Therapeutic Update: Continuous Blood Glucose Monitoring

Dr. Shammy Noor Discuss the benefits and reliability of continuous blood glucose monitoring

Conventional blood glucose test
Finger prick blood tests have been used for generations. It’s convenient, accessible, and provides instant results. Disadvantages include:

• Limited information. A finger prick gives you a snapshot of how your blood sugar fluctuates throughout the day due to stress, exercise, and medications. A snapshot does not show the direction of travel. A rapidly falling blood sugar level (BG) 5 requires a different response than a stable blood sugar level (BG) 5 over time, but you can’t tell the difference by pricking your finger.
• discomfort or inconvenience. It hurts when your finger is stabbed frequently. Calluses and scar tissue build-up reduce reading accuracy.
• price. Add the cost of test strips and lancets.
  Less cost effective than continuous glucose monitoring (CGM) when used more than 6 times per day.
• User error. Failure to wash your hands before the test, not using enough blood, or not properly calibrating the meter can result in inaccurate readings.

How CGM works
A small sensor is inserted under the skin, usually in the abdomen or arm. This sensor measures glucose levels in interstitial fluid rather than capillary glucose, which is measured with a finger prick.

Sensors measure levels every few minutes and send this information to devices such as smartphones and monitors.

Flash blood glucose monitoring is a little different in that it doesn’t send live measurements. Instead, users scan their device to get current updates and readings stored on the sensor. Flash blood glucose monitoring is technically not CGM.

advantage

• Real-time tracking and trends. CGM provides real-time blood sugar data, letting users know if their blood sugar is rising or falling so they can make more informed decisions about diet, exercise, and medication .
• Alerts and Notifications. CGM sends alerts when blood sugar is too high or too low, allowing early intervention.
• Detailed information for doctors. The data can be read at the clinic and used to help monitor patients.
• No more bleeding fingers or carrying a kit around. This is life-changing for people living with diabetes.
• Many patients do finger prick testing infrequently, but CGM testing does not require extra effort and is reliable throughout the day.

problem

• price. This technology can be more expensive.
• Skin irritation and allergic reactions to the adhesive may occur.
• Delayed readings. CGM measures interstitial blood glucose approximately 15 minutes after blood glucose. If your blood sugar is changing rapidly, the readings may not be accurate. It is important that patients are aware of this to avoid incorrect insulin dosing decisions.

What devices are available?
Abbott offers freestyle libre The system uses a small sensor placed on the back of the upper arm and can be worn for up to 14 days.

The system provides glucose readings by scanning the sensor with a handheld reader or smartphone app. The first Libre was a flash glucose monitoring device, while the more recent Libre 2 and Libre 3 are full CGM devices.

Dexcom offers several CGM devices including: Dexcom G6 and Dexcom Onea standalone device that can be worn for up to 10 days and provides real-time glucose data via a smartphone app.

Both Abbot and Dexcom monitors can be prescribed under standard GP prescriptions.

Medtronic (Guardian Connect), Sensonics (Eversense and sugar beat). However, these are not available by prescription, not all are available in the UK and are usually prescribed in hospital clinics or purchased by patients.

NICE guidelines and prescribing timing
In 2022, NICE updated its guidelines to recommend flush or CGM for all adults with type 1 diabetes.

These new guidelines represent a shift towards a deeper understanding of technology as an integral part of diabetes management rather than as a luxury.

Nice NG17 In (Type 1 Diabetes in Adults: Diagnosis and Management), “For adults with type 1 diabetes, the choice between real-time monitoring (rtCGM) or intermittent scan monitoring (isCGM, commonly referred to as ‘flash’) is based on the patient’s symptoms. provide.” Personal preferences, needs, characteristics and available device capabilities.

For type 2 diabetes, NICE also recommends CGM, but only for adults who take multiple daily insulin injections and who:

• Recurrent or severe hypoglycemia.
• Cognitive impairment of hypoglycemia.
• Failure means inability to self-monitor.
• You should self-monitor yourself at least eight times a day.

How to prescribe and educate
For Libre and Dexcom One, the prescription is issued in the same way as for glucose test strips. CGM is usually initiated in secondary care, but monitoring can be initiated by a GP with sufficient expertise if local guidelines permit.

Please note that the patient needs a smartphone to receive the data. Most of the latest mobile phones are compatible. You have to download the app to use it.

Patients should be educated on device use.

Most patients learn to use it within an hour and find it much easier than a finger prick. Ensure patient education is appropriate and effective for all. Make sure the patient understands that the readings are 15 minutes behind her, and if the readings change rapidly, the fingerstick test should be used to confirm accurate readings. Leave a small amount of test strips on the refill prescription.

To provide education on how to use the device, you can:

• Familiarize yourself with how to use the device and show it to the patient during the examination.
  As a longtime user, I take this approach.
• Ensure that nurses on duty are product savvy and can guide patients through the process.
• Send the patient a link to the manufacturer’s instructional video.

Patients should also be taught how to use data from monitoring machines. This is best done by a secondary care clinic or a diabetes nurse.

Audit people with type 1 diabetes
Perform a clinic search for patients with type 1 diabetes. If you’re not at CGM, flag it for discussion at your next diabetes test, talk it over the phone, or encourage the diabetes team to take up the issue.

Dr. Shammy Nua is a Litchfield General Practitioner. staffordshire