Fluid and Electrolyte Balance

Question 1

intracellular fluid compartment

Answer 1

fluid IN the cells (ICF)

Question 2

extracellular fluid compartment

Answer 2

fluid OUTSIDE the cell (ECF)

interstitial space, IV fluid (plasma), cerebrospinal fluid, transcellular fluid

Question 3

isotonic solution

Answer 3

no net movement of water

Question 4

hypotonic

Answer 4

ECF sodium concentration LOWER than ICF –> water shifts into cells –> cell swelling

Question 5

hypertonic

Answer 5

ECF sodium concentration HIGHER than ICF –> water shifts out of cells –> cell shrinking

Question 6

edema: definition

Answer 6

excessive accumulation of fluid within IS spaces

–> swelling or enlargement of tissues (localized or systemic); may impair tissue perfusion; may trap drugs in ISF

factors favouring movement of fluid from capillaries or lymphatic channels –> tissues

Question 7

edema: causes

Answer 7

1. increased capillary filtration pressure
2. decreased capillary colloidal osmotic pressure
3. increased capillary permeability
4. obstruction to lymph flow

Question 8

dehydration (fluid deficit)

Answer 8

insufficient body fluid due to inadequate intake and/or excessive fluid loss

Question 9

dehydration: causes

Answer 9

vomiting and diarrhea

excessive sweating

diabetic ketoacidosis

insufficient water intake

use of concentrated formula in infants

Question 10

edema: effects

Answer 10

1. pain
2. decreased ROM
3. pitting
4. tissue breakdown
5. decreased arterial circulation `

Question 11

dehydration: manifestations

Answer 11

dry mucous membranes

d. skin turgor
d. BP, weak and rapid pulse, fatigue
i. hematocrit
d. mental function, confusion, LOC

Question 12

dehydration: compensations

Answer 12

i. thirst
i. HR
vasoconstriction of cutaneous BVs
d. urine production and i. specific gravity of urine

Question 13

function of Na+

Answer 13

regulates ECF volume and osmolarity

AP propagation

Question 14

hyponatremia: causes

Answer 14

1. excessive water gain in ECF

2. excessive loss of Na+ from body (diarrhea, vomit, sweat, diuretics, hormonal balance, renal failure)

Question 15

hyponatremia: manifestations

Answer 15

1. muscle cramps, weakness, fatigue
2. abdominal cramps, nausea, diarrhea, headache, disorientation
3. seizures, brain damage, coma, death

Question 16

hyponatremia: mechanism

Answer 16

decrease osmotic pressure –> fluid shifts into cells –> hypovolemia (decreased plasma volume) –> decreased BP

Question 17

hypernatremia: causes

Answer 17

1. water deficit in excess of Na+ deficit (GI; diarrhea, vomit or dermal; burns, excessive sweating)
2. sodium gain in excess of water gain (excessive secretion of aldosterone)

Question 18

hypernatremia: manifestations

Answer 18

thirsty

dry skin and mucous membranes

CNS changes (decreased reflexes, weakness, agitation)

Question 19

hypernatremia: mechanism

Answer 19

increased osmotic pressure –> water shifts out of cells –> cellular dehydration

Question 20

acids

Answer 20

release H+

strong acids dissociate completely

Question 21

bases

Answer 21

accept H+

Question 22

respiratory acidosis

Answer 22

hypercapnia with decreased pH (more acidic)

Question 23

RA: initiating event

Answer 23

respiratory d/o impairs alveolar ventilation –> CO2 accumulation –> H2CO3 (acid) buildup

Question 24

RA: compensation

Answer 24

kidneys conserve HCO3- and eliminate H+ in urine

Question 25

RA: manifestation

Answer 25

impaired nervous system functioning:

Headache
Lethargy
Weakness
Confusion
Coma, death

Question 26

metabolic acidosis

Answer 26

decreased serum HCO3- with decreased pH

Question 27

MA: initiating event

Answer 27

decrease in HCO3-:

1. excessive loss (diarrhea)
2. renal failure
3. increased buffering of HCO3- (non-volatile acids increasing; lactic, ketones, sulphate, phosphate)

Question 28

MA: compensation

Answer 28

lungs: increase RR to blow of CO2
kidneys: conserve HCO3- and eliminate H+ in urine

Question 29

MA: manifestations

Answer 29

impaired nervous system functioning:

Headache
Lethargy
Weakness
Confusion 
Coma, death