endo-preoperative-bg-target-if-hba1c-not-feasible

name	endo-preoperative-bg-target-if-hba1c-not-feasible
description	Suggests targeting preoperative blood glucose concentrations of 100–180 mg/dL when achieving HbA1c <8% is not feasible prior to elective surgery. Use when a clinician faces upcoming surgery with insufficient time to lower HbA1c below 8%.

Target preoperative blood glucose 100–180 mg/dL if HbA1c goal unattainable before surgery

STEP 1 — Gather Information

Collect HbA1c, estimated time to surgery, current BG, diabetes type, insulin regimen, total daily dose, hypoglycemia history, renal function, and factors affecting HbA1c (anemia, hemoglobinopathies, chronic renal failure, alcoholism, drugs).
Decision: Proceed to assess feasibility of HbA1c <8% target.

STEP 2 — Rule In / Rule Out

Determine if HbA1c <8% can be achieved before surgery given available time and interventions.

• If yes, pursue HbA1c <8% target (standard preoperative goal).
• If no, proceed to target preoperative BG 100–180 mg/dL.
  Decision: Target preoperative BG 100–180 mg/dL.

STEP 3 — Classify or Stratify

Assess suitability for DPP4i: recent HbA1c <7.5%, BG <180 mg/dL, and if on insulin, total daily dose <0.6 units/kg/day.

• If all met, classify as select candidate for DPP4i.
• If any not met, classify as non‑select.
  Decision: Classify patient for therapy selection.

STEP 4 — Decide

• If select candidate, consider initiating DPP4i with correction insulin or scheduled insulin therapy to maintain BG 100–180 mg/dL.
• If non‑select, initiate scheduled insulin therapy (basal‑bolus or basal plus correction) to maintain BG 100–180 mg/dL.
  Decision: Implement glucose‑lowering regimen to achieve preoperative BG 100–180 mg/dL.

Clinical Guardrails / Mimics / Pitfalls

Do not apply to patients with type 1 diabetes or other insulin‑dependent diabetes. Account for conditions that alter HbA1c (anemia, hemoglobinopathies, chronic renal failure, alcoholism, drugs, large BG variations). Ensure adequate time to implement therapy before surgery. Avoid DPP4i in patients outside select criteria (HbA1c ≥7.5%, BG ≥180 mg/dL, insulin dose ≥0.6 units/kg/day). If BG remains >180 mg/dL on DPP4i, transition to scheduled insulin therapy. Do not rely solely on correctional insulin for persistent hyperglycemia.

Concrete Clinical Example

A 60‑year‑old woman with type 2 diabetes scheduled for elective cholecystectomy in 7 days has HbA1c 8.2% and cannot achieve <8% due to limited time. She takes metformin only, average BG 160 mg/dL, and does not meet select criteria for DPP4i. She is started on basal insulin (glargine 0.3 units/kg) with correctional insulin as needed to keep preoperative BG between 100–180 mg/dL.

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

TODO: consider adding scripts/calc.py for the endo-preoperative-bg-target-if-hba1c-not-feasible calculator