What are the primary recommendations for a patient using an insulin pump to manage their diabetes?

Insulin Pump Therapy for Diabetes Management

Primary Recommendation

Insulin pump therapy should be considered as an option for all adults, children, and adolescents with type 1 diabetes who are capable of safely managing the device, particularly when HbA1c remains ≥7% despite optimized multiple daily injections, or when patients experience recurrent severe hypoglycemia or pronounced dawn phenomenon. 1, 2

Patient Selection Criteria

Ideal Candidates

• Patients with type 1 diabetes achieving inadequate glycemic control (HbA1c ≥7%) despite appropriate basal-bolus dosing with multiple daily injections 2
• Individuals experiencing frequent or severe hypoglycemic episodes, especially nocturnal hypoglycemia 2
• Patients with pronounced dawn phenomenon requiring variable basal insulin rates throughout the day 3, 4
• Highly motivated patients demonstrating proficiency in carbohydrate counting, correction dose calculations, and frequent glucose monitoring 2, 5

Essential Patient Capabilities

• Technical aptitude to manage pump programming and troubleshoot basic issues 2, 6
• Ability to perform self-monitoring of blood glucose every 2-4 hours during initiation and at least 4-6 times daily during maintenance 4, 5
• Understanding of the critical risk that pump disconnection or occlusion causes relative insulin deficiency within 1 hour and absolute deficiency within 4 hours, leading to severe hyperglycemia and ketoacidosis 1, 3, 2

Clinical Advantages Over Multiple Daily Injections

Insulin pump therapy provides a modest but clinically meaningful A1C improvement of approximately 0.30% compared to multiple daily injections 2, while offering:

• Precise basal insulin delivery with programmable hourly rates that can be instantly adjusted or suspended 3, 4
• Accurate bolus calculations using integrated calculators based on carbohydrate intake and correction factors 3
• Reduced rates of severe hypoglycemia compared to multiple daily injections 1
• Greater lifestyle flexibility for meal timing, exercise, and daily activities 3, 5
• Better fasting glycemic control due to stable, continuous insulin administration 3

Pump Programming Parameters

Initial Dosing Calculations

For metabolically stable patients with type 1 diabetes, start with 0.5 units/kg/day as the total daily dose (TDD), with approximately 50% programmed as basal delivery and 50% as bolus doses divided among meals 4

Basal Rate Programming

• Calculate total basal dose as 0.48 × TDD (approximately 40-60% of total daily insulin requirement) 4
• Program basal rates in different time blocks throughout the 24-hour period to account for the dawn phenomenon, with many patients requiring higher rates in early morning hours when counter-regulatory hormones are elevated 4
• Perform a basal test before surgery or when optimizing settings: blood glucose should not vary by more than 1.7 mmol/L (30 mg/dL) during fasting periods 1

Bolus Dosing Parameters

• Calculate insulin sensitivity factor (correction factor) as 1700/TDD for rapid-acting insulin analogs 4
• Determine carbohydrate-to-insulin ratio individually based on patient response and adjust every 3-6 months as physiological factors change 4

Special Population Adjustments

• Patients in honeymoon phase: 0.2-0.6 units/kg/day 4
• During puberty, pregnancy, or acute illness: >1.0 units/kg/day 4
• Elderly patients (>65 years) or high-risk individuals: 0.1-0.25 units/kg/day to prevent hypoglycemia 4

Insulin Selection and Supply

Use only rapid-acting insulin analogs (Novolog/Novorapid, Humalog, or Apidra) in insulin pumps—never use long-acting, intermediate-acting, or premixed insulins 3, 4

Practical Supply Considerations

• A 10mL vial contains 1000 units of U-100 insulin 4
• For a patient using 50 units/day, one vial provides 20 days of therapy 4
• Order 2-3 vials initially to ensure adequate supply during dose titration 4
• Tubed pumps require cartridges holding 180-300 units; patch pumps typically hold 200 units 4

Critical Safety Protocols

Glucose Monitoring Targets

Maintain blood glucose between 4-12 mmol/L (72-216 mg/dL), with optimal target range of 6-10 mmol/L (108-180 mg/dL) 3

Hypoglycemia Management

• If glucose falls below 4 mmol/L (72 mg/dL), treat immediately with oral glucose or IV dextrose if necessary 3
• Modern sensor-augmented pumps can automatically suspend insulin delivery when glucose is low or predicted to drop within 30 minutes 1, 3

Hyperglycemia and Ketosis Protocol

If blood glucose exceeds 14 mmol/L (252 mg/dL), immediately check the pump and infusion set for disconnection or occlusion, and perform a ketone test 3, 4

• If ketones are present, contact a diabetes specialist immediately 3
• This represents a medical emergency due to the risk of rapid progression to diabetic ketoacidosis 1, 2

Infusion Site Management

Patients must have insulin injection/infusion sites examined at least annually and whenever clinical issues related to insulin delivery arise 1

• Change disposable subcutaneous cannulas every 2-3 days to prevent site complications 3
• Rotate injection sites to prevent lipohypertrophy, which distorts insulin absorption 7

Monitoring During Initiation

Check blood glucose every 2-4 hours during the first 24-48 hours of pump therapy 4

Dose Adjustment Algorithm

• If hypoglycemia occurs: reduce basal rates by 10-20% 4
• If fasting glucose remains elevated: increase basal rates by 0.1-0.2 units/hour 4
• Reassess all pump settings every 3-7 days until glycemic targets are achieved 4
• Review and adjust all parameters every 3-6 months at specialized pump therapy clinics 4

Special Clinical Situations

Hospitalization

If the patient is fasting or requires IV insulin, start IV insulin at least 30 minutes before removing the pump, initially infusing at the basal rate per hour and adjusting according to glucose levels 3

• When returning to the pump, connect it and maintain the basal rate for at least 2 hours before suspending IV infusion 3
• Patients or parents/guardians should take responsibility for pump management during hospitalization, except during periods of reduced consciousness 1, 8

Surgical Procedures

For minor surgeries, insulin pump therapy can be continued with prior agreement and shared care between the patient and healthcare professionals 3

• For major or emergency surgeries, pump therapy is not appropriate and should be suspended, resorting to IV insulin according to local protocol 3
• Elective surgery should be delayed until optimal glycemic control is achieved with HbA1c <8.5% (69 mmol/mol) 1

Radiological Procedures

Remove the pump during CT/MRI or body X-rays 3

Automated Insulin Delivery Systems

Automated insulin delivery systems (closed-loop systems) may be considered in children and adults with type 1 diabetes to improve glycemic control 1

• Sensor-augmented pump therapy with automatic low glucose suspend may be considered to prevent/mitigate episodes of hypoglycemia 1
• Some patients use do-it-yourself closed loop systems not approved by the FDA; providers cannot prescribe these but should provide safety information and backup advice for individual devices to enhance patient safety 1

Continuity of Care

Individuals with diabetes who have been successfully using continuous subcutaneous insulin infusion should have continued access across third-party payers 1

• There is no evidence that C-peptide levels or antibody measurements predict success with insulin pump therapy 1
• Older adults with type 1 diabetes benefit from ongoing insulin pump therapy with no age-related contraindications 1

Common Pitfalls to Avoid

• Never dilute or mix rapid-acting insulin analogs with other insulins or solutions when loading pump reservoirs 4
• Never use premixed insulins in pump therapy 4
• Do not abruptly discontinue oral medications when starting insulin therapy in type 2 diabetes due to risk of rebound hyperglycemia 7
• Avoid intramuscular injections, especially with long-acting insulins during pump interruptions, as severe hypoglycemia may result 7
• Do not inject into areas of lipohypertrophy, which distort insulin absorption 7