L46 + 47 + SG 1 Flashcards Preview

P&T Block 5 Renal > L46 + 47 + SG 1 > Flashcards

Flashcards in L46 + 47 + SG 1 Deck (27)
1

What cannot pass the barrier between the intravasc and interstitial spaces?

No permeable to proteins
Ex: albumin is the main protein that prevents movement of fluid into interstitium

2

What cannot pass the barrier between the interstitial and intracellular spaces?

No permeable to electrolytes b/c of the cell membrane
Goal to keep cells the same - maintain fxn

3

Explain changes to Starling forces during heart failure leading to peripheral edema.

Heart = ineffective pump
Blood packs up into venous system
Increase hydrostatic pressure intravasc -> fluid forced into interstitium = EDEMA

4

Define osmolality - inlcude units.

+ particles in 1 L water = mmol/L
Aka [ ] by number
Plasma osmolality = [electrolytes] + [nonelectrolytes]

5

What are the 2 ways that the extracellular space can epand if extra volume is present?

1. Edema - duh, into interstitium (also look at lungs)
2. HTN if expand intravasc

6

Describe scenarios in which there is volume overload (expand interstitium) but intravasc depletion

Lose oncotic pressure
Total body Na increased
- Cirrohsis w/ ascites
- Nephrotic syndrome
- CHF
- Burns (lose protein via skin)

7

What is step 1 of dx approach for hypo-osmolar states?

Posm: hypo, pseudo or hyper osmotic?

8

What is step 2 of dx approach for hypo-osmolar states?

ECF assessment - hypo, eu, or hypervolemic

9

4 causes on differential for euvolemic hypotonic hyponatremia

SIADH
Pysch pt downing H2O
Hypothyroidism
Drugs

10

Equation to calculate Posm?

Posm = 2[Na] + (BUN/2.8) + (glucose/18)

11

4 causes on differential for hypervol hypotonic hyponatremia

= pt really volume overloaded by intravasc depletion
CHF
Cirrhosis
Nephrotic syndrome
Oliguric renal failure

12

What are 5 key symptoms for dx of nephrotic syndrome?

1. Proteinuria = > 3.5gm/24 hrs
2. Hyperlipidemia - liver sees low ECV and throws fat to try to compensate
3. Lipiduria
4. Hypoalbuminemia
5. Edema (hypervol)

13

What is the U Na cut off for renal vs non-renal causes of hypovol hyponatremia?

Renal: U Na > 20 = kidney is wasting Na even though you should be saving it
Non-renal: U Na

14

3 causes on the differential for non renal hypovol hypotonic hyponatremia

1. GI losses: vomiting, diarrhea, fistula
2. Skin losses (burns)
3. Remote diuretic use

15

4 causes on differential for renal hypovol hypotonic hypoNa

1. Acute diuretics
2. Salt wasting nephropathy
3. Adrenal insuff (Addison's disease)
4. Osmotic diuretics

16

4 factors necessary in nephron to excrete free water

1. Normal GFR
2. Distal delivery of Na past prox loop of Henle
3. Intact ascending loop
4. Suppress ADH

17

What Uosm > x denotes a failure to suppress ADH?

Uosm > 100

18

What happens to the 4 steps in the kidney during hypovol?

↑Prox tubule Na reabsorption - first step to fixing the prob fast but...
↓s Distal Na delivery
↓ Loop Na reabsorption
↓ Ability to suppress ADH

19

What happens to the 4 steps in the kidney during euvolemia?

Only ↓ability to suppress ADH (think SIADH)

20

What happens to the 4 steps in the kidney during hypervolemia?

Same as hypovol b/c intravasc hypervol!

21

Symptoms of hyponatremia

Lethargy, apathy
Disorientation
Muscle cramps
Anorexia/nausea
Agitation

22

Signs of hyponatremia

Depressed deep tendon reflexes
Hypothermia
Seizures
Pseudobulbar palsy

23

Treat hypovol hypoNa

Saline

24

Treat euvol hypoNa

Water restriction
2ary: V2 receptor antag

25

Treat hypervol hypoNa

Water restriction
Maybe V2 antag and/or diuretics (for edema)

26

What are you worried about if you correct hypoNa too fast?

Osmotic demyelination
Esp if chronic hypoNa

27

What is pseudohypoNa?

More stuff in plasma so less water
Na/plasma vol = low
Pts w/ multiple myeloma, hyperlipidemia, hyperproteinemia, hyperglycemia (DKA)