What is the immediate treatment for a patient presenting with hyperglycemic hyperosmolar state?

Immediate Treatment for Hyperglycemic Hyperosmolar State

Begin aggressive fluid resuscitation with isotonic saline (0.9% NaCl) at 15-20 ml/kg/h during the first hour, and critically, delay insulin administration until blood glucose stops falling with fluids alone unless significant ketonaemia is present. 1, 2, 3

Initial Assessment and Monitoring (0-60 minutes)

Obtain immediate laboratory studies including arterial blood gases, complete blood count, urinalysis, blood glucose, BUN, creatinine, electrolytes, and calculate effective serum osmolality using the formula: 2[measured Na (mEq/l)] + glucose (mg/dl)/18. 1, 4 Target osmolality is ≥320 mOsm/kg, glucose ≥30 mmol/L (≥540 mg/dL), pH >7.3, bicarbonate ≥15 mmol/L, and ketones ≤3.0 mmol/L to confirm HHS rather than DKA. 3

Calculate corrected serum sodium by adding 1.6 mEq for each 100 mg/dl glucose above 100 mg/dl—this is essential for proper fluid selection and an initial rise in sodium is expected and normal. 1, 4, 5

Fluid Resuscitation Strategy

First Hour (Phase 1)

• Administer isotonic saline (0.9% NaCl) at 15-20 ml/kg/h to restore intravascular volume and renal perfusion, recognizing that HHS patients have profound dehydration with average total water deficits of approximately 9 liters (100-220 ml/kg). 1, 2, 3

After First Hour (Phases 2-5)

• If corrected serum sodium is normal or elevated, transition to 0.45% NaCl (half-normal saline) at 4-14 ml/kg/h. 1, 2, 4
• If corrected serum sodium is low, continue 0.9% NaCl at 4-14 ml/kg/h. 1, 4
• Aim to correct estimated fluid deficits within 24-48 hours with careful hemodynamic monitoring through blood pressure improvement, urine output (target ≥0.5 ml/kg/h), and clinical examination. 2, 3

Critical Monitoring Parameter

Monitor serum osmolality every 2-4 hours and ensure the induced change does not exceed 3-8 mOsm/kg/h—rapid osmolality correction can precipitate devastating neurological complications including central pontine myelinolysis and cerebral edema. 2, 5, 3 This is the single most important safety parameter distinguishing HHS management from DKA.

Insulin Administration: The Key Difference

Withhold insulin until blood glucose stops falling with IV fluids alone (unless significant ketonaemia is present), as fluid replacement alone will cause substantial glucose reduction and early insulin use may be detrimental. 5, 3 This represents a fundamental departure from DKA management and reflects the pathophysiology of HHS where severe dehydration, not insulin deficiency, is the primary driver of hyperglycemia.

When insulin is eventually required:

• Start fixed rate intravenous insulin infusion (FRIII) at 0.1 U/kg/h after the glucose plateau is reached with fluids. 3, 6
• Add 5-10% dextrose to IV fluids once glucose falls below 14-15 mmol/L (250-270 mg/dL) and reduce insulin to 0.05-0.1 U/kg/h. 4, 3
• Target glucose of 10-15 mmol/L (180-270 mg/dL) in the first 24 hours, not normoglycemia. 3

Electrolyte Management

Once renal function is confirmed and serum potassium is known, add 20-30 mEq/L potassium (2/3 KCl and 1/3 KPO4) to IV fluids. 1, 2, 4 Do not add potassium if levels are elevated, but if potassium is low, immediate correction is required before any insulin therapy as insulin will drive potassium intracellularly and precipitate life-threatening hypokalemia. 2

Level of Care and Specialist Involvement

Admit to intensive care unit for continuous monitoring, as HHS has higher mortality than DKA and patients are at risk for myocardial infarction, stroke, seizures, vascular occlusions (mesenteric artery occlusion, disseminated intravascular coagulopathy), and rhabdomyolysis. 1, 5, 7

Involve the diabetes specialist team immediately and ensure nursing staff experienced in HHS management are assigned. 5, 3

Identify and Treat Precipitating Causes

Obtain cultures (blood, urine, throat) and chest X-ray as underlying infection is the most common precipitant, followed by myocardial infarction, stroke, medications, non-compliance, and coexisting diseases. 1, 3, 6 Appropriate antibiotics should be initiated if infection is suspected.

Common Pitfalls to Avoid

• Do not use hypotonic fluids initially despite elevated sodium—the corrected sodium accounts for hyperglycemia and an initial rise in measured sodium is expected and appropriate. 5
• Do not start insulin before adequate fluid resuscitation—this is associated with worse outcomes in HHS. 5, 3
• Do not correct osmolality too rapidly (>8 mOsm/kg/h)—this risks osmotic demyelination syndrome. 5, 3
• Do not overlook cardiac or renal compromise—these patients may require central venous pressure monitoring and more cautious fluid administration to prevent pulmonary edema. 4

Resolution Criteria

Treatment goals are met when: osmolality <300 mOsm/kg, hypovolaemia corrected with urine output ≥0.5 ml/kg/h, cognitive status returned to baseline, and blood glucose <15 mmol/L (270 mg/dL). 3