Revert insulin pump to manual mode if CGM fails or is removed

STEP 1 — Gather Information

• Confirm CGM failure or removal (sensor error, dislodgement, patient report).
• Assess patient ability to self-manage pump (alert, competent, no impaired consciousness).
• Verify absence of contraindications to pump use: not in ICU, no DKA/HHS, no severe hypoglycemia unawareness.
• Ensure pump supplies (infusion sets, reservoirs, insulin) are available for duration of hospitalization.
• Check hospital policies and availability of expertise for pump management.

STEP 2 — Rule In / Rule Out

• Is CGM failed or removed?
  • Yes → proceed to Step 3.
  • No → continue pump with CGM-guided automation and routine POC-BG confirmation.

STEP 3 — Classify or Stratify

• Are basic criteria for pump use in hospital still met?
  • Yes → proceed to Step 4 (revert to manual mode).
  • No → transition to scheduled subcutaneous basal bolus insulin therapy (see Table 3 for conversion).

STEP 4 — Decide

• If criteria met: switch pump to manual mode (disable automated features, use pre-set basal rates and manual bolus calculations).
• Order frequent POC-BG monitoring (e.g., every 4–6 hours or per institutional protocol) to guide manual dosing.
• Document mode change and notify nursing/pharmacy.

Clinical Guardrails / Mimics / Pitfalls

• Do not revert to manual mode if patient cannot safely adjust pump settings (e.g., altered mental status, delirium).
• Avoid manual mode in patients with active DKA, HHS, or requiring vasopressors; transition to IV insulin instead.
• Ensure backup glucose monitoring is in place; reliance on CGM alone is unsafe after failure.
• Do not assume pump function is intact; verify infusion set integrity and insulin potency.
• Pitfall: continuing automated pump modes with erroneous CGM data can cause hypoglycemia or hyperglycemia.

Concrete Clinical Example

A 62-year-old woman with type 1 diabetes on hybrid closed-loop pump admitted for cholecystectomy. On postoperative day 1, her CGM displays persistent "sensor error" alerts. She is alert, able to troubleshoot pump, has spare supplies, and no ICU stay. The team confirms CGM failure, verifies she meets pump-use criteria, reverts the pump to manual mode, and orders POC-BG checks every 6 hours.

Source: Management of Hyperglycemia in Hospitalized Adult Patients in Non-Critical Care Settings: An Endocrine Society Clinical Practice Guideline, Endocrine Society, 2022, https://doi.org/10.1210/clinem/dgac278