What is the recommended first-line fluid for patients requiring fluid resuscitation or maintenance fluids, specifically using sodium chloride (NaCl) 0.9% injection?

First-Line Fluid Selection for Resuscitation and Maintenance

For patients requiring fluid resuscitation or maintenance therapy, balanced crystalloid solutions are recommended over 0.9% sodium chloride (normal saline) as first-line fluid therapy to reduce mortality and adverse renal events. 1, 2

Types of Crystalloid Solutions

Balanced Crystalloids

• Composition: Contain physiological or near-physiological concentrations of electrolytes (especially chloride)
• Examples: Lactated Ringer's, Plasmalyte, Ringer's Acetate
• Advantages:
  • Better acid-base balance 1
  • Lower risk of hyperchloremic metabolic acidosis 3
  • Potentially lower risk of acute kidney injury 2
  • May reduce transfusion requirements in high hemorrhagic risk scenarios 1

0.9% Sodium Chloride (Normal Saline)

• Composition: Contains 154 mmol/L of sodium and 154 mmol/L of chloride 1
• Disadvantages:
  • Risk of hyperchloremic metabolic acidosis with large volumes 1, 3
  • Potential increased risk of acute kidney injury 2
  • Should be limited to 1-1.5L maximum if used 1

Clinical Decision Algorithm

For Resuscitation:

1. First-line: Balanced crystalloid solution (e.g., Lactated Ringer's) 1, 2

   • Initial bolus: 20 mL/kg for adults with significant fluid deficit 1
   • Rate: 75-100 mL/hr for conservative fluid resuscitation 2

2. Second-line/Special Circumstances: 0.9% Sodium Chloride

   • When chloride loss exceeds sodium loss (e.g., pyloric obstruction) 4
   • For patients with severe traumatic brain injury (avoid hypotonic solutions) 1
   • Limit to maximum 1-1.5L to prevent hyperchloremic acidosis 1

For Maintenance:

• Balanced crystalloids at appropriate maintenance rates based on weight and clinical status 2

Special Considerations

Traumatic Brain Injury

• Avoid hypotonic solutions like Ringer's lactate 1
• 0.9% sodium chloride may be preferred to prevent cerebral edema 1

Hemorrhagic Shock

• Balanced crystalloids are preferred, especially when large volumes are needed 1
• Limit 0.9% sodium chloride to 1-1.5L maximum 1
• Avoid saline in severe acidosis, especially with hyperchloremia 1

Acute Kidney Injury

• Balanced crystalloids are preferred over 0.9% saline 2
• Monitor for fluid overload with target urine output >0.5 mL/kg/hr 2

Pediatric Patients

• Balanced crystalloids are associated with fewer electrolyte derangements compared to 0.9% NaCl 5
• Extreme hyperkalemia and acidosis are more common with 0.9% NaCl 5

Monitoring Parameters

• Electrolyte levels (sodium, potassium, chloride)
• Acid-base status
• Renal function
• Fluid balance (intake/output)
• Daily weights
• Hemodynamic parameters

Common Pitfalls to Avoid

1. Excessive fluid administration: Can lead to fluid overload, especially in patients with cardiac, renal, or hepatic dysfunction 2

2. Inappropriate use of 0.9% saline: Avoid large volumes in patients with:

   • Pre-existing acidosis 1
   • Hyperchloremia 1
   • High risk of acute kidney injury 2

3. Failure to reassess: Fluid status should be reassessed every 4-6 hours 2

4. Colloid overuse: Colloids should be restricted due to adverse effects on hemostasis and lack of proven benefit 1

5. Hypertonic saline misuse: Not recommended as first-line therapy for hemorrhagic shock resuscitation 1

By following these evidence-based recommendations, clinicians can optimize fluid management while minimizing the risks associated with inappropriate fluid selection and administration.