Acid Base 1

Question 1

avg normal urine pH

Answer 1

6

below 5.3 is acidic

Question 2

describe citrate role in homeostasis

Answer 2

converted to organic acids and bicarb by liver, excreted by kidney

w/ acidemia= low urinary citrate
alkalemia= high urinary citrate

Question 3

PCT role in pH regulation

Answer 3

bicarb reabsorption- H+ is secreted and binds to lumen bicarb, carbonic acid converted to CO2 and water by CA

CO2 moves into cell, converted back to bicarb by CA and to circulation via Na/bicarb cotransport

Question 4

alpha intercalated cell role in pH regulation

Answer 4

secrete H+ via ATPase, this is buffered by dibasic phosphate (titratable) and ammonia (fixed)

ammonia is what can be upregulated to increase acid removal

Question 5

3 types of causes of met acidosis

Answer 5

all cause fall in bicarb

1. loss of bicarb from GI or kidney (proximal RTA)
2. less renal excretion- either distal RTA or kidney injury
3. excess acid- either endogenous (DKA) or exogenous (methanol, glycols, ASA)

Question 6

2 types of met alkalosis causes

Answer 6

cause rise in bicarb

1. loss of acid- from GI (vomiting) or kidney (hyperaldosteronism)
2. excess bicarb from administration

Question 7

how to determine acid base compensation?

Answer 7

127-1424

met acidosis- PCO2 down 1.2x(change in bicarb)
met alkalosis- PCO2 up 0.7 x(change in bicarb)

res acidosis- for every 10 up in CO2, bicarb up 1-4 (acute to chronic)
res alkalosis- for every 10 down in CO2, bicab down 2-4

Question 8

DDx for AG met acidosis

Answer 8

GOLDMARK

Glycols
Oxoproline
L-lactate
D-lactate
Methanol
Aspirin
Renal Failure
Ketoacidosis

Question 9

elevated osmolar gap

Answer 9

w/ high AG calculate osm gap: Calculated Osm-measured osm

indicates methanol or glycol AG met acidosis

can also be mannitol or isopropyl alcohol

Question 10

main causes of normal AG met acidosis

Answer 10

diarrhea and RTA