Lactated Ringer's Solution is Preferred Over Normal Saline for Septic Shock
Based on the most recent 2025 guidelines, Lactated Ringer's (LR) or other balanced crystalloid solutions should be used instead of normal saline (NS) for fluid resuscitation in septic shock. 1
Guideline Recommendations
The Surviving Sepsis Campaign explicitly recommends using balanced crystalloids instead of normal saline for resuscitation in patients with sepsis or septic shock. 1 This represents a shift from earlier 2013 guidelines that simply recommended "crystalloids" without specifying type. 1
The recommendation for balanced crystalloids applies to the standard 30 mL/kg initial fluid bolus given within the first 3 hours. 1
Why Balanced Crystalloids Are Superior
Metabolic Advantages
- LR avoids hyperchloremic metabolic acidosis that occurs with NS due to its supraphysiologic chloride content (154 mmol/L vs. physiologic ~100 mmol/L). 2
- NS causes renal vasoconstriction, increased cytokine secretion, and higher risk of acute kidney injury. 1
- LR contains near-physiological electrolyte concentrations with lactate as a buffer. 2
Clinical Outcomes Evidence
- Large-scale trials (SMART and SALT) demonstrated that balanced crystalloids result in lower rates of major adverse kidney events compared to saline in critically ill patients (n=15,802). 2
- The SALT trial specifically showed lower 30-day in-hospital mortality and reduced need for renal replacement therapy with balanced crystalloids. 2
- A retrospective study of 198 septic shock patients found LR required less total fluid volume and fewer blood products compared to NS, with lower incidences of hyperlactacidemia (71.4% vs 86.0%) and hyperchloremia (13.2% vs 25.0%). 3
Important Caveats
Traumatic Brain Injury Exception
If the patient has traumatic brain injury, use normal saline rather than LR. 2 This is the primary contraindication to balanced crystalloid use.
Lactate Monitoring Consideration
- LR administration can modestly increase serum lactate levels (mean increase 0.93 mmol/L in healthy volunteers), though this is not associated with acidosis. 4
- This elevation should not be misinterpreted as worsening tissue hypoperfusion when trending lactate clearance. 5
Pregnancy-Specific Guidance
In pregnant patients with septic shock, the same preference for balanced crystalloids applies, though some obstetric societies recommend more cautious initial fluid volumes (1-2L bolus initially, escalating to 30 mL/kg if needed) due to lower colloid oncotic pressure and higher pulmonary edema risk. 1
Practical Implementation
- Start with LR or another balanced crystalloid solution (e.g., Plasma-Lyte) for the initial 30 mL/kg bolus. 1, 2
- If NS must be used in specific circumstances, limit to 1-1.5 L maximum to minimize adverse effects. 2
- Continue balanced crystalloids for ongoing resuscitation needs beyond the initial bolus. 1
- Monitor for volume overload in patients with heart failure or chronic kidney disease during aggressive fluid resuscitation. 6