Acid-base disorders

Question 1

What are the causes of normal anion gap metabolic acidosis?

Answer 1

HARDUP

H - Hyperchloraemia
A - Addisons/acetazolamide
R - Renal tubular acidosis (1, 2 and 4)
D - Diarrhoea/ DKA recovery
U - Ureteroileostomy
P - Pancreatoenterostomies

Question 2

What are the causes of high anion gap metabolic acidosis?

Answer 2

MUDPILES

M - methanol
U - Uraemia
D - DKA
P - Paracetamol
I - Isoniazid, inborn errors of metabolism
L - Lactic acidosis, Lithium
E - ethylene glycol, ethanol
S - Salicylates

Question 3

How do you calculate anion gap?

Answer 3

(Na + K) - (Cl - HCO3)

Question 4

How do you calculate albumin gap?

Answer 4

Albumin Gap = 40 - serum albumin

Corrected AG = AG + 0.25(albumin gap)

Question 5

What is strong ion difference?

Answer 5

Physicochemical approach whereby water dissociation of hydrogen ions maintains electroneutrality.

Simplified is:
SID = (Na + K) - (Cl + lactate)
SID = 40-44