L50 + 51 Flashcards Preview

P&T Block 5 Renal > L50 + 51 > Flashcards

Flashcards in L50 + 51 Deck (32)
1

What is compensation?

Development of a 2ary AB disorder to help correct the 1ary

2

Does compensation return the pH to normal?

NO
If back to normal, you should suspect mixed

3

How do you get rid of H+ in the urine?

Prox tubule
Carbonic anhydrase for bicarb reabsorption
To gain bicarb, you lose H

4

What does low PaCO2 mean practically?

Hypervent (1ary or 2ary)
CO2 = acid

5

Name the 4 steps of compensating for high H+ in the blood and the timeframe in which each occurs.

1. Buffer with bicarb in blood - immediate
2. Resp comp - mins
3. Intracell buffering - hrs
4. Renal H+ secretion - days

6

How is H+ secreted in urine?

Ammonium

7

If you have a metabolic acidosis and your urine is acidic, does that imply a renal or non-renal source of increased H+ produciton?

Non-renal
You're excreting protons as you should to increase your bicarb

8

If you have a metabolic acidosis and your urine is basic, does that imply a renal or non-renal source of increased H+?

Renal
1. Renal tubular acidosis = H+ secretion impaired so losing bicarb
2. Chronic kidney disease = ↓nephron #

9

What are the effects of metabolic acidosis on the body?

Hb/O2 curve shifts R = dissociation, more O2 delivered to tissues
↓CNS
Arrhythmia
↓Cardiac contractility
Hyper K
↓Pulm BF

10

What GI problem would cause a metabolic acidosis?

Diarrhea - losing bicarb

11

Formula for anion gap

Na - (HCO3 + Cl)
Acid minus the bases

12

Mudplies for anion gap metabolic acidosis

Methanol (formaldehyde)
Uremia (creatinine)
DKA (ketones)
Propylene glycol
Lactate
Iron tabs/isoniazid
Ethylene glycol (anti-freeze look for oxalate)
Salicylates

13

Heart CCU for non-gap metabolic acidosis

Hyperalimentation (feeding tube)
Expansion
Acetazolamide
Renal tubular acidosis
Diarrhea
Cholestyramine
Carbonic anhydrase inhibitors
Utererosigmoidostomy

14

If you're normally reabsorbing bicarb in the kidney by excreting H into urine, where are you naturally compensating by doing the opposite?

Colon - bicarb into poop, reabsorb H
Why diarrhea loses bicarb -> acidosis

15

Describe the metabolic acidosis caused by renal tubular acidosis
- Gap?
- Urine pH

↑Cl metabolic acidosis
Non-gap
Urine pH not max acid (aka should be more acidic to compensate for acidosis)

16

Effects of metabolic alkalosis on the body

Left shift Hb/O2 curve: ↓O2 tissues
↓Cerebral blood flow
Arrhythmia
Tetany
Seizure

17

Extra-renal causes of metabolic alkalosis

HypoK
GI:
1. Bicarb ingestion (antacids)
2. Vomiting
3. NG suctioning

18

Renal cause of metabolic alkalosis

Diuretics!

19

What is the main difference between transient and maintained metabolic alkalosis?

1. Maintained: H+ secretion increased
Some stimulus to make prox tubule reclaim all the bicarb
2. Volume, Cl- or K+ depletion occurs during HCO3 loading

20

Why does volume depletion lend to akalosis?

Vol depleted - want to reabsorb Na
via Na/H exchanger
Must secrete H

21

Why does ↓Cl- lend to alkalosis?

Cl depleted - there is no Cl- in the urine to reabsorb
Conversion to mostly alpha intercalated cells = H secreting cells

22

Why does ↓K lend to alkalosis?

@ renal tubular cell
To reabsorb K, you have to secrete H to maintain electrical neutrality

23

When does Cl- loss and HCO3 load occur at the same time?

Vomiting
Lose Cl- from stomach acid
Therefore bicarb from the stomach rises
Look at image in slides

24

3 causes of transient metabolic alkalosis

1. Bicarb loading
Exogenous = tumor lysis syndrome
Endo = bone dissolution from immobility
2. Recovery from met acidosis
3. Post-hypercap resp acidosis

25

↓Cl- or vol depleted causes of persistent metabolic alkalosis

Vomiting
NG suction
Diuretics
Post-hypercap alkalosis

26

↓K causes of persistent metabolic acidosis

"Saline resistant"
HypoK
Aldosterone excess
Diuretics
Renal failure due to ↓GFR

27

↓Cl- AND K causing metabolic alkalosis

Liddle's syndrome
Bartter's & Gitelman's

28

What does urine Cl tell you about a persistent metabolic alkalosis?

U Cl
UCl 20 (norm) - check U K

29

What does urine K tell you about persistent metabolic alkalosis?

U K 20 = (high) renal/hyperaldo cause K

30

Is maintained metabolic acidosis associated with basic or acidic urine?

Maintained metabolic alkalosis associated with paradoxical aciduria

31

4 causes resp acidosis

CNS depressants
Resp muscle dysfxn
Airway obstruction
Poor gas exchange

32

5 causes resp alkalosis

1. Hypoxia
2. Lung disease
3. Sepsis
4. Salicylates
5. CNS stim