Device to limit inflation of a pulmonary artery catheter balloon

OBJECTIVE: The most serious complication seen with pulmonary artery catheters is rupture of the pulmonary artery. The effectiveness of an external safety balloon added to the pulmonary artery balloon inflation port was tested. DESIGN: The external balloon is designed to inflate and absorb excess volume from the inflation syringe after the internal balloon contacts the vessel wall. When the catheter tip is in a small pulmonary artery, expansion of the external balloon indicates that the catheter tip is in a noncompliant or small vessel. SETTING: The external balloon was tested in a bench simulation. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The pulmonary artery balloon was slowly inflated inside 2.6-, 3.0-, 4.7-, 8.6-, and 11.6-mm internal diameter polyvinyl chloride tubes, with and without the external safety device in place. Without the external balloon, the average balloon pressure was 1647 +/- 145 (SD) mm Hg in the 2.6-mm vessel. With the external balloon in use, the maximum pulmonary artery balloon pressure was 473 +/- 7.2 mm Hg in the 2.6-mm vessel. CONCLUSIONS: The external balloon can limit balloon pressures within the pulmonary artery and identify when excessive volumes are being forced into the pulmonary artery balloon.