What is the purpose of hanging the secondary piggyback IV medication higher than the primary IV solution?

An intravenous (IV) piggyback is a way to administer medication through an intravenous tube that is inserted into a patient's vein. This can be an antibiotic or another type of medication that needs to be diluted and administered slowly. The medication in an IV piggyback is mixed in a small amount of compatible fluid, such as normal saline or dextrose with saline.

Gravity Drip

The IV piggyback is aptly named because the medication is given on top of the main intravenous solution. This allows for the intermittent infusion of medications at specific times. The piggyback infusion usually is hung higher than the main IV solution and is connected to a port in the main tubing. Hanging the IV piggyback higher than the main solution causes it to infuse faster than the main solution.

IV Pump

If an IV pump is used rather than allowing gravity to cause the IV fluid to drip, then the nurse can electronically program the pump. The pump can control the flow of each medication or solution and can even stop the main IV infusion and allow the secondary medication to infuse. After the IV piggyback is finished, the main fluids will begin to infuse once again. When an IV pump is used, the height at which each of the bags is hung does not matter.

Saline Lock

A piggyback infusion also can be administered without a main IV fluid infusing. A patient can have IV access called a saline lock, or heparin lock. A saline lock is an intravenous catheter that is inserted into a vein and then capped, which allows periodic access to the vein for medication administration. An IV piggyback can be attached to the saline lock every few hours and then disconnected after the medication has infused.

Medication Compatibility

The medications in the piggyback infusion might not be compatible with other IV piggybacks. If two incompatible medications mix in the same line, it could form a precipitate or crystallize in the tubing. Therefore, it is important that the intravenous tubing be flushed between IV piggyback administrations. This flush can be performed by lowering the secondary tubing to allow the main intravenous solution to back up into the secondary line to flush it.

Some hospital policies require a separate IV piggyback line for each medication. When there is a dedicated line for each medicine, there is little risk for incompatible medications mixing. This can become a challenge if a patient is on several intravenous piggybacks, because of the number of IV lines that will be hanging from the pole.

Saline Flush

If the patient does not have a main intravenous fluid infusing, the saline lock should be flushed with normal saline before and after the administration of an intravenous piggyback. This will clear any remaining medication left behind in the saline lock.

Why Might Someone Need an IV Piggyback? 

There are countless reasons why a patient’s condition might necessitate an IV piggyback. Any situation where two medications need to get delivered in a controlled fashion can be a reason to implement this method. 

One common scenario is when a patient has an infection and needs pain medication and antibiotics delivered on a controlled basis. These medications usually have different dosing schedules and requirements, and the secondary bag helps medical providers administer doses efficiently. 

Another example is when the patient needs an IV for hydration and medication. The primary bag is usually used for the hydrating solution, while the small piggyback delivers the required drug. 

Medical professionals evaluating the patient decide which medications are needed and the best way for the medications to get administered. 

Who Sets Up an IV Piggyback, and How Is It Done? 

An IV piggyback is always set up by a medical professional, most often a nurse or a doctor. Some hospitals have IV teams that are trained and experienced in getting intravenous medications delivered quickly and painlessly to all patients. 

The doctor will order medications for the patient, and those medications will be filled at the hospital pharmacy. The people administering the IV and IV piggyback will double-check to ensure the drugs are the correct ones for the patient. They will then check that there aren’t contraindications that could harm the patient. 

The people administering the IV piggyback then attach the secondary (piggyback) line to the main infusion line. They do this by hanging the piggyback bag higher than the main infusion bag. They can program the IV pump to deliver the medications at the appropriate times and in the right amounts. 

Risks Associated With IV Piggyback 

Medical professionals get extensive training on how to properly set up an IV as well as an IV piggyback. In most cases, all goes well. As with any medical procedure or process, there are risks associated with using an IV piggyback. 

These risks are often due to mechanical issues or user errors of the equipment involved in the procedure. These errors can include: 

Concurrent Flow

As mentioned previously, any medications that need to get administered at separate times must remain on those separate schedules. If certain medications mix or are given too quickly, this can cause health risks for the patient. 

Concurrent flow can happen when the primary IV bag and the piggyback bags are hung incorrectly. This error causes the medication to be infused at the wrong times or at an uncontrolled rate of speed. It can also cause the backcheck valve to malfunction, allowing unwanted medication delivery speeds. 

Connection Mistakes

Errors in connection are another scenario that falls under this category. If the primary infusion bag is connected to the secondary bag through the wrong port, medications can mix and get administered at the incorrect times. 

Secondary Valve Error

The valves must function correctly, so the medication reaches the patient at the right time and in the correct dosage. 

In a secondary valve error, the medicine in the secondary bag (the IV piggyback) cannot reach the patient at all, and the contents of the primary bag are delivered at a slower rate. Understandably, this can cause serious complications. 

How Long Does an IV Piggyback Stay On? 

IV piggybacks get placed so that a patient can receive a specific medication in a relatively short yet controlled time frame. The IV piggyback remains attached until the medication inside it runs out or is no longer needed. 

If more medication or a different medication is needed, it can be switched out, and a new piggyback bag gets added. Because the IV piggyback is a secondary bag, it’s easy to remove and replace. The primary infusion bag is not affected by any of these changes. 

Final Thoughts About IV Piggybacks

Being in the hospital and needing an IV is stressful for anyone. If you need an IV or IV piggyback and have questions about your treatments, don’t hesitate to speak with your medical team. 

It’s always best to communicate with your doctors about any issues with your medications or the methods used to administer them.