Administration of ¹³¹I-Metaiodobenzylguanidine Using the Peristaltic Infusion Pump Method

Syringe pumps are commonly used to administer therapeutic (131)I-metaiodobenzylguanidine. Here we describe our recent experience with a peristaltic infusion pump system in a pediatric setting. This method can easily accommodate infusions from several vials simultaneously and is adaptable to various types of peristaltic pump.

Simple off-the-shelf components are used to vent the vial: a charcoal filter, a 0.22-μm syringe filter, and a 2.54-cm (1-in) needle. The vial is connected to the primary infusion set using a male/male extension line and a 19-gauge × 8.89-cm (3.5-in) aspirating needle. With aseptic technique, the extension line is attached to the Y connector closest to the primary intravenous line leading from the saline reservoir to the infusion pump. An A-clamp is attached to the primary intravenous line, immediately before the entrance to the pump. Gravity is allowed to clear the air from the extension set and the aspirating needle. After all the air has been purged, the aspirating needle is inserted into the therapy vial using aseptic technique. The pump is programmed with the desired infusion rate and volume to be infused.

Twenty-one consecutive infusions have been performed to date using this method. Most of the infusions involved the use of 1 vial. On 7 occasions, 2 or 3 vials connected in series were used to successfully administer the therapy. Overestimation of the volume in the vials or of the total infusion time required can cause air to be pulled into the lines. To prevent this, the volume in the vials is equalized to 30 mL, facilitating calculation of the infusion time. If the infusion is observed over the last 2 or 3 mL and the pump stops when the air-fluid mark is about halfway up the extension set, air will be kept out of the primary infusion set.

This method for infusing one or more vials of therapeutic radiopharmaceuticals is robust and easy to use. During infusion, the radiopharmaceutical remains in a shielded vial. Multiple vials can be connected in series to infuse the entire dose simultaneously.