Parenteral nutrition is a method of delivering nutrients directly into the bloodstream, which completely bypasses the digestive system. This requires placing a thin intravenous tube called into a large vein in the chest. These tubes are called percutaneous intravenous catheter lines.

For feeding, a bag containing special liquid nutrients and medication is attached to the catheter. The fluid enters the bloodstream through the vein. Parenteral nutrition is used only for severe gastroparesis and malnutrition.