What are the steps for testing and managing Hyperosmolar Hyperglycemic State (HHS)?

From the Guidelines

Testing and managing Hyperosmolar Hyperglycemic State (HHS) requires prompt identification and aggressive treatment, with the most recent guidelines from 2019 1 emphasizing the importance of individualized care based on careful clinical and laboratory assessment. The first step is diagnosis through laboratory tests including:

• Blood glucose (typically >600 mg/dL)
• Serum osmolality (>320 mOsm/kg)
• Absence of significant ketosis
• Assessment of renal function, electrolytes, and arterial blood gases Management begins with aggressive fluid resuscitation using isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour for the first hour, then adjusted based on hemodynamic status, as recommended by the 2018 guidelines 1. Insulin therapy should be initiated with an IV bolus of regular insulin (0.1 units/kg) followed by continuous infusion at 0.1 units/kg/hour, titrated to reduce glucose by 50-70 mg/dL/hour, with potassium replacement crucial when levels fall below 5.3 mEq/L, typically with 20-30 mEq/L of IV fluids 1. Phosphate replacement may be needed if levels are <1.0 mg/dL. Continuous monitoring of vital signs, mental status, fluid balance, electrolytes, and glucose levels every 1-2 hours is essential. The underlying cause of HHS must be identified and treated, which commonly includes infection, medication non-compliance, or new-onset diabetes. Once blood glucose reaches 250-300 mg/dL, switch to 5% dextrose with continued insulin to prevent hypoglycemia. Transition to subcutaneous insulin should occur once the patient is stable, alert, and able to eat, with successful transition requiring administration of basal insulin 2–4 h prior to the intravenous insulin being stopped to prevent recurrence of ketoacidosis and rebound hyperglycemia 1. This aggressive approach is necessary because HHS carries a mortality rate of 10-20%, primarily due to the profound dehydration, electrolyte abnormalities, and hyperosmolar state that can lead to thrombosis, cerebral edema, and multi-organ failure if not promptly corrected.

From the Research

Testing and Managing Hyperosmolar Hyperglycemic State (HHS)

• HHS is a medical emergency that requires prompt recognition and treatment, with a higher mortality rate than diabetic ketoacidosis (DKA) 2.
• The key points in managing HHS include monitoring of the response to treatment, fluid and insulin administration, and delivery of care 2.

Diagnosis of HHS

• HHS is diagnosed by an elevated glucose, elevated serum osmolality, minimal or absent ketones, and a neurologic abnormality, most commonly altered mental status 3.
• Clinical features of HHS include marked hypovolaemia, osmolality ≥320 mOsm/kg, marked hyperglycaemia ≥30 mmol/L, without significant ketonaemia (≤3.0 mmol/L), without significant acidosis (pH >7.3) and bicarbonate ≥15 mmol/L 4.

Treatment of HHS

• Treatment involves fluid resuscitation and correction of electrolyte abnormalities, with the aim of improving clinical status and replacing fluid losses within 24 hours 4.
• Intravenous (IV) 0.9% sodium chloride is used to restore circulating volume, and fixed rate intravenous insulin infusion (FRIII) should be commenced once osmolality stops falling with fluid replacement unless there is ketonaemia 4.
• Glucose infusion (5% or 10%) should be started once glucose <14 mmol/L, and potassium replacement should be done according to potassium levels 4.
• The principal goal at the outset of therapy must be restoration of the intravascular volume to assure adequate perfusion of vital organs, and correction of the syndrome will ultimately require administration of hypotonic fluids 5.

Monitoring and Resolution of HHS

• Monitoring of the response to treatment is crucial, with regular measurement of serum osmolality to monitor the response to treatment, and aiming to reduce osmolality by 3-8 mOsm/kg/h 2.
• HHS resolution criteria include osmolality <300 mOsm/kg, hypovolaemia corrected (urine output ≥0.5 ml/kg/h), cognitive status returned to pre-morbid state, and blood glucose <15 mmol/L 4.
• Early recognition and proper management of HHS are necessary for a better outcome, especially in pediatric patients where HHS is rare and potentially life-threatening 6.