Hyperglycemic Hyperosmolar Non-Ketotic Syndrome (HHNS)

Introduction

• Hyperglycemic hyperosmolar non-ketotic syndrome (HHNS) is a life-threatening complication of diabetes mellitus.
• Similar to diabetic ketoacidosis (DKA) but characterized by extreme hyperglycemia.
• Blood sugar levels can exceed 600 mg/dL, sometimes reaching four digits.
• Causes blood to become highly concentrated (hyperosmolarity).
• No ketone production due to the presence of some insulin.

Key Characteristics

• Hyperglycemia: Blood sugar levels significantly higher than in DKA.
• Hyperosmolarity: High concentration of glucose in the blood.
• Dehydration: Caused by osmotic diuresis.
• Primarily occurs in type 2 diabetics but can occur in type 1 (rare).

Pathophysiology

• Glucose: Cells are resistant to insulin, leading to high glucose concentration in the blood.
• Insulin: Present but not effectively utilized by cells, preventing fat breakdown.
• Kidneys: Fail to reabsorb excess glucose, leading to glucose in urine and osmotic diuresis.
• Electrolyte imbalance: Loss of electrolytes like sodium, potassium, and chloride due to excessive urination.

Causes

• Primarily triggered by illness or infection, especially in older adults.
• Gradual onset compared to the sudden onset of DKA.
• Typical signs include unmanageable high blood sugar, polyuria, and polydipsia.

Clinical Signs

• Severe hyperglycemia (possible four-digit readings).
• Polyuria due to glucose leakage into urine.
• Polydipsia due to excessive urination.
• Dehydration: Dry mucous membranes, fever, fatigue.
• Mental status changes: Confusion, possible progression to coma or seizures.

Nursing Interventions

• Hydration: Administer IV fluids to reduce blood sugar and correct dehydration.

  • Use isotonic solutions initially (e.g., 0.9% saline).
  • Transition to hypotonic solutions (e.g., half normal saline) to rehydrate cells.
  • Monitor for cerebral edema when using hypotonic solutions.

• Insulin Therapy: Manage blood glucose levels.

  • Start with an insulin bolus followed by a drip (regular insulin only).
  • Ensure potassium levels are above 3.3 mEq/L to prevent hypokalemia due to insulin pushing potassium into cells.

• Electrolyte Management:

  • Monitor and administer potassium solutions to maintain normal levels.
  • Watch for irritation (phlebitis), EKG changes, and renal function.

• Insulin Administration Tips:

  • Prime IV tubing to avoid insulin absorption into the plastic lining.

Conclusion

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