# aortic aneurysms



## Veneficus (Jan 29, 2011)

This topic was broached in another thread and I was asked to do a write up about it, so here it is. 

First I must disclaim that I cannot possibly cover every detail in this thread. So I plan to condense it to what I think is important to this discussion, based on my knowledge, education and experience.

Here we go:

True Aortic Aneurysm: is defined as a permnant and irreversable widening of the blood vessel. In order to fit the criteria the dilation should be >50% of the diameter. (normal infrarenal values: 14-24mm in males, 12-21mm females) making any dialation 3cm or larger in a male or 2.6cm in a female an aneurysm.

The location of the abdominal aneurysm is often infrarenal, however it can be superior to or even involve the renal arteries. Also high as above the celiac artery. It often involves collateral circularing arteries such as the hypogastic, rarely inferior mesenteric, and 1 or 2 others, plus normal anatomical variations.

The thoracic aneurysm is often just at the level of the aortic valve (which has a directimpact on the valve function and well as coronary circulation. 

The reason for the abd localization is still under investigation. The prominant thoeries are that it is a collagen metabolism/structure deficency as well as tissue apoptosis from lack of blood supply from the absence of the vaso vasorum at this level, nonenzymatic glycosylization, atherosclerotic changes and hypertension.

Like all things where there are competing theories, the truth probably involves some combination.

The most important distinction of an aneurysm is that it involves all layers of the muscular artery.

So what does that mean to EMS?

There are several clinical findings that can point towards a potential Aortic aneurysm.

Risk factors include: HTN, smoking, family hx, currently under observation of aneurysm and male sex. (9:1 m/f ratio)

The most common findings in the thorax is: no symptoms followed by: chest pain radiating to the back, aortic regurgitation (heart tone), or cardiac failure from acute aortic syndrome. (look it up)

In the abd. is abd pain again radiating to the back. Palpable mass which increases in size on systole. Usually found in the area of the umbilicus, but anywhere from the costal margin to the bifurcation of the illiac ateries (which may be included) at the level of the umbilicus.

Usually minimally palpable aneurysm is 3cm. Which requires immediate evaluation and treatment. Especially if the pt has been taking nsaids. The sensitivity is ~50%. However the sensitivity increases as the size does being almost 80% sensitive at 5cm. (which is considered a vascular surgical emergency) Basically if the mass is bigger than all 4 of your fingers palpating it, life is bad.

This can be found on skillful palpation, ultrasonography, CXR, or CT. You do not need the radiology, but it really helps in fat people, where palpation is often difficult at best.

Which brings us to: The ruptured aortic aneurysm.

-Sudden onset of CP or abd pain. (often radiating to the back/retroperitoneal space)  
-Sudden collapse with transient hypotension/ALOC.
-History of aneurysm
-Rapid onset of pain/hypotension/sweating
-Unequal pulse or BP in upper extremities
-Absent/weak pulses or mottling/cyanosis in the lower exremities.

(for brevity, surgical treatment won't be described)

By the book, only 50% of rupture patients make it to the hospital alive. 
75%-95% die prior to completion of surgery. The ones who make it out of surgery can see post op complications increasing the mortality as high as 99%

Common complications include in order of occurance:
-Death (multiple etiologies including brain ischemia and swelling from the acute event, surgery, and resuscitation attempts)
-Renal failure
-Lower limb embolization
-Iscemic gut or infarction

The recommendations in our surgical textbook (and consequently our hospitals) include:
-Immediate transfer to the OR without resuscitation attempts in the ED.
-2 large bore IVs but *no fluid resuscitation therapy *prior to the entire surgical team being ready at the patient's side
-High flow oxygen via NRB prior to intubation
-Modest doses of analgesia (5-10mg morphine or equivalent) 
-*Fluid resuscitation to begin during surgery *starting with 8 units FFP and PRBCs (or whole blood which to my knowledge is only used by the military) and 8 units platelts.

(I intentionally left out discussion on pseudoaneurysm, cerebral aneurysm, and peripherial aneurysm or I would be typing for weeks.)

What this all means is: 

A ruptured aneurysm is extremely difficult to treat and survive. EMS can easily make these efforts futile by initiating crystalloid resuscitation or transporting the pt to a facility without onstaff surgical capability. 

Facilities, in my experience, without surgical staff who receive these patients immediately terminate efforts and resort to end of life procedures.

Some ALS treatments which support other organ function like RSI may be beneficial to these patients. However, this is one of the few time critical emergencies EMS will see, and as was pointed out in the other thread, a BLS response and mindset maybe more beneficial. 

The intracranial swelling on a patient with no blood in their veins is moot.     
Rasing a systolic or even measuring systolic BP is moot. The location of the hemorrhage and the leaking of the vessle wall will cause the patient to bleed out faster or cause total wall rupture. 

Additionally, SBP does not correlate to CVP which means you are measuring blood (via pressure) going out, but not blood coming back. Since organs (firstly the heart) are perfused by oxygenated blood completing the circuit, a break in the circuit makes your pressure measurements completely useless. Particularly if you are measuring water pressure instead of blood pressure because you infused a crystalloid. 

There was a study done, if I recall properly, by Dr. McSwaine that showed MAST can increase intraperitoneal pressure and pneumatically tamponade the aorta and control bleeding by reducing the space the bleed can go into specific to this pathology. 

Likewise, I have postulated in traumatic blood loss a long spineboard can act to increase pressure and reduce the space in the same manner as a surgical retropritoneal pack technique.

I know most EMS providers will now be thinking "our protocol says..." and I will agree it probably does. 

But it may have been written based on "internal hemorrhage" using thoery postulated in the 1960s, instead of specifically to "ruptured aortic aneurysm" with the knowledge of 2011.

While I always welcome the thoughts of the people here, I hope that serious consideration will be given to how you are treating the patient when you suspect this pathology. 

Rather than simply following a protocol, there is always the option to contact medical control and have a chat about it. While tht may seem counter intuitive. Arguing against a treatment that is far more likely to harm the very small chance the patient has survive is not only patient advocacy, but better medicine that performing that treatment inspite of such knowledge.


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## medicRob (Jan 29, 2011)

Thanks for the post, Veney-Feeky. 

Here is a good question.. How many of you out there have protocols that call for running as much fluid as it takes to get that magic number of 90 mmHg? 

If so, having read this post, do you feel like next time you come across a situation such as this (I realize you can't just look at a patient and say 'Oh, that's a triple A") would you still follow the protocol or would you be more likely to call in to medical control to discuss alternative approaches? Do you feel confident enough to present your case to medical control?


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## socalmedic (Jan 29, 2011)

we have 1000ml NS prior to contact. my question is, would pressors be beneficial to this patient? we only dopamine and epi but would they even be beneficial, close a torn wall or would the increased PVR be more likely to make the tear worse?


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## Akulahawk (Jan 29, 2011)

socalmedic said:


> we have 1000ml NS prior to contact. my question is, would pressors be beneficial to this patient? we only dopamine and epi but would they even be beneficial, close a torn wall or would the increased PVR be more likely to make the tear worse?


Your patient has a hole in the Aorta. Use of pressors might temporarily give you better "numbers" but won't stop the problem. Take a hose, punch a hole in it and put a nozzle on the end while observing what happens to flow of water through that hole you punched in the hose. That's what pressors will do. Similarly, start with a low flow through the hose and slowly open the valve. Watch what happens with the flow through that hole you punched... that's what more fluid does.

Good prehospital TX? Once you've identified that you've got a patient with a rupturing aortic aneurysm, scoop and run. Do everything else en-route. Large bore IV (lock or TKO) and apply MUCH diesel. If you have the PASG/MAST on your truck, this is about the only time that it's use might actually be beneficial.


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## Veneficus (Jan 30, 2011)

socalmedic said:


> we have 1000ml NS prior to contact. my question is, would pressors be beneficial to this patient? we only dopamine and epi but would they even be beneficial, close a torn wall or would the increased PVR be more likely to make the tear worse?



Dopamine works primarily on smooth muscle of arterioles which would increase peripheral vascular resistance (PVR), not on the walls of muscular arteries.

Epi will also increase the heart rate and PVR.(bleed faster)

Also, consider the pathophys that the muscular tissue walls (and therefore muscle cells) are destroyed which caused the dilation initially.


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## TheGodfather (Oct 20, 2011)

First of all, apologies for bringing this back from the dead. -----now onto the question:

Earlier today while at a work training, a coworker (emtp) and I were chit-chatting about EMS and previous calls etc etc etc....anyway, she brought up one of her previous calls she had a month or so back and we got to debating. 

In order for you all to understand, ill give the 4-1-1 on what her version of the call was (to the best of my knowledge), as well as my questions regarding her choices on said call:

She said she responded to a male patient at a wedding (unknown if ETOH) CC of acute abdominal pain. When she assessed this patient, she said she saw a VISIBLE abdominal mass that "almost made her puke because it looked so gross". She stated this mass was midline (did not state where at in relation to umbillicus) and tender to the touch. she said when she ASKED this individual (closed ended question mind you) he stated that yes, he did have abdominal and back pain. She also stated there was "nausea" (again, unknown if ETOH) and no vomiting. When she palpated this visible abdominal mass, she stated it was pulsating, and also when she asked the patient if it got bigger, he agreed. 
VITALSatient is hemodynamically stable, vitals all normal -- pt JUST complaining of pain (only abnormality to VS is slight sinus tach)
TREATMENTS: IV kvo, o2, cardiac monitoring

---pause--- ok, now treatment thus far; not terrible, not even bad. but here is where i start questioning it...

once the patient was loaded, she got on the horn with the receiving hospital -- what she told them was this patient HAS a AAA, it is palpating, and is increasing in size. needless to say, they stat surgery to the ER, prep the resus team, the whole 9.... 

End result: hernia.
Secondary end result: PISSED er staff

Entire list of S/S
-abd pain
-visible abd mass (midline)
-back pain (after closed ended yes/no question)
-"pulsating" felt on mass
-sinus tach


Now, here are some of my questions - (go easy on me please)

1. i do not disagree that some of the symptoms shown correlate with the tell-tale AAA criteria --- BUT; how can you justify telling the ER staff this wild claim with broad symptoms that can be related to NUMEROUS other abdominal problems (less the visible mass) --- we are paramedics, we dont tell the receiving physician at the other end of the radio our "diagnosis" because we DO NOT diagnose.. shouldn't she have just reported her clinical findings rather than tunnel into just telling the doctor her "professional opinion"?

2.) she suspected a AAA, the hospital is less than 5 miles away, yet she still goes lights and sirens...... for this condition, i'd feel like the added stress of hearing all the commotion would be detrimental to the "AAA" patient's condition, correct?

3.)from my understanding, AAA could be ruled out right off the bat (more or less), because (from my understanding) these are not visible to the naked eye....am i completely off here?

maybe im way off base here, but this sparked a huge debate today so i'd like some clarification.

please be nice!


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## ArcticKat (Oct 20, 2011)

TheGodfather said:


> When she assessed this patient, she said she saw a VISIBLE abdominal mass that "almost made her puke because it looked so gross".



As soon as I read this my mind went to Umbilical Hernia.


Now, here are some of my questions - (go easy on me please)



TheGodfather said:


> 1.how can you justify telling the ER staff this wild claim with broad symptoms...we dont tell the receiving physician at the other end of the radio our "diagnosis" because we DO NOT diagnose..



Sure we diagnose.  We do it all the time.  Ever give D50? You just diagnosed hypoglycemia.  It's reasonable to voice your suspicions during your report but in such a manner that the triage nurse knows it is your suspicion.



TheGodfather said:


> 2.) she suspected a AAA, the hospital is less than 5 miles away, yet she still goes lights and sirens......



A little from column "A", a little from column "B".  A "AAA" can become unstable in quick order.  Personally I wouldn't have, but then, I suspected a hernia.  Your S/S is lacking though.  Full set of vitals?



TheGodfather said:


> 3.)from my understanding, AAA could be ruled out right off the bat (more or less), because (from my understanding) these are not visible to the naked eye....am i completely off here?



Not completely, but a little.  The mass can be visible if the patient is supine, but it looks nothing like a hernia.  More like something rippling under the skin, like on Alien.  A large AAA will make the entire abdomen pulsate.  Try it on yourself.  Lay on your back and look at your belly, you'll likely see it pulsate slightly.



TheGodfather said:


> please be nice!



How was that for ya?

Sure, she screwed up, but we all do at times and the patient suffered no harm from it.  Only her pride.


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## TheGodfather (Oct 20, 2011)

ArcticKat said:


> Sure we diagnose.  We do it all the time.  Ever give D50? You just diagnosed hypoglycemia.  It's reasonable to voice your suspicions during your report but in such a manner that the triage nurse knows it is your suspicion.


I complete agree with you there. For conditions, such as hypoglycemia, no doubt we can diagnose because we have all the tools capable of making the diagnosis. What I was (in a way) getting at is it isn't likely that we can make a set-in-stone diagnosis for those conditions (ie diverticulitis, PE, etc) requiring additional tests (ie CT, xray, lab testing)... in my opinion, its more or less our job to consider any differential diagnosis', rule out whatever possible, and present the findings as well as (if necessary) our "field prediction" (without getting in the realm of tunnel vision) for the docs to consider/build off of. (if that makes any amount of sense) lol 



ArcticKat said:


> A little from column "A", a little from column "B".  A "AAA" can become unstable in quick order.  Personally I wouldn't have, but then, I suspected a hernia.  Your S/S is lacking though.  Full set of vitals?


Makes sense. Like I said, I'm still in the dark about the whole call. She was really vague with her treatments and with the vitals signs. I heard about it from her emt partner and the two stories I got contradict each other, so more than likely parts of the story could be twisted/sugar coated. The whole debate lasted about 3-4 minutes, but for some reason it stuck with me for the rest of the day.



ArcticKat said:


> How was that for ya?
> 
> Sure, she screwed up, but we all do at times and the patient suffered no harm from it.  Only her pride.


Very good! Complex question, simple answer! I appreciate the input!


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## mycrofft (Oct 20, 2011)

*Parse and sweep, parse and sweep.*

1. When you think dissecting AAA, think a massive centerline abd gunshot or stabbing except no exterior wound.
2. A *visible, growing*, pulsatile mass is either going to burst out and skitter across the floor of your spaceship, or it is an abdominal hernia or a diaphysis of the rectus abdominus, probably. Nausea and increased protrusion with attempts to tense by sitting up are pretty confirmatory. So are bowel sounds. 
3. Predisposing factor for both abdominal hernia and dissection abdominal aneurysm is Marfan's Syndrome, or Marfanoid traits.


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## TheGodfather (Oct 21, 2011)

haha good point!


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## mycrofft (Oct 26, 2011)

*Heard one yesterday*

Fire chief responded with EMS to a house, man with chest/abdominal pain. Chief saw pulsing swollen area of man's belly as he tried to sit up. Chief called all the guys in to "see this, this guy hasn't got a chance, you will not see this very often" thinking this was an aneurysm.Pt home within a week , it was a midline abdominal hernia.

What a way to go, encircled by sweaty guys in smelly fire gear, pointing-at and touching your belly as you try to sit up and talk to them.

wacko:   wah-wah-wah-Wa-a-a-h!).


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