An intravenous portal, usually placed and left in a vein in one of the patient’s arms, that is used episodically for fluid or medication infusions. Salt water flushes are used to maintain its patency. Saline locks replaced heparin locks in the 1990s because of cost and efficacy, and the latter posed a rare but unacceptable risk of heparin-related allergies (especially heparin-related thrombocytopenia).