Diagnostic Criteria and Management of Hyperosmolar Hyperglycemic State (HHS)

Core Diagnostic Parameters

The American Diabetes Association establishes that HHS is diagnosed when plasma glucose is ≥600 mg/dL, arterial pH is >7.30, serum bicarbonate is ≥15 mEq/L, effective serum osmolality is ≥320 mOsm/kg, and ketones are absent or minimal, typically accompanied by altered mental status 1, 2, 3, 4, 5
Plasma glucose levels should be ≥600 mg/dL for HHS diagnosis, as recommended by the American Diabetes Association 1, 2, 3, 4, 5
Arterial pH should be >7.30 to distinguish HHS from diabetic ketoacidosis (DKA), according to the American Diabetes Association 1, 2, 3, 4, 5
Serum bicarbonate levels should be ≥15 mEq/L for HHS diagnosis, as established by the American Diabetes Association 1, 2, 3, 4, 5
Effective serum osmolality should be ≥320 mOsm/kg, calculated using the formula: 2[measured Na (mEq/L)] + glucose (mg/dL)/18, as recommended by the American Diabetes Association 1, 2, 4, 6

Urine ketones should be small (by nitroprusside reaction method) to confirm HHS diagnosis, as noted by the American Diabetes Association 3, 5
Serum ketones should be small to distinguish HHS from DKA, according to the American Diabetes Association 3, 5

Mental status in HHS patients ranges from stupor to coma, which is more common than in DKA, as reported by the American Diabetes Association 3, 5
Altered sensorium correlates with the degree of hyperosmolality in HHS patients, as noted by the American Diabetes Association 3, 5

Corrected serum sodium must be calculated to accurately assess true sodium status, as hyperglycemia causes pseudohyponatremia, according to the American Diabetes Association 6
Add 1.6 mEq to measured sodium for each 100 mg/dL glucose above 100 mg/dL to calculate corrected serum sodium, as recommended by the American Diabetes Association 1, 2, 4, 6

HHS differs from DKA in terms of evolution, dehydration, acidosis, and ketone status, as noted by the American Diabetes Association 3, 5
HHS develops over days to weeks, whereas DKA develops over hours, according to the American Diabetes Association 5
Acidosis is absent or minimal in HHS (pH >7.30), whereas it is significant in DKA (pH <7.30), as reported by the American Diabetes Association 3, 5

The American Diabetes Association recommends obtaining arterial blood gases, complete blood count with differential, comprehensive metabolic panel, urinalysis with ketones by dipstick, serum ketones, and electrocardiogram immediately after establishing clinical suspicion of HHS 1, 2, 3, 4
Cultures (blood, urine, throat) should be obtained if infection is suspected, as recommended by the American Diabetes Association 1, 2, 4

Hypothermia, if present, is a poor prognostic sign in HHS patients, despite infection being a common precipitant, as noted by the American Diabetes Association 3, 5
Patients may be normothermic or hypothermic due to peripheral vasodilation, according to the American Diabetes Association 3, 5