Hemodynamic pressure waveform analysis in predicting fluid responsiveness

Abstract

Objective: To assess the usefulness of central venous pressure (CVP), diastolic right ventricular pressure, and pulmonary capillary wedge pressure (PCWP) waveform analysis in predicting fluid responsiveness.

Design: A prospective observational study.

Setting: Tertiary care university hospital.

Patients: Forty-four patients undergoing coronary artery bypass grafting.

Interventions: Analysis of the a/v wave ratio of the PCWP, CVP, and right ventricular dP/dt to predict an increase in stroke volume >15% after the administration of 500 mL of colloid.

Measurements and main results: Forty-four patients were enrolled in this study and 7 were excluded. There were 24 responders and 13 nonresponders. No differences in mean CVP and PCWP values between the responders and the nonresponders were found. The only parameter associated with a significant response to volume infusion was the ratio of the a/v waves of the PCWP tracing (p = 0.0001). The performance of the a/v wave ratio>1 of the PCWP tracing in predicting fluid responsiveness was evaluated by constructing a receiver operating characteristic curve. The area under the receiver operating characteristic curve was 0.89 (95% confidence interval, 0.79-0.99; p<0.05).

Conclusions: The a/v ratio measured on the PCWP tracing is a predictor of fluid responsiveness in patients with preserved left ventricular function undergoing coronary artery bypass grafting.

Keywords: a/c waves; cardiac surgery; hemodynamic monitoring; preload responsiveness; pulmonary artery pressures.