Med-Surg - Renal System, part 6: Acute Kidney Injury

Hi, I'm Cathy, with LevelUpRn. In this video, we are going to talk about acute kidney injury or AKI, and if you have our LevelUpRN medical surgical nursing flashcards, definitely pay close attention to the old red text on these cards because there's going to be a lot of important points that you definitely have to know. At the end of this video, I'm going to give you guys a little quiz to test your knowledge of some of the key points I'll be covering in this video. So definitely stay tuned for that. Acute kidney injury or AKI is the sudden loss of kidney function that is typically reversible. This is differentiated from chronic kidney disease, which is the gradual, irreversible loss of kidney function. So there are three general underlying causes of acute kidney injury. One is prerenal AKI. This means we have decreased blood flow to the kidneys, and this can be caused due to sepsis, shock, hypovolemia, as well as renal vascular obstruction. Then we have intra renal AKI. That's where we have damage directly to the kidneys. And this can be caused by physical trauma, hypoxic injury, or chemical injury due to toxins or medications. For example, Gentamicin is very hard on the kidneys and can cause intra renal AKI. Then we have post renal AKI. This is where we have mechanical obstruction to urine leaving the kidneys. This can be caused due to a stone, a tumor, or BPH, which is benign prosthetic hyperplasia. So this causes urine to back back up into the kidneys, which leads to impaired kidney function.
Let's now talk about the phases of acute kidney injury. There are four. The first is onset, so this is when kidney injury occurs from one of the reasons we just talked about. Then we go into oliguria where the patient's urine output drops dramatically. So they may only urinate less than 400 milliliters per day. And that excess fluid is going to back up in the body, which is going to cause edema and hypertension. Also, during this time, we are going to have electrolyte imbalances, such as hyperkalemia and hyponatremia. so that hyperkalemia can cause dysrhythmias and that hyponatremia can cause seizures. We're also going to have an increase in creatinine as well as BUN, and metabolic acidosis may be present as well. From oliguria, we're going to go into the diaresis phase. So now the patient's urine output is going to increase greatly, so they may urinate up to five liters per day. And we're going to start to see improvement in lab values such as creatine, BUN, and those electrolyte levels as well. Then from diaresis, we go to the recovery phase where we hopefully have the normalization of creatinine, BUN, as well as GFR. For a subset of patients, their BUN and creatinine levels may never fully recover and some patients may end up with chronic kidney disease, which will require lifelong treatment.
In terms of lab abnormalities that will be present with acute kidney injury. A couple of those I mentioned already, which include hyperkalemia and hyponatremia, we will also see hypercalcemia and hypermagnesemia. Metabolic acidosis will be present as well as anemia because the kidneys make erythropoietin, which stimulates red blood cell production, if the kidneys are damaged are not working correctly, they are not going to be producing that erythropoietin, which is going to cause a drop in red blood cells. And then, of course, we're going to have an increase in creatinine and BUN because of the kidney dysfunction that is occurring during AKI. In terms of treatment. We want to identify and treat any underlying cause, such as dehydration or a kidney stone. In terms of medications that can be used during AKI, we can use diuretics to help get rid of excess fluid. We're going to want to provide medications to bring down those potassium levels so we don't end up with dysrhythmias, so that can include calcium gluconate and then we can provide antihypertensive agents as well. The patient may require dialysis during AKI. In terms of nursing care, we want to implement seizure precautions because of the risk of seizures that comes with hyponatremia. We're going to monitor our patients' eyes and nose and their daily wait. And then we need to make sure they reduce or restrict their potassium intake, sodium intake, phosphate intake, as well as magnesium intake because of those electrolyte imbalances that we discussed.
All right, it's time for quiz. Three questions for you. First question; shock or sepsis can cause what type of acute kidney injury? The answer is prerenal AKI. Question number two; name the four acute kidney injury phases. The answer is onset, oliguria, diuresis, and recovery. All right, for the third question I want you to tell me whether the following labs will be increased or decreased. So first one; potassium? It will be increased. Second one; calcium? Calcium will be decreased. Creatinine? Creatinine will be increased. Sodium? Sodium will be decreased. Okay, that's it for this video. In my next video, we will talk about chronic kidney disease. So definitely stay tuned for that.