Guidelines for Flushing IV Lines Between Medications

The topic of how long to flush IV lines between noncompatible chemotherapeutic medications was brought up at a team meeting at our outpatient infusion center. Are there any published studies regarding the required amount to use to flush a line before the next medication can be hung? — Name withheld on request

Guidelines related to the required amount of normal saline solution (NSS) to flush a line between medications vary and appear to be institution-based. The only consistency in the literature is that all lines should utilize a 10-mL syringe to preserve the patency and functionality of the catheter in adult patients and 3 mL for pediatric patients.

The California Department of Health Care Services recommends flushing the IV line between medications based on the type of line (ie, PICC vs Groshong). These guidelines suggest flushing the line with as little as 3-10 mL NSS after antibiotics and with as much as 20 mL after total parenteral nutrition (TPN). Use of heparin is per institution guidelines and physician order. Review of the Institute for Safe Medication Practices provides very little standards for the amount for flushing, but does endorse the use of a 10-mL syringe.