Tachycardia not always a reliable sign of hypotension

[rhan101277]

I read this article in this months issue of EMS magazine. We are trained heavily on recognizing early symptoms of shock. The main one which is tachycardia. The article states that the absence of tachycardia should not reassure that clinician about the absence of blood loss. Also of concern is that fact that lots of people take beta blockers which inhibit the heart from speeding up.

In studies it was found that 11% of patients had no tachycardia with 750-1,500mL of blood loss and 7% with 1,500 mL or more.

I guess its just safe to keep in the back of your mind, hopefully most people should have tachycardia, if they don't then you will start getting the late signs like lower blood pressure and skin, color, temp changes.

If you try to use a pulse oximeter on someone in profound shock, shouldn't you get a lower dissolved oxygen reading? In which applying oxygen, even though it helps, maybe not be indicated on the monitor.

Anyhow I just thought I would mention this and see what others thought.

 

[Sasha]

You didn't provide a link to the article, love.

 

[rhan101277]

You didn't provide a link to the article, love.

That is because I read it in a paper magazine.

 

[MSDeltaFlt]

I read this article in this months issue of EMS magazine. We are trained heavily on recognizing early symptoms of shock. The main one which is tachycardia. The article states that the absence of tachycardia should not reassure that clinician about the absence of blood loss. Also of concern is that fact that lots of people take beta blockers which inhibit the heart from speeding up.

In studies it was found that 11% of patients had no tachycardia with 750-1,500mL of blood loss and 7% with 1,500 mL or more.

I guess its just safe to keep in the back of your mind, hopefully most people should have tachycardia, if they don't then you will start getting the late signs like lower blood pressure and skin, color, temp changes.

If you try to use a pulse oximeter on someone in profound shock, shouldn't you get a lower dissolved oxygen reading? In which applying oxygen, even though it helps, maybe not be indicated on the monitor.

Anyhow I just thought I would mention this and see what others thought.

In regards to the pulse ox reading, not necessarily so. If your pt has profound shock, odds are they won't have enough of a perfusing blood pressure to get the pulse ox probe to be able to read anything at all.

 

[Veneficus]

I read this article in this months issue of EMS magazine. We are trained heavily on recognizing early symptoms of shock. The main one which is tachycardia. The article states that the absence of tachycardia should not reassure that clinician about the absence of blood loss. Also of concern is that fact that lots of people take beta blockers which inhibit the heart from speeding up.

I find it quite disheartening you had to read this in a magazine and were not taught this specifically in class. Dr. Carol Cunninham led a charge for "geriatric" credentialed trauma centers In Ohio last year or the year before. Apparently there is not enough education on dealing with the complications of geriatrics. But I think these centers were more for the emergency aspect than the surgical aspect of trauma.

I guess its just safe to keep in the back of your mind, hopefully most people should have tachycardia, if they don't then you will start getting the late signs like lower blood pressure and skin, color, temp changes.

I think it is more important to specifically look for injuries. Many people who are compensating for injury may have "normal" or slightly elevated vital signs. Personally I like to fnd exactly what the problems could be and err on the side of a more extreme problem than a simple one. (within reason of course)There are also specific places to check for acute volume loss. Though sometimes signs appear late.

If you try to use a pulse oximeter on someone in profound shock, shouldn't you get a lower dissolved oxygen reading? In which applying oxygen, even though it helps, maybe not be indicated on the monitor.

Anyhow I just thought I would mention this and see what others thought.

Forget about pulse ox. It is a tool that is too heavily relied upon with too many confounding factors. learn to check the mechanical breathing, respiration, and tissue perfusion without it. There seems to be a trend that the machine will tell you all of this as opposed to being a quick monitor of what you already know or suspect.

 

[Ridryder911]

One thing about the new scope/curriculum is that the basic and even MFR will be taught more pathophysiology of shock syndrome.

R/r 911

 

[rhan101277]

I find it quite disheartening you had to read this in a magazine and were not taught this specifically in class. Dr. Carol Cunninham led a charge for "geriatric" credentialed trauma centers In Ohio last year or the year before. Apparently there is not enough education on dealing with the complications of geriatrics. But I think these centers were more for the emergency aspect than the surgical aspect of trauma.



I think it is more important to specifically look for injuries. Many people who are compensating for injury may have "normal" or slightly elevated vital signs. Personally I like to fnd exactly what the problems could be and err on the side of a more extreme problem than a simple one. (within reason of course)There are also specific places to check for acute volume loss. Though sometimes signs appear late.



Forget about pulse ox. It is a tool that is too heavily relied upon with too many confounding factors. learn to check the mechanical breathing, respiration, and tissue perfusion without it. There seems to be a trend that the machine will tell you all of this as opposed to being a quick monitor of what you already know or suspect.

I know what you mean about looking for injuries, but i am just talking about stuff you can't see like internal bleeding. If tachycardia doesn't occur, then the patient may seem to be in decompensated shock. I don't see how blood pressure can't be compensated and stay around normal levels without tachycardia. It may be possible with fluid replacement, but this is something a basic can't do. Of course if you suspect shock, you can go ahead and start treating it. If you think its a bad enough MOI then just go ahead and treat for it if no clinical signs are present.

Like I have said in many posts I think they should increase EMT-Basic to include A&P I and II, which I have already taken. I think the curriculum should be more in depth and also basics should get paid more for that extra knowledge.

I mean look at San Antonio, TX. I just read where they are going to start sending basics on every 911 call. Which means you need to be on your A game, to know what is going on. In fact in concerns me, that is putting people's mortality on the line.

 

[Veneficus]

I don't see how blood pressure can't be compensated and stay around normal levels without tachycardia. It may be possible with fluid replacement, but this is something a basic can't do. Of course if you suspect shock, you can go ahead and start treating it. If you think its a bad enough MOI then just go ahead and treat for it if no clinical signs are present..

Increase left ventricular contractility can increase cardiac output without tachycardia. For example as part of Cushing's triad.

Also consider that if there is malnutrition, increased heart rate may not be possible. The same with hypothermia, where you will see vasoconstriction.

If your high BP is untreated and upper end of normal, heart rate will still show textbook normal BP.

As you mentioned from the article, medications may prohibit an increase in heart rate and contractile strength.

You don't have to have blood leaking out to have hypovolemia. Look at septic shock, anaphylactic shock, or neurogenic shock. You may not see an increase in heart rate in a heat emergency either. (have seen dozens of heart exhausted patients with a HR < 100) who were definately hypovolemic.

fluids also don't have to be given IV. A more austere environment, like the military or at sea may require the use of PO fluids. So do some clinics.

Also, if you haven't heard me say it a million times before. It is CVP that determines preload, not SBP, one has nothing to do with the other. If you rely on SBP one day you will get burned. In the field you are better off using pulse pressure to determine perfusion. It will give you a better picture as to what is going on.

In penetrating injuries, permissive hypotension is shown to be effective. (As of conference last september)

I never treat based on mechanism. Mechanism allows for an index of suspicion which must be thoroughly evaluated. You don't have to be an advanced provider, just really good at assessment. (although the two go hand in hand, they are not mutually exclusive)

 

[rhan101277]

Veneficus thanks for you knowledge as always, I feel good that I have enough knowledge to understand your posts. When I first signed up here, I didn't know anything. I still only know a drop in the bucket if that.