Epidural Multiorifice Catheters Function as Single-Orifice Catheters: An In Vitro Study

Abstract

In an in vitro study, we determined the flow rates required to use selective orifices of multiorifice catheters. Saline was infused at rates between 1 and 360 mL/h through Portex and Braun 20-gauge multiorifice catheters using Baxter, Abbott Laboratories, and Alaris infusion pumps. The numbers of orifices used via infusion and manual injection, and the pressure within the catheter during continuous infusion, were recorded. Infusion rates <80 mL/h used one orifice, between 100 and 280 mL/h used two orifices, and >300 mL/h used three orifices. Catheter pressures with Braun catheters were 40% greater than with Portex catheters. Manual injections by all 12 residents used all three orifices. Twenty-gauge multiorifice catheters function as single-orifice catheters at clinically relevant infusion rates, but function as multiorifice catheters during manual boluses.