In vitro comparison of central venous catheters for aspiration of venous air embolism: effect of catheter type, catheter tip position, and cardiac inclination.

STUDY OBJECTIVE To test the relative efficiency of balloon-tipped and plain catheters for aspiration of venous air embolism. DESIGN The following four single-lumen central venous catheters were studied in a silastic model of the right atrium, tricuspid valve, and vena cavae: (1) the 16-gauge single-orifice catheter; (2) the 14-gauge Bunegin-Albin multiorifice catheter; (3) the 7-Fr pulmonary angiography catheter with balloon distal to orifices; (4) the 7-Fr pulmonary angiography catheter with balloon proximal to orifices. A 10% glycerol-water solution was circulated at 3.7 to 4.0 L/min. Catheter tips were positioned at 1 cm increments from -3 to +3 cm around the superior vena cava-right atrial junction with cardiac inclinations of 65 degrees and 80 degrees. Air (10 ml) was infused over 30 seconds; aspiration from the test catheter began 5 seconds later at 40 ml/min for 75 seconds. The balloon catheters were evaluated with the balloons inflated and deflated. SETTING Experimental laboratory of a university-affiliated hospital. MEASUREMENTS AND MAIN RESULTS Amounts of air aspirated were compared by analysis of variance and Tukey's multiple comparison, p less than 0.05, for all combinations. The 16-gauge single-orifice catheter tested best at a 65 degrees cardiac inclination with 86% of the venous air embolism recovered, while the 14-gauge Bunegin-Albin multiorifice catheter tested best at an 80 degrees cardiac inclination with 62% of the venous air embolism recovered. Both catheters functioned most efficiently at or above the superior vena cava-right atrial junction. CONCLUSIONS This study demonstrated that efficacy of air recovery depends on catheter type, catheter tip position, and cardiac inclination. No benefit was derived from positioning the catheter tip inside the atrium or from using balloon-tipped catheters.