Managing Clients with Fluid Volume Disturbances
Parenteral Fluid Therapy (IV therapy)
What’s the purpose??
IV Fluids
Crystalloids - IV fluids containing varying concentrations of electrolytes and lack large proteins and molecules found in colloids.
Colloids - IV fluids containing large proteins and molecules that tend to stay in the vascular space (blood vessels).
Blood and Blood Products
Parenteral Nutrition
IV Fluids http://www.modernmedicine.com/urology-times/news/iv-fluids-do-you-know-whats-hanging-and-why
Crystalloids
contain small molecules that flow easily across semipermeable membranes, allowing for transfer from the bloodstream into the cells and body tissues may increase fluid volume in both the interstitial and intravascular spaces
Isotonic, Hypertonic, Hypotonic
Colloids contain large molecules that don't pass through semipermeable membranes remain in the intravascular compartment expand intravascular volume by drawing fluid from extravascular spaces via their higher oncotic pressure
Osmolarity
# of milliosmoles per liter of solution
Plasma osmolality = 270-300 mOsm/L
Crystalloids are grouped according to their osmolarity
Isotonic 240-340mOsm/L
Hypertonic > 340mOsm/L
Hypotonic < 240 mOsm/L
Isotonic Fluids
Concentration of dissolved particles is similar to that of plasma
Osmolality of 250 to 375 mOsm/L
Fluid in each compartment remains within its compartment (no shift occurs) and cells neither shrink nor swell
Remain within the extracellular fluid compartment and are distributed between the intravascular and interstitial spaces, thus increasing intravascular volume
Types of isotonic solutions include:
0.9% sodium chloride (0.9% NaCl) lactated Ringer's solution
5% dextrose in water (D5W)
Nursing Considerations:
Hypertonic Fluids
Have a higher tonicity or solute concentration, causing an unequal pressure gradient between the inside and outside of the cells
Have an osmolarity of 375 mOsm/L or higher
The osmotic pressure gradient draws water out of the intracellular space, increasing extracellular fluid volume. Because of this property, hypertonic solutions are used as volume expanders.
Types of Hypertonic Solutions:
D51/2NS, D5NS
3% or 5% NS
Nursing Considerations:
Hypotonic Fluids
Compared with intracellular fluid & isotonic solutions, hypotonic solutions have a lower concentration, or tonicity, of solutes (electrolytes).
Osmolality less than 250 mOsm/L
Infusing a hypotonic solution causes an unequal solute concentration among the fluid compartments.
Lowers the serum osmolality within the vascular space, causing fluid to shift from the intravascular space to both the intracellular and interstitial spaces
Types of Hypotonic fluids
0.25%
0.45%
D5W
Nursing Considerations
Colloids
Contain molecules too large to pass through semipermeable membranes
Also known as volume expanders or plasma expanders
Require administration of less total volume compared with crystalloids
Have a longer duration of action than crystalloids because the molecules remain within the intravascular space longer
Effects can last for several days if capillary wall linings are intact and working properly
Examples:
Albumin
Dextrans
Nursing Considerations
Fluid Volume Disturbances
Hypovolemia
Loss of extracellular fluid volume exceeds the intake of fluid
Water and electrolytes are lost in the same proportion as they exist in body fluids so that the ratio of serum electrolytes to water remains the same
Fluid volume deficit
Includes fluid & electrolytes
Risk factors
Abnormal fluid loss like vomiting, diarrhea, GI suctioning, sweating
Decreased fluid intake as in nausea or inability to gain access to fluids
Diabetes insipidus
Adrenal insufficiency
Osmotic diuresis
Hemorrhage
coma
Clinical Manifestations of Hypovolemia – can occur rapidly and can
