disorders of water balance

Question 1

hypernatremia

Answer 1

hyper-osmolality indicating a water deficit (high serum sodium concentration)

Question 2

hyponatremia

Answer 2

hypoosmolality indicating a water excess (low serum concentration)

Question 3

water in body provide information on sodium content?

Answer 3

nope

Question 4

what refers to sodium content

Answer 4

volume

Question 5

fluid in the vascular space that perfuse tissue

Answer 5

effective circulating volume

Question 6

conditions of inadequate perfusion

Answer 6

ineffective circulating volume

Question 7

conditions of ineffective circulating volume

Answer 7

1. heart failure
2. cirrhosis
3. nephrotic syndrome

Question 8

reflects total number of particles in solution

Answer 8

osmolality

Question 9

reflects total number of osmotically active particles in solution

Answer 9

osmotic pressure

Question 10

true or false:

osmotically active solute diffuse freely

Answer 10

nope

Question 11

sensor for osmolality

Answer 11

osmoreceptors in the anterior hypothalamus

Question 12

mediators for regulating osmolality

Answer 12

1. ADH/vasopressin

2. thirst

Question 13

vasopressin regulates

Answer 13

vascular smooth muscle tone

Question 14

sensor for vasopressin

Answer 14

baroreceptors in the carotid sinus

Question 15

effect of vasopressin and why

Answer 15

binds to V1aR to help limit blood loss by vasocontrisciton

Question 16

at high concentration urine is ADH high or low

Answer 16

high

Question 17

hyponatremia is definec by

Answer 17

a fall in Posm <280

Question 18

hyponatremia can occur from

Answer 18

insufficient water loss either from ADH disorder or excessive water intake

Question 19

tea and toast diet

Answer 19

low dietary solute intake with water intake

Question 20

SIADH

Answer 20

normal volume status (euvolemia) but apropiadamente ADH presence

Question 21

manifestations of chronic or actue hyponatremia:

seizure, coma, respiratory distress, cerebral herniation

Answer 21

acute

Question 22

V2 antagonist

Answer 22

blocks tubule effect of ADH

Question 23

treatment of chronic hyponatremia

Answer 23

correct underlying cause and restore balance by decreasing water and increasing solute

Question 24

in settings of normal volume status, concentrated urine is inappropriate and identifies a diluting defect

Answer 24

SIADH

Question 25

hypersomolality can be due to

Answer 25

1. diabetes insipidus 2. loop diuretics 3. sodium/solute gain

Question 26

hypernatremia usually does not occur due to

Answer 26

thrist activation

Question 27

disbetes insipidus in the absence of ADH

Answer 27

central

Question 28

diabetes insipidus in the setting of resistance of ADH

Answer 28

nephrogenic

Question 29

no or poor response to ADH

Answer 29

nephrogenic

Question 30

what doe lithium might cause

Answer 30

nephrogenic diabetes insipidus

Question 31

hyperosmolality will often be hypovolemic/euvolemic/hypervolemic

Answer 31

euvolemic

Question 32

which diuretic might block Li+ effect

Answer 32

amiloride

Question 33

managment of DI

Answer 33

1. access to water 2. ADH if central 3. limit distal solute delivery

Question 34

Plasma osmolality can often be estimated

Answer 34

by doubling the serum Na concentration incorrect when non-electrolyte osmoles are present in high concentration

Question 35

ADH is release from the posterior pituitary under circumstances of (2)

Answer 35

1) hyperosmolality sensed by the osmoreceptors of the hypothalamus, 2) significant ineffective circulating volume sensed by the carotid and aortic bodies.

Question 36

The kidney handles water by (5)

Answer 36

1) filtration, 2) bulk reabsorption in the PCT, 3) creation of a hypertonic medulla by the counter-current multiplier in the LOH, 4) creation of a dilute filtrate in the DCT, and 5) variable permeability of the CT according to the presence or absence of ADH.

Question 37

The serum Na concentration should be raised by no more than 0.5 mEq/L/hr to prevent

Answer 37

central pontine myelinolysis

Question 38

Treatment of hypoosmolality requires inducing a negative water balance with ______ water intake and ________ water excretion. Increased water excretion can be achieved by suppressing _____(if possible), blocking ______ (with drugs called Vaptans), or providing extra ______ to facilitate additional water excretion (at the same urine osmolality).

Answer 38

Treatment of hypoosmolality requires inducing a negative water balance with decreased water intake and increased water excretion. Increased water excretion can be achieved by suppressing ADH (if possible), blocking ADH receptors (with drugs called Vaptans), or providing extra osms to facilitate additional water excretion (at the same urine osmolality).

Question 39

The serum Na concentration should be lowered by no more than ____ mEq/L/hr to prevent brain swelling and herniation

Answer 39

0.5

Question 40

Treatment of hyperosmolality requires ______

Answer 40

water administration.