Types of Fluids

Types of fluids
Isotonic, Hypotonic, Hypertonic

1. 1

Intravenous therapy
Intravenous therapy or IV therapy is the infusion of liquid substances directly into a vein.
Or
Intravenous therapy, also referred to as ‘IV therapy’, constitutes the administration of liquid
substances directly into a vein and the general circulation through venepuncture (Mosby
1998).
• Replace fluids and replace imbalances.
• Maintain fluid, electrolyte and acid-base balance.
• Administer blood and blood products.
• Administer medication.
• Provide parenteral nutrition.
• Monitor cardiac function.
• Immediate results
• To provide avenue for dialysis/apheresis
• To provide avenue for diagnostic testing
• Predictable therapeutic effects
• There are more than 200 types of commercially prepared IV fluids

PRINCIPLES USED FOR MOVEMENT OF FLUID IN AND OUT OF
CELL ARE (OSMOSIS and DIFFUSION)









• In Osmosis,
• Fluid moves passively
from areas with more
fluid to areas with less
fluid
• FLUID MOVES
• In Diffusion,
• Solutes (particles) move
from an area of high
concentration to an area
of lesser concentration.
• This process mainly occurs
in gases, liquids and
solutions
• PARTICLES MOVE

2. 2

Osmolarity is the measure of solute concentration, defined as the number
of osmoles (Osm) of solute per litre (L) of solution (osmol/L or Osm/L).
The osmolarity of a solution is usually expressed as Osm/L

Osmolarity vs. tonicity
Osmolarity and tonicity are related, but different concepts. Thus, the terms ending in -
osmotic (isosmotic, hyperosmotic, hyposmotic) are not synonymous with the terms ending in -
tonic (isotonic, hypertonic, hypotonic).
The terms are related in that they both compare the solute concentrations of two solutions
separated by a membrane.
The terms are different because osmolarity takes into account the total concentration of
penetrating solutes and non-penetrating solutes, whereas tonicity takes into account the total
concentration of only non-penetrating solutes.
Penetrating solutes can diffuse through the cell membrane, causing momentary changes in
cell volume as the solutes "pull" water molecules with them. Non-penetrating solutes cannot cross
the cell membrane, and therefore osmosis of water must occur for the solutions to
reach equilibrium.
A solution can be both hyperosmotic and isotonic. For example, the intracellular fluid and
extracellular can be hyperosmotic, but isotonic – if the total concentration of solutes in one
compartment is different from that of the other, but one of the ions can cross the membrane,
drawing water with it and thus causing no net change in solution volume.

Functionally, total body water can be divided into two major compartments:

 Extracellular fluid (ECF)
Approximately 80% of extracellular fluid is interstitial, which occupies the microscopic
spaces between cells. Approximately 20% of extracellular fluid is plasma, which is the liquid portion
of blood

 Intracellular fluid (ICF).
This is also known as cytosol and is the fluid within cells.
• Within the body it is essential that substances move around.
• Substances will move from areas of ‘high’ concentration to ‘low’ concentration and a
‘concentration gradient’ will exist between the two.
• No energy is required for these physiological movements as they are described as ‘passive’.
• Movement is facilitated through processes of ‘osmosis or diffusion’.

3. 3

• COLLOIDS
• Always hypertonic

1. Volume expanders
• CRYSTALLOIDS
• Isotonic
• Hypotonic
• Hypertonic


• Crystalloids
Crystalloids Solutions with small molecules that flow easily from the bloodstream into cells
and tissues. A clear aqueous solution of mineral salts and other water–soluble molecules, for
example 5% Dextrose Solution.

Isotonic solutions have a concentration of dissolved particles equal to that of intracellular fluid.
A solution whose osmolarity falls within the range of 250 and 375 mOsm/Litter is considered
isotonic.
• Osmotic pressure is the same both inside and outside the cell.
• Cells neither shrink nor swell with fluid movement.
• Same tonicity as plasma
• Isotonic solution containing electrolytes such as NaCl, KCl, CaCl, and sodium lactate

Hypotonic solutions have less particles than does intracellular fluid. Fluid flows into cells

• Osmotic pressure is greater than that of intracellular fluid. Hypertonic solutions have a large
concentration of solutes (particles).
• Water is drawn from the cells to equalize the concentration, which causes the cells to
shrink.
• Hypotonic solution containing glucose to provide calories for metabolism
• Glucose moves into cells rapidly
• Inappropriate use can cause fluid overload and pulmonary edema

Hypertonic solutions have a greater concentration of dissolved particles than does
intracellular fluid. Fluid is pulled from cells
• Osmotic pressure is less than intracellular fluid
• Water is drawn into the cells from the extracellular fluid causing them to swell

4. 4

• Inappropriate use can result in increased ICP and cardiovascular collapse from volume
depletion.
• May cause blood cells to burst
Isotonic Solutions (250-375 mOsm/L)
EXAMPLES

Action Indications Nursing
Interventions/Concerns
■ 5% dextrose in
water
■ 0.9% sodium
chloride
Solution (Normal
Saline)
■ Ringer’s injection
■ Lactated
Ringer’s
Solution

Will hydrate the
extracellular
compartment; replaces
fluid volume without
disrupting the
intracellular and
interstitial volumes

Treatment of
vascular
dehydration;
replaces sodium
and chloride

• 5% dextrose in water is
isotonic when infused but
becomes hypotonic when
the dextrose has been
metabolized.
• Use cautiously in patients
who are fluid-overloaded or
who would be compromised
if vascular volume would
increase, such as renal and
cardiac patients.



Hypotonic solutions (<250 mOsm/L)
EXAMPLES

ACTION Indications Nursing
Interventions/Concerns
■ 2.5% dextrose in
water
■ 0.25% sodium
chloride solution
■ 0.33% sodium
chloride solution
■ 0.45% sodium
chloride Solution

Will hydrate the cells;
pulls fluid from the
vascular space into
the cellular space

Treatment of
hypertonic
dehydration
• These solutions may further
exaggerate hypotension due
to fluid shifting out of
vascular space.
• Do not administer these
solutions to hypotensive
patients.

Hypertonic Solutions (>375 mOsm/L)
EXAMPLES

Action Indications Nursing
Interventions/Concerns
■ 5% dextrose in
0.45%
sodium chloride
solution
■ 5% dextrose in
0.9%
sodium chloride
solution
■ 5% dextrose in
lactated Ringer’s
solution
■ 10% dextrose in
water
■ 20% dextrose in
water
■ 50% dextrose in
Will draw fluid out of
intracellular space,
leading to increased
extracellular volume
both in vascular and
interstitial space

Treatment of
hypotonic
dehydration;
treatment of
circulatory
collapse; increase
fluid shift from
interstitial space to
vascular space

• These solutions can be very
irritating to veins, so
observing the IV site for
inflammation is imperative.
• May cause circulatory
overload, so these solutions
should be infused slowly to
prevent this in vulnerable
patients.
• May increase serum glucose
in patients with glucose
intolerance, which would
make more frequent glucose
monitoring an important
nursing intervention

5. 5

water

• 0.9% Sodium Chloride ( Normal Saline )
• Lactated Ringers
• Dextrose 5% in Water (D5W)



0.9% Sodium Chloride Normal Saline
Uses Special considerations
• Shock
• Resuscitation
• Fluid challenges
• Blood transfusions
• Metabolic alkalosis
• Hyponatremia
• DKA
• Use with caution in patients with heart failure,
edema, or hypernatremia

• Can lead to overload



Lactated Ringers
Uses Special Considerations
• Dehydration
• Burns
• GI tract fluid loss
• Acute blood loss
• Hypovolemia

• Contains Potassium, can cause hyperkalemia
in renal patients
• Patients with liver disease cannot metabolize
lactate
• Lactate is converted into bicarb by liver






Dextrose 5% in Water (D5W)
Uses Special Considerations
• Fluid loss and dehydration
• Hypernatremia

• Solution becomes Hypotonic when dextrose is
metabolized
• Do not use for resuscitation
• Use cautiously in renal and cardiac patients

6. 6



• 0.45% Sodium Chloride (1/2 normal saline)


0.45% Sodium Chloride (1/2 normal saline)
Uses Special Considerations
• Gastric fluid loss
• Cellular dehydration from
excessive diuresis
• Hypertonic dehydration
• Slow rehydration

• Do not give to patients at risk for ICP
• Not for rapid rehydration
• Electrolyte disturbances can occur




• 5% Dextrose in 0.9% Sodium Chloride(D5NS)
• 5% Dextrose in Lactated Ringers (D5LR)
• 5% Dextrose in 0.45% Sodium Chloride (D51/2NS)

5% Dextrose in 0.9% Sodium Chloride(D5NS)
Uses Special Considerations
• Heat related disorders
• Fresh water drowning
• Peritonitis

• Should not be given to patients with impaired
cardiac or renal function
• Draw blood before administering to diabetics


5% Dextrose in Lactated Ringers (D5LR)
Uses Special Considerations
• Hypovolemic Shock
• Hemorrhagic Shock
• Certain cases of acidosis

• Do not administer in patients with cardiac or
renal dysfunction
• Monitor for circulatory overload


5% Dextrose in 0.45% Sodium Chloride (D51/2NS)
Uses Special Considerations
• Heat exhaustion
• Diabetic disorders
• TKO solution in patients with
renal or cardiac dysfunction

• Not for rapid fluid replacement

7. 7



• COLLIDES
 Colloids - contain large insoluble particles which are referred to as solutes, such
as gelatine. Blood is a colloid
 Colloids are made up of much larger solutes than are crystalloids
 Used if crystalloids do not improve blood volume
 Colloids pull fluid into the bloodstream, remember they are always Hypertonic
 Watch for increased BP, Dyspnea, and bounding pulse

For Example:
o Blood, or blood products.
o Albumin
o Plasma Protein fraction
o Dextran
o Hetastarch

Plasma Expanders
EXAMPLES

Action

Indications Nursing
Interventions/Concerns
■ Dextran 70
(isotonic)
■ Dextran 40
(isotonic)
■ 10% mannitol
(hypertonic)
■ 20% mannitol
(hypertonic)
■ 5% albumin
■ 25% albumin
■ 6% hetastarch in
0.9% sodium
chloride
■10% hetastarch
in 0.9% sodium
chloride

Increases volume in
the vascular space.

Will draw fluid out of
intracellular space,
leading to increased
extracellular
volume both in
vascular and
interstitial space

Emergency
treatment of shock
due to fluid or blood
loss.

Treatment of
hypotonic
dehydration.

Treatment of
circulatory collapse.

Increase fluid shift
from interstitial
space to vascular
space

• Monitor patients carefully
for circulatory overload.
• Monitor for hypersensitivity
reactions.
• medications should not
be given with or added to
these solutions
• These solutions can be
very irritating to veins, so
observing the IV site for
inflammation is imperative.
• May cause circulatory
overload, so these
solutions should be infused
slowly to prevent this in
vulnerable patients.
• May increase serum
glucose in patients with
glucose intolerance, which
would make more frequent
glucose monitoring an
important nursing
intervention.

8. 8



2. Buffer solutions:
Buffer solutions are used to correct acidosis or alkalosis. Lactated Ringer's solution also has
some buffering effect. A solution more specifically used for buffering purpose is intravenous
sodium bicarbonate.

3. Other medications
Medications may be mixed into the fluids mentioned above. Certain types of medications can
only be given intravenously, such as when there is insufficient uptake by other routes of
administration such as enterally. Examples include intravenous immunoglobulin and propofol.

4. Other
Parenteral nutrition is feeding a person intravenously, bypassing the usual process
of eating and digestion. The person receives nutritional formulas
containing salts, glucose, amino acids, lipids and added vitamins.
Drug injection used for recreational substances usually enters by the intravenous route.