Fluid & Electrolytes

Front 1

the most frequently encountered fluid and electrolyte problems are the result of...

Back 1

clinical situations which carry and identifiable risk!
(i.e. diuretic usage, loss of GI tract fluids, etc.).

Front 2

simple problems

Back 2

-Loss of a single electrolyte in a person with normal regulatory mechanisms and organ system function

Front 3

Water

Back 3

~60% of body wt in adult males, 50% in adult females
-TBW is affected by age and habitus (dec with age and decreasing LBM)
-Obese Male: TBW = 50%, female 42%
-Lean Male : TBW = 70%, female 60%
-Average infant 77%, average elderly 52%

Front 4

where is the water?

Back 4

~2/3 intracellular
~1/3 extracellular (mostly interstitial-16%; intravascular-4%)
-compartments are separated by semi-perm membranes

Front 5

Intracellular

Back 5

1. K+
2. HPO4
3. SO4
4. inorganic acids

Front 6

Extracellular

Back 6

1. Na+
2. Ca++
3. Cl-
4. HCO3-

Front 7

how to measure electrolytes

Back 7

-unit is milliequivalent (related to # of particles and valence:

meq/l = mg/dl x 10/ (molec. wt) x valence
-move to maintain electrical neutrality and across concentration gradients

Front 8

forces of movement and units of measure: water

Back 8

-moves by hydrostatic pressure and osmosis (# of particles in compartment)
-estimate of osmolarity:
2 [Na] + BUN/2.8 + glucose/18
-1 liter of water weights 1 kg

Front 9

osmolality

Back 9

-The concentration of an osmotic solution especially when measured in osmols or milliosmols per 1000 grams of solvent.

Front 10

osmolarity

Back 10

-The concentration of an osmotic solution especially when measured in osmols or milliosmols per liter of solution.

Front 11

Tonicity

Back 11

-what happens when solution is delivered
1. Isotonic: cell volume unchanged
2. hypertonic: cell shrinks
3. hypotonic: cell swells

Front 12

Normal saline

Back 12

-(.9% NaCl) is isosmotic and isotonic
-same concentration as serum, and Na+ does not easily cross cell membrane
-administering 1 liter of NS raises blood volume by about 300ml (~6%)

Front 13

D5W

Back 13

-(5% dextrose in water) is isosmotic and hypotonic
-same concentration as serum when delivered, but glucose with slowly taken up across cell membrane with water
-administering 1 liter of D5W raises blood vol by about 75-100ml (~2%)

Front 14

capillary dynamics

Back 14

-determines vascular/cellular exchange
-key factors include:
1. capillary integrity and pressure
2. interstitial fluid pressure
3. plasma colloid osmotic pressure
4. interstitial colloid osmotic pressure
-disruption of balance leads to EDEMA
-slide 21

Front 15

Causes of edema

Back 15

1. high cap pressure (CHF)
2. low plasma protein (liver disease)
-albumin <3 --> dependent edema
-albumin <2 --> generalized edema
3. lymphatic blockage (cancer)
4. inc cap porosity (shock, burns)

Front 16

rating scale for edema

Back 16

slide 25

Front 17

key body systems that maintain balance

Back 17

1. cardiac
2. GI
3. respiratory
4. endocrine
-NOT JUST RENAL!

Front 18

Cardiac

Back 18

-20% of CO goes to kidneys
-decreased CO leads to dec GFR
-decreased GFR means dec Na+ delivery

Front 19

respiratory

Back 19

-water balance
-acid/base balance
-renin-angiotensin system

Front 20

endocrine

Back 20

-ADH: water
-Aldosterone: Na/K+
-PTH: Ca/PO4, (Mg)
-Calcitonin: Ca/PO4, (Mg)

Front 21

Tonicity

Back 21

-what happens when solution is delivered
1. Isotonic: cell volume unchanged
2. hypertonic: cell shrinks
3. hypotonic: cell swells

Front 22

Normal saline

Back 22

-(.9% NaCl) is isosmotic and isotonic
-same concentration as serum, and Na+ does not easily cross cell membrane
-administering 1 liter of NS raises blood volume by about 300ml (~6%)

Front 23

D5W

Back 23

-(5% dextrose in water) is isosmotic and hypotonic
-same concentration as serum when delivered, but glucose with slowly taken up across cell membrane with water
-administering 1 liter of D5W raises blood vol by about 75-100ml (~2%)

Front 24

capillary dynamics

Back 24

-determines vascular/cellular exchange
-key factors include:
1. capillary integrity and pressure
2. interstitial fluid pressure
3. plasma colloid osmotic pressure
4. interstitial colloid osmotic pressure
-disruption of balance leads to EDEMA
-slide 21

Front 25

Causes of edema

Back 25

1. high cap pressure (CHF)
2. low plasma protein (liver disease)
-albumin <3 --> dependent edema
-albumin <2 --> generalized edema
3. lymphatic blockage (cancer)
4. inc cap porosity (shock, burns)

Front 26

rating scale for edema

Back 26

slide 25

Front 27

key body systems that maintain balance

Back 27

1. cardiac
2. GI
3. respiratory
4. endocrine
-NOT JUST RENAL!

Front 28

Cardiac

Back 28

-20% of CO goes to kidneys
-decreased CO leads to dec GFR
-decreased GFR means dec Na+ delivery

Front 29

respiratory

Back 29

-water balance
-acid/base balance
-renin-angiotensin system

Front 30

endocrine

Back 30

-ADH: water
-Aldosterone: Na/K+
-PTH: Ca/PO4, (Mg)
-Calcitonin: Ca/PO4, (Mg)

Front 31

GI tract: water

Back 31

-intake; secretion --> 9 liters!
-absorption

Front 32

GI content: electrolytes

Back 32

-slide 33

Front 33

the kidney

Back 33

~20% of CO goes to kidneys, and 20% of that becomes filtrate
-nml GFR is about 120ml/min (180 1/d)
-only ~1% of everything that is filtered is excreted in the urine

Front 34

Categories of problems

Back 34

1. ECF volume disturbances (sodium and water)
-vol depletion
-volume excess
2. osmolality disturbances
-hypotonic disorders (water excess)
-hypertonic disorders (water deficit)
3. disturbances of individuals electrolytes

Front 35

causes of absolute and relative hypovolemia

Back 35

-slide 42