Doseage reconstitution help

Wuzzie · Mar 7, 2019

Each vial with 20ml?

JKL33 · Mar 7, 2019

They are telling you exactly how to reconstitute each vial.

After you do that, you will have (1) g Vanco in 20 ml, and another (1) g Vanco in 20 ml.

So then what?

mzthang2260 · Mar 7, 2019

Would it be 25 ml?

if the order would have been vancomycin 1.5 g then 30 ml? Vancomycin 2g then 40 ml? If so what kind of syringe? 30 cc?

chare · Mar 7, 2019

39 minutes ago, mzthang2260 said:
Would it be 25 ml?
if the order would have been vancomycin 1.5 g then 30 ml? Vancomycin 2g then 40 ml? If so what kind of syringe? 30 cc?

Yes. Why don't you show us how you got your answer?

You could administer this volume using a 30 mL syringe, if you weren't going further dilute this prior to administration.

mzthang2260 · Mar 7, 2019

Dimensional analysis

1.25g x 40 ml then divided by 2g. Grams cancel left with 25 ml.

I am on orientation in a hospital shadowing a nurse. She had order for 1.5g pharmacy gave 2 1g vials so 2g total. Both vials read same reconstitution instructions (20 ml). She used a 10 cc syringe to draw up 10 cc dilutent which she injected into the first vial. She then drew up another 10 cc dilutent to inject into the 2nd vial. When she was done she drew up from one vial the entire amount (10 cc) then from the 2nd vial half (5 cc) did this correctly give her the ordered 1.5 g? For every order that required reconstitution she seem to just use a 10 cc syringe and to draw up 10 cc dilutent. Which threw me off cause I kept looking at the reconstitution instructions on vial. Is there something I am missing?

Wuzzie · Mar 7, 2019

18 minutes ago, mzthang2260 said:
She had order for 1.5g pharmacy gave 2 1g vials so 2g total. Both vials read same reconstitution instructions (20 ml). She used a 10 cc syringe to draw up 10 cc dilutent which she injected into the first vial. She then drew up another 10 cc dilutent to inject into the 2nd vial. When she was done she drew up from one vial the entire amount (10 cc) then from the 2nd vial half (5 cc) did this correctly give her the ordered 1.5 g? For every order that required reconstitution she seem to just use a 10 cc syringe and to draw up 10 cc dilutent. Which threw me off cause I kept looking at the reconstitution instructions on vial. Is there something I am missing?

She gave the right dose but seriously messed up the concentration. It should have been 20 ml in each vial and a total of 30ml to give 1.5 grams. Yikes!

chare · Mar 7, 2019

25 minutes ago, mzthang2260 said:
I am on orientation in a hospital shadowing a nurse. She had order for 1.5g pharmacy gave 2 1g vials so 2g total. Both vials read same reconstitution instructions (20 ml). She used a 10 cc syringe to draw up 10 cc dilutent which she injected into the first vial. She then drew up another 10 cc dilutent to inject into the 2nd vial. When she was done she drew up from one vial the entire amount (10 cc) then from the 2nd vial half (5 cc) did this correctly give her the ordered 1.5 g?

Do you think that doing this resulted in the ordered dose?

25 minutes ago, mzthang2260 said:
For every order that required reconstitution she seem to just use a 10 cc syringe and to draw up 10 cc dilutent. Which threw me off cause I kept looking at the reconstitution instructions on vial. Is there something I am missing?

Do the included reconstitution instructions state to further dilute the 1 g/20 mL prior to administration? If so, and she subsequently further dilutes to the final concentration then this should be acceptable, even though what she did was not in accordance with the included instructions.

You will encounter many nurses in your practice that include workarounds such as this. I don't recommend doing this, as such deviations increase the likeliness of an error occurring.

mzthang2260 · Mar 7, 2019

The Vancomycin vial did not say to further dilute. She then just injected into the 200/250 ml (forgot which volume) Normal saline bag to run.

chare · Mar 7, 2019

20 minutes ago, mzthang2260 said:
The Vancomycin vial did not say to further dilute. She then just injected into the 200/250 ml (forgot which volume) Normal saline bag to run.

Interesting that you are mixing Vancomycin on your unit. When I worked adults Vancomycin came premixed, with a concentration of 5 mg/mL. Working PICU now, our Vancomycin is compounded in the pharmacy with a concentration of 5 mg/mL for peripheral administration and 10 mg/mL for central administration.

mzthang2260 · Mar 7, 2019

I am coming from a nursing home where the facilities private pharmacy mix any medications that need mixing before sending. The nurse said the hospital pharmacy does not mix many medications. I also saw her with an order for streptomycin 820mg pharmacy sent her a streptomycin 1g

JKL33 · Mar 7, 2019

28 minutes ago, mzthang2260 said:
The Vancomycin vial did not say to further dilute. She then just injected into the 200/250 ml (forgot which volume) Normal saline bag to run.

The vial may not have said to further dilute it, but the package inserts explain further dilution and that the initial concentration produced by adding the diluent is not an appropriate concentration for administration and that the med must be further diluted beyond the concentration obtained with the initial reconstitution.

The package inserts go on to recommend a final concentration of no more than 5 mg/ml, with a concentration of 10 mg/ml being allowable for certain patients as mentioned below in the Pfizer labeling/insert example:

Quote
DOSAGE AND ADMINISTRATION
Infusion-related events are related to both the concentration and the rate of administration of vancomycin. Concentrations of no more than 5 mg/mL and rates of no more than 10 mg/min are recommended in adults (see also age-specific recommendations). In selected patients in need of fluid restriction, a concentration up to 10 mg/mL may be used; use of such higher concentrations may increase the risk of infusion-related events. An infusion rate of 10 mg/min or less is associated with fewer infusion-related events (see ADVERSE REACTIONS). Infusion-related events may occur, however, at any rate or concentration.

If your preceptor used a 200 ml bag and added the 15 ml (1.5g) to the 200 ml, s/he then had 215 ml total, which contained 1500 mg, for a final concentration of 6.976... mg/ml.

If your preceptor used a 250 ml bag and added the 15 ml (1.5 g), that is a final concentration of 5.66 mg/ml.

I will not speak to whether either of these are acceptable - it's really best if you get definitive information on that within your own workplace.