What is the step-by-step treatment protocol with insulin dose for a patient with severe hyperglycemia?

Step-by-Step Insulin Treatment Protocol for Severe Hyperglycemia

Initial Assessment and Insulin Initiation Threshold

Insulin therapy should be initiated when blood glucose is ≥180 mg/dL (confirmed on two occasions within 24 hours) for both critically ill and noncritically ill patients. 1

Critical Care Setting (ICU Patients)

Continuous intravenous insulin infusion is the preferred and most effective method for achieving glycemic targets in critically ill patients. 1

Step 1: Determine Initial IV Insulin Dose

• For insulin-naive or low-dose insulin patients: Start with total daily dose of 0.3-0.5 units/kg, with half given as basal insulin 2
• For patients on high-dose home insulin (≥0.6 units/kg/day): Reduce total daily dose by 20% to prevent hypoglycemia 2
• For high-risk patients (elderly >65 years, renal failure, poor oral intake): Use lower doses of 0.1-0.25 units/kg/day 2

Step 2: Target Glucose Range

• Target blood glucose: 140-180 mg/dL (7.8-10.0 mmol/L) 1, 3, 4
• Avoid targets <110 mg/dL due to increased hypoglycemia risk without mortality benefit 1

Step 3: Monitoring Protocol

• Monitor blood glucose every 2-4 hours during active IV insulin infusion 1
• Use validated written or computerized protocols that allow predefined adjustments based on glycemic fluctuations 1

Step 4: Transition to Subcutaneous Insulin

• Calculate basal insulin dose based on the last 6 hours of stable IV insulin infusion rate 1
• Continue IV insulin for 1-2 hours after starting subcutaneous regimen to prevent hyperglycemic rebound 1

Noncritical Care Setting (Non-ICU Patients)

Scheduled subcutaneous basal-bolus insulin regimen is the preferred treatment for patients with adequate nutritional intake. 1

Step 1: Initial Subcutaneous Insulin Dosing

For Mild-Moderate Hyperglycemia (A1C <8.5%, glucose <250 mg/dL, asymptomatic):

• Start with basal insulin only: 10 units once daily OR 0.1-0.2 units/kg/day 1, 2
• Administer at the same time each day 5

For Severe Hyperglycemia (glucose ≥250 mg/dL, A1C ≥8.5%, symptomatic with polyuria/polydipsia/weight loss):

• Start basal insulin at 0.5 units/kg/day while initiating metformin 1
• For patients with blood glucose ≥300-350 mg/dL or A1C 10-12% with catabolic features: Start basal-bolus regimen immediately with 0.4-0.6 units/kg/day total daily dose 2

For Diabetic Ketoacidosis (DKA):

• Give priming dose of regular insulin 0.4-0.6 units/kg body weight: half as IV bolus, half as subcutaneous/intramuscular injection 1
• Then 0.1 unit/kg regular insulin subcutaneously or intramuscularly every hour 1
• Once acidosis resolves (glucose <200 mg/dL, bicarbonate ≥18 mEq/L, pH >7.3), transition to subcutaneous basal-bolus regimen 1

Step 2: Basal Insulin Titration Algorithm

Titrate based on fasting plasma glucose (FPG) every 3 days: 1, 2

• If FPG ≥180 mg/dL: Increase by 4 units
• If FPG 140-179 mg/dL: Increase by 2 units
• If FPG 80-130 mg/dL: Maintain current dose (target achieved)
• If FPG <70 mg/dL: Decrease by 10-20% immediately 1

Alternative titration: Increase by 10-15% or 2-4 units once or twice weekly until FPG reaches 80-130 mg/dL 2

Step 3: Adding Prandial Insulin (When Needed)

Add prandial insulin when:

• Basal insulin optimized (FPG 80-130 mg/dL) but A1C remains above goal after 3-6 months 2
• Basal insulin dose approaches 0.5-1.0 units/kg/day without achieving A1C goal 1, 2
• Postprandial glucose excursions persist despite adequate fasting control 2

Prandial insulin starting dose:

• 4 units of rapid-acting insulin before the largest meal OR 10% of current basal dose 2
• Titrate by 1-2 units or 10-15% every 3 days based on postprandial glucose 2

Step 4: Target Glucose Ranges for Noncritical Care

• Premeal glucose target: <140 mg/dL (7.8 mmol/L) 1
• Random glucose target: <180 mg/dL (10.0 mmol/L) 1
• Modify regimen if glucose falls <70 mg/dL (3.9 mmol/L) 1

Special Populations

For Patients on Enteral/Parenteral Nutrition:

• Start with 10 units insulin glargine every 24 hours OR 5 units NPH/detemir every 12 hours 2
• Basal insulin typically represents 30-50% of total daily insulin requirement 2

For Patients on Corticosteroids:

• Add 0.1-0.3 units/kg/day glargine to usual insulin regimen, adjusted based on steroid dose and oral intake 2

Critical Pitfalls to Avoid

• Never use sliding scale insulin (SSI) as sole therapy - it is strongly discouraged and leads to poor glycemic control 1
• Do not continue escalating basal insulin beyond 0.5-1.0 units/kg/day without adding prandial insulin - this causes "overbasalization" with increased hypoglycemia risk 2
• Do not delay titration - adjust basal insulin every 3 days during active titration phase 2
• Do not abruptly discontinue IV insulin - overlap with subcutaneous insulin for 1-2 hours to prevent rebound hyperglycemia 1
• Do not dilute or mix insulin glargine with any other insulin or solution 5
• Do not target glucose <110 mg/dL in critically ill patients - associated with increased hypoglycemia without benefit 1

Hypoglycemia Management Protocol

If glucose <70 mg/dL (3.9 mmol/L):

• Determine cause and reduce insulin dose by 10-20% 1
• Implement hypoglycemia prevention protocol 1
• Reassess insulin regimen when glucose <100 mg/dL (5.6 mmol/L) 1

Monitoring Requirements

• During IV insulin: Check glucose every 2-4 hours 1
• During subcutaneous titration: Daily fasting glucose monitoring essential 2
• After stabilization: Assess adequacy at every clinical visit 2