Management of Hyperosmolar Hyperglycemic State (HHS)
The management of HHS requires immediate aggressive fluid resuscitation with isotonic saline (0.9% NaCl) at 15-20 mL/kg/h during the first hour, followed by insulin therapy and careful electrolyte management to correct severe dehydration and hyperglycemia while preventing complications from rapid osmolality changes. 1, 2
Diagnostic Criteria
- HHS is diagnosed based on blood glucose ≥600 mg/dL, arterial pH >7.3, serum bicarbonate >15 mEq/L, effective serum osmolality ≥320 mOsm/kg H₂O, and mild ketonuria or ketonemia 1
- Calculate effective serum osmolality using: 2[measured Na⁺ (mEq/L)] + glucose (mg/dL)/18 1, 2
- Correct serum sodium for hyperglycemia (for each 100 mg/dL glucose >100 mg/dL, add 1.6 mEq to sodium value) 2
Initial Assessment
- Obtain arterial blood gases, complete blood count, urinalysis, plasma glucose, blood urea nitrogen, electrolytes, chemistry profile, and creatinine levels immediately 1, 2
- Identify potential precipitating causes, especially infections, which are the most common triggers 3
- Assess mental status, vital signs, and hydration status 2
Fluid Therapy
- Begin with isotonic saline (0.9% NaCl) at 15-20 mL/kg/h (1-1.5 L in average adult) during the first hour to restore circulatory volume and renal perfusion 1, 2
- After hemodynamic stabilization, switch to 0.45% NaCl if corrected serum sodium is normal or elevated 2
- Total body water deficit in HHS is approximately 9 liters (100-200 mL/kg), with correction aimed over 24 hours 1
- Monitor fluid input/output, hemodynamic parameters, and mental status frequently 2
- Ensure the change in serum osmolality does not exceed 3 mOsm/kg/h to prevent cerebral edema 2, 4
- When blood glucose reaches 300 mg/dL, add 5-10% dextrose to IV fluids to prevent hypoglycemia while continuing insulin therapy 2
Insulin Therapy
- Important: Delay insulin therapy until fluid resuscitation has begun and hypokalemia (K⁺ <3.3 mEq/L) is excluded 5, 6
- Administer intravenous bolus of regular insulin at 0.15 units/kg body weight, followed by continuous infusion at 0.1 unit/kg/h (5-7 units/h in adults) 1, 2
- If plasma glucose does not fall by 50 mg/dL in the first hour, check hydration status; if acceptable, double insulin infusion rate hourly until steady glucose decline of 50-75 mg/h is achieved 5, 2
- When plasma glucose reaches 300 mg/dL, decrease insulin infusion to 0.05-0.1 unit/kg/h (3-6 units/h) 1, 2
- Continue insulin therapy until mental obtundation and hyperosmolarity are resolved 2
Electrolyte Management
- Once renal function is assured and serum potassium is known, add 20-40 mEq/L potassium (2/3 KCl or potassium acetate and 1/3 KPO₄) to IV fluids 5, 1
- Monitor serum electrolytes every 2-4 hours during initial treatment 1, 2
- Address other electrolyte imbalances (magnesium, phosphate, calcium) as needed 2
Monitoring During Treatment
- Check blood glucose every 1-2 hours until stable 1
- Draw blood every 2-4 hours to determine serum electrolytes, glucose, blood urea nitrogen, creatinine, and osmolality 1, 2
- Assess mental status frequently to monitor improvement 2
Transition to Subcutaneous Insulin
- Administer basal insulin 2-4 hours before stopping IV insulin to prevent rebound hyperglycemia 1, 2
- When the patient can eat, initiate a multiple-dose insulin regimen with combination of short/rapid-acting and intermediate/long-acting insulin 2
Complications to Monitor
- Cerebral edema, especially with rapid correction of osmolality 2, 4
- Fluid overload in patients with renal or cardiac compromise 2
- Rhabdomyolysis, renal failure, and respiratory distress 6
- Hypercoagulable state leading to thrombotic events 6
- Central pontine myelinolysis with rapid changes in osmolality 4