Get to know the different types of intravenous solutions or IV fluids in this guide and cheat
sheet. Differentiate isotonic, hypertonic, and hypotonic IV solutions and the nursing
interventions and management for each.
What are IV Fluids?
Intravenous fluids (IV Fluids), also known as intravenous solutions, are
supplemental fluids used in intravenous therapy to restore or maintain normal fluid volume
and electrolyte balance when the oral route is not possible. IV fluid therapy is an efficient
and effective way of supplying fluids directly into the intravascular fluid compartment, in
replacing electrolyte losses, and in administering medications and blood products.
Types of IV Fluids
There are different types of IV fluids and different ways on how to classify them.
The most common way to categorize IV fluids is based on their tonicity:
• Isotonic. Isotonic IV solutions that have the same concentration of solutes as
blood plasma.
• Hypotonic. Hypotonic solutions have lesser concentration of solutes than plasma.
• Hypertonic. Hypertonic solutions have greater concentration of solutes than plasma.
IV solutions can also be classified based on their purpose:
• Nutrient solutions. May contain dextrose, glucose, and levulose to make up the
carbohydrate component – and water. Water is supplied for fluid requirements and
, carbohydrate for calories and energy. Nutrient solutions are useful in
preventing dehydration and ketosis. Examples of nutrient solutions include D5W,
D5NSS.
• Electrolyte solutions. Contains varying amounts of cations and anions that are used
to replace fluid and electrolytes for clients with continuing losses. Examples of
electrolyte solutions include 0.9 NaCl, Ringer’s Solution, and LRS.
• Alkalinizing solutions. Are administered to treat metabolic acidosis. Examples: LRS.
• Acidifying solutions. Are used to counteract metabolic alkalosis. D51/2NS, 0.9 NaCl.
• Volume expanders. Are solutions used to increase the blood volume after a
severe blood loss, or loss of plasma. Examples of volume expanders are dextran,
human albumin, and plasma.
Crystalloids
Crystalloid IV solutions contain small molecules that flow easily across semipermeable
membranes. They are categorized according to their relative tonicity in relation to plasma.
There are three types: isotonic, hypotonic, and hypertonic.
Isotonic IV Fluids
Most IV fluids are isotonic, meaning, they have the same concentration of solutes as blood
plasma. When infused, isotonic solutions expand both the intracellular
fluid and extracellular fluid spaces, equally. Such fluids do not alter the osmolality of the
vascular compartment. Technically, electrolyte solutions are considered isotonic if the total
electrolyte content is approximately 310 mEq/L. Isotonic IV fluids have a total osmolality
close to that of the ECF and do not cause red blood cells to shrink or swell.
sheet. Differentiate isotonic, hypertonic, and hypotonic IV solutions and the nursing
interventions and management for each.
What are IV Fluids?
Intravenous fluids (IV Fluids), also known as intravenous solutions, are
supplemental fluids used in intravenous therapy to restore or maintain normal fluid volume
and electrolyte balance when the oral route is not possible. IV fluid therapy is an efficient
and effective way of supplying fluids directly into the intravascular fluid compartment, in
replacing electrolyte losses, and in administering medications and blood products.
Types of IV Fluids
There are different types of IV fluids and different ways on how to classify them.
The most common way to categorize IV fluids is based on their tonicity:
• Isotonic. Isotonic IV solutions that have the same concentration of solutes as
blood plasma.
• Hypotonic. Hypotonic solutions have lesser concentration of solutes than plasma.
• Hypertonic. Hypertonic solutions have greater concentration of solutes than plasma.
IV solutions can also be classified based on their purpose:
• Nutrient solutions. May contain dextrose, glucose, and levulose to make up the
carbohydrate component – and water. Water is supplied for fluid requirements and
, carbohydrate for calories and energy. Nutrient solutions are useful in
preventing dehydration and ketosis. Examples of nutrient solutions include D5W,
D5NSS.
• Electrolyte solutions. Contains varying amounts of cations and anions that are used
to replace fluid and electrolytes for clients with continuing losses. Examples of
electrolyte solutions include 0.9 NaCl, Ringer’s Solution, and LRS.
• Alkalinizing solutions. Are administered to treat metabolic acidosis. Examples: LRS.
• Acidifying solutions. Are used to counteract metabolic alkalosis. D51/2NS, 0.9 NaCl.
• Volume expanders. Are solutions used to increase the blood volume after a
severe blood loss, or loss of plasma. Examples of volume expanders are dextran,
human albumin, and plasma.
Crystalloids
Crystalloid IV solutions contain small molecules that flow easily across semipermeable
membranes. They are categorized according to their relative tonicity in relation to plasma.
There are three types: isotonic, hypotonic, and hypertonic.
Isotonic IV Fluids
Most IV fluids are isotonic, meaning, they have the same concentration of solutes as blood
plasma. When infused, isotonic solutions expand both the intracellular
fluid and extracellular fluid spaces, equally. Such fluids do not alter the osmolality of the
vascular compartment. Technically, electrolyte solutions are considered isotonic if the total
electrolyte content is approximately 310 mEq/L. Isotonic IV fluids have a total osmolality
close to that of the ECF and do not cause red blood cells to shrink or swell.
