An insulin pump is a mechanical device that delivers insulin continuously from a reservoir in the pump to a subcutaneous site, usually in the abdomen, via a small cannula on a continuous basis.1-3 The process is referred to as continuous subcutaneous infusion of insulin (CSII). The cannula remains in situ, and is changed every two to three days to reduce the risk of infection or lipohypertrophy. The pump is battery powered, about the size of a pager and is portable, usually attached to the patient’s waist.
Insulin pumps are programmable, with the rate of insulin administered altered according to physiological need. A fast-acting insulin is contained within the pump reservoir and this is infused continuously with a basal rate which can be varied. Additionally, bolus doses are given to cover the carbohydrate load of meals and also to correct high blood glucose readings.
Carbohydrate counting is an essential skill to determine the bolus doses of insulin required at meal times.