What is the recommended first-line crystalloid solution for fluid resuscitation?

Recommended First-Line Crystalloid Solution for Fluid Resuscitation

Balanced crystalloid solutions (such as lactated Ringer's or Plasma-Lyte) should be used as the first-line fluid for resuscitation, with 0.9% sodium chloride (normal saline) as an acceptable alternative if balanced solutions are unavailable. 1, 2

Primary Recommendation

• Initiate fluid therapy with either balanced crystalloid solutions or 0.9% sodium chloride in hypotensive patients requiring resuscitation 1
• Balanced crystalloids are increasingly preferred over normal saline to reduce the risk of hyperchloremic metabolic acidosis and potential adverse renal events 1, 2
• Administer at least 30 mL/kg of crystalloid within the first 3 hours of resuscitation in septic patients 1, 2, 3

Evidence Supporting Balanced Crystalloids

The 2023 European trauma guidelines and 2017 Surviving Sepsis Campaign both recommend crystalloids as first-line therapy, with growing preference for balanced solutions 1. The rationale centers on avoiding hyperchloremic acidosis associated with large-volume normal saline administration 1.

• In sepsis, balanced crystalloids reduce the composite outcome of death, new renal replacement therapy, or persistent renal dysfunction compared to normal saline 1
• The 2022 French guidelines for critically ill patients recommend balanced crystalloids over 0.9% NaCl specifically to reduce mortality and adverse renal events in hemorrhagic shock 1
• Balanced solutions contain physiological or near-physiological chloride concentrations, making them advantageous for large-volume resuscitation 1

When Normal Saline is Acceptable

Normal saline remains a viable alternative when balanced solutions are unavailable 1. However, important caveats apply:

• If using 0.9% sodium chloride, limit administration to a maximum of 1-1.5 L 1
• Avoid saline solutions in severe acidosis, especially when associated with hyperchloremia 1
• In trauma patients, one study showed no clinically significant difference in acid-base parameters between lactated Ringer's and normal saline 4

Special Population Considerations

Traumatic Brain Injury

• Avoid hypotonic solutions such as Ringer's lactate in patients with severe head trauma to minimize fluid shift into damaged cerebral tissue 1
• Hypertonic solutions did not improve survival or 6-month neurological outcomes in patients with traumatic brain injury 1

Hemorrhagic Shock

• Crystalloids are preferred over colloids in hemorrhagic shock due to lack of mortality benefit and risks of renal failure and hemostasis disorders with colloids 1
• Trauma patients often require high volumes (5,000-10,000 mL in first 24 hours), making the choice of balanced vs. unbalanced crystalloid particularly important 1

Fluids to Avoid

Colloids

• Restrict the use of colloids due to adverse effects on hemostasis 1
• Hydroxyethyl starches increase mortality and renal replacement therapy requirements in critically ill patients, particularly those with sepsis 1, 5
• Albumin may be considered only when patients require substantial amounts of crystalloids, but is not recommended as first-line therapy 1
• Gelatins should be avoided in favor of crystalloids 1

Administration Technique

• Use a fluid challenge technique where administration continues as long as hemodynamic factors improve 1, 2
• Monitor dynamic measures (pulse pressure variation, stroke volume variation) or static variables (arterial pressure, heart rate, mental status, urine output) 1, 2
• Stop fluid administration when no improvement in tissue perfusion occurs, signs of fluid overload develop, or hemodynamic parameters stabilize 2, 3

Common Pitfalls

• Do not delay resuscitation due to concerns about fluid overload—delayed resuscitation increases mortality 2
• Avoid relying solely on static measures like central venous pressure to guide fluid therapy, as they have poor predictive ability for fluid responsiveness 2
• In patients with chronic kidney disease, monitor carefully for fluid overload while still providing adequate initial resuscitation 3
• Excessive fluid administration during the resuscitative period is associated with increased cumulative fluid balance and adverse outcomes 5