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newSchoolWorks.com › VoTechWorks › Health & Personal Services › Medical Assisting › Phlebotomy: Venipuncture, Capillary Collection, and Specimen Handling › Lesson 10
HLT-MEDI38-03 · Lesson 10 · 10.5 clock hours · demo

Point-of-Care Testing and Glucose Monitoring

Objective. Students perform a capillary blood glucose test using a point-of-care glucometer according to manufacturer instructions and document the result and quality control data accurately.

⚠ Pending professional review

This lesson, its worked examples and its practice questions has not yet been verified by a licensed clinician in the field or by a certification or approval body. It is a study draft and may contain errors. Do not use it to make decisions about any patient or medication. Always follow your instructor, your supervising professional, and current official references and regulations.

VoTechWorks program approval and accreditation are still in progress. Credentials are issued only by the certifying bodies named in each program, after their own exams.

What Is Point-of-Care Testing?

Point-of-care testing (POCT) means laboratory testing performed at or near the patient rather than in a central laboratory. Results are available within minutes, allowing clinicians to make faster decisions. Capillary blood glucose monitoring is one of the most common POCT procedures in ambulatory care. As a medical assistant you will perform this test, maintain the equipment, run quality control, and document everything accurately—every time.

How a Glucometer Works

A glucometer uses a small electrochemical biosensor built into each disposable test strip. When a blood sample is applied to the strip, glucose in the sample reacts with an enzyme on the strip and generates a small electrical current. The meter converts that current into a glucose reading displayed in milligrams per deciliter (mg/dL). Because each lot of strips is slightly different, most meters require you to code or calibrate the meter to each new lot, or the meter reads a chip on the strip automatically. Always check the manufacturer's instructions—using the wrong lot code is a source of error.

Quality Control: Why It Matters

Quality control (QC) is the process of testing known solutions to confirm the meter and strips are working correctly before you test a patient. QC solutions contain a known concentration of glucose. High control solution tests the upper end of the meter's reportable range; low control solution tests the lower end. Each control has an acceptable range printed on the control bottle or package insert—for example, a label might state the expected range for a high control. Results must fall within that range for the meter to be considered reliable.

You must run QC:

If a QC result is out of range, stop. Do not test patients. Troubleshoot: check strip expiration, control expiration, storage conditions, and meter cleanliness. Repeat QC. If it fails again, remove the meter from service and notify your supervisor. Document every step.

Reading the Package Insert

The manufacturer's package insert is the authoritative source for how to use the meter and strips. Before you touch a patient, you must be able to locate:

Error codes signal problems such as an insufficient blood sample, a used strip, temperature out of range, or a damaged strip. Never ignore an error code and never guess—look it up.

Performing the Capillary Fingerstick (Simulation)

In this lesson you use a simulation pad rather than a live patient. The steps mirror real practice:

1. Verify the order and patient identity. In a real setting, use at least two patient identifiers per facility policy.

2. Gather supplies. Glucometer, correct test strip lot, lancet, alcohol prep pad, gauze, gloves.

3. Perform hand hygiene and apply gloves.

4. Warm the fingertip if needed (in simulation, this step is noted but not required on the pad).

5. Clean the site with an alcohol prep pad and allow it to dry completely. Residual alcohol dilutes the sample and can give a falsely low result.

6. Insert the test strip into the meter before or after lancing, per manufacturer instruction—the strip activates the meter.

7. Pierce the simulation pad (or, in live practice, the lateral tip of the finger, avoiding the very center to reduce pain).

8. Wipe away the first drop (in live practice; on the simulation pad, apply the supplied simulated blood directly).

9. Apply the blood drop to the correct area of the strip in one smooth motion—do not smear or add more blood after the meter begins reading.

10. Read and record the result immediately.

11. Dispose of the lancet in a sharps container immediately after use. Never recap.

12. Apply gauze to the puncture site.

13. Remove gloves and perform hand hygiene.

Documentation Requirements

POCT documentation is a legal and regulatory requirement. Your POCT result form must include at minimum:

The QC log must show the date, control lot number, control level (high/low), result obtained, acceptable range, pass/fail notation, and operator ID. An entry with any required field left blank is considered incomplete and may constitute a compliance failure. In this course, incomplete QC documentation is an automatic redo.

Safety Points

Key terms8

Point-of-care testing (POCT)Diagnostic testing performed at or near the patient's location that provides rapid results without sending specimens to a central laboratory.
Quality control (QC)A process using solutions with known glucose concentrations to verify that a glucometer and test strips are producing accurate results before patient testing.
GlucometerA handheld electronic device that measures glucose concentration in a small blood sample using an electrochemical reaction on a disposable test strip.
Reportable rangeThe lowest and highest glucose values a specific glucometer can accurately measure and display; results outside this range must be reported as less than or greater than the range limits.
High and low control solutionsCommercially prepared liquids containing known glucose concentrations used to test glucometer performance at both ends of its measurement range.
Error codeAn alphanumeric message displayed by a glucometer indicating a problem such as insufficient sample volume, an expired strip, or a temperature error; each code has a specific meaning defined in the manufacturer's manual.
Capillary bloodBlood obtained from the small capillaries near the skin surface, typically by lancet puncture of a fingertip, used for bedside glucose testing.
Operator IDA unique identifier—such as initials, employee number, or login—recorded on POCT logs to document which staff member performed the test and QC run.

Worked examples4

1. A glucometer QC log shows the high control acceptable range is 180–220 mg/dL. You run the high control and the meter displays 215 mg/dL. Does QC pass?
  1. Identify the acceptable range: 180 mg/dL (low end) to 220 mg/dL (high end).
  2. Compare the result to the range: 215 mg/dL ≥ 180 mg/dL and 215 mg/dL ≤ 220 mg/dL.
  3. The result falls within the range.
Answer: Yes, QC passes. Record 215 mg/dL on the QC log and mark it as within range (Pass).
2. The low control acceptable range is 60–90 mg/dL. Your low control result is 58 mg/dL. What do you do?
  1. Compare 58 mg/dL to the range 60–90 mg/dL: 58 is below the lower limit of 60.
  2. QC has failed. Stop—do not proceed to patient testing.
  3. Troubleshoot: check strip expiration date, control solution expiration date, storage conditions, and meter cleanliness.
  4. Repeat the QC run with a fresh control aliquot and new test strip.
  5. If QC fails again, remove the meter from service and notify your supervisor.
  6. Document the out-of-range result, all troubleshooting steps taken, and the outcome on the QC log.
Answer: QC fails (58 mg/dL is below the 60 mg/dL lower limit). Do not test patients. Troubleshoot, repeat, and document all actions.
3. A glucometer's reportable range is 20–600 mg/dL. A patient result displays as 'HI.' What does this mean and what do you do?
  1. 'HI' means the glucose concentration exceeds 600 mg/dL—the upper limit of the meter's reportable range.
  2. Record the result as '>600 mg/dL (HI)' on the POCT documentation form.
  3. Do not record an exact number because the meter cannot measure accurately above its range.
  4. Immediately notify the licensed clinician—a result above reportable range is typically a critical value requiring urgent action.
  5. Document the time you reported it and to whom.
Answer: Report '>600 mg/dL' on the form and notify the clinician immediately. Do not fabricate a numeric result beyond the meter's reportable range.
4. You open a new vial of test strips mid-shift. The QC for the previous vial passed at 8 a.m. Must you repeat QC now?
  1. Recall QC rules: QC must be run when a new vial of test strips is opened, regardless of when QC was last run.
  2. New vials may have different lot characteristics, expiration dates, or storage histories.
  3. Perform both high and low QC runs with the new vial before using the strips on any patient.
Answer: Yes. Opening a new vial of test strips requires a new QC run before patient testing, even if QC passed earlier that day with a different vial.
In class: Review the glucometer manufacturer's package insert and operator manual; students complete a structured reading guide identifying calibration frequency, QC high/low ranges, error codes and their meanings, and required documentation. · Under instructor demonstration, observe a full QC run (high and low control solutions) on the glucometer, then each student independently performs a QC run and records results on a QC log, checking whether results fall within acceptable ranges before proceeding to patient testing. · Perform a fingerstick on the simulation pad, apply the blood drop correctly to a glucometer test strip, read and record the result, and complete a point-of-care result documentation form including date, time, patient identifier, result, and operator ID.
Materials: Glucometer (one per two students), test strips, high and low QC control solutions, lancets, simulation pad, alcohol prep pads, gauze, QC log forms, POCT result documentation form, manufacturer package insert
Check: Students complete a full QC run and simulated patient test; QC values must be within acceptable range (per manufacturer), and the documentation form must have zero missing required fields — incomplete QC documentation is an automatic redo.

Practice check8

Answer each question, then check it. Nothing is recorded; this is your own practice.

Clinical laboratory procedures / POCT
1. Before performing a capillary blood glucose test on a patient, a medical assistant runs QC and gets a high control result of 228 mg/dL. The acceptable range printed on the control bottle is 200–225 mg/dL. What is the correct next step?
Administrative and clinical documentation
2. Which of the following is a required element on a POCT glucose result documentation form?
Clinical laboratory procedures / POCT
3. A glucometer displays error code 'E3' after a patient fingerstick. What should the medical assistant do first?
Clinical procedures / specimen collection
4. Why must the alcohol prep pad be allowed to dry completely before applying the lancet to a patient's fingertip during a capillary glucose test?
Scope of practice / patient safety
5. A patient's capillary glucose result is critically low. What is the medical assistant's correct action regarding the result?
Clinical laboratory procedures / quality control
6. QC for a glucometer must be performed in which of the following situations?
Clinical laboratory procedures / documentation
7. A glucometer displays 'HI' for a patient's capillary glucose result. How should the medical assistant document this finding?
Infection control / occupational safety
8. Which action best demonstrates proper sharps safety during a fingerstick glucose test?
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