From the Guidelines
Normal lactate levels in the blood typically range from 0.5 to 2.2 millimoles per liter (mmol/L) at rest. Values above 2.2 mmol/L are considered elevated, with levels above 4 mmol/L indicating significant hyperlactatemia that requires prompt medical attention 1. Lactate is produced during anaerobic metabolism when oxygen supply is insufficient to meet tissue demands. The body normally clears lactate efficiently through the liver and kidneys, maintaining these normal levels. Elevated lactate can indicate tissue hypoxia, sepsis, shock, liver dysfunction, or other serious conditions. Lactate levels are commonly measured in emergency and critical care settings to assess tissue perfusion and oxygenation. Patients with elevated lactate may require fluid resuscitation, oxygen therapy, treatment of underlying infections, or other interventions depending on the cause. Serial lactate measurements are often used to monitor treatment response, with decreasing levels suggesting clinical improvement.
Key Points
- Normal lactate levels: 0.5-2.2 mmol/L at rest
- Elevated lactate levels: above 2.2 mmol/L
- Significant hyperlactatemia: above 4 mmol/L
- Lactate clearance is an important marker of tissue perfusion and oxygenation
- Guiding resuscitation to normalize lactate levels is a recommended approach in patients with septic shock 1
Clinical Implications
Lactate levels are a crucial marker of tissue hypoperfusion and oxygenation. Elevated lactate levels can indicate serious underlying conditions, and prompt medical attention is necessary to prevent morbidity and mortality. Serial lactate measurements can be used to monitor treatment response and guide resuscitation efforts. Guiding resuscitation to normalize lactate levels is a recommended approach in patients with septic shock, as it can improve outcomes and reduce mortality 1.
From the Research
Normal Lactate Levels
- Normal lactate range is less than 2.3 mmol/L, as stated in the study 2
- Lactate levels within the "normal" range can be a useful prognostic indicator in septic shock 2
- A lactate concentration of 1.4 mmol/L or less is considered a beneficial response to vasopressin infusion in septic shock patients 2
Lactate Levels and Mortality
- Lactate levels are closely related to morbidity and mortality in patients with septic shock 3
- Elevated lactate levels are associated with increased mortality in patients with severe sepsis or septic shock 4
- A combination of lactate clearance rate and central venous oxygen saturation may serve as an index for confirming the endpoint of fluid resuscitation in patients with septic shock 5
Lactate Clearance Rate and Central Venous Oxygen Saturation
- Lactate clearance rate and central venous oxygen saturation are useful endpoints for guiding fluid resuscitation in patients with septic shock 6, 5
- A lactate clearance rate of 10% or more (or lactate ≤ 2.0 mmol) and a central venous oxygen saturation of 70% or more are considered target values for fluid resuscitation therapy 5
- The combination of lactate clearance rate and central venous oxygen saturation may be more accurate and reliable than central venous oxygen saturation alone for guiding fluid resuscitation in patients with septic shock 5