Assess new insulin plan for MDI when discontinuing CSII
STEP 1 — Gather Information
Collect current CSII settings: basal rates across 24h, bolus insulin-to-carbohydrate ratios, correction/sensitivity factors, active insulin time, glucose targets. Review recent glucose monitoring data (SMBG/CGM), hypoglycemia episodes, HbA1c, patient carbohydrate counting ability, injection technique proficiency, and willingness to perform MDI. Document all collected data in the patient's transition worksheet.
STEP 2 — Rule In / Rule Out
Rule out if patient is unable or unwilling to perform multiple daily injections, lacks basic carbohydrate counting skills, or has uncontrolled hypoglycemia unawareness without adequate support. Rule in if patient demonstrates willingness, ability to self-administer injections, and has a reliable glucose monitoring plan. Proceed to classification if ruled in; otherwise, address barriers or consider alternative therapy.
STEP 3 — Classify or Stratify
Stratify by diabetes type: For type 1 diabetes, calculate total daily dose (TDD) from pump data; for type 2 diabetes, consider existing basal insulin needs and prandial requirements. Further classify by hypoglycemia risk: high risk if recent severe hypoglycemia or hypoglycemia unawareness. Assign patient to appropriate dosing strategy stratum.
STEP 4 — Decide
Decide on new MDI regimen: Set basal insulin (e.g., glargine, detemir, degludec) at 80% of TDD divided into once or twice daily; allocate remaining 20% for bolus insulin using meal-specific insulin-to-carbohydrate ratios and correction factors derived from pump settings. Provide written schedule and education on injection sites, storage, and back-up plan for missed doses. Prescribe the calculated MDI regimen and provide patient education.
Clinical Guardrails / Mimics / Pitfalls
Do not simply copy pump basal rates as MDI basal dose without adjustment; avoid ignoring carbohydrate counting ability leading to dosing errors; do not neglect to provide a clear sick-day plan and hypoglycemia treatment instructions; avoid assuming patient can manage complex multiple injection regimens without assessing dexterity and cognition.
Concrete Clinical Example
A 45-year-old with type 1 diabetes discontinues CSII due to recurrent infusion site infections. Pump data show TDD 48 U/day (basal 20 U, bolus 28 U). Carbohydrate ratio 1:10 g/U, correction factor 1:50 mg/dL/U, target 110 mg/dL. Transition to MDI: basal glargine 16 U nightly (80% of 20 U basal), bolus aspart with meals using 1:10 ratio and correction factor 1:50, plus glucose target 110 mg/dL. Provide education on injection rotation and back-up plan.
Source: Diabetes Technology—Continuous Subcutaneous Insulin Infusion Therapy and Continuous Glucose Monitoring in Adults: An Endocrine Society Clinical Practice Guideline, Endocrine Society, 2016, https://doi.org/10.1210/jc.2016-2534