From the Guidelines
Elevated lactate is a common finding in patients with significant gastrointestinal bleeding, as it reflects the severity of hypovolemia and tissue hypoperfusion. The relationship between lactate levels and the severity of bleeding is well-established, with higher lactate levels associated with more substantial blood loss and worse outcomes 1. This is because GI bleeding leads to hypovolemia, reduced tissue perfusion, and a shift to anaerobic metabolism, resulting in the production of lactic acid. Additionally, the liver's ability to clear lactate from the bloodstream may be impaired during a bleeding episode, further contributing to lactate accumulation. Key points to consider in the management of GI bleeding include:
- Lactate levels serve as a useful prognostic marker, with elevated levels (>2 mmol/L) associated with increased mortality, need for intervention, and transfusion requirements.
- Serial lactate measurements can help monitor response to resuscitation efforts, with decreasing levels generally indicating improvement.
- When managing GI bleeding, lactate levels should be checked at presentation and monitored during treatment alongside other vital signs, hemoglobin levels, and clinical assessment to guide resuscitation efforts and determine the need for urgent intervention 1. It is essential to prioritize the management of hypovolemia and tissue hypoperfusion in patients with GI bleeding, as these factors contribute to elevated lactate levels and worse outcomes 1.
From the Research
Elevated Lactate in GI Bleed
Elevated lactate levels can be observed in various clinical conditions, including gastrointestinal (GI) bleeding. The following points summarize the relationship between elevated lactate and GI bleed:
- Elevated lactate levels are not exclusive to tissue hypoxia/hypoperfusion and can result from increased or accelerated aerobic glycolysis during the stress response 2.
- Lactate levels can be elevated for many reasons, and tissue hypoperfusion may be the most common cause of elevation, but many other etiologies or contributing factors exist 3.
- A study found that elevated lactate level predicts intensive care unit admissions, endoscopies, and transfusions in patients with acute gastrointestinal bleeding 4.
- Patients with an elevated lactate level were more likely to be admitted to ICU, receive PRBC transfusion, and undergo endoscopy than patients with a normal lactate level 4.
- Lactate measurement may be a useful adjunctive test in the triage of patients with acute GI bleed, as it can identify patients who require more intensive care and intervention 4.
Clinical Significance of Elevated Lactate
The clinical significance of elevated lactate levels in GI bleed is multifaceted:
- Elevated lactate levels can indicate poor prognosis and increased risk of complications, such as the need for ICU admission, transfusions, and endoscopies 4, 5.
- Lactate levels can be influenced by various factors, including epinephrine-stimulated Na+,K+-ATPase activity, which can lead to increased aerobic glycolysis and lactate production 6.
- The relationship between lactate levels and tissue hypoxia/hypoperfusion is complex, and lactate levels should be interpreted in the context of other clinical variables and indicators of perfusion 2, 6.