Backpriming, air bubbles, and tubing

[pang.matthew]

Say I backprime a 50 mL antibiotic with NS. So the primary tubing is filled with NS and there's fewer air bubbles in the tubing. If I set the machine at 50 mL, is the amount of antibiotic the patient is getting 50 mL minus the volume in the primary tubing which is filled with NS? So is it better to just prime with the antibiotic and let some medicine drip out to get rid of the air bubbles, flick the tubing until the air bubbles are gone, or backprime with NS? (I am assuming NS is compatible with whatever antibiotic I am give.)

And does anyone know approximately how many mL's are in most primary tubing sets? Thanks!

[SierraBravo]

Our primary tubing sets are ~18mL. The package will state the volume of the tubing. Assuming you have fluids running on the primary or just a KVO NS line, it makes sense to back prime the secondary to get the bubbles out. I wouldn't prime it with the antibiotic because if you spill some then the patient won't get the full dose. After backpriming and programming the pump, add the amount of the tubing set to the VTBI of the secondary and a little extra if you backprimed some NS into the secondary set. If your tubing is 18mL like ours, then you would add 18mL+another ~5mL to account for the secondary back prime. Thus, add 23mL to the VTBI of the secondary. This will inherently add time to the infusion, but that is fine if it is an antibiotic.

[ArtClassRN, ADN, RN]

Say I backprime a 50 mL antibiotic with NS. So the primary tubing is filled with NS and there's fewer air bubbles in the tubing. If I set the machine at 50 mL, is the amount of antibiotic the patient is getting 50 mL minus the volume in the primary tubing which is filled with NS?

Kinda, unless you set the pump so the primary flushes after the abx administration.

So is it better to just prime with the antibiotic and let some medicine drip out to get rid of the air bubbles, flick the tubing until the air bubbles are gone, or backprime with NS?

Either way is fine, and if you prime correctly, you shouldn't have to flick anything. As noted, I always set the pump to flush 25 ml after the abx volume is done so i have a nice primary set to use for anything I want.

And does anyone know approximately how many mL's are in most primary tubing sets? Thanks!

I always figured like 15 ml.

[Beverage]

I back prime the secondary tubing with NS then program the pump to flush 30 ml from primary bag. The antibiotics will run until it is empty then draw the flush from the primary NS so patient gets the entire dose.