Calling All Medical Pros again, this time for defibrillators

Okay, this might sound simplistic, but why is she getting shocked? Is she young, old? Is this a trauma? Does she have a history of cardiac disease?
Young normally healthy people, don't often get defibed. If her heart stops, goes flat line, drugs would be used not a defibrillator, if she has an arrhythmia, yes defibrilation would be called for, but if she is young , why would she have a dysrythmia? Drugs? Trauma to the chest? A little more information please.

Here is a quick rundown:

1. If a person is not responding, we do the ABCs first, after making sure we are safe. So, airway, breathing, circulation - does the person have a pulse.
2. For the most part, what you will be shocking is a person without a pulse. Certainly, unless this is a medical book that is what you will want.
3. So, no pulse. Now, is this a shockable rhythm. If the heart is dead (not beating at all, shocking will do nothing). So, we start CPR while someone else gets the AED.
4. For this to work, we need to exposed the chest of the victim, and also not have the victim lying, say, in a pool of water.
5. No paddles, stick on paddles. The idea is for the current to go across the heart. This means that the sick on electrodes have the heart between them. Right upper and left lateral chest. The electrodes have pictures on them demonstrating this. We can also put one of the electrodes across the back.
6. If this person has a shockable rhythm, they are more likely to survive. So we stop CPR and analyse the rhythm as soon as we can.
7. In the field, the device will usually take it from there. All that has to be done is check that the victim is not in contact with anyone else, and then push the SHOCK button.
8. In your situation, you will likely want the patient to be in VENTRICULAR FIBRILLATION, or VF. If you were to look at the heart when it is in this state, you would see what looks like a squirming bag of worms. Ventricular tachycardia means that it is beating in an organized fashion, but so fast, that there is not enough time for the heart to fill. In both cases there is no forward flow of blood.
There are two types of defibrillators, Monophasic and Biphasic. Most are Biphasic nowadays. The current they would use is 200J. If Mono, 360J. But, as I said, you do not need to select this, mostly.
9. So, "STOP CPR AND ANALYSE" "ANALYSING" "DELIVER SHOCK" The important mantra we often hear before shocking is: "EVERYBODY CLEAR. I'M CLEAR, YOU"RE CLEAR, WE'RE ALL CLEAR. SHOCKING NOW"
10 Once the shock is done, we start CPR AT ONCE. In the past, we used to wait to see if the heart was beating. Now we know that even if it is, it is beating weakly. So, we give chest compressions.
11. What makes someone survive this type of situation is GOOD CPR, given EARLY, followed by SHOCKS. The CHEST COMPRESSIONS are what is most important.
12. In the ER, we do the same. Same currents for this type of situation. We are not monkeying around, as we may if the person is conscious with a pulse. Defibrillation hurts. A lot. If the person is in a different rhythm and awake, we need to sedate them first. If they're dead, we don't care, we need to shock them, and fast.
13. Paddles? NO. In the OR, we use much smaller currents, and small paddles to shock the heart directly, if the chest is open. In the field, I would say never anymore, unless we had really old equipment. In the ER we do sometimes use the paddles if we have a really obese person, or one with over-inflated lungs (emphyesema). What we do in that situation is to compress the chest as much as possible between the paddles to maximize current delivery.

The heart rate after shocking is what it is. Because we also give dugs like Epinephrine and Atropine during a resuscitation, it will often end up being more rapid initially than we would like, after a very shot period of slow beats. BRADYCARDIA is slow, and below 60 beats a minute. TACHYCARDIA is fast, and over 100.

So: "WE HAVE A RHYTHM - PULSE CHECK" "NO PULSE" "RESUME CPR" .... "PULSE CHECK" I HAVE A PULSE" "PULSE 110" "PULSE AGREES WITH MONITOR" "CHECK BP"

That sort of thing. Remember, you can have electrical activity on the monitor, with no output. We speak of ELECTROMECHANICAL COUPLING, but you won't hear that so much.

Next, in a REAL cardiac arrest, we will start cooling of the patient immediately after successful resuscitation, as that improves survival and outcomes.

Finally, remember, that pitifully few people who arrest in the field ever get to leave hospital, despite medical advances. It is not a common thing.

HTH
CB

Defibrillators do NOT shock people back to life. If the heart isn't beating shocking won't do shit. Defib means the heart is beating erratically and the shock is supposed to restore a normal rhythm.

Shadow_Ferret said:

Defibrillators do NOT shock people back to life. If the heart isn't beating shocking won't do shit. Defib means the heart is beating erratically and the shock is supposed to restore a normal rhythm.

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QFT-

No heart beat-NO SHOCK - DRUGS
Funky heart beat- SHOCK

So in your scenario- falling off a house-it would be very unlikely your MC would have cardiac issues requiring shocking- Broken bones, head injury, internal injuries, you betcha- heart stopping or funky rhythm? Not so much- BUT it is fantasy- so-

CoolBlue said:

Here is a quick rundown:

1. If a person is not responding, we do the ABCs first, after making sure we are safe. So, airway, breathing, circulation - does the person have a pulse.
2. For the most part, what you will be shocking is a person without a pulse. Certainly, unless this is a medical book that is what you will want.
3. So, no pulse. Now, is this a shockable rhythm. If the heart is dead (not beating at all, shocking will do nothing). So, we start CPR while someone else gets the AED.
4. For this to work, we need to exposed the chest of the victim, and also not have the victim lying, say, in a pool of water.
5. No paddles, stick on paddles. The idea is for the current to go across the heart. This means that the sick on electrodes have the heart between them. Right upper and left lateral chest. The electrodes have pictures on them demonstrating this. We can also put one of the electrodes across the back.
6. If this person has a shockable rhythm, they are more likely to survive. So we stop CPR and analyse the rhythm as soon as we can.
7. In the field, the device will usually take it from there. All that has to be done is check that the victim is not in contact with anyone else, and then push the SHOCK button.
8. In your situation, you will likely want the patient to be in VENTRICULAR FIBRILLATION, or VF. If you were to look at the heart when it is in this state, you would see what looks like a squirming bag of worms. Ventricular tachycardia means that it is beating in an organized fashion, but so fast, that there is not enough time for the heart to fill. In both cases there is no forward flow of blood.
There are two types of defibrillators, Monophasic and Biphasic. Most are Biphasic nowadays. The current they would use is 200J. If Mono, 360J. But, as I said, you do not need to select this, mostly.
9. So, "STOP CPR AND ANALYSE" "ANALYSING" "DELIVER SHOCK" The important mantra we often hear before shocking is: "EVERYBODY CLEAR. I'M CLEAR, YOU"RE CLEAR, WE'RE ALL CLEAR. SHOCKING NOW"

[...]

HTH
CB

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What CoolBlue has described here is the use of an AED, but paramedics don't use AEDs. We use manual defibrillators.

That means:

Yes, paddles. This is the Lifepak 15, which is my service's current defibrillator/cardiac monitor combo of choice. This device is the newest available and the current standard for ALS, so not exactly outdated. It has an AED mode, so electrode patches are available, but in manual mode we use these. (There are ambulance companies, particularly where ASL and BLS might use the same truck, that only use electrode patches, though.)

The machine doesn't analyze the rhythm for you, you have to do it yourself and select your settings accordingly. If possible you want a 12-lead EKG for this, but you can have the paddles act as leads to give you a rhythm, too.

It doesn't sound out what to do. AEDs are designed for people with no training, so they prompt you to press shock, to do CPR etc. A paramedic has to know this anyway, so the only thing a manual defibrillator might do is alert you to a rhythm change.

What energy setting you use is device-specific, so you want to check the operating manual. Most commonly you'll find 150 or 200J. (We generally start with 200J and stay there.)

Regarding sounding out: contrary to what you might see on TV paramedics don't really sound out what they're doing. I don't shout "clear" when I shock people, I just make sure nobody's touching my patient and then I do it. "I'm clear, you're clear etc." is mostly for rookies so they don't forget and accidentally hurt someone. (The manual says everybody should do it, but nobody does.) Chances are there's only one other person with any clue about what's going on anyway and that's my partner. And he knows what to do.

As for the rhythm post-shock, that varies. What you want is a normal sinus rhythm and sometimes you even get that. But one thing many patients do after ROSC (return of spontaneous circulation) has occurred is go right back into arrest.

But, like sheadakota said, while this scenario might result in a traumatic arrest, chances are your character's got other problems.

There are situations where falling off a house could result in CV trauma, but the more likely scenario is that the CV issue caused the blackout and the resulting fall off the roof. Ventricular tachycardia or an arrhythmia can easily cause someone to blackout and fall.

Also, it's not as simple as no HR = drugs, irregular = shock. There's a lot of people walking around with abnormal rhythms, particularly atrial fib. So long as they have a decent POx and a reasonable HR you're not going to shock them.

The belief that shock is used to "restart" the heart comes from all the more recent medical shows, like ER, etc, where they incorrectly show it that way.

Interestingly enough, if you go back to the old 1970's TV show "Emergency", about Paramedics, they use the correct procedures from when to defib a patient.

The actual protocols from the 1970's may be a bit outdated now, but if you watch the show you'll see them put on leads, use drugs correctly, and use defibs to convert the rythm to a normal rythm. They never do the "He's flatlined so use the defib" thing.

Is your character supposed to be dead or comatose? Those are different.

Regarding hearts, pulses and defibrillators: No pulse means there is no meaningful blood flow, but not necessarily there's no heartbeat. A defibrillator doesn't start anything, it stops. When a person is in cardiac arrest there's four main scenarios. The first is called ventricular tachycardia or v-tach. This means there is a rhythmic heartbeat, but so fast no blood is moved. Second is ventricular fibrillation or v-fib. This is a very rapid and erratic heartbeat.
Most recent cardiac arrests are these two (v-fib primarily), with v-tach often turning into v-fib along the way. These are also the two rhythms that are shockable. The name's kind of telling you: the problem is fibrillation, the solution is defibrillation. The idea of a shock is to stop the erratically beating heart entirely in the hope that it'll resume beating in a normal rhythm. Think of it like pulling the plug on a frozen computer. You shut the whole thing down so the rebooting process fixes the issue.

If the heart has already stopped beating on its own, this is not going to work, obviously. So if there really is no heartbeat, you can't shock. Those are the other two scenarios. There's PEA, short for pulseless electrical activity. This means there is something going on on the EKG, the occasional blip and spike, but no actual rhythm. Lastly there's asystole. This is the famous flatline. Nothing's happening anymore, the electrical conduction system of the heart is dead. A defibrillator won't help, but there are drugs. The main one is epinephrine, the second vasopressin. There used to be atropine as well, but it's no longer recommended. However, the survival rate for people with PEA or asystole is dismal. Most people in v-fib already don't make it and the prognosis for no shockable rhythm is much worse. (Cardiac arrests tend to progress from v-tach/v-fib to PEA and asystole, which is why early intervention is critical.)

Patients that do get resuscitated don't come to, though. The movies show a successful resuscitation with the patient only coughing a few times (generally after receiving CPR only, which doesn't resuscitate anything) and being perfectly fine right after. A real-life resuscitated patient is a) generally still unresponsive, b) prone to go back into arrest and c) still in dire need of medical attention since something had to have caused the arrest in the first place. It's now common procedure to induce protective hypothermia to prevent further tissue damage.

Sometimes a patient will regain consciousness, though. They'll be in very bad shape. What they often do is gag/vomit. They might also try and fight the endotracheal tube. (An unresponsive patient should be intubated and be given oxygen with a bag valve mask while CPR is ongoing.) They're not going to sit up, talk or gaze adoringly into their rescuer's eyes and start kissing passionately after professing their undying love. Regaining consciousness right after resuscitation is very rare and in a novel eye-roll-worthy.

A note on CPR, no scenario has "just CPR" as a treatment option. CPR is a stop-gap procedure to keep oxygenated blood circulating and thus prevent organ damage until actual treatment options (drugs and/or defib) arrive. It's not a treatment itself. When the patient has a pulse you should not be doing chest compressions.

This has been your friendly neighborhood medic's guide to the wonderful world of cardiopulmonary arrest. I hope this helps you to work out what you need and I didn't end up confusing you even more.

asroc said:

What CoolBlue has described here is the use of an AED, but paramedics don't use AEDs. We use manual defibrillators.

That means:

Yes, paddles.

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Well, colour me different. Not surprising that there are differences, though. Different services, different countries (I have defibbed pts in 3, over the years), that sort of thing. To the best of my knowledge (I do not currently manage EMS services), where I work, all of our services have automated functions on their defibrillators. Sometimes they are used. Sometimes not. Our paramedics have patches.

And yes, we call it out. Every time. Almost. But this is in the ER. Perhaps not so distinctly, but still. That could be related to the fact that we are a teaching facility. So we have students at every code we run in the ER. We do train EMS staff to do this as well. We can learn from the airlines. By using simple checks and not referring to those with less learning as rookies, their safety rate has improved immensely.

Paddles, you say? What is nice about the patches, is that the transfer goes better between EMS and ER, as all we do is change the leads. (YES, they are matched between our services!) And they make defibrillation safer.

BTW, the LifePak15 can be operated in AED mode, when it WOULD analyse and call out the defib for you.

But I think the OP wanted an idea, so there was no glaring error in the approach, not necessarily how any given service is trained to do things.

So, the character fell and is not responding. Does she have a pulse? If not, we start CPR, and get help. Why did she fall? If she suffered a cardiac arrest (perhaps she touched an electric wire), she is most likely in ventricular fibrillation. If we get to her soon enough, perform adequate chest compressions while getting the defibrillator to her, she actually has a fairly good chance of a good outcome. If she has a good strong pulse, plus/minus breathing, she likely fell and then suffered a head injury. No drugs, no paddles, cooling and surgery is all that might save her.

CPR is there to get oxygen to the cells. Brain for obvious reasons, and then the other vital organs - heart, kidneys and liver. We first support the circulation (ABC has moved to CAB in adults), then the airway and breathing. Shocking is there to take a bunch of heart cells that are not all contracting as they should because the electrical system of the heart has taken a vacation, and stopping them, so they can "take it from the top", so to speak. No electrical activity, no shock. Electrical activity in the face of cardiac chaos? Shock. Electrical activity with differing levels of organisation? Not so simple. So, stick to the simple scenarios, if you want to remain sane and believable.

If you want your character to survive well, and need defibrillation, use an easily reversible thing with no underlying disease. Like an electric shock. A blow to the chest that does no other harm. Like a hockey puck. Or an undelying disorder of the heart that can be fixed if it is diagnosed before it is too late. See, for example, Wolf Parkinson White syndrome.

Most people who need defibrillation are sick. And they die. Even if we get them to the hospital. The "successful" defibrillation in the field or ED is mostly still followed by a funeral. Sad, but true.

Phew, quite the thread! Did we tell the OP that there will be an exam on this later?

HTH
CB

CoolBlue said:

Well, colour me different. Not surprising that there are differences, though. Different services, different countries (I have defibbed pts in 3, over the years), that sort of thing. To the best of my knowledge (I do not currently manage EMS services), where I work, all of our services have automated functions on their defibrillators. Sometimes they are used. Sometimes not. Our paramedics have patches.

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I'm not sure what you're arguing. AEDs have their place in EMS, but the OP asked what happens when paramedics defibrillate someone. Since the OP is based in the US I'm assuming she's using "paramedic" in the US-American sense, referring exclusively to ALS providers. (I know in Canada the term refers to all responder levels, but not in the US.)
And an ALS response means manual defibrillation. You described AED use, but under normal circumstances you will not see American paramedics use AEDs. The standard is manual defibrillation in accordance with AHA/ILCOR ACSL guidelines, which I know for a fact level II/Advanced Care Paramedics in Canada also use, at least in Toronto. Manual defibrillation is superior to automated defibrillation everywhere, after all.

CoolBlue said:

Paddles, you say? What is nice about the patches, is that the transfer goes better between EMS and ER, as all we do is change the leads. (YES, they are matched between our services!)

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Never been anyplace where that wasn't the case for both patches and paddles. Most American services use paddles for manual defibrillation (faster, less wasteful), so for the OP's scenario that's what she's most likely to see.

CoolBlue said:

BTW, the LifePak15 can be operated in AED mode, when it WOULD analyse and call out the defib for you.

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Yes, it has an AED mode, which is why I specifically mentioned it in my post. The point is, paramedics do not use it. What you described in your post is not what would happen in the OP's scenario.

suestrong315 said:

Okay, so now Hopefully I can get this going in the way it needs to be:

MC loses consciousness. her heart slows down, she's entering shock, she's basically dying. If she loses her pulse then the medics should jab her one with epinephrine and perform chest compressions while intubating her?

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If she's in shock her heart would speed up, not slow down. If she loses consciousness because she's losing blood she's on the door of death and needs an IV and a transfusion fast. If it's because of a head injury, that's a whole other set of problems.

Epinephrine comes after a round of CPR (and it goes in through the IV). I really wish I was able to intubate someone while doing chest compressions, but for that you really need two people. If we have a work-intensive patient like that we'll often get a police officer or firefighter to drive the ambulance while we both work in the back.

suestrong315 said:

ok let's just throw the scenario out there:

you're a medic who gets called to someone falling off a house.
- When you get there, she's unconscious, but still breathing. What do you do?

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Do a rapid assessment while stabilizing the cervial spine and backboarding her, intubate, give high-flow oxygen, load and go, start two large-bore IVs, control any external bleeding, start an EKG, monitor vitals (EKG, CO[SUB]2[/SUB], O[SUB]2[/SUB], blood pressure), give saline bolus if BP drops. (If this is set in a rural area they ought to seriously consider a helicopter.)

suestrong315 said:

- At some point during prepping her for the ride to the ER, she her heart stops beating, what do you do?

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CPR. Assuming she's an adult, 1 mg epinephrine or 40 units of vasopressin though the IV, repeat every three minutes or so. Get my medical control on the line, if only for the option of having the patient pronounced.
(Note: Hardly anyone goes from an okay heartbeat straight to none. Generally asystole happens by way of v-tach and/or v-fib. You can shock those.)

suestrong315 said:

- Once she's stable enough to be moved, what could happen while on the way to the hospital apart from her just dying from internal injuries?

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EMS transports unstable patients and this one won't be stable until all the way at the hospital. So this would most likely happen when already en route. An injury like that is what we call a scoop-and-run. You spend as little time as possible on scene.

You want something besides cardiac arrest happen to her? What has she ever done to you? (If she's dying from internal injuries, this is probably what it would look like anyway.)

suestrong315 said:

lol no I just want cardiac arrest, I was just trying to avoid "what else could go wrong?' "death from internal injuries"

Asroc you've been ultimately epic. <3 you.

REPS TO EVERYONE!!

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There are three types of Cardiac Arrest.

1) Asystole. This is the classic "Flatline" that you see in the movies. In all honesty there is very little that can be done about this. It is only present when there is no electrical activity in the heart at all. The treatment is CPR, and hope.

2) VF/Pulseless VT. Ventricular Fibrillation is where all the cells in the heart are still compressing, but not at the same time. You get a random jagged line. Ventricular Tachicardia is big regular spikes. It can sometimes have a pulse, and sometimes not. These two are treated the same because they are the only rhythms that are shockable.

3) PEA. Pulseless Electrical Activity looks normal on the EKG, but there is no pulse. There is no point in shocking this because the electrical activity is normal, the heart is trying to beat, but something is stopping it.

1 tends to happen when 2 or 3 have been left untreated for a while as they both deteriorate into it eventually. 2 occurs after an electrical conduction problem such as a myocardial infarction on a conduction pathway. Technically this can be caused by a direct blow at the exact time in the electrical cycle, but it is incredibly unlikely. 3 tends to have a specific cause, and is the most common form of arrest rhythm after trauma. There are 8 common causes, if you are interested I'll list them and their treatment.

Basically what I'm trying to say is that if you want your character to have an arrest after a traumatic incident then you won't be shocking them to fix it.