Metabolic Alkalosis

Question 1

DDx of met alkalosis

Answer 1

BANGERED

Bartter 
Aldosteronism
NG suction
Gitelman
Excess alkalai
Renin
Emesis
Diuretics

Question 2

describe general diff b/w generation and maintenance phases of alk

Answer 2

gen: primary addition of alkali or loss of acid, renal excretion should rapidly eliminate
main: requires impairment of renal excretion of bicarb (often from hypovolemia), clnically evident w/ high serum bicarb

Question 3

causes of maintenance of alk

Answer 3

• kidney failure
• Cl losses w/ K losses (diuretics)
• ENaC activation causing K and H loss (RAAS from low volume)

Question 4

relationship b/w plasma K and bicarb reabsorption

Answer 4

lower the plasma K, more bicarb is reabsorbed

Question 5

main cause of high bicarb

Answer 5

loss of acid or Cl- from vomiting or hyperaldo

excess bicarb

Question 6

describe the generation of met alk from the loss of gastric secretions

Answer 6

loss of HCl, Na, water generates NaHCO3 in alkaline tide

this bicarb tide is mostly excreted by the kidney along with Na and K, Cl is reabsorbed in response to hypovolemia

Question 7

describe transition to maintenance phase after losing gastric secretions

Answer 7

contraction alkalosis from prolonged hypovolemia, more reabsorption of NaCl and bicarb

secondary aldo causes more K and H secretion into urine

urine will be acidic despite alkalotic state

Question 8

how does met alk develop w/ loop and thiazide diuretics

Answer 8

loss of Na and Cl, loss of ECF activates SNS and RAAS- ENaC activated and lumen more negative so loss of K and H

hypokalemia and alkalosis

Question 9

3 mech for aldo escape

Answer 9

ANP, pressure natiuresis, down regulation of NCC in DCT