Simultaneous Pulmonary Artery Catheter and Pulse Contour Measurements in a Patient With an LVAD

Abstract

Although pulmonary artery catheters are highly effective for hemodynamic profiling, they are indwelling invasive devices with inherent risks and are recommended only in a select group of critically ill patients. The Flotrac sensor is a new device that measures continuous cardiac output (CO) via a peripheral arterial line. This article reports the first case of simultaneous measurement of CO from pulse contour analysis using a continuous CO monitor (Flotrac), the thermodilution method from a pulmonary artery catheter, and a surgically implanted left ventricular assist device (LVAD; HeartMate XVE). Six data points were obtained from each modality over 15 hours. Mean COs for the LVAD, pulmonary artery catheter, and sensor were 6.9 ± 0.4 L/min (range, 6.2-7.5 L/min), 7.8 ± 1.1 L/min (range, 5.9-8.8 L/min), and 7.2 ± 0.7 L/min (range, 6.3-8.2 L/min), respectively. There was some agreement between the 3 devices used to measure CO as assessed by Bland-Altman analysis, but the small sample size limited statistical significance. The sensor system is an intriguing semi-invasive method to monitor CO via arterial flow in a patient with LVAD, but more rigorous diagnostic studies are needed to evaluate the validity of pulse contour devices prior to widespread use in this critically ill population.