From the Guidelines
Diagnosing Hyperosmolar Hyperglycemic State (HHS) requires identifying severe hyperglycemia, hyperosmolality, and significant dehydration without significant ketoacidosis, with a blood glucose typically >600 mg/dL and serum osmolality >320 mOsm/kg. The diagnosis of HHS is established based on specific clinical and laboratory findings, including impaired mental status and elevated plasma osmolality in a patient with hyperglycemia 1. Initial evaluation should include a comprehensive metabolic panel to assess glucose levels, electrolytes, renal function, and calculation of serum osmolality.
Key Diagnostic Criteria
- Severe hyperglycemia (blood glucose >600 mg/dL)
- Hyperosmolality (serum osmolality >320 mOsm/kg)
- Significant dehydration
- Minimal or absent ketones
- Impaired mental status Arterial blood gas analysis should be performed to rule out significant acidosis (pH is usually >7.30 in HHS) 1. Urinalysis should check for glucose and minimal or absent ketones, which helps differentiate HHS from diabetic ketoacidosis. Additional tests should include complete blood count, HbA1c, and assessment for precipitating factors such as infection (blood cultures, chest X-ray, urinalysis). Mental status changes are common in HHS due to hyperosmolality, so neurological assessment is essential.
Diagnostic Approach
- Comprehensive metabolic panel
- Arterial blood gas analysis
- Urinalysis
- Complete blood count
- HbA1c
- Assessment for precipitating factors The diagnosis requires excluding other causes of altered mental status and recognizing that HHS typically develops gradually over days to weeks, often in elderly patients with type 2 diabetes or undiagnosed diabetes. Prompt diagnosis is crucial as HHS carries a higher mortality rate than diabetic ketoacidosis, primarily due to the severe dehydration and associated complications 1.
From the Research
Diagnosis of Hyperosmolar Hyperglycemic State (HHS)
To diagnose HHS, the following criteria should be met:
- Elevated glucose levels 2, 3, 4, 5, 6
- Elevated serum osmolality, with a value of ≥320 mOsm/kg using [(2×Na+ ) + glucose+urea] 5
- Minimal or absent ketones, with a level of ≤3.0 mmol/L 5
- Neurologic abnormality, most commonly altered mental status, ranging from lethargy to coma 2, 3, 4
- Marked hypovolaemia and hyperglycaemia ≥30 mmol/L 5
Key Diagnostic Features
Some key features to look out for in diagnosing HHS include:
- Profound dehydration 2, 4
- Neurologic symptoms, such as altered mental status, lethargy, or coma 2, 3, 4
- Absence of significant ketosis or acidosis 3, 5
- Elevated serum osmolality and glucose levels 2, 3, 4, 5, 6
Laboratory Tests
Laboratory tests that can aid in the diagnosis of HHS include: