Final answer:
In the event of a disconnected IV from a PICC with symptoms of tachycardia, chest pain, and shortness of breath, the nurse should place the client in the left side-lying Trendelenburg position to prevent complications such as an air embolism.
Step-by-step explanation:
When a client experiences tachycardia, chest pain, and shortness of breath due to a disconnected IV infusion tubing from a peripherally inserted central catheter (PICC), it is critical to act swiftly to prevent further complications such as an air embolism. The nurse should place the client in the left side-lying Trendelenburg position. This positioning helps prevent air from traveling to the lungs by trapping it in the right atrium or ventricle, as it is less likely to enter the pulmonary circulation when the patient is lying on the left side.
Additionally, the Trendelenburg position, where the client's feet are elevated higher than the head, can further help by using gravity to prevent the air from moving towards the heart and lungs.