Fluid and Blood Therapy Flashcards
Roles of Fluids in the Human Body
transport, temperature regulation, maintain internal environment
Transport
deliver oxygen and nutrients to cells and remove waste materials
Temperature and Regulation
blood circulation to the skin and sweating increase heat dissipation, helping to keep the body at a constant temperature
Maintain Internal Environment
body fluid properties are kept constant to maintain an efficient metabolism
Total Body Fluid composition
18% protein
60% water
16% fat
6% minerals etc
TBF composition of newborn
80%
TBF composition of toddler
70%
TBF composition of child
65%
TBF composition of Adult man
60%
TBF composition of adult woman
55%
TBF composition of seniors
50-55%
TBW compartments of females
45% solids
55% fluids
TBW compartments of males
40% solids
60% fluids
Fluids are composed of
2/3 intracellular fluid
1/3 extracellular fluid
Extracellular fluids is composed of
75% interstitial fluid
25% plasma
Calculate the amount of water in each compartment for a 100kg male
TBW= 60% ICF= 2/3 of TBW ECF= 1/3 of TBW Interstitial fluid 75% of ECF Plasma 25% of ECF
Why is there more fluid in the interstitial compartment than the plasma?
plasma and proteins + reservoir
Electrolytes found in the ICF
Magnesium
Potassium
Phosphate
Proteins
Electrolytes in the ECF
Chloride sodium calcium bicarb glucose
Cell membrane transport
no extra energy required
passive (simple facilitate)
osmosis
Passive diffusion is
simple or facilitate
Simple diffusion
doesn’t have a carrier
Facilitated diffusion
has a carrier
Osmosis is the
simple diffusion of water
from a high concentration of water to a low concentration of water across a semi permeable membrane
Is the fluid inside the RBCs considered ICF or ECF?
ICF
Pc
capillary pressure
hydrostatic pressure
pushes on the capillary wall
Pi
interstitial fluid pressure
the push of fluid into the capillary
Pic
plasma colloid osmotic pressure
the pull into the capillary (albumin)
Pii
interstitial fluid colloid osmotic pressure
the release of fluid into the interstitial space
Osmolality
number of osmoles of solute in a kilogram of solvent
Osmolarity
number of osmoles of solute in a liter of solution
osmotic pressure
pressure needed to stop osmosis
osmotic pressure is dependent on
number of molecules
the size of the molecules does not affect the osmotic pressure
P=n/v
number of solutes, v= volume
osmole
the osmosis caused by a mole
millimole
molecular weight in milligrams
what unit do we use
mOsm
Mole
standard unit for measuring large quanities of very small atoms, molecules or particles
Avogardo’s number
6.022x 10^23
the number of atoms, molecules or particles in a mole is the same for all substances
omostic pressure depends
number of molecules not the mass
Calculate osmolality
2 x Na +glucose/18 +BUN/2.8
Normal Plasma Osmolality
290 mOsm/L
Homeostasis
Osm IVF =Osm ISF= Osm ICF= 290 mOsm/L
TOnicity
the ability of the combined effect of all the solutes to generate an osmotic driving force that causes water movement
- only includes the effect osmoles
Hypertonic Solution
increased plasma osmolality above the normal level
>295mOsm/L
Isotonic Solution
normal plasma osmolality
290mOsm/L
Hypotonic Solution
decreased plasma osmolality below the normal level
< 275mOsm/L
Sodium
most abundant electrolyte in ECF
responsible for most of the osmotic activity of the osmotic activity of the ECF
Gain of Na+–> gain of H20
Loss of Na+—> Loss of H20
ECF [Na] > ICF [Na+] d/t the NaK ATPase pump
alterations in ECF [Na] greatly affects the movement of water across the cell membrane
Serum Na
Sernum Na ~ TBNa/TBW
Fluid Disorders
isotonic fluid disorders
hypotonic fluid disorders
hypertonic fluid disorders
Isotonic fluid disorders
isotonic loss of fluid
isotonic gain of flui
Hypotonic fluid disorders
hypertonic loss of Na
gain of pure water
hypotonic gain of Na
Hypertonic fluid disorders
hypotonic loss of Na
loss of pure water
hypertonic gain of Na
hyperglycemia
isotonic loss or gain of fluid
no change to serum Na
no osmotic gradient
no water shift across membranes
no change in ICF compartment
isotonic loss of fluid example
hemorrhage
Hemorrhage is
an ECF volume depletion Serum Na normal serum osmolality stays normal ICF normal Administer isotonic fluid
Isotonic gain of fluid example
excessive gain of isotonic fluid
Excessive gain of isotonic fluid
ECF volume overload
ECF increase
Serum na/osmolality/ICF= normal
hypotonic fluid disorders
plasma osmolality is low caused by low serum na
osmotic gradient shifts water from ECF to ICF, ICF volume expansion
cellular swelling
Hypertonic loss of Na examples
diuretics (loop, thiazide)
addison’s disease (decrease aldosterone)
21 hydrodxylase deficiency (decrease aldosterone)
Hypertonic loss of Na is
ECF volume depletion
decrease in serum NA, decrease in TBNa/TBW
Decreases ECF, Serum Na, Serum osmolality, increase in ICF
Gain of Pure water example
SIADH
Gain of Pure Water
decrease serum Na TBNa / increased TBW ECF increase Serum Na decrease Serum osmolality decrease ICF increase
Treatment of gaining of pure water
restrict water
treat underlying problem
Gain of hypotonic solution example
absorption of electrolyte- free irrigation solution (TURP or endometrial ablation)
Gain of hypotonic solution
decrease serum Na = TBNa/increase in TBW
increase in ECF
decrease in serum Na, osmolality
increase in ICF
S/S of gain of hypotonic solution
seizures, pulmonary edema, difficulty ventilating, cerebral edema
Treatment of gain of hypotonic solution
diuresis
3% NS
Hypotonic Gain of Na Example
Overload states
cirrhotic, nephrotic, CHF
Hypotonic Gain of Na
decrease serum Na= increase TBNa/increased TBW
ECF increased
decrease serum Na and serum osmolality
increased ICF
S/S of hypotonic gain of NA
dependent pitting edema cavity effusions (ascites) SOB increase Body weight mental status changes
Treatment of hypotonic gain of Na
restrict salt and water
diuretic
Hypertonic Fluid Disorders
plasma osmolality is high caused by a high serum Na or glucose osmotic gradient water shifts from ICF to ECF ICF volume contracts (cell shrinks)
Hypotonic loss of Na examples
sweating, osmotic diarrhea, osmotic diuresis, vomiting
Hypotonic loss of Na
increase in serum Na= decrease in TBNa/decrease TBW
ECF and ICF decrease
Serum Na and Osmolality increase
S/S of hypotonic loss of Na
dry skin, mucuous membranes
dizzy confusion
mental status changes
increase HR
Treatment of hypotonic loss of Na
administer isotonic fluid (to maintain BP) then switch to hypotonic fluid (0.45% NS)
Loss of Pure Water Example
Diabetes Insipidus
excessive water evaporation off the skin surface (fever, burns, insensible fluid loss)
Loss of Pure Water
increase serum Na = TBNa/decreased TBW
ECF decreased ICF decreased
Increase in Serum Na and osmolality
Loss of Pure water s/s
confusion, drowsiness mental status changes
Treatment of Pure water
administer water D5W
treat underlying problem
Hypertonic Gain of Na example
NaHCO3 infusion
infusion of hypertonic saline, antibiotics that contain Na, sodium modeling in hemodialysis
Hypertonic Gain of Na
increase ECF
Decrease ICF
Increase serum Na and osmolality
S/S in hypertonic gain of Na
mental status
Treatment of hypertonic gain of Na
stop the infusion
Hyperglycemia Example
Diabetic Ketoacidosis (type 1 DM) Hyperosmolar non-ketotic coma (type 2 DM)
Hyperglycemia
decrease serum Na = decrease TBna/ TBW
decrease ECF and ICF
decrease serum Na
increase Osmolality
S/S of hyperglycemia
mental status changes
diabetic coma
Treatment of hyperglycemia
treat underlying cause
Alterations in Fluid Balance Preoperative
burns vomitting diarrhea fever gastric suction bowel prep
Alterations in Fluid Balance intraoperative
hemorrhage
evaporative loss
third spacing (manipulation of tissues)
hypo-osmolar irrigation (TURP, endometrial ablation)
Alterations in Fluid balance anesthesia
vasodilation
release of ADH
increase evaporative loss from ventilation
mobilization of third space fluids on POD #3
ADH
nonapeptide synthesized in hypothalamus
released in response to stress
MOA- reabsorption on the collecting ducts in kidneys causing water retention
potential to offset the hypovolemic effect of fasting
Is urine output a valid indicator of perioperative volume status?
since UOP can be affected by multiple factors it is not a sensitive indicator of circulating blood volume
recommendation- isolated low UO should not trigger fluid therapy and extensive diagonstic efforts
Goal Directed Fluid therapy
maximizing cardiac flow parameters as a surrogate for oxygen delivery improves outcomes
Primary objective of periop fluid therapy
maintenance of normovolemia in order to maintain adequate tissue perfusion
Fluid challenge
CO will usually increase in response to a fluid challenge
Traditional Method of Fluid therapy
calculate fluid requirements for
surgical loss deficit and maintenance
Hourly Maintenance Fluid Requirements
4 mg/kg/hr 0-10kg
2mg/kg/hr 11-20kg
1mg/kg/hr 21+ kg
NPO Deficit
hourly maintenance requirement x # of hours NPO
Minimal surgical loss additional fluid requirements
0-2ml/kg
short superficial procedure
Moderate surgical loss additional fluid requirements
uncomplicated intraabdominal or orthopedic procedure
2-4ml/kg
severe surgical loss additional fluid requirement
prolonged highly invasive procedure
4-8ml/kg
D5W
hypotonic solution
has little place perioperatively
cause free water intoxication adn hyponatremia
additional calorie but also can cause hyperglycemia
Evaporative Loss and 3rd Space Loss
evaporative loss related directly to surface area of surgical wound and duration of exposure
3rd space loss is due to fluid shifts and intravascular volume deficit caused by re-distribution of fluids
Calculating 3rd Space (need to know)
type of procedure
degree of exposure
amount of surgical manipulation
