Acid-Base Disorders: Normal Physiology and Compensation Flashcards Preview

Nephrology Board Review > Acid-Base Disorders: Normal Physiology and Compensation > Flashcards

Flashcards in Acid-Base Disorders: Normal Physiology and Compensation Deck (35)
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1

what is the modified Henderson-Hasselbach equation?

H+ = (K+ x pCO2)/HCO3-

2

where is most of your acid eliminated?

lungs

3

how much HCO3- is reabsorbed in a day w/ a GFR of 120 ml/min?

120 ml/min x 1440 min/day x l/1000 ml x 24 mmol/l = 4080 mmol HCO3- filtered/day

4

causes of NAG metabolic acidosis

- renal causes
- extrarenal causes

5

renal causes of NAG metabolic acidosis

- distal (type 1) RTA
- proximal (type 2) RTA
- hyporenin hypoaldosteronism (type 4) RTA
- medications (acetazolamide, topiramate, ifosfamide)

6

extrarenal causes of NAG metabolic acidosis

- diarrhea
- enterovesical fistula
- "dilutional"
- hyperalimentation
- Addison's (hypoaldosteronism)

7

in proximal (type 2) RTA

dumping HCO3- in urine

8

in distal (type 1) RTA

impaired ammoniagenesis (low NH4+ excretion)

9

urine AG

urine (Na+ + K+) - (Cl-)

10

causes of proximal (type 2) RTA

- congenital (cystinosis)
- medications (acetazolamide, topiramate)
- acquired; usually Fanconi's syndrome (glycosuria, aminoaciduria, phosphaturia) from ifosfamide, tenofovir, or MM

11

symptoms of proximal (type 2) RTA

- asymptomatic
- hyperventilation as compensation from metabolic acidosis
- growth restriction in children

12

tx for proximal (type 2) RTA

- 10-15 meq/kg/day NaHCO3- and/or K+citrate
- +/- PO4 and vitamin d for normal growth in children

13

causes of distal (type 1) RTA

- hereditary causes
- acquired causes

14

hereditary causes of distal (type 1) RTA

- AD
- AR w/ deafness
- AR w/o deafness

15

acquired causes of distal (type 1) RTA

- AI causes; Sjögren syndrome, or SLE
- hypergammaglobulinemia
- chronic liver disease; primary biliary cholangitis, chronic hepatitis
- ifosfamide
- amphotericin B
- topiramate (can cause both proximal and distal RTA)

16

signs/symptoms of distal (type 1) RTA

- severe hypokalemia
- muscle weakness
- nephrolithiasis (MC calcium PHOS stones)
- nephrocalcinosis (bone is buffer)
- alkaline urine
- hypoCITRATURIA
- CKD
- osteopenia
- growth restriction in children

17

how much K+citrate do you need to neutralize daily net acid load in adult?

1-3 meq/kg/day

18

how much K+citrate do you need to neutralize daily net acid load in children?

2-5 meq/kg/day

19

serum bicarb in proximal (type 2) RTA

14-20 mmol/l

20

serum bicarb in distal (type 1) RTA

< 10 mmol/l

21

serum bicarb in hyperkalemic (type 4) RTA

16-22 mmol/l

22

UpH in proximal (type 2) RTA

5 at steady state

23

K+ in proximal (type 2) RTA

LOW

24

tx in proximal (type 2) RTA

K+citrate 10-15 mmol/kg/day

25

UpH and UAG in distal (type 1) RTA

> 5.5 and positive UAG

26

K+ in distal (type 1) RTA

LOW

27

tx in distal (type 1) RTA

K+citrate 1-3 mmol/kg/d

28

UpH in hyperkalemic (type 4) RTA

5.5-6.5

29

K+ in hyperkalemic (type 4) RTA

HIGH

30

tx in hyperkalemic (type 4) RTA

- loop diuretic
- fludrocortisone
- NaHCO3