Why is saline used for irrigation instead of water?
In: Biology
Do you mean irrigating open wounds and injuries? If so, sterile saline does not draw fluids away from wounds or actually adds fluid to an injury, so it doesn’t hamper normal healing, damage tissue, cause allergy or alter the normal bacterial flora of the skin that would allow the growth of more organisms that cause infections.
Maybe to keep the irrigation lines clean?
It more closely matches our body’s internal chemistry. In IVs if you were to use water (be it filtered or distilled or whatever) adding enough of it will cause an electrolyte imbalance. You’d end up with parts of your body that need the sodium (like red blood cells) absorbing the water, as salt will cause things to do) and expanding and possibly rupturing. This is the same reason if you’re going to need to be consuming a lot of liquid (say, doing something athletic or you’re dehydrated from being sick), something like gatorade is better because it replenishes the sodium as well).
As for wound care (irrigation), it’s the same thing. Saline more closely mimics the body’s internal chemistry. It won’t be readily absorbed into the body nor will it draw anything out of the body. However, when irrigating a wound, studies show regular water typically works just fine. I think the reason for saline is because it’s there, it’s sterile and it’s room temperature. In other words, it’s convenient. Also, momentum. It’s what the medical professionals were taught to use, it’s what they’ve always used and it works, so why change it.
Convention. Evidence so far (e.g. [Cochrane review](https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD003861.pub3/full) among others) suggests there isn’t any delay in healing/increase in infection rate when irrigating acute wounds using water vs. normal saline. The evidence could be more compelling so I’ll stick with NS preferably, but if you don’t have NS available you can use boiled/distilled tap water and achieve a comparable result.
You listed saline in your title so I’m assuming I don’t need to ELI5 that term.
Latest Answers