Potassium, Acid-Base

Question 1

What is the definition of resolution of DKA?

Answer 1

AG normalization, normal serum ketones (specifically, beta-hydroxybutyrate)

Question 2

why is urine alkalinization used to address salicylate toxicity?

Answer 2

an alkaline pH makes an acid ionized, the ionized drug cannot be reabsorbed by the renal tubule & the ionized drug cannot get into cells. the drug gets excreted into the drug

Question 3

match the ingestion with the acid
1. methanol
2. ethylene glycol
3. toluene
a. hippuric acid
b. formic acid
c. oxalic acid

Answer 3

methanol = formic acid
ethylene glycol = oxalic acid
toluene = hippuric acid

Question 4

what acid base disorder is caused by topiramate?

Answer 4

NAGMA.
by inhibiting CAI, it can cause pRTA

Question 5

which should be replaced first when both K & Mg are low?

Answer 5

replace Magnesium first. low Magnesium can cause K wasting

Question 6

what is the treatment of ethylene glycol or antifreeze poisoning?

Answer 6

Fomepizole.
It inhibits alcohol dehydrogenase & prevents the metabolism to oxalic acid, acidosis, & crystal-induced AKI.
Continued until alcohol level is < 20mg/dl or <10 mg/dL if with end-organ damage

Question 7

what is the equation for calculated osmolality?

Answer 7

2Na + glu/18 + BUN/2.8

Question 8

what can cause a patient to have low K, nL or low BP, high urine Cl, high urine Ca?

Answer 8

Bartter’s or loop diuretics

Question 9

Is urine ketone measurement important in following DKA management?

Answer 9

No.
urinary ketones may still be high despite resolution of DKA.

Question 10

match Gitelman and Bartter syndromes with these findings:
hypercalciuria, hypocalciuria, hypomagnesemia

Answer 10

Bartter (loop like): hypercalciuria,
Gitelman (thiazide like): hypocalciuria, hypomagnesemia

Question 11

in dRTA, is the urine anion gap positive or negative? is the uOsm gap > 150 or < 150 mOsm/kg H2O?

Answer 11

dRTA: urine anion gap is (+), uOsm gap is < 150

Question 12

Renal potassium retention is suggested by what ratio of urine K:crea?

Answer 12

Urine K:crea < 15 meq/g

Question 13

A urine Cl < 10 with hypokalemia should raise concerns for

Answer 13

Surreptitious vomiting

Question 14

name 2 drugs that can cause both pRTA and dRTA

Answer 14

topiramate and zonisamide

Question 15

Name 5 drugs a/w dRTA?

Answer 15

topiramate, zonisamide, lithium, amphotericin B, toluene

Question 16

what test is useful to diagnose incomplete dRTA?

Answer 16

rapid urine acidification test with lasix 40mg and fludrocortisone 1 mg

nL: urine pH < 5.3
incomplete dRTA: urine pH > 5.3

Question 17

what is the formula for bicarbonate deficit?

Answer 17

TBW x [desired HCO3 - current HCO3]

Question 18

a uOsm gap that is < 150 is suggestive of?

Answer 18

failure of urinary acidification (eg dRTA)

Question 19

what are complications of bicarbonate therapy?

Answer 19

increased pCO2
increased lactate
decreased iCa
volume overload
hypernatremia
overshoot alkalosis
decreased tissue O2 delivery (d/t unopposed effect of RBC 2,3 DPG), - the O2 dissociation curve shifts left

Question 20

DDx for HAGMA + high osmolal gap

Answer 20

toxic alcohols; DKA, Lactic acidosis, alcohol ketoacidosis, AKI, salicylate intoxication

Question 21

what is the cause of HAGMA associated with an acquired form of glutathione deficiency?

Answer 21

pyroglutamic acidosis

Question 22

What are triggers of acquired forms of glutathione deficiency leading to HAGMA?

Answer 22

acetaminophen, vigabatrin, & dietary glycine deficiency (malnutrition, pregnancy, DM2, antibiotics)

Question 23

what is suggested by hyperchloremic metabolic acidosis, NAGMA, urine pH of > 5.5?

Answer 23

distal RTA