w2_ch13_fluid &electro balance

Question 1

isotonic fluid

osmolarity & cell shift

Answer 1

270-300 mOsm/L

equal cellular shift

Question 2

hypotonic fluid

osmolarity &cell shift

Answer 2

<270 mOsm/L

cell swells

Question 3

hypertonic fluid
osmolarity & cell shift

Answer 3

> 300 mOsm/L

cell shrinks

Question 4

normal serum osmolarity (adults)

Answer 4

270-300 mOsm/L

Question 5

isotonic fluid used for? what happens when there is too much?

Answer 5

• hypotensive/hypovolemic
• risk for fluid overload (LV dys, hx CHF/htn, older adults)
• no shift until hydrostatic pressure is too high

*avoid vol hyper-expansion w/intracranial pathology or space occupying lesions

Question 6

hypotonic fluids

Answer 6

• dilutes serum decreasing osmolarity
• cellular dehydration & normal b/p
• used for medication
• cautions: cardiovascular collapse, increase ICP

Question 7

hypertonic fluids

Answer 7

• higher osmolarity than serum
• increases serum osmolarity
• cell shrinks
• stabilize b/p, increase urine output, decrease edema
• most D5 solutions

Question 8

what is corrected by using hypertonic fluids?

Answer 8

fluid, electrolyte, and acid-base imbalance

Question 9

what type of fluids for a patient with decrease skin turgor, dry mucous membranes, and normal b/p

Answer 9

hypotonic fluid

Question 10

colloids

Answer 10

• blood
• blood products, plasma
• plasma fraction
• synthetic plasma expanders (albumin and synthetic albumin)

Question 11

what type of fluids for a patient with decrease skin turgor, dry mucous membranes, and hypotension

Answer 11

isotonic

• will fill vascular and increase b/p then when vessels are filled then hydrostatic pressure fills the cells

Question 12

crystalloids, advantages & disadvantages

Answer 12

• water + electrolyte, small molecules
• advant: inexpensive, long shelf life, low adverse reactions, variety of formulations for fluid replacement/balance
• dis: 2-3x volume to correct vascular expansion but wont stay d/t hydrostatic pressure

Question 13

colloids

Answer 13

• large molecules that stay in vascular
• high osmolarity (brings fluid to vascular)
• stays in the vascular longer than crystalloids

Question 14

patient that will benefit from colloids

Answer 14

• reduces edema
• helps maintain b/p
• protein malnourished pt
• liver failure pt

Question 15

5% dextrose (D5W), uses?

Answer 15

• sugar & water
• in the bag = isotonic, bloodstream = hypotonic
  (glucose metabolizes)

Uses: maintain water balance when NPO
- provides calories
- electrolyte free
- rapid resdistribute into ICS, less than 10% stays in IVS

Question 16

dextrose-saline

Answer 16

• a bit of sugar and salt
• primarily to replace water loss post-op
• neither really saline or dextrose
• advantages: doesn’t commonly cause water/salt overload

Question 17

how to assess volume status (determine IVF)

Answer 17

• what is the volume status of my pt?
• do we want to shift fluid to another compartment?
• can my patient take PO safely?
• is my pt NPO for a reason?
• is the patient diabetic?
• what fluids was the pt on before?

Question 18

how does hydrostatic pressure effect fluid shift?

Answer 18

it pushes the fluid out of the vessels d/t increased pressure in the vessels

Question 19

how does oncotic pressure effect fluid shift?

Answer 19

the protein in the vessels stay in the vessels and when the hydrostatic pressure in the vessel decreases the protein pulls water back into the vessels

Question 20

osmolality vs omolarity

Answer 20

osmolality - measures solvent (fluid) concentration for kidneys

osmolarity - measures concentration (particles) in the blood

Question 21

regulation mechanisms

Answer 21

• thirst
• kidneys (vol & osmolality)
• RAA mech, responds to HTN, vasoconstriction, Na+ regulation
• ADH,

Question 22

sodium function

Answer 22

• maintains ECF volume
• regulates acid base balance w/other ions
• conducts nerve impulses

Question 23

potassium function

Answer 23

• major cation of ICF
• cellular depolarization & repolarization
• neuromuscular impulses
• acidbase balance
• cardiac contractions

Question 24

calcium function, regulation of it

Answer 24

• neuromuscular transmission
• muscle contraction
• bones & teeth
• requires vitamin d

regulated by
- vit D
- calcitonin
- parathyroid hormone (PTH)

Question 25

magnesium function

Answer 25

• skeletal muscle contraction
• neurotransmission
• generation of energy stores
• carbohydrate metabolism
• blood coagulation
• cell growth