Secondary I.V. Lines

A secondary I.V. line is a complete I.V. set—container, tubing, and microdrip or macrodrip system—connected to the lower Y-port (secondary port) of a primary line instead of to the I.V. catheter or needle. It can be used for continuous or intermittent drug infusion. When used continuously, a secondary I.V. line permits drug infusion and titration while the primary line maintains a constant total infusion rate.

When used intermittently, a secondary I.V. line is commonly called a piggyback set. In this case, the primary line maintains venous access between drug doses. Typically, a piggyback set includes a small I.V. container, short tubing, and a macrodrip system. This set connects to the primary line's upper Y-port, also called a piggyback port. Antibiotics are most commonly administered by intermittent (piggyback) infusion. To make this set work, the primary I.V. container must be positioned below the piggyback container. (The manufacturer provides an extension hook for this purpose.)

Most drugs can be piggybacked with a needle-free system, which consists of a blunt-tipped plastic insertion device and a rubber injection port. The port may be part of a special administration set or an adapter for existing administration sets. The rubber injection port has a preestablished slit that can open and reseal immediately. The needle-free system aims to reduce the risk of accidental needle-stick injuries.

I.V. pumps may be used to maintain constant infusion rates, especially with a drug such as lidocaine. A pump allows more accurate titration of drug dosage and helps maintain venous access because the drug is delivered under sufficient pressure to prevent clot formation in the I.V. cannula.


Patient's medication record and chart • prescribed I.V. medication • prescribed I.V. solution • administration set with secondary injection port • needleless adapter • alcohol pads • 1″ adhesive tape • time tape • labels • infusion pump • extension hook and appropriate solution for intermittent piggyback infusion • optional: normal saline solution for infusion with incompatible solutions.

For intermittent infusion, the primary line typically has a piggyback port with a backcheck valve that stops the flow from the primary line during drug infusion and returns to the primary flow after infusion. A volume-control set can also be used with an intermittent infusion line.

Preparation of equipment

Verify the order on the patient's medication record by checking it against the physician's order. Wash your hands. Inspect the I.V. container for cracks, leaks, and contamination, and check drug compatibility with the primary solution. Verify the expiration date. Check to see whether the primary line has a secondary injection port. If it doesn't and the medication is to be given regularly, replace the I.V. set with one that has a secondary injection port.

If necessary, add the drug to the secondary I.V. solution. To do so, remove any seals from the secondary container, and wipe the main port with an alcohol pad. Inject the prescribed medication, and gently agitate the solution to mix the medication thoroughly. Properly label the I.V. mixture. Insert the administration set spike and attach the needle. Open the flow clamp and prime the line. Then close the flow clamp.

Some medications are available in vials that are suitable for hanging directly on an I.V. pole. Instead of preparing medication and injecting it into a container, you can inject diluent directly into the medication vial. Then you can spike the vial, prime the tubing, and hang the set, as directed.


Confirm the patient's identity by asking his name and checking the name, room number, and bed number on his wristband.

If your facility utilizes a bar code scanning system, be sure to scan your ID badge, the patient's ID bracelet, and the medication's bar code.

If the drug is incompatible with the primary I.V. solution, replace the primary solution with a fluid that's compatible with both solutions, such as normal saline solution, and flush the line before starting the drug infusion. Many facility protocols require that the primary I.V. solution be removed and that a sterile I.V. plug be inserted into the container until it's ready to be rehung. This maintains the sterility of the solution and prevents someone else from inadvertently restarting the incompatible solution before the line is flushed with normal saline solution.

Hang the secondary set's container, and wipe the injection port of the primary line with an alcohol pad.

Insert the needleless adapter from the secondary line into the injection port, and secure it to the primary line.

To run the secondary set's container by itself, lower the primary set's container with an extension hook. To run both containers simultaneously, place them at the same height. (See Assembling a piggyback set, page 250.)

Open the clamp and adjust the drip rate. For continuous infusion, set the secondary solution to the desired drip rate; then adjust the primary solution to achieve the desired total infusion rate.

For intermittent infusion, adjust the primary drip rate, as required, on completion of the secondary solution. If the secondary solution tubing is being reused, close the clamp on the tubing and follow your facility's policy: Either remove the needleless adapter and replace it with a new one, or leave it securely taped in the injection port and label it with the time it was first used. In this case, also leave the empty container in place until you replace it with a new dose of medication at the prescribed time. If the tubing won't be reused, discard it appropriately with the I.V. container.

Special considerations

If policy allows, use a pump for drug infusion. Put a time tape on the secondary container to help prevent an inaccurate administration rate.

When reusing secondary tubing, change it according to your facility's policy, usually every 48 to 72 hours. Similarly, inspect the injection port for leakage with each use, and change it more often if needed.

Unless you're piggybacking lipids, don't piggyback a secondary I.V. line to a total parenteral nutrition line because of the risk of contamination. Check your facility's policy for possible exceptions.


The patient may experience an adverse reaction to the infused drug. In addition, repeated punctures of the secondary injection port can damage the seal, possibly allowing leakage or contamination.


Record the amount and type of drug and the amount of I.V. solution on the intake and output and medication records. Note the date, duration and rate of infusion, and patient's response, where applicable.