Continuous arterial pressure waveform monitoring in pediatric cardiac transplant, cardiomyopathy and pulmonary hypertension patients.

Purpose: A continuous cardiac output monitor based on arterial pressure waveform (FloTrac/Vigileo; Edwards Lifesciences, Irvine, CA) is now approved for use in adults but not in children. This device is minimally invasive, calculates cardiac output continuously and in real time, and is easy to use. Our study sought to validate the FloTrac with the pulmonary artery catheter (PAC) intermittent thermodilution technique in pediatric cardiac patients.
Methods: This was a prospective pilot study comparing cardiac output measurements obtained via the FloTrac and arterial pressure waveform analysis with intermittent thermodilution. Subjects carried the diagnosis of pulmonary hypertension or cardiomyopathy, or were in the postoperative course after orthotopic heart transplantation.
Results: Enrolled in the study were 31 subjects, and 136 data points were obtained. The age range was 8 months to 16 years. The mean body surface area (BSA) was 1.1 m(2). Bland-Altman plots for the mean cardiac outputs of all subjects with a BSA ≥ 1 m(2) showed limits of agreement of -2.7 to 8.0 l/min (± 5.4 l/min). Patients with a BSA ≤ 1 m(2) demonstrated even wider limits of agreement (± 8.5 l/min). The intraclass correlation for the PAC was 0.929 and 0.992 for the FloTrac.
Conclusion: There was poor agreement between the PAC and FloTrac in measuring cardiac output in a population of children with pulmonary hypertension or cardiomyopathy, or after cardiac transplantation. This is in contrast to adult studies published thus far. This suggests that the utility of the FloTrac and measurements obtained from arterial pulse wave analysis in children is uncertain at this time.