Insulin pump therapy is the common name for the technique of continuous subcutaneous insulin infusion (CSII). Insulin pumps contain a chamber filled with insulin, connected to a small battery operated pump device which is controlled by a microprocessor (computer chip). The entire assembly is housed within a small case the size of a pager device (slightly larger than a pack of cigarettes). The user is able to control the amount of insulin released by the device which injects a tiny amount every minute into the subcutaneous tissue via a length of plastic tubing with a needle or soft cannula at the end.
The pump operates continuously, delivering insulin via the needle, 24 hours of the day.
The needle or cannula is inserted just under the skin of the abdomen. One needs to have the infusion set changed every two or three days.
Once inserted the cannula should not cause any pain.
At meal times, you simply programme the pump to deliver a ‘bolus dose’ of insulin to deal with the amount of food you have eaten. It is important to realise that the pump does not perform this automatically! You have to decide on the amount of insulin that should be given.
The pump may be worn in your clothing, placed under your pillow or on a bedside table. The length of tubing is usually adequate for the latter.
The pump should not be immersed. It may be disconnected from the tubing during a bath or worn in a special plastic bag while showering.
In general people with type 1 diabetes are suitable for pump therapy if they
Various manufacturers produce insulin pumps. Some of the products available include
Many of the new insulin pumps use rapid acting insulin analogues NovorapidR and HumalogR.
Funding on the NHS is currently not available for pump therapy. Diabetes UK has recently submitted a proposal to the Department of Health in June 2001, asking for insulin pump therapy to be appraised by the National Institute for Clinical Excellence (NICE). NICE is part of the NHS and undertakes appraisals of medical technologies. It produces guidance for both the NHS and patients on medicines, medical equipment and clinical procedures based on evidence of clinical and cost effectiveness.
If used properly, may improve blood sugar control. Reduction in rates of hypoglycaemia demonstrated. Severe hypoglycaemia requiring outside assistance is estimated to be 20-33% less frequent in pump users. Improved well being and quality of life reported.
The pumps cost over £2,000 each; running costs are estimated at around £1,000 each year.
DiabetesUK estimates that approximately one fifth of one per cent of people with Type 1 diabetes in the UK use pumps (that is one I five hundred people with type 1 diabetes). The total numbers across the UK are likely to be under one thousand. This compares with about eight per cent in the United States, 12 per cent in Sweden, and 10 per cent in Germany1.
If you are keen to start on insulin pump therapy discuss this with your diabetes nurse specialist or when you visit the diabetes clinic. If you are suited for pump therapy you would need to undergo training in carbohydrate counting and pump use.
The National Support Group for Pump Users, INPUT, supporting insulin pump therapy, can provide more information about pump therapy and usage. INPUT is a patient led support group for diabetics using insulin pumps, run by pump users and their families.
The National Institute of Clinical Excellence (NICE) has recently published guidelines on pump therapy – website: www.nice.org.uk.
Dr Nishan Wijenaike, Consultant Physician
West Suffolk Diabetes Service