What is the best approach to manage insulin pump therapy in a patient with type 1 or advanced type 2 diabetes mellitus (DM)?

Management of Insulin Pump Therapy

For patients with type 1 diabetes, insulin pump therapy (continuous subcutaneous insulin infusion, CSII) should be managed through a structured approach that includes proper patient selection, comprehensive education on carbohydrate counting and insulin dose adjustment, integration with continuous glucose monitoring, and consideration of automated insulin delivery systems for optimal glycemic control while minimizing hypoglycemia risk. 1

Patient Selection for Pump Therapy

Primary candidates for insulin pump therapy include:

• Patients with type 1 diabetes who have A1C ≥7% despite optimized multiple daily injections with appropriate basal-bolus dosing 2
• Those experiencing frequent or severe hypoglycemic episodes, particularly nocturnal hypoglycemia 1, 2
• Patients with pronounced dawn phenomenon requiring variable overnight basal rates 2, 3
• Highly motivated individuals who demonstrate proficiency in carbohydrate counting and correction dose calculations 2

For type 2 diabetes patients, insulin pumps can be considered for those on multiple daily injections who are clinically insulin deficient, as this may improve patient satisfaction and simplify therapy, though A1C reductions are not consistently superior to MDI 1

Essential Patient Education Requirements

Before initiating pump therapy, patients must demonstrate competency in:

• Carbohydrate counting with ability to match prandial insulin doses to carbohydrate intake 1
• Calculating correction doses based on premeal blood glucose levels 1
• Adjusting insulin for anticipated physical activity 1
• Frequent blood glucose monitoring or CGM use 2, 4
• Recognition and treatment of hypoglycemia 1
• Understanding "sick day rules" for managing hyperglycemia 1
• Technical pump management including reservoir filling, infusion set changes, and troubleshooting alarms 5, 6

Education programs should be structured and systematic rather than haphazard, as unstructured approaches have been associated with increased rates of severe hypoglycemia and ketoacidosis 7

Insulin Selection and Dosing Strategy

Use rapid-acting insulin analogs (lispro, aspart, or glulisine) in the pump reservoir, as these are preferred over regular human insulin for better postprandial glucose control 1, 5, 4

Basal rate programming:

• Establish multiple basal rate segments throughout the 24-hour period to match physiologic insulin needs 1, 6
• For dawn phenomenon, program a stepped-up basal rate starting 2-3 hours before the typical morning glucose rise, increasing infusion by 20-37% above standard basal rate 3
• Adjust basal rates based on overnight and fasting glucose patterns 1

Bolus dosing:

• Use the pump's built-in bolus calculator to determine insulin doses based on insulin-to-carbohydrate ratio (ICR) and correction factor 1
• Administer bolus insulin within 15 minutes before or immediately after meals 5
• For patients using automated insulin delivery systems, simplified meal announcement methods may be used as an alternative to precise carbohydrate counting 1

Integration with Continuous Glucose Monitoring

CGM should be integrated into pump therapy as standard of care for most patients with type 1 diabetes, as this improves glycemic outcomes, decreases hypoglycemic events, and improves quality of life 1, 6

Sensor-augmented pump therapy with threshold suspend feature reduces nocturnal hypoglycemia without increasing A1C values, and should be considered for patients with frequent nocturnal hypoglycemia or hypoglycemia unawareness 1

Automated insulin delivery (AID) systems are superior to sensor-augmented pump therapy alone, providing increased time in range and reduced hypoglycemia 1

Critical Safety Protocols

Infusion set management:

• Replace insulin in the reservoir at least every 7 days to avoid insulin degradation and loss of preservative 5
• Change infusion sets and insertion sites at least every 3 days 5
• Discard insulin exposed to temperatures higher than 98.6°F (37°C) 5
• Rotate infusion sites; report erythematous, pruritic, or thickened sites and select new locations 5

Preventing diabetic ketoacidosis (DKA):

• Patients must understand that pump malfunction, infusion set occlusion, leakage, disconnection, or kinking can lead to rapid hyperglycemia and ketosis due to the short duration of action of rapid-acting analogs 5, 6
• If hyperglycemia or ketosis cannot be promptly corrected, resume therapy with subcutaneous insulin injection immediately 5
• Check for pump alarms, infusion site problems, and insulin degradation when unexplained hyperglycemia occurs 1

Perioperative Management

During elective surgery, patients can safely remain on basal insulin infusion from their pump, as there is no evidence of detrimental effects and some evidence of more stable glucose control 1

• Continue hourly capillary blood glucose monitoring during surgery 1
• Do not use CGM sensors to track glucose values during surgery due to discrepancies between interstitial and capillary glucose caused by hemodynamic changes 1
• Postoperatively, continue hourly monitoring until the patient is fully conscious and capable of managing their pump 1
• Use the pump's bolus calculator for correction doses when blood glucose increases postoperatively 1

Inpatient Management

Patients competent to use their pumps should be allowed to continue pump therapy in the hospital when proper supervision is available, as they can often adjust insulin doses more knowledgeably than staff unfamiliar with their management style 1

This should occur based on hospital policies for diabetes management, with supervision to ensure appropriate insulin dose adjustments in the context of infection, medications, immobility, and dietary changes that can impact insulin sensitivity 1

Common Pitfalls to Avoid

• Never transfer HUMALOG U-200 from a pen to a syringe, as syringe markings will not measure the dose correctly, resulting in overdosage and severe hypoglycemia 5
• Do not mix HUMALOG U-200 with any other insulin 5
• Do not use HUMALOG U-200 in an external insulin pump; only U-100 formulations are appropriate for pump use 5
• Avoid initiating intensive insulin therapy without systematic patient training, as this has resulted in excessive increases in severe hypoglycemia and ketoacidosis rates 7
• Do not continue pump therapy if the patient cannot promptly identify and correct hyperglycemia or pump malfunctions; resume subcutaneous injections and contact healthcare professionals 5