Capillary Blood Glucose Monitoring
Jannah* stares clueless at the order sheet. It’s her first week as a Registered Nurse working in the hospital. Months ago, she was very confident that she knows almost everything there is to know about in nursing, she oozed with a sense of certainty that she is fully ready to face reality and leave textbooks and lectures behind. But now, she’s having second thoughts. Upon entering the “real thing”, she has come to realize that not all her past expectations about how easy nursing is, isn’t really fully true and that there are still some things she needs to learn even after she graduated.
“What am I going to do with these strips and needle-like thingy?,” she asks herself. Yes, she is aware of FBS and RBS tests, but the thought of having to perform a CBG test on her own shakes her.
Some things you need to know about CBG
Capillary Blood Glucose Monitoring or CBG monitoring as it is commonly called plays an important role in achieving levels of diabetes control which are associated with reduction in the risk of developing diabetes complications.
With CBG results to base on, treatment may be adjusted in order to better achieve the recommended blood glucose targets, such as in cases wherein diabetes is controlled by either oral medication or insulin injection for a very stable patient.
CBG monitoring may be done every 4 hours, 2 hours, etc or sometimes 2 hours before or after a meal depending on the physician’s preference and order. This is called “Pattern Monitoring” and can be helpful to make sure the best treatment is chosen and is working.
Usually, this test is indicated for patients who:
- controls their diabetes with insulin (with or without other agents)
- are poorly controlled and are being considered for insulin treatment
- are treated with Gliclazide, glimepiride, Glipizide, Tolbutamide, Glibenclamide, Repaglinide and Nateglinide since they can be at an increased risk of hypoglycaemia (blood glucose below 4 mmol/l).
- are treated with Exenatide plus Gliclazide, Glimepiride, Glipizide, Tolbutamide and Glibenclamide as they can be at an increased risk of hypoglycaemia (blood glucose below 4 mmol/l).
For outpatients who have unstable blood sugar levels or during episodes of infection or other illness, CBG monitoring may be advised.
In shorter words, CBG monitoring allows on-going assessment of diabetic control.
Nurses play a key role in both performing regular and accurate CBG monitoring and in teaching people about its use.
With a glucometer, lancet and CBG strips in hand, we, nurses may be able to estimate the amount of glucose the patient has in his blood in seconds. The CBG result will serve as a basis for adjusting treatment and medications. Like for example, whether it is advisable to give insulin injections to the patient and on how much (in units) should be given to the patient. Mostly, CBG results are relayed to the physician assigned or the resident on duty for management. They may either order to give medications to address the high glucose result or not. In other cases, sliding scales are provided by the physician and available to base upon. It is composed of a range of CBG results (such as 130-140 mg/dl) and their corresponding units of insulin (example: 2 units) to be injected to the patient using an insulin syringe.
One advantage of CBGs over urine tests is that urine tests do not tell when the glucose is low, but only when it is high, which happens at times to patients. When this time happens, medications such as Dextrose 50 50 may be ordered by the ROD.
The role of nurses in CG monitoring is not limited to performing the test and carrying out orders to address abnormalities alone. They also play a role in health teaching about how to perform the test at home. Nurses should teach the importance of regular glucose determination at home amongst diabetic persons through the use of CBG monitoring, the normal values and how to address them. Before a meal, the CBG result should be approximately 70 to 130 mg/dl of blood. After a meal, this number should be less than 180 mg/dl.
With CBG, rapid production of results may be obtained, and timely treatment and the involvement of patients with their own care may be promoted.
It is important that the nurse emphasizes that the equipment used for CBG monitoring by people with diabetes needs to be properly maintained so that the results are accurate and reliable. Also for this purpose, the nurse must teach them aseptic technique while performing the procedure such as washing hands prior to the procedure and disinfecting the site first before pricking. If the tests are not performed appropriately with care and attention to technique, the results can be flawed and dangerous.