What is the management of Hyperosmolar Hyperglycemic State (HHS)?

Management of Hyperosmolar Hyperglycemic State (HHS)

The management of HHS requires aggressive fluid resuscitation as the primary initial intervention, followed by careful insulin administration, electrolyte replacement, and identification and treatment of precipitating factors. 1

Diagnostic Criteria

HHS is characterized by:

• Plasma glucose ≥600 mg/dL
• Effective serum osmolality ≥320 mOsm/kg H₂O (calculated as 2[measured Na⁺] + glucose/18)
• Arterial pH >7.3
• Serum bicarbonate >15 mEq/L
• Minimal or absent ketones in urine or serum
• Altered mental status (stupor/coma) 1

Treatment Algorithm

1. Initial Assessment and Monitoring (0-60 minutes)

• Obtain arterial blood gases, complete blood count, urinalysis, blood glucose, BUN, electrolytes, and creatinine 2
• Monitor vital signs, mental status, fluid intake/output, electrolytes, glucose, and calculate osmolality regularly 1
• Calculate effective serum osmolality: 2[measured Na⁺ (mEq/L)] + glucose (mg/dL)/18 1

2. Fluid Resuscitation

• Begin with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour during the first hour 1
• Fluid replacement alone will cause a fall in blood glucose level 3
• Total body water deficit is typically 100-220 mL/kg (9L average in adults) 4, 5
• After initial stabilization, adjust fluid type based on corrected sodium:
  • If corrected sodium is normal or elevated: 0.45% NaCl at 4-14 mL/kg/hour
  • If corrected sodium is low: continue 0.9% NaCl 2
• Aim to correct estimated fluid deficit within 24 hours 1
• Target osmolality reduction: 3-8 mOsm/kg/hour to prevent neurological complications 1, 4

3. Insulin Therapy

• Withhold insulin until blood glucose is no longer falling with IV fluids alone, unless ketonaemia is present 3, 4
• When initiating insulin:
  • Administer 0.15 U/kg IV bolus, followed by continuous infusion at 0.1 U/kg/hour 1
  • Adjust to achieve glucose decrease of 50-75 mg/dL/hour 1
  • Add 5% or 10% glucose infusion once blood glucose falls below 250-300 mg/dL to prevent hypoglycemia 4, 5
• Monitor closely for hypoglycemia, which is the most common adverse reaction of insulin therapy 6

4. Electrolyte Management

• Potassium:
  • Add potassium to IV fluids once renal function is confirmed and serum potassium is known 1
  • Administer 20-30 mEq/L (2/3 KCl and 1/3 KPO₄) 1
  • Monitor closely as insulin therapy can cause hypokalemia 6
• Monitor and replace magnesium, calcium, and phosphate as needed 1

5. Identify and Treat Precipitating Factors

• Common precipitants include infections, medications (diuretics, corticosteroids, beta-blockers), non-adherence to diabetes therapy, undiagnosed diabetes, and substance abuse 5
• Obtain appropriate cultures and initiate antibiotics if infection is suspected 2

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, 4

Complications and Prevention

Potential Complications

• Cerebral edema and central pontine myelinolysis (from rapid osmolality changes) 3
• Hypoglycemia and hypokalemia (from insulin therapy) 6
• Thromboembolism (due to hyperviscosity) 1
• Multiorgan failure: renal failure, respiratory distress, rhabdomyolysis, heart failure 7

Prevention Strategies

• Patient education on diabetes management during illness 1
• Never suspending insulin during illnesses
• Regular glucose monitoring, especially during illness or stress
• Early medical attention when symptoms develop 1

Special Considerations

• Elderly patients and those with cardiac or renal disease require more cautious fluid management 1
• Mixed DKA/HHS presentations require modified approach with earlier insulin initiation 4
• In children and adolescents, correct dehydration at a rate of no more than 3 mOsm/hour to avoid cerebral edema 5, 7

HHS has a higher mortality rate than DKA and requires careful monitoring throughout treatment to prevent complications and ensure successful resolution of this life-threatening condition.