Pitfalls in Lactate Interpretation

• Lactate is one of the most common biomarkers used in critical care.
• While an elevated lactate level is often attributed to impaired tissue oxygenation, an important pitfall in lactate interpretation in the critically ill is the failure to consider non-hypoxic causes of increased levels.  These include:
  • Enhanced glycolysis (B2-agonist administration, increased metabolic activity)
  • Reduced clearance (hepatic failure, renal dysfunction, muscular dysfunction)
  • Impaired tissue metabolism (mitochondrial dysfunction due to drug intoxication)
• Additional pitfalls in lactate use in the critically ill include:
  • Use of an isolated value rather than assessing longitudinal trends
  • Failure to correlate elevated lactate levels with other markers of perfusion (i.e., capillary refill time)
  • Use of rigid normalization targets rather than targeting therapeutic interventions to the full clinical picture

References

Levy B, et al. Lactate dynamics as a marker of perfusion: physiological interpretation and pitfalls. Intensive Care Med. 2025; 51:2145-8.