Intravenous simply means "within vein" (or "inside the vein"). Therapies administered intravenously are often included in the designation of specialty drugs. Intravenous infusions are commonly referred to as drips because many systems of administration employ a drip chamber, which prevents air from entering the blood stream (air embolism), and allows an estimation of flow rate.
Intravenous therapy may be used to correct electrolyte imbalances, to deliver medications, for blood transfusion or as fluid replacement to correct, for example, dehydration. Intravenous therapy can also be used for chemotherapy.
Compared with other routes of administration, the intravenous route is the fastest way to deliver fluids and medications throughout the body. The bioavailability of the medication is 100% in IV therapy.
Intravenous infusions are fluid solutions administered through a vein. There are numerous different types of solutions available, but they can be broken down into simple categories depending on the function they serve. Some replace lost fluids, and others provide nutrients, replace lost blood, and deliver medications.
One of the most common uses for intravenous infusions is to replenish fluids lost through dehydration. These infusions often contain normal saline solution, a combination of sterile water and sodium chloride. This solution is known as an isotonic crystalloid, or a solution that contains the same amount of electrolytes as plasma in the body. It is used in cases of moderate to severe dehydration, such as that caused by vomiting or diarrhea, when replacing the fluids quickly is vital.
When a patient`s gastrointestinal tract is compromised and nutrients cannot be absorbed - or eating can worsen the condition - intravenous infusions called total parenteral nutrition may be given. These solutions contain a mix of sterile water, electrolytes, sugar, proteins, fats, and other nutrients, depending on the needs of the patient. Diseases and disorders that commonly require total parenteral nutrition include late stages of Crohn`s disease, obstructive bowel disorder, and ulcerative colitis.
Intravenous infusions are also used to deliver medication directly to the blood stream. Certain medications, such as intravenous immunoglobulin, a type of antibody, can only be given through the vein. Other medications, such as certain narcotic pain relievers, are given intravenously because the method allows them to they work faster than when taken orally. Chemotherapy for treatment of cancer is also typically given intravenously.
When performed by a medical professional, intravenous infusions are typically safe. The most common reaction is mild pain and redness at the site of the injection, although different medications may cause different side effects. Any time the skin is punctured, there is a risk of infection. Having a medical professional, typically a nurse, monitor the intravenous infusion and change the injection site when irritation is evident can help prevent complications.