Why order lactic acid (lactate) versus Procalcitonin (PCT)?

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Last updated: April 8, 2025 • View editorial policy

From the Guidelines

I strongly recommend ordering lactic acid over Procal in the management of septic shock, as it serves as a more objective surrogate for tissue perfusion and is associated with worse outcomes when elevated. The Surviving Sepsis Campaign guidelines 1 emphasize the importance of lactate monitoring in septic shock, as it can help identify patients with tissue hypoxia or other causes of increased lactate levels.

Key Points to Consider

  • Lactate levels are not a direct measure of tissue perfusion, but increased levels are associated with worse outcomes 1
  • Lactate-guided resuscitation has been shown to reduce mortality in patients with septic shock 1
  • The use of lactate monitoring can help individualize the management of septic shock, particularly in patients with elevated lactate levels 1
  • Procal, on the other hand, is not mentioned in the guidelines as a recommended marker for tissue perfusion or septic shock management 1

Clinical Implications

  • Ordering lactic acid levels can help guide resuscitation efforts and improve outcomes in patients with septic shock 1
  • The results of lactate monitoring should be used in conjunction with other clinical parameters, such as blood pressure and urine output, to individualize patient management 1
  • Elevated lactate levels should prompt further evaluation and management to address the underlying cause of the elevation 1

From the Research

Lactic Acidosis Treatment

  • The treatment of lactic acidosis involves addressing the underlying cause of the condition, such as sepsis or low-flow states, rather than just treating the symptoms 2, 3.
  • Sodium bicarbonate therapy is not recommended for patients with pH at least 7.15, and its use is controversial even in more severe acidemia 3.
  • The use of other buffers, such as THAM or Carbicarb, or dialysis may be considered as alternative treatments for lactic acidosis 2.
  • Selective NHE1 inhibitors have shown promise in animal studies, improving cardiovascular function, ameliorating lactic acidosis, and reducing mortality 2.

Pathophysiology of Lactic Acidosis

  • Lactic acidosis is caused by an imbalance between the production and removal of lactic acid, which can be due to various factors such as tissue hypoxia, epinephrine-induced stimulation of aerobic glycolysis, and impaired renal function 4, 5.
  • The classification of lactic acidosis can be based on whether the pathophysiology is due to increased production or decreased removal of lactic acid 4.

Clinical Implications and Management

  • Elevated serum lactate levels are a marker of risk and a target of therapy in hospitalized patients 6.
  • The treatment of lactic acidosis should focus on addressing the underlying cause, and a strategy for its treatment should be outlined based on the mechanisms underlying lactate elevations and the risks associated with lactic acidosis 6.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Lactic Acidosis: Current Treatments and Future Directions.

American journal of kidney diseases : the official journal of the National Kidney Foundation, 2016

Research

Lactic acidosis: an update.

Clinical chemistry and laboratory medicine, 2017

Research

Lactic acidosis: Clinical implications and management strategies.

Cleveland Clinic journal of medicine, 2015

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.