How does the insulin pump work?

An insulin pump is approximately the size of a pager.  It has a compartment to hold a small container of short acting insulin (usually Humalog).  There is tubing that connects the insulin to the catheter that is attached to the patient.  The patient changes the catheter every two days.  Leaving it in for longer may cause higher risk of infection and poor insulin absorption form the site - leading to higher blood sugar levels.  The catheter is soft and flexible.   A needle is required to help insert the catheter, but the needle is removed after insertion. There are devices that can help the patient and family insert the catheter.  Most people feel that the insertion is similar to an injection of insulin.

Basal (background) insulin doses are set to provide a continuous low-dose insulin infusion based on individual needs.  Some patients need higher basal rates early in the morning (3-8am) and decreased basal rates in the afternoon.  When a patient is going to eat a snack or a meal, they check their blood sugar and determine how much additional insulin to give through the pump (called a bolus) based on the blood sugar and the amount of carbohydrate about to be eaten.

What can the pump do?

1. Improve glucose control by allowing the patient to have normal pre-meal blood sugars without the use of long-acting insulin

In people who do not have diabetes, the pancreas is continuously making low levels of insulin.  It then gives bursts of insulin whenever it detects elevations of blood sugar levels (usually from food, but also from hormones).  The insulin pump helps mimic how our body provides insulin by providing a combination of continuous low-dose insulin (the basal rate) and extra doses of insulin to cover the meal-related increase in blood sugar. Importantly, the patient still needs to check the blood sugar and "tell" the pump what to do.  The benefits of the pump include flexibility because it is constantly providing background (basal) insulin.  So, blood sugars don't go up when the long acting insulin stops working. This gives people flexibility.

2. Improve flexibility in timing and amounts of meals

When using a pump, patients can choose when to eat rather than eating when a long-acting insulin is peaking or, risk high blood sugars because injected insulin is no longer working. Patients using a pump do not have to draw up insulin in a syringe or use a pen when injecting insulin.  They merely "press the button" on the pump and administer the insulin through the pump.

3. Improve flexibility in timing and amount of exercise

The pump allows for greater flexibility in exercise.  Without the use of long-acting insulin, hypoglycemia is less of a problem.  The insulin pump can also be "turned off" or even disconnected during exercise.

4. Reduce hypoglycemia (low blood sugars) in some patients

Many patients experience hypoglycemia related to unpredictable absorption and peaking of long and intermediate-acting insulins.  The pump uses only very short acting insulin and therefore patients do not have to calculate and react to peaks and valleys of insulin action.  This leads to decreased episodes of low blood sugar in many patients, especially overnight.

What can't the pump do?

It's important to recognize what the pump can and cannot do. Patients may be able to obtain good glucose control from insulin injections or from an insulin pump. The pump cannot automatically give patients excellent diabetes control without effort from the patient and family.  Patients still need to monitor their blood sugars and count carbohydrates.

Why do you want a pump?

When patients ask the pediatric team at Naomi Berrie about starting on pump therapy (CSII - Continuous Subcutaneous Insulin Infusion),  we ask them why they want a pump.  We get a lot of different answers:

  "All the kids in camp have one"
  "I don't want to give myself shots anymore"
  "I like the cool colors"
  "I want good control"
  "I want flexibility"

Many people believe that using an insulin pump is an easy and mindless way to obtain optimal blood sugar control.  We wish it was that easy.  The reality is that most of our patients find that CSII  requires as much attention as traditional multiple daily injections, even more in the beginning.  We expect that patients interested in CSII are currently approaching their diabetes management in an intensive manner.  This means that the patient should be monitoring their blood sugar 4-6 times a day.  Good pump candidates should also be adjusting their insulin doses related to carbohydrate intake and/or activity and then evaluating the effectiveness of those adjustments.  This approach to diabetes management is beneficial for all patients, even those not considering pump therapy.

What are your goals for pump therapy?

In our initial "assessment of readiness for the pump", our team likes to find out what the patient's goals for pump therapy are.  Some people are interested in pump therapy because of the flexibility it allows.  Others feel that physiologically the pump is a safer more predictable method of insulin delivery.  Whatever a person or family's goals may be, we at Naomi Berrie feel that addressing these goals and expectations for pump therapy is an important step in the transition from multiple injections to pump therapy.

What's the procedure for getting a pump at the Naomi Berrie Diabetes Center?

Before beginning insulin pump therapy the child and family are carefully evaluated by the team at the Center.  Our team includes a doctor, nurse-educator, dietician, and social worker who work closely with the patient and family to ensure that they are both educated and emotionally ready to begin using an insulin pump.  Among other issues, the diabetes education procedure ensures that prior to going on the pump, patients and their families know how to count carbohydrates.

Why must you count carbohydrates to use an insulin pump?

To be successful with the insulin pump. it is very important to understand how much insulin you need to "cover" all the foods that you eat.  In order to do this, you must know how much carbohydrate, the main nutrient in food that affects blood sugar, is contained in the foods you eat.
Carbohydrates are found in foods such as bread, cereal, rice, pasta, potatoes, fruit, and milk.  The carbohydrates in food are measured in grams.  You can find out how many grams are in the foods you eat by reading food labels, weighing foods with a scale, or measuring foods with measuring cups and spoons.  It is also helpful to get a carbohydrate counting book that lists foods and their carbohydrate content. You will need to take a specific amount of insulin for the amount of carbohydrate grams that you eat throughout the day.  This is called an insulin bolus.  Each person requires a different amount of insulin for the carbohydrates they consume.  You will need to keep detailed records of your food intake, carbohydrate grams, insulin doses and blood glucose levels for several weeks before starting the pump. Keeping records will help you learn how to count carbohydrates and it will help to determine how much insulin you need per gram of carbohydrate.  This is referred to as your insulin to carbohydrate ratio (e.g. 1 unit of insulin for 15 grams of carbohydrate = 1:15).

Are you ready for the pump?

During the assessment, our team first determines if the child/family feels ready to go on the pump.  The child and family must be highly motivated and responsible. In order to ensure success the child and parents should have strong support from the family and school system.  Our team often makes school visits to educate school nurses, teachers and classmates about diabetes and the insulin pump.

The child must consider how he or she feels about being "hooked up" to an insulin pump at all times.  For some children, being attached to a device is no problem, however, other kids find it strange and are not comfortable with the idea at first. Our pediatric team is in the process of formulating a self-assessment questionnaire that will assess the psychological effects of wearing an insulin pump.  These feelings are considered and discussed when evaluating if the pump is right for each patient.

The diabetes team works very closely with the pumper and his/her family to carefully manage the child's diabetes and provide on-going education and emotional support.  As you are in the process of becoming a pumping family, we recommend that you speak to as many people as possible.  Our Center hosts a monthly support group for pumpers and parents, which provides an opportunity to ask questions, learn new things, address issues and concerns, and most importantly to meet other pumpers and have fun!