Fluid Balance Flashcards
2 basic functions of fluid
- Provide transportation of nutrients to cell and waste from cell
- Provides medium for chemical reactions
Composition of water in the body
Adult male 60%
Adult female 50%
Infants (under 2) 60-80%
Elderly (over 45) 45-55%
Why do females have lower body composition of water than males?
females have higher composition of body fat and fat cells contain very little water
Why do the elderly have a lower composition of water?
muscle atrophy
How does the body lose fluid?
kidneys, GI tract, lungs, skin
How much fluid is lost through the kidneys daily?
about 1500 cc daily
How much fluid is lost through the GI tract daily?
150-200 cc daily
8-10 liters is secreted but most is reabsorbed
How much fluid is lost through the lungs daily?
300-400 cc daily
How much fluid is lost through the skin daily?
400-500 cc daily
Sensible & insensible
What is sensible fluid loss through the skin?
sweating
What is insensible fluid loss through the skin?
evaporation
How do we replenish fluids?
liquids & fluids
How much fluid do we need in 24 hours?
30 cc/kg
How is food replenished via food?
Meats, fruits and veggies contain 60-97% water
Oxidation of carbohydrates, fats or proteins via TCA (Krebs) Cycle–10 cc of water for every 100 calories
Where is the majority of water in children?
interstitial space
Do adults of children have a greater metabolic rate?
children
daily fluid needs for children
Premature 50-70 ml/kg Newborn 80-100 ml/kg Newborn-1 year 150 ml/kg 1-2 years 100 ml/kg 2-4 years 90ml/kg 4-10 years 50-70 ml/kg > 10 years 40 ml/kg
Volume of fluid in intracellular fluid compartments
25 liters
Volume of fluid in extracellular fluid compartments
15 liters
3 extracellular fluid compartments
interstitial
intravascular
transcellular
What is interstitial fluid?
fluid surrounding the cell
Volume of interstitial fluid
8 liters
What is intravascular fluid?
fluid within blood vessels
Volume of intravascular fluid
5-6 liters
What is transcellular fluid?
fluid secreted by epithelial cells
examples of transcellular fluid
CSF, pericardial fluid, pleural fluid, synovial fluid, intraocular fluid, digestive secretions
Volume of transcellular fluid
1 liter
first spacing
normal fluid distribution
second spacing
interstitial edema
third spacing
fluid in areas with little or no fluid normally
examples of third spacing
ascites, pleural effusion, pericardial effusion
transport processes that effect movement of water and solutes
diffusion
active transport
flitration
osmosis
examples of solutes that move by facilitated diffusion
insulin
glucose
example of active transport
Na+/K+ pump
what type of transport id dependent on hydrostatic pressure?
filtration
Why are diabetics constantly thirsty and frequently urinate?
glucose has strong osmotic pull
Osmolarity of water
280-294 mOsm/kg
tonicity
ability of particles to affect the movement of water
fluid movement in isotonic solutions
no net movement
fluid movement in hypotonic solutions
fluid moves into cell (cells can burst)
fluid movement in hypertonic solutions
fluid moves out of cell (cells can shrivel)
locations of volume receptors (baroreceptors)
carotid sinuses, aortic arch, cardiac atria & renal vessles
what type of IV fluids can diffuse through the capillary wall
crystalloid solutions
what type of IV fluids cannnot pass through capillary wall
colloid solutions
what are colloid solutions used to treat
severe deficit or shock
what type of IV fluids increase osmotic pressure in vascular space
colloid solutions
what type of IV fluids are plasma or volume expanders
colloid solutions
what compartment(s) expand with hypotonic solutions?
ECF and ICF
what compartment(s) expand with isotonic solutions
ECF only
what tonicity is best for patients with extracellular fluid deficit?
isotonic solutions
how do hypertonic solutions work?
by raising osmolarity of ECF and expanding it; draw water out of cell into ECF