Final answer:
When an arterial needle has infiltrated, a new needle should be placed at a different site, preferably upstream from the initial site or on a different extremity after addressing any infiltration complications.
Step-by-step explanation:
If an arterial needle has infiltrated, it is important to first address any complications that have arisen from the infiltration, such as swelling or bleeding. Once these have been managed, if reinsertion of a needle is required, it should be done at a different site, preferably upstream from the previous site or on another extremity.
This is done to prevent further damage to the initially infiltrated area and to maintain the integrity of the vasculature. It is important for the clinician to assess the patient's vascular access options, taking into consideration the presence of any infections, patient comfort, and the availability of alternate access sites.