What is the management for a patient with persistent severe hyperglycemia?

Management of Severe Hyperglycemia (Blood Glucose 500 mg/dL)

For a patient with persistent severe hyperglycemia with glucose levels of 500 mg/dL on repeat testing, immediate intravenous insulin therapy with aggressive fluid replacement is required to prevent life-threatening complications.

Initial Assessment and Stabilization

• Evaluate for signs of hyperosmolar hyperglycemic state (HHS) or diabetic ketoacidosis (DKA), including level of consciousness, degree of dehydration, vital signs, and respiratory status 1
• Obtain immediate laboratory tests: arterial blood gas, complete blood count, electrolyte panel, blood glucose, urea, creatinine, and urinalysis for ketones 1
• Calculate effective osmolality using the formula: 2[Na+ (mEq/l)] + glucose (mg/dl)/18 1
• Identify potential precipitating factors such as infection, medication non-compliance, trauma, myocardial infarction, or stroke 1

Emergency Treatment Protocol

• Begin immediate fluid replacement with 0.9% NaCl at 15-20 ml/kg/hour for the first hour 1
• Start continuous intravenous insulin infusion at 0.1 units/kg/hour after confirming potassium is not low (K+ ≥3.3 mEq/l) 1, 2
• If blood glucose does not decrease by at least 50 mg/dl in the first hour, double the insulin dose hourly until achieving a decrease of 50-75 mg/dl/hour 1
• The goal is to replace the estimated fluid deficit over 24 hours, with a decrease in osmolality of no more than 3 mOsm/kg/hour 1
• Monitor for hypokalemia, which can occur with insulin therapy and may lead to respiratory paralysis, ventricular arrhythmia, and death 2

Monitoring Requirements

• Monitor blood glucose hourly during the acute phase 1
• Check electrolytes, renal function, and level of consciousness every 2-4 hours 1
• Target blood glucose reduction to 180-270 mg/dl within 24 hours 1
• Watch for signs of cerebral edema if glucose falls too rapidly 3

Transition to Subcutaneous Insulin

• Once the patient is stable with blood glucose <300 mg/dL and able to eat, transition from IV to subcutaneous insulin 3
• For the transition, calculate the total daily insulin requirement based on the IV insulin rate over the previous 6-12 hours 3
• The initial subcutaneous insulin dose should be 60-80% of the calculated total daily IV insulin requirement 1
• Implement a basal-bolus insulin regimen with once-daily basal insulin (glargine/Optisulin) and rapid-acting insulin (aspart/Novorapid) with each meal at a total dose of 0.3-0.5 units/kg, split 50/50 between basal and bolus insulin 3
• For patients who may struggle with multiple daily injections, consider mixed insulin formulations such as Novomix 30 3

Special Considerations

• For critically ill patients, maintain blood glucose between 140-180 mg/dL once insulin therapy is initiated 3
• For non-critically ill patients with severe hyperglycemia, basal-bolus insulin regimens are preferred if they have good nutritional intake 3, 4
• Patients with severe hyperglycemia are at risk for hyperosmolar hyperglycemic state (HHS), which has significant mortality if not treated promptly 5
• Measure HbA1c during admission to assess chronic glycemic control and guide discharge planning 4

Discharge Planning

• Patients should receive education on glucose monitoring, symptoms of severe hyperglycemia, and hypoglycemia management 3
• For newly diagnosed type 2 diabetes, consider adding metformin once the acute condition has stabilized 1
• Ensure follow-up with endocrinology or primary care within 1-2 weeks of discharge 3
• Emphasize that persistent blood glucose readings above 300 mg/dL require immediate medical attention 3

Pitfalls to Avoid

• Do not delay insulin therapy for severe hyperglycemia as this increases risk of complications and mortality 6, 7
• Avoid excessive fluid administration in patients with heart failure or renal failure 1
• Be cautious about hypoglycemia during treatment, which can occur with aggressive insulin therapy 2
• Do not ignore glycemic variability, as higher variability is associated with increased mortality 7, 8
• Never administer insulin without checking potassium levels first, as insulin-induced hypokalemia can be fatal 2