Pertinent Positives for HHS
The key pertinent positives for hyperosmolar hyperglycemic state (HHS) include severe hyperglycemia (≥600 mg/dL), marked hyperosmolality (≥320 mOsm/kg), profound dehydration, altered mental status (stupor/coma), and minimal to absent ketones. 1
Laboratory Findings
Diagnostic Laboratory Criteria:
- Plasma glucose ≥600 mg/dL (can exceed 2000 mg/dL in extreme cases) 1, 2
- Effective serum osmolality ≥320 mOsm/kg (calculated as: 2[measured Na (mEq/L)] + glucose (mg/dL)/18) 1
- Arterial pH >7.30 (distinguishes from DKA) 1
- Serum bicarbonate >15 mEq/L 1
- Small or absent urine/serum ketones (nitroprusside method) 1
- Variable anion gap (typically not elevated like in DKA) 1
- Elevated BUN/creatinine (reflecting severe dehydration and prerenal azotemia) 3
- Corrected serum sodium often elevated (add 1.6 mEq for each 100 mg/dL glucose >100 mg/dL) 3, 4
Clinical Presentation
Mental Status Changes:
- Stupor to coma is the hallmark (more frequent in HHS than DKA) 1, 4
- Mental status varies from profound lethargy to complete coma 1, 4
- Severity correlates directly with degree of hyperosmolality 5, 6
Signs of Severe Dehydration:
- Poor skin turgor 4
- Tachycardia 4
- Hypotension or shock 1, 4
- Marked volume depletion (typical total water deficit ~9 L) 4
Temperature Abnormalities:
- Patients can be normothermic or even hypothermic despite infection being present 1, 3
- Hypothermia is a poor prognostic sign 1
Patient Demographics and Risk Factors
High-Risk Population:
- Elderly patients with type 2 diabetes (particularly nursing home residents) 1, 3, 7
- Patients unable to access fluids or unaware of hyperglycemia 1, 3
- Age is the best known prognostic indicator 7
Common Precipitating Factors to Identify
Most Common Trigger:
Other Precipitants:
- Cerebrovascular accident 1, 3
- Myocardial infarction 1, 3
- Pancreatitis 1, 3
- Medications: corticosteroids, thiazides, sympathomimetics (dobutamine, terbutaline) 1, 3
Critical Pitfalls to Avoid
Do not assume infection is present based on fever alone - patients may be normothermic or hypothermic despite serious infection due to peripheral vasodilation 1, 3. Always obtain cultures if infection is suspected.
Do not confuse with DKA - the key differentiator is minimal/absent ketones and lack of significant acidosis (pH >7.30, bicarbonate >15 mEq/L) despite extreme hyperglycemia 1, 6.
Watch for atypical presentations in elderly - older patients often have very atypical signs and symptoms 8. Dysphagia may indicate osmotic demyelination syndrome as a complication 9.
Initial Workup Required
Essential Laboratory Tests: 1, 3
- Plasma glucose
- BUN/creatinine
- Serum ketones
- Electrolytes with calculated anion gap
- Osmolality
- Arterial blood gases
- Complete blood count with differential
- Urinalysis with urine ketones by dipstick
- Electrocardiogram
- HbA1c (to determine if acute vs. chronic poor control)
- Chest X-ray if indicated
- Bacterial cultures if infection suspected