Q's: SubqB; IV solutions

[glovedgoddess]

Hello my Q's from yesterdays shifts:

1) How does a subQ butterfly work exactly? is flushing required?

2) I am confused with Hypo and Hyper tonic solutions! For example, a pt who has an infection to breast post tram and has undergone debridement and skin graft is ordered to be on D5 1/2 NS at 50. This solution is hypertonic correct? Would the Dr put this pt on a hypertonic iv solution to assist with cell wound drainage into the circulation and excretion? (is that even remotely right? I was trying to think of theory I may be way off!).

*The idea I'm confused about is I understand why a pt who is severly hydrated would be put on a hypotonic solution to hydrate the cells. However, why would someone be put on a hypertonic solution?--maybe if they have severly low blood volume I suppose... why else would they be put on hypertonic?

3) One pt had a TUPR and his bunnywrap (abd pad around member to catch any leakage) was quite saturated with sang fluid, I removed the saturated pad, cleansed the area with saline (however, would it be fine to cleanse with a washcloth and soap? I thought of that later, don't know why I thought to use saline:uhoh3:). Normally cleansing a catheter insertion site is a clean process right? But if the person has just had a TUPR or any other genitourinary surgary should it be sterile??

Also what things should we consider here? Could it be that the drainage tube is clotting off causing the lrg amount of drainage leaking around the cather site? ..however the drinage tube seem to be draining fine into the bucket.

Thank you all u lovely helpers!

[iluvivt, BSN, RN]

1. I am assuming you are referring to hypodermoclysis. There are special SQ sets which you can purchase for this specific use and some that are made for a specific therapy ,such as in SQ Vivaglobulin administration. You can however, just use an IV catheter if you do not have a SQ administration set available. You do not need to routinely flush the site as it is not in a vessel..the drug is being administered into tissue. You do however need to rotate the site and the rotation schedule depends upon the drug you are using..the volume going to the site..the pts tolerance of the administration. Usually we re-site them every 2-3 days.

2. In order to properly understand tonicity of IV fluids you need to understand the basics. The osmolality of blood plasma is 290mOsm/L. Fluid that comes close to that is considered isotonic.....higher than that is hypertonic....lower than that is hypotonic.

The tonicity of fluids infused into a patient has a direct physical effect on their fluid and electrolyte status.

Hypertonic.....increases osmotic pressure of the blood plasma ,drawing fluids from the cells. ..excessive use can cause cellular dehydration

Hypotonic.....lowers osmotic pressure,and causes fluid to invade the cells.....excessive use can lead to water intoxication.

Isotonic......cause increased extracellular fluid volume (bloodstream).which can cause circulatory overload

You will often see D5 1/2 NS used as a post op solution ...so what you have is dextrose..252mOsm/L with sodium 77meq/L so you have hypotonic saline and isotonic dextrose. This is a hydrating solution...it provides more water than is required for excretion of salt. Its a pretty safe solution to start with as you can see how a pts kidneys are functioning before you start adding electrolytes.

So here are some examples of each

Hypertonic......3 and 5 % sodium chloride....D50

Hypotonic..... 1/2 NS...1/4 NS

Isotonic.....normal saline ...Lactated Ringers

hope this helps..it can be very confusing but I find I can figure it out if I know the physiology of it...so go back to the basics and review the basic principles of fluid and electrolytes so you can fully understand it all...this will help you out so much in a clinical setting ..it will not only help you understand why an MD is ordering one thing over another.. and you can evaluate for yourself if it makes sense .......it will help you in your assessment and monitoring of that patient

[glovedgoddess]

Thanks for your reply!..The tonicity of solutions is still pretty confusing to me but I could definitely use some refreshing of the basics and how it all works.