What should be included in the orders when prescribing regular insulin for a patient with potential impaired renal function and other underlying medical conditions?

Ordering Regular Insulin: Essential Components for Safe Administration

When ordering regular insulin for a patient, you must specify the dose, frequency, timing relative to meals (30-45 minutes before), blood glucose monitoring schedule, correction scale parameters, and hypoglycemia management protocols. 1, 2, 3

Core Order Components

1. Insulin Regimen Structure

• Never order sliding scale insulin as monotherapy – this approach is explicitly condemned by all major diabetes guidelines and leads to dangerous glucose fluctuations 1, 2, 3
• Order a scheduled basal-bolus regimen with basal insulin (50% of total daily dose) plus regular insulin before meals (remaining 50% divided among three meals) 1, 3
• For hospitalized patients who are insulin-naive, start with 0.3-0.5 units/kg/day total daily dose, with half as basal insulin 3

2. Regular Insulin Dosing and Timing

• Administer regular insulin 30-45 minutes before meals – this is critical as regular insulin has a slower onset than rapid-acting analogs 3, 4
• For prandial coverage, start with 4 units before the largest meal or use 10% of the basal dose 2, 3
• Titrate by 1-2 units every 3 days based on 2-hour postprandial glucose readings 2, 3

3. Blood Glucose Monitoring Requirements

• Order bedside glucose monitoring before each meal and at bedtime for patients eating regular meals 1, 3
• For patients not eating (NPO), order glucose checks every 4-6 hours 1, 3
• Daily fasting blood glucose monitoring is essential during titration 2, 3

4. Target Glucose Ranges

• Fasting glucose target: 80-130 mg/dL 1, 2, 3
• Postprandial glucose target: <180 mg/dL 1, 3
• For hospitalized patients, target glucose range is 140-180 mg/dL for the majority of critically ill and non-critically ill patients 1

5. Correction Insulin Protocol

• Add correction doses using regular insulin for premeal glucose >180 mg/dL, separate from scheduled doses 3
• Use simplified sliding scale as adjunct only: 2 units for glucose >250 mg/dL, 4 units for glucose >350 mg/dL 3
• Never give regular insulin at bedtime to avoid nocturnal hypoglycemia 3

6. Special Considerations for Renal Impairment

• For patients with history of hypoglycemia and potential renal impairment, start with conservative basal insulin dose of 0.1 units/kg/day 2
• For eGFR <45 mL/min/1.73 m², titrate conservatively to avoid hypoglycemia 2, 3
• For CKD Stage 5, reduce total daily insulin dose by 50% for type 2 diabetes or 35-40% for type 1 diabetes 2, 3

7. Hypoglycemia Management Orders

• Order glucagon for emergent hypoglycemia 2
• Specify treatment protocol: 15 grams of fast-acting carbohydrate for blood glucose ≤70 mg/dL 2, 3
• If hypoglycemia occurs without clear cause, immediately reduce dose by 10-20% 2, 3

8. Foundation Therapy

• Continue metformin unless contraindicated (eGFR <30 mL/min/1.73 m²) 2, 3
• Metformin reduces total insulin requirements and provides complementary glucose-lowering effects 2, 3

9. Titration Instructions

• For fasting glucose 140-179 mg/dL: increase basal insulin by 2 units every 3 days 2, 3
• For fasting glucose ≥180 mg/dL: increase basal insulin by 4 units every 3 days 2, 3
• For high-risk patients (elderly >65 years, renal impairment, history of hypoglycemia), use maximum 2-unit increments every 3 days 2

10. Critical Threshold Warning

• When basal insulin exceeds 0.5 units/kg/day, add prandial insulin rather than continuing to escalate basal insulin alone 2, 3
• Signs of overbasalization include: basal dose >0.5 units/kg/day, bedtime-to-morning glucose differential ≥50 mg/dL, hypoglycemia, and high glucose variability 2, 3

Common Pitfalls to Avoid

• Do not use standard starting doses (0.2 units/kg/day) in high-risk patients with history of hypoglycemia or renal impairment 2
• Do not delay dose reduction when hypoglycemia occurs – 75% of hospitalized patients who experienced hypoglycemia had no insulin dose adjustment before the next administration 3
• Do not rely solely on sliding scale adjustments – scheduled insulin doses must be adjusted based on patterns 3
• Do not give rapid-acting or regular insulin at bedtime as this increases nocturnal hypoglycemia risk 3

Administration and Storage

• Regular insulin should not be diluted or mixed with other insulin preparations 5
• Insulin is not intended for intravenous or intramuscular administration when ordering subcutaneous regular insulin 5
• Continuous rotation of injection sites within a given area helps reduce lipodystrophy 5