Management of Severe Hyperglycemia
The management of severe hyperglycemia (blood glucose 489 mg/dL) requires immediate fluid resuscitation with isotonic saline, insulin therapy, electrolyte replacement, and identification of precipitating causes. 1
Initial Assessment
- Evaluate for signs of diabetic ketoacidosis (DKA) or hyperglycemic hyperosmolar state (HHS) by checking serum ketones, arterial pH, bicarbonate, osmolality, and mental status 1
- Assess for dehydration, which is typically more severe in HHS (9 liters or 100-200 ml/kg total body water deficit) compared to DKA 1
- Identify potential precipitating factors including infection, missed insulin doses, medications (corticosteroids, diuretics, beta-blockers), or intercurrent illness 2
- Monitor for altered mental status, which may indicate cerebral edema, a rare but potentially fatal complication 2
Fluid Therapy
- Begin aggressive fluid resuscitation with isotonic saline (0.9% NaCl) at 15-20 ml/kg/hour during the first hour to restore circulatory volume and tissue perfusion 1
- After hemodynamic stability is achieved, switch to 0.45% saline if corrected sodium is normal or elevated 1
- Target correction of estimated fluid deficits within the first 24 hours, with induced change in serum osmolality not exceeding 3 mOsm/kg/h 1
- Continue monitoring fluid input/output and hemodynamic parameters to assess progress with fluid replacement 1
Insulin Therapy
- After excluding hypokalemia, administer an intravenous bolus of regular insulin at 0.15 U/kg body weight, followed by a continuous infusion at 0.1 U/kg/h 1
- If plasma glucose does not fall by 50 mg/dL from initial value in the first hour, double the insulin infusion rate every hour until a steady glucose decline between 50-75 mg/h is achieved 1
- When blood glucose reaches 250-300 mg/dL, add dextrose to the hydrating solution while continuing insulin infusion at a reduced rate 1
- Continue insulin infusion until mental status improves and hyperosmolarity resolves in HHS, or until ketoacidosis resolves in DKA 1, 3
Electrolyte Management
- Monitor and replace potassium, as total body deficits in hyperglycemic crises typically include 4-6 mEq/kg of potassium 1
- Once renal function is assured and serum potassium is known, add 20-40 mEq/L potassium to the infusion 1
- Monitor for phosphate deficiency, especially in patients with cardiac dysfunction, anemia, or respiratory depression 1
- Draw blood every 2-4 hours to determine serum electrolytes, glucose, blood urea nitrogen, creatinine, and osmolality 1
Transition to Subcutaneous Insulin
- When transitioning from intravenous to subcutaneous insulin, administer basal insulin 2-4 hours before stopping the intravenous insulin to prevent rebound hyperglycemia 1
- Start a multiple-dose schedule using a combination of short/rapid-acting and intermediate/long-acting insulin when the patient is able to eat 3
Complications to Monitor
- Watch for hypoglycemia due to overzealous insulin treatment 2
- Monitor for hypokalemia due to insulin administration and treatment of acidosis 2
- Be alert for signs of cerebral edema, including lethargy, behavioral changes, seizures, incontinence, pupillary changes, bradycardia, and respiratory arrest 1
- Watch for hyperchloremic metabolic acidosis from excessive saline administration 2
Prevention of Recurrence
- Provide education on sick-day management, including when to contact healthcare providers, blood glucose goals, supplemental insulin use during illness, and maintaining hydration 2
- Emphasize the importance of never discontinuing insulin during illness 2
- Ensure patients can accurately measure and record blood glucose, ketones when blood glucose exceeds 300 mg/dL, and communicate this information to healthcare providers 2
- Address socioeconomic barriers to insulin access, as stopping insulin for economic reasons is a common precipitant of DKA 2