Hyperglycemic Hyperosmolar Non-Ketotic Syndrome (HHNS)

Overview

• HHNS is a life-threatening complication of diabetes mellitus.
• Characterized by extreme hyperglycemia and hyperosmolarity without significant ketosis.
• Blood sugar can exceed 600 mg/dL, sometimes reaching four digits.

Differences from DKA

• DKA: Presence of ketoacidosis; HHNS: No ketosis due to some insulin preventing fat breakdown.
• DKA: Variable osmolarity; HHNS: Significant hyperosmolarity leading to dehydration.
• DKA occurs in Type 1 diabetes; HHNS primarily in Type 2, though rare in Type 1.

Pathophysiology

• Glucose: Body is insulin-resistant, leading to high blood glucose levels.
• Insulin: Present but insufficient for glucose uptake, preventing fat breakdown.
• Kidneys: Unable to reabsorb high glucose levels, leading to osmotic diuresis and dehydration.

Symptoms

• Extreme hyperglycemia (unreadable by glucometer or > 600 mg/dL).
• Polyuria (frequent urination).
• Polydipsia (excessive thirst).
• Dehydration: Dry mucous membranes, fever, fatigue.
• Mental status changes: Confusion, possible coma, or seizures.

Causes

• Often triggered by illness or infection, especially in older adults.
• Develops gradually over time, unlike sudden onset in DKA.

Nursing Interventions

• Hydration and Fluid Replacement:
  • Start with isotonic solutions (0.9% saline), progress to hypotonic solutions if necessary.
  • Monitor for cerebral edema with hypotonic solutions.
• Insulin Therapy:
  • Starts with bolus followed by continuous infusion.
  • Only regular insulin is used IV.
  • Monitor potassium levels before and during insulin treatment to prevent hypokalemia.
• Electrolyte Management:
  • Potassium supplementation may be necessary.
  • Monitor for EKG changes and renal function.

Key Nursing Considerations

• Frequent monitoring of blood glucose and electrolytes.
• Titrate insulin drip based on glucose levels.
• Waste initial insulin in IV tubing due to absorption by tubing material.

Additional Resources

• Take online quizzes to test understanding of HHNS.
• Watch related videos comparing DKA and HHNS for deeper understanding.