# Stroke questions



## terrible one (Jun 15, 2009)

How do you guys treat a stroke patient?

80% of strokes are ischemic in nature. Yet, a lot of protocols say high flow o2, however, the brain is reading the c02 levels. Thereby increasing o2 concentration decreases the c02 (that is being registered) and the ischemia worsens by reducing the blood flow to the brain....

So Oxygen or not? Depends on pt? SpO2 levels?

Also, they say to check sugar levels. On a pt with low sugar and stroke like symptoms do you give it? If its a hemorragic storke are you making the bleed worse by giving sugar and increasing the swelling thats developing?

Sorry if these are dumb questions just looking for some clarification (new medic)
thanks


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## daedalus (Jun 16, 2009)

Well, I know that in line with the recent research into re-perfusion injuries, I am told that 2-4 LPM via Nasal Cannula is most appropriate unless the patient is systemically hypoxic. VentMedic could probably tell you more.


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## marineman (Jun 16, 2009)

daedalus said:


> Well, I know that in line with the recent research into re-perfusion injuries, I am told that 2-4 LPM via Nasal Cannula is most appropriate unless the patient is systemically hypoxic. VentMedic could probably tell you more.



Protocol here calls for NC @ 2-4 but I too will hold further comment for the master.


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## SoCal (Jun 16, 2009)

In the case of a hemorrhagic stroke, if you hyperventilate and the brain gets adequate oxygen, the result will be vaso-constriction, barring stable variables.

Just a thought.... curious to hear other's answers...


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## akflightmedic (Jun 16, 2009)

In regards to you low BGL versus stroke presentation, I have had that exact scenario. 

Here is what I did: I called med control and asked the doc what he wanted me to do. Protocol wise, yes I could have given it but I wanted my bases covered.
He ordered me to give half an amp, which I did.
Patient's BGL improved however CVA symptoms were still present, thereby ruling out the differential dx of low BGL being the cause of the weakness/paralysis.
The patient was indeed having a stroke, confirmed later on.


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## VentMedic (Jun 16, 2009)

Let's start with some basics. 

I also take "cO2" to be in reference to Carbon Dioxide (CO2) and not content of Oxygen.

Also, here is the link for some to review OXYGEN.
http://www.ccmtutorials.com/rs/oxygen/index.htm

Hyperoxygenation is NOT Hyperventilation.

Hyperoxygenation is an increase in PaO2.

Hyperventilation is a decrease in PaCO2.

Giving oxygen does not decrease the PaCO2. In some cases it may increase the PaCO2 due mainly to an increase in the ratio of dead space to tidal volume (Vd/Vt) which is probably from reversal of hypoxic pulmonary vasoconstriction. This is another discussion for those who follow the recipe "NEVER give more than 2 L NC to a patient with COPD".

When learning to intubate, some Paramedic students use the term "hyperventilate" when actually it should be "hyperoxygenate". The goal is to increase PaO2. You want to maintain or achieve a normal CO2 (normocapnia) and not hypocapnia. If you still think you hyperventilate the patient, please review the AHA position on this issue as to why the ventilatory rate has been changed in the ACLS guidelines.

High levels of CO2 will cause cerebral vasodilation. However, we no longer hyperventilate (decrease PaCO2) a head injury due to the chances of vasoconstriction or inducing spasm. We maintain the CO2 levels at the lower range of normal. 

Now for the delivery terminology.

When taking about physiological effects of oxygen, refer to the FiO2. "High Flow" tells one little in the medical world since a 24% Venturi mask is a high flow device. A NRBM is not. 

For ischemic CVAs, there are several issues to consider rather than a blanket recipe of "2 - 4 L NC". 

What is the blood pressure? Diastolic and/or Systolic too high or too low? Adequate perfusion?

Airway? Snoring? Aspiration? Pre-existing pulmonary and/or cardiac conditions?

We will often maintain close to normal oxygenation and will usually try to achieve that through SpO2 unless we know other conditions that may influence delivery such as anemia or sickle cell. We rarely do an Arterial Blood Gas (ABG) due to the possibilty thrombolytic treatment but can find many of the values needed from venous lab work. What isn't in print can usually be calculated.

It is also not uncommon to see different positions on reperfusion theories and tissue ischemia concerning hyperoxygenation by a high FiO2 system or possibly HBO. The patient's "oxygen clock" will be closely monitored during this time. 

There's still a lot of research to be done. In the ICU, we have the capability to monitor cerebral perfusion, O2 consumption, ABGs and SjvO2. I can tell you that no two patients are always given the same amount of oxygen (FiO2) to stay within the guidelines of the parameters chosen for THAT patient by the etiology and extent of their injury or other systemic injuries and complications.


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## daedalus (Jun 16, 2009)

VentMedic said:


> Let's start with some basics.
> 
> I also take "cO2" to be in reference to Carbon Dioxide (CO2) and not content of Oxygen.
> 
> ...


I can assume than that in the field (because we do not have the ability to check ABGs, cerebral perfusion, etc) that if the patient is not in respiratory distress, has a good sp02 reading and no history that would compromise that reading (anemia, etc) that forgoing the blanket 15 L for everyone and using a nasal cannula is more appropriate?


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## Ped101 (Jun 16, 2009)

Personally, i always go with the 15 lpm Oxygen, because if it's hemmorragic the vasocinstriction will slow it don while oxygenating the brain via other ways 

And if its ischemic, well oxygenating the patient will not ddo him any harm and may compensate for the ischemia in certain areas 


So, ate least for me, Oxygen is the way to go


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## daedalus (Jun 16, 2009)

Ped101 said:


> Personally, i always go with the 15 lpm Oxygen, because if it's hemmorragic the vasocinstriction will slow it don while oxygenating the brain via other ways
> 
> And if its ischemic, well oxygenating the patient will not ddo him any harm and may compensate for the ischemia in certain areas
> 
> ...



Wrong. This is what you were taught, where? EMT school? Along with the whopping full two hours of anatomy.



> Stroke: The brain is very vulnerable to the effects of oxidative stress. The brain has fewer antioxidants than other tissues. Thus, should we give oxygen to non-hypoxic stroke patients? Studies have shown that patients with mild-moderate strokes have improved mortality when they receive room air instead of high-concentration oxygen.
> The data on patients with severe strokes is less clear.(5) Current research indicates that supplemental oxygen should not be routinely given to patients with stroke and can, in some cases, be detrimental.(6)



http://www.jems.com:80/news_and_articles/columns/Bledsoe/the_oxygen_myth.html


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## VentMedic (Jun 16, 2009)

Ped101 said:


> Personally, i always go with the 15 lpm Oxygen, because if it's hemmorragic the vasocinstriction will slow it don while oxygenating the brain via other ways


 
How are you producing the vasoconstriction?  Hyperventilation?  Is the patient intubated or are you using a BVM?


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## VentMedic (Jun 16, 2009)

daedalus said:


> http://www.jems.com:80/news_and_articles/columns/Bledsoe/the_oxygen_myth.html


 
In another thread discussed some of the articles referenced and found some of the data was done over a period longer than 24 hours. Short term during the stabiliation period may require a higher FiO2 until other issues are stabilized. As well, another protocol guideline such as sepsis may also require a higher FiO2. So again, one blanket statement does not fit all. But, of course, some of these situations may not be known in prehospital. I have had CCTs EMT(P)s want to switch one of our sepsis protocol patients to a 2 L NC with a lactate of almost 10 while we were still in the resuscitative phase. They kept insisting that was their protocol since the SpO2 monitor said a number greater than 92%. I've also had them want to "tweak" the ventilator for a higher ETCO2 number even after repeated attempts to explain permissive hypercapnea.  Thus, there are different acceptable numbers for different situations.


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## daedalus (Jun 16, 2009)

VentMedic said:


> In another thread discussed some of the articles referenced and found some of the data was done over a period longer than 24 hours.  Short term during the stabiliation period may require a higher FiO2 until other issues are stabilized.  As well, another protocol guideline such as sepsis may also require a higher FiO2.  So again, one blanket statement does not fit all.


No one mentioned a blanket statement.

I said earlier; "Well, I know that in line with the recent research into re-perfusion injuries, I am told that 2-4 LPM via Nasal Cannula is most appropriate unless the patient is systemically hypoxic"

And the article I referenced, Bledsoe says:


> The goal of therapy is to avoid hypoxia and hyperoxia. If the patient’s oxygen saturation and ventilation are adequate, supplemental oxygen is probably not required. If the patient is hypoxic or hypercapnic, then you must determine whether the problem can be remedied through increased ventilation, increased oxygenation, or both. Thus, you have to assess the problem, recognize and understand the pathophysiological processes involved, plan an appropriate therapy (within the scope of your protocols), and provide the needed therapy. That is what prehospital care is all about.


So where did you get the idea I was promoting blanket statements? I only see critical thinking being promoted here...


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## VentMedic (Jun 16, 2009)

daedalus said:


> No one mentioned a blanket statement.
> 
> I said earlier; "Well, I know that in line with the recent research into re-perfusion injuries, I am told that 2-4 LPM via Nasal Cannula is most appropriate unless the patient is systemically hypoxic"
> 
> ...


 
I didn't quote *you* directly. I was quoting the JEMS article.  It makes generalities while some of the articles cited don't alway pertain to the acute few hours.


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## daedalus (Jun 16, 2009)

VentMedic said:


> I didn't quote *you* directly. I was quoting the JEMS article.  It makes generalities while some of the articles cited don't alway pertain to the acute few hours.



I see what you meant now. As far as septic shock, it is not mentioned in the article. I am understanding that septic patients do require higher oxygen concentrations?


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## VentMedic (Jun 16, 2009)

daedalus said:


> I see what you meant now. As far as septic shock, it is not mentioned in the article. I am understanding that septic patients do require higher oxygen concentrations?


 
For sepsis patients we monitor SjvO2. Read up on that area.   I think you'll find it very useful.  Also, the principles of HBO and its use for Strokes is interesting.

We usually just run the protocol as far as the O2 is concerned until the lactate is less than 4 or is declining significantly and the MAP of the BP is stabilized. We will try to get off the O2 clock within 24 hours.


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## daedalus (Jun 16, 2009)

VentMedic said:


> For sepsis patients we monitor SjvO2. Read up on that area.   I think you'll find it very useful.  Also, the principles of HBO and its use for Strokes is interesting.
> 
> We usually just run the protocol as far as the O2 is concerned until the lactate is less than 4 or is declining significantly and the MAP of the BP is stabilized. We will try to get off the O2 clock within 24 hours.



I will, thank you.


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## ResTech (Jun 16, 2009)

I think the most important thing to keep in mind is that pre-hospital care of the CVA patient is primarily supportive and O2 via N/C is most often sufficient in the majority of cases. If the patient is not exhibiting signs of systemic hypoxia I personally would not administer O2 by NRB. Would a NRB make a difference in clinical outcome? Prob not.  

As Vent said and was ingrained in our airway class.... hyperoxygenation is what your aiming for and not hyperventilation unless signs of herniation then the last ditch effort is to hyperventilate to mitigate the increased ICP as much as possible. They're is a distinct difference with significant consequence of hyperventilation.


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## emtjack02 (Jun 17, 2009)

Interestingly enough...well to me I just went an inservice on stroke this weekend.  One of the ideas a presenter brought up was a medic directed stroke code.  What this did was when a pt was stroke positive by a designated prehospital scale that they called a stroke code and they actually bypassed the ED and went straight to CT.  Has anyone heard, done, seen this?
OP: I agree with the idea 2L NC probably a good bet.  We unfortunately did not cover this question in the lecture.


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## daedalus (Jun 17, 2009)

emtjack02 said:


> Interestingly enough...well to me I just went an inservice on stroke this weekend.  One of the ideas a presenter brought up was a medic directed stroke code.  What this did was when a pt was stroke positive by a designated prehospital scale that they called a stroke code and they actually bypassed the ED and went straight to CT.  Has anyone heard, done, seen this?
> OP: I agree with the idea 2L NC probably a good bet.  We unfortunately did not cover this question in the lecture.



Pretty routine around here..


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## akflightmedic (Jun 17, 2009)

emtjack02 said:


> Interestingly enough...well to me I just went an inservice on stroke this weekend.  One of the ideas a presenter brought up was a medic directed stroke code.  What this did was when a pt was stroke positive by a designated prehospital scale that they called a stroke code and they actually bypassed the ED and went straight to CT.  Has anyone heard, done, seen this?
> OP: I agree with the idea 2L NC probably a good bet.  We unfortunately did not cover this question in the lecture.



Routine in Florida as well.

We have Trauma Alert and we have Stroke Alert.
Activation by the paramedic alerts those specialty teams to prepare or to start clearing the CT patients in order to receive this one.


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## Melclin (Jun 17, 2009)

Vent: Awesome tutorial. No BS and to the point. Thanks mate.


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## VentMedic (Jun 18, 2009)

Melclin said:


> Vent: Awesome tutorial. No BS and to the point. Thanks mate.


 
The information for ventilation/ventilators, sepsis and shock are pretty decent also on  CCM tutorials.


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