Total parenteral nutrition (TPN) is a way to supply nutrition to the body via the veins, which prevents the catabolism of the body’s lean muscle and subcutaneous fat in a patient who cannot receive oral nutrition. The risk of TPN is air embolism, not thromboembolism. The TPN formulation contains fats, proteins and carbohydrates, so carbohydrates do not need to be consumed orally. There are standard TPN formulations, but they can be altered. The addition of medications to the TPN formulation is generally not done if it can be avoided but is not always contraindicated. Medications like regular insulin and heparin can be added to the formulation. Insulin is used to control hyperglycemia. Fluid volume status must be closely monitored to prevent fluid overload and subsequent hypertension and edema. TPN increases the risk for infection and must be used sparingly.