IV Catheter -v- Finger Stick Blood Glucose

[jwiley40]

I have a question for all here, but first, a little background:

A few days ago, I had a patient that was a diabetic, type II. We had treated this patient before, but this time, instead of treat then AMA, she needed to be transported to the ED. When I reported the blood glucose results, the dr asked if it was finger stick or from IV catheter. I told him I catheter. He proceded to lambast me for my "lack of diabetic treatment intelligence" (his words) and that if I ever reported doing blood glucose testing via IV catheter again, he'd report me to the state for "improper practice." This patient was bradycardic post D-50 administration, with a rate of 40-45bpm and somnolent. Yes, I gave 0.5mg Atropine when a fluid bolus didn't help, and she turned right around. I was hestitant to give a bolus but I was following protocol.

Here is my quandry: I have watched every single paramedic that I trained under and those that I was partnered with, perform this test exactly I have. Many of these medics have years of experience. When I first started, I would perform the finger stick only to be asked why I was doing it that way. They told me there was no difference in glucose level, whether venous or capillary. I have done my research on the subject, found that, depending on what site you go to, the answer is different. I know that hospital blood glucose, when done along with the rest of lab tests, is done the same way (venous) and those test results are accepted.

I did speak with my former instructor and was told to follow my training. So, as it stands, I will start going back to what I was trained to do, finger sticks, until I can find definitive evidence as to which most appropriate.

[paramedicmike]

You haven't asked a question. You posed your quandary but not a question.

So... what's your question?

There is usually a difference between capillary and venous blood glucose. Capillary tends to run a little higher than venous. Numbers vary but most sources seem to average around a 5% higher number for capillary whole blood.

Also, when they test at the hospital they're testing plasma glucose levels and not whole blood like you do with your glucometer. So even though it's from a venous draw they're not testing whole venous blood like you do when you take a drop out of the IV. When you compare plasma glucose from the lab with capillary whole blood from a finger stick plasma glucose is higher than capillary.

What has your research shown? How will you respond to the doc the next time you're in that situation?

[ERDoc]

Gah! I can't stand hearing stories of douchy doctors. I would never fault someone for getting a sugar from a reliable method. What difference is 5% going to make? Is a sugar of 190 vs 200 going to change treatment, or a sugar of 50 vs 48? No. If I had to guess, this guy was probably IM trained. If you ever want to experience something that will make you want to pull every toenail off and pour alcohol over the wounds, round with the IM team once at your local academic center. They mentally masturbate for an hour over a potassium of 3.3 when normal is 3.5. How about we just give the 40 of KDur and move on to the next 30 pts we have to discuss for hours each!! Sorry about the sidetrack. Your response next time should be, "You are more than welcome to but good luck since it is in my protocols. Or you could check it your damn self." Then again, if you have to deal with Dr. Douche on a regular basis it may be better just to smile and wave and move on to something important.

Edited September 16, 2013 by ERDoc

[Arctickat]

The only real problem is that the glucometer we use is calibrated for capillary blood rather than venous. However, as mentioned, the variance is so slight as to be insignificant to our treatment process. I will guarantee you that if you take your glucometer and poke your index finger on one side and then on the other you will get 2 readings that are 5% apart 9 times out of 10.

[paramedicmike]

That's what I was getting at. Five percent isn't going to change anything. Unfortunately, I got sidetracked/distracted in my response and failed to make that more clear.

I do like the "Well check it your damn self" response. Although, that might fall into the "if it felt good to say it was probably the wrong thing to say" category.

[scubanurse]

The argument could be made that if you used alcohol to prep the IV site that could cause falsely high readings as well, but like the doc said...who the f cares when it's such a small difference and your clinical pathways won't change much at all.

[jwiley40]

The information I found can range from 10mg/dl to upwards of 17mg/dl above or below the normal range. That's a very wide range.

My question was just that I want to know which is better. I looked into the hospital readings and found they look at plasma, just as you stated, paramedicMike. I realized after I put this out there that I probably sounded like an idiot and people reading this are thinking "He's allowed to practice?" I'm not an idiot, but I am always looking to make myself a better provider, so if I sound like I don't know what I'm doing, let me know by giving me information that I can use.

I also researched the glucometer my service uses and it is calibrated for capillary use only, so I have to let my partners know to not get the readings from the IV cath. I have no idea what the range is on ours.

I am trying to make sure that all of my interventions are appropriate and effective. If I am taking a reading that says the result is in the normal range and in reality, it's not, then I'm failing my patient. This is why I come here. I have gathered some awesome information from this site. Talk about a wealth of information that helps!

ERdoc, I have to deal with dr on nearly every shift. Last thing I need is him calling my administrator every time I bring in a patient. And normally, he's not a douchebag. I have never had any issue with him. He's actually a fairly good doc, so that's why I was so blown away.

[Just Plain Ruff]

The information I found can range from 10mg/dl to upwards of 17mg/dl above or below the normal range. That's a very wide range.

My question was just that I want to know which is better. I looked into the hospital readings and found they look at plasma, just as you stated, paramedicMike. I realized after I put this out there that I probably sounded like an idiot and people reading this are thinking "He's allowed to practice?" I'm not an idiot, but I am always looking to make myself a better provider, so if I sound like I don't know what I'm doing, let me know by giving me information that I can use.

I also researched the glucometer my service uses and it is calibrated for capillary use only, so I have to let my partners know to not get the readings from the IV cath. I have no idea what the range is on ours.

I am trying to make sure that all of my interventions are appropriate and effective. If I am taking a reading that says the result is in the normal range and in reality, it's not, then I'm failing my patient. This is why I come here. I have gathered some awesome information from this site. Talk about a wealth of information that helps!

Holy crapola batman, this guys on a roll. Someone who actually does research on things so he can back himself up if needed. The sodium bicarb deal and now this, why aren't you teaching medics instead of workign on the street.

I would have walked away from the doc for being rude to me but then again that might get me a trip to the sup's office.

Sometimes you just have to smile and wave.

Or you could say "go ahead, but first, here's my medical directors phone number, why don't you discuss it with him".

You could also just say "thanks for the tip"

Edited September 16, 2013 by Captain ToHellWithItAll

[jwiley40]

Well, Captain....I am enrolled in a course that will certify me to teach EMT-Basic and Medic. I start Wednesday!

And when your married to a CVS ICU RN, you better know your sh**! She looks it up and so do I. We have som lively, entertaining conversations (just not in front of the civilian population like in restaurants! Nothing like inducing nausea in other patrons!) at home and with other medical providers.

[jdboyd]

First of all any good medical professional who is treating a emrgency medical patient is going to have a very good idea of the treatmeny that will be required. A blood glucose is going to be used to confirm that. The difference is minimal, it is not like you should get a reading of 200 when it is actually 40. If you have a patient with symptoms of hypoglycemia and BS in the lower limits then treat the patient. When I have had unresponsive patients with low normal or boarder line then I have give D50 slow push and/or give 1/2 the amp, watch for a change and then check a follow up finger stick. Also we would draw blood tubes for acurate and pre D50 blood sugars. As for high blood sugars, most EMS agencies don t treat it in the field. Other than giving some insilin and fluid most DRs are not going to start treatment until they have labs.