Best way to push 0.5 mL med into a central line?

[Neverbefore]

Hi everyone,

I'm a new nurse.

The other day I had to give a patient 0.5 mL of benadryl IV push. He had a chest port (central line).

The benadryl was in a 1ml vial.

Here is how I did it. Please tell me if there is a better way.

I got my smallest syringe, 3ml, and drew up the 0.5 mL.

I knew I had to give the med in a 10ml syringe (since it's a central line), so I took a 10 ml syringe of normal saline, squirted out about half of it, then injected the 0.5 mL into that, (my drug guide said you can dilute it).

The thing that bothered me about this is that 0.5 mL is such a tiny amount, and it seems like by the time I inject it into the 10 mL syringe, I've already lost some just from the transfer--like some of it was probably stuck to the sides of the original syringe and needle, etc. I feel like the patient isn 't getting the full dose.

What do you think? Should I be concerned about this? What do you do?

[Altra, BSN, RN]

Take your 10mL saline flush ... squirt out 1-2mL ... attach blunt needle & draw up Benadryl into the rest of the saline ... administer through port, flushing appropriately after the med.

[Neverbefore]

Thank you for your reply,

I didn't feel comfortable drawing up 0.5 mL into the 10 mL syringe because I felt like it's not very accurate. But then, maybe I lose some of it by transferring it from the 3mL syringe, so I guess that's not so accurate either.

[Perpetual Student]

It's Benadryl, not insulin. You want it to be close, but it's not like if it's actually 24 or 26 mg instead of 25 mg there's going to be much difference to the patient. I say that not to celebrate mediocrity, but to consider that there's always some margin of error in dosing and that in this instance it's nothing to be overly alarmed about.

On the other hand, suppose it was a drug requiring extreme precision. If you're careful about how you do it (basically make sure it doesn't splash out), you should have no less accuracy when you draw up with one syringe, stick the needle deep into your flush syringe (after squirting out some to make room, then drawing the plunger back to make plenty of space to prevent it from running out the tip) and inject the appropriate amount slowly. No more should adhere to the original syringe than would if you were injecting it directly into the IV tubing, and the needle will always be full of the drug after you draw it up. You wouldn't want to draw it up, get the correct dose in your small syringe and then have to fill the needle, though. If you changed needles for whatever reason you'd need to start off with extra drug in the original syringe so that you could prime the needle.

[blondy2061h, MSN, RN]

While I always dilute benadryl, I'm curious why you say that it bring a central line it has to be in 10ml. I frequently have to push small volumes of drugs that can't be diluted, such as hydralazine, in a CVL. I do Benadryl the same say already described- push an ml out of the 10ml syringe then guesstimate 1/2ml.

[IVRUS, BSN, RN]

The BEST way to give this is to FIRST ascertain patency of the line by flushing with a 10cc syringe with NS. Once you assess that the catheter is open and free of occlusions, then use that 3cc syringe that has the one half of a cc of benadryl and give it over the time frame that it is suppose to go in over. NEVER transfer to a 10cc syringe. You risk contamination and too much waste of the small amount of the drug. The key is to always assess your line FIRST. AND, if it is not occluded, then use the appropriate syringe size to give this small amount of drug.

[netglow, ASN, RN]

See now, I wish somebody would stay firm on this. Why does this always change nurse to nurse? Seems the whole issue is if it's a danger to ever attach anything but a 10cc syringe to a CL.

[IVRUS, BSN, RN]

See now, I wish somebody would stay firm on this. Why does this always change nurse to nurse? Seems the whole issue is if it's a danger to ever attach anything but a 10cc syringe to a CL.

It IS dangerous to use a syringe smaller than a 10cc to ASCERTAIN patency... However, once the catheter has been determined to be free of occlusions, and it is patent with a free flowing blood return, give the drug into the catheter using the approriate size syringe.

[netglow, ASN, RN]

:bowingpur

Now that makes sense. Thank you!

[hiddencatRN, BSN, RN]

It's Benadryl, not insulin. You want it to be close, but it's not like if it's actually 24 or 26 mg instead of 25 mg there's going to be much difference to the patient. I say that not to celebrate mediocrity, but to consider that there's always some margin of error in dosing and that in this instance it's nothing to be overly alarmed about.

You see this in peds in particular, where dosage is based on weight. You might have a patient need a dose of 85.984 mg of tylenol. That works out to 2.687 ml, but our oral syringes measure out 2.6 or 2.8 ml so you're going to give the patient 83.2 mg or 89.6 mg. And that's not accounting for administration issues with patients who always manage to dribble out at least a teeeeeeeeny bit of the med....

[psu_213, BSN, RN]

The BEST way to give this is to FIRST ascertain patency of the line by flushing with a 10cc syringe with NS. Once you assess that the catheter is open and free of occlusions, then use that 3cc syringe that has the one half of a cc of benadryl and give it over the time frame that it is suppose to go in over. NEVER transfer to a 10cc syringe. You risk contamination and too much waste of the small amount of the drug. The key is to always assess your line FIRST. AND, if it is not occluded, then use the appropriate syringe size to give this small amount of drug.

And I think it is nearly impossible to push 0.25 mL of, say, dilaudid into any line (central or otherwise) over several minutes, so I would always dilute it. I draw that volume up with a Tb syringe and then transfer it into a 10 mL flush (once some fluid has been expelled and then the plunger pulled back for room for the dilaudid). Incidentally, I do this with 1 mL of dilaudid too, but I will put the needle right on the flush and draw up the 1 mL. While checking patency of the line is important, it is not the question that was raised by the OP.

[Morainey, BSN, RN]

It IS dangerous to use a syringe smaller than a 10cc to ASCERTAIN patency... However, once the catheter has been determined to be free of occlusions, and it is patent with a free flowing blood return, give the drug into the catheter using the approriate size syringe.

Thank you... I learned something new today!