Reply To: HD MTX completion

  • Catherine Buskmiller

    November 13, 2019 at 5:26 pm

    At my hospital we also have a good amount of titrations (pretty much every time I’ve given it I’ve needed to go up at least 10% to get it all in within the 24 hours). It’s difficult to know exactly how much to titrate up given that oftentimes our rates that were infusing are <10mL/hr so even a slight difference in volume can make a pretty significant difference that isn’t completely noticeable until the last amount of medication is in the drip chamber. I know we’re know reporting to a particular pharmacist when we have to go above 10% the original ordered rate and she’ll be investigating causes.

    At times slight interruptions can come from incompatible meds (pausing during their infusion) and now we are checking a level at 23.5 hrs which interrupts it for a little bit, but even times where we haven’t had to do that it hasn’t been perfectly infusing within 24 hours. I think the problem comes from the pharmacy preparing the medication by weight instead of by volume, and while the amounts come close, they don’t come quite close enough when you’re infusing at a rate of 7.5mL/hr. 

    Catherine Buskmiller, BSN,RN
    Dallas, TX
    United States
    Original Message:
    Sent: 11-13-2019 05:13 PM
    From: Kelly Horn
    Subject: HD MTX completion

    We used to weigh our bags of HD MTX + bicarb fluids (we called them big berthas) and we had a relatively small number of issues when weighing.  We also had an order that we could increase or decrease rate by 20% in order to get it to complete in time.  We had to do some adjusting at times, but not much.  When our pharmacists found out we were weighing the bags, they made us stop and we have had nothing but trouble since getting it to finish in 23.5 hours. For 2 years we have been titrating the 24 MTX bags to get them to complete–many titrations–too many. Had to make a change.

    Now, our new process for administering HD MTX for the 24 hour infusion is that the 30 min loading dose is sent in a syringe if < 50 mls which is great, no issues.  Then the 23.5 portion is sent in primary tubing, circle primed with drug in the pharmacy, to be bifused with the sodium bicarb fluids.  We set the pump for 30mls less to account for the tubing so that we can insert the flush into the side port of the set, add the 30mls flush VTBI and it should be done in the prescribed amount of time…only it never is. Pharmacy says they are sending the exact amount of volume and calculate the rate for that total volume for 24 hours. The bicarb runs fine, but we always have to increase the rate of the MTX to get it to finish.

    We also do this for 4 hour HD MTX. Same process.  The bicarb will finish in 4 hours, the MTX has volume left in bag.

    Has anyone else had this experience?  We can’t figure out what is wrong.

    Any help/ideas would be appreciated.

    Kelly Horn, MSN, RN, CPON
    Nursing Professional Development
    McLane Children’s Baylor Scott & White Health
    Temple, TX 76502