How to Monitor Blood Glucose
Assistant Professor, Al Qamar College of Nursing Kalaburagi 585104 Karnataka.
*Corresponding Author E-mail: maheboob247@gmail.com
Blood glucose testing provides important information about the effectiveness of the diabetes management plan and assists nurses to monitor the clinical situation and take appropriate action. Nurses should consider the rationale for performing a blood glucose test every time they test a patient’s blood glucose level and commit to acting on the results, including whether the results are abnormal for the patient.
KEYWORDS: Blood Glucose, Blood Glucose Monitoring, Clinical Procedures, Clinical Skills, Diabetes, Hyperglycaemia, Hypoglycaemia.
Capillary blood glucose monitoring is an essential component of diabetes care. Blood glucose tests provide important information about how the body is controlling blood glucose metabolism, and the effect of glucose- lowering medicines, illness and stress.
The nurse should consider the rationale for testing blood glucose each time they perform a test, and reflect on the result, taking into consideration the patient’s blood glucose target range and recommended care guidelines.
Blood glucose testing times and testing frequency should be planned to suit the glucose-lowering medicine regimen and the clinical situation.
The nurse should only perform blood glucose monitoring if they:
· Have been trained to take the blood glucose testing technique.
· Are able to interpret the results when the context of the patient’s situation and health status and act on these results.
The nurse should understand normal glucose homeostasis, the normal glucose range, factors that affect glucose homeostasis and the action of glucose- lowering medicines. They should be able to recognise hypoglycaemia and hyperglycaemia, and know how to treat these complications. They should be able to detect changes in the patient’s blood glucose pattern and identify potential underlying causes of these changes.
Blood glucose meters should meet the International Organization for Standardization (2013) standard 15197:2013, be appropriately maintained and control tested regularly to ensure they provide accurate results within the reference ranges defined by the manufacturers.
Blood glucose test strips must be stored in the manufacturer’s closed containers and away from heat, light and moisture.
· Gloves.
· A blood glucose meter, correctly calibrated.
· Test strips, appropriate for the blood glucose meter.
· A lancet and lancing device, or a disposable device.
· Access to soap and warm water.
· A cotton or gauze swab.
· A sharps container.
· A clinical waste container.
· The patient’s blood glucose chart and/or medical record to document the result.
· The nurse should explain the procedure to the patient and obtain informed verbal consent.
Capillary blood glucose monitoring is an essential component of diabetes care.
Nurses should understand normal glucose homeostasis, the normal glucose range (usually between 3.5-6.5 mmol/L), factors that affect glucose homeostasis, action of glucose-lowering medicines and should be able to recognise hypoglycaemia and hyperglycaemia.
The test strips are sensitive to heat, moisture and light and so should be stored in closed containers.
1. Ask the patient to wash their hands or help them to do so, if necessary. Ask the patient to sit or lie down.
2. Wash your hands and put on the gloves.
3. Load the lancet into the lancing device.
4. Remove a test strip from its container and insert it into the blood glucose meter.
5. Clean the site on the finger where the test will be performed to remove any residual glucose from food. Ensure the skin is dry.
Figure 1. Taking a blood sample using a lancet
6. Use the lancet to pierce the skin at the side of the finger to obtain a blood sample (Figure 1). Do not pierce the pads of the fingers because they can become sore. It is easier to obtain a drop of blood if the hands are warm. Encourage bleeding by ‘hanging the arm’, if necessary, to enable gravity to aid blood flow. Avoid squeezing the finger because it dilutes the red blood cells with plasma and could affect the result. Choose a different finger for each test.
Figure 2. Applying a blood sample to the test strip on a blood glucose monitor
7. Apply the drop of blood to the reagent pad on the test strip or allow capillary action to draw the blood into the test strip (Figure 2).
8. Apply the cotton or gauze swab to the puncture site to stop the bleeding. The bleeding usually stops quickly, but it can take longer when the patient is taking anticoagulant medicines.
9. Dispose of the used lancet in the sharps container.
10. Dispose of the used cotton or gauze swab and gloves in the clinical waste container.
11. Record the blood glucose level in the patient’s blood glucose chart and/or medical record.
12. Inform the patient with diabetes of the result.
13. Decide whether the blood glucose level is consistent with the patient’s clinical situation, and whether it is within their target range.
14. Take steps to manage hypoglycaemia or
hyperglycaemia, if appropriate. Check the emerging blood glucose pattern to note recurrent hypoglycaemia or hyperglycaemia, and attempt to determine the underlying cause for test results outside the patient’s target range.
15. Report the findings to the relevant healthcare professionals in your organisation.
16. Ensure the blood glucose meter and other equipment are clean and return to the usual storage location.
Blood glucose levels usually remain within a narrow range (3.5-6.5mmol/L) through the opposing actions of insulin, an anabolic hormone that lowers blood glucose, and the catabolic catecholamine hormones – glucagon, cortisol and growth hormone that increase blood glucose (Dunning 2014). Insulin release is stimulated when glucose enters the bloodstream after a meal (fed state) and assists glucose entry into cells where it is used for energy. As the glucose is used, catecholamines stimulate glucose release from liver and muscle cells to maintain the glucose level in the bloodstream within the normal range (fasting state).
Insulin is released in two phases. The first phase is important to control post-prandial blood glucose, but first-phase insulin secretion is lost early in the course of type 2 diabetes (Dornhorst 2001). High post-prandial blood glucose is a feature of type 2 diabetes and is associated with an increased risk of cardiovascular disease, cancer, cognitive impairment and other comorbidities (Ceriello 2000).
Blood glucose testing is undertaken for many reasons, including determining the effect of prescribed glucose- lowering medicines and the emerging blood glucose pattern, and detecting hypoglycaemia and hyperglycaemia (Dunning 2014, Holt 2014). Most healthcare organisations require people performing capillary blood glucose tests to wear gloves as part of infection control procedures.
Testing blood glucose 2 hours after a meal provides information about glucose clearance from the blood.
· The aim for an individual with type 1 diabetes is a blood glucose level of 4-7mmol/L before a meal and 5-9mmol/L 90 minutes after a meal (National Institute for Health and Care Excellence (NICE) 2015a).
· The aim for an individual with type 2 diabetes is a blood glucose level of 4-7mmol/L before a meal and
<8.5mmol/L 2 hours after a meal (NICE 2010).
· However, these ranges may increase the risk of hypoglycaemia in frail older people, and a range of
6-15mmol/L may be more appropriate and safer in this case (International Diabetes Federation 2013, Dunning et al 2014).
Blood glucose testing and testing frequency should be planned to suit the patient’s glucose-lowering medicine regimen and the clinical situation.
The American Diabetes Association (2003) stated that capillary blood glucose testing is ‘analogous to an additional “vital sign” for people with diabetes’. It helps nurses and patients with diabetes to identify whether most tests are within the patient’s blood glucose target range, the blood glucose pattern over time and the frequency of hypoglycaemia and hyperglycaemia, and assists decisions about the individual’s glucose-lowering medicine needs (including type, dose and dose frequency) and their diet and exercise regimen (Dunning 2014).
Testing blood glucose before and 2 hours after each meal for 3-4 days provides useful information about the patient’s blood glucose pattern (Cook et al 2007). The aim is to keep blood glucose relatively stable because glucose variability activates oxidative stress, which has adverse effects on tissues and organs and is associated with the development of complications (Monnier and Colette 2008).
For blood glucose testing to be useful, nurses and patients with diabetes should take responsibility for accurately performing, interpreting and acting on blood glucose test results (Klonoff 2008). To ensure the test is performed accurately, the site on the finger where the test is performed should be cleaned to remove any residual glucose from food that may affect the result. However, it is not necessary to use alcohol swabs to cleanse the skin; while it is unlikely that the amount of alcohol left on the finger from alcohol swabs will affect the blood glucose result, alcohol dries and toughens the skin over time (Dunning et al 1994). In addition, the sides or tips of the fingers should be used in preference to the pads of the fingers to reduce discomfort because the finger pads are highly sensitive and because the skin may become tough with repeated use, which makes it difficult to obtain a drop of blood.
blood glucose self-monitoring is an important aspect of diabetes self-care. Blood glucose self-monitoring is recommended for people with type 1 diabetes and those with type 2 diabetes treated with insulin (TREND-UK 2014, NICE 2015a, 2015b). It helps individuals to
achieve their blood glucose target range and understand when it is safe to drive, and reduces short and long-term complications (TREND-UK 2014, Canadian Diabetes Association 2015, NICE 2015a, 2015b). Glycated haemoglobin, which reflects the average blood glucose level over the preceding 3 months, is used alongside blood glucose monitoring to plan the individual’s care.
When monitoring blood glucose, the patient’s finger should not be squeezed because it dilutes the red blood cells with plasma and could affect the result.
The aim for an individual with type 1 diabetes is a blood glucose level of 4-7mmol/L before a meal and 5- 9mmol/L 90 minutes after a meal. With type 2 diabetes, the aim should be for blood glucose levels to be 4- 7mmol/L before a meal and <8.5mmol/L 2 hours after a meal.
Blood glucose self-monitoring is recommended for people with type 1 diabetes and type 2 diabetes who are being treated with insulin. It helps people to achieve their blood glucose target range and can reduce short and long-term complications.
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Received on 26.05.2021 Modified on 21.06.2021
Accepted on 10.07.2021 © AandV Publications all right reserved
Int. J. Nur. Edu. and Research. 2021; 9(4):481-484.
DOI: 10.52711/2454-2660.2021.00112