# ASA & Nitro



## mikie (Jan 29, 2008)

For us basics in the area, we can administer 7 drugs (O2 is included).  For chest pain, we have nitro spray and 'baby' asprin (4 tabs. for 324 mg)

My question is when to chose nitro or ASA and vise versa.

(per our protocol):

*Nitroglycerin*


> *Indication:* Chest pain w/ Systolic > 100. *Contraindications*: Systolic < 100, altered LOC, Pt. Already taken max dose, erectile meds. within 48-72 hours)



*Baby Aspirin (Chewable)*


> *Indication:* Chest pain, suspected angina or MI.  *Contraindication:* Allergic to aspirin, active ulcer, asthma <30 y/o).



So other than if a contraindication is a problem, when would you use one over the other?

Thanks!


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## JPINFV (Jan 29, 2008)

No offense, but if you don't know what your medicantions do, you shouldn't be administering them. If you knew what they did (acetylsalicylic acid is an anti-coaglent whereas nitro is a vassal dialater), then you probably wouldn't be asking this question. Those drugs are not either/or.


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## daedalus (Jan 29, 2008)

When you suspect AMI or unstable angina, you can use "MONA" (morphine, oxygen, nitro, ASA)

These  drugs can safely be used with each other. In most cases, ALS must provide the morphine administration, but some BLS crews may be able to provide the other three drugs. 

The above poster is correct, you should try and learn more about the drugs you are giving before you give them. Now in days with google and wikipedia, there really is no excuse.


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## mikie (Jan 29, 2008)

I know what the drugs do, I was just wondering the timing-but after reading into my local protocol it seems we would use both


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## disassociative (Jan 29, 2008)

JPINFV said:


> No offense, but if you don't know what your medicantions do, you shouldn't be administering them. If you knew what they did (acetylsalicylic acid is an anti-coaglent whereas nitro is a vassal dialater), then you probably wouldn't be asking this question. Those drugs are not either/or.



Sorry, just a pet-peave of mine; it is "anti-coagulant" and Vaso-dilator

Also, let's be a tad more specific..

Aspirin is a thrombolytic that reduces overall mortality of AMI, reduces additional infarct, strokes and furthermore blocks formation of Thromboxane A2, which in turn causes platelets to aggregate and arteries to *constrict*

Contraindications are: Acute ulcer disease, GI or other bleeding disorders,
patients experiencing asthma attacks, hypersensitivity to ASA, or ASA prior to arrival.

Doses higher than recommended can interfere with Prostacyclin production. 

while the exact mechanism of action is unknown, we do know that ASA inhibits prostaglandin sythesis, producing analgesia, anti-inflammatory, and
anti-pyretic effects, and irreversiby inhibits platelet aggregation (salicylate).

Metabolism: gut and plasma(aspirin), liver(salicylate) CYP 450 is currently unnown. Its excretion is usually through urine, of course with a half-life of 0.25h(aspirin), 2-6h (salicylate); though the half-life is dose dependent and the amount excreted is pH-dependent.

Now, Nitroglycerin(NTG) is a rapid smooth-muscle relaxant that causes decreased cardiac work. NTG dilates BOTH arterial and venous vessels and causes venous pooling of blood. I repeat, causes venous pooling of blood.
NTG also causes vaso-dilation of the coronary arteries *thus, increasing perfusion(keyword) of ischaemic myocardium(bad ju ju).*

While pain relief ocurs within two minutes, therapeutic effects can be observed up to 30 minutes later. 


*Indications: MUST HAVE ALL OF THE FOLLOWING S/S*

Exhibits signs and symptoms of chest pain 
Has physician prescribed sublingual tablets or spray AND
has specific authorization from medical direction unless standing orders exist.

*Contraindications(AND THIS IS IMPORTANT)*

Hypotension or *blood pressure below 100 mmHg systolic*, I repeat:

*Hypotension or blood pressure below 100 mmHg systolic*

Head Injury or increased ICP
Hypovolemia, severe bradycardia or tachycardia

*Recent use within 24 hours of Viagra*

*Infants and Children(If you want to know a quick way to lose your license, this is it.)*

Patient has already met maximum prescribed dose prior to EMT arrival.

NTG may induce headaches from vasodilation of cerebral vessels.

Pharmacology:

Metabolism: liver, erythrocytes(red blood cells), vascular walls
half-life is 1-3 min, 40 min(metabolites)
half-life: 1-3min, 40min (metabolites)

Mechanism of Action:

stimulates cyclic GMP production, resulting in vascular smooth muscle relaxation.

I think that is enough for now.


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## Ridryder911 (Jan 29, 2008)

JPINFV said:


> No offense, but if you don't know what your medicantions do, you shouldn't be administering them. If you knew what they did (acetylsalicylic acid is an anti-coaglent whereas nitro is a vassal dialater), then you probably wouldn't be asking this question. Those drugs are not either/or.




Whoa!.... 

Sounds like you need to go back to your school and demand your money back! Sorry, but something is wrong ! Let's start back in cardiac care, when you should had been taught the general care of cardiac emergencies. As the poster describes.. if you don't know about the medications, then you probably should not be doing it...  *I am however; glad you are asking questions now*. 

Second I am sure JPINFV was being purposefully humorous it is vasodilator (don't know what a vassal dialater or coaglent is) (dilatation of the vessels i.e. veins, arteries, capillaries, venules) dilates. As well ASA  is * NOT* a blood thinner, it is a anti-platelet which prevent clots from forming (which is NOT the same as a "blood thinner" such as Heparin/Coumadin) ....but does have a blood thinning coagulant effect. Yes, there is a MAJOR difference. 

As well I have some REAL problems with anyone giving nitroglycerin (NTG) without having a 12 lead ECG interpreted prior to administration. The problem lies that patients are usually on or prescribed NTG for Angina not for having an AMI! Giving NTG blindly can be dangerous! Administering NTG to patients having a left ventricular infarct can actually cause more damage and YES.. potentially kill them! Thus the importance of a medical work up and referred to those that understand and treat cardiac care. 

Again, the only reason we allow Basics to administer most medications is because the safety factor that most laymen could do the same without a percentage of risks. ASA is not going to effect the major population, as well most patients that do have NTG in their premise, have a history of angina... hopefully, that is all it is.  

Medications are essential, just as essential they are to treat they all have potential dangerous side effects. 

R/r 911


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## MMiz (Jan 29, 2008)

Rid,

What is your reasoning for wanting an *interpreted* EKG prior to administration of nitro?  I've had old folks that pop nitro like they're tic tacs.  I absolutely understand that nitro is a medication that requires proper administration and monitoring, but I've never seen an MD actually request a patient to assess any vitals before popping the magic pills.


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## JPINFV (Jan 29, 2008)

Ridryder911 said:


> Whoa!....
> Second I am sure JPINFV was being purposefully humorous it is vasodilator (don't know what a vassal dialater or coaglent is)


Naw, I'm an idiot that needs to remember that Firefox spell checker + quick post box aren't friends... (i.e. it doesn't work for some reason in my browser). But (yea yea, conjunction violation), yea, it's not a peasant (vassal) dilator.


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## triemal04 (Jan 29, 2008)

MMiz said:


> Rid,
> 
> What is your reasoning for wanting an *interpreted* EKG prior to administration of nitro?  I've had old folks that pop nitro like they're tic tacs.  I absolutely understand that nitro is a medication that requires proper administration and monitoring, but I've never seen an MD actually request a patient to assess any vitals before popping the magic pills.


I've never heard of a doc asking a patient to check ANYTHING before taking a medication.  Why?  Because the average person wouldn't know how, would do it wrong, or would ignore the request.  Go figure.  

Luckily, we (some of us out there anyway) are just a leeeeetle better trained than the average person.  Anyway, the reasoning behind the 12lead is pretty simple:  give nitro the someone having the wrong kind of MI and you may very well kill them.  Couple links if you want to get into all the details:
http://www.aafp.org/afp/991015ap/1727.html
http://www.emedicine.com/MED/topic2039.htm

In a nutshell, inferior wall MI's often happen at the same time as right ventrical MI's.  When the right ventricle is affected, it stops pumping blood effectively, thus reducing the amout of blood available for the left ventricle to pump and thus maintain a BP.  So these people may or may not allready have a low BP; either way, it's compromised.  Now, if you throw nitro into the mix and decrease the preload to the heart, the amount of blood the right ventricle is moving is even less, and the BP really, really, REALLY takes a hit.  Bad things tend to follow.  Being able to read a 12lead will help you to decide wether or not you should be giving nitro to the patient.

Luckily right sided MI's are fairly rare, which is why people often get away with popping it or giving their patients nitro like it was candy.  But trust me, do it once and you will never, ever do it again.


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## Ridryder911 (Jan 29, 2008)

MMiz said:


> Rid,
> 
> What is your reasoning for wanting an *interpreted* EKG prior to administration of nitro?  I've had old folks that pop nitro like they're tic tacs.  I absolutely understand that nitro is a medication that requires proper administration and monitoring, but I've never seen an MD actually request a patient to assess any vitals before popping the magic pills.




The physician are fools then, and I would hate to be there malpractice carrier. They are gambling that they are having Angina, and not an AMI. Remember there is a BIG difference. The patients medial history, as well as I am sure serial ECG's, U/S, stress test, etc. then they will make the determination that it is an Angina event, not an AMI. So when the patient has "chest pain" they are hoping, that there pressure will be high enough that they can sustain the NTG administration. Thus the reason to wait " five minutes" apart to re-administer. As well, they are assuming since the chest pain has been determined to angina in nature. If the pain does not go away... there is a great potential it is not angina rather an AMI (or other etiology). 

In regards to an ECG prior let's review some basic cardiac physiology. Remember that the heart is filled by the venous system (inferior and superior vena cava-filled by the venule system) and dumps into the right chamber (right atrium)... right? Now, what happens if we were to dilate these vessels (in which NTG does) it would cause major vasodilation thus dilating or decreasing the peripheral resistance, and causing a decrease of the amount of blood and pressure entering the heart (preload factor). Now, what occurs if the heart does not sense there is enough blood or blood pressure? It increases the heart rate and stroke volume (contracts harder) thus increasing work demand .. thus if they are having an AMI causing the heart to work harder = increasing the AMI = infarct size larger... or basically in an inferior wall AMI or right sided AMI, possibly causing an major infarct size or death. 

NTG is NOT a direct contraindication but definitely a STRONG CONSIDERATION not to administer. Thus, the reason for not giving NTG for patient with low B/P is because they might have a left sided AMI. 
NTG is strong smooth muscle relaxer (hence the reason is also prescribed for esophageal spasms) and it dilates not just the coronary arteries but all smooth vessels.. hint: the reason people get a headache after NTG is administered- the cerebral arteries have just dilated and they got a head rush. 

Remember, there are *very few* site medications, that just work upon specific receptors or sites. Each medication has it side effects or desired effects dependent upon what the reason it is administered makes the difference. 

Even the most simplistic medications can be the most harmful.. ever seen a Tylenol or One-A-day overdose? .. thus the reason, medications administration as diagnosed by another provider is so dangerous. 


* noticed an error in previous post- it should be right sided AMI, not left. 
R/r 911


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## piranah (Jan 29, 2008)

well i know for RI the protocols are BP 90 or above for nitro and only with med contols approval, and only if its a prescription to that pt....but hey thats just RI lol


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## TKO (Jan 29, 2008)

I remember when one of the common contraindications was P<50.  Bradycardia is a common S/S of R-side MI.

I had a pt the other day that we were dispatched out to for VD (veak & dizzy).  Got there and he was ashen color with cynosis around the lips and B/P of 80/60 (more or less here).  He's pretty old and has a host of problems so we're kind of on high-alert with this gentleman.  

So we assess and treat with O2 and get into the Hx.  Anyway, find out that he developed chest pain earlier in the morning and his wife gave him his NTG. So that opens the door WIDE open and it's become quite obvious what has happened.  We ask the wife and sure enough it is confirmed.

There's no chest pain complaint so I give ASA and attempted a line (unsuccessfully) and away we go to the H.

Now, I won't reveal it here but anyone that isn't sure, is welcome to guess at what happened.  As most people with some experience will recognize the problem right away, I hope they won't say anything; let some of the less experienced ppl take a shot at it.  I'd say I see this problem 2 or 3 times a year, so I think it's good for inexperienced rescuers to start to recognize it now.


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## mikie (Jan 29, 2008)

thanks for all the answers, especially to Rid...very informational stuff, if i'm ever in need of EMS, i really hope you show up!

thanks again guys!


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## piranah (Jan 29, 2008)

...hmmm..seeing as though im a basic whos never worked on a truck yet.. im not surprised im stumped, but im still thinkin.....


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## Ridryder911 (Jan 29, 2008)

piranah said:


> but im still thinkin.....



That's the whole point for EMS forums!...

R/r 911


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## knxemt1983 (Jan 30, 2008)

Ridryder911 said:


> Whoa!....
> 
> Sounds like you need to go back to your school and demand your money back! Sorry, but something is wrong ! Let's start back in cardiac care, when you should had been taught the general care of cardiac emergencies. As the poster describes.. if you don't know about the medications, then you probably should not be doing it...  *I am however; glad you are asking questions now*.
> 
> ...



Rid, I am in Pm school right now, and remember them talking baout how nitro can be bad for a pt with a right anterior MI. Is this the same thing or is there some different pathophys behind the nitro be bad for a left infarct. They said that giving nitro to a pt with a right anterior would bottom the b/p out, and that could lead to dysrythmias etc. 

Here is what I think could cause problems. If there is a right side MI, then it would drop the B/P because it is reducing the amount of blood being sent to the pulmonary arteries already, because of the ischemic tissue, thereby less blood volume is making it to the left side of the heart and to the body reducing stroke volume and lowering the b/p. So giving nitro would dramatically increase this effect by reducing the preload which is one of the effects of nitro.
Now the left infarct I am thinking this would be bad because the nitro would decrease the afterload, because of lowered peripheral vascular resistance, to the point where it is going to seriously reduce the coronary circulation.


These are the ways I am trying to reason this out, I may be totally off base and if I am, please guide me in the right direction. Thanks for the info.


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## TKO (Jan 30, 2008)

What you witnessed, was one of those rare occurrences in EMTLife Hx -- Rid made an error.

Of course, he later corrected himself.  He never meant to say Left-sided AMI, he intended to say Right.

That's assuming I read your post correctly.  As per Hx, I make my share of mistakes all the time.


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## TKO (Jan 30, 2008)

piranah said:


> ...hmmm..seeing as though im a basic whos never worked on a truck yet.. im not surprised im stumped, but im still thinkin.....




If you think about chest-pain as a blockage (partial or complete), then what effect does that usually have on a pt's blood-pressure?  Is that consistent with what we see here?  Why?


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## SC Bird (Jan 30, 2008)

Lot of helpful info, Rid....thanks for the good read.

-Matt


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## skyemt (Jan 30, 2008)

mikie333 said:


> For us basics in the area, we can administer 7 drugs (O2 is included).  For chest pain, we have nitro spray and 'baby' asprin (4 tabs. for 324 mg)
> 
> My question is when to chose nitro or ASA and vise versa.
> 
> ...



Wow... as a basic, i can tell you you got away light out here... but... are you thinking about the big picture?  is it stable angina? relieved by rest? was it sudden onset at rest? has the pt taken their own Nitro? what were the effects?

if you just look at indications, and give meds without understanding how they work or seeing the bigger picture, you are not providing a good level of care... sorry to say it, but as a Basic, you can kill someone if you don't know what you are doing with these meds.

also, i find it hard to believe you would be able to administer Nitro without a line in place... what happens if the BP bottoms out? is it your Nitro you are administering, or are you saying you can help the patient administer his own? HUGE difference there... please clarify that for me...

thanks


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## knxemt1983 (Jan 30, 2008)

TKO said:


> What you witnessed, was one of those rare occurrences in EMTLife Hx -- Rid made an error.
> 
> Of course, he later corrected himself.  He never meant to say Left-sided AMI, he intended to say Right.
> 
> That's assuming I read your post correctly.  As per Hx, I make my share of mistakes all the time.



oh, ok. I think he actually edited that post while I was writing that question, it was up for about 5 hours cuz I was running calls while writing it. Thanks for pointing it out.

So is my thinking on the right sided MI along the right lines?


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## Ridryder911 (Jan 30, 2008)

You are correct on the right side AMI (sorry any confusion, I too was in between calls) as well your theory of poor pre-load causing problems. 

R/r 911


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## ResTech (Jan 30, 2008)

NTG is a very safe medication and in my opinion it is overboard to have a 12-lead before NTG. Only a small percentage... a very small percentage... of patients would be adversely effected and MI exacerbated with NTG. I've been doing this for 12 years as a career and active volunteer and NEVER once experienced a death or worsening of an MI from NTG. Could it happen... sure. Can a COPD patient stop breathing from to much O2 even though hypoxic? sure. 

What are the chances? What is the benefit vs risks? Should we withhold early nitro therapy from 99% of the population bcause of 1% that may have a worsening of their MI?


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## BossyCow (Jan 30, 2008)

We do not 'administer' NTG, we are however able to 'assist a pt with a prescribed medication'.  The difference is we don't make the call, being BLS, this is outside of our scope of practice. But, if someone has a prescription for nitro, which means they can take whether we want them to or not, we can help.  I have on few occasions, contacted MPD with a pt, 10:10 chest px, and a blood pressure that looks more like the dow than a vital sign.  I have been told by the MPD to administer NTG to the pt even though they did not have a scrip for it.  The difference is, it wasn't my call, it was the doc's.


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## mikie (Jan 30, 2008)

We can administer it, 1 spray, sublingually (0.4mg), up to three times with re-evaluations of vitals every 2-5 minutes post administration).


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## piranah (Jan 30, 2008)

ok so heres what i have....he could of had a embolism which would have  reduced cardiac output and so by giving him the nitro lowering his BP even more causeing a lack of input into the right atrium and then inevidebly causeing extreme hypoperfusion...putting him towards shock and giving him the cyanotic look and the 80/60....


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## Ridryder911 (Jan 30, 2008)

ResTech said:


> NTG is a very safe medication and in my opinion it is overboard to have a 12-lead before NTG. Only a small percentage... a very small percentage... of patients would be adversely effected and MI exacerbated with NTG. I've been doing this for 12 years as a career and active volunteer and NEVER once experienced a death or worsening of an MI from NTG. Could it happen... sure. Can a COPD patient stop breathing from to much O2 even though hypoxic? sure.
> 
> What are the chances? What is the benefit vs risks? Should we withhold early nitro therapy from 99% of the population bcause of 1% that may have a worsening of their MI?



Are you sure there were no risks if you did not do a 12 lead? Why one only look at a small view of an ECG. As those that really understand cardiology say ..."those that view in three, do *NOT* see".... And can you say there is a small percentage of inferior AMI's? Is this based upon your clinical experience or AMI's in the U.S.? What are you basing your data upon? As well, exactly how do you know you did not increase the size of the AMI? If you did not have a pre twelve lead, then you have nothing in comparison. Not all (especially in post-inferior wall AMI) are symptomatic as they increase in size. As well, NTG is usually not beneficial treatment in a true obstructive AMI in comparison to Angina. 

So you much rather gamble and take the chance of even causing more harm than to await to perform a 30 second twelve lead, that will help aid in diagnostic of the type of an AMI. Again, I am quite aware it may not affect ALL patients with an AMI, but just to cause increase work load in one patient is too many... all for an additional 30-45 seconds. I have seen many patients that "bottom out" when given just one dose of NTG. 

Do you not establish an IV prior to NTG administration as well? If not you are foolish. Then I ask you; what is the primary treatment of an inferior AMI ? 

Do you agree to give NTG prior to 12 lead in a BBB patient? (again only determined by a 12 lead) as well; knowing that those with a BBB (wider than 170ms) only have about a 25% ejection fraction. So what do you think happens to these patients when NTG is given? 

This is the same philosophy of not also believing in checking for bifascicular block/LBB before administering Morphine?  Realizing that even M.S. may or will further the slow conduction through the ventricles and having a high risks of inducing a complete heart block, possibly ventricular aystole. 

Attempting to compare oxygen toxicity to an inferior AMI has nothing even similar to comparison. The etiology and duration of time, percentage of occurrences has no similar comparison and is a very poor analogy. 

R/r 911


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## Ridryder911 (Jan 30, 2008)

I believe the purpose and emphasis of why EMT's are giving NTG to patients should be addressed. EMT's are treating the "chest pain" as primarily being anginal. If pain persists, or increases it probably is ischemic or an AMI.  ASA should have also been introduced by now, one of the very few medication known in EMS to really be beneficial in treating an AMI.

One of course has to follow local policies and restrictions no matter what. 

My point was to understand different philosophies of care and attempt to see "outside the box" and not just the cookie cutter treatment. There are different ways to skin a cat.... heck, it may not even have to be skinned..


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## mikie (Jan 30, 2008)

Rid...have you ever considered med school?!  or at this point becomming a professor? 

you truly are a great asset to this forum

and thanks to everyone!


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## TKO (Jan 30, 2008)

piranah said:


> ok so heres what i have....he could of had a embolism which would have  reduced cardiac output and so by giving him the nitro lowering his BP even more causeing a lack of input into the right atrium and then inevidebly causeing extreme hypoperfusion...putting him towards shock and giving him the cyanotic look and the 80/60....



LOL!  That's really over-thinking it.  A lot of times in EMS, you should employ one of the most important mnemonics of all: KISS (I am certain you know this one).

So you can guess that a "blockage" would cause hypertension.  Yet, we have hypotension.  So what happened between the initial chestpain and my later b/p reading to change hyper to hypo?  And why?  KISS!

It's good you are thinking.  Really good.  But some basic problem solving skills will serve you much better as an EMT than advance A&P will.  And most of those skills will come with experience.  We all had to start somewhere and see it once for ourselves.

I bet you get it on the next try!


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## piranah (Jan 30, 2008)

actually im in a medic class and we're going through our A/P and pathophysiology....so im kinda in that mindset right now...lol sorry bout the overkill.lol....ya i know what KISS means "keep it simple stupid"...


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## JPINFV (Jan 31, 2008)

TKO said:


> It's good you are thinking.  Really good.  But some basic problem solving skills will serve you much better as an EMT than advance A&P will.  And most of those skills will come with experience.  We all had to start somewhere and see it once for ourselves.



Of course the difference is that A/P can be taught whereas problem solving skills can't (but they can be developed, especially in certain courses).

I think a better saying than KISS is "If you hear hoof beats, think horses not zebras."


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## Ridryder911 (Jan 31, 2008)

KISS method is great for some cases but medicine is not always that simple. True many times the most easiest approach is using the most simplistic approach. I agree experience helps develop problem solving skills, but there is research demonstrating that we can help develop and address critical thinking skills (which are the same as problem solving skills). These are definitely needed for working in the field. EMS is not a black and white situation, rather gray and some cannot function or find it difficult. 

Before a mechanic can repair a car, they have to know the parts and how they work the same is true on the human body. Otherwise you will treating per shotgun or blanket approach.. a hit and miss type of treatment. 

I do like the Zebra analogy... my other point for those beginning is 
...._"First thing to do when treating a cardiac arrest is to check you own pulse_...


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## piranah (Jan 31, 2008)

I know exactly what your saying and i used to be a car tech so thats how i look at medicine i see the individual systems and parts in my mind and visualize what the problem is with the sign and symptoms that are given.


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## TKO (Jan 31, 2008)

Well, it is common sense that you should have lots of different mental tools at your disposal when employed in EMS.  An understanding of A&P, critical thinking skills and experience-based logic are all required for a successful career.

However, we should always approach a problem from the simplest point of view to begin with and then deal with the complicated as it presents.  Going in the reverse is just an easy way to get lost in the problem... I am sure we've all done that somewhere in the beginning or middle of our careers once or twice.


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## evantheEMT (Oct 27, 2014)

ASA isnt for pain! !!! Nitro is for pain.its important to give every patient asa unless theyre allergic to it or GI bleed.


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