drugrate and infusionrate in infusiondrug table

[hhchang0210]

Hi, I am trying to understand the mearning of drugate and infusionrate in infusiondrug table. For example:

drugname: nitroglycerin (mcg/min) drugrate: 10 infusionrate: 3 drugamount: 50 volumeoffluid: 250

Does that mean drugrate is 10 mcg/min, infusionrate is 3 cc/min and drug concentration is 1/5 mcg/cc? And according to https://eicu-crd.mit.edu/eicutables/infusiondrug/, drug concentration is independent of the drugRate or infusionRate. That means if I want to calculate the amount of drug and fluid in 60 min, I just use 10 60 = 600 (mcg) and 10 3 = 30 (cc) to get them, without caring of drug concentration. Is it right?

[alistairewj]

These two fields are slightly different because they interface differently with the hospital EHR. What I understood of it is written here: https://eicu-crd.mit.edu/eicutables/infusiondrug/

Infusion drugs entered directly into the source system (eCareManager) by clinicians must include the concentration of the drug being infused. This is done by entering the “drugAmount” and “volumeOfFluid” and this is independent of the amount being infused (drugRate or infusionRate). Interfaced values from source EMRs may not contain the concentration.

@obadawi anything to add/clarify?

[obadawi]

A few things to note here:

• Concentration will generally be charted in mg and ml. So in this case, the patient has a 50 mg/250 mL bottle of NTG
• Infusion rate is generally charted as ml/hr. So this patient is receiving 3ml/hr of 50mg/mL of NTG
• Drug rate units should be specified and should match the calculation obtained from the infusion rate * concentration (which this does once you convert mg to mcg)
• Alistair is correct that many EHRs will only interface out the infusion rate so you may only get the mL/hr and it may be difficult to get the actual drug rate unless it's a standard concentration drug like 10% propofol. You can also sometimes find the exact drug name and concentration in the medication table to verify concentration.

hope this helps.

On Tue, Oct 29, 2019 at 8:30 AM Alistair Johnson notifications@github.com wrote:

These two fields are slightly different because they interface differently with the hospital EHR. What I understood of it is written here: https://eicu-crd.mit.edu/eicutables/infusiondrug/

Infusion drugs entered directly into the source system (eCareManager) by clinicians must include the concentration of the drug being infused. This is done by entering the “drugAmount” and “volumeOfFluid” and this is independent of the amount being infused (drugRate or infusionRate). Interfaced values from source EMRs may not contain the concentration.

@obadawi https://github.com/obadawi anything to add/clarify?

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[alistairewj]

Cheers @obadawi I added this as an illustrative example to the docs!

[tompollard]

@obadawi please could you give a little more detail on this point:

Drug rate units should be specified and should match the calculation obtained from the infusion rate * concentration (which this does once you convert mg to mcg)

I don't follow the bit where we go from 3ml/hr of 50mg/mL to the drug rate of 10.

[obadawi]

No problem...sorry for the confusion. Here's the breakdown:

Concentration: 50mg in 250 mL = 0.2 mg/mL Infusion rate: patient is getting 3ml/hr so that's 3ml/hr(0.2mg/mL)=0.6mg/hr Drug rate: 0.6 mg/hr divided by 60 minutes/hr = 0.01 mg/min Drug rate converted to specified units labeled as mcg/min: 0.01 mg/min 1000mcg/1mg = 10 mcg/min

[rgmark]

the problem is that the concentration is 50mg per 250cc, or 0.2 mg per cc. This would be 0.6 mg (600 mcg) per hour or 10 mcg per minute

Roger

[tompollard]

Makes sense, thanks