Protocol for Managing Hyperosmolar Hyperglycemic State (HHS)
The management of Hyperosmolar Hyperglycemic State (HHS) requires aggressive fluid resuscitation as the primary intervention, followed by careful insulin administration and electrolyte replacement to reduce mortality and prevent complications. 1, 2
Diagnosis and Initial Assessment
- HHS is diagnosed by blood glucose >600 mg/dl, arterial pH >7.3, bicarbonate >15 mEq/l, mild ketonuria or ketonemia, and effective serum osmolality >320 mOsm/kg H₂O 3, 1
- Calculate effective serum osmolality using the formula: 2[measured Na (mEq/l)] + glucose (mg/dl)/18 4
- Obtain arterial blood gases, complete blood count, urinalysis, blood glucose, BUN, electrolytes, chemistry profile, and creatinine levels STAT 3, 1
- Assess for precipitating factors including infection, myocardial infarction, stroke, medications (diuretics, corticosteroids, beta-blockers), and other acute illnesses 1, 5
Fluid Resuscitation Protocol
- 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 expand intravascular volume and restore renal perfusion 1, 2
- After initial resuscitation, adjust fluid choice based on corrected serum sodium:
- Target fluid replacement should correct estimated deficits within the first 24 hours 3, 1
- Monitor the rate of change in serum osmolality - should not exceed 3-8 mOsm/kg/h to prevent neurological complications 4, 2
Insulin Therapy Protocol
- Important: Fluid replacement alone will cause a fall in blood glucose level 6
- Withhold insulin until blood glucose is no longer falling with IV fluids alone, unless ketonaemia is present 6, 2
- Once insulin is started, administer as continuous intravenous infusion at 0.1 U/kg/h (typically 5-10 units/hour) 3, 1
- When plasma glucose reaches 300 mg/dl, decrease insulin infusion to 0.05-0.1 U/kg/h (3-6 U/h) 4, 1
- Add 5-10% dextrose to IV fluids when glucose falls below 300 mg/dl to prevent hypoglycemia while continuing to treat hyperosmolarity 4, 1
- Target glucose level between 250-300 mg/dl until hyperosmolarity resolves 1
Electrolyte Replacement
- Once renal function is assured (urine output ≥0.5 ml/kg/h) and serum potassium is known, add potassium to the infusion: 3, 1
- Monitor electrolytes (sodium, potassium, chloride, bicarbonate, phosphate, magnesium) every 2-4 hours during initial treatment 1
Monitoring Protocol
- Monitor vital signs, mental status, fluid input/output, and hemodynamic parameters hourly 1
- Check blood glucose every 1-2 hours until stable 1
- Calculate effective serum osmolality regularly to guide fluid management 4, 1
- Correct serum sodium for hyperglycemia: add 1.6 mEq to sodium value for each 100 mg/dl glucose >100 mg/dl 4
- Monitor for complications including cerebral edema, myocardial infarction, stroke, and vascular thrombosis 1, 7
Transition to Subcutaneous Insulin
- Administer basal insulin 2-4 hours before discontinuing intravenous insulin to prevent rebound hyperglycemia 1
- Consider low-dose basal insulin analog in addition to intravenous insulin infusion 1
Resolution Criteria
- Effective serum osmolality <300 mOsm/kg 2
- Hypovolemia corrected (urine output ≥0.5 ml/kg/h) 2
- Cognitive status returned to pre-morbid state 2
- Blood glucose <15 mmol/L (270 mg/dL) 2
Special Considerations
- Elderly patients and those with cardiac/renal compromise require more cautious fluid rates with closer monitoring 4, 1
- In pediatric patients (<20 years), initial fluid therapy should be isotonic saline at 10-20 ml/kg/h, but initial reexpansion should not exceed 50 ml/kg over first 4 hours 3
- Mixed DKA/HHS may occur and requires adjustments to the treatment approach 2
- Avoid excessive fluid administration in patients with cardiac or renal compromise 1
- The diabetes specialist team should be involved as soon as possible 6