What is the preferred choice between Normal Saline (NS) and Ringer's Lactate (RL) for fluid resuscitation in Diabetic Ketoacidosis (DKA)?

Fluid Resuscitation in Diabetic Ketoacidosis: Normal Saline vs. Ringer's Lactate

Balanced crystalloids such as Ringer's Lactate are preferred over Normal Saline for fluid resuscitation in DKA due to faster resolution of acidosis and DKA. 1, 2

Initial Fluid Management

First Hour of Resuscitation

• Begin with isotonic saline (0.9% NaCl) at 15-20 ml/kg/hour for the first hour 3
• For pediatric patients: 0.9% NaCl at 10-20 ml/kg/hour (not exceeding 50 ml/kg in first 4 hours) 3

Subsequent Fluid Management

• After initial resuscitation, transition to balanced crystalloids (Ringer's Lactate) 3, 1
• Fluid rate after first hour: 4-14 ml/kg/hour based on hydration status 4
• Adjust fluid choice based on corrected serum sodium:
  • If corrected sodium normal/elevated: 0.45% NaCl at 4-14 ml/kg/hour
  • If corrected sodium low: continue 0.9% NaCl at 4-14 ml/kg/hour 4, 3

Evidence Supporting Balanced Crystalloids

Clinical Advantages

• Balanced fluids (Ringer's Lactate) result in:
  • Faster DKA resolution by approximately 5.36 hours 1
  • More rapid correction of pH 5
  • Lower post-resuscitation chloride levels (4.26 mmol/L lower) 1
  • Higher post-resuscitation bicarbonate levels (1.82 mmol/L higher) 1
  • Reduced risk of hyperchloremic metabolic acidosis 2

Recent Evidence

• A 2024 meta-analysis of 10 studies (1006 participants) demonstrated that balanced electrolyte solutions resolve DKA faster than normal saline 1
• A 2024 multicenter study found lactated Ringer's associated with faster resolution of high anion gap metabolic acidosis compared to normal saline (adjusted HR 1.325; 95% CI 1.121-1.566) 2
• A 2025 retrospective cohort study showed balanced fluids resulted in faster DKA resolution compared to normal saline (13 vs. 17 hours, p=0.02) 6

Monitoring and Adjustments

Electrolyte Management

• Add potassium (20-30 mEq/L) once renal function is confirmed (2/3 KCl and 1/3 KPO₄) 4, 3
• When glucose reaches 250-300 mg/dL, switch to 5% dextrose with 0.45% NaCl 3

Monitoring Parameters

• Monitor vital signs hourly (HR, BP, RR, mental status) 3
• Check electrolytes, BUN, creatinine, and venous pH every 2-4 hours initially 3
• Ensure serum osmolality changes do not exceed 3 mOsm/kg/hour 4, 3
• Correct estimated fluid deficits within 24 hours 4

Special Considerations

Renal and Cardiac Compromise

• More frequent monitoring of serum osmolality and continuous evaluation of cardiac, renal, and mental status 4
• Avoid fluid overload in patients with renal or cardiac dysfunction 4

Pediatric Patients

• Initial fluid therapy with isotonic saline at 10-20 ml/kg/hour 4
• Do not exceed 50 ml/kg in first 4 hours 4
• Continue fluid therapy to replace deficit evenly over 48 hours 4

Pitfalls to Avoid

1. Overreliance on normal saline: While traditionally recommended, normal saline can worsen acidosis due to hyperchloremic metabolic acidosis 3, 1

2. Rapid fluid administration: Too rapid correction of osmolality (>3 mOsm/kg/hour) increases risk of cerebral edema, particularly in pediatric patients 4, 3

3. Inadequate potassium replacement: Ensure potassium is added once renal function is confirmed to prevent hypokalemia during treatment 4, 3

4. Failure to transition fluids: Not switching to dextrose-containing fluids when glucose reaches 250-300 mg/dL can lead to hypoglycemia 3

5. Inadequate monitoring: Failure to regularly assess electrolytes, acid-base status, and clinical response may lead to complications 3