Pants on Fire, or Pants Under Fire

I remember a time when I was really new. I was in the field training program, new enough to still be stuck perma-attending, when my FI and I were sent to a drive-by shooting just outside of what would be considered downtown. We arrived to find a scared 17-year old male who had a story about being shot in the leg during a drive-by. “Gang members” drove up to him, asked who he claimed, and shot him when he said he loved his momma and Jesus. Shot for no reason. It was indeed a sad, sad commentary on modern life.

Officer, he was well dressed, looked Italian, in his early 40s, chubby...
By US Bureau of Prisons [Public domain], via Wikimedia Commons

He said he had been shot in the left calf, so we put him on the bed in the bus. I started to cut his jeans from the cuffs upward while my FI looked at me with an expression of disdain and frustrated anger and a police officer took the victim’s statement. (By the way, you could tell that I was new because I was actually cutting the patient’s jeans. Now I know that you only have to cut the bottom seam on a pair of jeans and the rest rips in a straight line really quickly.) As I was cutting, I had a brief thought that it was weird that there wasn’t a bullet hole in his jeans. But I knew that bullets did odd things from time to time. Maybe it was small caliber and didn’t make much of a hole so I missed it. Or something. One way or the other, I was way to busy to think discrepancies like that through.  

You see, back then I didn’t do a good job of investigating when my brain asked “What the F*ck.”

Anyhow, as I was cutting up the inside seam of the kid’s pant leg, I indeed came to the bullet hole in medial aspect of his inferior calf, right where the gastroc muscle ends and the lower leg narrows. This isn’t necessarily a life-threatening wound, assuming that there were no other findings. I made a mental note to check for expanding swelling and to ensure that the dude had pedal pulses. 

Out of habit, mostly, along with wanting to complete the job, I continued cutting the patient’s medial seam of his jean leg. I found a second wound at the superior part of his medial calf, just inferior to the knee. Wow. He didn’t even feel the second one. Adrenalin, huh?

I continued cutting while I absent mindedly pondered life and the human ability to not feel all pain. I came to a third bullet hole just superior to his knee. I still didn’t stop to investigate the larger, “What the F*ck” question. I suppose people get shot multiple times and only feel one wound. Or something. And what the hell were the gangsters using, some kind of machine gun or something? Dude had a line of wounds right up his leg.

While thinking about all of that, my hand continued to squeeze the trauma shears along his pant seam until I came to what I hoped was the last bullet hole. This one was at his left groin, just to the side of his sack. There was gunpowder stippling around the wound. 

Weird, I thought. How did they get that close to him during a drive by? (See – I told you I was new.)

My partner, who was not new, saw the wound and said, “You little liar!”

No, no, dude.  The other kind.  The pants on fire kind.
By LPLT (Own work) [CC-BY-SA-3.0], via Wikimedia Commons

The cop, who was in the back with us getting the patient’s statement, suspect information, and such, was apparently not new either. “Where is the gun? Where’d you put it, dammit! If a kid finds it, I'll hold you responsible!”

I am not a smart man. As proof of that statement, I offer the fact that I still didn’t know what was actually going on. The patient made a brief but valiant attempt to continue the gangster drive-by story, before it collapsed under the weight of evidence.

“I threw it into the bushes over by the swimming pool,” he finally admitted in a weak, defeated voice.

Now I finally began to catch on. Our patient was putting a handgun into his belt when it went off. The round barely missed his left nut before entering his thigh, exiting his thigh just above the knee, then reentering his leg at the calf, and coming out of his calf when it narrowed again. It stitched right down his leg and all he felt was the lower calf wound.  So he knew he needed help, but didn’t want to get in trouble. Thus, the imaginary gangster story. 

The three big lessons that I took from that call were that everybody lies (at least sometimes, a little), there is no substitute to thinking about findings that don’t match the story, and that there is no substitute for a complete exam. Even when you think it is a simple calf shooting call, the complete secondary exam finds all kinds of stuff.

ECG Filters, or My Least Educational Post Ever

The other day I was driving for the shift.  My partner and I responded to a high school for the report of syncope on the football field.  Practice was going on and one of the coaches had fainted.  In checking him out, my partner found out that coach was 55 years old, had felt weak and lightheaded, and thinks he just got overheated out in the sun.  His vital signs were normal and the coach was only complaining of residual weakness. 

We put him on the monitor.  My partner hit print (he apparently hadn’t read the Quick Six rant from a few weeks ago):

Dude was very worried about the inferior ST depression.  I  finished putting the precordial leads onto the patient.  The 12-lead that resulted, cut down for privacy of course:

Take a closer look at the two ECGs.  First, the third beat of Lead II in the print view:

Now, look at the second beat in Lead II from the 12-lead:

Do you see the difference?  The printed view has one and a half or two millimeters of ST depression.  In the 12-lead, though, the depression is gone.  Maybe there is half a millimeter of depression in the 12-lead, but there isn’t much.  What caused the difference?  (Hint: Look at the whole strips above, rather than the individual pictures.  The difference is spelled out.)

The signals collected by an ECG monitor are very small.  The heart’s electrical signal is around 1 millivolt, and many waveforms are much less than that.  So the ECG signal can be easily drowned out by other “noise.”  The extraneous signal can be from other muscular movements, nearby electrical equipment, nearby power lines, poor electrode-skin interface, and from equipment in the monitor itself.  The collected ECG signal must have the extra noise filtered out so that a clean picture of the heart’s electrical activity can be shown more clearly.

I need to take a minute here and explain that I am a little embarrassed.  You see, my plan for this week’s post was to explain how ECG filtering works.  So I spent all week researching the topic.  And failed.  Miserably.  I don’t understand the technical aspects of how filtering works on an ECG.  For those of you who are smarter than I am, or have a better technical background, there are several explanations on the internet.  Please take a few minutes to go check them out.  This one, for example.  Or this one.  Here is a powerpoint presentation in pdf form that tries to explain the topic.  All they did is confuse me and make me feel dumb.  So now I am sad.

Good friggin’ luck to you if you want to get into the specifics of signal filters.  If you can understand the topic (understand it, not just regurgitate it), then you are a better person than I.  If it is something that interests you, to read about log scales, low pass filters, Fourier Analysis, superposition, and phase distortion, well then knock your bad self out with the links above.

Here is what the average medic needs to know about ECG filtering: There is a difference between the print view and the 12-lead.  By the way, the screen on the monitor shows the print view.  The 12-lead is diagnostic.  You can make decisions based on a 12-lead.  It is the same view as on a 12-lead in the hospital.  The same thing cannot be said for the print view. 

Look at the bottom left of the printed ECG and the 12-lead above.  The print view is filtering at the 0.5-40 hertz level.  That is, there is more aggressive filtering going on to smooth the waveforms.  That filtering, though, can do weird things to the ST segments like, say, depress them by 2 millimeters.

The bottom left of the 12-lead shows the filtering is being performed at the 0.05-150 hertz level.  This is a diagnostic view.  It is going to result in more artifact, baseline wander, and general noise.  But it is also going to give you the accurate view of the patient’s heart’s electrical activity.  ST segments are accurate at this level of filtering.  In order to cut down on the noise in the ECG, we have to be very precise with electrode application, electrode location choice, vehicle movement, patient movement, and those kinds of things.  We have to make physical changes to improve the quality of the ECG, rather than relying on the monitor to filter out the noise for us. 

One way or the other, make sure that you are making decisions based on a diagnostic-level view of the patient’s ECG.  It would be pretty embarrassing to STEMI alert a patient based on falsely elevated print view ST segments. 

The print view can give you false positive and false negative findings. 

Seven Ss of Single Sedan Smashes

Your partner and you are sent to an MVA at I-6 south of U.S. 185.  When you arrive, you find a newish Ford Explorer that crashed into the right side wire barrier, taking out four or five of the metal posts.  The impact seems to have snagged the left front of the SUV and spun it to face oncoming traffic.  There is about a foot of left front damage, and sheet metal flexing means that the driver’s door won’t easily open.  The airbags deployed, but the windshield, steering wheel, and dash are all intact.  None of the damage extends into the passenger compartment.

The only occupant is the 60-year old female driver.  She was seatbelted and has no complaints.  Your detailed physical examination yields no indication of injury.  The driver is oriented, with decision-making capacity, but she doesn’t remember what caused the accident.  She states that she remembers leaving lunch with a friend and remembers facing the wrong way on the highway with steam coming out of her crunched up hood.  There is nothing in between those two memories, though.

Why did she crash?

There are “Seven Reasons for Single Sedan Smashes” that you need to know.  In reality, however, there are Ten Reasons for Single Vehicle Crashes.  (The ‘seven’ is alliteration with sedan and smash. We’re really talking about the ten reasons that single vehicle MVAs occur, but all the S-words makes it sound all snazzy.)  People don’t bend their vehicles into an immobile object very often.  Most crashes involve two vehicles trying to occupy the same space at the same time.  People expect the other driver to wait, or to not stop, or whatever, and it causes a crash.  I mean, you’ve met your average patient, right?  Or the jackhole in front of you during rush hour?  Consider that they are [reportedly] in control of two tons of vehicle at seventy miles an hour.  It shocks me that we aren’t running more crashes, if I’m being honest. 

But single car crashes are slightly weird.  People really shouldn’t be driving into trees.  Trees don’t suddenly jump into their path. 

Dude! Why did you crash? Are you hypoglycemic?!?
(By Bo Nash [CC-BY-SA-2.0], via Wikimedia Commons)

The ten reasons for single vehicle MVAs are seizure, syncope, sudden cardiac arrest, stroke, sugar, sleep, sauce, suicide, shit happens, and stupidity.  Pretty much every reason for a single vehicle grinder is contained in these ten reasons.  The trick is to understand that #10 (stupidity) is the diagnosis of exclusion.  You need to rule out, as much as you can, the other reasons for bending a vehicle around an immobile object before you roll your eyes at your patient’s lack of driving ability. 

In more detail…

1. Seizure – People have seizures.  Sometimes those seizures can occur when they are driving.  This is especially true for first-time seizures because people don’t know what that “orange smell” portends.  So they seize and the car goes where it will.  Hopefully you can identify a postictal patient enough to be suspicious of the seizure being a potential cause of the accident. 

2. Syncope – This is pretty much a big-tent kind of point.  There are hundreds of events and conditions that can cause syncope.  For our purposes, though, we are worried about arrhythmias, vagal episodes, situational syncope, occult bleeding resulting in hypotension, and such things.  These are the same big-deal reasons for syncope that you work up when you run a fainting patient.  Prodromal symptoms should be part of the pre-crash story.

3. Sudden Cardiac Arrest – The most common reason for me to suspect sudden arrest is finding a dead guy in a crash that really shouldn’t have killed him.  The vehicle has a bent license plate, but there is a corpse in the driver’s seat without a scratch on him.  In these cases, even though it is a “trauma” call, I work the arrest like a medical arrest.  If you suspect that trauma didn’t cause the arrest, then a medical event probably did.  Work the medical arrest in those cases.

4. Stroke – It sucks to have a stroke, but it sucks even more to have one happen at highway speeds. 

5. Sugar – It sucks to be hypoglycemic, but it sucks even more to have it happen at highway speeds.  By the way, the crash won’t correct their blood sugar levels.  Their sugar will still be low, they will be tachy and diaphoretic, and they will still have all the other signs of hypoglycemia after the crash. 

6. Sleep – People fall asleep behind the wheel.  They take long trips on boring highways at night.  They also take an Ambien and misjudge how long until it takes effect.  Whatever the cause, sleep can cause a crash.  This is more likely at night, of course, or if the driver describes a fatiguing trip (long haul trucker, maybe, or a long ass drive in general).

7. Sauce – I am talking about alcohol intoxication of course, but you should also think about any other consciousness-altering substance or medication.  There are a bunch of analgesics, sedative/hypnotics, anxiolytics, and miscellaneous psychiatric medications that affect driving ability.  But for the most part, alcohol is the big one.  Single car crashes result in DUIs all the time, right?  Drunk people drive into stuff.  But you should be able to pick up on the signs of acute intoxication.

8. Suicide – I once saw a guy that unbuckled his seatbelt, balanced a tire iron on the steering wheel pointed at his chest, and floored it into a concrete wall.  Suicide.  (That guy made a poor choice, based on the fact that his last words were to me when I walked up to his window: “This hurts man.”)  Other people steer into oncoming traffic*.  Thelma and Louise drove off a cliff.  Suicide in a car happens.

9. Shit Happens – Sometimes the insurance term “act of god” makes sense.  Consider the family that had a i-beam bridge girder fall on their car without warning.  Or a rock that falls out of the truck in front of a dude, who then stops the rock entirely too suddenly.  Freak accidents look like freak accidents, though.  Freak accidents don’t look like a person drove into the guardrail a little.  Freak accidents kind of scare you about your own mortality.

10. Stupid – See my point above about your average patient being in sort-of-control of two tons of mobile steel.  This is the diagnosis of exclusion, but it is probably the most common reason for single car MVAs.  People text and drive.  They get CDs off the passenger floor while driving (maybe not nowadays, but when I started in EMS they did that kind of thing).  They put on make up and eat greasy burgers while driving in the snow.  Hell, admit it – you do these things, probably while driving emergently.  I once was off-duty and cruising at 70 miles per hour on a dry highway when I found an elk in my headlights.  My gentle course correction to avoid smashing the stupid thing caused me to do a 360.  On dry highway.  At 70.  Thankfully I didn’t roll it, but I had to rock when I got out of my truck to break the suction.  Stupid things happen and cause single car crashes. 

I saw a teenager who crashed into a tree when avoiding a raccoon. Which is good, because I love this picture and it gives me the excuse to use it. Look at that bastard in front. It just puts a smile on my face...
(Photo courtesy Jeremy Johnson, Meddling with Nature)

Just make sure one of the other nine didn’t cause the crash before you blame it on “Stupid.”  The same goes for the shit happens point.  If you find one of the other weird reasons, you get to look like a badass.  Another problem is that many of the causes will have presentations that mimic head injury or other traumatic injury.  It is pretty difficult to differentiate whether a seizure caused the crash or was the result of the crash, for example.  Just do your best. 

Remember to think through the ten reasons for single car crashes.

Oh, and the lady in the introductory scenario?  I couldn’t figure out what caused the crash.  So I picked at it.  I wouldn’t let it go.  After digging and digging, she told me that she was narcoleptic.  But she hadn’t had an episode in years.  Granted, she ran out of her Provigil two or three days ago, but that shouldn’t mean anything.  Right?

*Not a single car crash then, I know.  Just roll with the point I’m trying to make.

I Hate the Term “Sober And Competent” Part II

In Part I, I tried to explain why I think the term “soberandcompetent” is not a useful one. It is more important to assess whether a patient has decision-making capacity.  Capacity entails the ability to absorb the medical information, synthesize it into information that is meaningful, and make a decision based on the new data.  Simply, does the patient understand and appreciate what is going on and communicate their choice?

I hate to say this, but in the end it is all a grey area.  You are going to have to make a judgment call.  There is not a list of approved questions that all need to be answered quickly and correctly for a patient to have capacity.  It would make your job easier if such a list existed, but your job is hard.  EMS providers must be able to describe the reasons that they think the patient has or lacks decision-making capacity.

I try to answer that question on two levels.  First are the general orientation questions. For someone to have decision-making capacity, they should be generally oriented:

• What day of the week is it? (Not date.  I hate when people ask the date of patients.  Shit, I only know the friggin’ date plus/minus two days…)
• Where are you right now? (What's a correct answer? Country? State? City? In an ambulance? Do they have to know the intersection?)
• What is your name? (How do you know what the right answer is?  I try to only ask questions that I know the answer to...)

I add other questions that help assess whether the patient’s brain is working as it should.  Competent decision makers should be able to handle simple questions. For example:

• How many quarters are in a dollar-fifty?
• Who is the president?
• Who plays quarterback for the Broncos? (Change the team name to one important to your city. I find "Dunno, I don't like football" works. They translated Bronco to football, which is a correct answer.)
• Name a sports team. Any sports team.
• What holiday did we just have? (Be careful: This is unhelpful in months without important holidays and is kind of a Eurocentric question.  I mean, if the patient's answer is "Maha Shivaratri" are you going to call bullshit?)

These kinds of questions show more than whether a patient can perform simple math or regurgitate a politician’s name.  They require translation from one level of thought to another.  The patient has to translate dollars to quarters.  The patient has to translate Broncos to Manning, or sport to baseball to New York Yankees.  Most importantly, they are all questions that anyone can answer.  My grandmother hates sports, but can name the Yankees.

Everyone can name the New York Yankees and the Regina Butter Churners Hockey Club, right?
(By Knipple23 (CC-BY-SA-3.0), via Wikimedia Commons)

It isn’t an interrogation.  I tell people flat out that I need to check how well their brain is working and ask the questions with a smile.  Their answers may lead to jokes or other conversation. 

People should be able to answer simple questions like this without too much trouble.  I give folks wiggle room, if they have good reason.  Everyone should know that six quarters make up a buck-fifty, but not all nursing home denizens know the day of the week.  If you don’t have a job, or other reason to know what day it is, who cares?  If someone names the president-elect rather than the president in December 2016, I'm not going to chicken-wing them off to the hospital.  I base my capacity decision as to how much their answers make sense.  Grey areas, baby!

All of this is a grey area (all of EMS is one big grey fog bank), but if a patient doesn’t know that two days ago was Christmas then I have to question their decision making capacity (even if they are not observant Christians).  If they say that there are four quarters in a dollar-fifty, or if they think entirely too hard to come up with six quarters, then I have to question whether they can understand and appreciate what is going on.

If they are just uncooperative asses and refuse to answer the questions, I have to question whether they can understand and appreciate what is going on.

If they answer those kinds of questions well, I need to move to the second level of decision-making assessment.  This level of capacity-assessing questions involve the decision itself:

• Tell me in your own words what I think is wrong with you. (This is checking whether they can take the information that you gave them, absorb it, and give it back to you in a way that makes sense. I don't care whether they agree with my opinion; I care whether they heard my opinion.)
• What is my opinion of what might happen if you don’t go to the hospital. (I don't care what they think.  I care that they have heard my worst fear.)
• What do you think will happen to you at the hospital?  If you stay home? (With this, I am just curious about what they are thinking.)
• Help me understand why you want to stay home. (Just ask the question straight out.)

A patient doesn’t have to agree with me as to what is wrong, or about what may happen.  They have to be able to show that they absorbed the information accurately and can communicate their decision.

From that point, after I have assessed the patient’s level of orientation and whether the patient can understand what is going on and make a reasoned choice about their medical care, I need to make a decision of my own: Does this patient have the capacity to make a decision about their care?  If I think they do, I need to be an advocate for their position. 

Remember, it is a grey area.  If I have doubts, the patient probably doesn’t have the capacity to safely make decisions for themselves.  See what your partner thinks.  See what the cop on scene thinks.  Their opinions can be helpful, especially if they can explain them.  If worse comes to worse, I can contact base and get a second opinion from the physician that answers the phone.

The kinds of questions listed above are helpful in another way.  The answers to the questions help me to explain why I think the patient possesses capacity.  I will have to do it on the patient care report, and may have to do it on a biophone report too.  I never say that the patient is “soberandcompetent.”  That term is unhelpful.  People respond better when I state that “…I believe the patient has decision making capacity…”  If I am asked why I think that, I can explain my decision because I asked a whole bunch of questions.  I can explain because I explored the specifics of the patient’s level of orientation and their decision making process.  I know that they can absorb accurate information and make decisions based on the information.  And I can describe that process. 

So, does the patient in Part 1 have decision-making capacity?  I don’t think so.  Hallucinating is not a sign of clear thinking.  The patient didn’t make the decision, the cat did.  So the invisible cat can stay at home, but the patient would be coming with me to the hospital.