2017 Blood Glucose Monitoring Competency
At the completion of this course, you will be able to do the following:
- Understand how to appropriately collect a capillary, venous, and arterial sample and use the HemoCue Glucose 201 Analyzer
- Understand the quality control requirements for this test
- Understand the factors that affect the accuracy of glucose results
- Describe infection control measures for blood glucose testing
- Identify normal glucose reference ranges, values that require reporting/treatment, and symptoms of hyper- and hypoglycemia
- Know where to document results and locate Point of Care testing policies
This is a 2 part competency that includes:
- Review and Competency Test. The test is located at the end of the review material.
- Running a set of LOW/HIGH controls on the analyzer
HemoCue Glucose 201 System
The HemoCue Glucose 201 system consists of two parts: a disposable microcuvette and an analyzer. The disposable microcuvette is made of plastic and contains a cavity that allows for drawing up a blood sample. The blood sample is drawn into the cavity by capillary action and is spontaneously mixed with a dry reagent that causes a chemical reaction. The microcuvette is placed in the analyzer and the reaction is measured to give a quantitative measure of the concentration of glucose in the blood sample. Capillary, venous or arterial whole blood may be used.
Fingerstick (Capillary) Collection
- The middle or ring finger should be used for sampling.
- Massage the patient’s hand to make sure it is warm and relaxed.
- Clean with an alcohol wipe and allow to air dry or wipe off with a dry, 2×2 gauze before sampling.
- Using your thumb, lightly press the finger from the top knuckle towards the tip to stimulate the blood flow towards the sampling point.
- For best blood flow and the least pain, sample at the side of the fingertip, not in the center.
- While applying light pressure towards the fingertip, puncture the finger using a sterile, single-use lancet.
- Wipe away the first 2 or 3 drops of blood.
- Re-apply light pressure towards the fingertip until another drop of blood appears.
- When the drop of blood is large enough, fill the microcuvette as outlined below.
Note: In cases of severe hypotension or peripheral circulatory failure, glucose measurement from capillary samples may be misleading and it is recommended that venous blood be used.
Venous and Arterial Blood
- The blood should be well mixed prior to performing the measurement.
- Place a drop of blood onto the cuvette packaging (or other hydrophobic surface) or obtain sample directly from the syringe.
- Fill microcuvette as outlined below.
Glucose Analyzer Testing
- The HemoCue Glucose 201 system uses Microcuvettes.
- Unopened cuvettes should be stored below 46°F. If left at room temperature, they must be used or discarded after 3 days.
Preparing the Analyzer
- Pull the cuvette holder out to the loading position.
- Press and hold the on/off button until the display is activated.
- The display shows “SELFTEST”
- After 15 seconds the display will show “READY” and three flashing dashes.
Filling the Microcuvette
- Fill the microcuvette in one continuous process.
- The microcuvette should be completely filled. Do NOT refill.
- Wipe off excess blood from the outer surface of the microcuvette with a 2×2 gauze, being careful not to touch the open end of the microcuvette.
- If air bubbles are present in the filled microcuvette, a new sample should be obtained. Small bubbles around the edges can be ignored.
- The measurement should be started as soon as possible but no later than 40 seconds after filling the cuvette.
- Place the microcuvette into the cuvette holder and gently push the cuvette holder in to its measuring position.
- During the measurement, an hourglass will be shown on the display.
- After 40-240 seconds, the glucose value is displayed.
Click on the following button to view the 10 minute HemoCue Glucose 201 training module.
- Take only the supplies needed into the patient’s room. Don’t take the supply case into the room!!
- Gloves must be worn when performing finger sticks.
- Change gloves if they become visibly contaminated with blood.
- The analyzer must be cleaned and disinfected after every use with a facility approved disinfectant wipe.
- The cuvette holder must be cleaned daily when in use with an alcohol prep pad and allowed to air dry before putting it back to its measuring position.
When do you need to run controls?
- Daily when in use
- Whenever the analyzer is dropped or damaged
- After a battery change
- Anytime the analyzer or microcuvette performance needs to be evaluated
Why do you need to run controls?
- To evaluate whether the entire testing process is performed correctly
- To evaluate whether control results are in the expected ranges or values as found in the manufacturer’s instructions
Control bottle storage
- Unopened controls must be stored in the refrigerator at 35 – 46°F.
- Unopened controls stored in the refrigerator are stable until the expiration date on the outer box and the vial.
- After opening the vial, the controls are stable for 30 days stored at 35 – 86°F. The new expiration date should be written on the outer box and the vials.
How do you run controls?
- Remove the vials from the refrigerator and allow to stand for 15 minutes at room temperature (59-86°F).
- Gently mix the vial by inverting 8-10 times before sampling.
- Do not fill the cuvette from the vial. Dispense a drop of the control liquid onto the cuvette packaging and fill the cuvette according the manufacturer’s instructions.
- Place the cuvette in the analyzer for immediate analysis.
- Wipe any excess material from the vial and the cap with a clean 2×2 gauze and recap the vial tightly.
- Consult the control package insert for expected ranges.
- If the control doesn’t perform as expected:
- Review the instructions for use to see if the test was performed correctly
- Check the expiration date and storage conditions for the control and the cuvettes
- Repeat the test
- If the control(s) still don’t perform as expected, contact technical assistance.
Glucose Analyzer Reportable Range
The measuring range of the HemoCue 201 glucose testing system is 0-444 mg/dL.
Results above 444 mg/dL will be displayed as “HHH” or “overrange”.
If results are unexpected or do not match the patient’s condition, repeat the test and consult with the anesthesiologist. Results may be verified with a lab run glucose.
Results that Require Action
Notify the anesthesiologist for blood glucose results < 80 or > 180 mg/dL.
Fasting glucose target range for an adult without diabetes = 70 – 100 mg/dL
Fasting glucose target range for an adult with diabetes = 70 – 130 mg/dL (ADA)
Hypoglycemia is characterized by abnormally low blood glucose levels, usually less than 70 mg/dL.
Signs and Symptoms of Hypoglycemia:
- Facial pallor
- Increased appetite
- Dizziness or light-headedness
- Rapid heart rate
- Tingling around mouth and tongue
- Change in level of consciousness (ranging from confusion to coma)
It is important to remember that some individuals may have hypoglycemia symptoms that occur when blood glucose levels are higher than 70 mg/dL. Also, some individuals can have a blood glucose reading below 70 mg/dL and have no symptoms.
Click on the following link to review OISC’s Hypoglycemia Protocol.
Hyperglycemia is characterized by high blood glucose levels, and doesn’t usually cause symptoms until glucose values are significantly elevated – above 200 mg/dL. Symptoms of hyperglycemia develop slowly and some individuals who’ve had diabetes for a long time may not show any symptoms.
Early Signs and Symptoms
- Frequent urination
- Increased thirst
- Blurred vision
Later Signs and Symptoms (hyperglycemia left untreated leading to ketoacidosis)
- Fruity-smelling breath
- Nausea and vomiting
- Shortness of breath
- Dry mouth
- Abdominal pain
Insulin will be administered as ordered by the anesthesiologist. Regular insulin is the only insulin stocked at OISC and can be administered by subcutaneous injection or IV.
Patients should be observed in the PACU until the possibility of hypoglycemia from perioperative administered insulin is excluded. Consult with the anesthesiologist prior to discharge.
- All blood glucose results need to be documented in the patient’s medical record.
- The following also needs to be documented on the HemoCue Glucose 201 QC Log:
- Patient’s name/DOB/MRN (sticker)
- Test results in mg/dL
- Initials of operator
- Microcuvette lot number/expiration date
- Lot number, expected range, and result of daily Low and High control
Policies and Procedures
Click on the following to review OISC’s Policies and Procedures. The policies are also located in the OISC Policy and Procedure Manual in Phase 1 Recovery.