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.
Replacing blood and blood products lost through surgery and trauma is another common use of infusions. Patients with certain disorders that hinder the body’s ability to make new blood may also require blood transfusions. Depending on the needs of the patient, the transfusion may contain whole blood or just certain parts, such as plasma or platelets. The blood in the transfusion bag must match the blood type of the patient, with the exception of type AB, the universal recipient. Type O blood can be given to any blood type.
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.