 Hi and welcome to nursing school explain this video on SIADH or syndrome of inappropriate anti-diarrheic hormone. If you've already watched some of my videos, you know that I'm a big fan of understanding the physiology behind the disease. So the pathophysiology because I feel that it really helps you gain a better understanding of why certain things happen in the body. And if you know how they're supposed to function and then there's something abnormal, it always helps you with understanding the symptoms and the treatment and the nursing care rather than just memorizing things. So in order to really understand SIADH, let's look and see where a IADH comes from. So it all has to do with the hypothalamus pituitary axis. And so remember the hypothalamus simulates the pituitary gland and then there's two sections, the anterior and posterior pituitary gland. And from the posterior pituitary gland in response to low blood pressure or increased serum or similarity, anti-diarrheic hormone gets secreted, which then acts on the kidney to reabsorb more sodium and reabsorb more water to bring the blood pressure up. Remember the more volume we have in our system, the higher the blood pressure will be. And then there's a negative feedback loop. So now if the blood pressure is back to normal, the simulation goes away and everything is back in balance. Now when there's too much ADH being secreted, then we're dealing with syndrome of inappropriate ADH. When there's not enough ADH, then we're dealing with a different disorder called diabetes insipidus, also called water diabetes. And please see my other video about this, this order. So in terms of SIADH, causes of SIADH can be pituitary dysfunction. Remember that the pituitary secretes ADH. So if there's something going on with that master gland, then we might have SIADH. And so pituitary dysfunction can be anything related to a stroke, trauma, infection, encephalitis, meningitis, and other things such as mental illness as well as psychosis. Other causes are malignancies in the body such as small cell lung cancer, which definitely is one of the major causes. And in certain medications and drugs can cause SIADH. And some of those offenders are seizure medications as well as SSRIs which are selective serotonin reuptake inhibitors that are used in the treatment of depression and anxiety. So when we now have too much ADH, so too much water retention, the urine output is going to go down because all the water and sodium are being reabsorbed, right? So less output. Then the patient when we have too much fluid will have weight gain, but mostly that will be without edema. They will be thirsty because they're not excreting as much volume. There might be dyspnea on exertion, so shortness of breath with activity, as well as signs and symptoms of hyponatremia. So when the sodium goes low, signs and symptoms initially may be headache and irritability, but as the sodium drops lower anywhere below 120, which is a really significant hyponatremia, the patient might have additional symptoms and they can be vomiting with abdominal cramps, muscle twitching, and then more severe, cerebral edema, ulter level of consciousness, lethargy, seizures, and even leading to coma. So keep in mind that whenever sodium goes out of balance, we always have to think about mental status. So how is SIADH diagnosed? Basically we will have dilutionary hyponatremia, which basically means that too much volume, too much fluid is being reabsorbed, which dilutes out the sodium. So now we have so much, if you think about chemistry in a beaker, right? We have so much fluid and only a few particles, so these sodium particles are going to be diluted in all this volume that we're now reabsorbing with this inappropriately functioning ADH. And that can be evident by sodium levels less than 134, so just below the normal range or lower, and then serum osmolarity less than 280, so very dilute osmolarity of serum concentration. And then with that, we're going to excreteless sharing we set up here, so the urine specific gravity is going to be high, greater than 1.025, which means that the urine is being more concentrated. So we're reabsorbing more water so that in the system, the sodium and the other electrolytes might be diluted, whereas in the urine, we're only excreting a small amount of urine, and so the particles will be more concentrated, hence the elevated urine specific gravity. The treatment for SIEDH, we always want to address the underlying cause. So if this is pituitary dysfunction for any of these reasons, we want to address them. If the reason is small cell lung cancer or any kind of malignancy, that's certainly no need to be addressed, as well as if the offenders or any of these medications will want to discontinue them. And then because all of these symptoms occur because of fluid volume excess and too much fluid in the system, the patient will need to go on a fluid restriction and that might be as low as 800 or 1,000 millionaires per day. And because they're going to be very thirsty, we want to provide frequent oral care and give them ice chips to kind of have a diminished at-thirst mechanism. And because we have all this weight gain and excess fluid, the patient probably will need loop diuretics such as Lasix and always remember to take a potassium level before you administer Lasix for a patient. If the sodium level goes below 120 and the patient has neurological symptoms that we discussed up here, they might need to receive hypertonic saline which is also 3% sodium chloride. And remember that hypertonic saline is only really used in two different instances which number one is severe hyponatremia with neurological symptoms or brain injuries such as from a from brain trauma where the cerebral cells get really swollen by administering the hypertonic saline. We're able to pull some of that fluid off the brain cells and hopefully relieve some of those neurological symptoms. And then there's also medications called vasopressin antagonists and 12-10 is an example of that. As for nursing care because we're dealing with fluid volume status as well as sodium, we always monitor the patient's sodium and neurological status for all these reasons we discussed over here. Definitely we want to keep an eye on their daily weights and eyes and nose as well as monitor the bioscience frequently and then check that it's harder than lung sounds to check for fluid volume excess because we know when there's too much fluid in the body it will tend to settle in the lungs and then be evident as crackles and then we have a whole lot of other problems to deal with and most likely the treatment will be Lasix and more fluid restriction. And then because of the significance of the neurological symptoms, we want to have seizure and fall precautions for these patients with SIDH. So thank you for watching this video. I highly encourage you to also watch the video on diabetes and syphilis which is the opposite. So too little of ADHD that's caused by also pituitary dysfunction and other things. And so please like this video, give me a thumbs up, subscribe to my channel, share it with your nursing friends and I'll see you again soon here on Nursing School Explained. Thanks for watching.