An intravenous piggyback (IVPB) is a method for delivering a small volume of medication intermittently into a patient’s bloodstream through an existing primary intravenous line. This technique involves attaching a secondary container, typically holding 50 to 250 milliliters of solution, to the main line to infuse a drug, such as an antibiotic, over a specific period. The term “piggyback” is used because the smaller medication bag is hung higher than the larger primary fluid bag. This height difference allows gravity to temporarily interrupt the primary infusion and deliver the medication. This information is provided for educational purposes to help the public understand the process.
Essential Preparation and Supplies
Preparation begins with meticulous verification of the medication order against the patient’s identity and medical record. Healthcare professionals must confirm the “five rights” of medication administration: the right patient, right drug, right dose, right route, and right time. This cross-check is a procedural safeguard to prevent medication errors before the drug is prepared or administered.
A crucial safety step is verifying the chemical compatibility of the secondary medication with the primary IV fluid. If the two solutions are incompatible, they can react upon mixing within the tubing, potentially forming a precipitate or crystals that pose a serious health danger to the patient. Compatibility information is typically found in specialized drug references or hospital formularies.
Once compatibility is confirmed, the necessary supplies must be gathered, including the secondary medication bag, the shorter secondary administration tubing, alcohol wipes, and clean gloves. The IV site is inspected for signs of infiltration or inflammation to ensure the existing line is functional. The secondary tubing roller clamp must be in the closed position before spiking the medication bag to prevent any immediate fluid loss.
Connecting the Secondary Infusion
The mechanical process starts by spiking the secondary medication bag with the sterile spike from the secondary tubing. A preferred technique to ensure a complete air-free line without wasting medication is called “back-priming.” In this method, the secondary tubing is connected to the primary line before it is primed with the drug.
The correct connection point is the Y-port on the primary tubing that is located closest to the primary drip chamber, which is above the infusion pump if one is in use. This specific port is equipped with a backcheck valve that prevents the primary fluid from flowing backward into the main bag. The chosen injection port must be vigorously disinfected with an alcohol wipe for at least five seconds and allowed to dry completely before any connection is made.
The secondary tubing is then connected to the disinfected Y-port. To back-prime, the secondary medication bag is temporarily lowered below the level of the primary IV bag. Opening the secondary tubing clamp allows the primary fluid to flow backward, rising up the secondary tubing and filling the drip chamber about one-third to one-half full, which successfully removes air from the line. Once primed, the clamp is closed, and the secondary bag is raised back up to the higher position on the IV pole.
Initiating and Monitoring the Flow
To begin the infusion, the secondary bag must be physically positioned higher than the primary bag, typically by using a plastic hanger provided with the secondary set to lower the primary bag. This difference in height uses gravity to create a hydrostatic pressure gradient that forces the secondary medication to infuse first, temporarily overcoming the flow of the primary fluid.
If an electronic infusion pump is being used, which is the standard of practice for precise delivery, it must be programmed for the secondary infusion. The pump is set with the total volume of the medication bag and the prescribed infusion rate, usually in milliliters per hour. Modern pumps are designed to automatically stop the primary infusion when the secondary is running and then resume the primary infusion once the secondary volume has been delivered.
After the infusion is initiated, the healthcare professional must remain with the patient for the first few minutes, commonly five minutes, to observe for immediate adverse reactions. This initial monitoring period is critical for detecting signs of an allergic reaction or complications like infiltration, where the fluid leaks out of the vein into surrounding tissue. The IV site and the patient’s overall condition are continuously assessed throughout the entire infusion time.
Discontinuing the Piggyback
Once the secondary medication has been completely infused, the flow of the primary fluid should automatically resume if an infusion pump was used. If the infusion was run by gravity, the primary bag must be manually repositioned to its original height, and the primary roller clamp must be readjusted to resume the correct drip rate. It is important to confirm that the primary fluid is dripping steadily back into the chamber.
The secondary line is then clamped securely at the roller clamp to prevent any backflow or leakage. The secondary tubing can be disconnected from the Y-port of the primary line, and the empty medication bag and tubing are typically discarded according to the facility’s protocol for biohazardous waste. If the patient is scheduled to receive the same secondary medication again soon, the tubing may be left connected to the primary line to reduce the risk of infection from repeated connections, following institutional guidelines. The final step involves documentation of the infusion, including the time, volume infused, and the patient’s response to the medication.