ELI5- Why is an iv drip so much better than drinking water?



ELI5- Why is an iv drip so much better than drinking water?

In: Biology

If you’re not feeling well it’s easy to forget to drink water. You’re too focused on whatever else is bothering you to notice you’re thirsty. IV is a guaranteed way someone will remain hydrated.

It typically isn’t. Running an IV can be a vector of infection. If doctors can get fluids in you other ways, they probably would. IVs do have some advantages though. And if they need to run it for one reason, they can leave the IV in to run it for others with minimal increased risk of infection.

An IV is a very controlled form of delivering whatever the doctor needs to your bloodstream. They can control not only what goes in, but at what speed. By bypassing the stomach, there is no risk of the patient vomiting it up. It also bypasses the liver, which anything taken orally must pass through before circulating to the rest of the body. This typically greatly reduces whatever medicine a doctor is trying to deliver to your system since your liver will try to convert it into something non-reactive.

Administering IV fluid, along with the required use of a bed pan in an inpatient setting, is an accurate way to monitor fluid intake and urine production. Physicians frequently will require the nursing staff to “Monitor I’s and O’s,” meaning they should measure and report fluid that goes in and fluid that goes out. There are many reasons this might be valuable, but most commonly it’s used to evaluate hydration or kidney function. When IV fluid is prescribed over these concerns, it’s effectiveness is measured with a hematocrit blood test. Dehydration results in an elevated hematocrit and fluid given intravenously should lower the hematocrit over time.

It depends, it isn’t always.

But if you’re throwing up/have diarrhea and can’t keep water in your stomach, an IV is a good way to rehydrate you.

I was once in the ICU after crashing my bicycle and injuring my liver, and I wasn’t allowed to eat or drink in case they needed to do emergency surgery, because you can’t have anything in your stomach during general anesthesia as you can vomit and aspirate it. So I was on an IV, and it also had antibiotics and painkillers in it. I did get a little sponge on a stick in ice water to suck on when my mouth was dry, at least.

It isn’t better unless there’s a reason for it. Some reasons may include:

– A person cannot or should not be eating/drinking at that time for medical reasons (unconscious, about to go in for surgery, severe vomiting, some injury preventing them from swallowing properly, etc).

– The line is needed to give medication (or might be needed). If a medication is best delivered slowly over a long period, the easy way to accomplish that is by mixing it in with IV saline.

– The person is seriously dehydrated. You can only absorb so much water at a time through your digestive mucosa, so IVs can help with rehydration.

– The person is hypothermic and they are being given *warmed* saline to help bring their temperature back up to normal.

Drinking water is actually much more preferred than receiving IV fluids for most people. There might be several reasons why a doctor would order IV fluids for a patient.

1) The patient is unable to safely drink fluids. Some people, particularly some elderly people, cannot eat/drink without aspirating. The only way for them to stay hydrated is with a feeding tube or IV fluids.
2) The patient is not allowed to eat/drink anything. They might have a medical condition that will be made worse with oral consumption, or they might be having surgery soon, which generally requires the patient to be NPO (nothing by mouth) for at least one night.
3) The patient’s medical condition requires strict monitoring of oral intake and output (pee). With an IV you can control and monitor exactly how much fluid is being infused.
4) The patient is severely dehydrated, so bad that they could not realistically drink enough water to rehydrate themselves.
5) The patient is receiving an IV drug that can only be infused with IV fluids running in tandem.

Part of the hospitalization process is ensuring the patient is able to care for themselves without nursing staff watching them 24/7. So doctors will usually try to wean the patient off IV fluids to ensure they can keep themselves hydrated appropriately.