Makindo Medical Notes

💉 Insulin pumps are small electronic devices that deliver continuous subcutaneous insulin. They provide basal insulin throughout the day and bolus doses at mealtimes, reducing the need for multiple daily injections. This helps stabilise glucose, lowers HbA1c, and reduces hypoglycaemia risk.

📍 Key Facts

• Most common in Type 1 diabetes; can be used in Type 2 but NHS funding is limited (cost: £2000–£3000).
• Requires a backup insulin kit in case of pump failure or disconnection.
• Pump site changed every 2–3 days; insulin delivered through a cannula under the skin.
• Needs frequent glucose checks (at least 4/day or CGM integration).
• Provides flexibility with meals and exercise, improving quality of life.

⚙️ Types of Insulin Pumps

• 🔗 Tethered Pumps:
  • Connected to the body via tubing (infusion set).
  • Pump carried in pocket, belt, or clothing.
• 📌 Patch Pumps:
  • Adhere directly to skin, no tubing.
  • Controlled wirelessly by handset or smartphone app.

🧩 Functions of Insulin Pumps

• Deliver continuous basal insulin (background rate).
• Provide bolus doses at mealtimes or to correct hyperglycaemia.
• Programmable profiles to match sleep, activity, or shift work patterns.
• Many integrate with continuous glucose monitors (CGMs) → “hybrid closed loop” systems (automated insulin adjustment).

📖 NICE Guidance – Pumps Recommended If:

• Frequent hypoglycaemia or hyperglycaemia despite best insulin therapy.
• HbA1c > 69 mmol/mol despite multiple daily injections and structured education.

✅ Benefits of Insulin Pumps

• Improved glycaemic control → ↓ HbA1c.
• Reduced severe hypoglycaemia episodes.
• Precise insulin dosing (basal/bolus tailored to patient).
• Greater lifestyle flexibility (meal timing, sports, travel).
• Integration with CGMs → real-time feedback and semi-automated dosing.

⚠️ Considerations

• Training & Education 🧑‍🏫: patients must be taught troubleshooting, carb counting, sick day rules.
• Cost 💷: NHS funding criteria strict; ongoing supplies also costly.
• Maintenance 🧽: site changes every 2–3 days to prevent infection/blockage.
• Technical issues ⚡: risk of pump failure → need for backup injections.
• Lifestyle 👟: pump must be considered for swimming, contact sports, sleeping positions.

🛠️ Set-up

• Main pump unit contains insulin reservoir (176–300 units).
• Reservoir connected to tubing (infusion set) → cannula under skin.
• Patch pumps deliver insulin directly via skin cannula without tubing.

📚 Teaching Pearls

• Pumps deliver only rapid-acting insulin (e.g., NovoRapid, Humalog) – no long-acting insulin is used.
• Ketoacidosis risk 🚨: if cannula blocks or pump fails, DKA develops quickly as no basal long-acting insulin is present.
• Closed-loop systems (“artificial pancreas”) are emerging → pump + CGM + algorithm.
• In exams: NICE criteria (HbA1c >69 or recurrent severe hypos) is key trigger for pump initiation.

🔗 References

• Diabetes UK – Insulin Pumps