lactate Flashcards
What is lactate a byproduct of?
Anaerobic metabolism
What does hyperlactatemia indicate?
Elevated concentration of lactate in the blood, linked to the severity of underlying diseases
What is a lactic acidosis?
Hyperlactatemia with a concurrent metabolic acidosis
What are the two types of hyperlactatemia?
Type A and Type B
What characterizes Type A hyperlactatemia?
Decreased oxygen delivery, resulting in severe hyperlactatemia (6 to > 20 mmol/L)
What are common causes of Type A hyperlactatemia?
- Shock
- Local hypoperfusion
- Anaemia and hypoxemia
- Increased oxygen demand from muscular activity
What conditions can cause local hypoperfusion leading to hyperlactatemia?
- Gastric necrosis
- Intestinal ischemia
- Aortic thromboembolism
What triggers hyperlactatemia in severely anaemic or hypoxemic patients?
Reduced oxygen-carrying capacity in the blood
What is Type B hyperlactatemia characterized by?
Occurs without clear evidence of hypoperfusion or tissue hypoxia, resulting in a mild to moderate increase in lactate (3 to 6 mmol/L)
What are the three categories of Type B hyperlactatemia?
- Type B1: Underlying disease
- Type B2: Drug or toxin-induced
- Type B3: Inborn errors of metabolism
What conditions are associated with Type B1 hyperlactatemia?
- Sepsis
- Diabetes mellitus
- Liver disease
- Certain types of neoplasia
Which types of drugs can induce Type B2 hyperlactatemia?
- Glucocorticoids
- Beta 2-agonists
- Catecholamines
What rare metabolic disorders are associated with Type B3 hyperlactatemia?
- Pyruvate dehydrogenase deficiency
- Mitochondrial myopathies
How is lactate used as a prognostic biomarker?
High lactate levels indicate poor prognosis, but not always an absolute predictor of mortality
What lactate level in dogs with GDV indicates a higher likelihood of gastric necrosis?
Greater than 6 mmol/L
What is lactate clearance?
A gradual reduction in lactate levels, indicating the patient is responding to therapy
What conditions have prognostic value associated with lactate levels?
- Septic peritonitis
- Immune-mediated haemolytic anaemia (IMHA)
- Cardiac disease
What is the goal of using lactate as a therapeutic endpoint?
To reduce lactate levels by improving tissue perfusion and oxygen delivery
What does a 50% reduction in plasma lactate concentration within 1-2 hours indicate?
A positive sign in hypovolemic patients
What is the controversy surrounding the use of sodium bicarbonate?
Generally avoided unless severe acidosis (pH <7.1) due to potential adverse effects
- intracellular acidsosis and hypercapnia
- Acidosis of CNS (diffusion f CO2)
What can high lactate levels in abdominal effusions indicate?
Septic conditions or critical pathologies
What combination of findings in peritoneal fluid suggests septic peritonitis?
Low glucose and high lactate levels
What conditions can cause localized hyperlactatemia?
- Aortic thromboembolism
- Mesenteric vascular thrombosis
- Organ volvulus
What is the significance of persistantly high lactate after treatment in sepsis other than prognosis
May indicate microcirculatory dysfunction, so may benefit from treatments to improve microvascular haemodynamics such as vasopressors or O2
