measurements should be made 1–2 h after the beginning of the meal, generally peak levels in patients with diabetes.
TABLE 3. Plasma Blood Glucose and A1C Goals for Type 1 Diabetes by Age Group*
Discuss how critical it is for the patient to keep detailed records during the prepump education and pump start-up periods, which could last 1–4 months or longer. SMBG should include frequent pre- and postprandial blood glucose checks, at least four times a day, including one middle-of-the-night check around 3:00 a.m.
For enhanced pattern recognition purposes, ask the patient to also record factors that affect blood glucose, such as:
• Dietary intake, including grams of carbohydrate at each meal and snack
• Insulin doses (basal rates and bolus doses)
• Exercise: intensity, duration, and time of day
• Stress
• Illness
• Menstrual cycle
Patients who are already performing active self-management with MDI make the transition to pump therapy fairly easily. The challenges lie in what is common to both MDI and pump therapy—learning carb counting, planning ahead, adjusting doses for lifestyle issues, etc.
Patients Who Are Using Continuous Glucose Monitoring
CGM is another tool that may be helpful to you in determining your patient’s pattern of blood glucose control and deciding on initial pump basal rate(s) and bolus doses. Keep in mind the CGM measures glucose in interstitial fluid, not blood, so the values obtained at the same time from CGM and SMBG may not be identical. Refer to Chapter 6 for more on CGM.
Remind the patient of the learning curve associated with something as new and detailed as pump therapy initiation. Today’s “smart pumps” allow for easier determination of appropriate bolus doses and decision-making associated with pump therapy, but even the smartest of pumps cannot replace knowledge of the “hows” and “whys” of diabetes education and management. Make assurances that with time and experience, the patient will earn the freedom of being able to interpret his or her results and make safe self-management decisions using their insulin pump.
Carbohydrate Counting
It is essential that the patient, or parents if the patient is a child, learn and use advanced carbohydrate counting skills for several weeks or months before beginning pump therapy. It is both the prescribing clinician’s responsibility as well as the potential pump user’s responsibility that the prospective pumper has proficiency in advanced carbohydrate counting. Mastery of advanced carbohydrate counting skills requires instruction from an RD, preferably a CDE with pump therapy experience, and usually takes a few weeks to learn, depending on the patient’s history and abilities.
A person’s knowledge of carbohydrate counting and their comfort level with adjusting prandial (bolus insulin doses) will provide a foundation for success with insulin pump therapy. Many HCPs and prospective pumpers alike do not realize that this is the responsibility of the pump prescriber and pumper/parents. Teaching advanced carbohydrate counting skills is not the responsibility of a contracted per diem pump trainer or pump manufacturer employee (sales representative, territory manager, clinical education specialist, clinical manager, etc.) on the day of the pump therapy training or initiation. At this point, it is too late in the process to begin teaching carbohydrate-counting methods and concepts. Ideally, a prospective pumper should be able to demonstrate advanced carbohydrate-counting skills weeks or months BEFORE beginning pump therapy.
After initial review with the prospective pumper/parents, use follow-up session(s) as necessary to validate the patient’s/parents’ ability to count carbohydrate grams accurately. For additional information, refer to the American Diabetes Association book Practical Carbohydrate Counting: A How-to-Teach Guide for Health Professionals (Warshaw 2008). Although some pumps offer a carbohydrate gram database of commonly eaten foods, every pump patient should know how to accurately count carbohydrate grams of their favorite foods and be able to manually calculate a bolus insulin dose based on their specific insulin-to-carbohydrate ratio(s). Smartphones and thinkpads allow the downloading of a variety of useful carbohydrate applications that serve as a reference source for unfamiliar foods or restaurant meals. Some pumps offer the ability for the user to build a personalized food database of commonly eaten favorite foods and beverages and then program these as preset amounts with user-assigned names, such as “pancake breakfast” or “dinner salad.”
Another innovative pump option allows the user to simply input the meal items to be consumed; the pump adds the carbohydrate grams, and based on personalized information programmed by the user, calculates the appropriate carbohydrate bolus. Regardless of the manner in which a pump user totals his/her meal and snack carbohydrate amounts, it is essential that the user understand how to use an insulin-to-carbohydrate ratio(s).
Food labels provide the total carbohydrate grams, but if the patient is not accurate in knowing the carb amounts of the portions s/he is eating (i.e., adding up the total grams of carbohydrate in their meal or snack), the bolus insulin dose will not be correct. Stress the importance of accurate measurements and knowing how to use insulin-to-carbohydrate ratio(s) consistently.
There are countless stories of “pump therapy failures” or people whose pump therapy “just didn’t work right," etc. Many of these disheartening tales of failed pump therapy can easily be traced to lack of carbohydrate-counting skills coupled with inaccurate basal doses, or, worse yet, one constant hourly basal rate for 24 hours. There are even cases of people using an insulin pump with a set bolus dose per meal (often referred to as “a very expensive insulin pen or syringe”) without any regard to the amount of carbohydrate to be consumed. Again, it is essential that the patient or parents if the patient is a child, master carbohydrate counting before beginning pump therapy. It is a must for successful pump therapy.
For specifics on calculating insulin-to-carbohydrate ratios, see Calculating Insulin-to-Carbohydrate Ratios in Chapter 5.
Is the Patient Ready?
A prospective pump candidate should be adept at answering the following questions related to carbohydrate counting and insulin pump therapy without hesitation:
1. Do you know which foods contain carbohydrate?
2. How do you know how much carbohydrate you eat? (i.e., how do you count carbohydrate?)
3. How do you determine your premeal insulin doses?
4. What is (are) your insulin-to-carbohydrate ratio(s)?
5. Do you know how long your insulin (dose[s]) lasts?
6. How do you treat your high blood glucose levels?
7. What is (are) your correction (or insulin sensitivity) factor(s)?
8. How do you treat hypoglycemia?
Hyperglycemia
Remind the patient that the pump uses only rapid-acting insulin, and if there is an unexpected or accidental interruption of basal insulin delivery or an inaccurate or missed bolus, hyperglycemia can occur. Other causes of hyperglycemia during pump therapy
