From the Guidelines
Laboratory diagnosis of Hyperosmolar Hyperglycemic State (HHS) is confirmed by blood glucose levels exceeding 600 mg/dL, elevated serum osmolality above 320 mOsm/kg, minimal or absent ketosis, arterial pH greater than 7.30, and serum bicarbonate above 18 mEq/L, as stated in the most recent study 1.
Key Diagnostic Criteria
- Blood glucose: exceeds 600 mg/dL
- Serum osmolality: elevated above 320 mOsm/kg
- Ketosis: minimal or absent
- Arterial pH: greater than 7.30
- Serum bicarbonate: above 18 mEq/L
Additional Laboratory Findings
- Blood urea nitrogen and creatinine: elevated due to dehydration
- Serum sodium: may be falsely low due to hyperglycemia
- Potassium levels: can be normal, high, or low despite total body potassium depletion
- Complete blood count: often shows elevated hemoglobin and hematocrit from hemoconcentration
- Urinalysis: typically shows glycosuria with minimal or no ketonuria
Calculation of Effective Serum Osmolality
Effective serum osmolality can be calculated using the formula: 2[measured Na (mEq/l)] + glucose (mg/dl)/18, as mentioned in 1.
Clinical Presentation
Clinical presentation of severe hyperglycemia, hyperosmolality, and dehydration without significant acidosis confirms the diagnosis of HHS, as stated in 1.
From the Research
Lab Diagnosis of Hyperosmolar Hyperglycemic State (HHS)
- The diagnosis of HHS is based on the presence of marked hyperglycemia (≥30 mmol/L), hyperosmolarity (≥320 mOsm/kg), and the absence of significant ketonaemia (≤3.0 mmol/L) and acidosis (pH >7.3) 2, 3, 4.
- The calculation of osmolality is crucial and can be done using the formula: [(2×Na+) + glucose + urea] 2.
- Laboratory findings also include elevated serum glucose, minimal or absent ketones, and a neurologic abnormality, most commonly altered mental status 3, 5, 6.
- The diagnosis of HHS should be considered in patients with type 2 diabetes mellitus, especially in the presence of underlying infections, certain medications, nonadherence to therapy, undiagnosed diabetes mellitus, substance abuse, and coexisting disease 5, 6.
Key Laboratory Parameters
- Serum osmolality ≥320 mOsm/kg 2, 4
- Blood glucose ≥30 mmol/L 2
- Ketonaemia ≤3.0 mmol/L 2
- pH >7.3 2
- Bicarbonate ≥15 mmol/L 2
- Electrolyte abnormalities, particularly potassium levels 2, 5, 6
Treatment and Management
- Treatment involves fluid resuscitation, correction of electrolyte abnormalities, and insulin therapy 2, 3, 5, 6, 4.
- The goals of therapy are to improve clinical status, replace fluid losses, gradual decline in osmolality, and prevent hypoglycemia and hypokalemia 2.
- Identification and treatment of underlying and precipitating causes are necessary to prevent future episodes 5, 6.