Inpatient hyperglycemia

Initial steps

• Rule out DKA or HHS
• Identify and treat underlying cause (infection, medications, nutrition)
• Check HbA1c if not done in the last 3 months
• Adjust diet to consistent carbohydrate plan
• Hold oral agents:
  • Stop metformin and sulfonylureas
  • Hold SGLT2 inhibitors unless HF indication and patient is stable

Patients eating a normal diet

Type 1 DM (or insulin-treated Type 2 / new hyperglycemia)

• Continue outpatient insulin regimen if glucose well controlled
• Consider 25–50% dose reduction (intake usually more restricted inpatient)

Type 2 DM (not on insulin: diet, oral agents, or GLP-1)

• Continue outpatient regimen if glucose well controlled and no contraindications
• Be cautious with metformin and sulfonylureas
• If BG poorly controlled → discontinue outpatient regimen, start insulin

Basal insulin

• Continue home dose or start 0.2–0.3 units / kg / day
• NPH q12h, detemir q12–24h, or glargine q24h

+ Prandial insulin

• Continue home dose or start 0.05–0.1 units / kg / meal
• Insulin lispro, aspart, glulisine, or regular insulin

+ Correction insulin

• For BG ≥ 8.3 mmol/L (150 mg/dL)
• Graded scale 1–4 units per 2.8 mmol/L increment above target, based on insulin sensitivity
• Use same insulin type as prandial (add to it)

If BG remains uncontrolled

• Adjust basal insulin by 10–20% every 2–3 days
• Adjust prandial / correctional insulin by 1–2 units / dose every 1–2 days

Patients who are NPO or intake is uncertain

Type 1 DM (or insulin-treated Type 2 / new hyperglycemia)

• Basal insulin: continue home dose or start 0.2–0.3 units / kg / day
• NPH q12h, detemir q12–24h, or glargine q24h
• Correction insulin for BG > 8.3 mmol/L
• Graded scale: 1–4 units per 2.8 mmol/L increment
• Regular insulin q6h

Type 2 DM (not on insulin)

• Stop oral agents
• Start correction insulin for BG > 8.3 mmol/L (same graded scale, regular insulin q6h)

If BG remains uncontrolled

• Type 1 DM: adjust basal by 10–20% every 2–3 days, adjust correction scale as above
• Type 2 DM: add basal insulin (0.2–0.3 units / kg / day) and adjust as above
• If still uncontrolled → consider IV insulin infusion

Glycemic targets

• Non-critically ill: 5.5–10 mmol/L
• Critically ill: 7.8–10 mmol/L
• Accept ≤ 11 mmol/L in frail or terminally ill patients

Insulin regimens

• Non-critically ill
  • If eating: basal-bolus (basal + mealtime + correctional insulin)
  • If NPO / poor intake: basal + correctional insulin (no scheduled bolus)
  • Avoid sliding scale insulin alone (except short-term use)
• Critically ill
  • Continuous IV insulin infusion preferred
  • Transition to basal-bolus when stable
• Steroid-induced hyperglycemia
  • Basal-bolus regimen
  • If on prednisone / prednisolone: consider NPH-based regimen
  • If on dexamethasone: longer-acting basal

Monitoring

• NPO or continuous feeds: every 4–6 h
• Eating: before meals and at bedtime
• IV insulin: every 1–2 h
• BMP: every 1–2 days (renal function, electrolytes)
• Have hypoglycemia protocol ready (treat BG < 4 mmol/L)

Special situations

• Enteral / parenteral feeding: add regular insulin to PN bag or use scheduled basal + correctional
• Insulin pumps: continue if patient is capable and appropriate
• Seek endocrine consult if glucose remains difficult to control

Summary algorithm

1. Check BG
2. BG > 7.8 mmol/L = inpatient hyperglycemia → monitor, address cause
3. If ≥ 10 mmol/L persistently (two readings, ward or ICU) → initiate insulin
4. Choose regimen: basal-bolus if eating, basal + correctional if NPO
5. Target: 5.5–10 mmol/L (ward), 7.8–10 mmol/L (ICU)
6. Reassess daily and adjust

Related

Hyperglycemia on call (vital) · Inpatient medications