Intern Survival Guide Topic

Inpatient insulin dosing.

Basal, nutritional, correction — build it, don't chase it. Weight-based total daily dose, a worked 80 kg example, correction dosing by insulin sensitivity, converting home regimens on admission, and the NPO/steroid/hypoglycemia rules that keep patients safe.

Reviewed June 2026 · verify against current guidelines

The Principle

Basal-Bolus, Not Sliding Scale

Why

Sliding-scale-only chases highs; it never prevents them.
Basal-bolus-correction improved control in RABBIT-2.
Three parts: basal, nutritional, correction.

Inpatient glucose targets (mg/dL)

Start scheduled insulin	When glucose is persistently ≥180.
Target range, most patients	140-180.
Target range, perioperative	100-180.
Treat hypoglycemia	Below 70. Do not aim for a target under 110.

Reactive correction without basal is the most common inpatient insulin error.

RABBIT-2 trial of basal-bolus vs sliding-scale insulin

Type 1 vs Type 2

Know Which You're Dosing

The disease decides the dose. Both use basal, nutritional, and correction insulin.

Two diseases, two doses

	Type 1	Type 2
Core problem	Insulin deficiency	Insulin resistance
Start at	0.4-0.5 units/kg/day, split 50/50	Basal 0.2-0.3 units/kg + 0.05 units/kg/meal
Basal insulin	Always required	Usually needed
Hypoglycemia	Higher; sensitive	Lower
Key danger	DKA if basal stopped	Persistent highs

Initial totals end up similar, about 0.4-0.5 units/kg. Type 2 may need 1+ units/kg with obesity, resistance, or steroids.

TDD total daily doseDKA diabetic ketoacidosis

Build & Correct

Dose, Then Correct

80 kg, type 2 diabetes, eating, BG 250, normal renal function.

Build the regimen

Basal	0.25 × 80 = 20 units glargine daily.
Prandial	0.05 × 80 = 4 units rapid per meal.
Correction	Add rapid-acting for BG ≥150.
Initial TDD	About 32 units/day, then titrate.

Pick the correction scale

Insulin-sensitive	Low TDD, elderly, renal impairment, insulin-naive.
Usual	Most patients.
Insulin-resistant	High TDD, obesity, or on steroids.

Use 0.15-0.2 units/kg basal for elderly, renal impairment, or hypoglycemia risk. Correction supplements basal-bolus, never alone: shift toward resistant if highs persist, toward sensitive after a low.

BG blood glucoseTDD total daily dose

On Admission

Convert the Home Regimen

Continue, but adjust

Reduce doses	Basal 10-20% less; prandial 25-50% less for variable intake.
Type 1	Never stop basal, even when NPO. DKA risk.
Keep structure	Basal stays scheduled; convert meals to nutritional plus correction.
Non-insulin agents	Often hold metformin, SGLT2, and sulfonylureas inpatient.

Stopping basal in type 1 to 'avoid lows' causes DKA. Reduce, do not stop.

TDD total daily doseNPO nothing by mouthDKA diabetic ketoacidosisSGLT2 sodium-glucose cotransporter-2 inhibitor

Daily Titration

Adjust for Highs and Lows

The timing of the abnormal glucose tells you which insulin to move. Fasting glucose tracks basal; a pre-meal number tracks the rapid-acting dose before it. Change in 10-20% steps, one component at a time, on the trend over 1-2 days.

Read the pattern, pick the insulin

Glucose pattern	What to change
Fasting / pre-breakfast high	Basal (long-acting) up 10-20%.
Overnight or fasting low	Basal (long-acting) down 10-20%.
High before lunch, dinner, or bed	Raise rapid-acting (short) at the meal before.
Low after a meal	Lower rapid-acting (short) at that meal.
High all day, heavy correction use	Add the 24h correction total into scheduled basal and prandial.

Fix lows first, and cut more for severe or unexplained hypoglycemia. Titrate on the pattern, not a single reading.

basal long-acting insulinrapid / prandial short-acting mealtime insulin

Adjust & Protect

NPO, Steroids, Lows

Common curveballs

NPO	Continue basal (10-20% less). Hold nutritional. Keep correction.
Steroids	Daytime highs. Add NPH with morning prednisone; titrate up.
Hypoglycemia	Treat under 70: 15 g oral glucose, or IV D50. Recheck in 15 min.
Renal / elderly	Lower TDD. Higher hypoglycemia risk; titrate slowly.

Below 54 mg/dL is clinically significant hypoglycemia. Act fast and find the cause.

NPO nothing by mouthNPH intermediate-acting insulinD50 50% dextrose

Sources

Verify against current guidelines and local protocol before acting.

ADA. 16. Diabetes Care in the Hospital. Standards of Care in Diabetes 2026. Diabetes Care 2026;49(Suppl 1):S339.
ADA. 6. Glycemic Goals, Hypoglycemia, and Hyperglycemic Crises. Standards of Care in Diabetes 2026.
Umpierrez GE et al. RABBIT-2: basal-bolus vs sliding-scale insulin in non-ICU type 2 diabetes. Diabetes Care 2007;30:2181.
NICE-SUGAR Study Investigators (Finfer S et al). Intensive versus conventional glucose control in critically ill patients. N Engl J Med 2009;360(13):1283.
Umpierrez GE et al. RABBIT-2 Surgery. Diabetes Care 2011;34:256.
Inpatient Diabetes Management. Endotext / Endocrine Society (weight-based dosing).
UpToDate. Glycemic Management in Hospitalized Adults With Diabetes Mellitus (2026).

Downloads

Every card for this topic — carousels and tables, print-ready for the wards or for sharing.

Carousel8 slides