Metabolic Acidosis Quick Refresher

Question 1

Metabolic acidosis is defined as

Answer 1

arterial pH < 7.35 and serum bicarbonate < 22 mEq/L

Question 2

Three general mechanisms causing MA

Answer 2

a. increased acid production
b. decreased acid excretion
c. increased bicarb excretion

Question 3

Workup for MA

Answer 3

CMP and calculate anion GAP

Question 4

Calculate anion gap

Answer 4

Na - (Cl + HCO3) =
(3-10) - normal
> 10 = elevated

Question 5

Most common cause of MA in sepsis

Answer 5

increased lactic acid due to decreased organ perfusion

Question 6

Mnemonic for MA with elevated anion gab

Answer 6

Methanol
Uremia
DKA
Paraldehyde, paracetamol (acetaminophen),
Isoniazid, iron pills
Lactic acid (Sepsis)
Ethylene glycol, ethanol 
Salicylic acid