11.3: {Na] Flashcards Preview

MHD V: Renal > 11.3: {Na] > Flashcards

Flashcards in 11.3: {Na] Deck (42):
1

What is blood [Na] equal to?

Total body Na / Total body water

2

What does water excess w/o change in body Na Cause?

Hyponatremia

3

How does body respond to increased water intake?

- [Na] drops
- Decrease thirst and ADH release
- Increased renal excretion and decreased thirst normalize

4

Other names of ADH?

- AVP
- Vasopressin

5

ADH action?

- Produced by hypothalamus stored in post. pit.
- Acts on distal tubule increase H20 resorption
- Leads to increase urine []
- Causes constriction as well

6

Definition of concentrated urine?

- Urine osmolality > plasma
- Plasma osmolality usually 300

7

How is ADH regulated?

- Increased osmolality increased ADH release
- Larger decrease in V. or P. leads to release
- P and V can overcome osmolality

8

ADH more sensitive to osmolality or P and V?

- Osmolality

9

% of body weight that is salt water?

60%

10

What is SIADH?

- Syndrome of Inappropriate ADH
- Increase body water with normal [Na]
- Tumor producing ADH

11

What is a water pill?

- Diuretic
- Tells body to get rid of salt and water

12

What can cause hyponatremia?

1. SIADH
2. Diuretic use with water intake
3. Increased TBW and smaller increases in Na

13

Why is hyponatremia solely from fluid ingestion rare?

Body can create extremely dilute urine by using close to no ADH

14

What is hyponatremia usually due to?

- Impaired renal water excretion
1. Impaired dilution due to excess ADH
2. Intrarenal factors
- Might be ingesting high volume and low solute: beer drinks syndrome, but this is rare

15

Can body produce pure water?

- No, some Na must be secreted with water
- 50 is lowest body can go
- If you have high water intake and low osmolar intake
- You will pee out all your osmoles

16

Intrarenal factors leading to hyponatremia?

1. Renal failure (decreased GFR)
2. Diuretics preventing resorption in distal tubule to create free water
3. Solute avidity in prox tubule (CHF) must be able to deliver solute to distal

17

3 types of hyponatremia? And want it says about TBNa?

1. Hypovolemic: decreased TBNa
2. Euvolemic: Normal TBNa
3. Hypervolemic: Increased TBNa

18

Signs of hypovolemia?

1. Flat neck veins
2. Orthostatic Hypotension
3. Decreased skin turgor

19

Causes of Euvolemic hyponatremia?

1. SIADH
2. Hypothyroidism
3. Beer drinkers
4. Psychogenic polydypsia
- Normal body Na but too much water

20

When is edema seen?

Hypervolemic hyponatremia

21

What causes hypervolemic?

1. CHF
2. Liver Cirrhosis
3. Renal failure

22

What causes hypovolemic?

1. Renal Na loss
2. Diuretics
3. Diarrhea / vomiting
4. Addison's disease

23

What does low Urine Na indicate?

- Extrarenal loss of Na
- Or edematous disorder

24

What does salt avid kidneys mean?

- Like to resorb salt
- Seen in CHF

25

What does normal urine Na suggest?

- Renal loss of Na
- Or excess ADH

26

What is hypernatremia?

Increased [Na] with a decrease in TBW relative to Na

27

Pathogenesis of Hypernatremia?

- In impaired water intake, kidneys can only concentrate urine to a fixed extent of 1200 to minimize water loss
- However there is still insensible water loss that will lead to HYPERnatremia
- This is why we can live without water, if you aren't peeing it off, you are evaporating it off

28

3 types of hypernatremia?

1. HYPOvolemic: decrease TBNa
2. EUVOlemic: decrease TBW, static TBNa
3. HYPERvolemic: Increase TBNa

29

Causes of hypo hypernatremia?

1. Renal / extrarenal loss w/ inadequate H2O intake
2. Osmotic Diuresis

30

Causes of Euvo hyperNa?

1. Central diabetes insipidus: trauma / tumor
2. Nephrogenic diabetes insipidus: drugs, genetic, HyperCa
3. Decreased thirst / water intake

31

Causes of HYPER hyperNa?

1. Hypertonic fluids
2. Mineralocorticoid excess
3. Salt poisoning / sea water

32

Treatment of Causes of hypo hypernatremia?

1. Hypotonic fluids to repair volume depletion

33

Treatment Causes of Euvo hyperNa?

1. Water administration
2. ADH in central diabetes insipidus

34

Treatment of HYPER hyperNa?

1. Water + ADH to remove excess Na
***Care to not exceed .5m eq /L/Hr to not shift water into brain leading to brain edema

35

How to treat acute hyponatremia?

- This is what will be seen in marathon runners
- Inject hypertonic saline

36

What excludes beer drinkers syndrome or Polydipsia?

Urine osmolality > plasma

37

How do you treat SIADH?

VAPTANs

38

Difference between dehydration and volume depletion?

Dehydration: water deficit
Volume depletion: Salt and water deficit

39

How do you treat hypovolemic hyponatremia?

- Saline

40

How do you treat hypervolemic hyponatremia?

Diuretics and fluid restriction

41

How do you treat euvolemic?

Mild asymptomatic: no treatment needed
Severe (

42

Symptoms of symptomatic euvolemic?

1. Confusion
2. Seizures
3. Coma