But Why? Fingersticks and Common Sense

In my hospital nurses were required to order a stat lab serum glucose whenever they had a critically High or Low Fingerstick result. My question was...Why? Nurses General Nursing Article

Ordering a Stat Serum Glucose to Confirm Glucometer (Fingerstick) Reading

This is a case where the policy did not seem to make sense.

At my facility, the blood glucose monitoring procedure called for the nurse to order a stat serum glucose in the event of a critically low or high fingerstick value.

(Critical blood glucose values at my facility are defined as less than 50 mg/dL or greater than 500 mg/dL for adults and less than 25 mg/dL or greater than 200 mg/dL for neonates).

Let's say you perform a fingerstick on your adult patient which results in a value of 48 (critically low value). According to the procedure, you would immediately call Lab for a stat serum glucose. If the patient were symptomatic, you would also immediately implement the Hypoglycemic Protocol and administer either D50 or oral carbs, depending on if they can safely swallow or not.

As an educator preparing to do competency testing at our annual Skills Fair, I, of course, planned to teach from the policy and procedure- but I have to say, this made no sense to me.

My question was "What is the rationale for ordering a stat serum glucose when the fingerstick result is critically low or high?" I asked several key people in Lab and Nursing.

Here are 3 conversations I had with various decision-makers while attempting to understand the rationale:

Conversation #1

Me: "What is the rationale for ordering a stat serum glucose when the fingerstick result is critically low or high?"

Answer: "To verify the low result"

Me: "Samples must be drawn at the same time or within a few minutes of each other to have a valid comparison. How long does it take Lab to get to the floor for a stat? Realistically?"

Answer: "For a stat? 15-30 minutes"

Me: "Right....."

Conversation #2

Me: "What is the rationale for ordering a stat serum glucose when the fingerstick result is critically low or high?"

Answer: "Well, the machine might be wrong. We have to check it"

Me: "Actually our machines are top-performing and we have the most recent model. They even correct for low hemoglobin and hematocrit. They are checked regularly by Bio-Medical Engineering and Quality Controls (QC) are performed every 24 hours. If we assume the glucometers are inaccurate perhaps we shouldn't use them on patients."

Conversation #3

Me: "What is the rationale for ordering a stat serum glucose when the fingerstick result is critically low or high?"

Answer: "We don't want to treat a patient if it's wrong"

Me: "Oh..except...wait, we do treat them based on the fingerstick results. Our protocol/policy says to treat symptomatic hypoglycemia. Are you saying we should wait for Lab to come draw and call the result before we give D50 to a symptomatic hypoglycemic patient ?"

In the end, the only real argument was 'Well... because we've always done it that way"

My colleague and fellow Educator Debbie and I embarked on a mission to change the policy. Our goal was to ensure patient safety, and to not impede nurse workflow with unnecessary interventions.

We know that blood glucose values can change quickly depending on the clinical condition of the patient. We sought out Lab's expertise and discovered that glucometer results are considered to be accurate and acceptable if the comparison serum glucose specimen s within 15 mg/dL for results less than 75 mg/dL or +20 mg/dL for glucose results greater than 74 mg/dL.

We re-wrote our policy accordingly. Now it reads: "If a critical value is obtained":

  • Repeat the (fingerstick) test to confirm the result
  • If test result is not confirmed, i.e., the second test value varies by more than 10%, obtain a stat Lab draw
  • Notify MD if test is confirmed and the result is outside expected parameters for that patient
  • Select or enter a relevant comment in the glucometer
  • Follow Hypoglycemia Protocol for symptomatic patients

It makes sense and allows the nurse to intervene quickly and care for his/her patient.

Take a look at your policies. If they don't add value, don't help patients and/or aid in nurse workflow... it may be time to make a change!

Specializes in Oncology.
If we have a critical high or low, we retest and treat. I have 2 T1 sons. If i waited 15-30 minutes to treat a low, they could end up in a coma. We retest and treat, symptomatic or not (for lows). Always treat for the low immediately.

For highs they treat, if it is over 500, they are going on an insulin gtt. Our high to notify provider is 350/lows

I don't deal with a lot of adults with DKA b/c they would be in ICU. My son was in PICU for dka 2 weeks ago, they test for ketones every void test BG every hour while on insulin gtt.

I am at very large teaching hosp. Even a stat blood test would take too long. two fingersticks would be enough.

You don't wait for the results to treat when this is the policy

Specializes in LTC, Rehab.

Another factor that I want to point out, and I've discovered that some co-workers didn't know this, is that if the patient has been touching food with the finger you're sticking - even if you can't SEE any food residue on the finger - it can affect the number. Any time anyone is 'crazy high' I clean the finger more thoroughly with another alcohol wipe, OR use the other hand, and only if that second result is still crazy high, do I accept that as a valid result. Sometimes it is, but other times it's 100 points lower!

Specializes in ICU, trauma.

our glucometers dont read below 40 and above 500. When i had a patient who had a blood sugar of 1800 and a q1 insulin drip it was a pain in my rear. Especially because by the time lab came and drew + resulting time i was already an hour behind

My aide checked the fingerstivk and got 20. She rechecked immediately and called me with an 11. She checked it again while I quickly assessed patient and it was 25. Patient was very lethargic, barely able to arouse. I go to pull D50, no order, just subcutaneous glucagon-which had to be sent up from pharmacy. So, I call pharmacy as I race down to grab the med, page doc, and have secretary put in for stat lab draw. During these ten minutes the lab arrived while I have to mix the medication to give. Now they're drenched in sweat. I quickly give the med and as I'm scanning it in the doc calls back, orders the D50 on top of it (finally). The patient was only admitted late in the prior shift so this was probably why there was no D50. I never had a diabetic without it. So I give the D50, recheck 15 minutes later, patient awake and responsive. Finger stick 230. I'll take it. Rather elevated than crazy low. An hour and a half later the lab calls with my results (kind of useless now). Stat lab value 24...and they insist it's an error....no...just no. Definitely time for a change in policy. If I was to wait for the lab, I'd be coding the patient.

We have very little standing orders in LTC except with our diabetics Totally different world than acute care, but often times we get new admits that are newly diagnosed.

A critical reading is retested via finger stick (stat labs take at least 3 hours) and then treated via standing orders. No wait time. (5 minutes tops to access the needed meds)

Specializes in school nurse.

Makes little sense to be a "stat" lab with a low sugar. You'd want to give carbs immediately for a critical low if they can eat, and by the time the lab is drawn, of course the value would be different because they've eaten...

Specializes in Tele, ICU, Staff Development.
Makes little sense to be a "stat" lab with a low sugar. You'd want to give carbs immediately for a critical low if they can eat, and by the time the lab is drawn, of course the value would be different because they've eaten...
My thinking exactly, friend!
Specializes in Oncology.

How long does it take ya'll to draw a tube?

Specializes in LTC, Rehab.
our glucometers dont read below 40 and above 500. When i had a patient who had a blood sugar of 1800 and a q1 insulin drip it was a pain in my rear. Especially because by the time lab came and drew + resulting time i was already an hour behind

Isn't that crazy? Mine don't show above 600. It has a 3-digit display, so why not show the actual number. Mine at work only says 'HI' if above 600.

I don't care what policy is, if I get a 40 on blood sugar, I'm dumping a juice down pts throat.

Specializes in ICU, CVICU, E.R..

This other facility where I do agency does not even do fingersticks in the ICU. All blood glucose level are obtained thru serum. Even patients on insulin drip get the hourly stick from lab.

Specializes in Oncology.
Isn't that crazy? Mine don't show above 600. It has a 3-digit display, so why not show the actual number. Mine at work only says 'HI' if above 600.

Because it can't accurately determine the result because of the limits of a capillary sample. Even labs at levels that high need to dilute the sample and extrapolate the result.