Hyperlactatemia

Question 1

What is the difference between lactate and lactic acid?

Answer 1

Lactic acid is a strong acid which dissociates almost completely at physiologic pH into lactate and H+ ion.

Question 2

Define glycolysis

Answer 2

The cytosolic process (which occurs in the presence or absence of oxygen) by which 1 mole of glucose is oxidized to 1 moles pyruvate, ATP and reduced nicotinamide adenine dinucleotide (NADH)

Question 3

How does pyruvate produce ATP?

Answer 3

Pyruvate enters the mitochondria and is converted into acetyl CoA which then, in the presence of sufficient oxygen, proceeds through the tricarboxylic cycle (TCA cycle), the electron transport chain, and oxidative phosphorylation to produce 36 moles of ATP

Question 4

Type A hyperlactatemia

Answer 4

Increased oxygen demand

Exercise
Shivering/trembling
Muscle tremors
Seizures
Struggling

Decreased oxygen delivery

Systemic hypoperfusion
Local hypoperfusion
Severe anemia
Severe hypoxemia
Carbon monoxide poisoning

Question 5

Type B hyperlactatemia

Answer 5

Associated with underlying disease (B1), associated with drugs or toxins (B2), or inborn errors in metabolism (B3)

Question 6

Examples of Type B1 hyperlactatemia

Answer 6

Sepsis
Neoplasia
Diabetes mellitus
Liver disease
Thiamine deficiency
Pheochromocytoma
Hyperthyroidism
Alkalosis

Question 7

Examples of Type B2 hyperlactatemia

Answer 7

Acetaminophen
Activated charcoal
B2 agonists
Bicarbonate
Corticosteroids
Cyanide
Epinephrine
Ethanol
Ethylene glycol
Glucose
Insulin
Lactulose
Methanol
Methylxanthines
Nitroprusside
Propofol
Propylene glycol
Salicylates
Strychnine
Sorbitol
TPN
Xylitol

Question 8

Examples of Type B3 hyperlactatemia

Answer 8

Mitochondrial myopathies
Enzymatic deficiencies
MELAS (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes)