Final answer:
When changing central line tubing, the patient should lie flat to ensure their comfort and stability, minimize the risk of complications, and prevent air bubbles from entering the bloodstream.
Step-by-step explanation:
When changing central line tubing, the patient should be told to lie flat. This position helps ensure the patient's comfort and stability during the procedure, as well as minimize the risk of air embolism or other complications.
Lying flat allows gravity to prevent air bubbles from entering the bloodstream through the catheter. It also helps maintain the integrity of the tubing and reduces the chances of accidental dislodgement.