What is the difference between lactate levels during infection and lactate levels after administration of sodium lactate (sodium lactate) fluid resuscitation?

From the Guidelines

Lactate levels during infection and sodium lactate fluid resuscitation serve different clinical purposes, and for sepsis resuscitation, balanced crystalloids like lactated Ringer's (typically infused at 30 ml/kg within the first 3 hours) are often preferred over normal saline due to lower risk of hyperchloremic metabolic acidosis, as recommended by the Surviving Sepsis Campaign guidelines 1.

Key Points

• Elevated serum lactate is a marker of tissue hypoperfusion and anaerobic metabolism, indicating severity of illness and poor outcomes when levels exceed 2 mmol/L.
• Serial lactate measurements help guide resuscitation efforts, with clearance suggesting improved perfusion.
• Sodium lactate solutions (such as Hartmann's or Ringer's lactate) are balanced crystalloids used for fluid resuscitation that contain physiologic electrolytes and lactate as a buffer.
• These solutions are generally safe and appropriate for most resuscitation scenarios, including sepsis, as the exogenous lactate is rapidly metabolized by the liver to bicarbonate, helping correct metabolic acidosis.
• The lactate in these fluids does not significantly affect serum lactate measurements when administered in typical volumes.

Recommendations

• For sepsis resuscitation, at least 30 mL/kg of IV crystalloid fluid should be given within the first 3 hours, as recommended by the Surviving Sepsis Campaign guidelines 1.
• Additional fluids should be guided by frequent reassessment of hemodynamic status.
• Dynamic over static variables should be used to predict fluid responsiveness, where available.
• An initial target mean arterial pressure of 65 mm Hg should be maintained in patients with septic shock requiring vasopressors.
• Resuscitation should be guided to normalize lactate in patients with elevated lactate levels as a marker of tissue hypoperfusion.

Rationale

The Surviving Sepsis Campaign guidelines provide evidence-based recommendations for the management of sepsis and septic shock, including fluid resuscitation and lactate management 1. The guidelines recommend the use of balanced crystalloids, such as lactated Ringer's, for fluid resuscitation, and emphasize the importance of frequent reassessment of hemodynamic status and dynamic monitoring to guide fluid therapy. The guidelines also recommend targeting a mean arterial pressure of 65 mm Hg and normalizing lactate levels in patients with elevated lactate. Overall, the guidelines provide a comprehensive approach to the management of sepsis and septic shock, and emphasize the importance of early recognition, rapid intervention, and ongoing monitoring and reassessment.

From the Research

Lactate during Infection

• Lactic acidosis in critically ill patients is typically due to tissue hypoxia, with sepsis being the most common cause 2.
• However, elevated lactate levels can also be caused by other factors, such as type B lactic acidosis, which is not related to tissue hypoxia or sepsis 2, 3.
• The clinical and prognostic importance of elevated lactate levels varies widely depending on the underlying cause 3.

Sodium Lactate Fluid Resuscitation

• Initial fluid resuscitation with lactated Ringer's solution may be associated with improved survival in patients with sepsis-induced hypotension compared to 0.9% saline 4.
• Lactated Ringer's solution has been shown to be more effective than normal saline in correcting acid-base balance and improving intestine injury during hemorrhagic shock 5.
• The choice of fluid for resuscitation may depend on the specific clinical context and the underlying cause of the patient's condition 4, 5.

Comparison of Lactate during Infection and Sodium Lactate Fluid Resuscitation

• Elevated lactate levels during infection are often associated with tissue hypoxia and sepsis, whereas sodium lactate fluid resuscitation is used to treat hypotension and improve acid-base balance 2, 4.
• The use of lactated Ringer's solution for fluid resuscitation may help to improve outcomes in patients with sepsis-induced hypotension, but its effects on lactate levels during infection are not fully understood 4, 5.
• Further research is needed to fully understand the relationship between lactate during infection and sodium lactate fluid resuscitation 3, 6.