02.04 Chloride-Cl (Hyperchloremia, Hypochloremia)

n this lesson we’re going to talk about Chloride. We’ll look at what it does in the body and what happens when it’s too low or too high.

First, the normal range for Chloride is 96-108 mEq/L. If you’re using the labs shorthand, you’ll see it here in this spot. Chloride is also written Cl- so we know that it is an anion because it’s negative, and it’s actually the most abundant anion in the extracellular space. It works together with sodium to help maintain fluid balance in the body - so we see it related to sodium and fluid shifts. It also binds to hydrogen to form hydrochloric acid which is stomach acid. Important things to know is that it has an INVERSE relationship with bicarb - that means that when one goes up, the other goes down and vice versa. However, it has a DIRECT relationship with sodium and potassium - so when one goes up, so do the others. So if we see hypernatremia - or a high sodium level - chance are we will also see hyperchloremia - or a high chloride level.

So, again, we’re going to look at what happens when it’s too low and too high. Let’s start with hypochloremia or low chloride - less than 96 mEq/L. Similar to hyponatremia, we can see actual losses or relative low numbers. So when we see any kind of volume overload like in CHF or Water Intoxication, we’ll see the relative chloride levels go down. We will also see this with Metabolic Alkalosis - why? What happens to Bicarb in Metabolic Alkalosis - it goes UP, right? And since they have an inverse relationship, that means the Chloride would go down. Make sure you review the Metabolic Alkalosis lesson if you need to. And then we can have some actual salt loss where our bodies are losing either sodium and chloride like in burns, sweating, GI losses like vomiting or diarrhea, and Addison’s Disease or direct chloride losses like in Cystic Fibrosis. In fact, they lose chloride through their skin and sweat glands and people will actually say their skin tastes salty! So those are your basic causes of hypochloremia.

Now, let’s look at how it presents. The truth is - hypochloremia by itself rarely produces obvious symptoms. Most of what you see is going to be related to the underlying cause or related to the concurrent hyponatremia. Remember they have a direct relationship - if chloride is low, so is sodium. Make sure you review the sodium lesson for specifics, but basically we’ll see fluid shifting out of the vessels and into the cells and tissues, we’ll see behavior changes, increased ICP, and cerebral edema, muscle weakness, and hyperactivity in the GI tract.

So the goal for treatment is going to be to correct the imbalance, and of course to treat the underlying cause. We can give IV fluids, specifically Normal Saline or 0.9% Sodium Chloride. We could even just give them table salt PO, but that’s a much slower process. The big thing to know if you’re seeing hypochloremia is that you need to look at their other labs because it is RARE for t to exist on its own - so let it be kind of a clue to you to look at your sodium, your potassium, and your bicarb!

So now, let’s look at hyperchloremia. Hyperchloremia is when the level is greater than 108 mEq/L. Again, a loss of fluids can create a relative hyperchloremia, so we could see it with dehydration. And, in the opposite case of hypochloremia, we will see hyperchloremia in metabolic acidosis because the bicarb is low. Since they have an inverse relationship, when the bicarb is low, the chloride will be high. We can also see chloride end up elevated in acute renal failure and cushing’s disease because of issues with filtration and hormone fluctuations.

Again, the alterations in chloride rarely produce symptoms themselves, but we WILL see symptoms of the hypernatremia. The main symptoms of hypernatremia are related to cellular dehydration - so that depends on which cells we’re talking about. In the brain we’ll see behavior changes, they could be confused or cranky or they could be drowsy or comatose. Or we could see outward signs of dehydration, dry mouth and thirst, dry hot skin, etc. We may also see some muscle twitching and issues with cardiac contractility - make sure you check out the Sodium lesson for more details.

Our goals for treatment are going to be to correct the imbalance and treat the underlying cause. We can also give bicarb because we know that as bicarb goes up, chloride comes down. We want to avoid giving sodium or chloride, so we’ll use LR instead of Normal Saline - check out the isotonic solutions lesson to learn more about these IV fluids. And again, make sure you’re looking at other labs, because the chances of this being the only abnormality are pretty slim.
Okay, so let’s recap. Normal value of chloride is 96-108 mEq/L. The main functions of chloride are to help sodium balance fluid and electrolytes and to create stomach acid. Make sure you remember the indirect relationship with bicarb. Causes of hypochloremia are things like alkalosis or actual loss of sodium chloride, and it presents the same as hyponatremia. Our big goals for treatment are going to be to replace that sodium and chloride, usually with IV fluids like Normal Saline. Causes of hyperchloremia are things like acidosis or dehydration and it presents the same as hypernatremia because of that direct relationship with sodium. We can give bicarb or we can just be sure to restrict sodium and chloride intake. Our big priorities are going to be to treat the underlying cause and to make sure we’re looking at all their labs because chloride will almost never be the only electrolyte abnormality present.

That’s it for chloride, I hope this was helpful. Don’t miss all of our other electrolyte lessons and make sure you check out all the resources attached to this lesson. Now, go out and be your best selves today. And, as always, happy nursing!!