The purpose of a saline lock (intermittent IV device) is to:

Rationale: A. Maintain IV access without continuous infusion is correct. A saline lock, also called an intermittent IV device, allows a peripheral IV catheter to remain patent without requiring a continuous fluid infusion. The line is flushed with saline periodically to keep it open, making it convenient for patients who need intermittent medications or fluids without being attached to an IV bag continuously. B. Increase medication absorption is incorrect because a saline lock does not affect how medications are absorbed. IV medications are delivered directly into the bloodstream, and absorption is immediate regardless of a saline lock. C. Provide continuous IV fluids is incorrect because a saline lock is specifically not used for continuous fluid administration. If continuous fluids are needed, a standard IV setup with an infusion pump or gravity system is used instead. D. Prevent phlebitis is incorrect because while proper IV care can reduce phlebitis, the primary purpose of a saline lock is access, not preventing vein inflammation. Phlebitis prevention depends on site selection, catheter size, and monitoring, not the presence of a saline lock itself.