In this section, you will find descriptions of various devices used in the treatment of hyperglycemia, how each device works, and which patients might benefit from their use. The devices that have been developed for the treatment of hyperglycemia fall into two main categories: blood glucose monitoring and insulin administration. Patient education plays a key role in ensuring appropriate use of these devices.
Patient self-monitoring of blood glucose (SMBG) is usually done using a fingerstick capillary blood glucose meter, though blood samples may be taken from other areas of the body such as the palm of the hand or forearm.1 Blood glucose meter instructions should provide information for the availability of this option. There are several different blood glucose meters available in the US, each with varying accuracy.1 All meters measure glucose in a blood sample that is placed onto a test strip. Some meters utilize a chemical reaction and others measure electrical currents to quantify the glucose on the strip.2 Some glucose meters store blood glucose data to share with providers; newer meters may also have Bluetooth or wireless capabilities that allow data to be transferred and analyzed by an associated desktop, tablet, or smartphone app.
Real-time continuous glucose monitoring (CGM) measures interstitial glucose (glucose around the body’s cells), which correlates well with blood glucose levels.3 A small glucose sensor is placed subcutaneously and transmits continuous glucose measurements wirelessly to a wearable monitor.4 Sensors remain in place for up to a week and are then replaced. CGM devices are initially calibrated based on SMBG measurements. Integrated alarms indicate glucose excursions, defined as glucose levels that are higher or lower than the normal range, which are then verified by SMBG.4,5 The devices are still not approved by the US Food and Drug Administration as a sole agent to monitor glucose. CGMs require calibration with SMBG, with the latter still required for making acute treatment decisions.
CGM as an adjunct to SMBG may be useful for patients with type 1 diabetes on an intensive insulin regimen; children, teens, and young adults; and patients with hypoglycemia unawareness and/or frequent hypoglycemic episodes.3 CGM can help providers guide treatment adjustments and help patients increase their awareness of glucose excursions and how treatment and lifestyle changes help keep glucose levels within the target range.6 Because the success of CGM is related to adherence, individual patient readiness for CGM should be evaluated prior to use, and patients should undergo education, training, and support.3 Patients should understand the function of CGM, and learn how to calibrate the device based on SMBG, set the alarms, and transfer data from the device to a computer. Patients should also be able to respond appropriately in the event of a glucose excursion. They should also be capable of replacing the sensor. Fulfilling these few criteria means a patient may be ready to use CGM.
For patients receiving multiple daily injections (MDI) of insulin, insulin pens provide an alternative to vials and syringes. Insulin pen devices consist of an insulin cartridge or reservoir, to which the patient attaches a small pen needle, with no need to measure or draw up insulin from a vial. Both reusable and disposable insulin pen devices are available.7 Some find that insulin pens are easy to use, and dose adjustments are straightforward. For some pens, dosing adjustments are made with audible clicks to reduce the risk of over- or underdosing. Newer pens have recording features that can store data on frequency and dose of administration.6
Pens have several advantages over syringes and can help overcome patient fears of starting insulin.8 Certain patients find their ease of use also makes insulin administration less cumbersome for children and the elderly who may have limited motor skills or visual impairment that make insulin preparation and administration difficult. Most insurance companies now cover the cost of pen devices.8
As an alternative to MDI, continuous subcutaneous insulin infusion (CSII) is achieved with insulin pumps. These devices consist of a disposable plastic reservoir filled with insulin, which is delivered by a battery-powered mechanism through a subcutaneously implanted cannula into the abdomen.6 The device is programmed to dispense a continuous slow infusion of rapid-acting insulin analogs to mimic basal secretion and bolus injections prior to meals and snacks. CSII is reserved for patients with poor glycemic control or high variability of blood glucose despite optimized MDI, and for patients with type 1 diabetes who are experiencing severe hypoglycemia, frequent hypoglycemia unawareness, or nocturnal hypoglycemia.6 CSII requires extensive patient education and follow-up.
Sensor-augmented insulin pump therapy combines real-time CGM with CSII.6 These devices have a low glucose threshold suspend feature that terminates insulin infusion in the event that blood glucose levels are detected under a defined threshold level. Sensor-augmented insulin pump therapy is an option for patients with type 1 diabetes who have frequent nocturnal hypoglycemia and/or hypoglycemia unawareness.3