WHAT IS IT? Lactate (conjugate base of Lactic acid) is formed from anaerobic metabolism of pyruvate by lactate dehydrogenase in the setting of insufficient oxygen. Lactate acts as a serum marker for end organ perfusion. Increased Lactate= Increased ischemic damage to tissue (severity of shock). It is cleared by the liver and kidneys.
As cells are starved of oxygen and substrate, they can no longer sustain aerobic oxygen production.
Eventually, cellular metabolism is no longer able to generate enough energy to power the components of cellular homeostasis, leading to disruption of cell-membrane Na/K+ ionic pumps.
Sodium moves into the cell making it hypertonic relative to the ECF. The cell swells, the cell membrane breaks down and cell death occurs.
Schwartz’s Principles of Surgery, 10e. Chapter 5: Shock. Brian S. Zuckerbraun; Andrew B. Peitzman; Timothy R. Billiar