Lactated Ringer's solution or LR is an intravenous (IV) fluid you may receive if you're dehydrated, having surgery, or receiving IV medications. It's also sometimes called Ringer's lactate or sodium lactate solution.
There are several reasons why you may receive this IV fluid if you need medical care.
What they have in common
Normal saline and lactated Ringer's are two IV fluids commonly used in hospital and healthcare settings.
They're both isotonic fluids. Being isotonic means the fluids have the same osmotic pressure as blood. Osmotic pressure is a measurement of the balance of solutes (like sodium, calcium, and chloride) to solvents (like water).
Being isotonic also means that when you get IV lactated Ringer's, the solution won't cause cells to shrink or get bigger. Instead, the solution will increase the fluid volume in your body.
How they differ
Fluid manufacturers put slightly different components in normal saline compared to lactated Ringer's. These differences in particles mean that lactated Ringer's doesn't last as long in the body as normal saline does. This can be a beneficial effect to avoid fluid overload.
Also, lactated Ringer's contains the additive sodium lactate. The body metabolizes this component to something called bicarbonate. This is a 'base' that can help make the body less acidic. For this reason, some doctors use lactated Ringer's in medical conditions such as sepsis, where the body becomes very acidic.
Some research supports that lactated Ringer's may be preferred for replacing lost fluid in trauma patients compared to normal saline.
Also, normal saline has a higher chloride content. This can sometimes cause renal vasoconstriction, affecting blood flow to the kidneys. This effect usually isn't a concern unless a person gets a large amount of normal saline solution.
However, lactated Ringer's doesn't mix well with some IV solutions. Pharmacies instead mix normal saline with the following IV solutions:
- methylprednisone
- nitroglycerin
- nitroprusside
- norepinephrine
- propanolol
Because lactated Ringer's has calcium in it, some doctors don't recommend using it when a person gets a blood transfusion. The extra calcium could bind with the preservatives in blood that allow blood banks to store it. This potentially increases the risk for blood clots.
As a side note, lactated Ringer's is also slightly different from what's called simply Ringer's solution. Ringer's solution usually has sodium bicarbonate instead of sodium lactate in it. Sometimes, Ringer's solution also has more glucose (sugar) in it than lactated Ringer's.
Lactated Ringer's solution has a lot of the same electrolytes that blood naturally does.
According to B. Braun Medical, one of the companies that manufactures lactated Ringer's, every 100 milliliters of their solution includes the following:
- calcium chloride: 0.02 grams
- potassium chloride: 0.03 grams
- sodium chloride: 0.6 grams
- sodium lactate: 0.31 grams
- water
These components can vary slightly by manufacturer.
Both adults and children can receive lactated Ringer's solution. Some of the reasons why a person may get this IV solution include:
- treating dehydration
- receiving during surgery to facilitate the flow of IV medication
- restoring fluid balance after significant blood loss or burns
- keeping a vein with an IV catheter open
Lactated Ringer's is often the IV solution of choice if you have sepsis, or an infection so severe your body's acid-base balance is thrown off.
Doctors may also use lactated Ringer's as an irrigating solution. The solution is sterile (doesn't have bacteria in it when stored properly). It can therefore be used to wash out a wound.
It can also be used during surgery to irrigate the bladder or a surgical site. This helps to wash away bacteria or make a surgical site easier to see.
Manufacturers don't intend for people to drink lactated Ringer's solution. It's only meant for irrigation or IV use.
You'll receive lactated Ringer's solution in your IV. When the solution goes into the vein, it goes inside the cells as well as outside. Ideally, the solution helps to maintain or achieve fluid balance in the body.
Giving too much lactated Ringer's can cause swelling and edema. Some people have medical conditions that mean their body can't handle the extra fluid well. These conditions include:
- chronic kidney disease
- congestive heart failure
- hypoalbuminemia
- liver cirrhosis
If people with these medical conditions are getting lactated Ringer's (or any other IV fluid), a medical professional should closely monitor them to ensure they aren't getting too much fluid.
In addition to fluid overload, too much lactated Ringer's solution could affect your electrolyte levels. This includes sodium and potassium. Because there is less sodium in lactated Ringer's than there is in the blood, your sodium levels could become too low if you get too much.
The dose for lactated Ringer's depends on the circumstances. A doctor will consider factors such as your age, how much you weigh, your overall health, and how hydrated you already are.
Sometimes, a doctor may order IV fluids at a 'KVO' rate. This stands for 'keep vein open,' and is usually about 30 milliliters per hour. If you're very dehydrated, a doctor may order fluids infused at a very fast rate, such as 1,000 milliliters (1 liter) as quickly as possible.
If you have to have an IV, you may see that your IV bag reads 'lactated Ringer's.' This is a time-tested option for fluid replacement that doctors commonly prescribe. If you do receive it, you'll be monitored to make sure that you don't get too much through your IV.