What are the recommendations for using the Twiist AID (Automated Insulin Delivery) system with a tube for continuous insulin infusion?

Twiist AID System with Tubed Infusion Set: Key Recommendations

The Twiist AID system with tubed infusion sets requires the same critical attention to infusion site management as all tubed pump systems, with infusion set changes every 48-72 hours being essential to prevent the "Achilles heel" of insulin delivery interruption that can compromise automated insulin delivery performance. 1

Critical Infusion Set Management

Change Frequency

• Change infusion sets every 48-72 hours to minimize infusion site adverse events and prevent metabolic deterioration 1, 2
• This timeframe is patient-dependent and should be adjusted based on individual response, but extending beyond 72 hours significantly increases complication risk 2
• The tubed infusion set remains the most vulnerable component of any AID system, capable of silent occlusion or complete blockage without warning 1

Site Rotation Protocol

• Rotate infusion sites at least 1 cm (half an inch) away from the previous insertion point 1
• Preferred anatomical sites include: abdomen, upper third anterior lateral thighs, posterior lateral upper buttocks and flanks, and middle third posterior upper arm 2
• Check infusion sites at least annually by a healthcare provider for lipohypertrophy, nodules, scarring, or inflammation 1, 2

Troubleshooting Unexplained Hyperglycemia

Infusion Set Failure Detection

• Always suspect infusion set occlusion or failure when experiencing unexplained hyperglycemia or glucose variability 1
• Without automated algorithms for site failure detection, manual problem-solving is essential—assume insulin flow interruption until proven otherwise 1
• If lipohypertrophy is detected, immediately stop infusing into affected areas and insert the catheter into healthy tissue 1, 2

System Reversion Awareness

• Understand when your Twiist system automatically reverts to manual mode (preprogrammed basal rates) 1
• Missing CGM data or loss of connectivity triggers reversion to manual settings, which may not reflect current insulin requirements 1
• Update manual mode settings (basal rates, correction factors) periodically even while using AID, as overall insulin needs change over time 1

Essential User Competencies

Technical Requirements

• You must be capable of troubleshooting infusion set issues, recognizing when to revert to manual insulin delivery, and understanding all system limitations 1
• Maintain backup supplies including extra infusion sets, insulin, and alternative insulin delivery methods (pens or syringes) 1
• Ensure ability to independently problem-solve hyperglycemia by checking for failed infusion sets or broken system components 1

Behavioral Expectations

• Continue manual bolusing for meals—current AID systems are hybrid systems requiring user input for prandial insulin 1
• Avoid "stacking" correction boluses; the system should account for insulin-on-board automatically 3
• Do not add "fake carbs" to manipulate the system or overcorrect hyperglycemia 1

Settings Optimization

When to Adjust Parameters

• Recalculate correction factor using 1500/TDD or 1700/TDD formula every 3-6 months or when significant changes in weight, activity, or insulin requirements occur 3
• If correction doses consistently fail to bring glucose into target range, adjust the correction factor rather than basal insulin 3
• Monitor whether automated corrections are bringing glucose to target 2-4 hours post-correction 3

Basal Rate Adjustments

• Approximately 40-60% of total daily dose should be basal delivery, with remainder as mealtime and correction boluses 3
• Titrate basal insulin to achieve acceptable fasting glucose before adjusting other parameters 4
• Make only one setting change at a time to determine effectiveness 4

Special Situations Requiring Manual Mode

When to Disable AID

• During acute illness with ketosis (even without elevated glucose), as resolution requires increased insulin delivery that AID may not provide rapidly enough 1
• When starting systemic steroids, as AID systems may not respond quickly enough to dramatically increased insulin requirements 1
• During pregnancy, as lower glycemic targets may not be achievable with standard AID settings 1

Environmental Considerations

• Be aware that exposure to high or low temperatures, magnetic fields, or water can impact system function 1
• Understand how physical activity affects insulin requirements, as current AID systems may not optimally handle exercise-related needs 1

Data Management and Support

Healthcare Provider Access

• Ensure your healthcare provider has easy remote access to your AID system data 1
• Understand whether you need to manually upload data or if it transmits automatically 1
• Establish clear follow-up protocols for dose optimization, particularly during early use 1

Common Pitfalls to Avoid

• Never share insulin cartridges or pens between patients due to blood-borne disease transmission risk 1
• Do not ignore unexplained glucose variability—always investigate for infusion site issues 1, 2
• Avoid making multiple setting changes simultaneously, as this prevents identifying which change was effective 4
• Do not rely solely on AID without understanding how to revert to manual pump therapy or injections 1