What is the treatment for Hyperosmolar Hyperglycemic State (HHS)?

Treatment of Hyperosmolar Hyperglycemic State (HHS)

The core treatment for HHS consists of careful fluid resuscitation with 0.9% sodium chloride (15-20 mL/kg/hour) followed by insulin therapy, with the goal of correcting fluid deficit within 24 hours while avoiding rapid changes in osmolality. 1

Diagnostic Criteria for HHS

• Plasma glucose ≥600 mg/dL (≥33.3 mmol/L)
• Effective serum osmolality ≥320 mOsm/kg H₂O
• Arterial pH >7.3
• Serum bicarbonate >15 mEq/L
• Minimal or no ketones in urine and serum
• Altered mental status (typically stupor/coma) 1

Initial Assessment

• Obtain arterial blood gases, complete blood count, urinalysis, blood glucose, BUN, electrolytes, and creatinine
• Calculate effective serum osmolality using: 2[measured Na⁺ (mEq/L)] + glucose (mg/dL)/18
• Assess for underlying precipitating causes (infections most common) 1, 2
• Obtain appropriate cultures if infection is suspected 1

Treatment Algorithm

Phase 1: Fluid Resuscitation (First Priority)

1. Begin with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour 1

   • Note: Total fluid losses in HHS can be 100-220 mL/kg 3
   • Use caution in elderly patients and those with cardiac or renal disease 1, 3

2. After initial stabilization, adjust fluid type based on corrected sodium:

   • For normal or elevated corrected sodium: Switch to 0.45% NaCl at 4-14 mL/kg/hour
   • For low corrected sodium: Continue 0.9% NaCl 1

3. Important: Fluid replacement alone will cause a fall in blood glucose level 4

Phase 2: Insulin Therapy

1. Only initiate insulin after starting fluid replacement and ruling out hypokalemia 1

   • Consider withholding insulin until blood glucose stops falling with IV fluids alone (unless ketonaemia is present) 4

2. When starting insulin:

   • Initial dose: 0.15 U/kg IV bolus
   • Follow with continuous infusion at 0.1 U/kg/hour
   • Adjust to achieve glucose decrease of 50-75 mg/dL/hour 1

3. Add glucose infusion (5% or 10%) once blood glucose falls below 250-300 mg/dL (14 mmol/L) to prevent hypoglycemia 1, 3

Phase 3: Electrolyte Management

1. Potassium replacement:

   • Add potassium to IV fluids once renal function is confirmed and serum potassium is known
   • Typical dose: 20-30 mEq/L (2/3 KCl and 1/3 KPO₄) 1

2. Monitor and replenish magnesium, calcium, and phosphate as needed 1

Monitoring During Treatment

• Vital signs, hemodynamic status, and mental status
• Fluid intake/output
• Electrolytes, glucose, BUN, creatinine
• Serum osmolality: Target reduction of 3-8 mOsm/kg/hour to prevent neurological complications 1, 3, 4
• Blood glucose: Target 180-270 mg/dL (10-15 mmol/L) in first 24 hours 3

Resolution Criteria

HHS is considered resolved when:

• Blood glucose <300 mg/dL
• Serum osmolality <315 mOsm/kg
• Patient is alert and able to ingest liquids 1
• Hypovolemia corrected (urine output ≥0.5 mL/kg/h) 3

Common Pitfalls and Complications to Avoid

1. Failing to recognize mixed DKA/HHS presentations 1, 3
2. Initiating insulin before adequate fluid resuscitation 1, 4
3. Rapid correction of osmolality (can lead to cerebral edema or central pontine myelinolysis) 1, 4
4. Other complications to monitor for:
   • Hypoglycemia
   • Hypokalemia
   • Hypernatremia
   • Thromboembolism 1

Special Considerations

• HHS has a higher mortality rate than DKA 4
• HHS typically develops gradually over many days (unlike DKA which presents within hours) 1
• Patients should be nursed in areas where staff are experienced in HHS management 4
• Diabetes specialist team should be involved as soon as possible 4