From the Guidelines
Elevated lactic acid that remains high is referred to as lactic acidosis, a condition where lactic acid builds up in the bloodstream faster than it can be removed, leading to an abnormally low pH in the blood. This condition is typically categorized into two types: Type A, which results from tissue hypoxia (inadequate oxygen delivery) as seen in shock, severe anemia, or cardiac arrest; and Type B, which occurs without evidence of tissue hypoxia and may be caused by medications (like metformin), liver disease, or certain metabolic disorders 1.
Key Points
- Normal lactic acid levels are generally below 2 mmol/L, and persistent elevation above this threshold indicates lactic acidosis.
- Elevated serum lactate levels > 2 mmol/l is associated with irreversible intestinal ischemia, with a hazard ratio of 4.1 (95% CI: 1.4–11.5; p < 0.01) in established diagnosis of acute mesenteric ischemia (AMI) 1.
- Treatment focuses on addressing the underlying cause, which might include improving oxygen delivery to tissues, discontinuing offending medications, or managing the primary disease process.
- Severe lactic acidosis can be life-threatening and may require intensive care management including intravenous fluids, vasopressors, or in some cases, renal replacement therapy to clear the excess acid.
Diagnosis and Management
- Laboratory results, such as elevated l-lactate and D-dimer, may assist in the diagnosis of AMI, but are not definitive 1.
- Computed tomography angiography (CTA) should be performed as soon as possible for any patient with suspicion for AMI, despite the presence of renal failure 1.
- Comprehensive biphasic CTA includes pre-contrast scans, arterial and venous phases, and multi-planar reconstructions to assess the origin of the mesenteric arteries 1.
Recommendations
- Guiding resuscitation to normalize lactate in patients with elevated lactate levels as a marker of tissue hypoperfusion is suggested, although the evidence is weak and of low quality 1.
- Addressing the underlying cause of lactic acidosis, such as improving oxygen delivery to tissues or discontinuing offending medications, is crucial in the management of this condition.
From the FDA Drug Label
Metformin associated lactic acidosis was characterized by elevated blood lactate concentrations (>5 mmol/L), anion gap acidosis (without evidence of ketonuria or ketonemia), and an increased lactate: pyruvate ratio;
Elevated lactic acid that remains high is referred to as lactic acidosis 2.
- Lactic acidosis is a condition characterized by elevated blood lactate concentrations, anion gap acidosis, and an increased lactate: pyruvate ratio.
- It is a serious condition that can be fatal if not treated promptly.
- The risk of lactic acidosis increases with the severity of renal impairment, age, and other factors.
From the Research
Definition of Elevated Lactic Acid
Elevated lactic acid that remains high is commonly referred to as lactic acidosis. This condition is characterized by the accumulation of lactate in the blood, leading to a decrease in blood pH [(3,4,5,6,7)].
Key Features of Lactic Acidosis
Some key features of lactic acidosis include:
- High levels of lactate in the blood [(3,4,5,6,7)]
- Decreased blood pH [(3,4,5,6,7)]
- Associated with significant morbidity and mortality [(3,4,5,6,7)]
- Can be caused by various factors, including metformin use, sepsis, and acute renal failure [(3,4,6)]
Clinical Significance of Lactic Acidosis
Lactic acidosis is a serious metabolic disorder that requires prompt diagnosis and treatment. The clinical significance of lactic acidosis includes:
- High mortality risk [(3,4,5,6,7)]
- Association with severe clinical symptoms, such as fever, fatigue, vomiting, and gastrointestinal disorders 3
- Importance of early recognition and management to improve patient outcomes [(3,4,5,6,7)]