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, is a short catheter inserted into a peripheral vein and capped with a heparin or saline flush port. Its purpose is to keep the vein patent (open) for intermittent IV medication administration or emergency access, without requiring the patient to be attached to a continuous IV fluid line. Between uses, the line is flushed with saline to prevent clot formation and maintain patency. This is especially useful for patients who do not require continuous fluid replacement but may need rapid IV access for medications, fluids, or emergency interventions. B. Provide continuous IV fluids is incorrect because a saline lock is specifically designed for intermittent use. Continuous IV therapy requires a standard IV line with a fluid bag and infusion pump, which delivers fluids at a constant rate. Using a saline lock in place of a continuous infusion would not maintain adequate fluid administration. C. Increase medication absorption is incorrect because the saline lock does not affect how the medication is absorbed. It is simply a method for delivering IV medications directly into the bloodstream. Absorption occurs the same way whether administered through a saline lock or continuous IV. D. Prevent phlebitis is incorrect because while proper flushing of a saline lock can reduce the risk of clot formation or catheter occlusion, it does not prevent phlebitis, which is inflammation of the vein due to mechanical irritation, chemical irritation from medications, or infection. Preventing phlebitis involves correct catheter insertion technique, appropriate catheter size, careful medication selection, and monitoring the insertion site.