Biphasic Insulin for Severe Hyperglycemia (RBS 715)
No, biphasic (pre-mixed) insulin should not be given as a one-time dose for severe hyperglycemia with RBS 715 mg/dL. Premixed insulin therapy has been associated with an unacceptably high rate of iatrogenic hypoglycemia and is not recommended in the hospital setting for acute hyperglycemia management 1.
Why Biphasic Insulin is Inappropriate for This Situation
- Premixed insulin (human insulin 70/30) carries an unacceptably high hypoglycemia risk in hospitalized patients and is explicitly not recommended for inpatient acute hyperglycemia management 1
- The fixed ratio of short-acting and intermediate-acting insulin in biphasic formulations cannot be adjusted to match the unpredictable insulin requirements during acute severe hyperglycemia 1
- Biphasic insulin is designed for chronic outpatient management with regular meal patterns, not for acute glycemic crises 2, 3
Recommended Approach for RBS 715 mg/dL
Immediate Management
- For severe hyperglycemia (RBS 715 mg/dL), initiate rapid-acting insulin (aspart, lispro, or glulisine) at 0.1-0.2 units/kg body weight as the initial dose 4
- Recheck blood glucose in 4 hours, which aligns with the duration of action of short-acting insulin 4
- Assess for diabetic ketoacidosis or hyperosmolar hyperglycemic state, which may require continuous intravenous insulin infusion 1
Transition to Scheduled Insulin Regimen
- Once stabilized, implement a basal-bolus regimen with long-acting basal insulin (glargine or detemir) plus rapid-acting insulin before meals 1
- For insulin-naive patients or those on low-dose insulin, start with total daily dose of 0.3-0.5 units/kg, with half as basal insulin 5
- For patients already on higher insulin doses (≥0.6 units/kg/day), reduce the total daily dose by 20% to prevent hypoglycemia 5
Monitoring Requirements
- Monitor blood glucose every 4-6 hours initially until glucose levels stabilize 4
- Once eating, check blood glucose before meals and at bedtime 4
- Target glucose range of 7.8-10.0 mmol/L (140-180 mg/dL) for most hospitalized patients 1
Critical Pitfalls to Avoid
- Never rely on sliding-scale insulin alone for patients with established diabetes—this approach is condemned in clinical guidelines and leads to poor glycemic control 1
- Do not use biphasic insulin in the hospital setting due to high hypoglycemia risk and inability to adjust components independently 1
- Avoid attempting to achieve euglycemia (80-110 mg/dL) in acute settings, as this substantially increases hypoglycemia risk without improving outcomes 1
- Do not delay assessment for diabetic ketoacidosis in patients with severe hyperglycemia, especially those with type 1 diabetes 4
Special Considerations
- If the patient has type 1 diabetes, never use sliding-scale insulin alone—a basal-bolus regimen is mandatory 1
- For patients on glucocorticoids, insulin requirements may be significantly higher, particularly in the afternoon and evening 5
- Patients with renal impairment require dose reductions due to decreased insulin clearance 4
- Older patients (>65 years), those with renal failure, or those with poor oral intake should receive lower initial doses (0.1-0.25 units/kg/day) 5