Shock questions

[dac534]

Hello. I am new to the forum and have some questions. I am in EMT school and we are talking about shock and fluid replacement. I have read and read the powerpoints but still don't get some of the materials. So, I know some of the questions are kindergarten to you all but Im still trying to learn so sorry about that.

So here is my questions,

Catecholamines: what affect do the have on the body? Do they just transmit signals to various receptors? And what chemicals are catecholamines?

Hypo, hyer and isotonic solutions: My teacher was explaining them and he lost me where hypotonic solutions should be used when your dehydrated. I thought the exact opposite. So please start from step 1 on that.

Again, I know this is all small stuff but of all the things I don't get it has to be the small stuff I don't understand. I really appreciate you taking teh time to read and respond to this!

 

[CondeEMT]

In the human body, the most abundant catecholamines are epinephrine (adrenaline), norepinephrine (noradrenaline) also dopamine, all of which are produced from phenylalanine and tyrosine. Release of the hormones epinephrine and norepinephrine from the adrenal medulla of the adrenal glands is part of the fight-or-flight response. Catechol or epinehrine. -Wikipedia.

SMH!!!

I am studying shock in my class right now tho i had to google catecholamines because i could not find it,not even in the texts index tho i know what ephiphrine can be a good thing for the body overall to maintain stasis in cases of anaphylactic shock.


What book are you using?

 

[CondeEMT]

I am studying from the AAOS 10th edition. or Orange Book.

 

[Cup of Joe]

I think these are a little advanced for EMT (especially because we don't carry hypotonic solutions on the ambulances here), but I'm in a good mood today, and feel like helping.

Catecholamines: what affect do the have on the body? Do they just transmit signals to various receptors? And what chemicals are catecholamines?

Catecholamines are simply a group of bodily hormones that all share a particular chemical make up (amino groups, hydroxyl group, etc). These act as neurotransmitters, usually triggering the sympathetic nervous system (fight or flight response).

Hypo, hyer and isotonic solutions: My teacher was explaining them and he lost me where hypotonic solutions should be used when your dehydrated. I thought the exact opposite. So please start from step 1 on that.

Hypo usually means "lower" or "below", right? So a hypotonic solution is a solution that has less solute than the fluid around it (or on the other side of a membrane). An example is 0.45% Sodium Chloride (Half Normal Saline).

Isotonic is simply the same amount of solute dissolved in it as the fluid on the other side of a membrane of the fluid around it. An example is 0.9% Sodium Chloride (Normal Saline)

Hyper means "higher" or "above", so a hypertonic solution has a higher solute concentration than the fluid around it.

In dehydration, the blood becomes more concentrated because of the lower than normal amounts of water, the body "pulls" water into the blood from interstitial fluids. Half normal saline is given and travels throughout the body, and osmosis causes the fluid to leave the blood stream and enter the interstitial fluids (replenishing it). Half normal saline is using osmosis to replenish these extravascular fluids more quickly, as compared to using normal saline.

Hope that made some sense.

 

[silver]

Catecholamines are simply a group of bodily hormones that all share a particular chemical make up (amino groups, hydroxyl group, etc). These act as neurotransmitters, usually triggering the sympathetic nervous system (fight or flight response).

Be careful with your terminology here. Catecholamines act as a neurotransmitters and hormones. The fight or flight response, or classically known as the sympatho-adrenal response, is more the result of the release of catecholamines from the adrenal medulla. Sympathetic neurons synapse at the adrenal glands.

Acting as a traditional hormone, epinephrine and norepi are secreted and floods the body. Adrenergic receptors on target tissue bind the epinephrine/norepi. This generally causes vasoconstriction, increased respiratory rate, and glucose and fatty acid mobilization. There are also a lot of other complexities that aren't worth mentioning.

Edit:
to add this is a very simplified way, but it points out the traditional hormonal action in acute stress response.

 

[Brandon O]

Hypo, hyer and isotonic solutions: My teacher was explaining them and he lost me where hypotonic solutions should be used when your dehydrated. I thought the exact opposite. So please start from step 1 on that.

Great questions.

The idea here is, where will the fluid go? Fluid tends to follow solutes. If we add hypertonic solution to the intravascular space (e.g. mannitol into an IV), we're adding more solutes than solvent, and it will tend to draw fluid out of the other spaces to compensate. In other words, it'll dehydrate cells and tissues, which the opposite of what we want.

Conversely, adding hypotonic solution to the intravascular space (e.g. D5W into an IV) adds more solvent than solutes. So the fluid will tend to move out of the bloodstream into the cells and tissues, where dissolved solutes are at a higher concentration, in order to achieve equilibrium. So we're rehydrating the tissues that are dehydrated.

Imagine if we lost blood, however, and wanted to replace intravascular volume. Hypotonic D5W would be a terrible choice, because most of that volume would quickly leave the intravascular circulation.

Think about where you want the fluid to go. This idea is called the "volume of distribution."

Keep scratching your noodle, these are great questions.

 

[VFlutter]

To keep it simple cathecholamines (Epi) increase heart rate, vasoconstrict, and broncodilate. In relation to shock it is a compensatory mechanism to maintain homeostasis. So in anaphylaxis the primary problems are bronchospam and vasodilation. Epi works to conteract the process to maintain an adequate blood pressure and airway. In hemorrhagic shock there is a decrease in blood volume so the body uses Epi to vasoconstrict, which brings more blood back to the heart and vital organs, and increases the heart rate which increases cardiac output to make up for the loss in volume.

That is totally oversimplified but as a Basic there really isn't any point for going into the details. Until you have taken a biology or patho class you will be lost.


On a somewhat related side note. One of my patients this week had a pheochromocytoma. Cathecholamine surge = crazy hypertension

 

[dac534]

First of all, thank you to everyone who has posted. Its really helping me understand this. So I am going to try and explain it teh best way i can and you all can tell me if I am right.

Catecholimines are just norepi and epi. Correct? If that was the case, I was sitting here reading the same slide over a hundred thousand times. I knew exactly what norepi and epi is. So pretty much Epi/nor epi is Catecholimine. Catecholimine is Epi/nor epi. And so all the catechoimines do are: bronchodialtion, increased heart rate, increased respiratory.... pretty much "fight or flight". If I am wrong please stop me and explain where.

And the solutions, a solute will disolve a solvent. A solvent is what a solute will disolve. Correct? So, the hypertonic solution will hydrate cells by taking liquid from more hydrated cells and moving them to a lesser hydrated cell. Hypotonic will take water from the actual blood stream itself and give it to the cells. Isontic im still confused on. Im sorry got being so dang complicated but I need to try and understand this.


I don't know how your alls classificatipons of EMT levels are, but I am in TN and we still have the First Responder, basic, IV tech and EMT paramedic. SO I am trying to be an IV tech. My protocols are allowing me to give 9 drugs(10 including oxygen).Like I said I am probably repeating myself but I don't know how your states classifications are but incase you didnt know I went ahead and explained it. Again, thanks for all the help and taking your time to explain to me all this stuff. Its really helping me to get the big picture.

 

[VFlutter]

And Dopamine. Also don't forget vasoconstriction. Those are the big 3 but they also have other sympathetic effects such as pupil dilaton and sweat secretion. So basically the "fight"

 

[Veneficus]

Just so you know, you are not asking questions about shock.

You are asking questions about vascular tone and volume.

That is 1/3 of 1/2 of shock.

The fluid dynamics you are asking about does not go from more hydrated cells to less hydrated cells.

It moves from either:

intravascular to extracellular to intracellular

or

intracellular to extracellular to intravascular


Isotonic hopefully maintains no net movement of water.

I strongly urge you to pick up a copy of of Guyton's Medical Physiology. That book is written as if the reader understands nothing and it goes step by step through the processes.

I think you will have more success with that.

 

[Brandon O]

First of all, thank you to everyone who has posted. Its really helping me understand this. So I am going to try and explain it teh best way i can and you all can tell me if I am right.

Catecholimines are just norepi and epi. Correct? If that was the case, I was sitting here reading the same slide over a hundred thousand times. I knew exactly what norepi and epi is. So pretty much Epi/nor epi is Catecholimine. Catecholimine is Epi/nor epi. And so all the catechoimines do are: bronchodialtion, increased heart rate, increased respiratory.... pretty much "fight or flight". If I am wrong please stop me and explain where.

And the solutions, a solute will disolve a solvent. A solvent is what a solute will disolve. Correct? So, the hypertonic solution will hydrate cells by taking liquid from more hydrated cells and moving them to a lesser hydrated cell. Hypotonic will take water from the actual blood stream itself and give it to the cells. Isontic im still confused on. Im sorry got being so dang complicated but I need to try and understand this.

Have you taken a chemistry or biology class that describes diffusion and osmosis? If not you're going to have a difficult time with this. You're essentially asking questions that go to the underlying principles involved. I don't mind trying to give a "Sparknotes" summary, but you'd be better off going back to the foundational material (or reviewing it, if you've learned it before).

The catecholamines are essentially epi, norepi, and dopamine. (The first two are also referred to with the term "adrenergic.") They're hormones, so they're released into the bloodstream and hit all the organs and tissues. But they do different things at each location. The different effects are caused by different receptors within, for instance, your lungs and your skin. So as they hit the lungs, they cause the smooth muscles to relax -- bronchodilation. But as they hit the skin, they cause smooth muscle to constrict -- vasoconstriction. Same hormones, different receptors.

The catecholamine response is part of the sympathetic system, which is perfectly sensible to think of as the "fight or flight" response. The opposite is the parasympathetic response, which mostly uses acetylcholine -- the "rest and digest" effect. You can get pretty far trying to predict the effects of each on a certain organ system, based on the "would this help me battle a wooly mammoth, or chill out afterwards?" approach, but some of the effects aren't intuitive. Here's a summary:

As for fluids: you have a few things off. Something dissolved in something is called a SOLUTION. The SOLVENT dissolves the SOLUTE, or the SOLUTE is dissolved into the SOLVENT. So water might be the solvent and sodium chloride (NaCl) might be the solute, making a solution of saline.

If I farted in the corner of your room right now, the fart (solute) would not stay in the same spot of the room's air (solvent). It's high concentration there, and low concentration where you are. So it would gradually spread out until it was at the same concentration throughout the room. This is called diffusion.

The same thing happens in liquids. If you drop that NaCl into some water, it will gradually diffuse through it until it's at equilibrium (all the same). This is just a natural effect due to the random movement of particles.

If you placed a membrane across the water, one that allowed for particles of water and/or NaCl to cross it, this process would still occur. As long as the concentration on both sides is different, NaCl and water will diffuse in opposite directions across the membrane; where there's more NaCl, it'll move across to where there's less, and where there's more water, it'll move the opposite way. The side with more solute (NaCl) is hypertonic, the side with less solute is hypotonic; if they're equal, they're both isotonic. These terms are relative, so they only have meaning when compared to something. When we say an IV solution is hypertonic, we mean compared to the fluid in a normal human body.

The important point is that water tends to follow solutes; it moves toward areas of high concentration in order to dilute them and achieve equilibrium. In the above example, the solute itself also diffused the opposite way, and this happens in the body too, but water is usually much more mobile. The "membrane" in the body is the walls of the blood vessels, the plasma membrane of the cells, etc.

So a hypertonic solution has more solute (stuff) than the solution that's inside your cells. We add it to your blood. Since your blood is now more concentrated than your cell contents, water will move out of the cells and into the blood. The cell is now dehydrated and your blood volume is increased. If we'd added a hypotonic solution, the opposite effect would occur; water would move out of the blood and into the cells to chase the higher concentration of solutes there.

This is a seriously :censored::censored::censored::censored::censored::censored::censored:ized explanation, and I'm trying to decide what to elucidate and what to leave out, but hopefully it makes some sense.

 

[silver]

Have you taken a chemistry or biology class that describes diffusion and osmosis? If not you're going to have a difficult time with this. You're essentially asking questions that go to the underlying principles involved. I don't mind trying to give a "Sparknotes" summary, but you'd be better off going back to the foundational material (or reviewing it, if you've learned it before).

The catecholamines are essentially epi, norepi, and dopamine. (The first two are also referred to with the term "adrenergic.") They're hormones, so they're released into the bloodstream and hit all the organs and tissues. But they do different things at each location. The different effects are caused by different receptors within, for instance, your lungs and your skin. So as they hit the lungs, they cause the smooth muscles to relax -- bronchodilation. But as they hit the skin, they cause smooth muscle to constrict -- vasoconstriction. Same hormones, different receptors.

The catecholamine response is part of the sympathetic system, which is perfectly sensible to think of as the "fight or flight" response. The opposite is the parasympathetic response, which mostly uses acetylcholine -- the "rest and digest" effect. You can get pretty far trying to predict the effects of each on a certain organ system, based on the "would this help me battle a wooly mammoth, or chill out afterwards?" approach, but some of the effects aren't intuitive. Here's a summary:

As for fluids: you have a few things off. Something dissolved in something is called a SOLUTION. The SOLVENT dissolves the SOLUTE, or the SOLUTE is dissolved into the SOLVENT. So water might be the solvent and sodium chloride (NaCl) might be the solute, making a solution of saline.

If I farted in the corner of your room right now, the fart (solute) would not stay in the same spot of the room's air (solvent). It's high concentration there, and low concentration where you are. So it would gradually spread out until it was at the same concentration throughout the room. This is called diffusion.

The same thing happens in liquids. If you drop that NaCl into some water, it will gradually diffuse through it until it's at equilibrium (all the same). This is just a natural effect due to the random movement of particles.

If you placed a membrane across the water, one that allowed for particles of water and/or NaCl to cross it, this process would still occur. As long as the concentration on both sides is different, NaCl and water will diffuse in opposite directions across the membrane; where there's more NaCl, it'll move across to where there's less, and where there's more water, it'll move the opposite way. The side with more solute (NaCl) is hypertonic, the side with less solute is hypotonic; if they're equal, they're both isotonic. These terms are relative, so they only have meaning when compared to something. When we say an IV solution is hypertonic, we mean compared to the fluid in a normal human body.

The important point is that water tends to follow solutes; it moves toward areas of high concentration in order to dilute them and achieve equilibrium. In the above example, the solute itself also diffused the opposite way, and this happens in the body too, but water is usually much more mobile. The "membrane" in the body is the walls of the blood vessels, the plasma membrane of the cells, etc.

So a hypertonic solution has more solute (stuff) than the solution that's inside your cells. We add it to your blood. Since your blood is now more concentrated than your cell contents, water will move out of the cells and into the blood. The cell is now dehydrated and your blood volume is increased. If we'd added a hypotonic solution, the opposite effect would occur; water would move out of the blood and into the cells to chase the higher concentration of solutes there.

This is a seriously :censored::censored::censored::censored::censored::censored::censored:ized explanation, and I'm trying to decide what to elucidate and what to leave out, but hopefully it makes some sense.

Some things should be clarified here. In general, Na and Cl ions will not go across the membrane into the cells very much. This is what causes the driving force for water to move in and out.

To add what you said:
Essentially there is are solutes on each side that can't more or less can't go across. At all times the membrane will try to balance the overall concentration of solutes by letting water move across. The variable once balanced will be the volume of water. If you have a higher concentration of solutes on one side, water will flow to that until both concentrations are the same.

 

[dac534]

I think after reading this over the fourth time something clicked for me. Here is how I am picturing this in my mind. I know its kind of kindergartenish but for some reason I was just not getting this. "salt and taxis". Ok. So, we have our blood vessel. We have our cell. The cells have got a whole bunch of salt in it. The blood vessels are hypotonic so therefore the taxi(water) is going to move to the cell to deliver the salt to where it needs to go. Our cell is filled with salt, so we are dehydrating that cell by taking salt out and equalizing the salt content of the vessel and the cell. Running .45 NS would do this. Homeostasis. There is our hypotonic solution.

Hypertonic exact opposite. blood vessel has more salt in it, the cells need rehydrated. So the taxi(water) is going to bring the salt into the cell so there will be an equal concentration in both the cell and vessel. So now if we have equal(homeostatic) concentrations, we are just fine and dandy. Have our cake and eat it too. Run some NS and we are having a great day. I think part of what was throwing me off was I think my teacher had the exact opposite of what you all was explaining. And I quote" Solvent- a substance in which a solute will dissolve. Solute a substance that dissolves a solute". That sounds completely bass akwards to me. But he could have been in a hurry. So, could you all please tell me if my small brain has finally comprehended this?

I feel pretty dumb, seriously after taking that long to try and figure this out. When I took chemistry I had a 95 at least average. I used to teach people, help with homework all that good stuff. What happened I don't know. I am hoping I got this all right now. That would be alot of weight off my shoulders for our test Monday.

 

[dac534]

So osmosis occurs 99.9% of the time? The content is pretty much the same in the cell and the vessel. BUT where salt goes water follows, if there is no water in a cell, the water will move into the cell to make it homeostatic. Is that what you are saying?

 

[silver]

So osmosis occurs 99.9% of the time? The content is pretty much the same in the cell and the vessel. BUT where salt goes water follows, if there is no water in a cell, the water will move into the cell to make it homeostatic. Is that what you are saying?

The saying "where salt goes water follows" isn't literal in this sense.

Okay so lets generalize and simplify this.
-When we say blood, we mean anything outside of a cell.
-The major components, solutes, outside of the cell and inside the cell are different. Generally speaking Na and Cl like being on the outside and K and PO4 on inside.
-The overall concentration of components of things that can't go through the membrane easily (osmolarity) will always try to equal itself. Thus creating a drive for water to move (osmotic pressure) to make sure this concentration equals each other.

So lets say the concentration when you start is 100 on both sides, balanced. You add hypertonic (meaning has a higher osmolarity than your reference) solution to the outside of cells, blood. Theoretically this makes the outside 104. The inside is 100. The solutes can't go through the membrane...so what needs to happen? Water has to go where the higher concentration is. Lets say it balances it at 102 (higher than starting as we added hypertonic). Inside the cells will have less water now though as it left. And the reverse is true when you add hypotonic.

Its hard to explain the concepts without any of the meaty stuff. Understanding osmolarity and osmotic pressure may be a good place to start.

 

[hogwiley]

Im surprised this is something covered in EMT school. Its not like youre going to be giving IV fluids. Of course it probably doesnt hurt to know this stuff as it might help you decide when ALS should get involved.

My EMT class didnt cover any of this stuff. It wasnt until I took an A&P class at a community college that I was forced to think about things I learned years ago in high school chemistry.

 

[Veneficus]

Im surprised this is something covered in EMT school. Its not like youre going to be giving IV fluids. Of course it probably doesnt hurt to know this stuff as it might help you decide when ALS should get involved.

My EMT class didnt cover any of this stuff. It wasnt until I took an A&P class at a community college that I was forced to think about things I learned years ago in high school chemistry.

There has been a considerable basic science element added to EMT Basic in the national curriculum.

PH balance also needs to be taught.

As I have said many times, the problem is most of the instructors do not understand this material because they became instructors after X years of field experience, not X credit hours of science education.

The EMS textbook publishers have exacerbated this problem by coming up with disconjoined bullet points and "spark's notes" for teaching material to market.

So it is often presented as disconjoined facts to memorize instead of cohesive understanding.

What you see in this thread is the result.

It stands to reason if many high schools where I am from teach basic chemistry in 10th grade and your EMS text (Basic EMT) is written at 8th grade, there is going to be a problem like this. Especially if your teacher just memorized a bunch of bullet points.

It is part of the reason I suggested a text that would help instead of trying to teach basic chemistry over an online forum.

I like to help, bu thtere has to be a basic understanding to help. Given the most basic errors presented here, it is my guess the problem is this topic was not properly taught to the poster.

If you really want to help, it will have to go back to the beginning. "This is an atom, This is an ion" level stuff.

I would also like to add to the explanation, solubility is not random it takes a certain amount of solvent to seperate each particle of solute especially in water, it is a constant motion in order to accomodate as much as possible.

I think one of the biggest problems in teaching medicine is the idea of teaching it as static events.

One of my best professors likes to say "The human organism is a chemical reaction in a watery medium." (He is a biochemist can you tell?)

Anyway, as I said, consult Guyton's, that will help the most.

 

[Brandon O]

Thanks for tagging in silver.

dac, go with his model. The key factor here isn't the movement of salt (which occurs, but not much, and isn't what you're interested in anyway). It's the movement of water. When there's more water and less solute, water moves to the other side until concentrations are equal. So we can manipulate the concentration of whatever we're giving in order to control which direction we want the water to move.

 

[VFlutter]

If you go on YouTube there is a channel called InteractiveBiology that may help you understand some of these concepts.

 

[NYMedic828]

If you go on YouTube there is a channel called InteractiveBiology that may help you understand some of these concepts.

+1. That channel is fantastic.

There has been a considerable basic science element added to EMT Basic in the national curriculum.

PH balance also needs to be taught.

As I have said many times, the problem is most of the instructors do not understand this material because they became instructors after X years of field experience, not X credit hours of science education.

The EMS textbook publishers have exacerbated this problem by coming up with disconjoined bullet points and "spark's notes" for teaching material to market.

So it is often presented as disconjoined facts to memorize instead of cohesive understanding.

What you see in this thread is the result.

It stands to reason if many high schools where I am from teach basic chemistry in 10th grade and your EMS text (Basic EMT) is written at 8th grade, there is going to be a problem like this. Especially if your teacher just memorized a bunch of bullet points.

It is part of the reason I suggested a text that would help instead of trying to teach basic chemistry over an online forum.

I like to help, bu thtere has to be a basic understanding to help. Given the most basic errors presented here, it is my guess the problem is this topic was not properly taught to the poster.

If you really want to help, it will have to go back to the beginning. "This is an atom, This is an ion" level stuff.

.

We will never surpass this level we are at now unless we remove the vocational factor of EMS. (But im just agreeing with you)

You don't expect an electrician to understand physics. How can anyone expect an EMS provider to understand physiology.

Other emergency professions such as police officer and firefighters are perfectly fine being vocational because the tasks they perform can not truly be taught in a classroom. It needs to be learned by experience. Medicine is a science and needs to be learned in a classroom and furthered with experience. We do it the complete opposite.