Different Piggyback Antibiotics, Same IV Tubing?? - page 6

by RachelRN89 20,497 Views | 61 Comments

Hey all, I just had a quick question about something I was taught in nursing school and was wondering if you learned the same thing, or practice this yourself. You have 2 different IV piggyback antibiotics (compatible or... Read More


  1. 3
    I think some people are incorrectly seeing this as weighing two different risks, when really it's a pretty straightforward decision. Numerous studies have found a clinically significant risk to every connection manipulation, yet there's no measurable risk in terms of compatibility. In other words; changing tubing for different antibiotics, even incompatible ones, creates only risk for the patient and yet provides no benefit.

    One thing to remember about antibiotic compatibility is that it's concentration based. The dilution caused by even a half-hearted backflush is enough to negate any compatibility issues. The practice of changing the secondary tubing is also poorly thought through. Remember, the antibiotic also flows through the primary tubing at the same concentration and is then only flushed with fluid, just like what happens with a backflush, yet the primary tubing doesn't need to be changed (if people are doing that too then that's even worse practice). Same goes for the IV itself which is only flushed, or more accurately thoroughly diluted, between incompatible meds.

    It's unlikely we'll ever see RCT's on this topic. There's not a single RCT proving it's safer to jump out of an airplane with a parachute than without, although that doesn't mean I don't have enough information to make a well-supported decision, which is what best practice is.
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  2. 0
    Quote from redhead_NURSE98!
    Why, because you say so? Your authority apparently does not extend to my facility.
    No, you maybe misunderstand. I agree with the right use of back-priming. I am just saying that I have never worked anywhere where pharmacy would be cool with using a line with something that was incompatible, even if its flushed through.
  3. 2
    Quote from MunoRN
    I think some people are incorrectly seeing this as weighing two different risks, when really it's a pretty straightforward decision. Numerous studies have found a clinically significant risk to every connection manipulation, yet there's no measurable risk in terms of compatibility. In other words; changing tubing for different antibiotics, even incompatible ones, creates only risk for the patient and yet provides no benefit.

    One thing to remember about antibiotic compatibility is that it's concentration based. The dilution caused by even a half-hearted backflush is enough to negate any compatibility issues. The practice of changing the secondary tubing is also poorly thought through. Remember, the antibiotic also flows through the primary tubing at the same concentration and is then only flushed with fluid, just like what happens with a backflush, yet the primary tubing doesn't need to be changed (if people are doing that too then that's even worse practice). Same goes for the IV itself which is only flushed, or more accurately thoroughly diluted, between incompatible meds.

    It's unlikely we'll ever see RCT's on this topic. There's not a single RCT proving it's safer to jump out of an airplane with a parachute than without, although that doesn't mean I don't have enough information to make a well-supported decision, which is what best practice is.


    Munro and redhead,

    I have seen lines of where residual of incompatible medications have been problematic for patients.

    Seriously, lol how are you scientifically defining "half-hearted." The calcium and ceftriaxone event in babies (see below) is at odds with your dubious null hypothesis.

    Also, in many places, the secondary line is to be brought up ^, while the primary line is to be brought down V, if intermittent. Now where there are many controllers or pumps, the pump to the primary line is set at a particular rate, if continuous. So if the secondary medication is running in at the lower port on the line and at a slower rate, wouldn't this pretty much prevent any backup into the primary line. As far as the primary line, lower down, if the the primary continuous infusion is running and the secondary port is lower down, then the primary IV solution will continuously be pushing it along the IV. It is at a continuous and controlled amount, not at a guess of something that may or may not be "half-hearted." See what I mean? Physics will prevent a stagnate residual accumulation, so long as there is no serious issues of viscosity or differences in pH compatibility or other issues and problems regarding incompatibility--which begs the question, why add on something to the primary line a medication is considered incompatible, to whatever degree, at all?

    As far as compatibility between various meds going into the secondary line, my concern then has more to do with the secondary line and what it means in terms of an acceptable level of back-flushing and residuals within that particular line and port connection. So, me? I'd first want to know if the medication I'm riding into to the primary line is truly compatible with the primary IV solution. OK, that's a no brainer. Then I want to know about any medicines I would be giving back-to-back and their compatibility. For God's sake, many of the compatibility charts or compatibility information shows "unsure or unknown" for certain agents and compatibility. We take enough chances with them, and we take enough changes in practice in general. People get busy. Crap happens. To me, if something is questionable, I would much rather pull a separate line and be safe and be down with it. Again, I'm not saying use a separate secondary for each antibx or med. I'm down with that if it's compatible with both the primary--any primary additives, and any other consecutive secondary meds. Damn, I don't think that is being at all unreasonable.

    Fortunately, with kids that are on multiple infusions, they usually have multi-ported lines. But there are times it gets tricky, and in general, it's a much more anal world, b/c too much can go wrong and there are multiple other issues. I think working pediatric critical care has overall made me a safer nurse as compared when we could be more like "cowboys" in adult critical care. Sure, more autonomy, but when I think back, it was more unnecessary risks we were taking with the adult patients.

    Anyway, back to the issue:

    It's not just an issue like with Dilantin or Diazepam, however, where precipitate in the line or the catheter or port of the a particular line can cause big problems. That's bad enough, b/c it's not so easy to just stick a new line in a patient. If you have ever witnessed it, you know what a problem it is.

    It's the fact also that some meds have bad sequelae in people b/c of issues s/a how are the agents combined, what is the combination in line of the primary infusate, and the fact that multiple meds for IV PB in one line can build up as residuals. Maybe some adults can tolerate this, but some can't and certainly children may not. There are also issues with certain meds where they are formulated in non-aqueous solvents to allow dissolution of a substance that is poorly water soluble substance in a small volume. For such formulations, dilution of the non-aqueous injection vehicle with water or saline may
    precipitate the drug.

    But from a chemistry and pharmacological standpoint, there are a number of other reasons why we shouldn't mix incompatible agents, and where we well may not know what substance or amount of the substance could potentially be a problem.



    Not too long ago there were found to be problems with IV cefriaxone and calcium administration in neonates and children. This was reported in association with deaths in infants and children by a French agency. So, these meds are now to be given with separate lines, and in children, no one should be giving an electrolyte without a two RN or RN-MD check anyway--so when you check the calculations, you should also be checking what is running where and with what. There was thereafter a stoppage of these meds in any same line in adults as well, however, I believe they are doing the secondaries again in adults, b/c there were no cases of it being a problem in adults. *shrug* Whatever.

    To me, it's an issue of potentially problematic chemistry, and it's not worth it.

    Here's another consideration. In the use of multiple meds in a line, leaving various amounts of different residuals can add to the break down of the plastics in the IV line. This could also lead to problems for the patient, if not in the short-run perhaps in the long-run with continued use.

    As far out as that may seem to some, it just makes NO sense risk the potential problem by using the same line for medications that are incompatible, even if there is back-priming.

    The questions become 1. Was the back-priming done with a sufficient volume each time? and 2. What of residuals at port points? Can anyone be sure that this will not be problematic for a patient?

    No one can be sure of these things, even if there were more evidence-based studies. Why? Well there are too many variables, and the problem of added medications (multiples) only adds to the uncontrollable variables. Studies where this could be tested sufficiently are beyond problematic for numerous reasons.

    The first rule in medicine is "Do no more harm." This is just as true in nursing and allied health. Therefore, I state, again, that using a line with drugs that are incompatible, even if flushed through, is potentially problematic, and the benefits of doing this do not outweigh the potential risks.

    What is controllable is sound technique when adding to a line.

    In general, again, I say there is no problem IF meds are compatible. So by all means, limit the needless risks associated with contamination with those meds and back-flush where and when appropriate.

    It's never, however, appropriate in my practice to mingle incompatible meds. Again, the question is, can we be sure the incompatible medication was appropriated diluted by the back-flush from the primary fluid? And are we even sure the primary fluid is compatible with all of the particular secondary meds?

    Acids and bases being what they are, I 've seen crystalization set up in ports. To me, it's not worthy having to potentially stick a person again, just b/c I 'd didn't feel like getting a new and separate line for the incompatible medication, or b/c I was worried about the $2 or $3 bucks spent on procuring and using a separate line. The benefits don't outweigh the risks to me for anything that is listed as incompatible with anything else that was given through it.
    So short of any hard data, which again, would be very difficult to come by, even with multiple studies, I'm going with that with the least probability of causing a problem, and then I will use good aseptic technique for the incompatible line, and then call it a day. Sue me.
    Here's what the following expert infusion nurse shares in terms of things in general--secondary lines and back-priming:

    "Backpriming a secondary set to use it for multiple meds is an acceptable practice as long as any medication in the primary fluid is compatible with the secondary med. Leaving the secondary set attached to the primary set is much better practice because you are not manipulating the tubing on both ends with each dose. —
    Lynn Hadaway, M.Ed., RN, BC, CRNI
    Lynn Hadaway Associates, Inc.
    126 Main Street, PO Box 10
    Milner, GA 30257

    Website Lynn Hadaway Associates, Inc.
    Blog Lynn Hadaway Associates, Inc.
    Office Phone 770

    I'm cool with what she is saying, with the added exception of not risking trouble with anything that is incompatible with the other previous meds infused. Is that overkill? I don't know. You decide for your own practice. Just as easy and safe to get a separate line for that med that is incompatible with the previous med I've given through the line. And it's definitely a No-No if there is incompatibility with the primary fluid in the same IV line. Shoot, I'd be more comfortable flushing sterile NSS after the previous med and then moving to the incompatible one; b/c at least then I have the physics of flushing the whole secondary line. If the primary was stopped during infusion, I'd flush where the secondary went in too.

    I swear, I think half the time some of these angios or other lines like PICC, etc become problematic at the site because of all the various crap we are giving, how often we are giving it, and how we are giving it. Vessels are sensitive. They aren't like top line copper tubing or even tough PVC. They are made up of collagen for heaven's sake.

    Also with regard to Lynn the infusion nurse above, it seems clear to me that that would also apply to compatibility with any added electrolytes and other substances in the primary infusion, no? People can miss this stuff though.


    Also even for back-priming, what I have read is that if multiple meds and antibiotics are used in a secondary line intermittently, the secondary then should be changed every 24 hours. If you use one line and back flush, and disconnect after each infusion, this is also considered "primary intermittent." If it is connected intermittently to a primary then it is considered a secondary intermittent & changed every 24hr.

    Aside from the issue of your particular views and judgment in terms of how you want to practice, whenever in doubt, it always pays to give pharmacy a call, and refer as well to the P&P for the unit or floor, and then too, stay on top of drug safety alerts. This another reason why nurses need their smart phone or smart devices for clinical use in the hospital. You can't always get to a free computer on your floor or unit.

    Also, the hosptial, unit, or floor policies are not always right up-to-date
    . (Not to get off topic, but this is something I always use, legitimately so, against the argument of having smart phones or smart devices in the hospital.) So my first step, other than my own smart device, is to call pharmacy, while I'm also looking up the unit standard P&P.
    All places should teach new nurses to do this upon unit/floor orientation.

    Guess my, lol, "authority" (such as it is ) is bunk though, even though it's based on 10+ hospitals--99% of them being teaching/university based hospitals, as well as >20 years CC experience.
    Last edit by samadams8 on Feb 15, '13
    Esme12 and Susie2310 like this.
  4. 2
    Quote from samadams8
    Munro and redhead,

    I have seen lines of where residual of incompatible medications have been problematic for patients.

    Seriously, lol how are you scientifically defining "half-hearted." The calcium and ceftriaxone event in babies (see below) is at odds with your dubious null hypothesis.

    Also, in many places, the secondary line is to be brought up ^, while the primary line is to be brought down V, if intermittent. Now where there are many controllers or pumps, the pump to the primary line is set at a particular rate, if continuous. So if the secondary medication is running in at the lower port on the line and at a slower rate, wouldn't this pretty much prevent any backup into the primary line. As far as the primary line, lower down, if the the primary continuous infusion is running and the secondary port is lower down, then the primary IV solution will continuously be pushing it along the IV. It is at a continuous and controlled amount, not at a guess of something that may or may not be "half-hearted." See what I mean? Physics will prevent a stagnate residual accumulation, so long as there is no serious issues of viscosity or differences in pH compatibility or other issues and problems regarding incompatibility--which begs the question, why add on something to the primary line a medication is considered incompatible, to whatever degree, at all?
    I promise I've tried to understand this paragraph but I'm still not clear what you're trying to say here.

    Quote from samadams8
    As far as compatibility between various meds going into the secondary line, my concern then has more to do with the secondary line and what it means in terms of an acceptable level of back-flushing and residuals within that particular line and port connection. So, me? I'd first want to know if the medication I'm riding into to the primary line is truly compatible with the primary IV solution. OK, that's a no brainer. Then I want to know about any medicines I would be giving back-to-back and their compatibility. For God's sake, many of the compatibility charts or compatibility information shows "unsure or unknown" for certain agents and compatibility. We take enough chances with them, and we take enough changes in practice in general. People get busy. Crap happens. To me, if something is questionable, I would much rather pull a separate line and be safe and be down with it. Again, I'm not saying use a separate secondary for each antibx or med. I'm down with that if it's compatible with both the primary--any primary additives, and any other consecutive secondary meds. Damn, I don't think that is being at all unreasonable.
    If you're unsure if two different antibiotics are compatible, then backflush the line and it's a non issue.

    Quote from samadams8
    Fortunately, with kids that are on multiple infusions, they usually have multi-ported lines. But there are times it gets tricky, and in general, it's a much more anal world, b/c too much can go wrong and there are multiple other issues. I think working pediatric critical care has overall made me a safer nurse as compared when we could be more like "cowboys" in adult critical care. Sure, more autonomy, but when I think back, it was more unnecessary risks we were taking with the adult patients.
    If your changing lines unnecessarily then you're taking unnecessary risks. We know from research that even when aseptic technique is used, there's a statistically significant risk of infection with each additional "break" of the system and additional connection manipulations. With central lines, this is a huge risk. The mortality rate of CLASBI's is 18%, almost 1 in 5 will die, increasing this risk without a rationale that outweighs the risk of death isn't good practice.

    Quote from samadams8
    Anyway, back to the issue:

    It's not just an issue like with Dilantin or Diazepam, however, where precipitate in the line or the catheter or port of the a particular line can cause big problems. That's bad enough, b/c it's not so easy to just stick a new line in a patient. If you have ever witnessed it, you know what a problem it is.

    It's the fact also that some meds have bad sequelae in people b/c of issues s/a how are the agents combined, what is the combination in line of the primary infusate, and the fact that multiple meds for IV PB in one line can build up as residuals. Maybe some adults can tolerate this, but some can't and certainly children may not. There are also issues with certain meds where they are formulated in non-aqueous solvents to allow dissolution of a substance that is poorly water soluble substance in a small volume. For such formulations, dilution of the non-aqueous injection vehicle with water or saline may
    precipitate the drug.

    But from a chemistry and pharmacological standpoint, there are a number of other reasons why we shouldn't mix incompatible agents, and where we well may not know what substance or amount of the substance could potentially be a problem.
    That's why we don't mix them, we flush between them. I'm getting the impression you change all the tubing including the primary?


    Quote from samadams8
    Not too long ago there were found to be problems with IV cefriaxone and calcium administration in neonates and children. This was reported in association with deaths in infants and children by a French agency. So, these meds are now to be given with separate lines, and in children, no one should be giving an electrolyte without a two RN or RN-MD check anyway--so when you check the calculations, you should also be checking what is running where and with what. There was thereafter a stoppage of these meds in any same line in adults as well, however, I believe they are doing the secondaries again in adults, b/c there were no cases of it being a problem in adults. *shrug* Whatever.

    To me, it's an issue of potentially problematic chemistry, and it's not worth it.
    Increasing the risk of death to avoid a risk that doesnt actually exist is worth it?

    Quote from samadams8
    Here's another consideration. In the use of multiple meds in a line, leaving various amounts of different residuals can add to the break down of the plastics in the IV line. This could also lead to problems for the patient, if not in the short-run perhaps in the long-run with continued use.

    As far out as that may seem to some, it just makes NO sense risk the potential problem by using the same line for medications that are incompatible, even if there is back-priming.

    The questions become 1. Was the back-priming done with a sufficient volume each time? and 2. What of residuals at port points? Can anyone be sure that this will not be problematic for a patient?

    No one can be sure of these things, even if there were more evidence-based studies. Why? Well there are too many variables, and the problem of added medications (multiples) only adds to the uncontrollable variables. Studies where this could be tested sufficiently are beyond problematic for numerous reasons.

    The first rule in medicine is "Do no more harm." This is just as true in nursing and allied health. Therefore, I state, again, that using a line with drugs that are incompatible, even if flushed through, is potentially problematic, and the benefits of doing this do not outweigh the potential risks.

    What is controllable is sound technique when adding to a line.
    Even with sound technique there is a statistically significant risk of infection. All the studies done that found the risk of infection with manipulations involved the use of aseptic technique.

    Quote from samadams8
    In general, again, I say there is no problem IF meds are compatible. So by all means, limit the needless risks associated with contamination with those meds and back-flush where and when appropriate.

    It's never, however, appropriate in my practice to mingle incompatible meds. Again, the question is, can we be sure the incompatible medication was appropriated diluted by the back-flush from the primary fluid? And are we even sure the primary fluid is compatible with all of the particular secondary meds?
    Yes, flushing between incompatible meds has been best practice for a very long time. All secondaries should be compatible with their primary fluid, although if they aren't, changing the secondary line makes no difference.
    Quote from samadams8
    Acids and bases being what they are, I 've seen crystalization set up in ports. To me, it's not worthy having to potentially stick a person again, just b/c I 'd didn't feel like getting a new and separate line for the incompatible medication, or b/c I was worried about the $2 or $3 bucks spent on procuring and using a separate line. The benefits don't outweigh the risks to me for anything that is listed as incompatible with anything else that was given through it.
    So short of any hard data, which again, would be very difficult to come by, even with multiple studies, I'm going with that with the least probability of causing a problem, and then I will use good aseptic technique for the incompatible line, and then call it a day. Sue me.
    Here's what the following expert infusion nurse shares in terms of things in general--secondary lines and back-priming:

    "Backpriming a secondary set to use it for multiple meds is an acceptable practice as long as any medication in the primary fluid is compatible with the secondary med. Leaving the secondary set attached to the primary set is much better practice because you are not manipulating the tubing on both ends with each dose. —
    Lynn Hadaway, M.Ed., RN, BC, CRNI
    Lynn Hadaway Associates, Inc.
    126 Main Street, PO Box 10
    Milner, GA 30257

    Website Lynn Hadaway Associates, Inc.
    Blog Lynn Hadaway Associates, Inc.
    Office Phone 770

    I'm cool with what she is saying, with the added exception of not risking trouble with anything that is incompatible with the other previous meds infused. Is that overkill? I don't know. You decide for your own practice. Just as easy and safe to get a separate line for that med that is incompatible with the previous med I've given through the line. And it's definitely a No-No if there is incompatibility with the primary fluid in the same IV line. Shoot, I'd be more comfortable flushing sterile NSS after the previous med and then moving to the incompatible one; b/c at least then I have the physics of flushing the whole secondary line. If the primary was stopped during infusion, I'd flush where the secondary went in too.

    I swear, I think half the time some of these angios or other lines like PICC, etc become problematic at the site because of all the various crap we are giving, how often we are giving it, and how we are giving it. Vessels are sensitive. They aren't like top line copper tubing or even tough PVC. They are made up of collagen for heaven's sake.

    Also with regard to Lynn the infusion nurse above, it seems clear to me that that would also apply to compatibility with any added electrolytes and other substances in the primary infusion, no? People can miss this stuff though.


    Also even for back-priming, what I have read is that if multiple meds and antibiotics are used in a secondary line intermittently, the secondary then should be changed every 24 hours. If you use one line and back flush, and disconnect after each infusion, this is also considered "primary intermittent." If it is connected intermittently to a primary then it is considered a secondary intermittent & changed every 24hr.

    Aside from the issue of your particular views and judgment in terms of how you want to practice, whenever in doubt, it always pays to give pharmacy a call, and refer as well to the P&P for the unit or floor, and then too, stay on top of drug safety alerts. This another reason why nurses need their smart phone or smart devices for clinical use in the hospital. You can't always get to a free computer on your floor or unit.

    Also, the hosptial, unit, or floor policies are not always right up-to-date
    . (Not to get off topic, but this is something I always use, legitimately so, against the argument of having smart phones or smart devices in the hospital.) So my first step, other than my own smart device, is to call pharmacy, while I'm also looking up the unit standard P&P.
    All places should teach new nurses to do this upon unit/floor orientation.

    Guess my, lol, "authority" (such as it is ) is bunk though, even though it's based on 10+ hospitals--99% of them being teaching/university based hospitals, as well as >20 years CC experience.
    This post from Lynn Haddaway addresses your concerns more directly:Backpriming with the primary fluids should flush all of the residual from the first dose back into the empty fluid container which is then detached. There have been no reports to my knowledge of drugs adhering to the plastic tubing and then causing drug precipitate problems. So the only real concern for compatibility issues is between the secondary med and any drugs that are admixed in the primary fluid. This could be vitamins, heparin, insulin, plus numerous other drugs. For this reason many hospitals use a bag of plain normal saline as the carrier fluid, piggybacking all meds into the saline line which is then attached to the primary line.

    Lynn Hadaway, M.Ed., RN, BC, CRNI
    www.hadawayassociates.com"



    alibee and KelRN215 like this.
  5. 1
    Quote from samadams8
    Munro and redhead,

    I have seen lines of where residual of incompatible medications have been problematic for patients.

    Seriously, lol how are you scientifically defining "half-hearted." The calcium and ceftriaxone event in babies (see below) is at odds with your dubious null hypothesis......
    Maybe you should go to law school. They are big on teaching people to say the same thing 10 different ways to make a brief so long that no judge will want to read! That was a lot of fluff to say "I've seen what incompatibility does to people and I wish to use different tubing with incompatible solutions to make sure this doesn't happen." Fine, have fun. I'll be over here backflushing the incompatibility out of my line per policy. And you're inserting arguments that don't exist, about running a secondary with incompatible primaries. No one EVER said to hang a secondary that is incompatible with the primary fluid currently running.
    Last edit by redhead_NURSE98! on Feb 16, '13
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  6. 0
    Yes, forgive me for going on so. I guess the real issue for me, in terms of overall practice, is how thoroughly are those lines being back-primed? I mean a "good amount" isn't very scientific or measureable. Different agents may require more dilution than others in order to not be problematic.

    Truth is, I haven't done the backpriming deal for a long time. Like I said, what I have used in more recent times are medfusion pumps. I mean even then we know exactly how much we are going to "wash" through the line, b/c in the units and on babies, every drop of fluid pretty much has to be strictly accounted for; b/c all kids have 24 hour fluid volume limits, and of course some kids' limits are even stricter than others. But the other day, I did a ceftriaxone infusion through a PICC, and the order and pharmacy required a different line for this kid's dose and the whole SASH as well. Get this; the fluid that had been infusing all night was simply NSS. *shrug*

    At the end of the day, you have to follow the orders (I mean if they aren't dangerous.), and then get pharmacy's take and the unit/system policy on it.

    In general, as I have previously stated, I don't have a problem with using same lines on secondaries (multiples). Again, a little concerned about the particular agent and how much is being flushed through with the back-priming.

    Other than that, if it isn't hurting anyone, yes, I think it makes more sense than wasting numerous PB lines and too frequently opening up the system given the associated concerns with potential infection.


    I like these clinical discussions. We get different perspectives on how things are done in various places. Certainly true that it isn't the same everywhere.

  7. 0
    Let's just add a bunch of secondary ports and have one for every piggyback. :sarcasm:

    ~ No One Can Make You Feel Inferior Without Your Consent -Eleanor Roosevelt ~
  8. 0
    Quote from eatmysoxRN
    Let's just add a bunch of secondary ports and have one for every piggyback. :sarcasm:

    ~ No One Can Make You Feel Inferior Without Your Consent -Eleanor Roosevelt ~


    Right. I think that most of agree that it get ridiculous to do this.
  9. 0
    I always backflush when hanging piggybacks (based on compatibilities of course). Not only does it decrease the risk of infection for patients because you are not constantly disconnecting and reconnecting tubing but you are also saving the patient money by not having to charge them for new tubing everytime you need to hang a new piggyback.
  10. 4
    If you can't backflush secondary lines between potentially incompatible IVPB meds - are you then changing the J-loop and IV catheter between every incompatible med?

    No, you flush between meds when pushing into a saline-lock, right? So, if the problem doesn't exist in the J-loop and cath, then why would it anywhere else.
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