Fluids&Electrolytes plus Flashcards
the ability to maintain internal equilibrium by adjusting physiological processes
homeostasis
[LeMone 186]
what must remain within a narrow range in intracellular and extracellular spaces to maintain life and health? (3 things)
fluid volume
electrolyte compostition
pH
[LeMone 186]
- fluid found within body cells
- constitutes 2/3 of body fluids in adults
- contains solutes
intracellular
[BOB518]
- fluid found between cells
- constitutes 1/3 of body fluids in adults
- subdivided into two compartments (intravascular and interstitial)
extracellular
[BOB518]
what are the primary cations of intracellular fluid?
potassium and magnesium
[BOB518]
what are the primary anions of intracellular fluid?
phosphate and sulfate
[BOB518]
what are the principle electrolytes of extracellular fluid?
sodium, chloride and bicarbonate
[BOB518]
what are examples of cations?
sodium, magnesium, potassium, calcium
[BOB518]
electrolytes that carry a positive charge
cations
[BOB518, LeMone187]
electrolytes that carry a negative charge
anions
[BOB518, LeMone187]
what are examples of anions?
chloride, bicarbonate, phosphate, sulfate
[BOB518]
does the proportion of body water increase or decrease with age?
decreases
[BOB518]
what is included in extracellular fluid ?
plasma lymph transcellular cerebrospinal pericardial pancreatic pleural intraocular bliliary peritoneal synovial [BOB518]
what is the average fluid intake and output over a 24 hr period?
2500mL
[LeMone187]
what is the average daily urine output of an adult?
1500mL
[LeMone187]
where does insensible water loss occur?
skin, lungs, feces
[LeMone187]
what are the purposes of electrolytes?
-assist with regulation or water balance
-regulating/maintaining acid-base balance
-contribute to enzyme reactions
-essential for neuromuscular activity
[LeMone187]
what is another name for intravascular fluid?
plasma
[LeMone187]
where is intravascular fluid contained?
within arteries, veins and capillaries
[LeMone187]
what are the primary electrolytes of intracellular fluid?
potassium magnesium phosphate (also contains glucose and oxygen) [LeMone188]
what are the primary electrolytes of extracellular fluid?
sodium chloride bicarbonate (low levels of potassium) [LeMone188]
what electrolyte is only present in small amounts in extracellular fluid?
potassium
[LeMone188]
why are high levels of sodium important in extracellular fluid?
to regulate body fluid volume
[LeMone188]
what is the normal range in the plasma for sodium?
135-145 mEq/L
[LeMone188]
what is the normal range in the plasma for chloride?
98- 106 mEq/L
[LeMone188]
what is the normal range in the plasma for bicarbonate (HCO3)?
22 - 26 mEq/L
[LeMone188]
what is the normal range in the plasma for calcium?
8.5 - 10.5 mEq/dL
[LeMone188]
what is the normal range in the plasma for potassium?
3.5 - 5 mEq/L
[LeMone188]
what is the normal range in the plasma for phosphate?
2.4-4.5 mEq/L
[LeMone188]
what is the normal range in the plasma for magnesium?
1.56 - 2.65mEq/dL
[LeMone188]
what is the normal range in the plasma for serum osmality?
275 - 295 mOsm/kg
[LeMone188]
the process by which water moves across a selectively permeable membrane from an area of lower solute concentration to an area of higher solute concentration (continues until the concentration is equal on both sides)
osmosis
[LeMone189]
- the concentration of a solution
- refers to the number of solutes per kilogram of water (by weight)
osmolality
[LeMone189]
what is the average serum sodium concentration?
142 mEq/mL
*serum osmolality may be estimated by doubling serum sodium concentration
[LeMone189]
how much of a healthy adults body weight is water?
60%
[f/e ppt]
the effect a solution’s osmotic pressure has on water movement across the cell membrane of cells within that solution (two solutions separated by a semipermeable membrane, aka the cell membrane)
tonicity
[LeMone189]
- a solution that has the same concentration of solutes as plasma
- cells placed within this solution will neither shrink nor swell because there is no net gain or loss of water within the cell, so no change in cell volume
isotonic solution
[LeMone189]
- a solution that has a greater concentration of solutes than plasma
- in the presence of a greater concentration of solutes, water is drawn out of the cell (trying to balance the outer with the inner) and this causes the cell to shrink
hypertonic solution
[LeMone189]
- a solution that has a lower concentration of solutes than plasma
- in the presence of a lower concentration of solutes, water is drawn into the cell (trying to balance the outer with the inner) and this causes the cell to swell (and possibly rupture)
hypotonic solution
[LeMone189]
what is the sodium content of normal saline?
0.9%
the process by which solute molecules move from an area of high solute concentration to an area of low solute concentration to become equally distributed
diffusion
[LeMone189]
what are the two types of diffusion?
simple diffusion and facilitated diffusion
[LeMone189]
the process by which water and dissolved substances (solutes) move from an area of high hydrostatic pressure to an area of low hydrostatic pressure
filtration
[LeMone189]
what is the equation for calculating BMI?
BMI = [mass (kg)] / [height (m)]2
what is the equation for calculating BSA?
BSA = sq rt [height (in) x weight (lbs) / 3131]
or
BSA = sq rt [height (cm) x weight (kg) / 3600]
*measured in m2
what unit is BSA measured in?
meters squared (m2)
the pressure a liquid exerts on the sides of the container that holds it
hydrostatic pressure
[B&S1560]
- allows molecules to move across cell membranes and epithelial membranes against a concentration gradient
- requires energy (ATP) and a carrier mechanism to maintain a higher concentration of a substance on one side of the membrane than on the other
active transport
*ie sodium potassium pump
[LeMone190]
component of a solution that can dissolve a solute
solvent
component of a solution that is dissolved in solvent
solute
what results when a solute is dissolved in a solvent?
a solution
where is your body’s thirst regulator?
hypothalmus
referring to the loss of water alone from the body
dehydration
[LeMone193]
decrease in intravascular, interstitial and/or intracellular fluid in the body
fluid volume deficit
[LeMone193]
what is the most common cause of fluid volume deficit?
excessive loss of GI fluids from: vomitting diarrhea GI suctioning intestinal fistulas intestinal drainage [LeMone193]
what happens to the serum sodium level when both water and electrolytes are lost?
it remains normal (though other levels may fall)
[LeMone193]
a shift of fluid from the vascular space into an area where it is not available to support normal physiological processes
third spacing
what is the normal specific gravity of urine?
1.010 to 1.025
Electrolytes:
Neuromuscular: contraction of skeletal and smooth muscles, transmission and conduction of nerve impulses
Cardiac: contraction of myocardium, nerve conduction
Cellular: regulation of osmolality in INTRAcellular fluid, enzyme reaction for cellular energy production
Potassium
Electrolytes:
Neuromuscular: sodium pump
Body fluid: regulator of body fluids, largely responsible for osmolality of body fluids
Cellular: Na/K pump, enzyme activity
Acid base: regulation of acid base balance (combines readily with bicarbonate or chloride to regulate balance)
Sodium
Electrolytes:
Osmolality of EXTRAcellular fluid
Body water balance: as sodium is retained, this is retained as we’ll
Gastric juice: combines with H to create gastric acid
Chloride
Electrolytes:
Neuromuscular: contraction of skeletal muscles, transmission of nerve impulses
Cardiac: contraction of myocardium
Cellular: helps with normal maintenance of cellular permeability, also assists with coagulation, formation of bones & teeth
Calcium
Electrolytes:
Neuromuscular: transmission in CNS
Cardiac: contraction of myocardium
Cellular: activates enzymes for carb and protein metabolism, responsible for transport of Na & K across cell membranes
(deficits are often accompanied by Ca or K deficits)
Magnesium
Electrolytes:
Neuromuscular: normal nerve and muscle activity, contributes to bones and teeth
Cellular: formations of ATP, metabolization of carbs, proteins, fats, big part of acid base balance in body fluids
Phosphate
Charged ions capable of conduction electricity, in various concentrations and combinations.
Electrolytes
- test for observing if a client has low calcium levels
- inflate a BP cuff on a patients arm higher than their normal systolic pressure and wait 3 min > a positive sign is indicated when the clients hand displays a characteristic posture (metacarpophalangeal joints are flexed, the interphalangeal joints of the fingers and thumb are extended and the thumb adopts a posture of opposition)
Trousseau sign
- test for observing if a client has low calcium levels
- when the facial nerve is tapped at the angle of the jaw the facial muscles on that side of the face will momentarily contract (usually around the nose and mouth)
Chvostek sign
- involuntary reaction that can be seen with low magnesium levels
- a positive sign is seen when scraping the bottom of the foot from the heel up to the ball of the foot and the big toe points up while the other toes fan out
Babinski’s sign