September 1, 2021
Continuous subcutaneous insulin infusion (CSII) through pump provide an alternative means of delivering insulin. It is the most physiological method of delivering insulin. It provide continuous subcutaneous delivery of short-acting insulin infusion (Lispro or Aspart) all day long and replaces the need of multiple daily injections in diabetics, especially type-1 diabetic patients. Preferred n patients uncontrolled on multiple injections and those needing excellent control such as in pregnancy, specially suitable for patient with risk of hypoglycemia, uncertain lifestyle and mealtimes.
Insulin pumps are small, the size of a smart phone, computerized devices that mimic the way a human pancreas work. Many pumps connect wirelessly with glucometer devices. Some can connect with continuous glucose monitoring devices.
The first insulin pump was created in 1974. It was so large that it was worn as a backpack. Today they are so small that they can be kept in a pocket. New insulin pumps have many added features. When it is integrated with continuous glucose monitoring device, (closed loop insulin therapy), it works like an artificial pancreas. It senses basal insulin requirements and automatically adjusts the insulin delivery. Continuous glucose monitoring systems suspend insulin delivery if the glucose level reaches a threshold.
Insulin pumps deliver insulin in two ways. Basal rates and a bolus dose.
Basal rate is a programmed small amount of continuous insulin delivery set up by the doctor depending on the need of the user. There can be more than one programmed basal setting. Basal requirements can be influenced by the factors such as illnesses, puberty, medication such as glucocorticoids, and exercise.
Bolus dose can be delivered on demand to match the food or to correct high blood sugar. Most pumps comes with bolus insulin calculator that help to calculate bolus dose depending on glucose reading and carbohydrate counting.
Types of pumps
A variety of pumps are available. In general there are two types of pump devices.
Traditional insulin pump
Traditional pumps are battery operated (2 AA alkaline batteries) small computerized device. It include a reservoir for insulin, pumping mechanism, and an infusion set. Tube length varies depending on where you want to wear the pump. Reservoir can hold 300 units of insulin and is changed every 2 or 3 days along with the infusion set. The pump is worn with a belt around the waist. It delivers insulin by an infusion set attached with a cannula. There are variety of accessories available, so you can carry pump with the style. Pump infusion rate is adjusted to maintain glucose in normal range. The pump body contains control buttons or has a touch screen.
Insulin patch pumps or Omnipods
It includes a reservoir and infusion set in a small case without tubing and it is waterproof. Device is worn on the body with self-adhesive tape. Patch pumps are controlled wirelessly by a separate device that allows programming of insulin delivery from the patch. Patch pumps are usually replaced every three days.
Features of insulin pumps may include, rechargeable batteries, remote control, dual hormone insulin pumps (that can inject glucagon too), programmable bolus, reminders, alert for missed bolus dose or missed glucose measurements, and alarm in the event of blockage.
Benefits of insulin pumps
- Fewer needles pricks
- Better glucose control and Improve HbA1c scores. Substantially reduce the variability of glucose levels.
- Fewer hypoglycemic events, especially overnight.
- Insulin pumps provide more flexibility with bolus injection in both timing and shape and also in changing basal rates. Pumps can be preprogrammed to compensate for nocturnal and early morning glucose fluctuations. Pumps can be discontinued for short period of activities like exercise or a temporary basal rate option can be set to reduce or increase basal rate during exercise or illnesses.
- Dose calculation: pumps can connect wirelessly to a glucometers which send reading to the bolus calculator. Built-in bolus wizard feature calculate the insulin requirement with current glucose level, carbohydrate intake, and personal insulin setting.
- Weight control and better quality of life.
- Far more costly than insulin pens and syringes
- Frequent and meticulous self-monitoring and close attention to pump function are necessary for safe and effective use of insulin pump. Only motivated and committed people can use it.
- pump failure, Pumps can malfunction, sometimes especially if the batteries are discharged or reservoir runs out causing interruption in insulin supply.
- There can be a kink in tubing, bubbles, or leaks.
- Inconvenience, as you have to wear it all the times.
- Skin problems can occur at site of infusion, such as injection site abcess