Lactate in Shock: Pathophysiology, Prognostic Value, and Resuscitation Strategy for the Cardiologist

Area of Science:

• Cardiology
• Biochemistry
• Critical Care Medicine

Background:

• Lactate is a critical biochemical marker for diagnosing and classifying circulatory failure, including septic shock.
• Established definitions and classifications (Sepsis-3, SCAI) utilize lactate levels to define shock severity and hypoperfusion.
• Lactate measurement is a key inclusion criterion in major cardiogenic shock trials and predicts mortality.

Purpose of the Study:

• To revise the understanding of lactate generation biology in shock.
• To evaluate the evolving role of lactate-guided resuscitation strategies.
• To compare lactate-targeted protocols with alternative resuscitation strategies in septic shock.

Main Methods:

• Review of current literature and pathophysiological understanding of lactate generation in shock.
• Analysis of data from landmark cardiogenic shock trials (e.g., IABP-SHOCK II, ECLS-SHOCK).
• Examination of results from septic shock resuscitation trials (e.g., ANDROMEDA-SHOCK, ANDROMEDA-SHOCK-2).

Main Results:

• Lactate generation in shock is multifactorial, involving aerobic glycolysis, microcirculatory shunting, mitochondrial dysfunction, and impaired hepatic clearance, not solely anaerobic glycolysis from hypoxia.
• Lactate kinetics correlate with patient outcomes, but trials targeting lactate normalization have yielded inconsistent results.
• Peripheral perfusion-targeted strategies may offer comparable or superior outcomes to lactate-targeted protocols in septic shock.

Conclusions:

• The pathophysiological understanding of lactate in shock has significantly evolved beyond simple tissue hypoxia.
• Lactate-guided resuscitation requires a nuanced approach, as targeting normalization alone shows mixed efficacy.
• Peripheral perfusion-focused resuscitation presents a promising alternative or adjunct to traditional lactate-based management in septic shock.