Racemic epi in allergic reaction

[DwayneEMTP]

You might be right about that, though I'm not sure how much rate figures into the equation. Maybe a lot, but I don't know.

And my thought, if we were going to define this condition as shock, which I'm not sure is accurate at this point, would be decompensated, as her pressure should be more elevated if she was still compensating, right?

I'm a little bit surprised that I'm the only one making the argument for her blood pressure not being elevated. If we expect, based on her condition, for her blood pressure to be significantly elevated, yet instead find her to be normotensive, then that would actually be a relative hypotension, wouldn't it?

I think that my thinking is much less sophisticated than yours. For me the elevated heart rate, plus the elevated respiration rate, can't possibly, in my experience be associated with a calm patient and in fact I'm confident is going to be associated with a patient that freaking out.

This freaking out is going to cause a catecholamine release, one of the effects of this release is going to be vascular constriction, which, in my little mind should lead to an increase in blood pressure.

When I don't see this increase in blood pressure then I assume that something is retarding it. In my experience that 'something' is going to be either physiological, or pharmaceutical. So I immediately begin looking to solve one of those problems, or both, with further investigation. Of course there's always the chance that unusually low b/p is normal for her. But those aren't really very good odds to play in a patient this severe.

So if I assume that this 6 year old isn't likely on any type of pressure controlling meds, then an allergic reaction, in the context of this made up scenario, makes more sense to me than an asthma attack. See?

Like I said, not terribly sophisticated thinking. Many here, like you likely, could go into it in much more depth and probably use many calculations, but that's what I've got Brother....

Thanks for your response!

[DFIB]

I tend to think the same as you Dwayne except I am still learning all the formulas and am not near as sophisticated as you. Funny how that woks out eh? At my level understanding physiology in the key.

I would treat this as compensated shock and roll. Get it? Shock and Roll? Ahh, never mind. But it will not be the first time I was in the ditch with a diagnosis/treatment.

[DwayneEMTP]

As above DFIB, what would cause you to believe that this child is compensating instead of decompensating?

Unless of course the entire sentence was part of your pun, in which case...shame on you! It was terrible! (But I did get it...)

[DFIB]

The relationship between compensated and decompensated shock is that where the first ends the other begins. Isn't that simple? I am about to defeat my own argument but will try not to.

I think you are absolutely correct in asserting that a patient is decompensating when they have diminishing BP, Tachycardia and tachypnea and the other symptoms that accompany this clinical picture. I would not consider her decompensated until she reaches the threshold of orthostatic pressure changes, BP bellow the threshold, altered Mental Status, dry mucosa and the other signs and symptoms of decompensated shock. I don't think we are falling into a game of semantics. This is why I called it compensated shock.

In order to get decompensation the patient would have to be decompensating even though they are considered in compensated shock.

You know I think you might have a point. So why do we call it compensated shock if they are obviously decompensating?

By definition compensated shock is non-progressive and decompensated shock is progressive. So why are the thresholds there? I would think that the thresholds exist to mark the stage where perfusion drops to an unacceptable level.

I bet that makes no sense at all to anyone but me. I am not real sure that I get it either. Darn.

Edited July 25, 2012 by DFIB

[chbare]

Shock involves a constellation of issues and is not simply quantified by a blood pressure. If we can agree on this issue, then I think we can possibly move foreword.

[DFIB]

Shock involves a constellation of issues and is not simply quantified by a blood pressure. If we can agree on this issue, then I think we can possibly move foreword.

I most definitely agree. That last post was kinda of a one issue disorganized post.

Are you going to move us forward? I will love to read it!

[DwayneEMTP]

We certainly agree that shock is relevant and diagnosed based on more than a b/p. I tried to be clear about that in my postings.

DFIB, I see your point and agree. I'm not sure that I've ever looked at a patient and thought, "Hell, they've decompensated." But instead felt that they were compensating, or decompensating (within the context of the discussion).

In my mind they are either compensating for things that I can detect that I feel would need to be compensated for, meaning that they are not presenting the clinical picture that I expect based on assessment...The left, level and then upslope side of the graph...

Or the compensation had occurred and was slowly/quickly failing, the right, downslope side of the graph beginning from the peak compensation/compensation failure point.. I guess I've always just called the decompensated right side level ground, "Oh shit."

Thanks for your input...And Chbare, yeah, this seems like an awesome time for you to step in when you have time...

[runswithneedles]

The bug bite and reasonably rapid onset (20 minutes) are the huge clues that this is not an asthma attack.

unfortunately the bug bite was not pointed out until after the scenario. I totally fudged up on my complete physical assessment.

chbare covered the pharmacology which was the root of your question, but I am going to play devils advocate...just because I can.

Based on the formula for normal blood pressure of [(Age x 2) + 90 = 102], and hypotensive being [(Age x 2) + 70 = 82] I am going to argue that she is normotensive. She does not have any hives or angioedema. It sounds like her symptoms are localized to her bronchioles...making me lean away from anaphylaxis.

Her heart rate and her respirations are elevated which should be expected from her respiratory distress. She has a history of asthma but no history of allergies (other than seasonal -- does anyone know if there is a correlation between these and anaphylactoid reactions?)

You said that she had a "bug bite" which I take to mean something entirely different from a HYMENOPTERA STING. One of which is a leading cause of anaphylaxis, the other I don't believe carries such a risk.

In terms of the contrast in onset between asthma and anaphylaxis...well...I can't quite come up with an argument for that. But I think my case still stands.

So I'm going to say that your working diagnosis wasn't as wrong as your instructor may have suggested, even though he had the "answer" in his hands and had the advantage of building things around it. Now I ask you...so she was maxed out on albuterol, but what other medication could you have given that has a mechanism of action that is still pretty specific to the bronchioles?

Dexamethasone wouldve been another good one for this patient.

[mobey]

Dwayne: I will indulge as devil's advocate. (Sorry chbare)

When looking at a bp as a make or brake on diagnosis (don't defend yourself here... just being general) I think it is important to take it to the next level.

If systolic is a representation of LV output and Diastolic is a representation of vascular resistance, we can put this into better context.

Typically, a low systolic is a result of poor preload, or poor LV function.

Typically a low diastolic is representative of poor vascular tone.

So in this patient we see a slightly low systolic, and perhaps a lack of hypertension.

It can be argued that this could be a result of poor preload, as a direct result of hypovolemia caused by the tachypnea.

With the diastolic of 75 we could accept that her vascular tone is intact and working normally, which does not fit with the vasodilation caused by histamine in anaphylaxis..

[DwayneEMTP]

Shit..

I need to think for a minute....