain or drop and give me thirty!
(By Scott A. Thornbloom [Public domain], via Wikimedia Commons)

The trainee’s success is important, not the method of getting there.

So, do you think you are ready to field train?  It depends.  Are you a good enough medic to let the call spin out of control, grab the yoke, and restabilize everything at the last moment?  Are you insecure in your ability to quickly correct what is going wrong, resulting in you stepping in to the call too soon?  Can you push someone that needs to be pushed, support someone who needs supported, and explain concepts in different ways?