Nephro - Na - Online MedEd

Question 1

Disorders of Na are actually disorders of __

Answer 1

H2O

Na is marker of tonicity of blood and has nothing to do with salt

Question 2

Blood and cells separated by

Answer 2

Semi-permeable membrane

Question 3

Hyponatremia - too little Na in blood so…

Answer 3

So H2O will flow from blood to cells
Causes swelling of cells
This is balance out tonicity
Swelling = bad

Question 4

Hypernatremia - too much Na in blood so…

Answer 4

So H2O will flow from cells to blood
Causes shrinkage of cells
Shrinkage = bad

Question 5

The degree of symptoms with swelling and shrinkage of cells will depend on….

Answer 5

Rate of Na change
Na change/Time
Acute changes - more symptoms

Question 6

Symptoms of hypoNa and hyperNa

Answer 6

Mild - asymptomatic
Mod - N/V, confusion, headache
Severe - coma, seizures

Question 7

How to fix hyperNa

Answer 7

For degrees of Na change
HyperNa = free water deficit = dehydration
Mild - best way is to replace by mouth - oral H2O
Severe - D5W (give hypotonic)
Mod - IVF NS

Question 8

How to fix hypoNa

Answer 8

Dependent on diagnosis
Severe - hypertonic Na, 3% NaCl (out of danger zone)
Mod - IVF NS
Mild/asymptomatic - need to figure out diagnosis, will be disease specific

Question 9

Pathophys of hypernatremia to hyponatremia

Answer 9

HyperNa - dehydration/free water deficit

HypoNa - ddx

Question 10

Hyponatremia - what is the first test to do

Answer 10

Serum osmoles
2xNa + glucose/1.8 + BUN/2.8 = normal is 280
1) Serum osmoles are normal = this is isotonic hyponatremia = pseudohyponatremia
-Caused by lab abnormality (fats and proteins)
-So if serum osmoles are normal, there is no disorder
2) Serum osmoles are elevated - hypertonic hyponatremia
-Something in the equation or something else that is causing hypertonic (glucose, EtOH). So the Na decreases to keep the equation normal
-Happens in diabetic
-For every 100 BG above first 100, need to correct Na by 1.6 (ex. 500 BG, correct Na 4x1.6 = 6.5). If Na is 130 –> now 136.5 by correction
-i.e. give insulin
3) Hypotonic hyponatremia - true hypotonic hyponatremia
-Need Hx and Px to decide volume status
-Volume up - correct Na by diuresis
-Volume down - correct by IVF
-Euvolemic - RATS
-Renal tubular acidosis (urinalysis, lytes), Addison’s (cortisol), Thyroid (TSH), SIADH (dx of exclusion)

Question 11

SIADH

Answer 11

Volume restriction
Gentle diuresis
Demeclocycline

Question 12

Urine sodium should be tested in hypotonic hyponatremia… this is to look at

Answer 12

Aldosterone

Question 13

Urine ormole should be tested in hypotonic hyponatremia… this is to look at

Answer 13

ADH

Question 14

Osmotic demyelination

Answer 14

If correct Na too quickly… may get spastic, quadriplegia
0.25 per hour
need correction of 4-6 on first day to alleviated symptoms
exception: to stop seizure