What is the preferred fluid choice between 0.9% saline (normal saline) and Hartmann's solution for patients with Diabetic Ketoacidosis (DKA) and Hyperosmolar Hyperglycemic State (HHS)?

Fluid Choice for DKA and HHS: 0.9% Saline vs Hartmann's Solution

Use 0.9% normal saline as the initial fluid for both DKA and HHS in adults and children, as this is the standard recommended by the American Diabetes Association guidelines. 1

Initial Fluid Resuscitation Protocol

Adults

• Begin with 0.9% NaCl at 15-20 mL/kg/hour for the first hour in the absence of cardiac compromise 1
• This isotonic saline expands intravascular volume and restores renal perfusion, which are the primary goals of initial fluid therapy 1
• After the first hour, fluid choice depends on corrected serum sodium:
  • If corrected sodium is normal or elevated: switch to 0.45% NaCl at 4-14 mL/kg/hour 1
  • If corrected sodium is low: continue 0.9% NaCl at similar rate 1

Pediatric Patients

• Start with 0.9% NaCl at 10-20 mL/kg/hour for the first hour 1
• Initial reexpansion should not exceed 50 mL/kg over the first 4 hours to minimize cerebral edema risk 1

Electrolyte Supplementation

Once renal function is confirmed and serum potassium is known:

• Add 20-30 mEq/L potassium to adult fluids (2/3 KCl and 1/3 KPO4) 1
• Add 20-40 mEq/L potassium to pediatric fluids (2/3 KCl or potassium acetate and 1/3 KPO4) 2
• Potassium replacement should only begin after serum levels fall below 5.5 mEq/L 2

Evidence for Hartmann's Solution

While 0.9% saline remains the guideline-recommended standard, one pediatric randomized controlled trial (2017) found that Hartmann's solution is an acceptable alternative and may benefit those with severe DKA (pH < 7.1) 3. In this study:

• No difference in time to reach bicarbonate of 15 mmol/L between groups 3
• No difference in time to normalize pH 3
• Patients with severe DKA showed shorter recovery times with Hartmann's solution (log-rank P = 0.0277 for bicarbonate, P = 0.0024 for pH) 3
• Patients treated with Hartmann's received significantly less total fluid per kg 3

Critical Monitoring Parameters

• Monitor serum osmolality regularly and ensure the induced change does not exceed 3 mOsm/kg/hour 1
• Assess fluid status through hemodynamic monitoring, input/output measurement, and clinical examination 1
• In patients with renal or cardiac compromise, frequently assess cardiac, renal, and mental status to avoid iatrogenic fluid overload 1
• Measure serum electrolytes, glucose, BUN, creatinine, and venous pH every 2-4 hours 4

Key Differences Between DKA and HHS Management

DKA

• Insulin therapy is the cornerstone of treatment 5
• Average total water deficit: approximately 6 liters (100 mL/kg) 1

HHS

• Fluid replacement is the cornerstone of therapy 5
• Withhold insulin until blood glucose is no longer falling with IV fluids alone (unless ketonemic) 6
• Early use of insulin before adequate fluid resuscitation may be detrimental 6

Common Pitfalls to Avoid

• Do not start insulin in HHS until adequate fluid resuscitation unless significant ketonemia is present 6
• Failure to correct serum sodium for hyperglycemia (add 1.6 mEq for each 100 mg/dL glucose above 100 mg/dL) may lead to inappropriate fluid selection 4
• Excessive fluid administration in patients with cardiac or renal compromise can cause fluid overload 1
• In pediatric patients, rapid correction of hyperosmolarity increases risk of cerebral edema 5