Water, Sodium, and Potassium Balance Disorders

Question 1

Conditions of Inappropriate Water Balance

Answer 1

Edema
Third-spacing
Dehydration
Volume depletion
ADH abnormalities

Question 2

Edema

Answer 2

an increase in the interstitial fluid compartment due to extracellular fluid volume excess

Question 3

What does edema result in?

Answer 3

swelling
Brain, laryngeal, or pulmonary edema can be life threatening
Peripheral edema may increase susceptibility to injury, ischemia, or interfere with function

Question 4

Edema is evident when the interstitial volume has increased by at least _________L.

Answer 4

2.5 L (25%)

Question 5

How can edema be assessed?

Answer 5

by daily weights (1 L of water weighs 2.2 lbs) visual inspection, measurement of affected area, palpation, or imaging studies

Question 6

What can edema result in response to?

Answer 6

1. increased capillary pressure due to increased volume, venous obstruction, decreased arteriolar resistance
2. Decreased colloidal osmotic pressure
3. Increased capillary permeability
4. Obstruction of lymphatic flow

Question 7

Third spacing a the trapping of ECF in the transcellular space. This space includes:

Answer 7

includes peritoneum, pleura, pericardial sac

Question 8

rest of slide 5

Question 9

Dehydration

Answer 9

largely refers to intracellular water deficits stemming from hypertonicity and a disturbance in water metabolism
-it is basically a loss of TBW
-using or losing more water than take in

Question 10

Volume depletion

Answer 10

describes the net loss of total body sodium and a reduction in intravascular volume
-Best termed extracellular fluid volume depletion

Question 11

Hypovolemia

Answer 11

effective circulating blood volume is compromised

Question 12

What are S/S of hypovolemia

Answer 12

weakness, fatigue, headache, dry skin and mucus membranes, thirst, dark urine (high specific gravity, high urine osmolality), hypotension, tachycardia

Question 13

What is SIADH ? and what is it characterized by?

Answer 13

Syndrome of Inappropriate ADH secretion. It is characterized by excessive release of ADH from the posterior pituitary due to failure of negative feedback system or secretion from non-pituitary structures

Question 14

Slide 7

Question 15

What are the cardinal features of SIADH?

Answer 15

Hypotonic hyponatremia
Natriuresis
Urine osmolality greater than serum osmolality
Absence of edema and volume depletion
Normal renal and adrenal function

Question 16

What does Diabetes insipidus result from?

Answer 16

deficiency of or decreased response to ADH

Question 17

What does Diabetes insipidus result in?

Answer 17

excessively dilute urine (3-20 L/day) and polydipsia

Question 18

slide 9

Question 19

Sodium losses (hyponatremia) are conditions of the _______, _____ or _____ can alter bodies’ ability to hold on to sodium

Answer 19

renal system, GI tract, skin

Question 20

Sodium losses causes

Answer 20

Kidney changes: diuresis
GI tract: diarrhea, vomiting, NG tube suction, enemas
Skin changes: excessive sweating, burns
Miscellaneous: SIADH, psychogenic polydipsia

Question 21

Hyponatremia plasma concentration is

Answer 21

< 135,
normal is 135-145

Question 22

In hyponatremia, plasma values reflect ____________ NOT absolute amount

Answer 22

sodium CONCENTRATION

Question 23

Sodium accounts for 90% of _____________ of ________ so serum osmolality usually changes with changes in sodium concentration

Answer 23

osmolality, ECF

Question 24

finish the rest of pptw