fluids and blood products Flashcards
what percent of adults is water? infants?
60% adults
80% infants
total body water (TBW)
what are the compartments of TBW and their percentages
- intracellular fluid (67%)
- extracellular fluid (33%)
2a. interstitial fluid (25% of ECF)
2b. plasma (8% of ECF)
do iv fluids directly change ECF or ICF
IV fluids directly change ECF which indirectly affect ICF
compartments of ECF
interstitial fluid (electrolytes)
blood (plasma and cells)
- plasma (electrolytes)
- plasma proteins
- RBCs
- platelets
- WBCs
how is distribution of fluid in ECF (between plasma and IF) determined
bulk flow (starling forces)
what are the 2 main pressures in bulk flow
hydrostatic pressure (blood pressure): out
colloid osmotic pressure (from plasma proteins): in
causes of water imbalance on the body
retention (edema, hypertension - diuretics)
dehydration (fixed with IV fluids)
reasons for IV fluid administration
- dehydration
- electrolyte imbalances
- blood compartment deficiencies
- nutrition
3 types of IV fluids
- crystalloids
- colloids
- blood and blood products
crystalloids
water + small fully dissolved molecules
- electrolytes (Na, K, Cl)
- molecules (glucose, lactate)
no proteins or large molecules
what does saline consist of
sodium chloride
what is normal saline
the same concentration of sodium chloride as in the body (~154 mmol/L)
- 0.9% sodium chloride
- 0.9gNaCl/100mL
what is normosol
NaCl, K, more things in it, more closely mimics. ECF composition (expensive)
half normal saline
0.45% sodium chloride (hypotonic)
what is normal cell osmolarity
300mOsm/L
isotonic solution
IF = 300mOsm/L (fluid not moving)
hypotonic solution
IF = 290 mOsm/L (water follows concentration gradient and enters cell, cell swells)
hypertonic solution
IF = 330 mOsm/L (water leaves cell, cell shrinks)
crystalloids examples
- normal saline (0.9%NaCl)
- half NS (0.45% NaCl)
- hypertonic saline (3% NaCl)
- lactated ringer’s
- normosol/plasmalyte
- D5W, dextrose 5% in water (300 mOsm/L, give water with glucose, body uses the glucose and leaves the water so it acts like a hypotonic solution)
uses of crystalloids
treating dehydration
- from volume loss (diarrhea, vomiting
maintain fluids
- compensate for fluid loss (NS)
- replace fluids (NS)
- manage specific fluid and electrolyte disturbances (ringer’s lactate)
- promote urinary flow (NS)
- expand plasma volume (3% NaCl)
isotonic loss
lose water and particles (less volume but same concentration)
- normal saline given (isotonic fluid)
- ex) blood loss, vomit, diarrhea
hypotonic loss
lose more water than particles (less volume and more concentrated ECF)
- hypotonic solution given to balance hypertonic ECF (half normal saline)
- hypertonic contraction
- ex) sweating
crystalloids indications
- acute liver failure
- acute nephrosis
- burns
- hypovolemic shock
- renal dialysis
crystalloids adverse effects
- edema (peripheral or pulmonary - fluid overload too quickly, fluid in interstitial spaces out of blood)
- may dilute plasma proteins (long term use)
- effects may be short lived
what do colloids do
enhance colloid osmotic pressure
- move fluid from interstitial compartment to plasma compartment
- plasma volume expanders (restore BP)
- initiate diuresis (ex. remove ascites in pt with portal hypertension)
colloids stay in blood (too big to leave capillaries)
hypertonic crystalloids can also be plasma volume expanders
colloids examples
- dextran 40 or 70 (big glucose polymers)
- hetastarch/hydroxyethyl starch
- modified gelatin
- albumin (from human donors)