Glucose Oxidation Rate in TPN

[CAPharmD123]

I know the recommended rate of dextrose infusion for 24-hr TPN is 4-7 mg/kg/min (ideal <5). However, what if the same TPN is cycled over 12 hrs? What are the administration rate restrictions? Thank you!

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[farmadiazepine]

No freaking idea. I am probably the worst hospital pharmacist.

 

[RxPreceptor]

All I can remember is 4mg/kg/min MAX rate if the pt is a refeed pt/malnourished/anorexic, etc. I would think the rate would stay the same regardless of intermittent TPN. There are way too many variable parameters (Dx states, conditions, fluid status, etc.) with TPNs; you might want to double check the protocol at whatever hospital you are at or ask one of the Nutritionists

 

[KatleyS]

I know the recommended rate of dextrose infusion for 24-hr TPN is 4-7 mg/kg/min (ideal <5). However, what if the same TPN is cycled over 12 hrs? What are the administration rate restrictions? Thank you!

The rate recommendation hasn't changed. Simply calculate the total amount of Dextrose grams now infused over 12 hours (cycled over 12 hours you said). It should still not exceed 5 mg/kg/min mostly because we do not want to lead to uncontrolled hyperglycemia in a patient. I think you can generally push towards 6-7 mg/kg/min comfortably IF their FSBS's are fairly controlled AND the patient has been a long term home TPN patient. Just my two cents.

 

[gwarm01]

No freaking idea. I am probably the worst hospital pharmacist.

All you need is a subscription to UpToDate and familiarity with the ctrl-F function!

 

[CAPharmD123]

The rate recommendation hasn't changed. Simply calculate the total amount of Dextrose grams now infused over 12 hours (cycled over 12 hours you said). It should still not exceed 5 mg/kg/min mostly because we do not want to lead to uncontrolled hyperglycemia in a patient. I think you can generally push towards 6-7 mg/kg/min comfortably IF their FSBS's are fairly controlled AND the patient has been a long term home TPN patient. Just my two cents.

Thank you!!!

 

[BidingMyTime]

I know the recommended rate of dextrose infusion for 24-hr TPN is 4-7 mg/kg/min (ideal <5). However, what if the same TPN is cycled over 12 hrs? What are the administration rate restrictions? Thank you!

Why would you cycle a TPN over 12 hours? I've never heard of this, TPN's are always 24 hour bags, if there is some lab that is so out of whack that it must be changed, then a bolus of K+ or whatever would be given (or the TPN could be cut off or the rate slowed down, but I don't think I've ever seen this happened.)

 

[Dred Pirate]

Why would you cycle a TPN over 12 hours? I've never heard of this, TPN's are always 24 hour bags, if there is some lab that is so out of whack that it must be changed, then a bolus of K+ or whatever would be given (or the TPN could be cut off or the rate slowed down, but I don't think I've ever seen this happened.)

for patients that go home and live on TPN - they don't like to walk around with a bag all day - they just cycle while they sleep

 

[KatleyS]

Why would you cycle a TPN over 12 hours? I've never heard of this, TPN's are always 24 hour bags, if there is some lab that is so out of whack that it must be changed, then a bolus of K+ or whatever would be given (or the TPN could be cut off or the rate slowed down, but I don't think I've ever seen this happened.)

I can understand why you would think that way because it is very rare for someone on the in-patient side of things to have TPN cycled over 12 hours. Usually this is the home TPN patient I just mentioned who is VERY stable and if you're lucky, is already on said 12 hour cycle so you don't really have to do any adjustments other than minor tweaking of electrolytes or don't even bother and use electrolyte runs. I generally don't intervene to put someone on a 12 hour cycle. The glucose oxidation rate is most of the time exceeded beyond 5 mg/kg/min when I calculate a 12 hour cycle and the FSBS trends already look kind of iffy (because whatever brought them into the hospital has made their labs go wonky anyway).

 

[BidingMyTime]

for patients that go home and live on TPN - they don't like to walk around with a bag all day - they just cycle while they sleep

It happens pretty often honestly for patients that will chronically be in TPN

I can understand why you would think that way because it is very rare for someone on the in-patient side of things to have TPN cycled over 12 hours. Usually this is the home TPN patient I just mentioned who is VERY stable and if you're lucky, is already on said 12 hour cycle so you don't really have to do any adjustments other than minor tweaking of electrolytes or don't even bother and use electrolyte runs. I generally don't intervene to put someone on a 12 hour cycle. The glucose oxidation rate is most of the time exceeded beyond 5 mg/kg/min when I calculate a 12 hour cycle and the FSBS trends already look kind of iffy (because whatever brought them into the hospital has made their labs go wonky anyway).

Thanks for the explanation, that definitely makes sense now. I have zero experience with home IV's.