From the Guidelines
The diagnostic criteria for Hyperosmolar Hyperglycemic State (HHS) include plasma glucose >600 mg/dL, serum osmolality >320 mOsm/kg, profound dehydration, absence of significant ketosis, and altered mental status ranging from confusion to coma, as stated in the most recent and highest quality study 1.
Key Diagnostic Criteria
- Plasma glucose >600 mg/dL (33.3 mmol/L)
- Serum osmolality >320 mOsm/kg
- Profound dehydration
- Absence of significant ketosis
- Altered mental status ranging from confusion to coma
Additional Criteria
- Arterial pH >7.30
- Serum bicarbonate >15 mEq/L
- Minimal ketonuria and ketonemia
Clinical Presentation
Patients with HHS typically present with severe hyperglycemia, hyperosmolality, and dehydration without significant acidosis, as noted in 1. Laboratory findings often reveal high blood urea nitrogen (BUN) and creatinine levels reflecting prerenal azotemia, with variable electrolyte abnormalities including hyponatremia or hypernatremia.
Pathophysiology
HHS develops gradually over days to weeks, with patients experiencing polyuria, polydipsia, and progressive dehydration that can reach 8-12 liters, as described in 1. The absence of significant ketosis in HHS (unlike diabetic ketoacidosis) occurs because residual insulin activity prevents lipolysis while being insufficient to control hyperglycemia.
Importance of Prompt Recognition
Prompt recognition of these criteria is essential as HHS carries a higher mortality rate than diabetic ketoacidosis, particularly in elderly patients with comorbidities, as highlighted in 1. Mental status changes correlate with the degree of hyperosmolality and typically become clinically apparent when serum osmolality exceeds 320-330 mOsm/kg.
From the Research
Diagnostic Criteria for Hyperosmolar Hyperglycemic State (HHS)
The diagnostic criteria for HHS include:
- Elevated glucose levels, typically above 600 mg/dl 2, 3
- Elevated serum osmolality, typically above 320 mOsm/kg 4, 2, 3
- Minimal or absent ketones 5, 2
- Neurologic abnormalities, such as altered mental status, lethargy, or coma 5, 2
- Plasma glucose > 600 mg/dl, venous pH > 7.25, sodium bicarbonate > 15 mmol/l, slight ketonuria, and impairment of consciousness (aggression, unconsciousness, convulsions) 3
Key Laboratory Values
Key laboratory values to monitor in HHS include:
- Glucose levels 5, 4, 2
- Serum osmolality 4, 2
- Sodium levels 4, 2
- Potassium levels 2
- Venous pH and bicarbonate levels 3
Clinical Presentation
The clinical presentation of HHS may include: