Fluids and Electrolytes

Lomo go to fluids and electrolytes in this section here we're going to talk about some of the body fluids and what they represent and what they're doing in the body and the electrolytes that are going to be present in those fluids and help to maintain some of our body's functions so let's go ahead and get started and take a look at what our fluid intake and output is composed up so there's a number of different ways that we can take fluid in and excrete fluid from the body first of all we can get fluid in in our fluid intake that we're drinking so that's the primary way that we're getting fluid into our bodies through our intake of fluid in our water etc that we're drinking we can also get fluid in by way of IV so an intravenous line would it be another way that we can get fluid into the body we can have float absorption for example through the gut so the person is eating and there's a certain amount of fluid in our food that gets absorbed as well lots of different ways it can be excreted through the skin through the lungs through drainage through the kidney and through the bowel we can all have fluid excreted from the body we'll take a look in a moment at where and how much of that fluid is going out and into some of those different components but first of all let's talk a little bit about what our body fluids and water do in the body they provide transportation of our nutrients to the cells without having blood transporting our nutrients to cells we would not be able to get the nutrients where they belong they would just sit there on the GI tract wouldn't go anywhere they carry waste products away from the cells so the cell produces the waste product and the blood comes to the cell takes the waste product away the waste product then gets excreted from the body by way of the kidneys or maybe by way of the GI tract they provide an environment for electrical or electrolyte chemical reactions to occur so our electrolytes provide chemical reactions that allow the body to have certain functions to produce certain functions and water in their body fluid provide that environment provide that substrate for those electrolyte chemical reactions to occur now this diagram here is showing what our body fluid composition and compartments is we just use that 60 40 20 rule and we say that 60 percent of the body weight is water not mass or not percentage of overall body but body weight 40% of our body weight is in the intracellular fluids 20% is in the extra cellular fluid so here's a distribution of body fluids again our total body water 60% and we have about 2/3 of it in the intracellular fluid about 1/3 of it in the extracellular fluid the intracellular fluid as the name implies means it's in the cell okay there's only one place it can be it can be in the cell however the extracellular fluid could be in the interstitial space or it could be in two intravascular space so two different places we could have fluid we could also have fluid in the lymph system the synovial fluid that our cerebral spinal fluid sweat etcetera all those are different places that we have extra cellular fluid so lots of different places we have extracellular the two big ones are going to be the interstitial area and the intravascular area however two thirds of the greatest majority of the fluid in the patient body is inside the cell now notice these are big numbers here okay about 25 liters about 15 liters now that doesn't mean that we have an overabundance of fluid in the body in fact if we lose about 10 percent of that fluid the patient's going to become terribly symptomatic so what does our fluid intake come from we saw the previous picture that showed a number of different ways we get fluid in and out of the body so let's take a look at the vast majority of our fluid intake comes from water that comes from beverages so you're drinking that beverage and you're getting the vast majority of your water a significant part of our water that we take in it comes from food so there is a certain amount of water that's in a lot of the food that you eat okay so that's going to be 28 percent and then water from metabolism accounts for about 8% so water is the end result of some methods of metabolism and you saw that when we talked about acid-base balance through the carbonic acid equation we produced water so that's another way that we can produce water we can have water intake in a body now that's a very small percentage 8% and that's pretty static so that's not something that's going to go up and down to help to compensate when somebody is gaining or losing fluid on the other hand where does the water go sore fluid output the vast majority 59% is water in the urine so urine output is going to be about fifty nine percent twenty five percent is water evaporated from the skin now this may vary a little bit in different climates if you're a very humid climate there's going to be less evaporation of water from the skin so less loss and a drier climate since the air is drier more fluid more water will evaporate from the skin and that can actually lead to the patient becoming dehydrated quicker because they're losing more fluid from the skin than in normally what next we have water from the lungs you notice that's a fairly significant portion here about eleven percent now this is talking about somebody who is just sitting around breathing normally so as you're sitting here and you're breathing normally well you maybe you're not maybe you're running on a treadmill okay which means we would be breathing faster and the faster you breathe and the deeper you breathe the more water will be released from the lungs and in fact your patient can actually become dehydrated because of a lack of water to are from the lungs and the patient breathing too much out from having hyperventilation we also have about five percent of our water loss coming from feces so as a review to remember this the greatest quantity of body fluids is contained within the blank which is called the blank compartment so the greatest quantity of body fluids is contained within the cells which is called the blank compartment what compartment is that the intra cellular okay within the cells intra cellular all you got to look at is the words in the question they give you the definition so intracellular fluid compartment the second largest fluid compartment is known as the blank compartment it refers to all the fluid outside the cells and in fact that would be okay so it's not intracellular therefore it must be extracellular fluid is outside of the cells the extracellular fluid compartment contains two major compartments which the interstitial and the intravascular our distribution of body fluids is going to change as we age there's going to be different amounts of fluid overall in the body as we age so we start out and as a child and about 80 percent of our body weight is going to be fluid we already said the adult has about 60% and the older adult could have a lot less so take a look at some of these reasons why the aging population is prone to dehydration they have a decreased percentage of total body water we'll look at that in a moment and increase in adipose and a decrease in their muscle mass decrease renal function and a decrease thirst perception so as we go throughout our life you notice that each one of these it's like they're filling the body up with water so the baby's filled up pretty high they're 80 percent of that baby is water now you get to the adult that's only about 60 percent of the adult is water and now we get to the older adult and the older adult we're down into the 45 to 50 range the ramifications of this are that as we age and especially in the elderly they're going to be more prone to developing dehydration and having fluid volume problems so because they're fluid volume is in a lower range normally if that increases they could have problems like heart failure if that decreases then the patient could develop dehydration very easily since they're starting with less fluid to begin with let's flip back to the newborn now the newborn is 80% fluid so wouldn't that make sense they watch is boy the kids 80% fluid they can probably lose a lot of fluid before they would become symptomatic and have problems well not true the newborn is also very prone to fluid loss because so much of the body is made up of fluid even a small change in that fluid could cause the patient to become significantly unstable so let's take a look at some questions here regarding our intra cellular and extracellular compartments and body water so let's take a look at our first one here intracellular body fluid accounts for approximately 40 percent or two-thirds of our total body water what do you think is that true or false well this question here is going to be false well didn't we say that intracellular body fluid accounts for two-thirds of the total body water yes but it's not 40% of the total body water it's 40% of the total body weight total body water decreases with age what do you think about that well if you answered true you're correct total body water decreases with age okay the interstitial fluid and the intravascular fluid are considered compartments of the intracellular fluid true or false now if you said false you'd be correct the interstitial and intravascular fluid are considered components or compartments of the extra cellular fluid not intra cellular fluid individuals with more body fat have proportionally more total body weight so they are less likely to become dehydrated what do you think about that one if you said false you are correct that does not make them less likely to become dehydrated I will let's take a look at this idea of tonicity tonicity refers to the concentration of the fluid now if we're looking at this diagram let's take the middle one right there letter B and it says isotonic solution hopefully this is a review for you of chemistry but let's take a look at isotonic solution there in the middle what you see the circle in the middle of our picture is a cell and this cell has the same amount of particles inside the cell as there is in the solution outside the cell that means the fluid will move easily back and forth in and out of the cell all right look over to letter A we have a hypotonic solution in this situation now the number of particles inside the cell inside the circle is going to be more than the number of particles outside the cell which draws fluid into the cell fluid is drawn to where the particles are so fluid is drawn into the cell it makes the cell swell eventually that cell is going to swell so much to the bursts all right let's take the opposite equation now the opposite problem go over to letter C on the right hand side here our cell does not contain as many particles as our outside the cell so notice all those particles outside the cell right that's going to suck fluid out of the cell and into that hypertonic solution so that's going to dehydrate our cell isotonic solutions have the same solute concentration as blood think of normal saline as being your gold standard for an isotonic solution now normal saline is 0.9 percent sodium chloride in water so it's water plus almost 1 percent of sodium chloride a hypertonic solution is a solution that has a higher solute concentration than a red blood cell does a hypertonic solution is a solution that has a higher solute concentration than red blood cells in other words that means that this is a concentrated solution and that concentrated solution is going to suck fluid from outside the vasculature into the vein and make the vasculature expand so one of the reasons why we might give a hypertonic solution would be to expand the vasculature effects of a hypertonic solution on the cell are that we have the solute outside the cell is higher than inside water moves from low solute to high solute and the cell shrinks so our cell shrinks shrinks shrinks because of that hypertonic solution which means the sound wasn't going to work as well hypotonic solutions on the other hand these are solutions that have a lower solute concentration than the blood and if we inject it into the vein fluid is going to move out of the vein into the tissue the other thing that can happen when we inject a hypotonic solution is the hypotonic solution can move into those red blood cells make the red blood cells swell and possibly burst so the effects of a hypotonic solution are the solute outside the cells lower than the inside water moves from low to high the cell swells and eventually will burst that's going to swell and swell and then burst so what happens then when we infuse different types of solutions into the patient's veins an effusion of an isotonic solution in the vein is going to cause no fluid movement in or out of the vasculature so let's say that you're dehydrated well the pop physician is probably going to order for you some normal saline that's an isotonic solution there will be no movement of fluid in or out of the vein the fluid is designed to stay in the vasculature and increase the amount of vascular vascular fluid that's available an infusion of hypertonic solution in the vein is going to cause a movement of fluid from the tissues into the veins and in thirdly an infusion of a hypotonic solution in the veins causes fluid movement out of the veins and into the tissues this would be good if we want to try and rehydrate the tissues of the patient's body with this diagram here is illustrating error the differences between plasma interstitial fluid and intracellular skeletal muscle this is interesting it's not on the exam don't worry about memorizing this but I just want to show you give you some kind of representation as to how much of each thing happens to be in the plasma the interstitial fluid etc the one that I think is particularly interesting is the plasma so the plasma has most of the positive ion in the plasma is going to be sodium very little bit of potassium in there as well look over on the right side of it and you see that the vast majority of negative ion anion is going to be chloride a little bit of bicarb and a little bit of protein anions water excess occurs when the patient has too much fluid intake or they're not able to get rid of the fluid that they have on board so our compensatory mechanisms are no longer able to extreme all the excess fluid and the extracellular fluid volume increased so this could be caused by a clinical manifestation of a disease such as kidney disease or by an increased secretion of adh where we have an excess of water on board that particular syndrome is called SIADH the syndrome of inappropriate antidiuretic hormone and we are going to talk more about that with endocrine decreased blood flow to the kidneys and decreased cardiac output could also be signs of water excess excessive secretion of adh from fear of pain acute infections etc can cause the patient to also develop a water excess so what would we expect to see in our lab values as far as our hemoglobin or hematocrit and our serum plasma osmolality remember whenever you see the term osmolality always think of concentration so here we're talking about what would the serum plasma concentration be if the patient had water excess what would these values be increased or decreased well if you said decreased you'd be right okay think about it this way if we have water excess we have too much water on board that means we've diluted this stuff too much water excess will cause the patient to develop a DEMA this is an example of edema and the patient's ankle and foot in other words edema is swelling but we're talking about a specific kind of swelling this is the kind of swelling that is going to occur in a specific body area as a result of having too much float on board so it would probably be in both ankles it's going to be in an area that's dependent in other words that means it's lower than the rest of the body edema is an accumulation of fluid within the interstitial spaces it's usually going to be caused by an increase in hydrostatic pressure that means there's too much pressure in the blood vessel it could also be caused by an oncotic or osmotic pressure that's pulling fluid out of the vasculature into the tissues this is what your hypotonic solution does when we infuse it an increase in capillary permeability will allow fluid out and cause edema or lymph obstruction or leakage could cause the patient to develop edema there's a number of 30 things then that can cause the water movement to change or to happen between our different compartments the intracellular and extracellular flow so we have osmolality and again whenever you hear the term osmolality I always think of concentration so the concentration of the vasculature the plasma versus the concentration of the tissue itself on conic or osmotic force osmotic force again refers to concentrations concentrations of solutes in the fluid then we have net filtration filtration is the difference between our oncotic and our hydrostatic pressure hydrostatic pressure is the amount of blood pressure in the vessel fluid may move freely in the body between these different compartments but it will probably depend upon filtration osmosis hydrostatic pressure or osmotic pressure z' within the different compartments to move that fluid proteins and electrolytes contribute to our osmotic pressure so maintaining our fluids and our proteins and electrolytes will be very important if we want to try to maintain our patient's fluid volume status hydrostatic pressure is the push force osmotic pressure is the pull hydrostatic pressure is the push force of cardiac output and blood pressure osmotic pressure is the pull force of those electrolytes or those solutes in the tissue making a higher concentration couple components here a very busy slide I know there's a lot of stuff going on here but basically we have the arteriole end of the capillary in the venous end of the capillary at the arterial end of the capillary we are delivering our nutrients to those tissues on the venous end we're starting to pull those waste products out of the tissues and take them back and get rid of them any excess fluid or protein happens to be sitting around in the interstitial compartment will be returned to the lymphatic system and the lymphatic system then drains that fluid back into the central circulation now what this slide is illustrating is some of the movements that occur with fluid in the body we have our capillary fluid pressures so that's our hydrostatic pressure you see the hydrostatic capillary hydrostatic pressure is pushing the fluid out we can have filtration we can have oncotic pressure helping to reabsorb some of the things back into the vasculature we can have intracellular osmotic pressure that is also helping the move fluid in and out of the cell and then our lymphatic strains it away I like this next picture because it gives you an idea as to what's happening with the pressures in the capillary so we're way down at the capillary level there and if you look at the hydrostatic pressure it's saying the hydrostatic pressure is about 35 so we're talking about here literally is the blood pressure so when you take your blood pressure out there in your arm and you find out you have a blood pressure 120 over 80 that's what the blood pressure is up there in your arm but by the time we get all the way down to the tissue that's being perfused the hydrostatic pressure is going to only be about 35 millimeters of mercury now notice over there on the arteriole and our oncotic pressure is delivering about 25 millimetres of mercury force whereas the hydrostatic pressure is delivering 35 in other words the pressure in the vessel is 35 pressure outside is 25 therefore the net movement is more likely to move out rather than in when we move over to the right side of the diagram notice the oncotic pressure now is going to be 25 whereas the hydrostatic pressures down to 17 which makes the venous end more likely that it's going to be pushing our waste products back into that vasculature so then that movement there's more pressure on the outside than the inside therefore the waste products get pushed into that capillary hopefully to be excreted from the body so here are some of our normal lab values for some of our labs that we have to look at in relationship to our fluid electrolytes our serum sodium or serum osmolality the osmolality is the concentration of so that's going to be between about 280 and 300 serum sodium usually we say 135 to 145 okay again some reference values are a little bit higher or lower normal hemoglobin is 12 to 17 normal emetic rate is 36 to 54 and then our normal urine specific gravity is one point zero zero five to one point zero three zero one of the mechanisms that controls fluid balance is ADH that's antidiuretic hormone and one way to remember the fact of what it's doing is to think about that H on the end there it holds urine it's a hormone of the pituitary so that pituitary is stimulating the release of ADH also called vasopressin and it regulates the water balance so it tells the kidneys to hold on or reabsorb sodium and water of course if it holds sodium that means it's going to hold water and slows down or diuresis so the patient is not de reaching as much that means that the patient's going to hang on to fluid ADH is going to be stimulated by having a low sodium level in the blood stream so we're trying to hang on to sodium and keep the sodium level up it's going to be stimulated by a low blood volume low body fluid so in other words dehydration so whenever the patient starts to become a little dehydrated ADH is released and tells the body to hang on to fluid well we can have situations where we have ADH that's kind of out of control and that's called the syndrome of inappropriate ADH so there's too much or another way to think of that why this is the inappropriate release of ADH there's too much ADH being released into the bloodstream and that's going to cause the patient to hang on to too much fluid the primary cause for having SIADH is going to be neurologic so look for the neurologic problem in your patient if you're thinking this could be a SIADH that's occurring so one of the keys and a test question or in a patient that you're caring for would be to look for the underlying neurological disorder so we're going to look for the neuro disorder stroke for example or maybe brain trauma or a bleed or something like that that's occurring in the brain as far as some of these other etiologies cancers aids lung problems etc yes those can cause us a th much less common the more common reason why somebody's could have SAT H is going to be a neurologic dysfunction when you look at the manifestations these are all manifestations of having too much water onboard water retention edema formation all that kind of stuff is going to be the result of having too much water on board look at one of the manifestations here though dilutional hyponatremia okay let's take a look at what that word means hyponatremia means a low sodium level in the bloodstream and this is dilutional so we have the same amount of sodium we did before but the problem causing the low concentration of sodium in the blood is going to be that we have too much fluids or are diluting our sodium and now the concentration of sodium in the bloodstream becomes less that's a dilutional hyponatremia lab values for a patient who has SI 88 so let's take a look at these and talk about are they going to be increased or decreased so if the patient is hanging on to too much fluid what's going to happen to our serum osmolality remembers osmolality is concentration so if we're hanging on to too much fluid the concentration will go down it'll be diluted we'll have more fluid on board as opposed to our serum sodium will also go down because we're diluting it out hemoglobin hematocrit will fall because they're measures in relationship to the amount of volume we have and then lastly our urine specific gravity will increase now the urine specific gravity tells us the concentration of our urine remember that ADH antidiuretic hormone is keeping the patient from Diary Singh in other words it's decreasing the amount of urine output the patient has and therefore the urine is going to become more concentrated and a concentrated urine has a higher specific gravity let's take a look at and compare the syndrome of inappropriate antidiuretic hormone and diabetes insipidus these are two conditions of antidiuretic hormone ADH but there opposites of each other SIADH is from too much antidiuretic hormone whereas diabetes insipidus is from a lack of ADH okay now we're going to talk a little bit about diabetes insipidus a little bit later when we get into a our low volume states so fluid volume excess results in either losing or retention of fluid in the body so what do you think the correct answer here would be fluid volume access hanging onto too much fluid causes the retention of fluid in the body just as in fluid volume deficit the electrolytes are out of balance when there is a fluid volume excess as a consequence fluid moves from the extracellular compartment into the cell and cells will swell or shrink cells will swell if fluid is moving from the extracellular compartment into the cell as the secretion of adh increases the excretion of urine blank so what do you think as the secretion of adh increases the excretion of urine decreases again remember ADH is anti diuretic hormone that means if the patient has it they're not diary Singh if the patient lacks it they will be diary Singh so it's kind of like a double negative there if they lack anti then they will be diary Singh which of the following may indicate a fluid volume access warm moist skin cool dry skin mental confusion loss of weight convulsions and why so depending upon the etiology for having the fluid volume excess we may have warm moist skin we may have cool dry skin mental confusion is going to occur as a result of having a low sodium level we're not going to have a loss of weight with a fluid volume access in fact we will gain weight convulsions are possible because as the sodium level goes down we're going to have changes occurring in the patient's Mental Status into the opposite problem then would be a water deficit so the patient's dehydrated we don't have enough water on board and of course there's mechanisms in place in the body to try to prevent this obviously the most common mechanism that we use is going to be the kidneys kidneys himself we're going to kick in and I'm going to say hey let's hang on to fluid because this patient is becoming dehydrated so the manifestations we could expect to see with a water deficit or with dehydration would be tachycardia weak pulses and postural hypertension these are all signs of a low cardiac output state so as the volume decreases there's not as much volume to pump and our cardiac output goes down which then causes these compensatory mechanisms to be demonstrated our flushed dry skin might be possible we can also see dry mucous membranes our urine output goes down okay because the kidneys start trying to hang on to fluid the hematocrit and the serum sodium levels will then go up so there's three main types of dehydration we get an isotonic dehydration where we're losing just as much electrolyte as we are fluid and that's going to be a common type that we see with our extracellular compartment hypotonic type of dehydration where we have a greater deficit our electrolytes and then fluid that is being lost we might see this with somebody who has vomiting so we might end up with that kind of a situation where they're losing electrolytes from the vomiting hypertonic where we have a greater deficit of fluid rather than electrolytes or having more fluid loss than electrolytes being lost and that can cause some severe problems for our patient as well so it could be one of these three different types of our patients dehydrated we can't assume it's just going to be isotonic we have to check those electrolytes and find out where the patient's at so we know what to replace do we need to just replace the fluid do we need to replace the electrolytes as well when a patient has a water deficit in other words the patient's dehydrated what would we expect to see in these lab values so the serum plasma osmolarity okay so again osmolarity is concentration to our concentration in our serum will go up when we have a water deficit there's not as much water there's not as much fluid to dilute it serum sodium will go up because there's not as much fluid to dilute it or hemoglobin hematocrit will go up as well our urine specific gravity should also go up because the kidneys should be hanging onto fluid to try to retain our fluid volume now diabetes insipidus is the opposite problem of SIADH and SIADH we produced too much antidiuretic hormone now an S and diabetes insipidus on the other hand we are producing too little antidiuretic hormone two main causes this could be neurologic and that's where most of this comes from but could also be that the kidneys are not responsive to the ADH that is being produced so it could come from two different mechanisms usually it's going to be a neurologic mechanism so the patient cannot concentrate through urine and they're losing lots and lots of dilute urine which means the patient's going to become dehydrated the patient let's go down and take a look at these manifestations polydipsia is if the patient wants to keep drinking so they feel dehydrated they want to keep drinking they have polyuria which means that urine output is very high again not enough antidiuretic hormone if there's not enough antidiuretic hormone that means that the person is going to be diary seing tachycardia hypotension dry skin these are all things related to being dehydrated neurologic symptoms okay so lots of signs and symptoms of having diabetes insipidus again we just talked about some of these in relationship to have a volume deficit they'll be similar maybe in our patient who has diabetes insipidus let's see how they're different our serum osmolality the patient has is losing too much fluid so the serum osmolality will be high right the Sir Monson tration will be high because the patient's losing lots of fluid the serum sodium will be high because the patient's losing lots of fluid hemoglobin hematocrit will be high because the patient's losing lots of fluid but in diabetes insipidus the urine specific gravity will be low okay now that didn't make sense with a volume deficit a water deficit we said with a water deficit the urine specific gravity is supposed to be high as a result of the kidneys hanging onto fluid and trying to decrease the urine output so the patient can hang on to every drop of fluid that they have in the body but instead what happens in diabetes insipidus is we have a lack of anti diuretic hormone so the patient's diary sing and appropriately and they're having all of this dilute urine spilling out when it shouldn't be so here's our normal lab values again let's take a look at some case studies here talking about a patient with diabetes insipidus so here we have mr. aqua mr. aqua has polyuria with a urine volume of 8 liters a day that's a lot of urine volume think about that for yourself I mean that's a lot of urine volume there you're in specific gravity is one point zero zero two normally you're in specific gravity is anywhere from one point zero zero five to one point zero three zero big range okay because you're in specific gravity can change as you go throughout your day you didn't drink a whole lot of fluid this morning maybe your urines a little bit more concentrated than it is this afternoon but certainly one point zero zero two is less than the normal range serum sodium in this case mr. aqua has a serum sodium of 150 normal is 135 to 145 plasma osmolality is 305 normals up to 300 so those values are both high the sodium and the osmolality the concentrations are both high while his urine specific gravity is low those things don't fit together the normal presentation of your patient high serum sodium high plasma osmolality would indicate hydration and with dehydration we should have a high your in specific gravity the concentration of the urine should be high we should have concentrated urine instead we have dilute urine that doesn't fit with dehydration so when the urine doesn't fit with the serum sodium then we have to think about these alternate kind of problems such as diabetes insipidus and si ATH so what type of hormonal alteration might mr. aqua be exhibiting well in this case it's diabetes insipidus possible causes probably I would have to say we're looking for a neurologic cause for this condition the urine specific gravity we did talk about the pathophysiology already the specific gravity is low because the patient's producing lots of dilute urine your the serum sodium and serum osmolality are high because the patient is dumping lots of volume and concentrating their serum Ms Jane 85 has a small bowel obstruction caused by adhesions from a previous surgery over the past three hours or nasal gastric tube has drained 1200 milliliters of a brownish fecal smelling fluid this is common in a small bowel obstruction Ms Jane has been vomiting before coming to the hospital for the past three hours her urine output has told with 50 ml of concentrated urine okay now just so that you know because you probably haven't received this information yet a normal urine output should be 30 milliliters per hour so her urine output should be at least bare minimum of 90 for the past three hours 30 per hour but hers is only 50 her vital signs are repulses 100 or blood pressures 105 over 50 respirations 24-hour air temperatures 99 so a little bit in normal temperatures 98.5 here she is confused and restless she's getting an infusion of sodium chloride at 100 milliliters an hour these signs or symptoms indicate which high bulimia or hypervolemia bulimia so let's go back and take a look at some of her information again she's drained out twelve hundred milliliters of fluid from her nasal gastric tube this is a tube because in the to the nose goes down into the stomach and his draining fluid out of the stomach so she's lost twelve hundred milliliters okay so that's a leader over a little over a liter pretty significant amount of fluid from her stomach also for the past few days she's had vomiting before she came into the hospital so first of all she's not taking fluid in by way of the mouth she's losing fluid by way of her nasal gastric tube and vomiting now we see signs that our urine output is low indicating that she's probably not doesn't have enough fluid on board when you don't have enough fluid in your body your urine output goes down in order to try to maintain the volume that you do have her pulse is a little bit high at a hundred her blood pressure's a little bit low so these could all be signs that she has a fluid volume deficit or in other words hypovolemia which of the following patients are likely to need additional fluid so let's take a look at our list here confused patients well confused patients may need additional fluid because they may be dehydrated and that's what's causing their confusion certainly there would be we need to do a lot more workup we'd need to get a lot more information before we just give a confused patient fluid okay so that could be a cause but isn't necessarily the cause of the patient's confusion so we can't just give them fluid assuming that their confusion is caused by a lack of fluid very ill patients oftentimes will need fluid however some very ill patients like patients with heart failure giving them fluid is going to make them sicker so that is another situation where we're going to have to look at the patients in the situation and scenario to be able to decide whether or not they need fluid but certainly very ill patients typically need more fluid than other other patients will patients with an elevated temperature will need more fluid remember we lose fluid through the skin and in fact if that patient's temperature goes up they're going to start to lose more fluid both through the skin and through respiration remember the body as the temperature goes up the body's going to try and compensate and get the temperature back down again by increasing respiration and by losing more fluid through the skin causing vasodilation etc so we have an increase in our loss to the skin bacons with patients with a tracheostomy may need more fluid because the upper airway helps to humidify the air that's going into the lung and we just bypass that by putting in a tracheostomy burn patients need fluid infants okay remember again they have a large amount of body mass that's going to be fluid and if they lose even ten percent of that they could really be in trouble and the patients with cerebral injury may have fluid volume problems related to diabetes insipidus electrolytes are going to be elements that are dissolved in a solution and the body we're talking about elements that are going to be required for body functions some of the physiologic processes that electrolytes help to maintain are going to be the promotion of neuromuscular impulses a maintenance of our body fluid osmolality regulation of our acid-base balance and distribution of body fluids and electrolytes between the different compartments in the body the fluid of each of one of our compartments contains electrolytes and in many cases the amount of electrolyte in one compartment is not going to be the same as the amount in other compartments when one moves out of the cell another will have to come in to take its place for example the sodium potassium pump when potassium is pumped into the cell sodium is going to have to leave the cell otherwise we're going to have too much positive ion inside the cells so there's going to be some transaction occurring in order to move electrolytes around in the body the first electrolyte we're going to talk about is sodium and sodium is the primary extracellular fluid cation in other words the primary extracellular fluid positively charged ion it regulates our osmotic forces osmosis is concerned with moving fluid as Moses is concerned with moving fluids so as Moses is moving fluid in the body the function of sodium in the body is to move fluid to make sure that we have fluid where we need it in different areas of the body and to get rid of fluid if we have too much fluid on board sodium will be dumped through the kidneys fluid will follow it and the patient will get rid of that extra fluid if the patient is dehydrated the body will hang on to sodium and an attempt to also hang on to fluid so the roles of sodium in the body includes neuromuscular irritability or activity acid-base balance because it usually binds up with chloride show you their chemical reactions and membrane transport so now let's take a look at some problems that occur with sodium levels so first of all hypernatremia and hypernatremia we have a serum sodium that is greater than our upper level whether that be 145 147 is listed here but our upper level of our normal values related to sodium gain or water loss water movement from the intracellular fluid to the extracellular fluid which can happen with intracellular dehydration clinical signs and symptoms include intracellular dehydration so we're dehydrating ourselves that's not a good thing if this is a brain cell we're talking about Olsen's pulmonary edema hypotension tachycardia lots and lots of problems associated with hyponatremia now the problem with hypernatremia the problem that causes hypernatremia is a lack of fluid rarely is it the situation where the patient has too much sodium on board usually it's a situation where the patient has too little fluid on board so the treatment is going to be to give fluid to the patient what is showing here is the outside lining or the the outer blue circle around these cells is the size that the cell should be before it started to shrink as a result of our hyper and a Tremec environment so there's so much sodium in the external environment around the cell the cell starts to shrivel up because water from the cell is being given off into the tissues hyponatremia on the other hand is having a serum sodium less than 135 in this case we have too much water on board so a low sodium level is not a situation where the patient necessarily needs sodium but in fact instead is a situation where the patient has too much fluid on board this can happen in a number of different ways this can happen from the patient being in the hospital we're giving too much IV fluid this could also happen because the person is drinking too much water a very common situation used to be when people would run a long race they would have water stations and as the person is running they're losing both sodium and water in the sweat then they're replacing just the water at the water stations and people would end up having hyponatremia by the end of the race so now in most long races they have something like Gatorade that contains sodium so we're replacing both sodium and water during that race in this case here the inner kind of dotted line there is going to be the size of the cell should be now that the patient has hyponatremia there's too much water on outside of the cell the water is going to leak into the cell and make the cell swell now eventually the cell is going to become so big like a balloon it will pop and we'll have a cell death so that's not going to be a good thing again again we're just talking about random ordinary cells here but what if these cells happen to be cells of the brain you see that could be a really bad situation if we're having swelling of the brain tissue chloride is a very abundant anion in the extracellular fluid and I answer remember our negatively charged my electrolytes moves in and out of cells with sodium so chloride usually binds up with sodium we find those two things together the primary function of chloride is to maintain our acid-base balance in the body so aloe chloride level could be caused by the patient having a loss through the GI system or excessive sweating remember it's going to kind of move along there with sodium could be from a sodium or potassium deficiency that's causing the patient to develop a low chloride level a high chloride level could happen if we have a high sodium level remember those two things tend to go hand in hand but chlorides main function in the body is going to be to maintain our acid-base balance so these changes in chloride is not just a matter of hey it's just tagging along with sodium not doing anything it's tagging along with sodium and could be causing problems with our acid-base balance potassium on the other hand is the major intracellular cation the positive ion inside the cell and it's going to regulate our intracellular fluid volume so it's responsible for the fluid volume and the pH balance inside the cell potassium is very important for having a membrane potential and the ability of the cell to be able to conduct electricity so nerve conduction contraction of muscles especially those cardiac muscle cells and metabolic power processes so obviously we need to have enough potassium in the body very narrow range of our normal potassium 3.5 to 5 so we have a narrow range which is our normal range for potassium we don't want it going outside of that range because then we're going to have problems with nerve conduction contraction of kardea of muscles like our heart okay so that could cause some real serious problems whether patients being able to function we lose about 40 to 80 millions of potassium every day just via the kidneys just normal process falling out in the urine so we're going to have to replace that our patients are going to need 40 to 80 million watts of potassium coming into the diet every single day now we're not talking about somebody who's on diuretics we're not talking about somebody who has an excessive amount of fluid loss we're talking about your average everyday patient needs to get in 40 milli quit once per day a lot of times what we'll do is we'll add that 40 milli equivalents of potassium to the IV bag if the patients getting a regular IV some things that could interfere with or impact their potassium levels could be renal failure where the patient is no longer able to get rid of the potassium that we take it in the diet and then potassium levels could start to rise changes in pH will also affect our potassium balance now a low potassium level is considered to be a level that's less than 3.5 million once per liter and you can see some of the causes and some of the symptoms listed here lots of different causes of hypokalemia but we lose a lot of our electrolytes through the upper GI tract so the patient vomiting etc we can also lose thrown some through diarrhea potassium is one of those electrolytes that we're likely to be able to lose through the urinary tract so patients who are taking diuretics have a real affinity for losing their potassium lots of symptoms and when you're looking at your electrolytes look for symptoms to occur in three major areas of the body the central nervous system the peripheral nervous system and the heart so when we're looking at those three major areas the central nervous system we have anorexia and nausea fatigue and muscle weakness and then the peripheral nervous system we have paresthesias paresthesias are changes in sensation it's not a loss of sensation it's a change in sensation and then in the heart we're going to see cardiac dysrhythmias that can progress to cardiac arrest and in fact we can even see EKG changes the ukg change we see in hypokalemia is going to be a shallow flattened out T wave we may also see an additional wave on our EKG that's called a u wave you're going to get into more in analyzing EKGs later on in your program hyperkalemia on the other hand is a situation where we have too much potassium on board this is going to become causing increased neuromuscular irritability and the patient can have a lot of symptoms here that are going to be untoward so let's take a look at some of those so it causes renal failure is going to be the number one cause for having hyperkalemia if your patient has hyperkalemia the number one thing we're going to look for is renal dysfunction in that patient there could be some other things that are causing it but primarily the primary one is going to be renal failure now if we go and look for our symptoms into three main areas here we will be looking for the central nervous system nausea fatigue peripheral nervous system paresthesias muscle weakness to paralysis and in the heart cardiac dysrhythmias as far as our EKG goes with hyperkalemia we see tall peak to t-waves as opposed to having that flattened out T wave that we saw with hypo Caylee Mia calcium is a major not the major but a major extracellular cation so calcium is a positively charged ion that is in the extracellular fluid structure of the bones and teeth in fact 98% of the body's calcium is found in the bone so we have a huge amount of our calcium sitting out there in the bone it's needed for muscle contraction and relaxation this is the funny thing about calcium we need calcium to contract the heart muscle if we have too much calcium we're not going to contract your skeletal muscles so it has like an opposite effect on the heart versus the skeletal muscle calcium is also necessary for clotting and is involved in the clotting cascade in at least three or four different places so it's multiple places in a clotting cascade that calcium is necessary in order for a clot to form hormone secretion cell receptor functions and membrane stabilization are all necessary that we have calcium available calcium is controlled by the parathyroid hormone also vitamin D and calcium will regulate how much calcium is going to be absorbed in the body lastly we see here that we have an inverse relationship of calcium and phosphorus what this means is that if the phosphorus level is high then the calcium level will be low and vice versa if the phosphorus level is low the calcium level will be high they're inversely related so if we see that somebody has a low calcium level one of the first things we want to do is to go back and look at and see what their phosphorus level is and maybe that's the culprit causing the problem so here's a number of different causes of hypercalcemia the primary reason why somebody would have hypercalcemia would be that we have a loss of calcium from the bone so this could be a cancer a neoplasm this could be a situation of bone metabolism abnormalities Paget's disease is a disease of bone metabolism where too much calcium is being released from the bone symptoms we're going to see depressed neuromuscular activity in other words muscle weakness loss of muscle tone lethargy anorexia and nausea there's your central nervous system and in the heart cardiac dysrhythmias so we could expect to see those kind of things with a high calcium level low calcium levels you see a number of reasons why we would have that there now I previously mentioned that calcium is stored in the bone in fact 98% of our body's calcium is in a bone so in order to get calcium into the bloodstream we have to have some mechanism that allows it out and the gatekeeper is parathyroid hormone now once calcium is out in the bloodstream something needs to keep it there and what keeps the calcium in the blood stream is albumin the primary reason for having a low calcium will be a low albumin the primary reason for having low calcium will be a low albumin look at the patient's albumin level look at the patient's nutrition albumin is a protein and if the patient's not eating they're not going to have enough protein and they're not going to have a adequate albumin level therefore they won't have an adequate calcium level so opposite of what we saw with hypercalcemia hypocalcemia has increased neuromuscular stimulation muscle spasms cramps and dysrhythmias there's your your cardiac part of it Shostak sign intro so sign are specific signs that we use to tell us about neuromuscular irritability in patients who have some kind of electrolyte disorder you will learn more about these in your health assessment class but shostek sign is a tapping of the facial nerve that is going to cause the upper the eyebrow and the upper lip to twitch if the patient has neuromuscular irritability which are so sign is a little bit more barbaric what we do with that is we put a blood pressure cuff on a patient blow it up to 10 millimeters mercury above their systolic and leave it on for five minutes a positive torso sign is the hand and arm curl up as a result of neuromuscular irritability when the patient has that lack of blood flow to the arm they're probably going to smack you instead because that would be pretty uncomfortable having a blood pressure cuff on for five minutes well thank you for joining me for part 1 of fluid and electrolytes let's move on to part 2 now and talk about the rest of our electrolytes and look at some practice questions relating to fluids and electrolytes

Channel: David Woodruff

Views: 269,005

Rating: 4.8268795 out of 5

Keywords: Nursing education, nursing, nursing student, Pathophysiology, Fluids and electrolytes

Id: SDDaqoOKnrA

Length: 58min 26sec (3506 seconds)

Published: Fri May 17 2013