Hospital diabetes management is a structured approach to glucose control during admission — targeting 140 to 180 mg/dL for most patients, using basal-bolus subcutaneous insulin or IV insulin infusion rather than sliding scale alone, and starting discharge planning on day one. Done well, it reduces wound infections, length of stay, readmissions, and mortality. Done poorly, it produces preventable hypoglycemia, DKA, and discharge medication errors.
Why Inpatient Glycemic Control Matters
- Hyperglycemia (over 180 mg/dL) is associated with longer hospital stays, more infections, and higher mortality across nearly every condition
- Hypoglycemia (under 70 mg/dL) also increases mortality and cardiovascular events
- The relationship is U-shaped — both extremes are harmful
- Stress hyperglycemia in patients without known diabetes carries similar prognostic weight
- About 30 percent of hospitalized patients with hyperglycemia have undiagnosed diabetes — A1C during admission identifies them
ADA Inpatient Glycemic Targets (Section 16)
| Setting | Target Range (mg/dL) |
|---|---|
| Most non-critically ill | 140–180 |
| Critically ill (ICU) | 140–180 (110–140 for selected patients) |
| Post-cardiac surgery | 110–140 typical |
| Pregnancy in hospital | Tighter — fasting under 95, post-meal under 140 |
| End-of-life / palliative | Liberal — symptom-based |
| Hypoglycemia threshold | Below 70 (severe under 54) |
| Hyperglycemia threshold | Above 180 (sustained above 250 — escalate care) |
Inpatient Insulin Strategies
| Patient Status | Preferred Regimen |
|---|---|
| Eating, not critically ill | Basal insulin (glargine, detemir, degludec) + rapid-acting with meals + correction scale |
| NPO (not eating) | Basal insulin at reduced dose (50–80%) + correction scale every 4–6 h |
| Receiving enteral nutrition (tube feeding) | Basal insulin + scheduled rapid-acting matched to feed schedule |
| Critically ill / ICU | IV insulin infusion with hourly glucose checks |
| DKA or HHS | IV insulin infusion until criteria met for transition to subcutaneous |
| Post-cardiac surgery | IV insulin infusion 24–48 h, then transition |
| Stable patient on insulin pump (selected) | Continue home pump if patient capable, facility allows |
Why Sliding Scale Alone Is Inferior
Sliding scale (rapid-acting given for high glucose readings without scheduled basal) is reactive rather than preventive — by the time a fingerstick shows 250 mg/dL, the patient has already been in that range for hours. The landmark RABBIT-2 trial (Umpierrez et al, 2007) randomly assigned hospitalized type 2 diabetes patients to sliding scale alone versus basal-bolus with correction. Basal-bolus produced lower mean glucose, fewer hyperglycemic days, fewer complications, and no increase in severe hypoglycemia. Most major guidelines now recommend basal-bolus as the default; sliding scale should be a correction layer, not the entire regimen.
Managing DKA and HHS Inpatient
- Initial IV fluid resuscitation — typically isotonic saline at 1 L/h for first 1–2 hours, then adjusted
- Potassium replacement — start when K+ falls below 5.3 mEq/L, before starting insulin if K+ under 3.3
- IV regular insulin infusion at 0.05 to 0.1 units/kg/hr (DKA) or 0.025 to 0.05 (HHS)
- Hourly glucose, electrolytes every 2–4 hours
- Switch IV fluid to D5-containing when glucose reaches 200 (DKA) or 300 (HHS)
- Bicarbonate only for severe acidosis (pH under 6.9) — not routine
- Transition to subcutaneous when anion gap closed, bicarbonate over 18, patient eating — overlap IV with subcutaneous basal for at least 2 hours
Managing Inpatient Hypoglycemia
| Glucose | Conscious, NPO | Conscious, Eating | Unconscious |
|---|---|---|---|
| 54–70 mg/dL | 15 g IV D50 or D10 | 15 g oral fast carbs | IV D50 50 mL |
| Below 54 mg/dL | 25 g IV D50 | 20–30 g oral fast carbs | IV D50 50 mL; consider glucagon if no IV |
| Recurrent hypoglycemia | Reduce basal; investigate cause | Reduce next bolus; adjust scheduled basal | Stop IV insulin; investigate |
| Documentation | Repeat glucose in 15 min until >70 | Same | Same |
Steroid-Induced Hyperglycemia
- Corticosteroids raise glucose, especially post-meal and afternoon
- Most pronounced 4 to 12 hours after a morning prednisone dose
- NPH insulin given with morning steroid often controls afternoon peak
- Basal-bolus insulin doses may need 30 to 50 percent increase during steroid course
- Anticipate dose reduction as steroid tapers
- Patients without prior diabetes may need insulin during steroid course — most do not need long-term — see our steroid-induced diabetes article
Stress Hyperglycemia in Non-Diabetic Patients
- Glucose over 140 mg/dL in a hospitalized patient without known diabetes
- Causes: critical illness, infection, infarction, surgery, steroids, parenteral nutrition
- Treat to standard inpatient targets (140 to 180)
- Check A1C during admission if not done in past 3 months
- A1C above 6.5 percent — likely undiagnosed diabetes; refer for outpatient follow-up
- A1C 5.7 to 6.4 percent — prediabetes; lifestyle counseling and rescreening in 6 months
- A1C below 5.7 percent — pure stress hyperglycemia; usually resolves with recovery but still carries 50 percent risk of future diabetes within 5 years
Medication Reconciliation
| Step | Action |
|---|---|
| Admission | Compare current home medications against admission orders; identify holds and substitutions |
| Transitions (ICU to floor) | Re-verify; transition from IV to subcutaneous insulin requires overlap |
| Pre-discharge | Side-by-side comparison: home meds, inpatient meds, discharge meds — flag changes |
| Discharge education | Written list in patient’s language; teach-back to confirm understanding |
| Post-discharge | Pharmacist follow-up call within 72 hours; clinician visit within 2 weeks |
Discharge Planning
- Medication reconciliation as above
- Written sick day rules — see our sick day rules guide
- Hypoglycemia recognition and treatment instructions
- Glucagon prescription if on insulin or sulfonylureas — teach a household member
- Glucose meter and strips at home — confirm patient has them
- Diabetes self-management education (DSME) — inpatient consult or outpatient referral
- Nutrition consultation if dietary changes are needed
- Follow-up appointment within 1 to 2 weeks (sooner for new insulin start or DKA/HHS admission)
- Specialist referral for complex cases — endocrinology, podiatry, ophthalmology, nephrology
- Communication with primary care clinician before discharge
Inpatient Diabetes Educator and Specialist Consults
- Most academic hospitals have inpatient diabetes management teams or consult services
- Indications include: DKA, HHS, persistent hyperglycemia despite basic management, new insulin start, severe hypoglycemia, pregnancy with diabetes, complex regimens, insulin pump or CGM use
- Early consultation reduces length of stay and improves discharge outcomes
- Inpatient diabetes self-management education improves post-discharge adherence and reduces readmission
Related Reading
For pre- and post-hospital care, see our guides on surgery and diabetes, sick day rules, and the broader treatment options overview.
The Bottom Line
Hospital diabetes management targets 140 to 180 mg/dL using basal-bolus subcutaneous insulin or IV insulin infusion — not sliding scale alone. ICU and post-cardiac surgery patients tolerate IV insulin with tighter targets; ward patients do better on scheduled basal plus mealtime plus correction. Steroid-induced and stress hyperglycemia require active management even in patients without prior diabetes diagnoses, with A1C testing during admission to catch undiagnosed disease. Discharge planning is the make-or-break step — medication reconciliation, written instructions, diabetes education, and follow-up within 2 weeks prevent the readmissions that account for a large fraction of avoidable diabetes admissions.
