ARRT Practice Exam for Radiologic Technologists – United States Prep & Study Guide

Keeping an IV bag 18 to 20 inches above the level of the vein is primarily to prevent the backflow of blood and clot formation. When the IV bag is positioned higher than the vein, the force of gravity facilitates the flow of the intravenous fluid into the patient’s bloodstream, minimizing the chance of backflow. Backflow can lead to the stagnation of blood in the catheter, increasing the risk of clot formation, which can obstruct the IV line and impede proper fluid administration.

The height of the IV bag creates hydrostatic pressure that ensures a continuous flow of fluid into the vein, maintaining the patency of the IV line while also providing a more efficient and effective delivery of medications and fluids to the patient. Proper placement of the IV bag is an important consideration in intravenous therapy and is influenced by factors such as fluid viscosity and flow rate requirements.