Final answer:
A patient is placed in slight Trendelenburg position for non-tunneled catheter placement to prevent air from entering the venous system and causing an air embolism.
Step-by-step explanation:
When a patient undergoes non-tunneled catheter placement, they are often placed in a slight Trendelenburg position. This position involves elevating the patient's head slightly and lowering the foot of the bed. The purpose of this position is to help prevent air from entering the venous system and potentially causing an air embolism. Placing the patient in a slight Trendelenburg position helps to maintain venous pressure and prevent air from being drawn into the catheter during the procedure.