Hyperosmolar Hyperglycaemic Syndrome Management

Initial Assessment and Diagnosis

HHS is diagnosed by blood glucose >600 mg/dl, arterial pH >7.3, bicarbonate >15 mEq/l, mild ketonuria or ketonemia, and effective serum osmolality >320 mOsm/kg H₂O 1
Calculate effective serum osmolality using the formula: 2[measured Na (mEq/l)] + glucose (mg/dl)/18 1
Obtain arterial blood gases, complete blood count, urinalysis, blood glucose, BUN, electrolytes, chemistry profile, and creatinine levels immediately 3
Assess for precipitating factors including infection, myocardial infarction, stroke, medications (diuretics, corticosteroids, beta-blockers), and other acute illnesses 4

Begin with isotonic saline (0.9% NaCl) at 15-20 ml/kg/h (1-1.5 L in average adult) during the first hour to expand intravascular volume and restore renal perfusion 1
After initial resuscitation, adjust fluid choice based on corrected serum sodium and hemodynamic status 3
Target fluid replacement should correct estimated deficits within the first 24 hours 3

Once insulin is started, administer as continuous intravenous infusion at 0.1 U/kg/h (typically 5-10 units/hour) 4
When plasma glucose reaches 300 mg/dl, decrease insulin infusion to 0.05-0.1 U/kg/h (3-6 U/h) 2
Add 5-10% dextrose to IV fluids when glucose falls below 300 mg/dl to prevent hypoglycemia while continuing to treat hyperosmolarity 2
Target glucose level between 250-300 mg/dl until hyperosmolarity resolves 2

Once renal function is assured and serum potassium is known, add 20-30 mEq/L potassium (2/3 KCl and 1/3 KPO₄) to the infusion 3
Monitor electrolytes (sodium, potassium, chloride, bicarbonate, phosphate, magnesium) every 2-4 hours during initial treatment 1
Correct electrolyte imbalances based on laboratory results 4

Monitor vital signs, mental status, fluid input/output, and hemodynamic parameters hourly 3
Check blood glucose every 1-2 hours until stable 4
Calculate effective serum osmolality regularly to guide fluid management 2
Monitor for complications including cerebral edema, myocardial infarction, stroke, and vascular thrombosis 4

Successful transition from intravenous to subcutaneous insulin requires administration of basal insulin 2-4 hours before the intravenous insulin is stopped 4
Consider low-dose basal insulin analog in addition to intravenous insulin infusion to prevent rebound hyperglycemia 4

Elderly patients and those with cardiac/renal compromise require more cautious fluid rates with closer monitoring 2
Do not use bicarbonate therapy routinely, as it has not been shown to improve outcomes 4
Avoid excessive fluid administration in patients with cardiac or renal compromise 3