Difference between normal saline for inj & water for inj

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Hello,

Can contributors here please explain the uses of the normal saline for inj and water for inj?

1) Which one do you use to flush a s/c or iv line?

2) Which one do you use to dilute anti biotics?

3) Which one do you use to flush a IDC?

I am confused. Some nurses use n/s for inj to flush a s/c butterfly, whereelse some nurses use water for inj to flush it...

Also , a nurse from a country uses n/s for inj to dilute medications, whereelse nurses in another country uses water for inj to dilute medications.

Help!

C. Thinking

46 Posts

Specializes in Geriatrics, Triage, Cardiac ICU.

I am a nursing student...and from what I understand from instructors is the NS is the only thing that should be used for flushing IV catheters of any kind (unless heparin is indicated). The reasoning for this is that NS is the closest in solution to body fluids.

Now mixing medications is a different matter. Compatibility is important to consider and NS is not always that best choice in mixing certain drugs. Your drug book and IV drug guide will be able to tell you what is safe to mix with what and what is not safe. Always look up the compatibility of IV drugs and mixing solutions...EVEN IF A CERTAIN SOLUTION IS ORDERED. Doctors/Pharmacists make mistakes too, and you need to make sure that the solution is not contraindicated before sending it into someones bloodstream.

So.... NS>sterile water for injection in most cases with some exception reguarding medications.

(On a side note: we were told to always note what fluids a TURP patient come out of surgery on, continually flushing the bladder and to never allow anything but NS to be hung.)

Anyway...this is my educated take on the matter.

angelique777

263 Posts

Your question was:

1) Which one do you use to flush a s/c or iv line?

2) Which one do you use to dilute anti biotics?

3) Which one do you use to flush a IDC?

1) Which one do you use to flush a s/c or iv line?

Note: I dont flush for subcutaneous injections ever. I only flush for Intravenous lines.

I use Normal Saline flushes in my IVs before and after any medication that is given IV push. (Of course unless there is a compatabilty issue which is rare but it can be the case )

I also use normal saline flushes before I begin any IV solution and after the IV solution finishes or or I use the normal saline flushes daily to maintain my heplocks

3) Which one do you use to flush a IDC?

I use Heparin for my central line as long as my patient are not allergic to heparin. Example With a PICC line I use heparin because it what is required (It is protocol) . If you dont flush with heparin your line will clog. I dont want them those central lines to clog although after a heparin flush I will usually also flush after with normal saline flush as well. I hate to lose a PICC line so I try to get to a IV solution before it completely finishs to make sure I flush right after or the line will clog with blood and what a headache that is. You dont want to have to tell your provider you lost that central line. Lord help me it happen to me once and I got chewed out and will never forget again.

2) Which one do you use to dilute anti biotics?

I been lucky because most of my antibiotics come with the liquid that I will reconstitute with already included from pharmacy and all I have to do is snap a certain section on my medication and the powder and the liguid will mix and all have have to do is invert so they will mix together.

However, in general,

What dilutent you use all depends on the medication you are giving. When in doubt I always call the pharmacist when I am working in the hospital or I will read the medication insert which will tell you how to reconstitute the medication your using.

In addition: When pharmacy not available I use my more senior nurses who I have deemed reliable and experienced as my resource person on the unit to verify any medication I am not sure how to mix. It goes with out saying I will also ask the provider however sometimes they dont know so I rely more heavily on pharmacy for these questions.

Examples,

For vaccines such as MMR and Varicela I reconstitute with sterile water

For Rocephin (Ceftriaxone) 250mg and 500mg I reconstitute with 1 ml of 1% lidocaine because it makes the injection less painful but it can be reconstituted with sterile water.

These are medications I give often but for others that you have to mix I would rely on the order the provider gives you because they will often write what the medication will be mixed with

For instance, They may order Lasix 100mg IV in 100ml of D5w given at 10cc/hr but I have also seen it mixed with normal saline for the same order. Your order will usually say what it is mixed in and when it does not I will call pharmacy to be sure before I mix.

Hope this answer your question.

Angela

KyPinkRN

283 Posts

angelique777 said:
your question was:

1) which one do you use to flush a s/c or iv line?

2) which one do you use to dilute anti biotics?

3) which one do you use to flush a idc?

1) which one do you use to flush a s/c or iv line?

note: i dont flush for subcutaneous injections ever. i only flush for intravenous lines.

i use normal saline flushes in my ivs before and after any medication that is given iv push.

i also use normal saline flushes before i begin any iv solution and after the iv solution finishes or or i use the normal saline flushes daily to maintain my heplocks

3) which one do you use to flush a idc?

i use heparin for my central line as long as my patient are not allergic to heparin. example with a picc line i use heparin because it what is required (it is protocol) . if you dont flush with heparin your line will clog. i dont want them those central lines to clog although after a heparin flush i will usually also flush after with normal saline flush as well. i hate to lose a picc line so i try to get to a iv solution before it completely finishs to make sure i flush right after or the line will clog with blood and what a headache that is. you dont want to have to tell your provider you lost that central line. lord help me it happen to me once and i got chewed out and will never forget again.

you are flushing backwards... ns first then heparin.

africanaloe

12 Posts

Specializes in ICU,ICU stepdown, Private Duty.
saulgoodman said:
Hello,

Can contributors here please explain the uses of the normal saline for inj and water for inj?

1) Which one do you use to flush a s/c or iv line?

NS.

2) Which one do you use to dilute anti biotics?

Depends on compatibility of IV.

3) Which one do you use to flush a IDC?

In my facility we use NS BID and PRN, heparin if indicated.

As a side note- I'm a pharmacy student and there's a difference between the two.

Water for injection is NOT required to be sterile but must be pyrogen free.

NS for injection is Sterile. and if it contains Benzyl alcohol and other antimicrobials its called Bacteriostatic NS for injection :twocents::twocents:

glasgow3

195 Posts

Briefly and perhaps more to the point: Both NS for injection and water for injection are made for iv administration BUT NS is isotonic while water for injection is extremely hypotonic----so hypotonic in fact that you really don't want to be injecting it by itself cause it's hemolytic.

Water for injection has to have something added to it (a solute or medications) in the proper proportion so that the mixture is more isotonic.

The NS used in premixed saline flushes is isotonic and therefore safe to inject as is.

Joana2009

2 Posts

So can flushing a cannula with water for injection cause harm?

Specializes in Vascular Access, Infusion Therapy.
Joana2009 said:
So can flushing a cannula with water for injection cause harm?

Yes. Water is hypotonic, that is why we use isotonic 0.9% normal saline.

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