Testing the safety of Baxter continuous cardiac output monitoring system.

The safety of a new continuous cardiac output monitoring system, recently introduced by Baxter Healthcare Corporation's Edwards Critical-Care Division, was evaluated in normal sheep. The study compared the biocompatibility and safety of the Vigilance CCO Monitoring System, which employs a continuous cardiac output (CCO) catheter with Baxter Edward's standard Paceport pulmonary artery catheter. The CCO catheter, which monitors hemodynamic pressures and provides continuous measurement of cardiac output based on the thermodilution principle, contains a thermal filament that is powered and controlled by a unique cardiac output monitor. Parameters were measured periodically in conscious animals and complete necropsies were performed after each study. Time Control, Paceport, and four CCO groups were studied. Selected groups were studied for 3 days (acute), 7 days (subacute), and/or 4 weeks after 3 days of continuous use (recovery). Results showed no significant differences between the CCO and Paceport catheters in any of the parameters studied. On gross pathology, observations were similar. The only difference between catheters were microscopic findings of focal subendothelial or subendocardial changes correlated with areas that could have come into contact with the CCO catheter. In acute groups, these changes consisted of a localized myofiber degeneration or necrosis, while in subacute and recovery groups, consisted only of fibrosis. None of the changes were clinically significant. Thus, the CCO catheter, used in conjunction with the Vigilance CCO Monitoring System, appears to pose no additional risk over a standard Paceport catheter in normal sheep after continuous use for up to 7 days.