Lactic Acidosis: What is it, Causes (ex. metformin), and Subtypes A vs B

The video tutorial explains lactic acidosis, its causes, and subtypes. It begins with defining lactic acidosis and hyperlactatemia, highlighting the importance of distinguishing between them. The tutorial then delves into how lactic acid is produced and cleared in the body, focusing on glucose utilization, alanine deamination, and the Cori cycle. It outlines the pathways of lactic acid production, including glycolysis and the role of lactate dehydrogenase. The causes of lactic acidosis are categorized into increased pyruvate production, impaired mitochondrial utilization, and NADH accumulation. The video also distinguishes between Type A and Type B lactic acidosis, detailing their specific causes, such as hypovolemia, cardiac failure, diabetes, malignancy, and alcoholism.

What is the primary distinction between hyperlactatemia and lactic acidosis?

• Hyperlactatemia occurs at lactate levels greater than 4 mmol/L.

• Lactic acidosis occurs at lactate levels greater than 4 mmol/L.

• Lactic acidosis is less common than hyperlactatemia.

• Hyperlactatemia is more severe than lactic acidosis.

Which organ is primarily responsible for clearing lactic acid from the body?

• Lungs

• Kidneys

• Heart

• Liver

What is the end product of glycolysis that can be converted into lactic acid under anaerobic conditions?

• Pyruvate

• NADH

• Glucose

• Alanine

Which enzyme is responsible for converting pyruvate to lactate?

• Hexokinase

• Alanine aminotransferase

• Lactate dehydrogenase

• Pyruvate kinase

What can lead to an increased production of pyruvate, potentially causing lactic acidosis?

• Hyperkalemia

• Respiratory alkalosis

• Hypoglycemia

• Hypotension

Which condition is associated with impaired mitochondrial utilization of pyruvate?

• Hyperthyroidism

• Mitochondrial diseases

• Hypoglycemia

• Hypertension

What is a common cause of Type A lactic acidosis?

• Diabetes

• Hypovolemia

• Alcoholism

• Malignancy

Which of the following is a cause of Type B lactic acidosis?

• Sepsis

• Cardiac arrest

• Metformin use

• Hypovolemia

What effect does the Warburg effect have on cancer cells?

• Increases aerobic metabolism

• Decreases glucose uptake

• Increases anaerobic metabolism

• Decreases lactic acid production

How can alcoholism contribute to lactic acidosis?

• By causing liver dysfunction

• By increasing oxygen delivery

• By enhancing liver function

• By decreasing NADH production