Initial Management of Hyperglycemic Hyperosmolar State (HHS)
The initial management of hyperglycemic hyperosmolar state (HHS) should prioritize aggressive fluid resuscitation with 0.9% normal saline at 15-20 mL/kg/hour for the first hour before starting insulin therapy, followed by careful electrolyte monitoring and correction. 1
Initial Assessment
When a patient presents with suspected HHS, perform immediate laboratory evaluation:
- Blood glucose (typically ≥30 mmol/L or 540 mg/dL)
- Arterial blood gas
- Complete blood count with differential
- Urinalysis (to check for glycosuria and rule out significant ketones)
- Electrolytes (including calcium and magnesium)
- BUN and creatinine
- Serum osmolality (≥320 mOsm/kg)
- ECG
- Chest radiograph
- Cultures as indicated 1
Calculate corrected sodium by adding 1.6 mEq to the sodium value for every 100 mg/dL of glucose >100 mg/dL 1
Treatment Algorithm
Phase 1 (0-60 minutes): Fluid Resuscitation
- Begin with 0.9% normal saline at 15-20 mL/kg/hour for the first hour 1
- Assess for signs of heart failure before aggressive fluid resuscitation
- Establish IV access, preferably two large-bore IVs
- Begin cardiac monitoring
Phase 2 (1-6 hours): Continue Fluid Replacement and Start Insulin
- Continue fluid replacement with 0.9% normal saline until hemodynamic stabilization is achieved 1
- Important: Withhold insulin until fluid replacement has been initiated and blood glucose is no longer falling with IV fluids alone (unless ketonaemic) 2
- When starting insulin, administer IV bolus of 0.15 U/kg of regular insulin, followed by continuous infusion at 0.1 U/kg/hour (approximately 5-7 U/hour in adults) 1
- Begin potassium replacement once renal function is confirmed and serum potassium levels are known 1
Phase 3 (6-12 hours): Monitoring and Adjustment
- Adjust insulin infusion rate to achieve glucose decrease of 50-75 mg/hour 1
- If glucose does not decrease by 50 mg/dL in the first hour, double the infusion rate every hour until a stable decrease is achieved 1
- Monitor electrolytes, BUN, creatinine every 2-4 hours
- Calculate serum osmolality regularly to monitor treatment response
- Aim to reduce osmolality by 3-8 mOsm/kg/hour to avoid neurological complications 2, 3
Phase 4 (12-24 hours): Transition Phase
- When glucose levels reach 300 mg/dL:
- Reduce insulin infusion rate to 0.05-0.1 U/kg/hour
- Add 5-10% dextrose to IV fluids 1
- Continue to monitor electrolytes and osmolality
- Switch to 0.45% saline after hemodynamic stabilization 1
Monitoring Parameters
- Blood glucose: hourly until stable
- Electrolytes, BUN, creatinine: every 2-4 hours
- Serum osmolality: calculate regularly
- Mental status: continuous assessment
- Vital signs: continuous monitoring
- Strict input/output monitoring 1
Treatment Goals
- Improve clinical status and replace fluid losses by 24 hours
- Gradual decline in osmolality (3-8 mOsm/kg/hour)
- Blood glucose 10-15 mmol/L (180-270 mg/dL) in the first 24 hours
- Prevent hypoglycemia and hypokalemia
- Prevent complications: venous thromboembolism, osmotic demyelination, fluid overload 3
Important Considerations and Pitfalls
Key Differences from DKA
- HHS develops over days (not hours like DKA)
- Dehydration and metabolic disturbances are more extreme
- Higher mortality rate than DKA 2
- May present with mixed HHS/DKA picture in some patients 3
Common Complications to Avoid
- Cerebral edema from too rapid correction of osmolality
- Central pontine myelinolysis from rapid changes in osmolality 2
- Hypoglycemia from excessive insulin
- Hypokalemia from inadequate replacement
- Fluid overload, especially in elderly patients or those with cardiac issues 3
Common Precipitating Factors to Identify and Treat
- Infection (most common)
- Medication non-adherence
- New-onset diabetes
- Acute illness (stroke, myocardial infarction)
- Alcohol or substance use 1
HHS resolution criteria include: osmolality <300 mOsm/kg, corrected hypovolemia (urine output ≥0.5 mL/kg/h), return to pre-morbid cognitive status, and blood glucose <15 mmol/L (270 mg/dL) 3.