Assess CGM alarm settings
STEP 1 — Gather Information
Collect recent CGM metrics (time <70 mg/dL, >180 mg/dL), current low/high alarm thresholds, frequency of alarm notifications, hypoglycemia unawareness, severe hypoglycemia history, and patient-reported alarm fatigue. → If data missing, obtain CGM download; otherwise proceed.
STEP 2 — Rule In / Rule Out
Is the patient experiencing hypoglycemia unawareness, recent severe hypoglycemia, or frequent low-glucose alarms disrupting sleep/activities? If yes, prioritize low alarm evaluation; if no, proceed to evaluate high alarm settings.
STEP 3 — Classify or Stratify
Classify alarm adequacy: low alarm too low (<60 mg/dL) causing fatigue, too high (>80 mg/dL) risking missed hypoglycemia; high alarm too low (<140 mg/dL) causing excessive alerts, too high (>250 mg/dL) missing hyperglycemia; or appropriately set.
STEP 4 — Decide
Adjust low alarm to 70–80 mg/dL if hypoglycemia unawareness or frequent low alerts; set high alarm 180–250 mg/dL or disable if consistently high without benefit; provide education on alarm response and SMBG confirmation.
Clinical Guardrails / Mimics / Pitfalls
Do not set low alarms above 80 mg/dL in hypoglycemia-unaware patients; avoid high alarms below 140 mg/dL causing alert fatigue; never replace symptomatic hypoglycemia verification with CGM alarms alone.
Concrete Clinical Example
A 45‑year‑old with T1D and hypoglycemia unawareness reports 4 nightly low alerts. Review shows low alarm at 55 mg/dL, high at 200 mg/dL. Low alarm raised to 70 mg/dL, high kept at 200 mg/dL; alerts drop to 1/night, sleep improves, no missed hypoglycemia.
Source: Diabetes Technology—Continuous Subcutaneous Insulin Infusion Therapy and Continuous Glucose Monitoring in Adults, Endocrine Society, 2016, DOI:10.1210/jc.2016-2534