Electrolytes & Fluid Balance

Question 1

What is sensible fluid loss & how much is normal?

Answer 1

• Fluid that is lost through urination and bowel movements
• 0 to 5000mL per day

Question 2

What is insensible fluid loss & how much is normal?

Answer 2

• Fluid that is lost through perspiration and vapor in exhaled air - is unmeasurable
• 600 to 900mL per day

Question 3

Colloids are … & examples

Answer 3

Large-sized substances
ex: serum proteins & blood cells

Question 4

Colloidal osmotic pressure is …

Answer 4

The power colloids have to draw water toward the area of greater concentration

Question 5

Filtration is…

Answer 5

The movement of fluid and some dissolved substances through a semipermeable membrane from a higher to a lower concentration

Question 6

Main organ responsible for filtration is the …

Answer 6

• kidneys,
• they filter 180L per day from the blood
• all but1 to 1.5L is reabsorbed

Question 7

Passive diffusion is…

Answer 7

• when dissolved substances move from an area of high to low concentration
• once equilibrium occurs, remains static

Question 8

Facilitated diffusion is…

Answer 8

• dissolved substances require a carrier molecule to help move them from one side of the membrane to the other
• does NOT need energy

Question 9

Active transport is … & an example

Answer 9

• requires energy to help move molecules from one side of the membrane to another
• does NOT depend on concentration levels
• sodium-potassium pump

Question 10

Osmoreceptors are …

Answer 10

• specialized neurons that sense the blood concentration of substances
• triggers thirst
• sensitive to changes in blood volume & BP

Question 11

Explain how the osmoreceptors control the fluid & electrolyte regulation.

Answer 11

• blood concentration becomes high
• osmoreceptors stimulate the hypothalamus to synthesize ADH (antidiuretic hormone)
• ADH is released from the posterior lobe of the pituitary gland
• inhibits urine formation by reabsorbing water from the distal & collecting tubules in the nephrons

Question 12

Describe the Control of blood pressure by the renin-angiotensin-aldosterone system

Answer 12

• Juxtaglomerular cells of the kidney sense a DECREASE in pressure, Renin is released
• renin transforms Angiotensin I to angiotensin II in the lungs
• Angiotensin II causes
  a. vasoconstriction & raises BP in arterioles
  b. releases aldosterone from the adrenal cortex causing the kidneys to reabsorb sodium
• arterial blood pressure INCREASES
• INCREASE vascular volume & arterial blood pressure

Question 13

What are natriuretic peptides & describe what they do

Answer 13

• hormone-like substance
• act against the renin-angiotensin-aldosterone system
• cause vasodilation

Question 14

Name and state where the 3 natriuretic peptides are produced

Answer 14

1. atrial natriuretic peptide
   - produced by the heart’s atrial muscle
2. brain natriuretic peptide
   - produced in the ventricles of the heart
3. C-type natriuretic peptide
   - made in the brain

Question 15

How does the ANP & BNP cause vasodilation?

Answer 15

• when the arterial & ventricular walls are overstretched they are released
• they reduce blood volume by promoting excretion of sodium & inhibiting the release of renin
• the inhibition of renin eventually limits the formation of angiotensin II
• causes diuresis by inhibiting ADH

Question 16

Hypovolemia is…

Answer 16

extracellular fluid volume deficit

Question 17

Dehydration is…

Answer 17

volume of body fluid is significantly reduced in both extracellular & intracellular compartment

Question 18

Who are at risk for hypovolemia?

Answer 18

• lethargic or depressed
• experiencing vomiting & diarrhea
• demented or difficulty with communicating needs or swallowing
• require assistance with ingestion of food/fluids
• taking drugs with anticholinergic properties

Question 19

Hemoconcentration

Answer 19

• high ratio of blood components to plasma
• increases risk for blood clots

Question 20

Factors that contribute to hypovolemia are…

Answer 20

• inadequate fluid intake
• excessive fluid loss (hemorrhage, vomiting, diarrhea, burns/wound loss)
• profuse urination/perspiration
• translocation of fluid to compartments

Question 21

Signs & symptoms of hypovolemia

Answer 21

• increased thirst
• low blood pressure
  elevated temperature
• rapid, weak, thready pulse
• rapid, shallow respirations
• scant, dark yellow urine
• warm, flushed, dry skin
• reduced cognition
• lethargic, stupor

Question 22

Labs that indicate hypovolemia

Answer 22

• elevated hematocrit & blood cell counts
• high urine specific gravity
• normal electrolyte levels

Question 23

Medical management of hypovolemia is…

Answer 23

• increase oral fluid intake
• IV fluids
• control fluid loss

Question 24

Nursing management of hypovolemia includes…

Answer 24

• increase oral fluids to 3-4L/24h
• relieve nausea, vomiting, mouth discomfort
• offer 180mL fluid with oral meds
• offer 60mL of fluid at every visit
• offer preferred fluid, popsicles, gelatin, ice cream, etc.
• offer small frequent drinks rather than large volumes
• thicken fluids accordingly

Question 25

Hypervolemia is…

Answer 25

excess volume of water in the intravascular fluid compartments

Question 26

Cause of hypervolemia is…

Answer 26

• excess intake of fluid compared to loss
• heart failure
• inadequate fluid elimination ex: kidney disease
• fluid retention secondary to excessive salt intake, adrenal gland dysfunction, or taking corticosteroid drugs

Question 27

Who are at risk for hypervolemic states?

Answer 27

• altered heart or kidney function
• increased ADH production
• receiving corticosteroid therapy, large/rapid IV fluid/colloid solutions
• excessive oral intake
• excessive salt intake

Question 28

Describe circulatory overload

Answer 28

• the fluid volume that exceeds the normal level for the intravascular space
• compromise cardiopulmonary function
• raises BP
• cause the heart to increase the force of contraction

Question 29

Signs & symptoms of hypervolemia

Answer 29

• weight gain of >2lbs/24h
• high BP
• full, bounding pulse
• moist, labored respirations
• light yellow urine
• col, pale, moist skin
• pitting & dependent edema
• swollen eyes
• crackles, gurgles in the lungs
• dyspnea or orthopnea
• easily fatigued
• distended jugular vein
• reduced cognition
• anxious

Question 30

Diagnostic findings for hypervolemia

Answer 30

• decreased hematocrit & blood cell count because of the reduced ratio of blood components to plasma
• low urine specificity

Question 31

What is the medical management of hypervolemia?

Answer 31

• restrict oral & parenteral fluid intake
• administer diuretics
• restrict salt and sodium

Question 32

Describe third-spacing

Answer 32

• translocation of fluid from intravascular or intercellular space to different tissue compartments
• fluid becomes trapped and useless
• leads to hypotension, shock, and circulatory failure

Question 33

When is third-spacing an issue?

Answer 33

• loss of colloids (hypoalbuminemia)
• burns
• severe allergic reactions

Question 34

Signs and symptoms of third-spacing

Answer 34

• same as hypovolemia
• enlargement of organ cavities (abdomen)
• generalized edema (brawny edema or anasarca)

Question 35

Hemodilution

Answer 35

• reduced ratio of blood components to plasma

Question 36

Medical management of third-spacing

Answer 36

• restore circulatory volume by eliminating trapped fluid
• administer IV solutions/colloids
• caution: can easily become hypervolumic leading to circulatory overload

Question 37

Nursing management of third-spacing

Answer 37

• assessing for hypo- and hyper-volemia
• administering IV fluid therapy & medications