I have never seen any literature that states you need a specific order to access a port other than the order for the IV solution and rate. In the State of Maryland (and many others I am sure) nurses specially trained can actually place and remove the device. This does require a specific order but not just to access the device.
By sq port, I am assuming that you mean an implanted venous port and not a device for subcutaneous infusion. For any implanted port use, the decision about requirements for a physician's order depends upon your hospitals policy and procedure. See Infusion Nursing Standard of Practice #45 Implanted Ports and Pumps, page S45-46.
Lynn Hadaway, M.Ed., RN, BC, CRNI
Lynn Hadaway Associates, Inc.
126 Main Street, PO Box 10
Milner, GA 30257
Office Phone 770-358-7861