# Unstable SVT Treatment



## DippyDo (Sep 24, 2014)

So I recently had a discussion with an instructor regarding the treatment of an unstable SVT (hypotensive, decreased LOA's, etc). The obvious answer was synchronized cardioversion, but the instructor stated that a fluid bolus would also be pertinent for this patient. I personally didn't think this was a good option as the problem with SVT is related to the heart rate not the fluid levels in the body. Since the heart is pumping to fast to allow adequate filling I felt additional fluid would just sit in the vascular space and create issues. The current ACLS guidelines don't state anything about fluid treatment for unstable SVT, so I was wondering if anyone had insight on the topic. Any sources you could provide would be appreciated as well.


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## STXmedic (Sep 24, 2014)

If the rate isn't too ungodly fast, a fluid bolus could help you distinguish from a compensating sinus tach (ie sepsis or severe dehydration) vs a true arrhythmia requiring pharmacological/electrical intervention. Now if the rate is north of 200 or obviously well outside of the patient's max HR range, then I'd go straight to SVT mitigation.


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## cprted (Sep 24, 2014)

It comes down to why are they tachy?  If they're tachy and hypotensive because they're hypovolemic, do you think cardioverting them is going to fix the problem?  No, because the problem isn't due to an electrical conduction issue.  

ACLS doesn't address this because ACLS is a course about heart problem ... sepsis secondary to a raging pneumonia isn't a heart problem, though that pt could present with a high rate and low pressure.  Get a good history.


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## DippyDo (Sep 24, 2014)

cprted said:


> It comes down to why are they tachy?  If they're tachy and hypotensive because they're hypovolemic, do you think cardioverting them is going to fix the problem?  No, because the problem isn't due to an electrical conduction issue.
> 
> ACLS doesn't address this because ACLS is a course about heart problem ... sepsis secondary to a raging pneumonia isn't a heart problem, though that pt could present with a high rate and low pressure.  Get a good history.



I'm asking this as a hypothetical situation where you indeed know the cause of their SVT is a cardiac conduction disturbance. Would a fluid bolus to a hypotensive patient with this etiology be beneficial or detrimental.


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## teedubbyaw (Sep 24, 2014)

What they said.



> Would a fluid bolus to a hypotensive patient with this etiology be beneficial or detrimental.



Nope. Considering the vast majority of true SVT is from a reentry circuit. Fluid is something to always keep in mind with pedi's, though.


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## cprted (Sep 24, 2014)

DippyDo said:


> I'm asking this as a hypothetical situation where you indeed know the cause of their SVT is a cardiac conduction disturbance. Would a fluid bolus to a hypotensive patient with this etiology be beneficial or detrimental.


What your instructor was getting at was that not everyone who is in a narrow fast rhythm is in a renetry SVT, there are other etiologies to consider.

If you've gathered a good history and you've determined you're dealing with an AVNRT, etc, then no, a fluid bolus isn't going to be beneficial because fluid volume isn't their problem.


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## DippyDo (Sep 24, 2014)

cprted said:


> What your instructor was getting at was that not everyone who is in a narrow fast rhythm is in a renetry SVT, there are other etiologies to consider.
> 
> If you've gathered a good history and you've determined you're dealing with an AVNRT, etc, then no, a fluid bolus isn't going to be beneficial because fluid volume isn't their problem.



This discussion occurred during a clinical rotation, after the patient was given adenosine and had his rhythm converted from SVT to NSR. AVNRT was the etiology for sure, though I should have specified AVNRT in my main post.

Thanks for the answer


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## STXmedic (Sep 24, 2014)

cprted said:


> What your instructor was getting at was that not everyone who is in a narrow fast rhythm is in a renetry SVT, there are other etiologies to consider.
> 
> If you've gathered a good history and you've determined you're dealing with an AVNRT, etc, then no, a fluid bolus isn't going to be beneficial because fluid volume isn't their problem.


The instructor may have also been blindly quoting others without knowing the rationale. Not all instructors/preceptors know what they're talking about...


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## tpchristifulli (Sep 25, 2014)

All the gas in world doesn't fix a car if the engines broke.


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## Carlos Danger (Sep 25, 2014)

DippyDo said:


> So I recently had a discussion with an instructor regarding the treatment of an unstable SVT (hypotensive, decreased LOA's, etc). The obvious answer was synchronized cardioversion, but *the instructor stated that a fluid bolus would also be pertinent for this patient*. I personally didn't think this was a good option as the problem with SVT is related to the heart rate not the fluid levels in the body. *Since the heart is pumping to fast to allow adequate filling I felt additional fluid would just sit in the vascular space and create issues.* The current ACLS guidelines don't state anything about fluid treatment for unstable SVT, so I was wondering if anyone had insight on the topic. Any sources you could provide would be appreciated as well.



Perhaps he meant "this specific patient" was in need of IVF for reasons unrelated to the SVT?

I suppose in theory, increasing preload with some IVF _might_ help some if you had no way to treat the SVT, but it sounds like he may have been referring to something unrelated.


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## Christopher (Sep 25, 2014)

DippyDo said:


> So I recently had a discussion with an instructor regarding the treatment of an unstable SVT (hypotensive, decreased LOA's, etc). The obvious answer was synchronized cardioversion, but the instructor stated that a fluid bolus would also be pertinent for this patient. I personally didn't think this was a good option as the problem with SVT is related to the heart rate not the fluid levels in the body. Since the heart is pumping to fast to allow adequate filling I felt additional fluid would just sit in the vascular space and create issues. The current ACLS guidelines don't state anything about fluid treatment for unstable SVT, so I was wondering if anyone had insight on the topic. Any sources you could provide would be appreciated as well.


Truly unstable SVT's are relatively rare and pretty much only happen at extreme rates (>200). You're more likely to encounter an unstable SVT due to atrial fibrillation than say a reentrant rhythm like AVNRT or AVRT.Consider that with a narrow complex tachycardia you are still utilizing the normal conduction system (and in about 10% of cases an accessory pathway too). It will be a very rare day you cardiovert a narrow complex tachycardia in the field.

Per ACLS, there is not really anything wrong with running fluids while setting up to cardiovert. They really only say to do "immediate" cardioversion if the patient is "extremely unstable." In an NCT...I'm going to want them to be flat out obtunded (straight up drooling) before I ditch an IV, fluids, and sedation prior to cardioversion.


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## Nova1300 (Sep 25, 2014)

If this patient was hypotensive, I would give some fluid while preparing to convert the rhythm.  

As a general principle, I find that heart rates from sepsis rarely get out of the 120's.  A-fib usually stays under 150.  Accessory pathways try to fly out of the chest. 

A little fluid and some T-berg before cardioversion frequently gives you a bit more hemodynamic room for sedation.


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## Handsome Robb (Sep 25, 2014)

Is anyone allowed to do concurrent pain and sedation for cardioversion or pacing? I've always wondered why we use anxiolytics rather than analgesics since it's a painful procedure. Also, expanding on Nova's thought about getting a little more wiggle room for sedation, wouldn't it be just as if not more effective to use a smaller dose of midazolam concurrently with fentanyl rather than just straight midazolam? Not only is fentanyl very hemodynamically "stable", the smaller dose of midaz is going to to have less vasoactive actions than a big slug of it. The combo can render the same if not better results.

We can do concurrent pain and sedation for pain associated with a large muscle mass such as a femur fracture or back spasms on standing orders, only can use sedation for cardioversion and pacing without OLMD.

As far as the question about fluids, it's been answered well already. Not necessarily going to be a bad thing but if someone is symptomatic enough to warrant cardioversion as the first line treatment why go doinking around getting a line and spiking a bag? It always makes me wonder when people say "while I setup for cardioversion". It takes all of 30 seconds to place pads, select your energy setting and sync the monitor.


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## DesertMedic66 (Sep 25, 2014)

Handsome Robb said:


> Is anyone allowed to do concurrent pain and sedation for cardioversion or pacing? I've always wondered why we use anxiolytics rather than analgesics since it's a painful procedure. Also, expanding on Nova's thought about getting a little more wiggle room for sedation, wouldn't it be just as if not more effective to use a smaller dose of midazolam concurrently with fentanyl rather than just straight midazolam? Not only is fentanyl very hemodynamically "stable", the smaller dose of midaz is going to to have less vasoactive actions than a big slug of it. The combo can render the same if not better results.
> 
> We can do concurrent pain and sedation for pain associated with a large muscle mass such as a femur fracture or back spasms on standing orders, only can use sedation for cardioversion and pacing without OLMD.
> 
> As far as the question about fluids, it's been answered well already. Not necessarily going to be a bad thing but if someone is symptomatic enough to warrant cardioversion as the first line treatment why go doinking around getting a line and spiking a bag? It always makes me wonder when people say "while I setup for cardioversion". It takes all of 30 seconds to place pads, select your energy setting and sync the monitor.


We can use pain meds for TCP.


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## Handsome Robb (Sep 25, 2014)

DesertEMT66 said:


> We can use pain meds for TCP.


Can you use them concurrently with benzodiazepines?

I think benzos have a roll in these procedures. One, because I'd be anxious as hell having someone put pads on me and zap me and two, the anterograde amnestic effects are going to be beneficial for the patient. Couple that with opiod analgesia and you can make a very uncomfortable and scary situation a lot more comfortable for the patient, if they even remember it at all.


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## DesertMedic66 (Sep 25, 2014)

Handsome Robb said:


> Can you use them concurrently with benzodiazepines?
> 
> I think benzos have a roll in these procedures. One, because I'd be anxious as hell having someone put pads on me and zap me and two, the anterograde amnestic effects are going to be beneficial for the patient. Couple that with opiod analgesia and you can make a very uncomfortable and scary situation a lot more comfortable for the patient, if they even remember it at all.


They are both listed as standing orders for us in TCP. Nothing I have seen says we can't


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## Nova1300 (Sep 26, 2014)

I understand why you would want to use both.  It makes sense that the procedure is painful and nobody wants to remember getting that punch to the chest. 

But, just a couple quick points - more for pondering than to change your practice. 

Remember that cardioversion is a very quick (albeit painful) procedure.  Unlike TCP where there will be continued stimulus, usually cardioversion is a one-shot deal and you are done.  There are some that may require a couple doses of electricity, but most will convert with that first zap.  And yes, then the newly stable patient can relax and enjoy the remainder of their opiate and benzo and it is usually not a problem in the young healthy patient. 

Fentanyl as monotherapy is generally very hemodynamically stable.  But, there is a synergism between fentanyl and benzos which is much more highly pronounced in elderly and unstable patients.  Both the respiratory and the hemodynamic effects are magnified when used in combination - and those effects be dramatic in this population.  For example, the little old lady with systolic failure (EF 20%) and a-fib RVR with marginal blood pressure.  She is much more likely to tank with the combination than the 27 yo with AVNRT.  However, in my experience, those same patients do OK if you stick with monotherapy. 

In my own practice, cardioversion never gets opiate.  But, I think you can argue it both ways, especially in younger patients.


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## Christopher (Sep 30, 2014)

Nova1300 said:


> As a general principle, I find that heart rates from sepsis rarely get out of the 120's.  A-fib usually stays under 150.  Accessory pathways try to fly out of the chest.



In our AF patients who have adequate rate control due that seems to be my finding as well. Others seem to rock out in the 150's to 170's. Those are quite a bit more insidious...and with consultation I may try some rate control into the 110-120's. Not a fun patient to have.

As far as AP's, only atrial fibrillation with an AP reliably causes excessive rates (>220; although younger patients will typically exhibit extremes of rates). Most AVRT's hover in the 170's as they're still rate limited by the patient's AVN (typical CL of 350ms; Curr Probl Cardiol 2008; 33:467-546).


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## Carlos Danger (Sep 30, 2014)

Handsome Robb said:


> Is anyone allowed to do concurrent pain and sedation for cardioversion or pacing? I've always wondered why we use anxiolytics rather than analgesics since it's a painful procedure. Also, expanding on Nova's thought about getting a little more wiggle room for sedation, wouldn't it be just as if not more effective to use a smaller dose of midazolam concurrently with fentanyl rather than just straight midazolam? Not only is fentanyl very hemodynamically "stable", the smaller dose of midaz is going to to have less vasoactive actions than a big slug of it. The combo can render the same if not better results.



In an otherwise healthy patient with a good BP, I like to use "2 & 2" (2 cc's each of fentanyl and versed) as premedication for most procedures. In the old, fragile patient that Nova describes, I don't use opioid either; they typically get fentanyl OR versed, and as was pointed out, there really is no need for opioid for cardioversion since the painful stimulus is so brief. There are those who would disagree of course, but I don't think you'l find too many people who have been cardioverted on only versed who will complain about how much pain they were in after the procedure.

Propofol works well too of course, but that isn't an option for most EMS providers. I've seen etomidate used in sicker patients, but I've personally never used it for procedural sedation. I'd avoid ketamine in these patients, though I'm sure it is used by some.

If they were truly "unstable" hemodynamically, I would probably forgo premedication altogether. Depends on the specifics of the situation, of course.


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## 46Young (Sep 30, 2014)

Nova1300 said:


> If this patient was hypotensive, I would give some fluid while preparing to convert the rhythm.
> 
> As a general principle, I find that heart rates from sepsis rarely get out of the 120's.  A-fib usually stays under 150.  Accessory pathways try to fly out of the chest.
> 
> A little fluid and some T-berg before cardioversion frequently gives you a bit more hemodynamic room for sedation.



That's my experience with sepsis and A-Fib as well.

Regarding Trendelenberg, just elevating the legs a little isn't going to do much, and it's only transient. I don't remember if it was Dr. Lo or Tom Bouthillet, but I picked this up from one of them at the last EMS Symposium in Norfolk - if you lay the patient flat, and elevate the patient's legs 90 degrees, it's the same as a 500cc NS bolus, but it's only transient. This is useful to see if you do see a brief improvement in the patient's condition, or if the pt has an untoward reaction. This is a good way to cheat and see if a fluid bolus would help your patient, with much less risk than giving the fluid. 

This crossed my mind once when considering CPAP for the borderline hypotensive with APE, to elevate the legs and get a quick BP bump to offset the tamponade effect on the coronary vasculature and venous return regarding BP, but lying the patient flat was not advisable. I just started the CPAP with a bag hanging KVO, and Dopa mixed and at the ready. If the pt decompensated, I would be bagging anyway, so I decided that CPAP was reasonable even with a SBP of 90. The pt did well.


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## 46Young (Sep 30, 2014)

Handsome Robb said:


> Is anyone allowed to do concurrent pain and sedation for cardioversion or pacing? I've always wondered why we use anxiolytics rather than analgesics since it's a painful procedure. Also, expanding on Nova's thought about getting a little more wiggle room for sedation, wouldn't it be just as if not more effective to use a smaller dose of midazolam concurrently with fentanyl rather than just straight midazolam? Not only is fentanyl very hemodynamically "stable", the smaller dose of midaz is going to to have less vasoactive actions than a big slug of it. The combo can render the same if not better results.
> 
> We can do concurrent pain and sedation for pain associated with a large muscle mass such as a femur fracture or back spasms on standing orders, only can use sedation for cardioversion and pacing without OLMD.
> 
> As far as the question about fluids, it's been answered well already. Not necessarily going to be a bad thing but if someone is symptomatic enough to warrant cardioversion as the first line treatment why go doinking around getting a line and spiking a bag? It always makes me wonder when people say "while I setup for cardioversion". It takes all of 30 seconds to place pads, select your energy setting and sync the monitor.



Do you know what departments are using a benzo/fent combination for sedation, or for pain management with a Fx? I'd like to present this to EMS admin and the OMD if other departments can


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## Angel (Sep 30, 2014)

46Young said:


> Do you know what departments are using a benzo/fent combination for sedation, or for pain management with a Fx? I'd like to present this to EMS admin and the OMD if other departments can


 
SSV (sierra sacramento valley) http://www.ssvems.com/?page_id=280
T6, isolate injury


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## Tigger (Sep 30, 2014)

46Young said:


> Do you know what departments are using a benzo/fent combination for sedation, or for pain management with a Fx? I'd like to present this to EMS admin and the OMD if other departments can



Teller County Colorado. Protocols attached, though they are a bit dated now with the new medical direction having eliminated a max dose from the pain control protocol, _if benzos are not used._

Incidentally our new medical director has requested we cut down on this combination's use as it apparently could be considered starting down the conscious sedation road, which is out of scope. We now have Ketamine, which can be used with a benzo or opoid.

Actually I can't figure how to attach PDFs anymore (oops). Here is the quote, I can message you the pdf if needed.

2013 Teller County Pre-Hospital Protocols  Page 235
 Patients aged 12-55 years, who are suffering from joint dislocations
and/or angulated fractures, and in significant pain from such, may
(as an option) be given 0.5 mcg/kg of fentanyl with 5.0 mg of
diazepam IV. Use two separate syringes, one for each medication. 

 Patients older than 55 years of age, who are suffering from joint
dislocations and/or angulated fractures, and in significant pain from
such, may (as an option) be given 0.5 mcg/kg of fentanyl  with 2.5
mg of diazepam IV. Use separate syringes for each medication. 

 Patients  6-12 years of age, who are suffering from joint dislocations
and/or angulated fractures, and in significant pain from such, may
(as an option) be given 0.5 mcg/kg of fentanyl concomitantly with
0.2 mg/kg of diazepam (to a maximum of 5.0 mg) IV. Use separate
syringes. 

 Be advised that the presence of debilitation, respiratory disease,
fluid and/or electrolyte abnormalities, and CNS depressants may all
have profound effects on patients receiving these medications.
Either do not use the above medications or provide  them in
small increments and be very alert to hemodynamic and respiratory
parameters


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## Brandon O (Oct 2, 2014)

46Young said:


> This crossed my mind once when considering CPAP for the borderline hypotensive with APE, to elevate the legs and get a quick BP bump to offset the tamponade effect on the coronary vasculature and venous return regarding BP



Dunno about this one. The increased afterload might make things worse. Anyway, what would you do after the effect wore off?


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## MonkeyArrow (Oct 2, 2014)

Brandon O said:


> Dunno about this one. The increased afterload might make things worse. Anyway, what would you do after the effect wore off?



I would hope that you would be at or near the hospital. Nearly all of the truly needed ALS interventions we do pre-hospitally are temporizing measures, they buy enough time to get the patient to definitive care. Unless he practices in a rural environment with extended transport times, the next steps probably will be the hospital's to figure out.


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## KellyBracket (Oct 3, 2014)

46Young said:


> Do you know what departments are using a benzo/fent combination for sedation, or for pain management with a Fx? I'd like to present this to EMS admin and the OMD if other departments can



That isn't analgesia, it's procedural sedation. Which is cool, if that's what you're shooting for.

The recent evidence, however, suggests that benzos have no role in augmenting analgesia, or in "sparing" higher doses of opiods - for a quick review see "*For better pain control, add a benzo? (Part 1 - Trauma)*"


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## Handsome Robb (Oct 3, 2014)

@46Young REMSA does it.


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## Anjel (Oct 6, 2014)

Oakland county, MI


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