Over-the-Wire Catheter Exchanges: Reduction of the Risk of Air Emboli

Purpose: This study evaluated the aerostatic properties of the catheter clamp during over-the-wire catheter exchanges and determined if protective devices reduce volumes of air emboli (AE). Materials and Methods: A cuffed catheter was placed in an AE model in physiologic conditions and the volume of AE was recorded during 60 seconds (n = 10). Similarly, the volume of AE entering the model during 30 seconds was recorded with the catheter clamp open (n = 10) or closed over the wire (n = 10), and with the sliding clamp in the open position (n = 10). The volume of AE during 60 seconds was recorded with the sliding clamp closed over the wire (n = 10) and with the aerostatic valve with (n = 10) and without (n = 10) a wire in place. Results: Without a wire, no AE occurred with the catheter clamp closed (60 seconds, n = 10). There was no statistically significant difference between the volumes of AE with the catheter clamp open or closed over the wire during 30 seconds (43 mL ± 4 and 32 mL ± 11, respectively). With the protective devices in place and the wire unchanged in position, no AE occurred during 60 seconds. A positive control (sliding clamp and catheter clamp open, n = 10) yielded AE volumes of 44 mL ± 5 in 30 seconds. Conclusions: AE can occur with the catheter clamp closed over a wire. Protective devices reduce the volume of AE under simulated physiologic conditions and are recommended with over-the-wire catheter exchanges.