An insulin pump is a small, computerized medical device worn externally that delivers rapid-acting insulin continuously into the body through a thin tube or a patch. This continuous subcutaneous insulin infusion (CSII) system provides a steady, background supply of insulin, known as basal delivery. It also allows the user to manually deliver extra doses, called boluses, around mealtimes or to correct high blood sugar levels. Patients who qualify for and benefit from this advanced therapy must meet both medical and behavioral criteria.
Primary Candidates: Type 1 Diabetes Patients
Individuals diagnosed with Type 1 Diabetes (T1D) represent the most common and intended user population for insulin pump therapy. This condition involves the near-total destruction of pancreatic beta cells, resulting in an absolute deficiency of insulin production. Because the body cannot produce any background insulin, the pump’s ability to deliver minute, continuous basal doses is highly advantageous for maintaining stable glucose levels between meals and overnight.
A strong indication for a pump is a history of persistent, unstable blood glucose control despite a commitment to an optimized multiple daily injection (MDI) regimen. This instability often includes wide, unpredictable swings in glucose levels, known as high glycemic variability. Furthermore, patients who experience frequent or severe episodes of low blood sugar, particularly those with hypoglycemia unawareness, can find the pump beneficial because it allows for immediate, temporary reduction or suspension of basal insulin delivery.
Pump therapy is frequently initiated in children and adolescents who have T1D, even infants and toddlers. This is due to the pump’s capability to deliver extremely small, precise doses of insulin that are necessary for the low insulin requirements of young children. For adolescents, who often experience hormonal fluctuations and rapid changes in activity levels, the pump offers the flexibility required to manage these dynamic metabolic needs effectively. The technology significantly helps in mitigating phenomena like the “dawn phenomenon,” where blood sugar spikes early in the morning due to hormonal surges.
Secondary Candidates: Type 2 Diabetes Patients
While less common, individuals with Type 2 Diabetes (T2D) may also be considered candidates for pump therapy when specific management challenges exist. This option is reserved for T2D patients who have complex insulin needs and have failed to achieve adequate glucose control using other intensive insulin regimens. A patient may be considered if they have severe insulin resistance leading to high daily insulin requirements that are difficult to manage with injections.
Pump use may also be appropriate for T2D patients who continue to experience elevated glucose levels, even after maximizing oral medications and multiple daily injections. Additionally, the pump’s ability to deliver a precise, extended bolus is helpful for individuals with gastroparesis, a complication where the stomach empties slowly, making mealtime insulin dosing challenging. A formal trial of an optimized MDI regimen lasting three to six months is required before a pump is approved for a T2D patient.
Essential Requirements Beyond Diagnosis
Successfully using an insulin pump requires a high level of patient engagement and technical proficiency. The patient must be committed to the intensive self-management regimen that accompanies the device. This includes performing frequent blood glucose checks, or consistently using a continuous glucose monitor (CGM), to inform pump settings and dosing decisions.
A foundational requirement is the ability to accurately count carbohydrates for every meal and snack, as this information is manually entered into the pump’s bolus calculator. Patients must attend and complete intensive training programs to learn how to operate the device, calculate appropriate doses, and troubleshoot technical issues. Successful use also depends on having the necessary manual dexterity and cognitive ability to reliably manage the device, including changing the infusion set every two to three days.
When Pump Therapy is Not Appropriate
Insulin pump therapy is not a suitable option for every patient, as certain conditions can compromise its safe and effective use. A primary exclusion factor is a lack of motivation or unwillingness to comply with the self-care and monitoring requirements of the therapy. The high-risk nature of relying solely on rapid-acting insulin means that non-adherence can quickly lead to severe hyperglycemia or diabetic ketoacidosis.
Patients with severe cognitive impairment, significant visual limitations, or certain debilitating psychological conditions may be unable to safely and reliably operate the device and manage its alarms. Furthermore, a history of poor self-care or repeated failure to follow previous treatment protocols often disqualifies an individual due to the increased safety risk the pump would introduce. In situations like acute illness, severe infection, or diabetic ketoacidosis, pump therapy is temporarily paused and replaced with intravenous insulin delivery for closer medical supervision.