From the Guidelines
Hyperosmolar hyperglycemic state (HHS) is diagnosed through a combination of clinical assessment and laboratory findings, requiring severe hyperglycemia (blood glucose typically >600 mg/dL), significant hyperosmolality (serum osmolality >320 mOsm/kg), and absence of significant ketoacidosis, as outlined in the most recent guidelines 1. The diagnosis of HHS is critical as it carries a higher mortality rate than diabetic ketoacidosis (DKA), and prompt identification allows for immediate fluid resuscitation, insulin therapy, electrolyte correction, and management of underlying precipitating factors. Key diagnostic criteria for HHS include:
- Severe hyperglycemia (blood glucose >600 mg/dL)
- Significant hyperosmolality (serum osmolality >320 mOsm/kg)
- Absence of significant ketoacidosis
- Impaired mental status
- Elevated plasma osmolality Initial evaluation should include:
- Comprehensive metabolic panel to assess glucose levels, electrolytes, renal function, and calculation of serum osmolality
- Arterial blood gas analysis to differentiate HHS from DKA
- Urinalysis to check for glucose, ketones, and signs of infection
- Complete blood count to assess for infection
- Cardiac enzymes if cardiac ischemia is suspected
- Appropriate cultures if infection is a potential trigger
- Imaging studies to identify precipitating factors such as stroke, myocardial infarction, or infection, as recommended in previous studies 1.
From the Research
Diagnostic Criteria for HHS
The diagnostic criteria for Hyperosmolar Hyperglycemic State (HHS) include:
- Plasma glucose level >600 mg/dL 2
- Increased effective plasma osmolality >320 mOsm/kg 3, 2
- Absence of ketoacidosis 4, 3, 5
- Severe dehydration and hyperosmolarity 4, 6, 5
- Minimal to no presence of ketones 3, 5
- Lack of metabolic acidosis 3, 5
Clinical Features of HHS
The clinical features of HHS include:
- Marked hypovolaemia 3
- Osmolality ≥320 mOsm/kg 3
- Marked hyperglycaemia ≥30 mmol/L 3
- Without significant ketonaemia (≤3.0 mmol/L) 3
- Without significant acidosis (pH >7.3) and bicarbonate ≥15 mmol/L 3
- Profound dehydration and neurologic symptoms ranging from lethargy to coma 6
Laboratory Tests for HHS
The laboratory tests for HHS include:
- Glucose levels 4, 3, 6
- Sodium levels 6
- Potassium levels 6
- Osmolality levels 3, 2
- Ketone levels 3, 5
- Arterial blood gas to assess for acidosis 3
Underlying Causes of HHS
The underlying causes of HHS include: