Skill List > Blood Glucose Monitoring
Clinical Alert
Elsevier Clinical Skills covers the principles of this procedure. You must follow local policies and procedures regarding technique, equipment used and documentation.
Based on Nicol: Essential Nursing Skills 4E
Adapted by: John Larkin BSc(Hons) MSc GradCertNursEd RGN RCN RNT; November 2014: Professor Maggie Nicol BSc(Hons) MSc(Nursing) PGDipEd RN
Updated by: Tanya Middlehurst MSc BSc (Hons) RN
Last updated: November 2016
Blood glucose monitoring devices. (From Jamieson E M, Whyte L A, McCall J M (eds) Clinical Nursing Practices, 5th edn. Churchill Livingstone, Edinburgh.)
Learning Objective
After reading the skill overview, watching the video, following up some of the references/web sites and completing the self-test quiz you should be ready to be assessed in practice in the skill of monitoring blood glucose levels.


Blood glucose testing is a simple investigation to detect hyper- or hypoglycaemia, the main cause of which is diabetes mellitus, where the body is unable to produce sufficient insulin (Higgins 2008). Monitoring a patient’s blood glucose provides an accurate indication of how the body is controlling glucose metabolism (Dougherty et al. 2015). Diabetes UK suggests that people with diabetes should keep their blood glucose levels as near as possible to that of a person without diabetes, namely 4–7 mmol/l before meals (Diabetes UK 2016). Insulin and glucagon, both produced by the pancreas, are largely responsible for the regulation of blood glucose (Wallymahmed 2007).

The body regulates the blood glucose levels by producing insulin, the main effect of which is to lower blood glucose  (Dougherty et al. 2015). Glucose is obtained from carbohydrates, the digestion of which generates a rise in blood glucose levels (Higgins 2008). This rise in glucose stimulates the beta cells in the pancreas to release the hormone insulin, which allows the passage of glucose into the cells, thus bringing blood glucose levels back to normal. Insulin also facilitates the storage of glucose in the liver and muscles (Higgins 2008).

Conversely, if the body’s blood sugar levels fall (e.g., patient fasting), the alpha cells of the pancreas release the hormone glucagon, which stimulates the movement of stored glucose and the blood sugar level rises (Higgins 2008).

Capillary blood glucose monitoring is a convenient method for monitoring blood glucose patterns and can be useful in guiding treatment changes in patients with type 1 and type 2 diabetes, especially during periods of instability (e.g., illness or frequent hypoglycaemia) (Wallymahmed 2007). According to Dougherty et al. (2015), the following are indications for careful monitoring of a patient’s blood glucose:

  • To assist in making a diagnosis of diabetes mellitus.
  • The acute management of unstable diabetic states: diabetic ketoacidosis, hyperosmolar non-ketotic coma, and hypoglycaemia.
  • To monitor and manage the treatment of insulin-dependent diabetes mellitus (IDDM or type 1) and non-insulin dependent diabetes mellitus (NIDDM or type 2).
  • To manage patients during periods of fasting.
  • To monitor patients taking medication such as steroids and atypical antipsychotics, which can cause blood glucose to rise.
  • Specific situations that can lead to a rise in blood glucose (e.g., parenteral feeding) (Wallymahmed 2007).

Wallymahmed (2007) describes hypoglycaemia as a blood glucose level that falls below 4 mmol/l and requires prompt treatment. Causes of hypoglycaemia include missed or late meals, not eating enough, administration of too much insulin or diabetic tablets, exercise, and excessive alcohol. Common manifestations include sweating, palpations, shaking, poor concentration, and hunger. Treatment is the administration of glucose (Dougherty et al. 2015).

Hyperglycaemia is described as a high blood glucose level, consistently above 8 mmol/l (Wallymahmed 2007). This is a result of the absence or deficiency of insulin production in the body (Dougherty et al. 2015). Diabetic ketoacidosis is a serious and common condition that can arise if hyperglycaemia is not treated (Marni & Wheeler 2006). Diabetic ketoacidosis can be precipitated by infection, myocardial infarction, stroke, or physical or emotional trauma (Allwinkle & Barclay 2011).

According to Wallymahmed (2007), all hospital inpatients with diabetes require regular blood glucose monitoring because acute illness can seriously affect blood glucose levels. The frequency of monitoring will vary according to the individual patient’s clinical condition. The most common method currently in use is capillary sampling and testing at the bedside using a glucometer (Figure 1). The Medicines and Healthcare Products Regulatory Agency (MHRA 2013a) refers to this bedside testing as point of care testing (POCT) and defines it as any analytical test that is performed for a patient by a healthcare professional outside the laboratory setting.

Wallymahmed (2007) states that all staff performing capillary blood glucose monitoring should be trained and assessed according to Trust policy, and must be aware of the expected results and when to seek medical advice. More recently, the MHRA (2013b) has stated that all staff who undertake blood glucose testing should have their training and competence established and recorded. Higgins (2008)  states that systems should be in place to ensure that any devices used are subject to quality control procedures, the frequency of which should be in accordance with manufacturer’s recommendations.

Preparation and safety

  • Explain the procedure, to gain consent and cooperation.
  • The patient’s hands should be clean, and washing the hands in warm water will encourage blood flow. Taking time to encourage blood flow before pricking the finger will reduce the need for pricking again, which can be distressing for the patient.
  • If the patient is unable to wash their hands, Nicol et al. (2012) say that the finger should be washed or wiped with a wet swab or tissue, and that alcohol swabs must not be used, as this may give a false reading.
  • Ask the patient to choose the finger to be used for the procedure. The site should be rotated because even the side of the finger can become painful if the procedure is performed several times a day (Nicol et al. 2012). The thumb and index finger should be avoided when possible as these are ‘grippers’.
  • Most Trusts require nurses to attend formal training in the use of the glucometer and may require a bar code to operate the glucometer.
  • The hands and glucometer must be clean, and apron and gloves should be worn.
  • Gather equipment required: glucose monitoring device, quality control solutions, test strips, disposable lancet, gauze or tissue, sharps disposal box, and relevant patient documentation.
  • Additional protective clothing may be necessary if indicated by the patient’s condition.
  • Check any manufacturer’s recommendations for the product. Perform and document quality assurance procedures. Wallymahmed (2007) states the following should be checked:
    • the test strips are in date, have been stored correctly, and have not been exposed to the air (this does not apply to test strips that are individually wrapped)
    • the monitor is calibrated for use with the pack of strips in use (some meters calibrate automatically)
    • if a new pack of strips is required, ensure the machine is recalibrated
    • quality control tests (high and low) have been carried out and documented in line with hospital policy and manufacturer’s instructions.


  1. Ensure that the quality assurance procedures are carried out in line with manufacturer’s instructions and hospital policy.
    Rationale – To reduce the risk of error and ensure maximum efficiency.
  2. Ensure all equipment is within easy reach and the patient is comfortable, either sitting or lying.
    Rationale – To reduce anxiety and ensure the patient’s comfort and safety.
  3. Explain the procedure to the patient.
    Rationale – To inform the patient about the procedure and to gain consent.
  4. Wash your hands and put on gloves and plastic apron. Ensure the glucometer is clean and has been disinfected.
    Rationale – To prevent cross-infection and reduce the risk of contamination.
  5. Turn on the glucometer. Check the expiry date and code number of the testing strips.
    Rationale – To ensure efficiency.
  6. Touching only the middle of the strip, remove one and insert it into the glucometer. The number shown must correlate with the number on the container. 
    Rationale – To prevent contamination and ensure accuracy.
  7. Ask the patient to indicate which finger they would like to be used.
    Rationale – To avoid overuse of any one site and thus reduce discomfort for the patient.
  8. Clean the finger with a wet swab and allow to dry.
    Rationale – To ensure that skin surface is clean and avoid dilution.
  9. Hold the hand downwards to encourage blood flow and use the disposable lancet to prick the side of the finger.
    Rationale – The side of the finger is used as it is less painful and easier to obtain a hanging droplet of blood.
  10. Wait for a drop of blood to form. Do not ‘milk’ blood into the finger.
    Rationale – Milking the finger may lead to the local blood composition being disturbed by intermingling with tissue fluid.
  11. Allow a drop of blood to fall onto the testing strip; do not smear.
    Rationale – To ensure even coverage of the strip and to obtain an accurate blood glucose measurement.
  12. Dispose of the lancet in the sharps disposal box.
    Rationale – To reduce the risk of a needlestick injury.
  13. Ask the patient to press on the site, using the swab until the bleeding has stopped. 
    Rationale – To reduce the risk of bruising.
  14. After a few seconds, the meter will provide a digital display of the result.
    Rationale – According to manufacturer’s instructions.
  15. Check that the bleeding has stopped.
    Rationale – To ensure that the patient is comfortable.
  16. Read the result on the glucose meter and document the blood glucose level according to local policy.
    Rationale – To ensure accurate recording of results.  Local policy usually requires your signature, the date and time of the test, and the lot number and expiry date of testing strips.
  17. Dispose of waste (e.g., gloves, cotton wool, or gauze) appropriately and perform hand hygiene.
    Rationale – To reduce the risk of cross-infection.
  18. Report any unexpected result or out of range result to the nurse in charge.
    Rationale – To ensure patient safety and determine appropriate action. 
  19. Disinfect the glucometer according to local policy.
    Rationale – To prevent cross infection.
  20. Return the glucometer to the storage area.
    Rationale – To ensure it is readily available for the next use.

Ongoing care, monitoring and support

  • Ensure the patient is comfortable.
  • Inform the patient of their blood glucose level.
  • Ensure bleeding has stopped.
  • Dispose of all sharps and contaminated waste in the appropriate containers.
  • Remove gloves and apron and wash hands.

Documentation and reporting

  • Documentation and reporting must be in line with local policy. Local policy usually requires your signature, date and time of the test, lot number and expiry date of testing strips. 
  • According to the Nursing and Midwifery Council, nurses should keep clear and accurate records which are relevant to their practice, completing them accurately and as soon as possible after an event (NMC 2015).
  • In addition, they state that the nurse must identify any problems that have arisen and how they have been dealt with (NMC 2015).

  • The National Institute for Health and Clinical Excellence (NICE) has stated that physiological ‘track and trigger systems’ such as Early Warning Scores (EWS) should be used to monitor all adult patients in acute hospital settings (NICE 2007).

  • Through documentation, registered nurses communicate to other nurses and members of the multidisciplinary team their assessment about the status of the patient.

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