Capillary Blood Glucose (CBG)

Assessing blood glucose should be a part of every patient with altered mentation. Concerning findings for EMS professionals include readings below 60 mg/dL, and above 500-600 mg/dL. Be familiar with the Glucometer specs supplied by your service. Sometimes you might get a reading of “LO” or “HI”, the manufacturer specs will give the ranges of blood sugar levels that fall into those categories (usually under 20 mg/dL or over 500 mg/dL)

To take a CBG:

1. Ensure proper PPE. Have a sharps container handy.
2. Identify a finger of choice – ideally off to the side of the distal tip as it tends to hurt less.
3. Clean the site using an alcohol pad & let it dry.
4. Insert test strip into monitor.
5. Communicate to your patient that they will feel a “poke”.
6. Use your department approved lancet to puncture the site and draw blood.
7. With the test strip inserted, bring the end of the test strip to the blood, and allow it to “soak up” into the strip.
8. You should have a reading within 10 seconds – record the reading.
9. Control bleeding as necessary use gauze and direct pressure.

*On rare occasion the patient’s fingers are so calloused that the lancet does not penetrate deep enough to obtain a blood sample, the patient’s ear lobe might be a good alternative to get blood sample with lancet