The most common type of isotonic fluids are 0.9% sodium chloride solutions.
There are several different types of intravenous (IV) fluids given to patients, the most common being isotonic fluids. These fluids have the same number of dissolved particles as a person’s blood. Using this type of fluid prevents extra particles from entering or leaving the patient’s cells. Isotonic fluids are commonly given intravenously in order to rehydrate a patient or maintain their hydration level.
An IV may be given into the back of the hand if the veins in the arm are inaccessible.
The most common type of isotonic fluids are 0.9% sodium chloride solutions, also called normal saline fluids. The salt content of the fluids matches the normal levels in a person’s bloodstream and maintains a fluid and salt balance between the bloodstream and the cells while the patient is being hydrated. Normal saline fluids are used to treat patients who are receiving blood transfusions, in shock, or suffering from diabetic ketoacidosis. They can be harmful to patients suffering from heart failure.
Normal saline fluids are given in conjunction with blood transfusions.
Another type of isotonic fluid commonly given to patients is a 5% dextrose solution. This type of isotonic fluid, often called D5W, is used in patients suffering from dehydration or high blood salt levels. Patients with heart or kidney failure may have complications with the use of these fluids.
Lactate Ringer’s fluid, or LR fluid, is another type of isotonic solution and contains lactate of calcium, potassium, and sodium chloride in slightly different concentrations depending on the manufacturer. In this type of isotonic solution, however, the concentration of each of these components is low. LR fluid is used to rehydrate patients or to help those with blood or fluid loss due to illness or injury to the intestines. Patients with liver or kidney problems cannot tolerate LR fluids and require an alternative treatment.
Isotonic IV fluids are often given to a patient to hydrate them.
In addition to isotonic fluids, there are also hypotonic and hypertonic fluids. Hypotonic fluids contain fewer dissolved particles than blood, and their administration causes particles within cells to flow from the cell into the blood. Hypertonic fluids, on the other hand, contain more dissolved particles than blood and cause the cells to absorb the particles to equalize the concentration between the cells and the bloodstream.