Injection of air bubbles during flushing of angiocatheters: an in vitro trial of conventional hardware and techniques.

BACKGROUND AND PURPOSE Injected air bubbles are a well-accepted cause of stroke during cerebral angiography. We used an in vitro model to determine the frequency of occurrence of air emboli during catheter flushing using conventional hardware and techniques. METHODS Two experimental models were used in this study. The first incorporated an in-line bubble trap. Ten members of our angiography section flushed this system in their usual fashion and then with two modifications of the hardware. The trap was inspected after each trial of seven injections and any visible bubble was measured with calipers. The second model used a peristaltic pump along with a transcranial Doppler device to look at the relative number of bubble events with modifications of the flush solution or technique. RESULTS The closed-flush set in common usage in our department caused an increase in the number of visible bubbles in the trap as compared with an open basin. Degassing the solution and delaying injection decreased the number of bubble events noted in model 2. CONCLUSION Bubble emboli are commonplace during flushing of angiography catheters when using conventional techniques and equipment.