 Hi, welcome to Nursing School Explained and this video on hypertonic IV fluids or solutions. Before we jump into looking into the details, let's review some basic principles that will help you better understand the physiology and what we're actually looking at with patient care. So if we look at the basic principles here, first of all there are certain fluid compartments. We have the intracellular fluid, which is inside the cell, and then we have the extracellular fluid, which are all the fluid compartments outside the cell. And the extracellular fluid is comprised of two different parts, which is the intravascular space as well as the interstitial space. And the interstitial space is the space between the intravascular and the intracellular fluid, where fluids move by osmosis back and forth and then particles move by diffusion. So when we look at fluid shifts in IV fluid administration, we're always only looking at osmosis because we give the patient fluids and that's what's going to cause fluid shifts if we give hyper or hypotonic solutions. And so osmosis only pertains to water shifting. So think about osmosis as H2O. And if we look at this in a beaker here with a semipermeable membrane that basically represents the cell membrane, our body always strives for equilibrium for homeostasis. And in this case on the left side here we have a higher concentration of particles and less water. And on the right side we have a lower concentration of particles and more water. So when we look at osmosis the water is going to shift from the higher concentration on the right to the lower concentration on the left trying to equalize these two fluid compartments. And so the fluid moves from a higher to a lower concentration and the H2O osmosis water moves. And here we have the normal serum osmolarity which is the concentration of particles in a fluid and in the serum that means the particles that are in our blood, in our blood vessels. And that is 275 to 295 milliosmos per liter and depending on what our osmolarities were either hydrated or dehydrated or were just normal in this case with normal concentrations of solutes. So how does this fluid shift and osmosis apply to IV solutions? So again here we have our blood vessel and then the cell. And we can only administer fluids in the intravascular space. So now if we give the patient hypertonic IV solutions meaning that they are more concentrated than the serum and then like we talked about here the body is going to try and shift and put this into equilibrium. So it's going to pour water out of the cells into that intravascular space and then get rid of it by diureasing it out. So in hypertonic solutions a fluid shifts out of the cell from that intracircular into the intravascular space. If you want a little bit more details on this principle I have two videos that go more into the diffusion and osmosis and the different explanations on how that works into more dips. So for hypertonic IV solutions like again they cause fluid or water to shift out of the cell. Now when do we use them? So number one cause is if there's hyponatremia a very low sodium level and we'll talk about this here in a moment. The other use is when there is head trauma or cerebral edema or which equals increased intracranial pressure because when the cells are swollen there's a lot of edema a lot of extra water in the cerebral cell that we want to move out because most likely with cerebral edema the patient has changes in levels of consciousness. They might have behavior issues they might be agitated and so we want to decrease the pressure in those cerebral cells by giving them intravascular hypotonic solution the water is going to shift out of the cells hopefully making the patient's head injury better or less symptomatic. And so solutions that we use that are hypotonic is 3% sodium chloride. You probably recall that normal saline or isotonic saline is 0.9% so this is greater than 3 times that percentage or concentration and therefore it is a hypotonic solution. So now when there's hyponatremia when there is less or low sodium in the serum we give the patient a higher concentration of sodium to balance that out. Another solution that is hypotonic is D10 which is dextrose 10% and this is commonly used in patients who receive parenteral nutrition so through the IV because for some reason their GI system is not allowing them to absorb nutrients and D10 is something that we use in case the parenteral solution runs out that we use very temporarily until we can get the next TPN going to make sure that the patient's blood sugar level doesn't drop but that is a hypotonic solution and we need to make sure that we check although the appropriate things with that that we'll discuss in a moment. And then a couple of other solutions that include D5 which is 5% dextrose so D5 0.9% sodium chloride as well as D5 lactated ringer solution. And the special thing with D5 solutions is that in the bag so if you're actually looking at the bag that contains the fluid it is hypotonic because it contains the D5 and the normal saline which by itself the normal saline is just isotonic. Same with D5LR, D5 in addition to lactated ringers which is isotonic in the bag is a hypotonic solution. However, as soon as we start infusing these fluids into the patient's body the D5 is used up because it is a source of nutrition or glucose or dextrose in this case sugar for the body so it's immediately going to be absorbed by the cells so right away as soon as it hits the patient's bloodstream that D5 is used up leaving us with the 0.9% sodium chloride or the LR which then means that in the body it's actually an isotonic solutions because right away we're burning off or we're using up that D5. For nursing considerations for hypertonic IV fluids we always have to check vital signs of blood pressure and heart rate because we're giving them fluids at a certain rate and that's going to cause that fluid shift out of the cells into that intravascular space and whenever we add fluids to the intravascular space we want to see how does that affect their blood pressure and of course heart rate as well. And then we also want to check the patient's lung sounds because they are at risk for fluid volume excess because there's fluid shifts that occur here. We also want to check their sodium levels because we most likely are given this for hyponatremia or if we give it for head trauma if it's a high concentration of sodium chloride we'd certainly want to check the levels to see where we are to make sure we're not tipping them over the point where they now go from hypo to hypernatremia. And then thirdly or lastly this type of solution is always administered at a slow rate and only at the IV pump. So normal IV maintenance fluids such as normal saline or half normal saline hypotonic solutions can be given anywhere from 30 to maybe up to 150 ml per hour depending on the patient's patient situation. This hypotonic solution because it affects the brain as well as their sodium levels because it is so concentrated is usually given only at a slow rate so don't expect that to be more than maybe even 30 ml per hour. If you see an order with 3% sodium chloride at 150 ml an hour then all the red flags should be going off because things might shift really quickly and then bad things can happen as the fluid shifts and the patient might go into fluid overload or it might affect their level of consciousness. So thank you for watching this video on nursing school explained please give me the thumbs up if you've enjoyed it also check out the other videos about hypotonic solutions as well as isotonic solutions and also my videos about fluid volume deficit and excess that you can find in the fluid and electrolyte playlist. Thanks for watching. See you soon.