Electrolytes Made Easy: Hyponatremia & Hypernatremia Explained for Nursing Students

  Electrolytes Made Easy: Hyponatremia & Hypernatremia Explained for Nursing Students

Part 1 in Series

Hey everyone, welcome back to Nursing School Week by Week. I'm your host, Melanie, and today we are tackling a huge topic in nursing school, one that confuses so many students but is absolutely critical to understand, electrolytes. Now before you tune out and think, uh, I'll just memorize some lab values and move on, let me stop you right there.

Electrolyte imbalances are not just something you'll see on an exam. They're real, they're dangerous, And they can be life threatening. Alright, imagine this. You're a brand new nurse on your first job. It's a busy shift. You're already behind on charting. You've got 3 call lights going off at the same time.

And then your preceptor tells you, Hey, your patient in room 312 is acting confused. Why don't you go check on them?  Okay, confused patient. What's going through your mind? Could it be low oxygen? Should you check their O2 saturation? Could it be low blood sugar, maybe they need some juice, or is this an electrolyte imbalance?

The thing about electrolytes is that their symptoms can mimic other conditions. But if you miss them, your patient could be in serious danger. That's why in today's episode, we're going to break them down in a way that actually makes sense. By the end of this series, you'll be able to spot an electrolyte imbalance from a mile away and know exactly what to do.

Alright, we're going to focus on the four big players, the all star electrolytes. And those are sodium, or the brain's best friend. Potassium, the heart's MVP, calcium, the muscle stabilizer, and magnesium, the calming mineral. We'll talk about their normal ranges, what happens when they go out of whack, and most importantly, the nursing interventions that could save your patient's life.

And since I know you've got exams and the NCLEX coming up, I'll be throwing in some review questions along the way to help lock in this info. Alright, let's jump right in with sodium, often nicknamed the brain's best friend. But why? What makes sodium so important?  Well, sodium is like the manager of fluids in your body.

It keeps everything balanced, making sure fluids stay where it's supposed to be. It also helps with nerve function and muscle contraction, which means your brain, nerves, and muscles all depend on sodium to work properly. And the normal range for sodium is 135 to 145 milliequivalents per liter. Now what happens when that number drops below 135?

We call that hyponatremia, which means low sodium in the blood. And since sodium is the brain's best friend, guess which organ is the first to freak out when sodium levels get too low?  That's right, the brain.

So some symptoms of hyponatremia, if you're patient. has low sodium, their brain is not happy. So you might see confusion. The patient might not know where they are or seem disoriented. Lethargy. They could be extra tired, groggy, or hard to wake up. Muscle cramps or weakness. Uh, seizures, if sodium drops really low, the brain can't function properly, leading to seizures.

And in severe cases, the brain can shut down completely, and your patient will go into a coma. So basically, the brain is screaming for help, because it doesn't have enough sodium to function properly.  Now what causes hyponatremia? There are a few major culprits, and they all have one thing in common. They mess with the balance of sodium and water in the body.

So, the first one is SIADH, or Syndrome of Inappropriate Antidiuretic Hormone. This is when the body holds onto too much water, diluting sodium levels. Imagine adding a ton of extra water to a salty soup. It would make it less salty, right? That's exactly what happens in SIADH.

Another cause is heart failure and kidney disease. These conditions can cause fluid overload, which again dilutes sodium. Another cause is diuretics like hypochlorothiazide or furosemide. These medications make the body get rid of water, but sometimes sodium gets flushed out too. And if your patient has any kind of excessive vomiting or diarrhea, losing a lot of fluids means losing sodium too.

So they could become hyponatremic. And then just drinking too much water. You can actually drink too much water and it can dilute your sodium to dangerous levels. Many of you know that I am a U. S. veteran for the Air Force. And when I was in basic training, The drill sergeants would constantly be telling us to drink water, drink water, hydrate.

Because the main risk was getting dehydrated just from all the running and push ups and sit ups and it was just go, go, go. But one of the girls in my flight took that a little too seriously and drank a ton of water. And she had to go to the clinic because she was most likely hyponatremic.

She had drunk so much water that She diluted the sodium in her blood to dangerous levels.

All right, let's look at a real world scenario.  You walk into your patient's room. They're confused, a little groggy, and not making much sense when you ask them questions.  Are they just tired? Maybe. Are they over medicated? Could be. Or, could it be low sodium? You check their labs, and sure enough, their sodium is 128.

Remember, the normal range is 135 to 145. At this point, you know their brain isn't getting what it needs. And if you don't fix it, things could get much worse. So what do you do? Your first job as a nurse is always to keep the patient safe, right? So first you're gonna check their airway. If they're confused or having seizures, make sure their airway is protected.

Then you're gonna restrict fluids. If their sodium is low due to fluid overload, they don't need more water, making the problem worse.  Next, you're going to monitor their neuro status. Any change in their level of consciousness is a huge red flag. And then administer hypertonic saline if ordered. Now this is for severe cases and it has to be given slowly under careful monitoring because if it's given too fast, that can cause dangerous brain swelling.

Alright, so the key takeaway is if a patient's sodium is too low, their brain will be the first to show signs of trouble like confusion, lethargy, muscle weakness, seizures, any of that, think hyponatremia.  Now, we've covered what happens when sodium is too low. Next, we'll cover what happens When it's too high, and that's called hypernatremia, and that comes with a whole different set of problems.

But first, let's do a quick pod quiz to test your sodium knowledge. I'll read the questions and the answer choices, then give you a few seconds to think before revealing the correct answer. Ready? Let's do this. Question number one. What's a key neurological symptom that screams hyponatremia?  A. High blood pressure, B.

Confusion, C. Increased urine output, or D. Leg swelling. Take a second to think.

  And the correct answer is B, confusion. And that's because since sodium is the brain's best friend, low sodium or hyponatremia hits the brain first. The most common neurological symptoms are confusion, lethargy, and in severe cases seizures or coma. So if you walk into a patient's room and they're suddenly acting disoriented or sluggish, check that sodium level ASAP.

 Question number two. What's a common cause of hyponatremia?

 A. Dehydration B. SIADH or Syndrome of Inappropriate Anti Diuretic Hormone C. Eating too much salt or D. Hyperventilation Think about it.

 And the correct answer is B. SIADH.  And that's because SIADH causes the body to hold on to too much water, which dilutes sodium levels in the blood. Imagine adding extra water to a salty soup. It would make it less salty, right? And that's exactly what happens in hyponatremia. Other causes include diuretics, heart failure, kidney disease.

and excessive vomiting or diarrhea.  Alright, question three. If you're assessing a patient who's confused and has a sodium level of 128, what's your priority nursing action?  Is it A, start a normal saline IV as fast as possible, B, restrict fluids, C, give the patient extra salt packets with their meal, or D, place the patient in Trendelenburg position.

Think carefully.

 The correct answer is B, restrict fluids. That's because if hyponatremia is caused by fluid overload, then giving more fluids will only make it worse. Instead, the first line intervention is fluid restriction to help concentrate the sodium levels back to normal. You'll also need to monitor neurostatus closely.

If symptoms worsen, the provider may order a hypertonic saline. But only in severe cases and given very slowly to prevent brain swelling. Alright, so how did you do? Let's recap. Confusion is a major red flag for hyponatremia. SIADH is a common cause because it dilutes sodium in the blood. And restricting fluids is the priority intervention for fluid overloaded hyponatremia.

If you got all three, give yourself a high five. If not, no worries. Just rewind and reveal.  Alright, up next we're tackling hypernatremia, AKA. What happens when sodium gets too high?

Now, hypernatremia is a little trickier than a hyponatremia because the symptoms can be more subtle, at least at first, but here's an easy way to remember it. Think dry. D R Y. Hypernatremia equals too much sodium, not enough water. The body is dehydrated and crying out for fluids. It's dry.

Some symptoms of hypernatremia. When sodium levels are above 145, the body goes into full on SOS mode, trying to fix the imbalance. And here's what you're going to see in your patient. You're going to see extreme thirst. They cannot get enough water, no matter how much they drink. Um, you're going to see dry mucous membranes, so they're Mouth, tongue, and lips might be cracked and dry and then restlessness or agitation.

The brain doesn't like this imbalance and your patient might seem irritable or just off. Um, you might see tachycardia, fast heart rate, and hypotension or low blood pressure. If dehydration gets really bad, the heart starts pumping harder to compensate for that lack of fluid in the body. And in severe cases, once again, you might see seizures and coma.

  If hypernatremia isn't corrected, it can lead to brain dysfunction and even death. So if you see a restless, dehydrated patient, check that sodium level.  Now, what causes hypernatremia? There are two major causes. One, not enough water or dehydration, and this is the most common cause. If your patient isn't drinking enough fluids, or they've lost a ton of fluid through vomiting, diarrhea, even sweating or fever, sodium levels start climbing higher and higher in the blood.

This is especially dangerous in older adults who may have a decreased thirst response and not even realize they're getting dehydrated. And then the second major cause of hypernatremia is too much water loss, so, um, such as in diabetes insipidus. This is a medical condition where the body dumps water uncontrollably, Leading to severe dehydration and high sodium levels.

Patients with diabetes insipidus can pee out huge amounts of diluted urine. We're talking liters and liters a day. Even if they drink a ton of water, they still can't keep up with the fluid loss. So sodium levels skyrocket. This is why monitoring urine output is super important for patients at risk for hypernatremia.

 Alright, so let's say you're in clinicals and you have a 76 year old patient who came into the hospital with weakness and confusion. You check their vitals. Uh, the heart rate is 110, which is tachycardia. Blood pressure is 98 over 65, so a little low. Temperature is 100. 8. You notice their lips are cracked, their skin looks dry, and they keep asking for water.

 What are you thinking?  Could it be an infection? Maybe they're just tired? Or could this be hypernatremia caused by dehydration? You check their labs, and sure enough, their sodium is 150.

 So how do we fix hypernatremia? Your first instinct might be to give them tons of water right away. But hold up. Rehydration has to be done carefully, and here's why. If you drop sodium levels too fast, the brain can swell, leading to life threatening cerebral edema. Brain swelling. So here's the game plan instead.

Number one, you want to start fluid replacement, but go slow. In mild cases, just oral fluids like water or electrolyte solutions. In more severe cases, They're going to need IV fluids, such as a hypotonic solution, like half normal saline or D5W. The second thing you want to do is monitor the neuro status closely.

Mental status changes can sneak up on you, so you need to be checking on your patient frequently. And then third, keep an eye on that urine output. If the patient has diabetes insipidus, they might need Desmopressin to help their body hold onto water.

The key takeaway in hypernatremia is too much sodium, not enough water. Look for thirst, dry mucous membranes, restlessness, and confusion. And then fix it with fluids, but be careful not to drop sodium levels too fast. Alright, let's do another pod quiz to test your hypernatremia knowledge. I'll read the question and the answer choices, then give you a few seconds to think.

Question number one. What's the number one most common cause of hypernatremia?  A. Dehydration.  B. Eating too much salty food.  C. SIADH or D. Low potassium levels. Take a second to think.

 The correct answer is A. Dehydration. Remember, hypernatremia happens when there's too much sodium and not enough water. And what's the easiest way to lose water? Dehydration. This is especially dangerous in older adults because they have a weakened thirst response, meaning they might not even realize when they're dehydrated.

Other causes include fever, excessive sweating, vomiting, and diarrhea, all of which make the body lose fluid.

 Alright, question number two. Why is diabetes insipidus dangerous?  A. It causes severe dehydration.  B. It leads to dangerously low blood sugar.  C. It causes too much insulin production. Or D. It makes the body retain too much fluid.

 The correct answer is A. It causes severe dehydration. Diabetes insipidus is a condition where the body dumps huge amounts of water through excessive urination, sometimes liters and liters per day. Even if a patient drinks a ton of water, they still can't keep up with the fluid loss, which leads to severe dehydration and dangerously high sodium levels.

A key sign of DI is the patient will have clear, diluted urine in large amounts. So always check their urine output.  Question number three. Why can't we correct hypernatremia too quickly?  A. It can cause kidney failure.  B. It can lead to dangerously low blood pressure.  C. It can cause cerebral edema, or brain swelling.

Or D. It can make the patient hyperglycemic. Think about your answer.  The correct answer is C. It can cause cerebral edema, or brain swelling. If sodium levels drop too quickly, water rushes into the brain cells, causing them to swell. This can lead to seizures, brain damage, or even death. That's why we replace fluids slowly using hypotonic IV solutions like half normal saline or D5W and monitor sodium levels closely.

Alright, so how did you do? Let's recap. Dehydration is the number one cause of hypernatremia. Diabetes insipidus is dangerous because it causes severe water loss. And correcting hypernatremia too fast can lead to brain swelling. If you got all three, awesome job. If not, no worries, just go back and review.

Alright, that wraps up part one of our deep dive into electrolytes. Today we covered sodium, how hyponatremia and hypernatremia can affect our patients and what to watch out for. But we're just getting started. Next week in part 2 we'll break down potassium, why it's such a crucial electrolyte, what happens when levels get too high or too low, And how to recognize those critical signs in your patients.

You won't want to miss it. If you found this episode helpful, please take a second to leave a review on Apple Podcasts or wherever you're listening. It helps other nursing students find the show and keeps us going with more great content. Thanks so much for spending this time with me today.

Have an amazing week, and I'll see you next time on Nursing School Week by Week.