11.3: {Na]

Question 1

What is blood [Na] equal to?

Answer 1

Total body Na / Total body water

Question 2

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

Answer 2

Hyponatremia

Question 3

How does body respond to increased water intake?

Answer 3

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

Question 4

Other names of ADH?

Answer 4

• AVP

- Vasopressin

Question 5

ADH action?

Answer 5

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

Question 6

Definition of concentrated urine?

Answer 6

• Urine osmolality > plasma

- Plasma osmolality usually 300

Question 7

How is ADH regulated?

Answer 7

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

Question 8

ADH more sensitive to osmolality or P and V?

Answer 8

• Osmolality

Question 9

% of body weight that is salt water?

Answer 9

60%

Question 10

What is SIADH?

Answer 10

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

Question 11

What is a water pill?

Answer 11

• Diuretic

- Tells body to get rid of salt and water

Question 12

What can cause hyponatremia?

Answer 12

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

Question 13

Why is hyponatremia solely from fluid ingestion rare?

Answer 13

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

Question 14

What is hyponatremia usually due to?

Answer 14

• 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

Question 15

Can body produce pure water?

Answer 15

• 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

Question 16

Intrarenal factors leading to hyponatremia?

Answer 16

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

Question 17

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

Answer 17

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

Question 18

Signs of hypovolemia?

Answer 18

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

Question 19

Causes of Euvolemic hyponatremia?

Answer 19

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

Question 20

When is edema seen?

Answer 20

Hypervolemic hyponatremia

Question 21

What causes hypervolemic?

Answer 21

1. CHF
2. Liver Cirrhosis
3. Renal failure

Question 22

What causes hypovolemic?

Answer 22

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

Question 23

What does low Urine Na indicate?

Answer 23

• Extrarenal loss of Na

- Or edematous disorder

Question 24

What does salt avid kidneys mean?

Answer 24

• Like to resorb salt

- Seen in CHF

Question 25

What does normal urine Na suggest?

Answer 25

- Renal loss of Na | - Or excess ADH

Question 26

What is hypernatremia?

Answer 26

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

Question 27

Pathogenesis of Hypernatremia?

Answer 27

- 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

Question 28

3 types of hypernatremia?

Answer 28

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

Question 29

Causes of hypo hypernatremia?

Answer 29

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

Question 30

Causes of Euvo hyperNa?

Answer 30

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

Question 31

Causes of HYPER hyperNa?

Answer 31

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

Question 32

Treatment of Causes of hypo hypernatremia?

Answer 32

1. Hypotonic fluids to repair volume depletion

Question 33

Treatment Causes of Euvo hyperNa?

Answer 33

1. Water administration | 2. ADH in central diabetes insipidus

Question 34

Treatment of HYPER hyperNa?

Answer 34

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

Question 35

How to treat acute hyponatremia?

Answer 35

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

Question 36

What excludes beer drinkers syndrome or Polydipsia?

Answer 36

Urine osmolality > plasma

Question 37

How do you treat SIADH?

Answer 37

VAPTANs

Question 38

Difference between dehydration and volume depletion?

Answer 38

Dehydration: water deficit | Volume depletion: Salt and water deficit

Question 39

How do you treat hypovolemic hyponatremia?

Answer 39

- Saline

Question 40

How do you treat hypervolemic hyponatremia?

Answer 40

Diuretics and fluid restriction

Question 41

How do you treat euvolemic?

Answer 41

Mild asymptomatic: no treatment needed | Severe (

Question 42

Symptoms of symptomatic euvolemic?

Answer 42

1. Confusion 2. Seizures 3. Coma