40 Fluids Flashcards
Osmosis
water (the solvent) moves from an area of LESSER solute concentration to GREATER solute concentration
Diffusion
the tendency of solutes to move freely throughout a solvent
- Solute moves fr area of HIGH concentration to LOW concentration
- “Coasting downhill”
Active Transport
a process that requires energy for the movement of substances through a cell membrane against the concentration gradient
-“Pumping uphill”
Capillary Filtration
passage of fluid through a permeable membrane
-from the force of blood pushing against the wall of capillaries
ISOTONIC IV
Has a concentration equal to ICF
- Cells will neither shrink nor swell with fluid movement
- Used for hypovolemia, burns, fluid loss fr GI tract
ex) normal saline soln
HYPERTONIC IV
Tonicity is greater than ICF
- Draws water out of cells + into highly concentrated ECF
- Cells will SHRINK
- Used as basic fluid for maintenance needs and for hypernatremia
ex) dehydration or rapidly infused hypertonic fluid, 3% saline, 50% dextrose
HYPOTONIC IV
Tonicity is less than ICF
- Osmotic pressure draws water into cells from ECF
- Cells SWELL
- Used t treat SIADH, to treat hypovolemia if plasma expander is not available
ex) half-normal saline soln
INTRACELLULAR FLUID (ICF)
fluid within cells
- 70% of total body water
- 40% of body weight
EXTRACELLULAR FLUID (ECF)
all fluid outside of cells
30%of total body water
20% of body weight
Easily lost from the body than ICF
2 parts of ECF
intravascular and interstitial
INTRAVASCULAR COMPARTMENT
- plasma, liquid component of blood
INTERSTITIAL COMPARTMENT
- fluid that surrounds tissue cells and includes lymph
infants vs elderly
higher risk of fluid imbalance
Infants - carry more total body fluid + ECF than adults
Elderly - increased fat cells and decreased muscle
Therefore, lower total body fluid
death range of pH
too acidic<6.9-7.8
maintenance of acid-base balance reflects homeostatic functions of ___
normal cellular metabolism
if pH is too acidic, proteins will ____
get denatured
normal pH
7.35-7.45
normal PaCO2
36-44 mmHg
normal HCO3-
22-26 mEq/L
useful indicators of acid-base status of ECF
arterial blood gas [ABG]
PaCO3 indicates ___
how effectively the respiratory sytm is excreting carbonic acid
lung/respiratory function
HCO3- indicates ___
effectiveness of renal regulation of metabolic acids
- excess or deficit of metabolic acids
- renal/metbolic function
3 major systems to regulate acid-base
1 buffer
2 respiratory sytm
3 renal sytm
first line of defense against pH changes in all body fluids
Bicarbonate Buffer system
chemicals that help control pH of body fluids
1 Bicarbonate ions [HCO3-]
2 Carbonic acid [H2CO3]
Bicarbonate Ions
HCO3-
basic
-takes up H when fluid is too acidic
Carbonic Acid
H2CO3
weak acid
-release H ions when fluid is too alkaline
normal ratio of HCO3-:H2CO3
20:1
