What is Intravenous Fluid Therapy?

Intravenous fluid therapy is a commonly used procedure in hospitals and medical facilities that delivers fluids through sterile tubing into a needle inserted into a vein. A large percentage of patients in a hospital will undergo this therapy, often just called an IV. This procedure can be used to provide hydration, nutrition, to transfuse blood, or to administer medications.

The primary reason IV therapy is so widely used is forces fluids to enter the body quicker than any other route. An intravenous fluid therapy delivery system is convenient for medical professionals because it is easy to administer and to change fluids as needed. Since the apparatus can be hung from a pole on wheels, the patient can maintain mobility and walk while attached to the IV.

A basic intravenous fluid therapy system consists of a collapsible bag or bottle of solution, a drip chamber that controls flow rate, connectors, and a needle held in place by dressing. The needle is usually inserted into a vein, often in the hand or arm. Veins are used because they are close to the surface of the skin, easy to see, and unlike arteries, do not pulse.

Flow rate can be controlled by an infusion pump that has a timer and controls amount administered. A gravity drip may be used by hanging the bag higher than the patient. Syringe pumps administer small amounts of concentrated medications. They may be used when fluids need to be administered less frequently and when patients cannot tolerate constant infusion with fluids.

There are two types of fluids used in intravenous fluid therapy: crystalloid and colloid. Crystalloid solutions are sterile water mixed with electrolytes. The two most commonly used crystalloid solutions used in the United States are normal saline and lactated Ringers. Colloids are crystalloid fluids that have an additional substance made up of larger particles that are too large to pass through the vein wall. Although rarely used due to expense, they are sometimes needed to reduce edema and control blood volume.

As with most medical procedures, there is a risk of infection with intravenous fluid therapy. The most common complication is phlebitis, a condition in which the vein wall becomes inflamed, causing pain and swelling, usually of the leg. Sometimes a blood clot may form near the site of inflammation. Phlebitis is treated with heat, elevation, and anti-inflammatory drugs, like aspirin or ibuprofen, and removing the IV and reinserting at another site.