hey everyone it's Sarah register nurse rn.com and in this video I'm going to be doing an inlex review over acute kidney injury also known as acute renal failure and this video is part of an inlex review series over the renal system and don't forget to check out at the end of this YouTube video the quiz that will test you on acute kidney injury so let's get started so what is this condition it is where there is a sudden decrease in renal function so it comes on quickly and the kidneys aren't able to filter the blood like it should and because of this you get buildup of waste in the blood like bu and creatinin which are waste products from muscle breakdown and protein breakdown you also we'll see fluid build up in the patient because again those kidneys cannot remove that excessive fluid from the blood and electrolyte in balances now acute kidney injury can be reversible if it's caught early and the cause is treated appropriately so what exactly can cause acute kidney injury well we have three different causes based on the location where it's located in the body the first type of cause that we're going to talk about are the pre-renal causes and for inlex and your nursing lecture exams be familiar with the causes that can cause this and where it tends to be located before the kidney inside the kidney or after after the kidney because that's where a lot of test questions like to come so prerenal prerenal just like the name says it's before the kidney so any problem that's really arising from the renal AR artery upward upward to the heart so your heart and your kidneys work hand inand together what your heart does is it takes the blood and it oxygenates it through the lungs and it goes back to the heart and then it pumps it out through the body and that fresh blood will go down through the heart through the descending aorta and then go into the kidneys through the renal artery and Branch off into all these arterials and go and feed to the nephrons of the kidneys and remember each kidney has millions of nephrons and those nephrons are responsible for filtering the blood and reabsorbing nutrients and then creating urine filtrate which is voided out through the bladder through the urethra so it all works together like this beautiful process however if you get a profusion issue this can decrease the function of the kidneys so you have decreased profusion which is going to decrease the function of the kidney now what happens is that there's a decreased amount of blood going to the kidney to be filtered and the kidney is being deprived of nutrients so it's not able to work like it should and eventually this can actually lead to intrarenal injury where those nephrons inside the kidney become damaged and they quit filtering like they should so what exactly can lead to a prerenal injury causing that decrease profusion okay a f one thing is a cardiac issue and what can happen is if there's damage to the heart muscle it's not able to contract properly these ventricles become weak they cannot pump that blood down through that descending aorta so you get decrease cardiac output which is going to decrease the profusion to the kidney what kind of conditions can cause this well one thing is a mardial infarction the patient has a heart attack and some of that part of that ventricle has died maybe a large part of it because of aeia to the muscle it was irreversible and so that heart muscle is just weak and it cannot pump get decreased cardiac output another thing is bleeding if you get Massive Internal or external bleeding there will be decreased blood volume going to that kidney not profusing it dehydration with excessive diarrhea vomiting the patient becomes hypovolemic and another thing are Burns which again is depleting the system of fluids then there are interrenal causes and this is where there is damage to the nephrons so the problem is within the kidney itself so if you took the kidney and you sliced it in half you could find where the mil where these millions of nephrons are located and if you drew out a nephron and stretched it out it would look something similar like this you would have the following structures and the nephron can really be divided into two areas based on what they do you have the renal Cor pusle which is your filtering structure and that includes your glomus and Bowman's capsule then you have the renal tual which includes your proximal convoluted tubal Loop of Henley distal convoluted tubal then your collecting tubal and collecting ducts and this is really where uh the body where the renal system is going to remove excessive water or put more water back into the bloodstream and really tweak those electrolytes based on what you need so it's really maintaining homeostasis in the body then whatever you don't need you're going to void it out and each nefron sets within the kidney but the top part of the nefron sets in the renal cortex and the bottom part of the nefron specifically the loop of Henley and part of the collecting tubule SL duct sets in the renal medulla and that's why whenever you look at the kidney structure you see those striations on the renal pyramid it's because of the bottom part of the Nephron giv giv it that appearance so if you have a problem with your nefron what's going to happen you're going to have a decreased ability to filter the blood which is going to lead to excessive waste building up into the system it can't remove it you're going to have excessive water building up and it's not going to be able to maintain electrolyte levels where they need to be so what can cause intrarenal injury well one thing is never talk drugs drugs that are really hard on the kidneys and this includes drugs like ineds antibiotics specifically the aminoglycoside family chemotherapy drugs or contrast dye like the dyes that patients receive for certain testing another thing is infection and we talked about this in our glomo nephritis video which is one of the causes if it's not treated appropriately and they have a really severe case they can enter into this condition and injury to the kidney and lastly there are postrenal causes and this is where you can have blockage in the urinary system after the kidneys that can even extend all the way to the urethra and what this will cause is it will prevent the urine from draining out of the system so you'll get build up of pressure in the kidneys from where all that urine is just staying in there and back flowing to the kidneys and you have all this waste that isn't leaving the kidneys so this can decrease the kidney function so for instance say that you have a renal calculi that can be a cause it's obstructing urine flow and remember it can be anywhere from the uror to the bladder to the urethra so another cause could be an enlarged prostate prostate in men it can squeeze that urethra close so they have problem emptying the bladder and it can cause backf flow of urine and then things that cause a brain injury a neuro damage where like a stroke where the bladder does not empty like it should so they get the retention of w of urine it it can back flow and cause acute kidney injury so before we look at the stages of acute kidney injury let's cover the basics about the kidney and look at the labs that are ordered by The Physician to determine if this is renal failure because whenever we're going through the stages our nursing interventions and the signs and symptoms it's going to make sense why you are seeing an increased bu in creatinin or a decrease GFR and it'll help you understand that material a little bit better okay so Basics about the kidney okay it's important to know how much a an adult should be voiding normally they should be voiding one to two liters per day because depending on the stage like if they're in the aloric stage of acute kidney injury they will be voiding usually less than 400 MERS of urine so you'll want to be watching out for that because they should be voiding at least one to two now they're voiding more than two like three to four maybe five or six liters of fluid they could be in the diuresis stage now what does urine consist of substances really our body doesn't need so you're going to be finding water in there ions that will rain from sodium to Chloride to calcium phosphate bicarb everything like that because remember our nefron pick and chose what we needed to maintain that homeostasis in our body along with waste products because we do not want that to build up in our body like Ura Ura is measured in The Bu level the blood Ura nitrogen level and this is a waste product from protein breakdown in the liver and then we have creatin which is a waste product from muscle breakdown and we want to maintain a fine balance of this and a normal creatin level is 0.6 to 1.20 millgram per deciliter so let's talk a little bit about creatinin because now we're getting into our Labs so creatinin is measured a lot whenever renal failure is suspected because they will take your creatin level your creatin clearance and your glomular filtration rate along with the bu to really determine how well those kidneys are filtering and removing waste from the body so creatinin creatinin is solely filtered from the blood via that glomerulus so blood's going through the Glarus creatinin is dripping down in there now normally other substances that go through there like water and sodium potassium will go through the renal tubal and it's going to parts of that of the sodium and water are going to be reabsorbed back into the system and what we don't need will void it out well with creatinin it's not going to be reabsorbed or secreted in the nefron it is solely just filtered out which is why creatinin is a great measurement to help us determine the ability of how the kidney is filtering so we can measure how much creatinin is in the blood and if we have too much creatinin in the blood we know that we have decreased functioning of our kidney which is why we can also look at what is called the creatinin clearance level and this is the amount of blood the kidneys make per minute that should be free of creatinin and it the varies differ based on gender so for females the normal range is 85 to 125 Mill per minute that is the amount of blood that that woman should be producing through the kidneys that should not contain creatinin and for males it'll be 95 to 140 milliliters per minute now you can use the creatin and clearance values along with the patient age gender weight race to determine what is known as the glomular filtration rate the GFR and what is the GFR the GF R is the rate of blood flow through the kidneys so it tells us how well the glomus is filtering the blood because that's that main structure in that nefron that is doing that job so a normal GFR should be 90 milliliters per minute or higher and again it takes all these other things like the age of the gender the weight and the race into consideration when calculating this estimation so let's take a little quiz if our GFR is decreased our glomus is not filtering that proper amount of blood what's going to happen in our body what are we going to see in our patient okay what is their urinary output going to do when you have a decreased GFR is are they going to be putting out a lot of urine or is it going to decrease their urinary output is going to decrease they're going to become they may experience aoria less than 400 milliliters per day of urine and that urine is going to become concentrated because that glomus is not filtering the amount of blood it should it's decrease what is going to happen to the water in the body it is going to increase because the glomus is not removing the right amount of water so it's going to stay in the blood what's going to happen when we have too much blood water in the blood we're going to get some hypertension edema swelling now what will happen to the waste in the blood specifically The Bu and creatinin levels they're going to really increase as well so your patients going to start experiencing azotemia which is the buildup of waste in the blood and they can enter into metabolic acidosis acidotic conditions because they are not excreting those hydrogen ions like they should and you have decreased bicarbs so we're going to get that and then another thing what do you think is going to happen to your electrolyte they're going to be all over the board specifically you're going to see high potassium levels like hyperemia phosphate levels can be high and their calcium levels can be low among those other types of electrolytes so anytime if you get to have clinicals on a renal floor or you're working on a renal floor always look at those labs before the patient is scheduled for dialysis because dialysis is one of those treatments for this condition and you will notice that before they go for out dialysis the patient blood pressure is going to be super high they're going to have swelling you're going to go look at their Labs they'll have an increased bu and creatinin their potassium level will be Sky High and uh they will have in their folley if they have a folley usually they do their urine will be really really dark and they'll just be like a very small amount in the Foley bag and then after they go to dialysis their blood pressure usually is better and whenever you draw Labs morning Labs those levels will be down because it's removed it's replaced the job of what your nefron should have done in the first place that dialysis machine okay so now let's look at bu what was bu that was measuring that Ura level it's blood Ura nitrogen level a normal level for this should be six 6 to 20 milligrams per deer and again Ura is the breakdown of protein in the liver so liver breaks down the protein secretes it into the blood because it knows whenever it does this that the kidneys are going to take it and filter it out however if the kidneys aren't working properly it's not going to be able to remove that Ura so you'll have high levels of BU greater than 20 in this condition and also something that can increase be levels are conditions like that cause dehydration now let's go over the stages of acute kidney injury and as I do that make sure you pay attention to the name of each stage how they occur and the signs and symptoms that present in each stage along with the nursing intervention that goes along with that sign and symptom because that is where test questions like to come from whenever you were studying this condition okay so the first stage is called the initiation stage and just as the name tells you this is when it starts so it starts Whenever there is something causing that kidney to become injured either pre-renal postrenal or intrarenal cause and it ends when the signs and symptoms start to appear which can occur a few hours to several days and this is really when you want to find out the cause and treat that cause to prevent long-term damage to those nephrons because if it's not corrected soon enough they can enter into chronic renal failure which is what we will be talking about in the next video okay now after after the initiation phase patients can go into What's called the aeric phase now it's important to note that some patients will actually skip this stage and enter into the next stage the diuresis stage so you may have a patient who has renal failure the beginning stages of it but they have massive amount of urinary output and they're not putting out Le a low amount of urine that you would expect so they may have skipped this stage and went to the next stage okay so the augc is where you will notice that your patient's urinary output is going to be less than 400 m per day and why why is the urinary output so decreased well remember it's because the garus has decreased in its function to filter the blood so when you look at the labs they're going to have a decrease GFR okay so let's look at the signs and the symptoms because they have a decreased GFR they're going to have a an increased bu and creatinin that waist level azotemia so your patient is probably going to have some neurostatus changes they're going to be confused really sluggish and tired and sleeping all the time and they can also itch from where that waste has built up and it causes itching on the skin nursing interventions for that you want to watch their protein consumption so limit that because remember the breakdown of protein in the liver increases Ura levels so you want to limit that and their safety because they're going to be confused may not know where they're at they can get up and fall things like that another thing is hyperemia and this is because there's an decrease excretion of pottassium in those kidneys and what can happen whenever you have a high potassium level you have to watch out for cardiac issues they can have a significant cardiac event so you got to watch the EKG and look for tall and peaked tea waves wide QRS complexes and prolong PR intervals that can represent hyperemia so your nursing interventions would include restricting potassium rich foods we don't want to give them any more potassium they have enough monitor their EKG they need to be on a bedside monitor to watch that assessing Labs The Physician May order a medication called K exelate either orally or rect and this will help bring down that potassium level so be familiar with that another thing is they will have increased fluid in the body because the glomerulus is not removing that excessive water so you can see swelling throughout in their face around the eyes and their legs so edema uh they because of that they are at risk for pulmonary issues from where all that extra flu is going to go into the lungs cause breathing issues they can have cardiac issues from that hypertension from The increased blood volume so nursing interventions would include limiting their fluid intake uh monitoring their intake and output very strictly we want to know exactly what they're taking in and exactly what they're putting out daily weights get them up every morning use the same scale and weigh them because weighing a patient is a great indicator of how much water they are retaining and then as a nurse you want to look at the weights okay today's weight they were 200 yesterday they were one one 90 so they've gained 10 pounds that's very significant monitor their blood pressure because they're going to have hypertension assessing those lung sounds for crackles which would represent pulmonary edema monitoring their oxygen saturation looking at that swelling going on is it decreasing or is it getting worse okay next they can go through what's called metabolic acidosis and this is because you have decreased excretion of those hydrogen ions so you're getting very acidic blood and their P blood pH could be less than 7.35 and they may present with confusion with that along because they have an increased V and creatin level too and they may be doing a type of breathing called cosmal breathing and this is a deep rapid breathing and it's your body's way of trying to compensate to increase that blood pH because it's very acidic so carbon dioxide is an acid so your body is causing them to breathe deeply and rapidly to blow off that carbon dioxide out of the system hoping to increase the blood pH so you may see that so what you want to do nursing intervention wise is monitor their safety because of confusion and their respiratory status as well and patients can also present with mild hyponatremia so a low salt level it'll be very mild or it could be normal it could be the reason for this is because the blood is diluted from the extra fluid that's in the blood so that level can run low also they'll have they may have an increased phosphate level and a decreased calcium level because remember phosphate and calcium are opposites if one's High the other ones L ones or vice versa so you want to restrict their phosphate foods and monitor that and another thing they can have is that really concentrated urine so if they produce any urine really at all it'll be really dark and concentrated and it'll have a high urine specific gravity and that will be any value greater than 1.020 now how long does this stage tend to last tends to last a week to two weeks and you want this stage to be as short as possible because the longer the stage is the longer and more of an increased chance there's going to be damage to those nephrons and again they can enter into end stage renal disease chronic renal failure and the treatment for this stage is dialysis our next stage is called the diuresis stage and this is where our nephrons are on their way to recovery but they're not 100% yet but they're getting there so now they have the ability to actually filter the blood so they can start bringing down our waist levels that bu and creatinin getting that out however they can't concentrate the urine yet so we're not really going to get some electrolyte balance and our water levels are still going to be crazy now the GFR is improving but it's still abnormal so that's why you're seeing the decrease in The Bu and creatinin but it will those levels will still be abnormal but your patient will start to become more aler and oriented compared to how they were in the previous stage the aloric now your patient is going to be voiding a massive amount of urine about 3 to 6 lers per day and why is this this is due to what's called osmotic diuresis okay so remember the kidneys can filter the blood now now it has a lot of waste to filter out so what's going to be in that filtrate a lot of Ura so that newly created filate is jamack full of Ura this is going to cause osmotic diarrhea it's going to pull a lot of water out they're going to be voiding 3 to six lers per day now because of that think use nursing knowledge because we have V we're avoiding so much fluid out what's going to happen to our fluid status in our body in the previous stage we are fluid overloaded now we're fluid depleted so we're going to become hypovolemic we're at risk for dehydration hypotension what's going to happen to our electrolytes well before we are struggling with hyperemia now we're voiding so much out we're going to be wasting potassium so we're going to have hypokalemia and how's our urine going to be it's going to be really diluted so they'll have less than 1.020 urine specific gravity the urine's going to be really diluted so nursing intervention wise what we want to do is we want to maintain strict eyes and oath because they're going to be losing a lot of fluid those daily weights signs and symptoms of dehydration and the physician May ordering supplements to replace those electrolytes that are low because they're being voided out and they may be on IV fluids which seems like a paradox for someone who's a renal failure but if they're in this stage they need it so they don't go into dehydration now this stage can last anywhere from a week to three weeks okay so after they go through this stage they hit the last stage called recovery and this start s when the GFR returns to normal now let's ask ourselves what is going to happen with our urinary output since our GFR has returned to normal we're going to be normal so one to two lers is what they should be putting out per day what's going to happen to our bu and creatinin it's going to become normal it's going to stabilize and our electrolytes are going to be normal where where they need to be so every everything will be maintained and that's how we know that we are in the recovery stage now this stage can take a year more depending on the amount of damage that was done how long they spent in the aorc stage and the patient age so it's different for every patient now some patients unfortunately never make it to the recovery stage because there's just too much damage and instead they develop what's called chronic kidney disease infe adrenal failure which we will be talking about in the next lecture so this wraps up this lecture on acute kidney injury thank you so much for watching don't forget to take the free quiz and to subscribe to our channel for more videos