What is the management for a diabetic patient with hyperglycemia who has missed insulin for a week?

Management of Diabetic Patient with Hyperglycemia After Missing Insulin for a Week

A diabetic patient with blood glucose of 400 mg/dL who has missed insulin for a week requires immediate intravenous insulin therapy to prevent progression to diabetic ketoacidosis or hyperosmolar hyperglycemic state.

Initial Assessment and Management

• Obtain immediate blood glucose, venous blood gases, electrolytes, blood urea nitrogen (BUN), creatinine, calcium, phosphorous, and urine analysis to assess for ketosis and other metabolic abnormalities 1
• Check for ketones in urine or blood to rule out diabetic ketoacidosis (DKA) 1
• If ketones are present (ketonuria 2+ or ketonaemia ≥1.5 mmol/L), transfer to ICU for intravenous insulin infusion therapy 1
• Assess hydration status and initiate fluid replacement with normal saline at 1.5 times maintenance requirements (approximately 5 ml/kg/h) 1

Insulin Therapy Protocol

For Patients Without Significant Ketosis:

• Initiate intravenous insulin infusion at 0.1 U/kg/hour for patients with severe hyperglycemia 2
• Target blood glucose range of 150-250 mg/dL initially 2
• Monitor blood glucose every 1-2 hours until values and insulin infusion rates are stable, then every 4 hours 2
• Adjust insulin infusion rate according to algorithm:
  • If glucose >250 mg/dL: increase infusion by 1-2 U/hour
  • If glucose 150-250 mg/dL: maintain same rate
  • If glucose <150 mg/dL: decrease by 0.5-1 U/hour 2

For Patients With Mild DKA:

• For mild DKA without severe metabolic derangements, subcutaneous regular insulin every 4 hours may be considered 1
• This can be given in 5-unit increments for every 50 mg/dl increase in blood glucose above 150 mg/dl, up to 20 units for blood glucose of 300 mg/dl 1

Monitoring During Treatment

• Monitor serum potassium every 4-6 hours initially, as insulin therapy lowers serum potassium 1, 2
• Include potassium in intravenous fluids (1/3 KPO4 and 2/3 KCl or Kacetate) 1
• Monitor venous pH and anion gap to track resolution of acidosis if present 1
• Avoid rapid changes in blood glucose (not more than 50-75 mg/dL/hour) to prevent neurological complications 2

Transition to Subcutaneous Insulin

• Continue intravenous insulin until blood glucose is <200 mg/dL, serum bicarbonate is ≥18 mEq/L, and venous pH is >7.3 (if DKA was present) 1
• Calculate subcutaneous insulin requirements based on the total dose of intravenous insulin administered in the previous 12-24 hours 2
• Transition to a basal-bolus insulin regimen rather than sliding scale insulin alone, which is discouraged 1
• Maintain the intravenous insulin infusion for 1-2 hours after initiating subcutaneous insulin to ensure adequate insulin levels 2

Discharge Planning

• For patients with HbA1c <8%, schedule follow-up with primary care physician within one month 1
• For patients with HbA1c between 8-9%, arrange consultation with a diabetologist 1
• For patients with HbA1c >9% or persistent hyperglycemia (>250 mg/dL), consider referral to a diabetologist before discharge for possible specialized care 1

Common Pitfalls to Avoid

• Do not rely on sliding scale insulin alone without basal insulin, as this approach is ineffective and discouraged 1
• Do not use nitroprusside method (urine ketones) to monitor response to therapy in DKA, as β-hydroxybutyrate (the predominant ketone) is not measured by this method 1
• Avoid rapid correction of glucose to prevent complications such as cerebral edema 1, 2
• Be vigilant for hypoglycemia during insulin therapy, though the target range of 150-250 mg/dL reduces this risk 2